1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/mm/memory.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 61da177e4SLinus Torvalds */ 71da177e4SLinus Torvalds 81da177e4SLinus Torvalds /* 91da177e4SLinus Torvalds * demand-loading started 01.12.91 - seems it is high on the list of 101da177e4SLinus Torvalds * things wanted, and it should be easy to implement. - Linus 111da177e4SLinus Torvalds */ 121da177e4SLinus Torvalds 131da177e4SLinus Torvalds /* 141da177e4SLinus Torvalds * Ok, demand-loading was easy, shared pages a little bit tricker. Shared 151da177e4SLinus Torvalds * pages started 02.12.91, seems to work. - Linus. 161da177e4SLinus Torvalds * 171da177e4SLinus Torvalds * Tested sharing by executing about 30 /bin/sh: under the old kernel it 181da177e4SLinus Torvalds * would have taken more than the 6M I have free, but it worked well as 191da177e4SLinus Torvalds * far as I could see. 201da177e4SLinus Torvalds * 211da177e4SLinus Torvalds * Also corrected some "invalidate()"s - I wasn't doing enough of them. 221da177e4SLinus Torvalds */ 231da177e4SLinus Torvalds 241da177e4SLinus Torvalds /* 251da177e4SLinus Torvalds * Real VM (paging to/from disk) started 18.12.91. Much more work and 261da177e4SLinus Torvalds * thought has to go into this. Oh, well.. 271da177e4SLinus Torvalds * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why. 281da177e4SLinus Torvalds * Found it. Everything seems to work now. 291da177e4SLinus Torvalds * 20.12.91 - Ok, making the swap-device changeable like the root. 301da177e4SLinus Torvalds */ 311da177e4SLinus Torvalds 321da177e4SLinus Torvalds /* 331da177e4SLinus Torvalds * 05.04.94 - Multi-page memory management added for v1.1. 341da177e4SLinus Torvalds * Idea by Alex Bligh (alex@cconcepts.co.uk) 351da177e4SLinus Torvalds * 361da177e4SLinus Torvalds * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG 371da177e4SLinus Torvalds * (Gerhard.Wichert@pdb.siemens.de) 381da177e4SLinus Torvalds * 391da177e4SLinus Torvalds * Aug/Sep 2004 Changed to four level page tables (Andi Kleen) 401da177e4SLinus Torvalds */ 411da177e4SLinus Torvalds 421da177e4SLinus Torvalds #include <linux/kernel_stat.h> 431da177e4SLinus Torvalds #include <linux/mm.h> 446e84f315SIngo Molnar #include <linux/sched/mm.h> 45f7ccbae4SIngo Molnar #include <linux/sched/coredump.h> 466a3827d7SIngo Molnar #include <linux/sched/numa_balancing.h> 4729930025SIngo Molnar #include <linux/sched/task.h> 481da177e4SLinus Torvalds #include <linux/hugetlb.h> 491da177e4SLinus Torvalds #include <linux/mman.h> 501da177e4SLinus Torvalds #include <linux/swap.h> 511da177e4SLinus Torvalds #include <linux/highmem.h> 521da177e4SLinus Torvalds #include <linux/pagemap.h> 535042db43SJérôme Glisse #include <linux/memremap.h> 549a840895SHugh Dickins #include <linux/ksm.h> 551da177e4SLinus Torvalds #include <linux/rmap.h> 56b95f1b31SPaul Gortmaker #include <linux/export.h> 570ff92245SShailabh Nagar #include <linux/delayacct.h> 581da177e4SLinus Torvalds #include <linux/init.h> 5901c8f1c4SDan Williams #include <linux/pfn_t.h> 60edc79b2aSPeter Zijlstra #include <linux/writeback.h> 618a9f3ccdSBalbir Singh #include <linux/memcontrol.h> 62cddb8a5cSAndrea Arcangeli #include <linux/mmu_notifier.h> 633dc14741SHugh Dickins #include <linux/swapops.h> 643dc14741SHugh Dickins #include <linux/elf.h> 655a0e3ad6STejun Heo #include <linux/gfp.h> 664daae3b4SMel Gorman #include <linux/migrate.h> 672fbc57c5SAndy Shevchenko #include <linux/string.h> 681592eef0SKirill A. Shutemov #include <linux/debugfs.h> 696b251fc9SAndrea Arcangeli #include <linux/userfaultfd_k.h> 70bc2466e4SJan Kara #include <linux/dax.h> 716b31d595SMichal Hocko #include <linux/oom.h> 7298fa15f3SAnshuman Khandual #include <linux/numa.h> 73bce617edSPeter Xu #include <linux/perf_event.h> 74bce617edSPeter Xu #include <linux/ptrace.h> 75e80d3909SJoerg Roedel #include <linux/vmalloc.h> 761da177e4SLinus Torvalds 77b3d1411bSJoel Fernandes (Google) #include <trace/events/kmem.h> 78b3d1411bSJoel Fernandes (Google) 796952b61dSAlexey Dobriyan #include <asm/io.h> 8033a709b2SDave Hansen #include <asm/mmu_context.h> 811da177e4SLinus Torvalds #include <asm/pgalloc.h> 827c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 831da177e4SLinus Torvalds #include <asm/tlb.h> 841da177e4SLinus Torvalds #include <asm/tlbflush.h> 851da177e4SLinus Torvalds 86e80d3909SJoerg Roedel #include "pgalloc-track.h" 8742b77728SJan Beulich #include "internal.h" 8842b77728SJan Beulich 89af27d940SArnd Bergmann #if defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS) && !defined(CONFIG_COMPILE_TEST) 9090572890SPeter Zijlstra #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. 9175980e97SPeter Zijlstra #endif 9275980e97SPeter Zijlstra 93d41dee36SAndy Whitcroft #ifndef CONFIG_NEED_MULTIPLE_NODES 941da177e4SLinus Torvalds /* use the per-pgdat data instead for discontigmem - mbligh */ 951da177e4SLinus Torvalds unsigned long max_mapnr; 961da177e4SLinus Torvalds EXPORT_SYMBOL(max_mapnr); 97166f61b9STobin C Harding 98166f61b9STobin C Harding struct page *mem_map; 991da177e4SLinus Torvalds EXPORT_SYMBOL(mem_map); 1001da177e4SLinus Torvalds #endif 1011da177e4SLinus Torvalds 1021da177e4SLinus Torvalds /* 1031da177e4SLinus Torvalds * A number of key systems in x86 including ioremap() rely on the assumption 1041da177e4SLinus Torvalds * that high_memory defines the upper bound on direct map memory, then end 1051da177e4SLinus Torvalds * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and 1061da177e4SLinus Torvalds * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL 1071da177e4SLinus Torvalds * and ZONE_HIGHMEM. 1081da177e4SLinus Torvalds */ 1091da177e4SLinus Torvalds void *high_memory; 1101da177e4SLinus Torvalds EXPORT_SYMBOL(high_memory); 1111da177e4SLinus Torvalds 11232a93233SIngo Molnar /* 11332a93233SIngo Molnar * Randomize the address space (stacks, mmaps, brk, etc.). 11432a93233SIngo Molnar * 11532a93233SIngo Molnar * ( When CONFIG_COMPAT_BRK=y we exclude brk from randomization, 11632a93233SIngo Molnar * as ancient (libc5 based) binaries can segfault. ) 11732a93233SIngo Molnar */ 11832a93233SIngo Molnar int randomize_va_space __read_mostly = 11932a93233SIngo Molnar #ifdef CONFIG_COMPAT_BRK 12032a93233SIngo Molnar 1; 12132a93233SIngo Molnar #else 12232a93233SIngo Molnar 2; 12332a93233SIngo Molnar #endif 124a62eaf15SAndi Kleen 12583d116c5SJia He #ifndef arch_faults_on_old_pte 12683d116c5SJia He static inline bool arch_faults_on_old_pte(void) 12783d116c5SJia He { 12883d116c5SJia He /* 12983d116c5SJia He * Those arches which don't have hw access flag feature need to 13083d116c5SJia He * implement their own helper. By default, "true" means pagefault 13183d116c5SJia He * will be hit on old pte. 13283d116c5SJia He */ 13383d116c5SJia He return true; 13483d116c5SJia He } 13583d116c5SJia He #endif 13683d116c5SJia He 13746bdb427SWill Deacon #ifndef arch_wants_old_prefaulted_pte 13846bdb427SWill Deacon static inline bool arch_wants_old_prefaulted_pte(void) 13946bdb427SWill Deacon { 14046bdb427SWill Deacon /* 14146bdb427SWill Deacon * Transitioning a PTE from 'old' to 'young' can be expensive on 14246bdb427SWill Deacon * some architectures, even if it's performed in hardware. By 14346bdb427SWill Deacon * default, "false" means prefaulted entries will be 'young'. 14446bdb427SWill Deacon */ 14546bdb427SWill Deacon return false; 14646bdb427SWill Deacon } 14746bdb427SWill Deacon #endif 14846bdb427SWill Deacon 149a62eaf15SAndi Kleen static int __init disable_randmaps(char *s) 150a62eaf15SAndi Kleen { 151a62eaf15SAndi Kleen randomize_va_space = 0; 1529b41046cSOGAWA Hirofumi return 1; 153a62eaf15SAndi Kleen } 154a62eaf15SAndi Kleen __setup("norandmaps", disable_randmaps); 155a62eaf15SAndi Kleen 15662eede62SHugh Dickins unsigned long zero_pfn __read_mostly; 1570b70068eSArd Biesheuvel EXPORT_SYMBOL(zero_pfn); 1580b70068eSArd Biesheuvel 159166f61b9STobin C Harding unsigned long highest_memmap_pfn __read_mostly; 160166f61b9STobin C Harding 161a13ea5b7SHugh Dickins /* 162a13ea5b7SHugh Dickins * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init() 163a13ea5b7SHugh Dickins */ 164a13ea5b7SHugh Dickins static int __init init_zero_pfn(void) 165a13ea5b7SHugh Dickins { 166a13ea5b7SHugh Dickins zero_pfn = page_to_pfn(ZERO_PAGE(0)); 167a13ea5b7SHugh Dickins return 0; 168a13ea5b7SHugh Dickins } 169e720e7d0SIlya Lipnitskiy early_initcall(init_zero_pfn); 170a62eaf15SAndi Kleen 171e4dcad20SJoel Fernandes (Google) void mm_trace_rss_stat(struct mm_struct *mm, int member, long count) 172b3d1411bSJoel Fernandes (Google) { 173e4dcad20SJoel Fernandes (Google) trace_rss_stat(mm, member, count); 174b3d1411bSJoel Fernandes (Google) } 175d559db08SKAMEZAWA Hiroyuki 17634e55232SKAMEZAWA Hiroyuki #if defined(SPLIT_RSS_COUNTING) 17734e55232SKAMEZAWA Hiroyuki 178ea48cf78SDavid Rientjes void sync_mm_rss(struct mm_struct *mm) 17934e55232SKAMEZAWA Hiroyuki { 18034e55232SKAMEZAWA Hiroyuki int i; 18134e55232SKAMEZAWA Hiroyuki 18234e55232SKAMEZAWA Hiroyuki for (i = 0; i < NR_MM_COUNTERS; i++) { 18305af2e10SDavid Rientjes if (current->rss_stat.count[i]) { 18405af2e10SDavid Rientjes add_mm_counter(mm, i, current->rss_stat.count[i]); 18505af2e10SDavid Rientjes current->rss_stat.count[i] = 0; 18634e55232SKAMEZAWA Hiroyuki } 18734e55232SKAMEZAWA Hiroyuki } 18805af2e10SDavid Rientjes current->rss_stat.events = 0; 18934e55232SKAMEZAWA Hiroyuki } 19034e55232SKAMEZAWA Hiroyuki 19134e55232SKAMEZAWA Hiroyuki static void add_mm_counter_fast(struct mm_struct *mm, int member, int val) 19234e55232SKAMEZAWA Hiroyuki { 19334e55232SKAMEZAWA Hiroyuki struct task_struct *task = current; 19434e55232SKAMEZAWA Hiroyuki 19534e55232SKAMEZAWA Hiroyuki if (likely(task->mm == mm)) 19634e55232SKAMEZAWA Hiroyuki task->rss_stat.count[member] += val; 19734e55232SKAMEZAWA Hiroyuki else 19834e55232SKAMEZAWA Hiroyuki add_mm_counter(mm, member, val); 19934e55232SKAMEZAWA Hiroyuki } 20034e55232SKAMEZAWA Hiroyuki #define inc_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, 1) 20134e55232SKAMEZAWA Hiroyuki #define dec_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, -1) 20234e55232SKAMEZAWA Hiroyuki 20334e55232SKAMEZAWA Hiroyuki /* sync counter once per 64 page faults */ 20434e55232SKAMEZAWA Hiroyuki #define TASK_RSS_EVENTS_THRESH (64) 20534e55232SKAMEZAWA Hiroyuki static void check_sync_rss_stat(struct task_struct *task) 20634e55232SKAMEZAWA Hiroyuki { 20734e55232SKAMEZAWA Hiroyuki if (unlikely(task != current)) 20834e55232SKAMEZAWA Hiroyuki return; 20934e55232SKAMEZAWA Hiroyuki if (unlikely(task->rss_stat.events++ > TASK_RSS_EVENTS_THRESH)) 210ea48cf78SDavid Rientjes sync_mm_rss(task->mm); 21134e55232SKAMEZAWA Hiroyuki } 2129547d01bSPeter Zijlstra #else /* SPLIT_RSS_COUNTING */ 21334e55232SKAMEZAWA Hiroyuki 21434e55232SKAMEZAWA Hiroyuki #define inc_mm_counter_fast(mm, member) inc_mm_counter(mm, member) 21534e55232SKAMEZAWA Hiroyuki #define dec_mm_counter_fast(mm, member) dec_mm_counter(mm, member) 21634e55232SKAMEZAWA Hiroyuki 21734e55232SKAMEZAWA Hiroyuki static void check_sync_rss_stat(struct task_struct *task) 21834e55232SKAMEZAWA Hiroyuki { 21934e55232SKAMEZAWA Hiroyuki } 22034e55232SKAMEZAWA Hiroyuki 2219547d01bSPeter Zijlstra #endif /* SPLIT_RSS_COUNTING */ 2229547d01bSPeter Zijlstra 2231da177e4SLinus Torvalds /* 2241da177e4SLinus Torvalds * Note: this doesn't free the actual pages themselves. That 2251da177e4SLinus Torvalds * has been handled earlier when unmapping all the memory regions. 2261da177e4SLinus Torvalds */ 2279e1b32caSBenjamin Herrenschmidt static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd, 2289e1b32caSBenjamin Herrenschmidt unsigned long addr) 2291da177e4SLinus Torvalds { 2302f569afdSMartin Schwidefsky pgtable_t token = pmd_pgtable(*pmd); 2311da177e4SLinus Torvalds pmd_clear(pmd); 2329e1b32caSBenjamin Herrenschmidt pte_free_tlb(tlb, token, addr); 233c4812909SKirill A. Shutemov mm_dec_nr_ptes(tlb->mm); 2341da177e4SLinus Torvalds } 2351da177e4SLinus Torvalds 236e0da382cSHugh Dickins static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud, 237e0da382cSHugh Dickins unsigned long addr, unsigned long end, 238e0da382cSHugh Dickins unsigned long floor, unsigned long ceiling) 2391da177e4SLinus Torvalds { 2401da177e4SLinus Torvalds pmd_t *pmd; 2411da177e4SLinus Torvalds unsigned long next; 242e0da382cSHugh Dickins unsigned long start; 2431da177e4SLinus Torvalds 244e0da382cSHugh Dickins start = addr; 2451da177e4SLinus Torvalds pmd = pmd_offset(pud, addr); 2461da177e4SLinus Torvalds do { 2471da177e4SLinus Torvalds next = pmd_addr_end(addr, end); 2481da177e4SLinus Torvalds if (pmd_none_or_clear_bad(pmd)) 2491da177e4SLinus Torvalds continue; 2509e1b32caSBenjamin Herrenschmidt free_pte_range(tlb, pmd, addr); 2511da177e4SLinus Torvalds } while (pmd++, addr = next, addr != end); 2521da177e4SLinus Torvalds 253e0da382cSHugh Dickins start &= PUD_MASK; 254e0da382cSHugh Dickins if (start < floor) 255e0da382cSHugh Dickins return; 256e0da382cSHugh Dickins if (ceiling) { 257e0da382cSHugh Dickins ceiling &= PUD_MASK; 258e0da382cSHugh Dickins if (!ceiling) 259e0da382cSHugh Dickins return; 2601da177e4SLinus Torvalds } 261e0da382cSHugh Dickins if (end - 1 > ceiling - 1) 262e0da382cSHugh Dickins return; 263e0da382cSHugh Dickins 264e0da382cSHugh Dickins pmd = pmd_offset(pud, start); 265e0da382cSHugh Dickins pud_clear(pud); 2669e1b32caSBenjamin Herrenschmidt pmd_free_tlb(tlb, pmd, start); 267dc6c9a35SKirill A. Shutemov mm_dec_nr_pmds(tlb->mm); 2681da177e4SLinus Torvalds } 2691da177e4SLinus Torvalds 270c2febafcSKirill A. Shutemov static inline void free_pud_range(struct mmu_gather *tlb, p4d_t *p4d, 271e0da382cSHugh Dickins unsigned long addr, unsigned long end, 272e0da382cSHugh Dickins unsigned long floor, unsigned long ceiling) 2731da177e4SLinus Torvalds { 2741da177e4SLinus Torvalds pud_t *pud; 2751da177e4SLinus Torvalds unsigned long next; 276e0da382cSHugh Dickins unsigned long start; 2771da177e4SLinus Torvalds 278e0da382cSHugh Dickins start = addr; 279c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 2801da177e4SLinus Torvalds do { 2811da177e4SLinus Torvalds next = pud_addr_end(addr, end); 2821da177e4SLinus Torvalds if (pud_none_or_clear_bad(pud)) 2831da177e4SLinus Torvalds continue; 284e0da382cSHugh Dickins free_pmd_range(tlb, pud, addr, next, floor, ceiling); 2851da177e4SLinus Torvalds } while (pud++, addr = next, addr != end); 2861da177e4SLinus Torvalds 287c2febafcSKirill A. Shutemov start &= P4D_MASK; 288c2febafcSKirill A. Shutemov if (start < floor) 289c2febafcSKirill A. Shutemov return; 290c2febafcSKirill A. Shutemov if (ceiling) { 291c2febafcSKirill A. Shutemov ceiling &= P4D_MASK; 292c2febafcSKirill A. Shutemov if (!ceiling) 293c2febafcSKirill A. Shutemov return; 294c2febafcSKirill A. Shutemov } 295c2febafcSKirill A. Shutemov if (end - 1 > ceiling - 1) 296c2febafcSKirill A. Shutemov return; 297c2febafcSKirill A. Shutemov 298c2febafcSKirill A. Shutemov pud = pud_offset(p4d, start); 299c2febafcSKirill A. Shutemov p4d_clear(p4d); 300c2febafcSKirill A. Shutemov pud_free_tlb(tlb, pud, start); 301b4e98d9aSKirill A. Shutemov mm_dec_nr_puds(tlb->mm); 302c2febafcSKirill A. Shutemov } 303c2febafcSKirill A. Shutemov 304c2febafcSKirill A. Shutemov static inline void free_p4d_range(struct mmu_gather *tlb, pgd_t *pgd, 305c2febafcSKirill A. Shutemov unsigned long addr, unsigned long end, 306c2febafcSKirill A. Shutemov unsigned long floor, unsigned long ceiling) 307c2febafcSKirill A. Shutemov { 308c2febafcSKirill A. Shutemov p4d_t *p4d; 309c2febafcSKirill A. Shutemov unsigned long next; 310c2febafcSKirill A. Shutemov unsigned long start; 311c2febafcSKirill A. Shutemov 312c2febafcSKirill A. Shutemov start = addr; 313c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 314c2febafcSKirill A. Shutemov do { 315c2febafcSKirill A. Shutemov next = p4d_addr_end(addr, end); 316c2febafcSKirill A. Shutemov if (p4d_none_or_clear_bad(p4d)) 317c2febafcSKirill A. Shutemov continue; 318c2febafcSKirill A. Shutemov free_pud_range(tlb, p4d, addr, next, floor, ceiling); 319c2febafcSKirill A. Shutemov } while (p4d++, addr = next, addr != end); 320c2febafcSKirill A. Shutemov 321e0da382cSHugh Dickins start &= PGDIR_MASK; 322e0da382cSHugh Dickins if (start < floor) 323e0da382cSHugh Dickins return; 324e0da382cSHugh Dickins if (ceiling) { 325e0da382cSHugh Dickins ceiling &= PGDIR_MASK; 326e0da382cSHugh Dickins if (!ceiling) 327e0da382cSHugh Dickins return; 3281da177e4SLinus Torvalds } 329e0da382cSHugh Dickins if (end - 1 > ceiling - 1) 330e0da382cSHugh Dickins return; 331e0da382cSHugh Dickins 332c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, start); 333e0da382cSHugh Dickins pgd_clear(pgd); 334c2febafcSKirill A. Shutemov p4d_free_tlb(tlb, p4d, start); 3351da177e4SLinus Torvalds } 3361da177e4SLinus Torvalds 3371da177e4SLinus Torvalds /* 338e0da382cSHugh Dickins * This function frees user-level page tables of a process. 3391da177e4SLinus Torvalds */ 34042b77728SJan Beulich void free_pgd_range(struct mmu_gather *tlb, 341e0da382cSHugh Dickins unsigned long addr, unsigned long end, 342e0da382cSHugh Dickins unsigned long floor, unsigned long ceiling) 3431da177e4SLinus Torvalds { 3441da177e4SLinus Torvalds pgd_t *pgd; 3451da177e4SLinus Torvalds unsigned long next; 3461da177e4SLinus Torvalds 347e0da382cSHugh Dickins /* 348e0da382cSHugh Dickins * The next few lines have given us lots of grief... 349e0da382cSHugh Dickins * 350e0da382cSHugh Dickins * Why are we testing PMD* at this top level? Because often 351e0da382cSHugh Dickins * there will be no work to do at all, and we'd prefer not to 352e0da382cSHugh Dickins * go all the way down to the bottom just to discover that. 353e0da382cSHugh Dickins * 354e0da382cSHugh Dickins * Why all these "- 1"s? Because 0 represents both the bottom 355e0da382cSHugh Dickins * of the address space and the top of it (using -1 for the 356e0da382cSHugh Dickins * top wouldn't help much: the masks would do the wrong thing). 357e0da382cSHugh Dickins * The rule is that addr 0 and floor 0 refer to the bottom of 358e0da382cSHugh Dickins * the address space, but end 0 and ceiling 0 refer to the top 359e0da382cSHugh Dickins * Comparisons need to use "end - 1" and "ceiling - 1" (though 360e0da382cSHugh Dickins * that end 0 case should be mythical). 361e0da382cSHugh Dickins * 362e0da382cSHugh Dickins * Wherever addr is brought up or ceiling brought down, we must 363e0da382cSHugh Dickins * be careful to reject "the opposite 0" before it confuses the 364e0da382cSHugh Dickins * subsequent tests. But what about where end is brought down 365e0da382cSHugh Dickins * by PMD_SIZE below? no, end can't go down to 0 there. 366e0da382cSHugh Dickins * 367e0da382cSHugh Dickins * Whereas we round start (addr) and ceiling down, by different 368e0da382cSHugh Dickins * masks at different levels, in order to test whether a table 369e0da382cSHugh Dickins * now has no other vmas using it, so can be freed, we don't 370e0da382cSHugh Dickins * bother to round floor or end up - the tests don't need that. 371e0da382cSHugh Dickins */ 372e0da382cSHugh Dickins 373e0da382cSHugh Dickins addr &= PMD_MASK; 374e0da382cSHugh Dickins if (addr < floor) { 375e0da382cSHugh Dickins addr += PMD_SIZE; 376e0da382cSHugh Dickins if (!addr) 377e0da382cSHugh Dickins return; 378e0da382cSHugh Dickins } 379e0da382cSHugh Dickins if (ceiling) { 380e0da382cSHugh Dickins ceiling &= PMD_MASK; 381e0da382cSHugh Dickins if (!ceiling) 382e0da382cSHugh Dickins return; 383e0da382cSHugh Dickins } 384e0da382cSHugh Dickins if (end - 1 > ceiling - 1) 385e0da382cSHugh Dickins end -= PMD_SIZE; 386e0da382cSHugh Dickins if (addr > end - 1) 387e0da382cSHugh Dickins return; 38807e32661SAneesh Kumar K.V /* 38907e32661SAneesh Kumar K.V * We add page table cache pages with PAGE_SIZE, 39007e32661SAneesh Kumar K.V * (see pte_free_tlb()), flush the tlb if we need 39107e32661SAneesh Kumar K.V */ 392ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, PAGE_SIZE); 39342b77728SJan Beulich pgd = pgd_offset(tlb->mm, addr); 3941da177e4SLinus Torvalds do { 3951da177e4SLinus Torvalds next = pgd_addr_end(addr, end); 3961da177e4SLinus Torvalds if (pgd_none_or_clear_bad(pgd)) 3971da177e4SLinus Torvalds continue; 398c2febafcSKirill A. Shutemov free_p4d_range(tlb, pgd, addr, next, floor, ceiling); 3991da177e4SLinus Torvalds } while (pgd++, addr = next, addr != end); 400e0da382cSHugh Dickins } 401e0da382cSHugh Dickins 40242b77728SJan Beulich void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma, 403e0da382cSHugh Dickins unsigned long floor, unsigned long ceiling) 404e0da382cSHugh Dickins { 405e0da382cSHugh Dickins while (vma) { 406e0da382cSHugh Dickins struct vm_area_struct *next = vma->vm_next; 407e0da382cSHugh Dickins unsigned long addr = vma->vm_start; 408e0da382cSHugh Dickins 4098f4f8c16SHugh Dickins /* 41025d9e2d1Snpiggin@suse.de * Hide vma from rmap and truncate_pagecache before freeing 41125d9e2d1Snpiggin@suse.de * pgtables 4128f4f8c16SHugh Dickins */ 4135beb4930SRik van Riel unlink_anon_vmas(vma); 4148f4f8c16SHugh Dickins unlink_file_vma(vma); 4158f4f8c16SHugh Dickins 4169da61aefSDavid Gibson if (is_vm_hugetlb_page(vma)) { 4173bf5ee95SHugh Dickins hugetlb_free_pgd_range(tlb, addr, vma->vm_end, 4183bf5ee95SHugh Dickins floor, next ? next->vm_start : ceiling); 4193bf5ee95SHugh Dickins } else { 4203bf5ee95SHugh Dickins /* 4213bf5ee95SHugh Dickins * Optimization: gather nearby vmas into one call down 4223bf5ee95SHugh Dickins */ 4233bf5ee95SHugh Dickins while (next && next->vm_start <= vma->vm_end + PMD_SIZE 4244866920bSDavid Gibson && !is_vm_hugetlb_page(next)) { 425e0da382cSHugh Dickins vma = next; 426e0da382cSHugh Dickins next = vma->vm_next; 4275beb4930SRik van Riel unlink_anon_vmas(vma); 4288f4f8c16SHugh Dickins unlink_file_vma(vma); 429e0da382cSHugh Dickins } 4303bf5ee95SHugh Dickins free_pgd_range(tlb, addr, vma->vm_end, 431e0da382cSHugh Dickins floor, next ? next->vm_start : ceiling); 4323bf5ee95SHugh Dickins } 433e0da382cSHugh Dickins vma = next; 434e0da382cSHugh Dickins } 4351da177e4SLinus Torvalds } 4361da177e4SLinus Torvalds 4374cf58924SJoel Fernandes (Google) int __pte_alloc(struct mm_struct *mm, pmd_t *pmd) 4381da177e4SLinus Torvalds { 439c4088ebdSKirill A. Shutemov spinlock_t *ptl; 4404cf58924SJoel Fernandes (Google) pgtable_t new = pte_alloc_one(mm); 4411da177e4SLinus Torvalds if (!new) 4421bb3630eSHugh Dickins return -ENOMEM; 4431bb3630eSHugh Dickins 444362a61adSNick Piggin /* 445362a61adSNick Piggin * Ensure all pte setup (eg. pte page lock and page clearing) are 446362a61adSNick Piggin * visible before the pte is made visible to other CPUs by being 447362a61adSNick Piggin * put into page tables. 448362a61adSNick Piggin * 449362a61adSNick Piggin * The other side of the story is the pointer chasing in the page 450362a61adSNick Piggin * table walking code (when walking the page table without locking; 451362a61adSNick Piggin * ie. most of the time). Fortunately, these data accesses consist 452362a61adSNick Piggin * of a chain of data-dependent loads, meaning most CPUs (alpha 453362a61adSNick Piggin * being the notable exception) will already guarantee loads are 454362a61adSNick Piggin * seen in-order. See the alpha page table accessors for the 455bb7cdd38SWill Deacon * smp_rmb() barriers in page table walking code. 456362a61adSNick Piggin */ 457362a61adSNick Piggin smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */ 458362a61adSNick Piggin 459c4088ebdSKirill A. Shutemov ptl = pmd_lock(mm, pmd); 4608ac1f832SAndrea Arcangeli if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ 461c4812909SKirill A. Shutemov mm_inc_nr_ptes(mm); 4621da177e4SLinus Torvalds pmd_populate(mm, pmd, new); 4632f569afdSMartin Schwidefsky new = NULL; 4644b471e88SKirill A. Shutemov } 465c4088ebdSKirill A. Shutemov spin_unlock(ptl); 4662f569afdSMartin Schwidefsky if (new) 4672f569afdSMartin Schwidefsky pte_free(mm, new); 4681bb3630eSHugh Dickins return 0; 4691da177e4SLinus Torvalds } 4701da177e4SLinus Torvalds 4714cf58924SJoel Fernandes (Google) int __pte_alloc_kernel(pmd_t *pmd) 4721da177e4SLinus Torvalds { 4734cf58924SJoel Fernandes (Google) pte_t *new = pte_alloc_one_kernel(&init_mm); 4741da177e4SLinus Torvalds if (!new) 4751bb3630eSHugh Dickins return -ENOMEM; 4761da177e4SLinus Torvalds 477362a61adSNick Piggin smp_wmb(); /* See comment in __pte_alloc */ 478362a61adSNick Piggin 479872fec16SHugh Dickins spin_lock(&init_mm.page_table_lock); 4808ac1f832SAndrea Arcangeli if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ 481872fec16SHugh Dickins pmd_populate_kernel(&init_mm, pmd, new); 4822f569afdSMartin Schwidefsky new = NULL; 4834b471e88SKirill A. Shutemov } 484872fec16SHugh Dickins spin_unlock(&init_mm.page_table_lock); 4852f569afdSMartin Schwidefsky if (new) 4862f569afdSMartin Schwidefsky pte_free_kernel(&init_mm, new); 4871bb3630eSHugh Dickins return 0; 4881da177e4SLinus Torvalds } 4891da177e4SLinus Torvalds 490d559db08SKAMEZAWA Hiroyuki static inline void init_rss_vec(int *rss) 491ae859762SHugh Dickins { 492d559db08SKAMEZAWA Hiroyuki memset(rss, 0, sizeof(int) * NR_MM_COUNTERS); 493d559db08SKAMEZAWA Hiroyuki } 494d559db08SKAMEZAWA Hiroyuki 495d559db08SKAMEZAWA Hiroyuki static inline void add_mm_rss_vec(struct mm_struct *mm, int *rss) 496d559db08SKAMEZAWA Hiroyuki { 497d559db08SKAMEZAWA Hiroyuki int i; 498d559db08SKAMEZAWA Hiroyuki 49934e55232SKAMEZAWA Hiroyuki if (current->mm == mm) 50005af2e10SDavid Rientjes sync_mm_rss(mm); 501d559db08SKAMEZAWA Hiroyuki for (i = 0; i < NR_MM_COUNTERS; i++) 502d559db08SKAMEZAWA Hiroyuki if (rss[i]) 503d559db08SKAMEZAWA Hiroyuki add_mm_counter(mm, i, rss[i]); 504ae859762SHugh Dickins } 505ae859762SHugh Dickins 5061da177e4SLinus Torvalds /* 5076aab341eSLinus Torvalds * This function is called to print an error when a bad pte 5086aab341eSLinus Torvalds * is found. For example, we might have a PFN-mapped pte in 5096aab341eSLinus Torvalds * a region that doesn't allow it. 510b5810039SNick Piggin * 511b5810039SNick Piggin * The calling function must still handle the error. 512b5810039SNick Piggin */ 5133dc14741SHugh Dickins static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr, 5143dc14741SHugh Dickins pte_t pte, struct page *page) 515b5810039SNick Piggin { 5163dc14741SHugh Dickins pgd_t *pgd = pgd_offset(vma->vm_mm, addr); 517c2febafcSKirill A. Shutemov p4d_t *p4d = p4d_offset(pgd, addr); 518c2febafcSKirill A. Shutemov pud_t *pud = pud_offset(p4d, addr); 5193dc14741SHugh Dickins pmd_t *pmd = pmd_offset(pud, addr); 5203dc14741SHugh Dickins struct address_space *mapping; 5213dc14741SHugh Dickins pgoff_t index; 522d936cf9bSHugh Dickins static unsigned long resume; 523d936cf9bSHugh Dickins static unsigned long nr_shown; 524d936cf9bSHugh Dickins static unsigned long nr_unshown; 525d936cf9bSHugh Dickins 526d936cf9bSHugh Dickins /* 527d936cf9bSHugh Dickins * Allow a burst of 60 reports, then keep quiet for that minute; 528d936cf9bSHugh Dickins * or allow a steady drip of one report per second. 529d936cf9bSHugh Dickins */ 530d936cf9bSHugh Dickins if (nr_shown == 60) { 531d936cf9bSHugh Dickins if (time_before(jiffies, resume)) { 532d936cf9bSHugh Dickins nr_unshown++; 533d936cf9bSHugh Dickins return; 534d936cf9bSHugh Dickins } 535d936cf9bSHugh Dickins if (nr_unshown) { 5361170532bSJoe Perches pr_alert("BUG: Bad page map: %lu messages suppressed\n", 537d936cf9bSHugh Dickins nr_unshown); 538d936cf9bSHugh Dickins nr_unshown = 0; 539d936cf9bSHugh Dickins } 540d936cf9bSHugh Dickins nr_shown = 0; 541d936cf9bSHugh Dickins } 542d936cf9bSHugh Dickins if (nr_shown++ == 0) 543d936cf9bSHugh Dickins resume = jiffies + 60 * HZ; 5443dc14741SHugh Dickins 5453dc14741SHugh Dickins mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL; 5463dc14741SHugh Dickins index = linear_page_index(vma, addr); 5473dc14741SHugh Dickins 5481170532bSJoe Perches pr_alert("BUG: Bad page map in process %s pte:%08llx pmd:%08llx\n", 5493dc14741SHugh Dickins current->comm, 5503dc14741SHugh Dickins (long long)pte_val(pte), (long long)pmd_val(*pmd)); 551718a3821SWu Fengguang if (page) 552f0b791a3SDave Hansen dump_page(page, "bad pte"); 5536aa9b8b2SKefeng Wang pr_alert("addr:%px vm_flags:%08lx anon_vma:%px mapping:%px index:%lx\n", 5543dc14741SHugh Dickins (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index); 555d75f773cSSakari Ailus pr_alert("file:%pD fault:%ps mmap:%ps readpage:%ps\n", 5562682582aSKonstantin Khlebnikov vma->vm_file, 5572682582aSKonstantin Khlebnikov vma->vm_ops ? vma->vm_ops->fault : NULL, 5582682582aSKonstantin Khlebnikov vma->vm_file ? vma->vm_file->f_op->mmap : NULL, 5592682582aSKonstantin Khlebnikov mapping ? mapping->a_ops->readpage : NULL); 560b5810039SNick Piggin dump_stack(); 561373d4d09SRusty Russell add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); 562b5810039SNick Piggin } 563b5810039SNick Piggin 564b5810039SNick Piggin /* 5657e675137SNick Piggin * vm_normal_page -- This function gets the "struct page" associated with a pte. 5666aab341eSLinus Torvalds * 5677e675137SNick Piggin * "Special" mappings do not wish to be associated with a "struct page" (either 5687e675137SNick Piggin * it doesn't exist, or it exists but they don't want to touch it). In this 5697e675137SNick Piggin * case, NULL is returned here. "Normal" mappings do have a struct page. 570b379d790SJared Hulbert * 5717e675137SNick Piggin * There are 2 broad cases. Firstly, an architecture may define a pte_special() 5727e675137SNick Piggin * pte bit, in which case this function is trivial. Secondly, an architecture 5737e675137SNick Piggin * may not have a spare pte bit, which requires a more complicated scheme, 5747e675137SNick Piggin * described below. 5757e675137SNick Piggin * 5767e675137SNick Piggin * A raw VM_PFNMAP mapping (ie. one that is not COWed) is always considered a 5777e675137SNick Piggin * special mapping (even if there are underlying and valid "struct pages"). 5787e675137SNick Piggin * COWed pages of a VM_PFNMAP are always normal. 5796aab341eSLinus Torvalds * 580b379d790SJared Hulbert * The way we recognize COWed pages within VM_PFNMAP mappings is through the 581b379d790SJared Hulbert * rules set up by "remap_pfn_range()": the vma will have the VM_PFNMAP bit 5827e675137SNick Piggin * set, and the vm_pgoff will point to the first PFN mapped: thus every special 5837e675137SNick Piggin * mapping will always honor the rule 5846aab341eSLinus Torvalds * 5856aab341eSLinus Torvalds * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT) 5866aab341eSLinus Torvalds * 5877e675137SNick Piggin * And for normal mappings this is false. 588b379d790SJared Hulbert * 5897e675137SNick Piggin * This restricts such mappings to be a linear translation from virtual address 5907e675137SNick Piggin * to pfn. To get around this restriction, we allow arbitrary mappings so long 5917e675137SNick Piggin * as the vma is not a COW mapping; in that case, we know that all ptes are 5927e675137SNick Piggin * special (because none can have been COWed). 593b379d790SJared Hulbert * 594b379d790SJared Hulbert * 5957e675137SNick Piggin * In order to support COW of arbitrary special mappings, we have VM_MIXEDMAP. 5967e675137SNick Piggin * 597b379d790SJared Hulbert * VM_MIXEDMAP mappings can likewise contain memory with or without "struct 598b379d790SJared Hulbert * page" backing, however the difference is that _all_ pages with a struct 599b379d790SJared Hulbert * page (that is, those where pfn_valid is true) are refcounted and considered 600b379d790SJared Hulbert * normal pages by the VM. The disadvantage is that pages are refcounted 601b379d790SJared Hulbert * (which can be slower and simply not an option for some PFNMAP users). The 602b379d790SJared Hulbert * advantage is that we don't have to follow the strict linearity rule of 603b379d790SJared Hulbert * PFNMAP mappings in order to support COWable mappings. 604b379d790SJared Hulbert * 605ee498ed7SHugh Dickins */ 60625b2995aSChristoph Hellwig struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, 60725b2995aSChristoph Hellwig pte_t pte) 608ee498ed7SHugh Dickins { 60922b31eecSHugh Dickins unsigned long pfn = pte_pfn(pte); 6107e675137SNick Piggin 61100b3a331SLaurent Dufour if (IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL)) { 612b38af472SHugh Dickins if (likely(!pte_special(pte))) 61322b31eecSHugh Dickins goto check_pfn; 614667a0a06SDavid Vrabel if (vma->vm_ops && vma->vm_ops->find_special_page) 615667a0a06SDavid Vrabel return vma->vm_ops->find_special_page(vma, addr); 616a13ea5b7SHugh Dickins if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) 617a13ea5b7SHugh Dickins return NULL; 618df6ad698SJérôme Glisse if (is_zero_pfn(pfn)) 619df6ad698SJérôme Glisse return NULL; 620e1fb4a08SDave Jiang if (pte_devmap(pte)) 621e1fb4a08SDave Jiang return NULL; 622e1fb4a08SDave Jiang 62322b31eecSHugh Dickins print_bad_pte(vma, addr, pte, NULL); 6247e675137SNick Piggin return NULL; 6257e675137SNick Piggin } 6267e675137SNick Piggin 62700b3a331SLaurent Dufour /* !CONFIG_ARCH_HAS_PTE_SPECIAL case follows: */ 6287e675137SNick Piggin 629b379d790SJared Hulbert if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) { 630b379d790SJared Hulbert if (vma->vm_flags & VM_MIXEDMAP) { 631b379d790SJared Hulbert if (!pfn_valid(pfn)) 632b379d790SJared Hulbert return NULL; 633b379d790SJared Hulbert goto out; 634b379d790SJared Hulbert } else { 6357e675137SNick Piggin unsigned long off; 6367e675137SNick Piggin off = (addr - vma->vm_start) >> PAGE_SHIFT; 6376aab341eSLinus Torvalds if (pfn == vma->vm_pgoff + off) 6386aab341eSLinus Torvalds return NULL; 63967121172SLinus Torvalds if (!is_cow_mapping(vma->vm_flags)) 640fb155c16SLinus Torvalds return NULL; 6416aab341eSLinus Torvalds } 642b379d790SJared Hulbert } 6436aab341eSLinus Torvalds 644b38af472SHugh Dickins if (is_zero_pfn(pfn)) 645b38af472SHugh Dickins return NULL; 64600b3a331SLaurent Dufour 64722b31eecSHugh Dickins check_pfn: 64822b31eecSHugh Dickins if (unlikely(pfn > highest_memmap_pfn)) { 64922b31eecSHugh Dickins print_bad_pte(vma, addr, pte, NULL); 65022b31eecSHugh Dickins return NULL; 65122b31eecSHugh Dickins } 6526aab341eSLinus Torvalds 6536aab341eSLinus Torvalds /* 6547e675137SNick Piggin * NOTE! We still have PageReserved() pages in the page tables. 6557e675137SNick Piggin * eg. VDSO mappings can cause them to exist. 6566aab341eSLinus Torvalds */ 657b379d790SJared Hulbert out: 6586aab341eSLinus Torvalds return pfn_to_page(pfn); 659ee498ed7SHugh Dickins } 660ee498ed7SHugh Dickins 66128093f9fSGerald Schaefer #ifdef CONFIG_TRANSPARENT_HUGEPAGE 66228093f9fSGerald Schaefer struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, 66328093f9fSGerald Schaefer pmd_t pmd) 66428093f9fSGerald Schaefer { 66528093f9fSGerald Schaefer unsigned long pfn = pmd_pfn(pmd); 66628093f9fSGerald Schaefer 66728093f9fSGerald Schaefer /* 66828093f9fSGerald Schaefer * There is no pmd_special() but there may be special pmds, e.g. 66928093f9fSGerald Schaefer * in a direct-access (dax) mapping, so let's just replicate the 67000b3a331SLaurent Dufour * !CONFIG_ARCH_HAS_PTE_SPECIAL case from vm_normal_page() here. 67128093f9fSGerald Schaefer */ 67228093f9fSGerald Schaefer if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) { 67328093f9fSGerald Schaefer if (vma->vm_flags & VM_MIXEDMAP) { 67428093f9fSGerald Schaefer if (!pfn_valid(pfn)) 67528093f9fSGerald Schaefer return NULL; 67628093f9fSGerald Schaefer goto out; 67728093f9fSGerald Schaefer } else { 67828093f9fSGerald Schaefer unsigned long off; 67928093f9fSGerald Schaefer off = (addr - vma->vm_start) >> PAGE_SHIFT; 68028093f9fSGerald Schaefer if (pfn == vma->vm_pgoff + off) 68128093f9fSGerald Schaefer return NULL; 68228093f9fSGerald Schaefer if (!is_cow_mapping(vma->vm_flags)) 68328093f9fSGerald Schaefer return NULL; 68428093f9fSGerald Schaefer } 68528093f9fSGerald Schaefer } 68628093f9fSGerald Schaefer 687e1fb4a08SDave Jiang if (pmd_devmap(pmd)) 688e1fb4a08SDave Jiang return NULL; 6893cde287bSYu Zhao if (is_huge_zero_pmd(pmd)) 69028093f9fSGerald Schaefer return NULL; 69128093f9fSGerald Schaefer if (unlikely(pfn > highest_memmap_pfn)) 69228093f9fSGerald Schaefer return NULL; 69328093f9fSGerald Schaefer 69428093f9fSGerald Schaefer /* 69528093f9fSGerald Schaefer * NOTE! We still have PageReserved() pages in the page tables. 69628093f9fSGerald Schaefer * eg. VDSO mappings can cause them to exist. 69728093f9fSGerald Schaefer */ 69828093f9fSGerald Schaefer out: 69928093f9fSGerald Schaefer return pfn_to_page(pfn); 70028093f9fSGerald Schaefer } 70128093f9fSGerald Schaefer #endif 70228093f9fSGerald Schaefer 703ee498ed7SHugh Dickins /* 7041da177e4SLinus Torvalds * copy one vm_area from one task to the other. Assumes the page tables 7051da177e4SLinus Torvalds * already present in the new task to be cleared in the whole range 7061da177e4SLinus Torvalds * covered by this vma. 7071da177e4SLinus Torvalds */ 7081da177e4SLinus Torvalds 709df3a57d1SLinus Torvalds static unsigned long 710df3a57d1SLinus Torvalds copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, 711b5810039SNick Piggin pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma, 7128c103762SHugh Dickins unsigned long addr, int *rss) 7131da177e4SLinus Torvalds { 714b5810039SNick Piggin unsigned long vm_flags = vma->vm_flags; 7151da177e4SLinus Torvalds pte_t pte = *src_pte; 7161da177e4SLinus Torvalds struct page *page; 7170697212aSChristoph Lameter swp_entry_t entry = pte_to_swp_entry(pte); 7180697212aSChristoph Lameter 7192022b4d1SHugh Dickins if (likely(!non_swap_entry(entry))) { 720570a335bSHugh Dickins if (swap_duplicate(entry) < 0) 721570a335bSHugh Dickins return entry.val; 722570a335bSHugh Dickins 7231da177e4SLinus Torvalds /* make sure dst_mm is on swapoff's mmlist. */ 7241da177e4SLinus Torvalds if (unlikely(list_empty(&dst_mm->mmlist))) { 7251da177e4SLinus Torvalds spin_lock(&mmlist_lock); 726f412ac08SHugh Dickins if (list_empty(&dst_mm->mmlist)) 727f412ac08SHugh Dickins list_add(&dst_mm->mmlist, 728f412ac08SHugh Dickins &src_mm->mmlist); 7291da177e4SLinus Torvalds spin_unlock(&mmlist_lock); 7301da177e4SLinus Torvalds } 731b084d435SKAMEZAWA Hiroyuki rss[MM_SWAPENTS]++; 7322022b4d1SHugh Dickins } else if (is_migration_entry(entry)) { 7339f9f1acdSKonstantin Khlebnikov page = migration_entry_to_page(entry); 7349f9f1acdSKonstantin Khlebnikov 735eca56ff9SJerome Marchand rss[mm_counter(page)]++; 7369f9f1acdSKonstantin Khlebnikov 7379f9f1acdSKonstantin Khlebnikov if (is_write_migration_entry(entry) && 7380697212aSChristoph Lameter is_cow_mapping(vm_flags)) { 7390697212aSChristoph Lameter /* 7409f9f1acdSKonstantin Khlebnikov * COW mappings require pages in both 7419f9f1acdSKonstantin Khlebnikov * parent and child to be set to read. 7420697212aSChristoph Lameter */ 7430697212aSChristoph Lameter make_migration_entry_read(&entry); 7440697212aSChristoph Lameter pte = swp_entry_to_pte(entry); 745c3d16e16SCyrill Gorcunov if (pte_swp_soft_dirty(*src_pte)) 746c3d16e16SCyrill Gorcunov pte = pte_swp_mksoft_dirty(pte); 747f45ec5ffSPeter Xu if (pte_swp_uffd_wp(*src_pte)) 748f45ec5ffSPeter Xu pte = pte_swp_mkuffd_wp(pte); 7490697212aSChristoph Lameter set_pte_at(src_mm, addr, src_pte, pte); 7500697212aSChristoph Lameter } 7515042db43SJérôme Glisse } else if (is_device_private_entry(entry)) { 7525042db43SJérôme Glisse page = device_private_entry_to_page(entry); 7535042db43SJérôme Glisse 7545042db43SJérôme Glisse /* 7555042db43SJérôme Glisse * Update rss count even for unaddressable pages, as 7565042db43SJérôme Glisse * they should treated just like normal pages in this 7575042db43SJérôme Glisse * respect. 7585042db43SJérôme Glisse * 7595042db43SJérôme Glisse * We will likely want to have some new rss counters 7605042db43SJérôme Glisse * for unaddressable pages, at some point. But for now 7615042db43SJérôme Glisse * keep things as they are. 7625042db43SJérôme Glisse */ 7635042db43SJérôme Glisse get_page(page); 7645042db43SJérôme Glisse rss[mm_counter(page)]++; 7655042db43SJérôme Glisse page_dup_rmap(page, false); 7665042db43SJérôme Glisse 7675042db43SJérôme Glisse /* 7685042db43SJérôme Glisse * We do not preserve soft-dirty information, because so 7695042db43SJérôme Glisse * far, checkpoint/restore is the only feature that 7705042db43SJérôme Glisse * requires that. And checkpoint/restore does not work 7715042db43SJérôme Glisse * when a device driver is involved (you cannot easily 7725042db43SJérôme Glisse * save and restore device driver state). 7735042db43SJérôme Glisse */ 7745042db43SJérôme Glisse if (is_write_device_private_entry(entry) && 7755042db43SJérôme Glisse is_cow_mapping(vm_flags)) { 7765042db43SJérôme Glisse make_device_private_entry_read(&entry); 7775042db43SJérôme Glisse pte = swp_entry_to_pte(entry); 778f45ec5ffSPeter Xu if (pte_swp_uffd_wp(*src_pte)) 779f45ec5ffSPeter Xu pte = pte_swp_mkuffd_wp(pte); 7805042db43SJérôme Glisse set_pte_at(src_mm, addr, src_pte, pte); 7815042db43SJérôme Glisse } 7821da177e4SLinus Torvalds } 783df3a57d1SLinus Torvalds set_pte_at(dst_mm, addr, dst_pte, pte); 784df3a57d1SLinus Torvalds return 0; 7851da177e4SLinus Torvalds } 7861da177e4SLinus Torvalds 78770e806e4SPeter Xu /* 78870e806e4SPeter Xu * Copy a present and normal page if necessary. 78970e806e4SPeter Xu * 79070e806e4SPeter Xu * NOTE! The usual case is that this doesn't need to do 79170e806e4SPeter Xu * anything, and can just return a positive value. That 79270e806e4SPeter Xu * will let the caller know that it can just increase 79370e806e4SPeter Xu * the page refcount and re-use the pte the traditional 79470e806e4SPeter Xu * way. 79570e806e4SPeter Xu * 79670e806e4SPeter Xu * But _if_ we need to copy it because it needs to be 79770e806e4SPeter Xu * pinned in the parent (and the child should get its own 79870e806e4SPeter Xu * copy rather than just a reference to the same page), 79970e806e4SPeter Xu * we'll do that here and return zero to let the caller 80070e806e4SPeter Xu * know we're done. 80170e806e4SPeter Xu * 80270e806e4SPeter Xu * And if we need a pre-allocated page but don't yet have 80370e806e4SPeter Xu * one, return a negative error to let the preallocation 80470e806e4SPeter Xu * code know so that it can do so outside the page table 80570e806e4SPeter Xu * lock. 80670e806e4SPeter Xu */ 80770e806e4SPeter Xu static inline int 808c78f4636SPeter Xu copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 809c78f4636SPeter Xu pte_t *dst_pte, pte_t *src_pte, unsigned long addr, int *rss, 810c78f4636SPeter Xu struct page **prealloc, pte_t pte, struct page *page) 81170e806e4SPeter Xu { 81270e806e4SPeter Xu struct page *new_page; 81370e806e4SPeter Xu 81470e806e4SPeter Xu /* 81570e806e4SPeter Xu * What we want to do is to check whether this page may 81670e806e4SPeter Xu * have been pinned by the parent process. If so, 81770e806e4SPeter Xu * instead of wrprotect the pte on both sides, we copy 81870e806e4SPeter Xu * the page immediately so that we'll always guarantee 81970e806e4SPeter Xu * the pinned page won't be randomly replaced in the 82070e806e4SPeter Xu * future. 82170e806e4SPeter Xu * 822f3c64edaSLinus Torvalds * The page pinning checks are just "has this mm ever 823f3c64edaSLinus Torvalds * seen pinning", along with the (inexact) check of 824f3c64edaSLinus Torvalds * the page count. That might give false positives for 825f3c64edaSLinus Torvalds * for pinning, but it will work correctly. 82670e806e4SPeter Xu */ 82797a7e473SPeter Xu if (likely(!page_needs_cow_for_dma(src_vma, page))) 82870e806e4SPeter Xu return 1; 82970e806e4SPeter Xu 83070e806e4SPeter Xu new_page = *prealloc; 83170e806e4SPeter Xu if (!new_page) 83270e806e4SPeter Xu return -EAGAIN; 83370e806e4SPeter Xu 83470e806e4SPeter Xu /* 83570e806e4SPeter Xu * We have a prealloc page, all good! Take it 83670e806e4SPeter Xu * over and copy the page & arm it. 83770e806e4SPeter Xu */ 83870e806e4SPeter Xu *prealloc = NULL; 839c78f4636SPeter Xu copy_user_highpage(new_page, page, addr, src_vma); 84070e806e4SPeter Xu __SetPageUptodate(new_page); 841c78f4636SPeter Xu page_add_new_anon_rmap(new_page, dst_vma, addr, false); 842c78f4636SPeter Xu lru_cache_add_inactive_or_unevictable(new_page, dst_vma); 84370e806e4SPeter Xu rss[mm_counter(new_page)]++; 84470e806e4SPeter Xu 84570e806e4SPeter Xu /* All done, just insert the new page copy in the child */ 846c78f4636SPeter Xu pte = mk_pte(new_page, dst_vma->vm_page_prot); 847c78f4636SPeter Xu pte = maybe_mkwrite(pte_mkdirty(pte), dst_vma); 848c78f4636SPeter Xu set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte); 84970e806e4SPeter Xu return 0; 85070e806e4SPeter Xu } 85170e806e4SPeter Xu 85270e806e4SPeter Xu /* 85370e806e4SPeter Xu * Copy one pte. Returns 0 if succeeded, or -EAGAIN if one preallocated page 85470e806e4SPeter Xu * is required to copy this pte. 85570e806e4SPeter Xu */ 85670e806e4SPeter Xu static inline int 857c78f4636SPeter Xu copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 858c78f4636SPeter Xu pte_t *dst_pte, pte_t *src_pte, unsigned long addr, int *rss, 859c78f4636SPeter Xu struct page **prealloc) 860df3a57d1SLinus Torvalds { 861c78f4636SPeter Xu struct mm_struct *src_mm = src_vma->vm_mm; 862c78f4636SPeter Xu unsigned long vm_flags = src_vma->vm_flags; 863df3a57d1SLinus Torvalds pte_t pte = *src_pte; 864df3a57d1SLinus Torvalds struct page *page; 865df3a57d1SLinus Torvalds 866c78f4636SPeter Xu page = vm_normal_page(src_vma, addr, pte); 86770e806e4SPeter Xu if (page) { 86870e806e4SPeter Xu int retval; 86970e806e4SPeter Xu 870c78f4636SPeter Xu retval = copy_present_page(dst_vma, src_vma, dst_pte, src_pte, 871c78f4636SPeter Xu addr, rss, prealloc, pte, page); 87270e806e4SPeter Xu if (retval <= 0) 87370e806e4SPeter Xu return retval; 87470e806e4SPeter Xu 87570e806e4SPeter Xu get_page(page); 87670e806e4SPeter Xu page_dup_rmap(page, false); 87770e806e4SPeter Xu rss[mm_counter(page)]++; 87870e806e4SPeter Xu } 87970e806e4SPeter Xu 8801da177e4SLinus Torvalds /* 8811da177e4SLinus Torvalds * If it's a COW mapping, write protect it both 8821da177e4SLinus Torvalds * in the parent and the child 8831da177e4SLinus Torvalds */ 8841b2de5d0SLinus Torvalds if (is_cow_mapping(vm_flags) && pte_write(pte)) { 8851da177e4SLinus Torvalds ptep_set_wrprotect(src_mm, addr, src_pte); 8863dc90795SZachary Amsden pte = pte_wrprotect(pte); 8871da177e4SLinus Torvalds } 8881da177e4SLinus Torvalds 8891da177e4SLinus Torvalds /* 8901da177e4SLinus Torvalds * If it's a shared mapping, mark it clean in 8911da177e4SLinus Torvalds * the child 8921da177e4SLinus Torvalds */ 8931da177e4SLinus Torvalds if (vm_flags & VM_SHARED) 8941da177e4SLinus Torvalds pte = pte_mkclean(pte); 8951da177e4SLinus Torvalds pte = pte_mkold(pte); 8966aab341eSLinus Torvalds 897b569a176SPeter Xu /* 898b569a176SPeter Xu * Make sure the _PAGE_UFFD_WP bit is cleared if the new VMA 899b569a176SPeter Xu * does not have the VM_UFFD_WP, which means that the uffd 900b569a176SPeter Xu * fork event is not enabled. 901b569a176SPeter Xu */ 902b569a176SPeter Xu if (!(vm_flags & VM_UFFD_WP)) 903b569a176SPeter Xu pte = pte_clear_uffd_wp(pte); 904b569a176SPeter Xu 905c78f4636SPeter Xu set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte); 90670e806e4SPeter Xu return 0; 9076aab341eSLinus Torvalds } 908ae859762SHugh Dickins 90970e806e4SPeter Xu static inline struct page * 91070e806e4SPeter Xu page_copy_prealloc(struct mm_struct *src_mm, struct vm_area_struct *vma, 91170e806e4SPeter Xu unsigned long addr) 91270e806e4SPeter Xu { 91370e806e4SPeter Xu struct page *new_page; 91470e806e4SPeter Xu 91570e806e4SPeter Xu new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, addr); 91670e806e4SPeter Xu if (!new_page) 91770e806e4SPeter Xu return NULL; 91870e806e4SPeter Xu 91970e806e4SPeter Xu if (mem_cgroup_charge(new_page, src_mm, GFP_KERNEL)) { 92070e806e4SPeter Xu put_page(new_page); 92170e806e4SPeter Xu return NULL; 92270e806e4SPeter Xu } 92370e806e4SPeter Xu cgroup_throttle_swaprate(new_page, GFP_KERNEL); 92470e806e4SPeter Xu 92570e806e4SPeter Xu return new_page; 9261da177e4SLinus Torvalds } 9271da177e4SLinus Torvalds 928c78f4636SPeter Xu static int 929c78f4636SPeter Xu copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 930c78f4636SPeter Xu pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, 931c78f4636SPeter Xu unsigned long end) 9321da177e4SLinus Torvalds { 933c78f4636SPeter Xu struct mm_struct *dst_mm = dst_vma->vm_mm; 934c78f4636SPeter Xu struct mm_struct *src_mm = src_vma->vm_mm; 935c36987e2SDaisuke Nishimura pte_t *orig_src_pte, *orig_dst_pte; 9361da177e4SLinus Torvalds pte_t *src_pte, *dst_pte; 937c74df32cSHugh Dickins spinlock_t *src_ptl, *dst_ptl; 93870e806e4SPeter Xu int progress, ret = 0; 939d559db08SKAMEZAWA Hiroyuki int rss[NR_MM_COUNTERS]; 940570a335bSHugh Dickins swp_entry_t entry = (swp_entry_t){0}; 94170e806e4SPeter Xu struct page *prealloc = NULL; 9421da177e4SLinus Torvalds 9431da177e4SLinus Torvalds again: 94470e806e4SPeter Xu progress = 0; 945d559db08SKAMEZAWA Hiroyuki init_rss_vec(rss); 946d559db08SKAMEZAWA Hiroyuki 947c74df32cSHugh Dickins dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl); 94870e806e4SPeter Xu if (!dst_pte) { 94970e806e4SPeter Xu ret = -ENOMEM; 95070e806e4SPeter Xu goto out; 95170e806e4SPeter Xu } 952ece0e2b6SPeter Zijlstra src_pte = pte_offset_map(src_pmd, addr); 9534c21e2f2SHugh Dickins src_ptl = pte_lockptr(src_mm, src_pmd); 954f20dc5f7SIngo Molnar spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); 955c36987e2SDaisuke Nishimura orig_src_pte = src_pte; 956c36987e2SDaisuke Nishimura orig_dst_pte = dst_pte; 9576606c3e0SZachary Amsden arch_enter_lazy_mmu_mode(); 9581da177e4SLinus Torvalds 9591da177e4SLinus Torvalds do { 9601da177e4SLinus Torvalds /* 9611da177e4SLinus Torvalds * We are holding two locks at this point - either of them 9621da177e4SLinus Torvalds * could generate latencies in another task on another CPU. 9631da177e4SLinus Torvalds */ 964e040f218SHugh Dickins if (progress >= 32) { 965e040f218SHugh Dickins progress = 0; 966e040f218SHugh Dickins if (need_resched() || 96795c354feSNick Piggin spin_needbreak(src_ptl) || spin_needbreak(dst_ptl)) 9681da177e4SLinus Torvalds break; 969e040f218SHugh Dickins } 9701da177e4SLinus Torvalds if (pte_none(*src_pte)) { 9711da177e4SLinus Torvalds progress++; 9721da177e4SLinus Torvalds continue; 9731da177e4SLinus Torvalds } 97479a1971cSLinus Torvalds if (unlikely(!pte_present(*src_pte))) { 97579a1971cSLinus Torvalds entry.val = copy_nonpresent_pte(dst_mm, src_mm, 97679a1971cSLinus Torvalds dst_pte, src_pte, 977c78f4636SPeter Xu src_vma, addr, rss); 978570a335bSHugh Dickins if (entry.val) 979570a335bSHugh Dickins break; 9801da177e4SLinus Torvalds progress += 8; 98179a1971cSLinus Torvalds continue; 98279a1971cSLinus Torvalds } 98370e806e4SPeter Xu /* copy_present_pte() will clear `*prealloc' if consumed */ 984c78f4636SPeter Xu ret = copy_present_pte(dst_vma, src_vma, dst_pte, src_pte, 985c78f4636SPeter Xu addr, rss, &prealloc); 98670e806e4SPeter Xu /* 98770e806e4SPeter Xu * If we need a pre-allocated page for this pte, drop the 98870e806e4SPeter Xu * locks, allocate, and try again. 98970e806e4SPeter Xu */ 99070e806e4SPeter Xu if (unlikely(ret == -EAGAIN)) 99170e806e4SPeter Xu break; 99270e806e4SPeter Xu if (unlikely(prealloc)) { 99370e806e4SPeter Xu /* 99470e806e4SPeter Xu * pre-alloc page cannot be reused by next time so as 99570e806e4SPeter Xu * to strictly follow mempolicy (e.g., alloc_page_vma() 99670e806e4SPeter Xu * will allocate page according to address). This 99770e806e4SPeter Xu * could only happen if one pinned pte changed. 99870e806e4SPeter Xu */ 99970e806e4SPeter Xu put_page(prealloc); 100070e806e4SPeter Xu prealloc = NULL; 100170e806e4SPeter Xu } 100279a1971cSLinus Torvalds progress += 8; 10031da177e4SLinus Torvalds } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); 10041da177e4SLinus Torvalds 10056606c3e0SZachary Amsden arch_leave_lazy_mmu_mode(); 1006c74df32cSHugh Dickins spin_unlock(src_ptl); 1007ece0e2b6SPeter Zijlstra pte_unmap(orig_src_pte); 1008d559db08SKAMEZAWA Hiroyuki add_mm_rss_vec(dst_mm, rss); 1009c36987e2SDaisuke Nishimura pte_unmap_unlock(orig_dst_pte, dst_ptl); 1010c74df32cSHugh Dickins cond_resched(); 1011570a335bSHugh Dickins 1012570a335bSHugh Dickins if (entry.val) { 101370e806e4SPeter Xu if (add_swap_count_continuation(entry, GFP_KERNEL) < 0) { 101470e806e4SPeter Xu ret = -ENOMEM; 101570e806e4SPeter Xu goto out; 101670e806e4SPeter Xu } 101770e806e4SPeter Xu entry.val = 0; 101870e806e4SPeter Xu } else if (ret) { 101970e806e4SPeter Xu WARN_ON_ONCE(ret != -EAGAIN); 1020c78f4636SPeter Xu prealloc = page_copy_prealloc(src_mm, src_vma, addr); 102170e806e4SPeter Xu if (!prealloc) 1022570a335bSHugh Dickins return -ENOMEM; 102370e806e4SPeter Xu /* We've captured and resolved the error. Reset, try again. */ 102470e806e4SPeter Xu ret = 0; 1025570a335bSHugh Dickins } 10261da177e4SLinus Torvalds if (addr != end) 10271da177e4SLinus Torvalds goto again; 102870e806e4SPeter Xu out: 102970e806e4SPeter Xu if (unlikely(prealloc)) 103070e806e4SPeter Xu put_page(prealloc); 103170e806e4SPeter Xu return ret; 10321da177e4SLinus Torvalds } 10331da177e4SLinus Torvalds 1034c78f4636SPeter Xu static inline int 1035c78f4636SPeter Xu copy_pmd_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 1036c78f4636SPeter Xu pud_t *dst_pud, pud_t *src_pud, unsigned long addr, 1037c78f4636SPeter Xu unsigned long end) 10381da177e4SLinus Torvalds { 1039c78f4636SPeter Xu struct mm_struct *dst_mm = dst_vma->vm_mm; 1040c78f4636SPeter Xu struct mm_struct *src_mm = src_vma->vm_mm; 10411da177e4SLinus Torvalds pmd_t *src_pmd, *dst_pmd; 10421da177e4SLinus Torvalds unsigned long next; 10431da177e4SLinus Torvalds 10441da177e4SLinus Torvalds dst_pmd = pmd_alloc(dst_mm, dst_pud, addr); 10451da177e4SLinus Torvalds if (!dst_pmd) 10461da177e4SLinus Torvalds return -ENOMEM; 10471da177e4SLinus Torvalds src_pmd = pmd_offset(src_pud, addr); 10481da177e4SLinus Torvalds do { 10491da177e4SLinus Torvalds next = pmd_addr_end(addr, end); 105084c3fc4eSZi Yan if (is_swap_pmd(*src_pmd) || pmd_trans_huge(*src_pmd) 105184c3fc4eSZi Yan || pmd_devmap(*src_pmd)) { 105271e3aac0SAndrea Arcangeli int err; 1053c78f4636SPeter Xu VM_BUG_ON_VMA(next-addr != HPAGE_PMD_SIZE, src_vma); 105471e3aac0SAndrea Arcangeli err = copy_huge_pmd(dst_mm, src_mm, 1055c78f4636SPeter Xu dst_pmd, src_pmd, addr, src_vma); 105671e3aac0SAndrea Arcangeli if (err == -ENOMEM) 105771e3aac0SAndrea Arcangeli return -ENOMEM; 105871e3aac0SAndrea Arcangeli if (!err) 105971e3aac0SAndrea Arcangeli continue; 106071e3aac0SAndrea Arcangeli /* fall through */ 106171e3aac0SAndrea Arcangeli } 10621da177e4SLinus Torvalds if (pmd_none_or_clear_bad(src_pmd)) 10631da177e4SLinus Torvalds continue; 1064c78f4636SPeter Xu if (copy_pte_range(dst_vma, src_vma, dst_pmd, src_pmd, 1065c78f4636SPeter Xu addr, next)) 10661da177e4SLinus Torvalds return -ENOMEM; 10671da177e4SLinus Torvalds } while (dst_pmd++, src_pmd++, addr = next, addr != end); 10681da177e4SLinus Torvalds return 0; 10691da177e4SLinus Torvalds } 10701da177e4SLinus Torvalds 1071c78f4636SPeter Xu static inline int 1072c78f4636SPeter Xu copy_pud_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 1073c78f4636SPeter Xu p4d_t *dst_p4d, p4d_t *src_p4d, unsigned long addr, 1074c78f4636SPeter Xu unsigned long end) 10751da177e4SLinus Torvalds { 1076c78f4636SPeter Xu struct mm_struct *dst_mm = dst_vma->vm_mm; 1077c78f4636SPeter Xu struct mm_struct *src_mm = src_vma->vm_mm; 10781da177e4SLinus Torvalds pud_t *src_pud, *dst_pud; 10791da177e4SLinus Torvalds unsigned long next; 10801da177e4SLinus Torvalds 1081c2febafcSKirill A. Shutemov dst_pud = pud_alloc(dst_mm, dst_p4d, addr); 10821da177e4SLinus Torvalds if (!dst_pud) 10831da177e4SLinus Torvalds return -ENOMEM; 1084c2febafcSKirill A. Shutemov src_pud = pud_offset(src_p4d, addr); 10851da177e4SLinus Torvalds do { 10861da177e4SLinus Torvalds next = pud_addr_end(addr, end); 1087a00cc7d9SMatthew Wilcox if (pud_trans_huge(*src_pud) || pud_devmap(*src_pud)) { 1088a00cc7d9SMatthew Wilcox int err; 1089a00cc7d9SMatthew Wilcox 1090c78f4636SPeter Xu VM_BUG_ON_VMA(next-addr != HPAGE_PUD_SIZE, src_vma); 1091a00cc7d9SMatthew Wilcox err = copy_huge_pud(dst_mm, src_mm, 1092c78f4636SPeter Xu dst_pud, src_pud, addr, src_vma); 1093a00cc7d9SMatthew Wilcox if (err == -ENOMEM) 1094a00cc7d9SMatthew Wilcox return -ENOMEM; 1095a00cc7d9SMatthew Wilcox if (!err) 1096a00cc7d9SMatthew Wilcox continue; 1097a00cc7d9SMatthew Wilcox /* fall through */ 1098a00cc7d9SMatthew Wilcox } 10991da177e4SLinus Torvalds if (pud_none_or_clear_bad(src_pud)) 11001da177e4SLinus Torvalds continue; 1101c78f4636SPeter Xu if (copy_pmd_range(dst_vma, src_vma, dst_pud, src_pud, 1102c78f4636SPeter Xu addr, next)) 11031da177e4SLinus Torvalds return -ENOMEM; 11041da177e4SLinus Torvalds } while (dst_pud++, src_pud++, addr = next, addr != end); 11051da177e4SLinus Torvalds return 0; 11061da177e4SLinus Torvalds } 11071da177e4SLinus Torvalds 1108c78f4636SPeter Xu static inline int 1109c78f4636SPeter Xu copy_p4d_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, 1110c78f4636SPeter Xu pgd_t *dst_pgd, pgd_t *src_pgd, unsigned long addr, 1111c78f4636SPeter Xu unsigned long end) 1112c2febafcSKirill A. Shutemov { 1113c78f4636SPeter Xu struct mm_struct *dst_mm = dst_vma->vm_mm; 1114c2febafcSKirill A. Shutemov p4d_t *src_p4d, *dst_p4d; 1115c2febafcSKirill A. Shutemov unsigned long next; 1116c2febafcSKirill A. Shutemov 1117c2febafcSKirill A. Shutemov dst_p4d = p4d_alloc(dst_mm, dst_pgd, addr); 1118c2febafcSKirill A. Shutemov if (!dst_p4d) 1119c2febafcSKirill A. Shutemov return -ENOMEM; 1120c2febafcSKirill A. Shutemov src_p4d = p4d_offset(src_pgd, addr); 1121c2febafcSKirill A. Shutemov do { 1122c2febafcSKirill A. Shutemov next = p4d_addr_end(addr, end); 1123c2febafcSKirill A. Shutemov if (p4d_none_or_clear_bad(src_p4d)) 1124c2febafcSKirill A. Shutemov continue; 1125c78f4636SPeter Xu if (copy_pud_range(dst_vma, src_vma, dst_p4d, src_p4d, 1126c78f4636SPeter Xu addr, next)) 1127c2febafcSKirill A. Shutemov return -ENOMEM; 1128c2febafcSKirill A. Shutemov } while (dst_p4d++, src_p4d++, addr = next, addr != end); 1129c2febafcSKirill A. Shutemov return 0; 1130c2febafcSKirill A. Shutemov } 1131c2febafcSKirill A. Shutemov 1132c78f4636SPeter Xu int 1133c78f4636SPeter Xu copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) 11341da177e4SLinus Torvalds { 11351da177e4SLinus Torvalds pgd_t *src_pgd, *dst_pgd; 11361da177e4SLinus Torvalds unsigned long next; 1137c78f4636SPeter Xu unsigned long addr = src_vma->vm_start; 1138c78f4636SPeter Xu unsigned long end = src_vma->vm_end; 1139c78f4636SPeter Xu struct mm_struct *dst_mm = dst_vma->vm_mm; 1140c78f4636SPeter Xu struct mm_struct *src_mm = src_vma->vm_mm; 1141ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 11422ec74c3eSSagi Grimberg bool is_cow; 1143cddb8a5cSAndrea Arcangeli int ret; 11441da177e4SLinus Torvalds 1145d992895bSNick Piggin /* 1146d992895bSNick Piggin * Don't copy ptes where a page fault will fill them correctly. 1147d992895bSNick Piggin * Fork becomes much lighter when there are big shared or private 1148d992895bSNick Piggin * readonly mappings. The tradeoff is that copy_page_range is more 1149d992895bSNick Piggin * efficient than faulting. 1150d992895bSNick Piggin */ 1151c78f4636SPeter Xu if (!(src_vma->vm_flags & (VM_HUGETLB | VM_PFNMAP | VM_MIXEDMAP)) && 1152c78f4636SPeter Xu !src_vma->anon_vma) 1153d992895bSNick Piggin return 0; 1154d992895bSNick Piggin 1155c78f4636SPeter Xu if (is_vm_hugetlb_page(src_vma)) 1156c78f4636SPeter Xu return copy_hugetlb_page_range(dst_mm, src_mm, src_vma); 11571da177e4SLinus Torvalds 1158c78f4636SPeter Xu if (unlikely(src_vma->vm_flags & VM_PFNMAP)) { 11592ab64037Svenkatesh.pallipadi@intel.com /* 11602ab64037Svenkatesh.pallipadi@intel.com * We do not free on error cases below as remove_vma 11612ab64037Svenkatesh.pallipadi@intel.com * gets called on error from higher level routine 11622ab64037Svenkatesh.pallipadi@intel.com */ 1163c78f4636SPeter Xu ret = track_pfn_copy(src_vma); 11642ab64037Svenkatesh.pallipadi@intel.com if (ret) 11652ab64037Svenkatesh.pallipadi@intel.com return ret; 11662ab64037Svenkatesh.pallipadi@intel.com } 11672ab64037Svenkatesh.pallipadi@intel.com 1168cddb8a5cSAndrea Arcangeli /* 1169cddb8a5cSAndrea Arcangeli * We need to invalidate the secondary MMU mappings only when 1170cddb8a5cSAndrea Arcangeli * there could be a permission downgrade on the ptes of the 1171cddb8a5cSAndrea Arcangeli * parent mm. And a permission downgrade will only happen if 1172cddb8a5cSAndrea Arcangeli * is_cow_mapping() returns true. 1173cddb8a5cSAndrea Arcangeli */ 1174c78f4636SPeter Xu is_cow = is_cow_mapping(src_vma->vm_flags); 1175ac46d4f3SJérôme Glisse 1176ac46d4f3SJérôme Glisse if (is_cow) { 11777269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_PAGE, 1178c78f4636SPeter Xu 0, src_vma, src_mm, addr, end); 1179ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 118057efa1feSJason Gunthorpe /* 118157efa1feSJason Gunthorpe * Disabling preemption is not needed for the write side, as 118257efa1feSJason Gunthorpe * the read side doesn't spin, but goes to the mmap_lock. 118357efa1feSJason Gunthorpe * 118457efa1feSJason Gunthorpe * Use the raw variant of the seqcount_t write API to avoid 118557efa1feSJason Gunthorpe * lockdep complaining about preemptibility. 118657efa1feSJason Gunthorpe */ 118757efa1feSJason Gunthorpe mmap_assert_write_locked(src_mm); 118857efa1feSJason Gunthorpe raw_write_seqcount_begin(&src_mm->write_protect_seq); 1189ac46d4f3SJérôme Glisse } 1190cddb8a5cSAndrea Arcangeli 1191cddb8a5cSAndrea Arcangeli ret = 0; 11921da177e4SLinus Torvalds dst_pgd = pgd_offset(dst_mm, addr); 11931da177e4SLinus Torvalds src_pgd = pgd_offset(src_mm, addr); 11941da177e4SLinus Torvalds do { 11951da177e4SLinus Torvalds next = pgd_addr_end(addr, end); 11961da177e4SLinus Torvalds if (pgd_none_or_clear_bad(src_pgd)) 11971da177e4SLinus Torvalds continue; 1198c78f4636SPeter Xu if (unlikely(copy_p4d_range(dst_vma, src_vma, dst_pgd, src_pgd, 1199c78f4636SPeter Xu addr, next))) { 1200cddb8a5cSAndrea Arcangeli ret = -ENOMEM; 1201cddb8a5cSAndrea Arcangeli break; 1202cddb8a5cSAndrea Arcangeli } 12031da177e4SLinus Torvalds } while (dst_pgd++, src_pgd++, addr = next, addr != end); 1204cddb8a5cSAndrea Arcangeli 120557efa1feSJason Gunthorpe if (is_cow) { 120657efa1feSJason Gunthorpe raw_write_seqcount_end(&src_mm->write_protect_seq); 1207ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 120857efa1feSJason Gunthorpe } 1209cddb8a5cSAndrea Arcangeli return ret; 12101da177e4SLinus Torvalds } 12111da177e4SLinus Torvalds 121251c6f666SRobin Holt static unsigned long zap_pte_range(struct mmu_gather *tlb, 1213b5810039SNick Piggin struct vm_area_struct *vma, pmd_t *pmd, 12141da177e4SLinus Torvalds unsigned long addr, unsigned long end, 121597a89413SPeter Zijlstra struct zap_details *details) 12161da177e4SLinus Torvalds { 1217b5810039SNick Piggin struct mm_struct *mm = tlb->mm; 1218d16dfc55SPeter Zijlstra int force_flush = 0; 1219d559db08SKAMEZAWA Hiroyuki int rss[NR_MM_COUNTERS]; 122097a89413SPeter Zijlstra spinlock_t *ptl; 12215f1a1907SSteven Rostedt pte_t *start_pte; 122297a89413SPeter Zijlstra pte_t *pte; 12238a5f14a2SKirill A. Shutemov swp_entry_t entry; 1224d559db08SKAMEZAWA Hiroyuki 1225ed6a7935SPeter Zijlstra tlb_change_page_size(tlb, PAGE_SIZE); 1226d16dfc55SPeter Zijlstra again: 1227e303297eSPeter Zijlstra init_rss_vec(rss); 12285f1a1907SSteven Rostedt start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 12295f1a1907SSteven Rostedt pte = start_pte; 12303ea27719SMel Gorman flush_tlb_batched_pending(mm); 12316606c3e0SZachary Amsden arch_enter_lazy_mmu_mode(); 12321da177e4SLinus Torvalds do { 12331da177e4SLinus Torvalds pte_t ptent = *pte; 1234166f61b9STobin C Harding if (pte_none(ptent)) 12351da177e4SLinus Torvalds continue; 123651c6f666SRobin Holt 12377b167b68SMinchan Kim if (need_resched()) 12387b167b68SMinchan Kim break; 12397b167b68SMinchan Kim 12406f5e6b9eSHugh Dickins if (pte_present(ptent)) { 12416f5e6b9eSHugh Dickins struct page *page; 12426f5e6b9eSHugh Dickins 124325b2995aSChristoph Hellwig page = vm_normal_page(vma, addr, ptent); 12441da177e4SLinus Torvalds if (unlikely(details) && page) { 12451da177e4SLinus Torvalds /* 12461da177e4SLinus Torvalds * unmap_shared_mapping_pages() wants to 12471da177e4SLinus Torvalds * invalidate cache without truncating: 12481da177e4SLinus Torvalds * unmap shared but keep private pages. 12491da177e4SLinus Torvalds */ 12501da177e4SLinus Torvalds if (details->check_mapping && 1251800d8c63SKirill A. Shutemov details->check_mapping != page_rmapping(page)) 12521da177e4SLinus Torvalds continue; 12531da177e4SLinus Torvalds } 1254b5810039SNick Piggin ptent = ptep_get_and_clear_full(mm, addr, pte, 1255a600388dSZachary Amsden tlb->fullmm); 12561da177e4SLinus Torvalds tlb_remove_tlb_entry(tlb, pte, addr); 12571da177e4SLinus Torvalds if (unlikely(!page)) 12581da177e4SLinus Torvalds continue; 1259eca56ff9SJerome Marchand 1260eca56ff9SJerome Marchand if (!PageAnon(page)) { 12611cf35d47SLinus Torvalds if (pte_dirty(ptent)) { 12621cf35d47SLinus Torvalds force_flush = 1; 12636237bcd9SHugh Dickins set_page_dirty(page); 12641cf35d47SLinus Torvalds } 12654917e5d0SJohannes Weiner if (pte_young(ptent) && 126664363aadSJoe Perches likely(!(vma->vm_flags & VM_SEQ_READ))) 1267bf3f3bc5SNick Piggin mark_page_accessed(page); 12686237bcd9SHugh Dickins } 1269eca56ff9SJerome Marchand rss[mm_counter(page)]--; 1270d281ee61SKirill A. Shutemov page_remove_rmap(page, false); 12713dc14741SHugh Dickins if (unlikely(page_mapcount(page) < 0)) 12723dc14741SHugh Dickins print_bad_pte(vma, addr, ptent, page); 1273e9d55e15SAneesh Kumar K.V if (unlikely(__tlb_remove_page(tlb, page))) { 12741cf35d47SLinus Torvalds force_flush = 1; 1275ce9ec37bSWill Deacon addr += PAGE_SIZE; 1276d16dfc55SPeter Zijlstra break; 12771cf35d47SLinus Torvalds } 12781da177e4SLinus Torvalds continue; 12791da177e4SLinus Torvalds } 12805042db43SJérôme Glisse 12815042db43SJérôme Glisse entry = pte_to_swp_entry(ptent); 1282463b7a17SRalph Campbell if (is_device_private_entry(entry)) { 12835042db43SJérôme Glisse struct page *page = device_private_entry_to_page(entry); 12845042db43SJérôme Glisse 12855042db43SJérôme Glisse if (unlikely(details && details->check_mapping)) { 12865042db43SJérôme Glisse /* 12875042db43SJérôme Glisse * unmap_shared_mapping_pages() wants to 12885042db43SJérôme Glisse * invalidate cache without truncating: 12895042db43SJérôme Glisse * unmap shared but keep private pages. 12905042db43SJérôme Glisse */ 12915042db43SJérôme Glisse if (details->check_mapping != 12925042db43SJérôme Glisse page_rmapping(page)) 12935042db43SJérôme Glisse continue; 12945042db43SJérôme Glisse } 12955042db43SJérôme Glisse 12965042db43SJérôme Glisse pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); 12975042db43SJérôme Glisse rss[mm_counter(page)]--; 12985042db43SJérôme Glisse page_remove_rmap(page, false); 12995042db43SJérôme Glisse put_page(page); 13005042db43SJérôme Glisse continue; 13015042db43SJérôme Glisse } 13025042db43SJérôme Glisse 13033e8715fdSKirill A. Shutemov /* If details->check_mapping, we leave swap entries. */ 13043e8715fdSKirill A. Shutemov if (unlikely(details)) 13051da177e4SLinus Torvalds continue; 1306b084d435SKAMEZAWA Hiroyuki 1307b084d435SKAMEZAWA Hiroyuki if (!non_swap_entry(entry)) 1308b084d435SKAMEZAWA Hiroyuki rss[MM_SWAPENTS]--; 13099f9f1acdSKonstantin Khlebnikov else if (is_migration_entry(entry)) { 13109f9f1acdSKonstantin Khlebnikov struct page *page; 13119f9f1acdSKonstantin Khlebnikov 13129f9f1acdSKonstantin Khlebnikov page = migration_entry_to_page(entry); 1313eca56ff9SJerome Marchand rss[mm_counter(page)]--; 13149f9f1acdSKonstantin Khlebnikov } 1315b084d435SKAMEZAWA Hiroyuki if (unlikely(!free_swap_and_cache(entry))) 13162509ef26SHugh Dickins print_bad_pte(vma, addr, ptent, NULL); 13179888a1caSZachary Amsden pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); 131897a89413SPeter Zijlstra } while (pte++, addr += PAGE_SIZE, addr != end); 1319ae859762SHugh Dickins 1320d559db08SKAMEZAWA Hiroyuki add_mm_rss_vec(mm, rss); 13216606c3e0SZachary Amsden arch_leave_lazy_mmu_mode(); 132251c6f666SRobin Holt 13231cf35d47SLinus Torvalds /* Do the actual TLB flush before dropping ptl */ 1324fb7332a9SWill Deacon if (force_flush) 13251cf35d47SLinus Torvalds tlb_flush_mmu_tlbonly(tlb); 13261cf35d47SLinus Torvalds pte_unmap_unlock(start_pte, ptl); 13271cf35d47SLinus Torvalds 13281cf35d47SLinus Torvalds /* 13291cf35d47SLinus Torvalds * If we forced a TLB flush (either due to running out of 13301cf35d47SLinus Torvalds * batch buffers or because we needed to flush dirty TLB 13311cf35d47SLinus Torvalds * entries before releasing the ptl), free the batched 13321cf35d47SLinus Torvalds * memory too. Restart if we didn't do everything. 13331cf35d47SLinus Torvalds */ 13341cf35d47SLinus Torvalds if (force_flush) { 13351cf35d47SLinus Torvalds force_flush = 0; 1336fa0aafb8SPeter Zijlstra tlb_flush_mmu(tlb); 13377b167b68SMinchan Kim } 13387b167b68SMinchan Kim 13397b167b68SMinchan Kim if (addr != end) { 13407b167b68SMinchan Kim cond_resched(); 1341d16dfc55SPeter Zijlstra goto again; 1342d16dfc55SPeter Zijlstra } 1343d16dfc55SPeter Zijlstra 134451c6f666SRobin Holt return addr; 13451da177e4SLinus Torvalds } 13461da177e4SLinus Torvalds 134751c6f666SRobin Holt static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, 1348b5810039SNick Piggin struct vm_area_struct *vma, pud_t *pud, 13491da177e4SLinus Torvalds unsigned long addr, unsigned long end, 135097a89413SPeter Zijlstra struct zap_details *details) 13511da177e4SLinus Torvalds { 13521da177e4SLinus Torvalds pmd_t *pmd; 13531da177e4SLinus Torvalds unsigned long next; 13541da177e4SLinus Torvalds 13551da177e4SLinus Torvalds pmd = pmd_offset(pud, addr); 13561da177e4SLinus Torvalds do { 13571da177e4SLinus Torvalds next = pmd_addr_end(addr, end); 135884c3fc4eSZi Yan if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) { 135953406ed1SHugh Dickins if (next - addr != HPAGE_PMD_SIZE) 1360fd60775aSDavid Rientjes __split_huge_pmd(vma, pmd, addr, false, NULL); 136153406ed1SHugh Dickins else if (zap_huge_pmd(tlb, vma, pmd, addr)) 13621a5a9906SAndrea Arcangeli goto next; 136371e3aac0SAndrea Arcangeli /* fall through */ 136422061a1fSHugh Dickins } else if (details && details->single_page && 136522061a1fSHugh Dickins PageTransCompound(details->single_page) && 136622061a1fSHugh Dickins next - addr == HPAGE_PMD_SIZE && pmd_none(*pmd)) { 136722061a1fSHugh Dickins spinlock_t *ptl = pmd_lock(tlb->mm, pmd); 136822061a1fSHugh Dickins /* 136922061a1fSHugh Dickins * Take and drop THP pmd lock so that we cannot return 137022061a1fSHugh Dickins * prematurely, while zap_huge_pmd() has cleared *pmd, 137122061a1fSHugh Dickins * but not yet decremented compound_mapcount(). 137222061a1fSHugh Dickins */ 137322061a1fSHugh Dickins spin_unlock(ptl); 137471e3aac0SAndrea Arcangeli } 137522061a1fSHugh Dickins 13761a5a9906SAndrea Arcangeli /* 13771a5a9906SAndrea Arcangeli * Here there can be other concurrent MADV_DONTNEED or 13781a5a9906SAndrea Arcangeli * trans huge page faults running, and if the pmd is 13791a5a9906SAndrea Arcangeli * none or trans huge it can change under us. This is 1380c1e8d7c6SMichel Lespinasse * because MADV_DONTNEED holds the mmap_lock in read 13811a5a9906SAndrea Arcangeli * mode. 13821a5a9906SAndrea Arcangeli */ 13831a5a9906SAndrea Arcangeli if (pmd_none_or_trans_huge_or_clear_bad(pmd)) 13841a5a9906SAndrea Arcangeli goto next; 138597a89413SPeter Zijlstra next = zap_pte_range(tlb, vma, pmd, addr, next, details); 13861a5a9906SAndrea Arcangeli next: 138797a89413SPeter Zijlstra cond_resched(); 138897a89413SPeter Zijlstra } while (pmd++, addr = next, addr != end); 138951c6f666SRobin Holt 139051c6f666SRobin Holt return addr; 13911da177e4SLinus Torvalds } 13921da177e4SLinus Torvalds 139351c6f666SRobin Holt static inline unsigned long zap_pud_range(struct mmu_gather *tlb, 1394c2febafcSKirill A. Shutemov struct vm_area_struct *vma, p4d_t *p4d, 13951da177e4SLinus Torvalds unsigned long addr, unsigned long end, 139697a89413SPeter Zijlstra struct zap_details *details) 13971da177e4SLinus Torvalds { 13981da177e4SLinus Torvalds pud_t *pud; 13991da177e4SLinus Torvalds unsigned long next; 14001da177e4SLinus Torvalds 1401c2febafcSKirill A. Shutemov pud = pud_offset(p4d, addr); 14021da177e4SLinus Torvalds do { 14031da177e4SLinus Torvalds next = pud_addr_end(addr, end); 1404a00cc7d9SMatthew Wilcox if (pud_trans_huge(*pud) || pud_devmap(*pud)) { 1405a00cc7d9SMatthew Wilcox if (next - addr != HPAGE_PUD_SIZE) { 140642fc5414SMichel Lespinasse mmap_assert_locked(tlb->mm); 1407a00cc7d9SMatthew Wilcox split_huge_pud(vma, pud, addr); 1408a00cc7d9SMatthew Wilcox } else if (zap_huge_pud(tlb, vma, pud, addr)) 1409a00cc7d9SMatthew Wilcox goto next; 1410a00cc7d9SMatthew Wilcox /* fall through */ 1411a00cc7d9SMatthew Wilcox } 141297a89413SPeter Zijlstra if (pud_none_or_clear_bad(pud)) 14131da177e4SLinus Torvalds continue; 141497a89413SPeter Zijlstra next = zap_pmd_range(tlb, vma, pud, addr, next, details); 1415a00cc7d9SMatthew Wilcox next: 1416a00cc7d9SMatthew Wilcox cond_resched(); 141797a89413SPeter Zijlstra } while (pud++, addr = next, addr != end); 141851c6f666SRobin Holt 141951c6f666SRobin Holt return addr; 14201da177e4SLinus Torvalds } 14211da177e4SLinus Torvalds 1422c2febafcSKirill A. Shutemov static inline unsigned long zap_p4d_range(struct mmu_gather *tlb, 1423c2febafcSKirill A. Shutemov struct vm_area_struct *vma, pgd_t *pgd, 1424c2febafcSKirill A. Shutemov unsigned long addr, unsigned long end, 1425c2febafcSKirill A. Shutemov struct zap_details *details) 1426c2febafcSKirill A. Shutemov { 1427c2febafcSKirill A. Shutemov p4d_t *p4d; 1428c2febafcSKirill A. Shutemov unsigned long next; 1429c2febafcSKirill A. Shutemov 1430c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, addr); 1431c2febafcSKirill A. Shutemov do { 1432c2febafcSKirill A. Shutemov next = p4d_addr_end(addr, end); 1433c2febafcSKirill A. Shutemov if (p4d_none_or_clear_bad(p4d)) 1434c2febafcSKirill A. Shutemov continue; 1435c2febafcSKirill A. Shutemov next = zap_pud_range(tlb, vma, p4d, addr, next, details); 1436c2febafcSKirill A. Shutemov } while (p4d++, addr = next, addr != end); 1437c2febafcSKirill A. Shutemov 1438c2febafcSKirill A. Shutemov return addr; 1439c2febafcSKirill A. Shutemov } 1440c2febafcSKirill A. Shutemov 1441aac45363SMichal Hocko void unmap_page_range(struct mmu_gather *tlb, 144251c6f666SRobin Holt struct vm_area_struct *vma, 14431da177e4SLinus Torvalds unsigned long addr, unsigned long end, 144497a89413SPeter Zijlstra struct zap_details *details) 14451da177e4SLinus Torvalds { 14461da177e4SLinus Torvalds pgd_t *pgd; 14471da177e4SLinus Torvalds unsigned long next; 14481da177e4SLinus Torvalds 14491da177e4SLinus Torvalds BUG_ON(addr >= end); 14501da177e4SLinus Torvalds tlb_start_vma(tlb, vma); 14511da177e4SLinus Torvalds pgd = pgd_offset(vma->vm_mm, addr); 14521da177e4SLinus Torvalds do { 14531da177e4SLinus Torvalds next = pgd_addr_end(addr, end); 145497a89413SPeter Zijlstra if (pgd_none_or_clear_bad(pgd)) 14551da177e4SLinus Torvalds continue; 1456c2febafcSKirill A. Shutemov next = zap_p4d_range(tlb, vma, pgd, addr, next, details); 145797a89413SPeter Zijlstra } while (pgd++, addr = next, addr != end); 14581da177e4SLinus Torvalds tlb_end_vma(tlb, vma); 14591da177e4SLinus Torvalds } 14601da177e4SLinus Torvalds 1461f5cc4eefSAl Viro 1462f5cc4eefSAl Viro static void unmap_single_vma(struct mmu_gather *tlb, 14631da177e4SLinus Torvalds struct vm_area_struct *vma, unsigned long start_addr, 14644f74d2c8SLinus Torvalds unsigned long end_addr, 14651da177e4SLinus Torvalds struct zap_details *details) 14661da177e4SLinus Torvalds { 1467f5cc4eefSAl Viro unsigned long start = max(vma->vm_start, start_addr); 14681da177e4SLinus Torvalds unsigned long end; 14691da177e4SLinus Torvalds 14701da177e4SLinus Torvalds if (start >= vma->vm_end) 1471f5cc4eefSAl Viro return; 14721da177e4SLinus Torvalds end = min(vma->vm_end, end_addr); 14731da177e4SLinus Torvalds if (end <= vma->vm_start) 1474f5cc4eefSAl Viro return; 14751da177e4SLinus Torvalds 1476cbc91f71SSrikar Dronamraju if (vma->vm_file) 1477cbc91f71SSrikar Dronamraju uprobe_munmap(vma, start, end); 1478cbc91f71SSrikar Dronamraju 1479b3b9c293SKonstantin Khlebnikov if (unlikely(vma->vm_flags & VM_PFNMAP)) 14805180da41SSuresh Siddha untrack_pfn(vma, 0, 0); 14812ab64037Svenkatesh.pallipadi@intel.com 14828b2a1238SAl Viro if (start != end) { 148351c6f666SRobin Holt if (unlikely(is_vm_hugetlb_page(vma))) { 1484a137e1ccSAndi Kleen /* 1485a137e1ccSAndi Kleen * It is undesirable to test vma->vm_file as it 1486a137e1ccSAndi Kleen * should be non-null for valid hugetlb area. 1487a137e1ccSAndi Kleen * However, vm_file will be NULL in the error 14887aa6b4adSDavidlohr Bueso * cleanup path of mmap_region. When 1489a137e1ccSAndi Kleen * hugetlbfs ->mmap method fails, 14907aa6b4adSDavidlohr Bueso * mmap_region() nullifies vma->vm_file 1491a137e1ccSAndi Kleen * before calling this function to clean up. 1492a137e1ccSAndi Kleen * Since no pte has actually been setup, it is 1493a137e1ccSAndi Kleen * safe to do nothing in this case. 1494a137e1ccSAndi Kleen */ 149524669e58SAneesh Kumar K.V if (vma->vm_file) { 149683cde9e8SDavidlohr Bueso i_mmap_lock_write(vma->vm_file->f_mapping); 1497d833352aSMel Gorman __unmap_hugepage_range_final(tlb, vma, start, end, NULL); 149883cde9e8SDavidlohr Bueso i_mmap_unlock_write(vma->vm_file->f_mapping); 149924669e58SAneesh Kumar K.V } 150051c6f666SRobin Holt } else 1501038c7aa1SAl Viro unmap_page_range(tlb, vma, start, end, details); 150297a89413SPeter Zijlstra } 150351c6f666SRobin Holt } 15041da177e4SLinus Torvalds 1505f5cc4eefSAl Viro /** 1506f5cc4eefSAl Viro * unmap_vmas - unmap a range of memory covered by a list of vma's 1507f5cc4eefSAl Viro * @tlb: address of the caller's struct mmu_gather 1508f5cc4eefSAl Viro * @vma: the starting vma 1509f5cc4eefSAl Viro * @start_addr: virtual address at which to start unmapping 1510f5cc4eefSAl Viro * @end_addr: virtual address at which to end unmapping 1511f5cc4eefSAl Viro * 1512f5cc4eefSAl Viro * Unmap all pages in the vma list. 1513f5cc4eefSAl Viro * 1514f5cc4eefSAl Viro * Only addresses between `start' and `end' will be unmapped. 1515f5cc4eefSAl Viro * 1516f5cc4eefSAl Viro * The VMA list must be sorted in ascending virtual address order. 1517f5cc4eefSAl Viro * 1518f5cc4eefSAl Viro * unmap_vmas() assumes that the caller will flush the whole unmapped address 1519f5cc4eefSAl Viro * range after unmap_vmas() returns. So the only responsibility here is to 1520f5cc4eefSAl Viro * ensure that any thus-far unmapped pages are flushed before unmap_vmas() 1521f5cc4eefSAl Viro * drops the lock and schedules. 1522f5cc4eefSAl Viro */ 1523f5cc4eefSAl Viro void unmap_vmas(struct mmu_gather *tlb, 1524f5cc4eefSAl Viro struct vm_area_struct *vma, unsigned long start_addr, 15254f74d2c8SLinus Torvalds unsigned long end_addr) 1526f5cc4eefSAl Viro { 1527ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 1528f5cc4eefSAl Viro 15296f4f13e8SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, vma->vm_mm, 15306f4f13e8SJérôme Glisse start_addr, end_addr); 1531ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 1532f5cc4eefSAl Viro for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) 15334f74d2c8SLinus Torvalds unmap_single_vma(tlb, vma, start_addr, end_addr, NULL); 1534ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 15351da177e4SLinus Torvalds } 15361da177e4SLinus Torvalds 15371da177e4SLinus Torvalds /** 15381da177e4SLinus Torvalds * zap_page_range - remove user pages in a given range 15391da177e4SLinus Torvalds * @vma: vm_area_struct holding the applicable pages 1540eb4546bbSRandy Dunlap * @start: starting address of pages to zap 15411da177e4SLinus Torvalds * @size: number of bytes to zap 1542f5cc4eefSAl Viro * 1543f5cc4eefSAl Viro * Caller must protect the VMA list 15441da177e4SLinus Torvalds */ 15457e027b14SLinus Torvalds void zap_page_range(struct vm_area_struct *vma, unsigned long start, 1546ecf1385dSKirill A. Shutemov unsigned long size) 15471da177e4SLinus Torvalds { 1548ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 1549d16dfc55SPeter Zijlstra struct mmu_gather tlb; 15501da177e4SLinus Torvalds 15511da177e4SLinus Torvalds lru_add_drain(); 15527269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, 15536f4f13e8SJérôme Glisse start, start + size); 1554a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 1555ac46d4f3SJérôme Glisse update_hiwater_rss(vma->vm_mm); 1556ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 1557ac46d4f3SJérôme Glisse for ( ; vma && vma->vm_start < range.end; vma = vma->vm_next) 1558ac46d4f3SJérôme Glisse unmap_single_vma(&tlb, vma, start, range.end, NULL); 1559ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 1560ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 15611da177e4SLinus Torvalds } 15621da177e4SLinus Torvalds 1563c627f9ccSJack Steiner /** 1564f5cc4eefSAl Viro * zap_page_range_single - remove user pages in a given range 1565f5cc4eefSAl Viro * @vma: vm_area_struct holding the applicable pages 1566f5cc4eefSAl Viro * @address: starting address of pages to zap 1567f5cc4eefSAl Viro * @size: number of bytes to zap 15688a5f14a2SKirill A. Shutemov * @details: details of shared cache invalidation 1569f5cc4eefSAl Viro * 1570f5cc4eefSAl Viro * The range must fit into one VMA. 1571f5cc4eefSAl Viro */ 1572f5cc4eefSAl Viro static void zap_page_range_single(struct vm_area_struct *vma, unsigned long address, 1573f5cc4eefSAl Viro unsigned long size, struct zap_details *details) 1574f5cc4eefSAl Viro { 1575ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 1576f5cc4eefSAl Viro struct mmu_gather tlb; 1577f5cc4eefSAl Viro 1578f5cc4eefSAl Viro lru_add_drain(); 15797269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm, 15806f4f13e8SJérôme Glisse address, address + size); 1581a72afd87SWill Deacon tlb_gather_mmu(&tlb, vma->vm_mm); 1582ac46d4f3SJérôme Glisse update_hiwater_rss(vma->vm_mm); 1583ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 1584ac46d4f3SJérôme Glisse unmap_single_vma(&tlb, vma, address, range.end, details); 1585ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(&range); 1586ae8eba8bSWill Deacon tlb_finish_mmu(&tlb); 15871da177e4SLinus Torvalds } 15881da177e4SLinus Torvalds 1589c627f9ccSJack Steiner /** 1590c627f9ccSJack Steiner * zap_vma_ptes - remove ptes mapping the vma 1591c627f9ccSJack Steiner * @vma: vm_area_struct holding ptes to be zapped 1592c627f9ccSJack Steiner * @address: starting address of pages to zap 1593c627f9ccSJack Steiner * @size: number of bytes to zap 1594c627f9ccSJack Steiner * 1595c627f9ccSJack Steiner * This function only unmaps ptes assigned to VM_PFNMAP vmas. 1596c627f9ccSJack Steiner * 1597c627f9ccSJack Steiner * The entire address range must be fully contained within the vma. 1598c627f9ccSJack Steiner * 1599c627f9ccSJack Steiner */ 160027d036e3SLeon Romanovsky void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, 1601c627f9ccSJack Steiner unsigned long size) 1602c627f9ccSJack Steiner { 1603c627f9ccSJack Steiner if (address < vma->vm_start || address + size > vma->vm_end || 1604c627f9ccSJack Steiner !(vma->vm_flags & VM_PFNMAP)) 160527d036e3SLeon Romanovsky return; 160627d036e3SLeon Romanovsky 1607f5cc4eefSAl Viro zap_page_range_single(vma, address, size, NULL); 1608c627f9ccSJack Steiner } 1609c627f9ccSJack Steiner EXPORT_SYMBOL_GPL(zap_vma_ptes); 1610c627f9ccSJack Steiner 16118cd3984dSArjun Roy static pmd_t *walk_to_pmd(struct mm_struct *mm, unsigned long addr) 1612c9cfcddfSLinus Torvalds { 1613c2febafcSKirill A. Shutemov pgd_t *pgd; 1614c2febafcSKirill A. Shutemov p4d_t *p4d; 1615c2febafcSKirill A. Shutemov pud_t *pud; 1616c2febafcSKirill A. Shutemov pmd_t *pmd; 1617c2febafcSKirill A. Shutemov 1618c2febafcSKirill A. Shutemov pgd = pgd_offset(mm, addr); 1619c2febafcSKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 1620c2febafcSKirill A. Shutemov if (!p4d) 1621c2febafcSKirill A. Shutemov return NULL; 1622c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 1623c2febafcSKirill A. Shutemov if (!pud) 1624c2febafcSKirill A. Shutemov return NULL; 1625c2febafcSKirill A. Shutemov pmd = pmd_alloc(mm, pud, addr); 1626c2febafcSKirill A. Shutemov if (!pmd) 1627c2febafcSKirill A. Shutemov return NULL; 1628c2febafcSKirill A. Shutemov 1629f66055abSAndrea Arcangeli VM_BUG_ON(pmd_trans_huge(*pmd)); 16308cd3984dSArjun Roy return pmd; 16318cd3984dSArjun Roy } 16328cd3984dSArjun Roy 16338cd3984dSArjun Roy pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr, 16348cd3984dSArjun Roy spinlock_t **ptl) 16358cd3984dSArjun Roy { 16368cd3984dSArjun Roy pmd_t *pmd = walk_to_pmd(mm, addr); 16378cd3984dSArjun Roy 16388cd3984dSArjun Roy if (!pmd) 16398cd3984dSArjun Roy return NULL; 1640c9cfcddfSLinus Torvalds return pte_alloc_map_lock(mm, pmd, addr, ptl); 1641c9cfcddfSLinus Torvalds } 1642c9cfcddfSLinus Torvalds 16438efd6f5bSArjun Roy static int validate_page_before_insert(struct page *page) 16448efd6f5bSArjun Roy { 16458efd6f5bSArjun Roy if (PageAnon(page) || PageSlab(page) || page_has_type(page)) 16468efd6f5bSArjun Roy return -EINVAL; 16478efd6f5bSArjun Roy flush_dcache_page(page); 16488efd6f5bSArjun Roy return 0; 16498efd6f5bSArjun Roy } 16508efd6f5bSArjun Roy 16518efd6f5bSArjun Roy static int insert_page_into_pte_locked(struct mm_struct *mm, pte_t *pte, 16528efd6f5bSArjun Roy unsigned long addr, struct page *page, pgprot_t prot) 16538efd6f5bSArjun Roy { 16548efd6f5bSArjun Roy if (!pte_none(*pte)) 16558efd6f5bSArjun Roy return -EBUSY; 16568efd6f5bSArjun Roy /* Ok, finally just insert the thing.. */ 16578efd6f5bSArjun Roy get_page(page); 16588efd6f5bSArjun Roy inc_mm_counter_fast(mm, mm_counter_file(page)); 16598efd6f5bSArjun Roy page_add_file_rmap(page, false); 16608efd6f5bSArjun Roy set_pte_at(mm, addr, pte, mk_pte(page, prot)); 16618efd6f5bSArjun Roy return 0; 16628efd6f5bSArjun Roy } 16638efd6f5bSArjun Roy 16641da177e4SLinus Torvalds /* 1665238f58d8SLinus Torvalds * This is the old fallback for page remapping. 1666238f58d8SLinus Torvalds * 1667238f58d8SLinus Torvalds * For historical reasons, it only allows reserved pages. Only 1668238f58d8SLinus Torvalds * old drivers should use this, and they needed to mark their 1669238f58d8SLinus Torvalds * pages reserved for the old functions anyway. 1670238f58d8SLinus Torvalds */ 1671423bad60SNick Piggin static int insert_page(struct vm_area_struct *vma, unsigned long addr, 1672423bad60SNick Piggin struct page *page, pgprot_t prot) 1673238f58d8SLinus Torvalds { 1674423bad60SNick Piggin struct mm_struct *mm = vma->vm_mm; 1675238f58d8SLinus Torvalds int retval; 1676238f58d8SLinus Torvalds pte_t *pte; 1677238f58d8SLinus Torvalds spinlock_t *ptl; 1678238f58d8SLinus Torvalds 16798efd6f5bSArjun Roy retval = validate_page_before_insert(page); 16808efd6f5bSArjun Roy if (retval) 16815b4e655eSKAMEZAWA Hiroyuki goto out; 1682238f58d8SLinus Torvalds retval = -ENOMEM; 1683c9cfcddfSLinus Torvalds pte = get_locked_pte(mm, addr, &ptl); 1684238f58d8SLinus Torvalds if (!pte) 16855b4e655eSKAMEZAWA Hiroyuki goto out; 16868efd6f5bSArjun Roy retval = insert_page_into_pte_locked(mm, pte, addr, page, prot); 1687238f58d8SLinus Torvalds pte_unmap_unlock(pte, ptl); 1688238f58d8SLinus Torvalds out: 1689238f58d8SLinus Torvalds return retval; 1690238f58d8SLinus Torvalds } 1691238f58d8SLinus Torvalds 16928cd3984dSArjun Roy #ifdef pte_index 16937f70c2a6SArjun Roy static int insert_page_in_batch_locked(struct mm_struct *mm, pte_t *pte, 16948cd3984dSArjun Roy unsigned long addr, struct page *page, pgprot_t prot) 16958cd3984dSArjun Roy { 16968cd3984dSArjun Roy int err; 16978cd3984dSArjun Roy 16988cd3984dSArjun Roy if (!page_count(page)) 16998cd3984dSArjun Roy return -EINVAL; 17008cd3984dSArjun Roy err = validate_page_before_insert(page); 17017f70c2a6SArjun Roy if (err) 17027f70c2a6SArjun Roy return err; 17037f70c2a6SArjun Roy return insert_page_into_pte_locked(mm, pte, addr, page, prot); 17048cd3984dSArjun Roy } 17058cd3984dSArjun Roy 17068cd3984dSArjun Roy /* insert_pages() amortizes the cost of spinlock operations 17078cd3984dSArjun Roy * when inserting pages in a loop. Arch *must* define pte_index. 17088cd3984dSArjun Roy */ 17098cd3984dSArjun Roy static int insert_pages(struct vm_area_struct *vma, unsigned long addr, 17108cd3984dSArjun Roy struct page **pages, unsigned long *num, pgprot_t prot) 17118cd3984dSArjun Roy { 17128cd3984dSArjun Roy pmd_t *pmd = NULL; 17137f70c2a6SArjun Roy pte_t *start_pte, *pte; 17147f70c2a6SArjun Roy spinlock_t *pte_lock; 17158cd3984dSArjun Roy struct mm_struct *const mm = vma->vm_mm; 17168cd3984dSArjun Roy unsigned long curr_page_idx = 0; 17178cd3984dSArjun Roy unsigned long remaining_pages_total = *num; 17188cd3984dSArjun Roy unsigned long pages_to_write_in_pmd; 17198cd3984dSArjun Roy int ret; 17208cd3984dSArjun Roy more: 17218cd3984dSArjun Roy ret = -EFAULT; 17228cd3984dSArjun Roy pmd = walk_to_pmd(mm, addr); 17238cd3984dSArjun Roy if (!pmd) 17248cd3984dSArjun Roy goto out; 17258cd3984dSArjun Roy 17268cd3984dSArjun Roy pages_to_write_in_pmd = min_t(unsigned long, 17278cd3984dSArjun Roy remaining_pages_total, PTRS_PER_PTE - pte_index(addr)); 17288cd3984dSArjun Roy 17298cd3984dSArjun Roy /* Allocate the PTE if necessary; takes PMD lock once only. */ 17308cd3984dSArjun Roy ret = -ENOMEM; 17318cd3984dSArjun Roy if (pte_alloc(mm, pmd)) 17328cd3984dSArjun Roy goto out; 17338cd3984dSArjun Roy 17348cd3984dSArjun Roy while (pages_to_write_in_pmd) { 17358cd3984dSArjun Roy int pte_idx = 0; 17368cd3984dSArjun Roy const int batch_size = min_t(int, pages_to_write_in_pmd, 8); 17378cd3984dSArjun Roy 17387f70c2a6SArjun Roy start_pte = pte_offset_map_lock(mm, pmd, addr, &pte_lock); 17397f70c2a6SArjun Roy for (pte = start_pte; pte_idx < batch_size; ++pte, ++pte_idx) { 17407f70c2a6SArjun Roy int err = insert_page_in_batch_locked(mm, pte, 17418cd3984dSArjun Roy addr, pages[curr_page_idx], prot); 17428cd3984dSArjun Roy if (unlikely(err)) { 17437f70c2a6SArjun Roy pte_unmap_unlock(start_pte, pte_lock); 17448cd3984dSArjun Roy ret = err; 17458cd3984dSArjun Roy remaining_pages_total -= pte_idx; 17468cd3984dSArjun Roy goto out; 17478cd3984dSArjun Roy } 17488cd3984dSArjun Roy addr += PAGE_SIZE; 17498cd3984dSArjun Roy ++curr_page_idx; 17508cd3984dSArjun Roy } 17517f70c2a6SArjun Roy pte_unmap_unlock(start_pte, pte_lock); 17528cd3984dSArjun Roy pages_to_write_in_pmd -= batch_size; 17538cd3984dSArjun Roy remaining_pages_total -= batch_size; 17548cd3984dSArjun Roy } 17558cd3984dSArjun Roy if (remaining_pages_total) 17568cd3984dSArjun Roy goto more; 17578cd3984dSArjun Roy ret = 0; 17588cd3984dSArjun Roy out: 17598cd3984dSArjun Roy *num = remaining_pages_total; 17608cd3984dSArjun Roy return ret; 17618cd3984dSArjun Roy } 17628cd3984dSArjun Roy #endif /* ifdef pte_index */ 17638cd3984dSArjun Roy 17648cd3984dSArjun Roy /** 17658cd3984dSArjun Roy * vm_insert_pages - insert multiple pages into user vma, batching the pmd lock. 17668cd3984dSArjun Roy * @vma: user vma to map to 17678cd3984dSArjun Roy * @addr: target start user address of these pages 17688cd3984dSArjun Roy * @pages: source kernel pages 17698cd3984dSArjun Roy * @num: in: number of pages to map. out: number of pages that were *not* 17708cd3984dSArjun Roy * mapped. (0 means all pages were successfully mapped). 17718cd3984dSArjun Roy * 17728cd3984dSArjun Roy * Preferred over vm_insert_page() when inserting multiple pages. 17738cd3984dSArjun Roy * 17748cd3984dSArjun Roy * In case of error, we may have mapped a subset of the provided 17758cd3984dSArjun Roy * pages. It is the caller's responsibility to account for this case. 17768cd3984dSArjun Roy * 17778cd3984dSArjun Roy * The same restrictions apply as in vm_insert_page(). 17788cd3984dSArjun Roy */ 17798cd3984dSArjun Roy int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr, 17808cd3984dSArjun Roy struct page **pages, unsigned long *num) 17818cd3984dSArjun Roy { 17828cd3984dSArjun Roy #ifdef pte_index 17838cd3984dSArjun Roy const unsigned long end_addr = addr + (*num * PAGE_SIZE) - 1; 17848cd3984dSArjun Roy 17858cd3984dSArjun Roy if (addr < vma->vm_start || end_addr >= vma->vm_end) 17868cd3984dSArjun Roy return -EFAULT; 17878cd3984dSArjun Roy if (!(vma->vm_flags & VM_MIXEDMAP)) { 1788d8ed45c5SMichel Lespinasse BUG_ON(mmap_read_trylock(vma->vm_mm)); 17898cd3984dSArjun Roy BUG_ON(vma->vm_flags & VM_PFNMAP); 17908cd3984dSArjun Roy vma->vm_flags |= VM_MIXEDMAP; 17918cd3984dSArjun Roy } 17928cd3984dSArjun Roy /* Defer page refcount checking till we're about to map that page. */ 17938cd3984dSArjun Roy return insert_pages(vma, addr, pages, num, vma->vm_page_prot); 17948cd3984dSArjun Roy #else 17958cd3984dSArjun Roy unsigned long idx = 0, pgcount = *num; 179645779b03STom Rix int err = -EINVAL; 17978cd3984dSArjun Roy 17988cd3984dSArjun Roy for (; idx < pgcount; ++idx) { 17998cd3984dSArjun Roy err = vm_insert_page(vma, addr + (PAGE_SIZE * idx), pages[idx]); 18008cd3984dSArjun Roy if (err) 18018cd3984dSArjun Roy break; 18028cd3984dSArjun Roy } 18038cd3984dSArjun Roy *num = pgcount - idx; 18048cd3984dSArjun Roy return err; 18058cd3984dSArjun Roy #endif /* ifdef pte_index */ 18068cd3984dSArjun Roy } 18078cd3984dSArjun Roy EXPORT_SYMBOL(vm_insert_pages); 18088cd3984dSArjun Roy 1809bfa5bf6dSRolf Eike Beer /** 1810bfa5bf6dSRolf Eike Beer * vm_insert_page - insert single page into user vma 1811bfa5bf6dSRolf Eike Beer * @vma: user vma to map to 1812bfa5bf6dSRolf Eike Beer * @addr: target user address of this page 1813bfa5bf6dSRolf Eike Beer * @page: source kernel page 1814bfa5bf6dSRolf Eike Beer * 1815a145dd41SLinus Torvalds * This allows drivers to insert individual pages they've allocated 1816a145dd41SLinus Torvalds * into a user vma. 1817a145dd41SLinus Torvalds * 1818a145dd41SLinus Torvalds * The page has to be a nice clean _individual_ kernel allocation. 1819a145dd41SLinus Torvalds * If you allocate a compound page, you need to have marked it as 1820a145dd41SLinus Torvalds * such (__GFP_COMP), or manually just split the page up yourself 18218dfcc9baSNick Piggin * (see split_page()). 1822a145dd41SLinus Torvalds * 1823a145dd41SLinus Torvalds * NOTE! Traditionally this was done with "remap_pfn_range()" which 1824a145dd41SLinus Torvalds * took an arbitrary page protection parameter. This doesn't allow 1825a145dd41SLinus Torvalds * that. Your vma protection will have to be set up correctly, which 1826a145dd41SLinus Torvalds * means that if you want a shared writable mapping, you'd better 1827a145dd41SLinus Torvalds * ask for a shared writable mapping! 1828a145dd41SLinus Torvalds * 1829a145dd41SLinus Torvalds * The page does not need to be reserved. 18304b6e1e37SKonstantin Khlebnikov * 18314b6e1e37SKonstantin Khlebnikov * Usually this function is called from f_op->mmap() handler 1832c1e8d7c6SMichel Lespinasse * under mm->mmap_lock write-lock, so it can change vma->vm_flags. 18334b6e1e37SKonstantin Khlebnikov * Caller must set VM_MIXEDMAP on vma if it wants to call this 18344b6e1e37SKonstantin Khlebnikov * function from other places, for example from page-fault handler. 1835a862f68aSMike Rapoport * 1836a862f68aSMike Rapoport * Return: %0 on success, negative error code otherwise. 1837a145dd41SLinus Torvalds */ 1838423bad60SNick Piggin int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 1839423bad60SNick Piggin struct page *page) 1840a145dd41SLinus Torvalds { 1841a145dd41SLinus Torvalds if (addr < vma->vm_start || addr >= vma->vm_end) 1842a145dd41SLinus Torvalds return -EFAULT; 1843a145dd41SLinus Torvalds if (!page_count(page)) 1844a145dd41SLinus Torvalds return -EINVAL; 18454b6e1e37SKonstantin Khlebnikov if (!(vma->vm_flags & VM_MIXEDMAP)) { 1846d8ed45c5SMichel Lespinasse BUG_ON(mmap_read_trylock(vma->vm_mm)); 18474b6e1e37SKonstantin Khlebnikov BUG_ON(vma->vm_flags & VM_PFNMAP); 18484b6e1e37SKonstantin Khlebnikov vma->vm_flags |= VM_MIXEDMAP; 18494b6e1e37SKonstantin Khlebnikov } 1850423bad60SNick Piggin return insert_page(vma, addr, page, vma->vm_page_prot); 1851a145dd41SLinus Torvalds } 1852e3c3374fSLinus Torvalds EXPORT_SYMBOL(vm_insert_page); 1853a145dd41SLinus Torvalds 1854a667d745SSouptick Joarder /* 1855a667d745SSouptick Joarder * __vm_map_pages - maps range of kernel pages into user vma 1856a667d745SSouptick Joarder * @vma: user vma to map to 1857a667d745SSouptick Joarder * @pages: pointer to array of source kernel pages 1858a667d745SSouptick Joarder * @num: number of pages in page array 1859a667d745SSouptick Joarder * @offset: user's requested vm_pgoff 1860a667d745SSouptick Joarder * 1861a667d745SSouptick Joarder * This allows drivers to map range of kernel pages into a user vma. 1862a667d745SSouptick Joarder * 1863a667d745SSouptick Joarder * Return: 0 on success and error code otherwise. 1864a667d745SSouptick Joarder */ 1865a667d745SSouptick Joarder static int __vm_map_pages(struct vm_area_struct *vma, struct page **pages, 1866a667d745SSouptick Joarder unsigned long num, unsigned long offset) 1867a667d745SSouptick Joarder { 1868a667d745SSouptick Joarder unsigned long count = vma_pages(vma); 1869a667d745SSouptick Joarder unsigned long uaddr = vma->vm_start; 1870a667d745SSouptick Joarder int ret, i; 1871a667d745SSouptick Joarder 1872a667d745SSouptick Joarder /* Fail if the user requested offset is beyond the end of the object */ 187396756fcbSMiguel Ojeda if (offset >= num) 1874a667d745SSouptick Joarder return -ENXIO; 1875a667d745SSouptick Joarder 1876a667d745SSouptick Joarder /* Fail if the user requested size exceeds available object size */ 1877a667d745SSouptick Joarder if (count > num - offset) 1878a667d745SSouptick Joarder return -ENXIO; 1879a667d745SSouptick Joarder 1880a667d745SSouptick Joarder for (i = 0; i < count; i++) { 1881a667d745SSouptick Joarder ret = vm_insert_page(vma, uaddr, pages[offset + i]); 1882a667d745SSouptick Joarder if (ret < 0) 1883a667d745SSouptick Joarder return ret; 1884a667d745SSouptick Joarder uaddr += PAGE_SIZE; 1885a667d745SSouptick Joarder } 1886a667d745SSouptick Joarder 1887a667d745SSouptick Joarder return 0; 1888a667d745SSouptick Joarder } 1889a667d745SSouptick Joarder 1890a667d745SSouptick Joarder /** 1891a667d745SSouptick Joarder * vm_map_pages - maps range of kernel pages starts with non zero offset 1892a667d745SSouptick Joarder * @vma: user vma to map to 1893a667d745SSouptick Joarder * @pages: pointer to array of source kernel pages 1894a667d745SSouptick Joarder * @num: number of pages in page array 1895a667d745SSouptick Joarder * 1896a667d745SSouptick Joarder * Maps an object consisting of @num pages, catering for the user's 1897a667d745SSouptick Joarder * requested vm_pgoff 1898a667d745SSouptick Joarder * 1899a667d745SSouptick Joarder * If we fail to insert any page into the vma, the function will return 1900a667d745SSouptick Joarder * immediately leaving any previously inserted pages present. Callers 1901a667d745SSouptick Joarder * from the mmap handler may immediately return the error as their caller 1902a667d745SSouptick Joarder * will destroy the vma, removing any successfully inserted pages. Other 1903a667d745SSouptick Joarder * callers should make their own arrangements for calling unmap_region(). 1904a667d745SSouptick Joarder * 1905a667d745SSouptick Joarder * Context: Process context. Called by mmap handlers. 1906a667d745SSouptick Joarder * Return: 0 on success and error code otherwise. 1907a667d745SSouptick Joarder */ 1908a667d745SSouptick Joarder int vm_map_pages(struct vm_area_struct *vma, struct page **pages, 1909a667d745SSouptick Joarder unsigned long num) 1910a667d745SSouptick Joarder { 1911a667d745SSouptick Joarder return __vm_map_pages(vma, pages, num, vma->vm_pgoff); 1912a667d745SSouptick Joarder } 1913a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages); 1914a667d745SSouptick Joarder 1915a667d745SSouptick Joarder /** 1916a667d745SSouptick Joarder * vm_map_pages_zero - map range of kernel pages starts with zero offset 1917a667d745SSouptick Joarder * @vma: user vma to map to 1918a667d745SSouptick Joarder * @pages: pointer to array of source kernel pages 1919a667d745SSouptick Joarder * @num: number of pages in page array 1920a667d745SSouptick Joarder * 1921a667d745SSouptick Joarder * Similar to vm_map_pages(), except that it explicitly sets the offset 1922a667d745SSouptick Joarder * to 0. This function is intended for the drivers that did not consider 1923a667d745SSouptick Joarder * vm_pgoff. 1924a667d745SSouptick Joarder * 1925a667d745SSouptick Joarder * Context: Process context. Called by mmap handlers. 1926a667d745SSouptick Joarder * Return: 0 on success and error code otherwise. 1927a667d745SSouptick Joarder */ 1928a667d745SSouptick Joarder int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, 1929a667d745SSouptick Joarder unsigned long num) 1930a667d745SSouptick Joarder { 1931a667d745SSouptick Joarder return __vm_map_pages(vma, pages, num, 0); 1932a667d745SSouptick Joarder } 1933a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages_zero); 1934a667d745SSouptick Joarder 19359b5a8e00SMatthew Wilcox static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr, 1936b2770da6SRoss Zwisler pfn_t pfn, pgprot_t prot, bool mkwrite) 1937423bad60SNick Piggin { 1938423bad60SNick Piggin struct mm_struct *mm = vma->vm_mm; 1939423bad60SNick Piggin pte_t *pte, entry; 1940423bad60SNick Piggin spinlock_t *ptl; 1941423bad60SNick Piggin 1942423bad60SNick Piggin pte = get_locked_pte(mm, addr, &ptl); 1943423bad60SNick Piggin if (!pte) 19449b5a8e00SMatthew Wilcox return VM_FAULT_OOM; 1945b2770da6SRoss Zwisler if (!pte_none(*pte)) { 1946b2770da6SRoss Zwisler if (mkwrite) { 1947b2770da6SRoss Zwisler /* 1948b2770da6SRoss Zwisler * For read faults on private mappings the PFN passed 1949b2770da6SRoss Zwisler * in may not match the PFN we have mapped if the 1950b2770da6SRoss Zwisler * mapped PFN is a writeable COW page. In the mkwrite 1951b2770da6SRoss Zwisler * case we are creating a writable PTE for a shared 1952f2c57d91SJan Kara * mapping and we expect the PFNs to match. If they 1953f2c57d91SJan Kara * don't match, we are likely racing with block 1954f2c57d91SJan Kara * allocation and mapping invalidation so just skip the 1955f2c57d91SJan Kara * update. 1956b2770da6SRoss Zwisler */ 1957f2c57d91SJan Kara if (pte_pfn(*pte) != pfn_t_to_pfn(pfn)) { 1958f2c57d91SJan Kara WARN_ON_ONCE(!is_zero_pfn(pte_pfn(*pte))); 1959423bad60SNick Piggin goto out_unlock; 1960f2c57d91SJan Kara } 1961cae85cb8SJan Kara entry = pte_mkyoung(*pte); 1962cae85cb8SJan Kara entry = maybe_mkwrite(pte_mkdirty(entry), vma); 1963cae85cb8SJan Kara if (ptep_set_access_flags(vma, addr, pte, entry, 1)) 1964cae85cb8SJan Kara update_mmu_cache(vma, addr, pte); 1965cae85cb8SJan Kara } 1966b2770da6SRoss Zwisler goto out_unlock; 1967b2770da6SRoss Zwisler } 1968423bad60SNick Piggin 1969423bad60SNick Piggin /* Ok, finally just insert the thing.. */ 197001c8f1c4SDan Williams if (pfn_t_devmap(pfn)) 197101c8f1c4SDan Williams entry = pte_mkdevmap(pfn_t_pte(pfn, prot)); 197201c8f1c4SDan Williams else 197301c8f1c4SDan Williams entry = pte_mkspecial(pfn_t_pte(pfn, prot)); 1974b2770da6SRoss Zwisler 1975b2770da6SRoss Zwisler if (mkwrite) { 1976b2770da6SRoss Zwisler entry = pte_mkyoung(entry); 1977b2770da6SRoss Zwisler entry = maybe_mkwrite(pte_mkdirty(entry), vma); 1978b2770da6SRoss Zwisler } 1979b2770da6SRoss Zwisler 1980423bad60SNick Piggin set_pte_at(mm, addr, pte, entry); 19814b3073e1SRussell King update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */ 1982423bad60SNick Piggin 1983423bad60SNick Piggin out_unlock: 1984423bad60SNick Piggin pte_unmap_unlock(pte, ptl); 19859b5a8e00SMatthew Wilcox return VM_FAULT_NOPAGE; 1986423bad60SNick Piggin } 1987423bad60SNick Piggin 1988f5e6d1d5SMatthew Wilcox /** 1989f5e6d1d5SMatthew Wilcox * vmf_insert_pfn_prot - insert single pfn into user vma with specified pgprot 1990f5e6d1d5SMatthew Wilcox * @vma: user vma to map to 1991f5e6d1d5SMatthew Wilcox * @addr: target user address of this page 1992f5e6d1d5SMatthew Wilcox * @pfn: source kernel pfn 1993f5e6d1d5SMatthew Wilcox * @pgprot: pgprot flags for the inserted page 1994f5e6d1d5SMatthew Wilcox * 1995a1a0aea5SRandy Dunlap * This is exactly like vmf_insert_pfn(), except that it allows drivers 1996f5e6d1d5SMatthew Wilcox * to override pgprot on a per-page basis. 1997f5e6d1d5SMatthew Wilcox * 1998f5e6d1d5SMatthew Wilcox * This only makes sense for IO mappings, and it makes no sense for 1999f5e6d1d5SMatthew Wilcox * COW mappings. In general, using multiple vmas is preferable; 2000ae2b01f3SMatthew Wilcox * vmf_insert_pfn_prot should only be used if using multiple VMAs is 2001f5e6d1d5SMatthew Wilcox * impractical. 2002f5e6d1d5SMatthew Wilcox * 2003574c5b3dSThomas Hellstrom * See vmf_insert_mixed_prot() for a discussion of the implication of using 2004574c5b3dSThomas Hellstrom * a value of @pgprot different from that of @vma->vm_page_prot. 2005574c5b3dSThomas Hellstrom * 2006ae2b01f3SMatthew Wilcox * Context: Process context. May allocate using %GFP_KERNEL. 2007f5e6d1d5SMatthew Wilcox * Return: vm_fault_t value. 2008f5e6d1d5SMatthew Wilcox */ 2009f5e6d1d5SMatthew Wilcox vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr, 2010f5e6d1d5SMatthew Wilcox unsigned long pfn, pgprot_t pgprot) 2011f5e6d1d5SMatthew Wilcox { 20126d958546SMatthew Wilcox /* 20136d958546SMatthew Wilcox * Technically, architectures with pte_special can avoid all these 20146d958546SMatthew Wilcox * restrictions (same for remap_pfn_range). However we would like 20156d958546SMatthew Wilcox * consistency in testing and feature parity among all, so we should 20166d958546SMatthew Wilcox * try to keep these invariants in place for everybody. 20176d958546SMatthew Wilcox */ 20186d958546SMatthew Wilcox BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))); 20196d958546SMatthew Wilcox BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == 20206d958546SMatthew Wilcox (VM_PFNMAP|VM_MIXEDMAP)); 20216d958546SMatthew Wilcox BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); 20226d958546SMatthew Wilcox BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn)); 20236d958546SMatthew Wilcox 20246d958546SMatthew Wilcox if (addr < vma->vm_start || addr >= vma->vm_end) 20256d958546SMatthew Wilcox return VM_FAULT_SIGBUS; 20266d958546SMatthew Wilcox 20276d958546SMatthew Wilcox if (!pfn_modify_allowed(pfn, pgprot)) 20286d958546SMatthew Wilcox return VM_FAULT_SIGBUS; 20296d958546SMatthew Wilcox 20306d958546SMatthew Wilcox track_pfn_insert(vma, &pgprot, __pfn_to_pfn_t(pfn, PFN_DEV)); 20316d958546SMatthew Wilcox 20329b5a8e00SMatthew Wilcox return insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot, 20336d958546SMatthew Wilcox false); 2034f5e6d1d5SMatthew Wilcox } 2035f5e6d1d5SMatthew Wilcox EXPORT_SYMBOL(vmf_insert_pfn_prot); 2036e0dc0d8fSNick Piggin 2037ae2b01f3SMatthew Wilcox /** 2038ae2b01f3SMatthew Wilcox * vmf_insert_pfn - insert single pfn into user vma 2039ae2b01f3SMatthew Wilcox * @vma: user vma to map to 2040ae2b01f3SMatthew Wilcox * @addr: target user address of this page 2041ae2b01f3SMatthew Wilcox * @pfn: source kernel pfn 2042ae2b01f3SMatthew Wilcox * 2043ae2b01f3SMatthew Wilcox * Similar to vm_insert_page, this allows drivers to insert individual pages 2044ae2b01f3SMatthew Wilcox * they've allocated into a user vma. Same comments apply. 2045ae2b01f3SMatthew Wilcox * 2046ae2b01f3SMatthew Wilcox * This function should only be called from a vm_ops->fault handler, and 2047ae2b01f3SMatthew Wilcox * in that case the handler should return the result of this function. 2048ae2b01f3SMatthew Wilcox * 2049ae2b01f3SMatthew Wilcox * vma cannot be a COW mapping. 2050ae2b01f3SMatthew Wilcox * 2051ae2b01f3SMatthew Wilcox * As this is called only for pages that do not currently exist, we 2052ae2b01f3SMatthew Wilcox * do not need to flush old virtual caches or the TLB. 2053ae2b01f3SMatthew Wilcox * 2054ae2b01f3SMatthew Wilcox * Context: Process context. May allocate using %GFP_KERNEL. 2055ae2b01f3SMatthew Wilcox * Return: vm_fault_t value. 2056ae2b01f3SMatthew Wilcox */ 2057ae2b01f3SMatthew Wilcox vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr, 2058ae2b01f3SMatthew Wilcox unsigned long pfn) 2059ae2b01f3SMatthew Wilcox { 2060ae2b01f3SMatthew Wilcox return vmf_insert_pfn_prot(vma, addr, pfn, vma->vm_page_prot); 2061ae2b01f3SMatthew Wilcox } 2062ae2b01f3SMatthew Wilcox EXPORT_SYMBOL(vmf_insert_pfn); 2063ae2b01f3SMatthew Wilcox 2064785a3fabSDan Williams static bool vm_mixed_ok(struct vm_area_struct *vma, pfn_t pfn) 2065785a3fabSDan Williams { 2066785a3fabSDan Williams /* these checks mirror the abort conditions in vm_normal_page */ 2067785a3fabSDan Williams if (vma->vm_flags & VM_MIXEDMAP) 2068785a3fabSDan Williams return true; 2069785a3fabSDan Williams if (pfn_t_devmap(pfn)) 2070785a3fabSDan Williams return true; 2071785a3fabSDan Williams if (pfn_t_special(pfn)) 2072785a3fabSDan Williams return true; 2073785a3fabSDan Williams if (is_zero_pfn(pfn_t_to_pfn(pfn))) 2074785a3fabSDan Williams return true; 2075785a3fabSDan Williams return false; 2076785a3fabSDan Williams } 2077785a3fabSDan Williams 207879f3aa5bSMatthew Wilcox static vm_fault_t __vm_insert_mixed(struct vm_area_struct *vma, 2079574c5b3dSThomas Hellstrom unsigned long addr, pfn_t pfn, pgprot_t pgprot, 2080574c5b3dSThomas Hellstrom bool mkwrite) 2081423bad60SNick Piggin { 208279f3aa5bSMatthew Wilcox int err; 208387744ab3SDan Williams 2084785a3fabSDan Williams BUG_ON(!vm_mixed_ok(vma, pfn)); 2085423bad60SNick Piggin 2086423bad60SNick Piggin if (addr < vma->vm_start || addr >= vma->vm_end) 208779f3aa5bSMatthew Wilcox return VM_FAULT_SIGBUS; 2088308a047cSBorislav Petkov 2089308a047cSBorislav Petkov track_pfn_insert(vma, &pgprot, pfn); 2090423bad60SNick Piggin 209142e4089cSAndi Kleen if (!pfn_modify_allowed(pfn_t_to_pfn(pfn), pgprot)) 209279f3aa5bSMatthew Wilcox return VM_FAULT_SIGBUS; 209342e4089cSAndi Kleen 2094423bad60SNick Piggin /* 2095423bad60SNick Piggin * If we don't have pte special, then we have to use the pfn_valid() 2096423bad60SNick Piggin * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must* 2097423bad60SNick Piggin * refcount the page if pfn_valid is true (hence insert_page rather 209862eede62SHugh Dickins * than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP 209962eede62SHugh Dickins * without pte special, it would there be refcounted as a normal page. 2100423bad60SNick Piggin */ 210100b3a331SLaurent Dufour if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL) && 210200b3a331SLaurent Dufour !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) { 2103423bad60SNick Piggin struct page *page; 2104423bad60SNick Piggin 210503fc2da6SDan Williams /* 210603fc2da6SDan Williams * At this point we are committed to insert_page() 210703fc2da6SDan Williams * regardless of whether the caller specified flags that 210803fc2da6SDan Williams * result in pfn_t_has_page() == false. 210903fc2da6SDan Williams */ 211003fc2da6SDan Williams page = pfn_to_page(pfn_t_to_pfn(pfn)); 211179f3aa5bSMatthew Wilcox err = insert_page(vma, addr, page, pgprot); 211279f3aa5bSMatthew Wilcox } else { 21139b5a8e00SMatthew Wilcox return insert_pfn(vma, addr, pfn, pgprot, mkwrite); 2114423bad60SNick Piggin } 2115b2770da6SRoss Zwisler 21165d747637SMatthew Wilcox if (err == -ENOMEM) 21175d747637SMatthew Wilcox return VM_FAULT_OOM; 21185d747637SMatthew Wilcox if (err < 0 && err != -EBUSY) 21195d747637SMatthew Wilcox return VM_FAULT_SIGBUS; 21205d747637SMatthew Wilcox 21215d747637SMatthew Wilcox return VM_FAULT_NOPAGE; 2122423bad60SNick Piggin } 212379f3aa5bSMatthew Wilcox 2124574c5b3dSThomas Hellstrom /** 2125574c5b3dSThomas Hellstrom * vmf_insert_mixed_prot - insert single pfn into user vma with specified pgprot 2126574c5b3dSThomas Hellstrom * @vma: user vma to map to 2127574c5b3dSThomas Hellstrom * @addr: target user address of this page 2128574c5b3dSThomas Hellstrom * @pfn: source kernel pfn 2129574c5b3dSThomas Hellstrom * @pgprot: pgprot flags for the inserted page 2130574c5b3dSThomas Hellstrom * 2131a1a0aea5SRandy Dunlap * This is exactly like vmf_insert_mixed(), except that it allows drivers 2132574c5b3dSThomas Hellstrom * to override pgprot on a per-page basis. 2133574c5b3dSThomas Hellstrom * 2134574c5b3dSThomas Hellstrom * Typically this function should be used by drivers to set caching- and 2135574c5b3dSThomas Hellstrom * encryption bits different than those of @vma->vm_page_prot, because 2136574c5b3dSThomas Hellstrom * the caching- or encryption mode may not be known at mmap() time. 2137574c5b3dSThomas Hellstrom * This is ok as long as @vma->vm_page_prot is not used by the core vm 2138574c5b3dSThomas Hellstrom * to set caching and encryption bits for those vmas (except for COW pages). 2139574c5b3dSThomas Hellstrom * This is ensured by core vm only modifying these page table entries using 2140574c5b3dSThomas Hellstrom * functions that don't touch caching- or encryption bits, using pte_modify() 2141574c5b3dSThomas Hellstrom * if needed. (See for example mprotect()). 2142574c5b3dSThomas Hellstrom * Also when new page-table entries are created, this is only done using the 2143574c5b3dSThomas Hellstrom * fault() callback, and never using the value of vma->vm_page_prot, 2144574c5b3dSThomas Hellstrom * except for page-table entries that point to anonymous pages as the result 2145574c5b3dSThomas Hellstrom * of COW. 2146574c5b3dSThomas Hellstrom * 2147574c5b3dSThomas Hellstrom * Context: Process context. May allocate using %GFP_KERNEL. 2148574c5b3dSThomas Hellstrom * Return: vm_fault_t value. 2149574c5b3dSThomas Hellstrom */ 2150574c5b3dSThomas Hellstrom vm_fault_t vmf_insert_mixed_prot(struct vm_area_struct *vma, unsigned long addr, 2151574c5b3dSThomas Hellstrom pfn_t pfn, pgprot_t pgprot) 2152574c5b3dSThomas Hellstrom { 2153574c5b3dSThomas Hellstrom return __vm_insert_mixed(vma, addr, pfn, pgprot, false); 2154574c5b3dSThomas Hellstrom } 21555379e4ddSThomas Hellstrom EXPORT_SYMBOL(vmf_insert_mixed_prot); 2156574c5b3dSThomas Hellstrom 215779f3aa5bSMatthew Wilcox vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr, 215879f3aa5bSMatthew Wilcox pfn_t pfn) 215979f3aa5bSMatthew Wilcox { 2160574c5b3dSThomas Hellstrom return __vm_insert_mixed(vma, addr, pfn, vma->vm_page_prot, false); 216179f3aa5bSMatthew Wilcox } 21625d747637SMatthew Wilcox EXPORT_SYMBOL(vmf_insert_mixed); 2163423bad60SNick Piggin 2164ab77dab4SSouptick Joarder /* 2165ab77dab4SSouptick Joarder * If the insertion of PTE failed because someone else already added a 2166ab77dab4SSouptick Joarder * different entry in the mean time, we treat that as success as we assume 2167ab77dab4SSouptick Joarder * the same entry was actually inserted. 2168ab77dab4SSouptick Joarder */ 2169ab77dab4SSouptick Joarder vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma, 2170ab77dab4SSouptick Joarder unsigned long addr, pfn_t pfn) 2171b2770da6SRoss Zwisler { 2172574c5b3dSThomas Hellstrom return __vm_insert_mixed(vma, addr, pfn, vma->vm_page_prot, true); 2173b2770da6SRoss Zwisler } 2174ab77dab4SSouptick Joarder EXPORT_SYMBOL(vmf_insert_mixed_mkwrite); 2175b2770da6SRoss Zwisler 2176a145dd41SLinus Torvalds /* 21771da177e4SLinus Torvalds * maps a range of physical memory into the requested pages. the old 21781da177e4SLinus Torvalds * mappings are removed. any references to nonexistent pages results 21791da177e4SLinus Torvalds * in null mappings (currently treated as "copy-on-access") 21801da177e4SLinus Torvalds */ 21811da177e4SLinus Torvalds static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd, 21821da177e4SLinus Torvalds unsigned long addr, unsigned long end, 21831da177e4SLinus Torvalds unsigned long pfn, pgprot_t prot) 21841da177e4SLinus Torvalds { 218590a3e375SMiaohe Lin pte_t *pte, *mapped_pte; 2186c74df32cSHugh Dickins spinlock_t *ptl; 218742e4089cSAndi Kleen int err = 0; 21881da177e4SLinus Torvalds 218990a3e375SMiaohe Lin mapped_pte = pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); 21901da177e4SLinus Torvalds if (!pte) 21911da177e4SLinus Torvalds return -ENOMEM; 21926606c3e0SZachary Amsden arch_enter_lazy_mmu_mode(); 21931da177e4SLinus Torvalds do { 21941da177e4SLinus Torvalds BUG_ON(!pte_none(*pte)); 219542e4089cSAndi Kleen if (!pfn_modify_allowed(pfn, prot)) { 219642e4089cSAndi Kleen err = -EACCES; 219742e4089cSAndi Kleen break; 219842e4089cSAndi Kleen } 21997e675137SNick Piggin set_pte_at(mm, addr, pte, pte_mkspecial(pfn_pte(pfn, prot))); 22001da177e4SLinus Torvalds pfn++; 22011da177e4SLinus Torvalds } while (pte++, addr += PAGE_SIZE, addr != end); 22026606c3e0SZachary Amsden arch_leave_lazy_mmu_mode(); 220390a3e375SMiaohe Lin pte_unmap_unlock(mapped_pte, ptl); 220442e4089cSAndi Kleen return err; 22051da177e4SLinus Torvalds } 22061da177e4SLinus Torvalds 22071da177e4SLinus Torvalds static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud, 22081da177e4SLinus Torvalds unsigned long addr, unsigned long end, 22091da177e4SLinus Torvalds unsigned long pfn, pgprot_t prot) 22101da177e4SLinus Torvalds { 22111da177e4SLinus Torvalds pmd_t *pmd; 22121da177e4SLinus Torvalds unsigned long next; 221342e4089cSAndi Kleen int err; 22141da177e4SLinus Torvalds 22151da177e4SLinus Torvalds pfn -= addr >> PAGE_SHIFT; 22161da177e4SLinus Torvalds pmd = pmd_alloc(mm, pud, addr); 22171da177e4SLinus Torvalds if (!pmd) 22181da177e4SLinus Torvalds return -ENOMEM; 2219f66055abSAndrea Arcangeli VM_BUG_ON(pmd_trans_huge(*pmd)); 22201da177e4SLinus Torvalds do { 22211da177e4SLinus Torvalds next = pmd_addr_end(addr, end); 222242e4089cSAndi Kleen err = remap_pte_range(mm, pmd, addr, next, 222342e4089cSAndi Kleen pfn + (addr >> PAGE_SHIFT), prot); 222442e4089cSAndi Kleen if (err) 222542e4089cSAndi Kleen return err; 22261da177e4SLinus Torvalds } while (pmd++, addr = next, addr != end); 22271da177e4SLinus Torvalds return 0; 22281da177e4SLinus Torvalds } 22291da177e4SLinus Torvalds 2230c2febafcSKirill A. Shutemov static inline int remap_pud_range(struct mm_struct *mm, p4d_t *p4d, 22311da177e4SLinus Torvalds unsigned long addr, unsigned long end, 22321da177e4SLinus Torvalds unsigned long pfn, pgprot_t prot) 22331da177e4SLinus Torvalds { 22341da177e4SLinus Torvalds pud_t *pud; 22351da177e4SLinus Torvalds unsigned long next; 223642e4089cSAndi Kleen int err; 22371da177e4SLinus Torvalds 22381da177e4SLinus Torvalds pfn -= addr >> PAGE_SHIFT; 2239c2febafcSKirill A. Shutemov pud = pud_alloc(mm, p4d, addr); 22401da177e4SLinus Torvalds if (!pud) 22411da177e4SLinus Torvalds return -ENOMEM; 22421da177e4SLinus Torvalds do { 22431da177e4SLinus Torvalds next = pud_addr_end(addr, end); 224442e4089cSAndi Kleen err = remap_pmd_range(mm, pud, addr, next, 224542e4089cSAndi Kleen pfn + (addr >> PAGE_SHIFT), prot); 224642e4089cSAndi Kleen if (err) 224742e4089cSAndi Kleen return err; 22481da177e4SLinus Torvalds } while (pud++, addr = next, addr != end); 22491da177e4SLinus Torvalds return 0; 22501da177e4SLinus Torvalds } 22511da177e4SLinus Torvalds 2252c2febafcSKirill A. Shutemov static inline int remap_p4d_range(struct mm_struct *mm, pgd_t *pgd, 2253c2febafcSKirill A. Shutemov unsigned long addr, unsigned long end, 2254c2febafcSKirill A. Shutemov unsigned long pfn, pgprot_t prot) 2255c2febafcSKirill A. Shutemov { 2256c2febafcSKirill A. Shutemov p4d_t *p4d; 2257c2febafcSKirill A. Shutemov unsigned long next; 225842e4089cSAndi Kleen int err; 2259c2febafcSKirill A. Shutemov 2260c2febafcSKirill A. Shutemov pfn -= addr >> PAGE_SHIFT; 2261c2febafcSKirill A. Shutemov p4d = p4d_alloc(mm, pgd, addr); 2262c2febafcSKirill A. Shutemov if (!p4d) 2263c2febafcSKirill A. Shutemov return -ENOMEM; 2264c2febafcSKirill A. Shutemov do { 2265c2febafcSKirill A. Shutemov next = p4d_addr_end(addr, end); 226642e4089cSAndi Kleen err = remap_pud_range(mm, p4d, addr, next, 226742e4089cSAndi Kleen pfn + (addr >> PAGE_SHIFT), prot); 226842e4089cSAndi Kleen if (err) 226942e4089cSAndi Kleen return err; 2270c2febafcSKirill A. Shutemov } while (p4d++, addr = next, addr != end); 2271c2febafcSKirill A. Shutemov return 0; 2272c2febafcSKirill A. Shutemov } 2273c2febafcSKirill A. Shutemov 227474ffa5a3SChristoph Hellwig /* 227574ffa5a3SChristoph Hellwig * Variant of remap_pfn_range that does not call track_pfn_remap. The caller 227674ffa5a3SChristoph Hellwig * must have pre-validated the caching bits of the pgprot_t. 2277bfa5bf6dSRolf Eike Beer */ 227874ffa5a3SChristoph Hellwig int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr, 22791da177e4SLinus Torvalds unsigned long pfn, unsigned long size, pgprot_t prot) 22801da177e4SLinus Torvalds { 22811da177e4SLinus Torvalds pgd_t *pgd; 22821da177e4SLinus Torvalds unsigned long next; 22832d15cab8SHugh Dickins unsigned long end = addr + PAGE_ALIGN(size); 22841da177e4SLinus Torvalds struct mm_struct *mm = vma->vm_mm; 22851da177e4SLinus Torvalds int err; 22861da177e4SLinus Torvalds 22870c4123e3SAlex Zhang if (WARN_ON_ONCE(!PAGE_ALIGNED(addr))) 22880c4123e3SAlex Zhang return -EINVAL; 22890c4123e3SAlex Zhang 22901da177e4SLinus Torvalds /* 22911da177e4SLinus Torvalds * Physically remapped pages are special. Tell the 22921da177e4SLinus Torvalds * rest of the world about it: 22931da177e4SLinus Torvalds * VM_IO tells people not to look at these pages 22941da177e4SLinus Torvalds * (accesses can have side effects). 22956aab341eSLinus Torvalds * VM_PFNMAP tells the core MM that the base pages are just 22966aab341eSLinus Torvalds * raw PFN mappings, and do not have a "struct page" associated 22976aab341eSLinus Torvalds * with them. 2298314e51b9SKonstantin Khlebnikov * VM_DONTEXPAND 2299314e51b9SKonstantin Khlebnikov * Disable vma merging and expanding with mremap(). 2300314e51b9SKonstantin Khlebnikov * VM_DONTDUMP 2301314e51b9SKonstantin Khlebnikov * Omit vma from core dump, even when VM_IO turned off. 2302fb155c16SLinus Torvalds * 2303fb155c16SLinus Torvalds * There's a horrible special case to handle copy-on-write 2304fb155c16SLinus Torvalds * behaviour that some programs depend on. We mark the "original" 2305fb155c16SLinus Torvalds * un-COW'ed pages by matching them up with "vma->vm_pgoff". 2306b3b9c293SKonstantin Khlebnikov * See vm_normal_page() for details. 23071da177e4SLinus Torvalds */ 2308b3b9c293SKonstantin Khlebnikov if (is_cow_mapping(vma->vm_flags)) { 2309b3b9c293SKonstantin Khlebnikov if (addr != vma->vm_start || end != vma->vm_end) 2310b3b9c293SKonstantin Khlebnikov return -EINVAL; 23116aab341eSLinus Torvalds vma->vm_pgoff = pfn; 2312b3b9c293SKonstantin Khlebnikov } 2313b3b9c293SKonstantin Khlebnikov 2314314e51b9SKonstantin Khlebnikov vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 23151da177e4SLinus Torvalds 23161da177e4SLinus Torvalds BUG_ON(addr >= end); 23171da177e4SLinus Torvalds pfn -= addr >> PAGE_SHIFT; 23181da177e4SLinus Torvalds pgd = pgd_offset(mm, addr); 23191da177e4SLinus Torvalds flush_cache_range(vma, addr, end); 23201da177e4SLinus Torvalds do { 23211da177e4SLinus Torvalds next = pgd_addr_end(addr, end); 2322c2febafcSKirill A. Shutemov err = remap_p4d_range(mm, pgd, addr, next, 23231da177e4SLinus Torvalds pfn + (addr >> PAGE_SHIFT), prot); 23241da177e4SLinus Torvalds if (err) 232574ffa5a3SChristoph Hellwig return err; 23261da177e4SLinus Torvalds } while (pgd++, addr = next, addr != end); 23272ab64037Svenkatesh.pallipadi@intel.com 232874ffa5a3SChristoph Hellwig return 0; 232974ffa5a3SChristoph Hellwig } 23302ab64037Svenkatesh.pallipadi@intel.com 233174ffa5a3SChristoph Hellwig /** 233274ffa5a3SChristoph Hellwig * remap_pfn_range - remap kernel memory to userspace 233374ffa5a3SChristoph Hellwig * @vma: user vma to map to 233474ffa5a3SChristoph Hellwig * @addr: target page aligned user address to start at 233574ffa5a3SChristoph Hellwig * @pfn: page frame number of kernel physical memory address 233674ffa5a3SChristoph Hellwig * @size: size of mapping area 233774ffa5a3SChristoph Hellwig * @prot: page protection flags for this mapping 233874ffa5a3SChristoph Hellwig * 233974ffa5a3SChristoph Hellwig * Note: this is only safe if the mm semaphore is held when called. 234074ffa5a3SChristoph Hellwig * 234174ffa5a3SChristoph Hellwig * Return: %0 on success, negative error code otherwise. 234274ffa5a3SChristoph Hellwig */ 234374ffa5a3SChristoph Hellwig int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 234474ffa5a3SChristoph Hellwig unsigned long pfn, unsigned long size, pgprot_t prot) 234574ffa5a3SChristoph Hellwig { 234674ffa5a3SChristoph Hellwig int err; 234774ffa5a3SChristoph Hellwig 234874ffa5a3SChristoph Hellwig err = track_pfn_remap(vma, &prot, pfn, addr, PAGE_ALIGN(size)); 234974ffa5a3SChristoph Hellwig if (err) 235074ffa5a3SChristoph Hellwig return -EINVAL; 235174ffa5a3SChristoph Hellwig 235274ffa5a3SChristoph Hellwig err = remap_pfn_range_notrack(vma, addr, pfn, size, prot); 235374ffa5a3SChristoph Hellwig if (err) 235474ffa5a3SChristoph Hellwig untrack_pfn(vma, pfn, PAGE_ALIGN(size)); 23551da177e4SLinus Torvalds return err; 23561da177e4SLinus Torvalds } 23571da177e4SLinus Torvalds EXPORT_SYMBOL(remap_pfn_range); 23581da177e4SLinus Torvalds 2359b4cbb197SLinus Torvalds /** 2360b4cbb197SLinus Torvalds * vm_iomap_memory - remap memory to userspace 2361b4cbb197SLinus Torvalds * @vma: user vma to map to 2362abd69b9eSWang Wenhu * @start: start of the physical memory to be mapped 2363b4cbb197SLinus Torvalds * @len: size of area 2364b4cbb197SLinus Torvalds * 2365b4cbb197SLinus Torvalds * This is a simplified io_remap_pfn_range() for common driver use. The 2366b4cbb197SLinus Torvalds * driver just needs to give us the physical memory range to be mapped, 2367b4cbb197SLinus Torvalds * we'll figure out the rest from the vma information. 2368b4cbb197SLinus Torvalds * 2369b4cbb197SLinus Torvalds * NOTE! Some drivers might want to tweak vma->vm_page_prot first to get 2370b4cbb197SLinus Torvalds * whatever write-combining details or similar. 2371a862f68aSMike Rapoport * 2372a862f68aSMike Rapoport * Return: %0 on success, negative error code otherwise. 2373b4cbb197SLinus Torvalds */ 2374b4cbb197SLinus Torvalds int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) 2375b4cbb197SLinus Torvalds { 2376b4cbb197SLinus Torvalds unsigned long vm_len, pfn, pages; 2377b4cbb197SLinus Torvalds 2378b4cbb197SLinus Torvalds /* Check that the physical memory area passed in looks valid */ 2379b4cbb197SLinus Torvalds if (start + len < start) 2380b4cbb197SLinus Torvalds return -EINVAL; 2381b4cbb197SLinus Torvalds /* 2382b4cbb197SLinus Torvalds * You *really* shouldn't map things that aren't page-aligned, 2383b4cbb197SLinus Torvalds * but we've historically allowed it because IO memory might 2384b4cbb197SLinus Torvalds * just have smaller alignment. 2385b4cbb197SLinus Torvalds */ 2386b4cbb197SLinus Torvalds len += start & ~PAGE_MASK; 2387b4cbb197SLinus Torvalds pfn = start >> PAGE_SHIFT; 2388b4cbb197SLinus Torvalds pages = (len + ~PAGE_MASK) >> PAGE_SHIFT; 2389b4cbb197SLinus Torvalds if (pfn + pages < pfn) 2390b4cbb197SLinus Torvalds return -EINVAL; 2391b4cbb197SLinus Torvalds 2392b4cbb197SLinus Torvalds /* We start the mapping 'vm_pgoff' pages into the area */ 2393b4cbb197SLinus Torvalds if (vma->vm_pgoff > pages) 2394b4cbb197SLinus Torvalds return -EINVAL; 2395b4cbb197SLinus Torvalds pfn += vma->vm_pgoff; 2396b4cbb197SLinus Torvalds pages -= vma->vm_pgoff; 2397b4cbb197SLinus Torvalds 2398b4cbb197SLinus Torvalds /* Can we fit all of the mapping? */ 2399b4cbb197SLinus Torvalds vm_len = vma->vm_end - vma->vm_start; 2400b4cbb197SLinus Torvalds if (vm_len >> PAGE_SHIFT > pages) 2401b4cbb197SLinus Torvalds return -EINVAL; 2402b4cbb197SLinus Torvalds 2403b4cbb197SLinus Torvalds /* Ok, let it rip */ 2404b4cbb197SLinus Torvalds return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); 2405b4cbb197SLinus Torvalds } 2406b4cbb197SLinus Torvalds EXPORT_SYMBOL(vm_iomap_memory); 2407b4cbb197SLinus Torvalds 2408aee16b3cSJeremy Fitzhardinge static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, 2409aee16b3cSJeremy Fitzhardinge unsigned long addr, unsigned long end, 2410e80d3909SJoerg Roedel pte_fn_t fn, void *data, bool create, 2411e80d3909SJoerg Roedel pgtbl_mod_mask *mask) 2412aee16b3cSJeremy Fitzhardinge { 24138abb50c7SMiaohe Lin pte_t *pte, *mapped_pte; 2414be1db475SDaniel Axtens int err = 0; 24153f649ab7SKees Cook spinlock_t *ptl; 2416aee16b3cSJeremy Fitzhardinge 2417be1db475SDaniel Axtens if (create) { 24188abb50c7SMiaohe Lin mapped_pte = pte = (mm == &init_mm) ? 2419e80d3909SJoerg Roedel pte_alloc_kernel_track(pmd, addr, mask) : 2420aee16b3cSJeremy Fitzhardinge pte_alloc_map_lock(mm, pmd, addr, &ptl); 2421aee16b3cSJeremy Fitzhardinge if (!pte) 2422aee16b3cSJeremy Fitzhardinge return -ENOMEM; 2423be1db475SDaniel Axtens } else { 24248abb50c7SMiaohe Lin mapped_pte = pte = (mm == &init_mm) ? 2425be1db475SDaniel Axtens pte_offset_kernel(pmd, addr) : 2426be1db475SDaniel Axtens pte_offset_map_lock(mm, pmd, addr, &ptl); 2427be1db475SDaniel Axtens } 2428aee16b3cSJeremy Fitzhardinge 2429aee16b3cSJeremy Fitzhardinge BUG_ON(pmd_huge(*pmd)); 2430aee16b3cSJeremy Fitzhardinge 243138e0edb1SJeremy Fitzhardinge arch_enter_lazy_mmu_mode(); 243238e0edb1SJeremy Fitzhardinge 2433eeb4a05fSChristoph Hellwig if (fn) { 2434aee16b3cSJeremy Fitzhardinge do { 2435be1db475SDaniel Axtens if (create || !pte_none(*pte)) { 24368b1e0f81SAnshuman Khandual err = fn(pte++, addr, data); 2437aee16b3cSJeremy Fitzhardinge if (err) 2438aee16b3cSJeremy Fitzhardinge break; 2439be1db475SDaniel Axtens } 2440c36987e2SDaisuke Nishimura } while (addr += PAGE_SIZE, addr != end); 2441eeb4a05fSChristoph Hellwig } 2442e80d3909SJoerg Roedel *mask |= PGTBL_PTE_MODIFIED; 2443aee16b3cSJeremy Fitzhardinge 244438e0edb1SJeremy Fitzhardinge arch_leave_lazy_mmu_mode(); 244538e0edb1SJeremy Fitzhardinge 2446aee16b3cSJeremy Fitzhardinge if (mm != &init_mm) 24478abb50c7SMiaohe Lin pte_unmap_unlock(mapped_pte, ptl); 2448aee16b3cSJeremy Fitzhardinge return err; 2449aee16b3cSJeremy Fitzhardinge } 2450aee16b3cSJeremy Fitzhardinge 2451aee16b3cSJeremy Fitzhardinge static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud, 2452aee16b3cSJeremy Fitzhardinge unsigned long addr, unsigned long end, 2453e80d3909SJoerg Roedel pte_fn_t fn, void *data, bool create, 2454e80d3909SJoerg Roedel pgtbl_mod_mask *mask) 2455aee16b3cSJeremy Fitzhardinge { 2456aee16b3cSJeremy Fitzhardinge pmd_t *pmd; 2457aee16b3cSJeremy Fitzhardinge unsigned long next; 2458be1db475SDaniel Axtens int err = 0; 2459aee16b3cSJeremy Fitzhardinge 2460ceb86879SAndi Kleen BUG_ON(pud_huge(*pud)); 2461ceb86879SAndi Kleen 2462be1db475SDaniel Axtens if (create) { 2463e80d3909SJoerg Roedel pmd = pmd_alloc_track(mm, pud, addr, mask); 2464aee16b3cSJeremy Fitzhardinge if (!pmd) 2465aee16b3cSJeremy Fitzhardinge return -ENOMEM; 2466be1db475SDaniel Axtens } else { 2467be1db475SDaniel Axtens pmd = pmd_offset(pud, addr); 2468be1db475SDaniel Axtens } 2469aee16b3cSJeremy Fitzhardinge do { 2470aee16b3cSJeremy Fitzhardinge next = pmd_addr_end(addr, end); 24710c95cba4SNicholas Piggin if (pmd_none(*pmd) && !create) 24720c95cba4SNicholas Piggin continue; 24730c95cba4SNicholas Piggin if (WARN_ON_ONCE(pmd_leaf(*pmd))) 24740c95cba4SNicholas Piggin return -EINVAL; 24750c95cba4SNicholas Piggin if (!pmd_none(*pmd) && WARN_ON_ONCE(pmd_bad(*pmd))) { 24760c95cba4SNicholas Piggin if (!create) 24770c95cba4SNicholas Piggin continue; 24780c95cba4SNicholas Piggin pmd_clear_bad(pmd); 24790c95cba4SNicholas Piggin } 24800c95cba4SNicholas Piggin err = apply_to_pte_range(mm, pmd, addr, next, 24810c95cba4SNicholas Piggin fn, data, create, mask); 2482aee16b3cSJeremy Fitzhardinge if (err) 2483aee16b3cSJeremy Fitzhardinge break; 2484aee16b3cSJeremy Fitzhardinge } while (pmd++, addr = next, addr != end); 24850c95cba4SNicholas Piggin 2486aee16b3cSJeremy Fitzhardinge return err; 2487aee16b3cSJeremy Fitzhardinge } 2488aee16b3cSJeremy Fitzhardinge 2489c2febafcSKirill A. Shutemov static int apply_to_pud_range(struct mm_struct *mm, p4d_t *p4d, 2490aee16b3cSJeremy Fitzhardinge unsigned long addr, unsigned long end, 2491e80d3909SJoerg Roedel pte_fn_t fn, void *data, bool create, 2492e80d3909SJoerg Roedel pgtbl_mod_mask *mask) 2493aee16b3cSJeremy Fitzhardinge { 2494aee16b3cSJeremy Fitzhardinge pud_t *pud; 2495aee16b3cSJeremy Fitzhardinge unsigned long next; 2496be1db475SDaniel Axtens int err = 0; 2497aee16b3cSJeremy Fitzhardinge 2498be1db475SDaniel Axtens if (create) { 2499e80d3909SJoerg Roedel pud = pud_alloc_track(mm, p4d, addr, mask); 2500aee16b3cSJeremy Fitzhardinge if (!pud) 2501aee16b3cSJeremy Fitzhardinge return -ENOMEM; 2502be1db475SDaniel Axtens } else { 2503be1db475SDaniel Axtens pud = pud_offset(p4d, addr); 2504be1db475SDaniel Axtens } 2505aee16b3cSJeremy Fitzhardinge do { 2506aee16b3cSJeremy Fitzhardinge next = pud_addr_end(addr, end); 25070c95cba4SNicholas Piggin if (pud_none(*pud) && !create) 25080c95cba4SNicholas Piggin continue; 25090c95cba4SNicholas Piggin if (WARN_ON_ONCE(pud_leaf(*pud))) 25100c95cba4SNicholas Piggin return -EINVAL; 25110c95cba4SNicholas Piggin if (!pud_none(*pud) && WARN_ON_ONCE(pud_bad(*pud))) { 25120c95cba4SNicholas Piggin if (!create) 25130c95cba4SNicholas Piggin continue; 25140c95cba4SNicholas Piggin pud_clear_bad(pud); 25150c95cba4SNicholas Piggin } 25160c95cba4SNicholas Piggin err = apply_to_pmd_range(mm, pud, addr, next, 25170c95cba4SNicholas Piggin fn, data, create, mask); 2518aee16b3cSJeremy Fitzhardinge if (err) 2519aee16b3cSJeremy Fitzhardinge break; 2520aee16b3cSJeremy Fitzhardinge } while (pud++, addr = next, addr != end); 25210c95cba4SNicholas Piggin 2522aee16b3cSJeremy Fitzhardinge return err; 2523aee16b3cSJeremy Fitzhardinge } 2524aee16b3cSJeremy Fitzhardinge 2525c2febafcSKirill A. Shutemov static int apply_to_p4d_range(struct mm_struct *mm, pgd_t *pgd, 2526c2febafcSKirill A. Shutemov unsigned long addr, unsigned long end, 2527e80d3909SJoerg Roedel pte_fn_t fn, void *data, bool create, 2528e80d3909SJoerg Roedel pgtbl_mod_mask *mask) 2529c2febafcSKirill A. Shutemov { 2530c2febafcSKirill A. Shutemov p4d_t *p4d; 2531c2febafcSKirill A. Shutemov unsigned long next; 2532be1db475SDaniel Axtens int err = 0; 2533c2febafcSKirill A. Shutemov 2534be1db475SDaniel Axtens if (create) { 2535e80d3909SJoerg Roedel p4d = p4d_alloc_track(mm, pgd, addr, mask); 2536c2febafcSKirill A. Shutemov if (!p4d) 2537c2febafcSKirill A. Shutemov return -ENOMEM; 2538be1db475SDaniel Axtens } else { 2539be1db475SDaniel Axtens p4d = p4d_offset(pgd, addr); 2540be1db475SDaniel Axtens } 2541c2febafcSKirill A. Shutemov do { 2542c2febafcSKirill A. Shutemov next = p4d_addr_end(addr, end); 25430c95cba4SNicholas Piggin if (p4d_none(*p4d) && !create) 25440c95cba4SNicholas Piggin continue; 25450c95cba4SNicholas Piggin if (WARN_ON_ONCE(p4d_leaf(*p4d))) 25460c95cba4SNicholas Piggin return -EINVAL; 25470c95cba4SNicholas Piggin if (!p4d_none(*p4d) && WARN_ON_ONCE(p4d_bad(*p4d))) { 25480c95cba4SNicholas Piggin if (!create) 25490c95cba4SNicholas Piggin continue; 25500c95cba4SNicholas Piggin p4d_clear_bad(p4d); 25510c95cba4SNicholas Piggin } 25520c95cba4SNicholas Piggin err = apply_to_pud_range(mm, p4d, addr, next, 25530c95cba4SNicholas Piggin fn, data, create, mask); 2554c2febafcSKirill A. Shutemov if (err) 2555c2febafcSKirill A. Shutemov break; 2556c2febafcSKirill A. Shutemov } while (p4d++, addr = next, addr != end); 25570c95cba4SNicholas Piggin 2558c2febafcSKirill A. Shutemov return err; 2559c2febafcSKirill A. Shutemov } 2560c2febafcSKirill A. Shutemov 2561be1db475SDaniel Axtens static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr, 2562be1db475SDaniel Axtens unsigned long size, pte_fn_t fn, 2563be1db475SDaniel Axtens void *data, bool create) 2564be1db475SDaniel Axtens { 2565be1db475SDaniel Axtens pgd_t *pgd; 2566e80d3909SJoerg Roedel unsigned long start = addr, next; 2567be1db475SDaniel Axtens unsigned long end = addr + size; 2568e80d3909SJoerg Roedel pgtbl_mod_mask mask = 0; 2569be1db475SDaniel Axtens int err = 0; 2570be1db475SDaniel Axtens 2571be1db475SDaniel Axtens if (WARN_ON(addr >= end)) 2572be1db475SDaniel Axtens return -EINVAL; 2573be1db475SDaniel Axtens 2574be1db475SDaniel Axtens pgd = pgd_offset(mm, addr); 2575be1db475SDaniel Axtens do { 2576be1db475SDaniel Axtens next = pgd_addr_end(addr, end); 25770c95cba4SNicholas Piggin if (pgd_none(*pgd) && !create) 2578be1db475SDaniel Axtens continue; 25790c95cba4SNicholas Piggin if (WARN_ON_ONCE(pgd_leaf(*pgd))) 25800c95cba4SNicholas Piggin return -EINVAL; 25810c95cba4SNicholas Piggin if (!pgd_none(*pgd) && WARN_ON_ONCE(pgd_bad(*pgd))) { 25820c95cba4SNicholas Piggin if (!create) 25830c95cba4SNicholas Piggin continue; 25840c95cba4SNicholas Piggin pgd_clear_bad(pgd); 25850c95cba4SNicholas Piggin } 25860c95cba4SNicholas Piggin err = apply_to_p4d_range(mm, pgd, addr, next, 25870c95cba4SNicholas Piggin fn, data, create, &mask); 2588be1db475SDaniel Axtens if (err) 2589be1db475SDaniel Axtens break; 2590be1db475SDaniel Axtens } while (pgd++, addr = next, addr != end); 2591be1db475SDaniel Axtens 2592e80d3909SJoerg Roedel if (mask & ARCH_PAGE_TABLE_SYNC_MASK) 2593e80d3909SJoerg Roedel arch_sync_kernel_mappings(start, start + size); 2594e80d3909SJoerg Roedel 2595be1db475SDaniel Axtens return err; 2596be1db475SDaniel Axtens } 2597be1db475SDaniel Axtens 2598aee16b3cSJeremy Fitzhardinge /* 2599aee16b3cSJeremy Fitzhardinge * Scan a region of virtual memory, filling in page tables as necessary 2600aee16b3cSJeremy Fitzhardinge * and calling a provided function on each leaf page table. 2601aee16b3cSJeremy Fitzhardinge */ 2602aee16b3cSJeremy Fitzhardinge int apply_to_page_range(struct mm_struct *mm, unsigned long addr, 2603aee16b3cSJeremy Fitzhardinge unsigned long size, pte_fn_t fn, void *data) 2604aee16b3cSJeremy Fitzhardinge { 2605be1db475SDaniel Axtens return __apply_to_page_range(mm, addr, size, fn, data, true); 2606aee16b3cSJeremy Fitzhardinge } 2607aee16b3cSJeremy Fitzhardinge EXPORT_SYMBOL_GPL(apply_to_page_range); 2608aee16b3cSJeremy Fitzhardinge 26091da177e4SLinus Torvalds /* 2610be1db475SDaniel Axtens * Scan a region of virtual memory, calling a provided function on 2611be1db475SDaniel Axtens * each leaf page table where it exists. 2612be1db475SDaniel Axtens * 2613be1db475SDaniel Axtens * Unlike apply_to_page_range, this does _not_ fill in page tables 2614be1db475SDaniel Axtens * where they are absent. 2615be1db475SDaniel Axtens */ 2616be1db475SDaniel Axtens int apply_to_existing_page_range(struct mm_struct *mm, unsigned long addr, 2617be1db475SDaniel Axtens unsigned long size, pte_fn_t fn, void *data) 2618be1db475SDaniel Axtens { 2619be1db475SDaniel Axtens return __apply_to_page_range(mm, addr, size, fn, data, false); 2620be1db475SDaniel Axtens } 2621be1db475SDaniel Axtens EXPORT_SYMBOL_GPL(apply_to_existing_page_range); 2622be1db475SDaniel Axtens 2623be1db475SDaniel Axtens /* 26249b4bdd2fSKirill A. Shutemov * handle_pte_fault chooses page fault handler according to an entry which was 26259b4bdd2fSKirill A. Shutemov * read non-atomically. Before making any commitment, on those architectures 26269b4bdd2fSKirill A. Shutemov * or configurations (e.g. i386 with PAE) which might give a mix of unmatched 26279b4bdd2fSKirill A. Shutemov * parts, do_swap_page must check under lock before unmapping the pte and 26289b4bdd2fSKirill A. Shutemov * proceeding (but do_wp_page is only called after already making such a check; 2629a335b2e1SRyota Ozaki * and do_anonymous_page can safely check later on). 26308f4e2101SHugh Dickins */ 26314c21e2f2SHugh Dickins static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd, 26328f4e2101SHugh Dickins pte_t *page_table, pte_t orig_pte) 26338f4e2101SHugh Dickins { 26348f4e2101SHugh Dickins int same = 1; 2635923717cbSThomas Gleixner #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPTION) 26368f4e2101SHugh Dickins if (sizeof(pte_t) > sizeof(unsigned long)) { 26374c21e2f2SHugh Dickins spinlock_t *ptl = pte_lockptr(mm, pmd); 26384c21e2f2SHugh Dickins spin_lock(ptl); 26398f4e2101SHugh Dickins same = pte_same(*page_table, orig_pte); 26404c21e2f2SHugh Dickins spin_unlock(ptl); 26418f4e2101SHugh Dickins } 26428f4e2101SHugh Dickins #endif 26438f4e2101SHugh Dickins pte_unmap(page_table); 26448f4e2101SHugh Dickins return same; 26458f4e2101SHugh Dickins } 26468f4e2101SHugh Dickins 264783d116c5SJia He static inline bool cow_user_page(struct page *dst, struct page *src, 264883d116c5SJia He struct vm_fault *vmf) 26496aab341eSLinus Torvalds { 265083d116c5SJia He bool ret; 265183d116c5SJia He void *kaddr; 265283d116c5SJia He void __user *uaddr; 2653c3e5ea6eSKirill A. Shutemov bool locked = false; 265483d116c5SJia He struct vm_area_struct *vma = vmf->vma; 265583d116c5SJia He struct mm_struct *mm = vma->vm_mm; 265683d116c5SJia He unsigned long addr = vmf->address; 265783d116c5SJia He 265883d116c5SJia He if (likely(src)) { 265983d116c5SJia He copy_user_highpage(dst, src, addr, vma); 266083d116c5SJia He return true; 266183d116c5SJia He } 266283d116c5SJia He 26636aab341eSLinus Torvalds /* 26646aab341eSLinus Torvalds * If the source page was a PFN mapping, we don't have 26656aab341eSLinus Torvalds * a "struct page" for it. We do a best-effort copy by 26666aab341eSLinus Torvalds * just copying from the original user address. If that 26676aab341eSLinus Torvalds * fails, we just zero-fill it. Live with it. 26686aab341eSLinus Torvalds */ 266983d116c5SJia He kaddr = kmap_atomic(dst); 267083d116c5SJia He uaddr = (void __user *)(addr & PAGE_MASK); 267183d116c5SJia He 267283d116c5SJia He /* 267383d116c5SJia He * On architectures with software "accessed" bits, we would 267483d116c5SJia He * take a double page fault, so mark it accessed here. 267583d116c5SJia He */ 2676c3e5ea6eSKirill A. Shutemov if (arch_faults_on_old_pte() && !pte_young(vmf->orig_pte)) { 267783d116c5SJia He pte_t entry; 267883d116c5SJia He 267983d116c5SJia He vmf->pte = pte_offset_map_lock(mm, vmf->pmd, addr, &vmf->ptl); 2680c3e5ea6eSKirill A. Shutemov locked = true; 268183d116c5SJia He if (!likely(pte_same(*vmf->pte, vmf->orig_pte))) { 268283d116c5SJia He /* 268383d116c5SJia He * Other thread has already handled the fault 26847df67697SBibo Mao * and update local tlb only 268583d116c5SJia He */ 26867df67697SBibo Mao update_mmu_tlb(vma, addr, vmf->pte); 268783d116c5SJia He ret = false; 268883d116c5SJia He goto pte_unlock; 268983d116c5SJia He } 269083d116c5SJia He 269183d116c5SJia He entry = pte_mkyoung(vmf->orig_pte); 269283d116c5SJia He if (ptep_set_access_flags(vma, addr, vmf->pte, entry, 0)) 269383d116c5SJia He update_mmu_cache(vma, addr, vmf->pte); 269483d116c5SJia He } 26955d2a2dbbSLinus Torvalds 26965d2a2dbbSLinus Torvalds /* 26975d2a2dbbSLinus Torvalds * This really shouldn't fail, because the page is there 26985d2a2dbbSLinus Torvalds * in the page tables. But it might just be unreadable, 26995d2a2dbbSLinus Torvalds * in which case we just give up and fill the result with 27005d2a2dbbSLinus Torvalds * zeroes. 27015d2a2dbbSLinus Torvalds */ 270283d116c5SJia He if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE)) { 2703c3e5ea6eSKirill A. Shutemov if (locked) 2704c3e5ea6eSKirill A. Shutemov goto warn; 2705c3e5ea6eSKirill A. Shutemov 2706c3e5ea6eSKirill A. Shutemov /* Re-validate under PTL if the page is still mapped */ 2707c3e5ea6eSKirill A. Shutemov vmf->pte = pte_offset_map_lock(mm, vmf->pmd, addr, &vmf->ptl); 2708c3e5ea6eSKirill A. Shutemov locked = true; 2709c3e5ea6eSKirill A. Shutemov if (!likely(pte_same(*vmf->pte, vmf->orig_pte))) { 27107df67697SBibo Mao /* The PTE changed under us, update local tlb */ 27117df67697SBibo Mao update_mmu_tlb(vma, addr, vmf->pte); 2712c3e5ea6eSKirill A. Shutemov ret = false; 2713c3e5ea6eSKirill A. Shutemov goto pte_unlock; 2714c3e5ea6eSKirill A. Shutemov } 2715c3e5ea6eSKirill A. Shutemov 2716c3e5ea6eSKirill A. Shutemov /* 2717985ba004SEthon Paul * The same page can be mapped back since last copy attempt. 2718c3e5ea6eSKirill A. Shutemov * Try to copy again under PTL. 2719c3e5ea6eSKirill A. Shutemov */ 2720c3e5ea6eSKirill A. Shutemov if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE)) { 272183d116c5SJia He /* 272283d116c5SJia He * Give a warn in case there can be some obscure 272383d116c5SJia He * use-case 272483d116c5SJia He */ 2725c3e5ea6eSKirill A. Shutemov warn: 272683d116c5SJia He WARN_ON_ONCE(1); 27273ecb01dfSJan Beulich clear_page(kaddr); 272883d116c5SJia He } 2729c3e5ea6eSKirill A. Shutemov } 273083d116c5SJia He 273183d116c5SJia He ret = true; 273283d116c5SJia He 273383d116c5SJia He pte_unlock: 2734c3e5ea6eSKirill A. Shutemov if (locked) 273583d116c5SJia He pte_unmap_unlock(vmf->pte, vmf->ptl); 27369b04c5feSCong Wang kunmap_atomic(kaddr); 2737c4ec7b0dSDmitriy Monakhov flush_dcache_page(dst); 273883d116c5SJia He 273983d116c5SJia He return ret; 27406aab341eSLinus Torvalds } 27416aab341eSLinus Torvalds 2742c20cd45eSMichal Hocko static gfp_t __get_fault_gfp_mask(struct vm_area_struct *vma) 2743c20cd45eSMichal Hocko { 2744c20cd45eSMichal Hocko struct file *vm_file = vma->vm_file; 2745c20cd45eSMichal Hocko 2746c20cd45eSMichal Hocko if (vm_file) 2747c20cd45eSMichal Hocko return mapping_gfp_mask(vm_file->f_mapping) | __GFP_FS | __GFP_IO; 2748c20cd45eSMichal Hocko 2749c20cd45eSMichal Hocko /* 2750c20cd45eSMichal Hocko * Special mappings (e.g. VDSO) do not have any file so fake 2751c20cd45eSMichal Hocko * a default GFP_KERNEL for them. 2752c20cd45eSMichal Hocko */ 2753c20cd45eSMichal Hocko return GFP_KERNEL; 2754c20cd45eSMichal Hocko } 2755c20cd45eSMichal Hocko 27561da177e4SLinus Torvalds /* 2757fb09a464SKirill A. Shutemov * Notify the address space that the page is about to become writable so that 2758fb09a464SKirill A. Shutemov * it can prohibit this or wait for the page to get into an appropriate state. 2759fb09a464SKirill A. Shutemov * 2760fb09a464SKirill A. Shutemov * We do this without the lock held, so that it can sleep if it needs to. 2761fb09a464SKirill A. Shutemov */ 27622b740303SSouptick Joarder static vm_fault_t do_page_mkwrite(struct vm_fault *vmf) 2763fb09a464SKirill A. Shutemov { 27642b740303SSouptick Joarder vm_fault_t ret; 276538b8cb7fSJan Kara struct page *page = vmf->page; 276638b8cb7fSJan Kara unsigned int old_flags = vmf->flags; 2767fb09a464SKirill A. Shutemov 276838b8cb7fSJan Kara vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; 2769fb09a464SKirill A. Shutemov 2770dc617f29SDarrick J. Wong if (vmf->vma->vm_file && 2771dc617f29SDarrick J. Wong IS_SWAPFILE(vmf->vma->vm_file->f_mapping->host)) 2772dc617f29SDarrick J. Wong return VM_FAULT_SIGBUS; 2773dc617f29SDarrick J. Wong 277411bac800SDave Jiang ret = vmf->vma->vm_ops->page_mkwrite(vmf); 277538b8cb7fSJan Kara /* Restore original flags so that caller is not surprised */ 277638b8cb7fSJan Kara vmf->flags = old_flags; 2777fb09a464SKirill A. Shutemov if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) 2778fb09a464SKirill A. Shutemov return ret; 2779fb09a464SKirill A. Shutemov if (unlikely(!(ret & VM_FAULT_LOCKED))) { 2780fb09a464SKirill A. Shutemov lock_page(page); 2781fb09a464SKirill A. Shutemov if (!page->mapping) { 2782fb09a464SKirill A. Shutemov unlock_page(page); 2783fb09a464SKirill A. Shutemov return 0; /* retry */ 2784fb09a464SKirill A. Shutemov } 2785fb09a464SKirill A. Shutemov ret |= VM_FAULT_LOCKED; 2786fb09a464SKirill A. Shutemov } else 2787fb09a464SKirill A. Shutemov VM_BUG_ON_PAGE(!PageLocked(page), page); 2788fb09a464SKirill A. Shutemov return ret; 2789fb09a464SKirill A. Shutemov } 2790fb09a464SKirill A. Shutemov 2791fb09a464SKirill A. Shutemov /* 279297ba0c2bSJan Kara * Handle dirtying of a page in shared file mapping on a write fault. 27934e047f89SShachar Raindel * 279497ba0c2bSJan Kara * The function expects the page to be locked and unlocks it. 27954e047f89SShachar Raindel */ 279689b15332SJohannes Weiner static vm_fault_t fault_dirty_shared_page(struct vm_fault *vmf) 27974e047f89SShachar Raindel { 279889b15332SJohannes Weiner struct vm_area_struct *vma = vmf->vma; 27994e047f89SShachar Raindel struct address_space *mapping; 280089b15332SJohannes Weiner struct page *page = vmf->page; 280197ba0c2bSJan Kara bool dirtied; 280297ba0c2bSJan Kara bool page_mkwrite = vma->vm_ops && vma->vm_ops->page_mkwrite; 28034e047f89SShachar Raindel 28044e047f89SShachar Raindel dirtied = set_page_dirty(page); 28054e047f89SShachar Raindel VM_BUG_ON_PAGE(PageAnon(page), page); 280697ba0c2bSJan Kara /* 280797ba0c2bSJan Kara * Take a local copy of the address_space - page.mapping may be zeroed 280897ba0c2bSJan Kara * by truncate after unlock_page(). The address_space itself remains 280997ba0c2bSJan Kara * pinned by vma->vm_file's reference. We rely on unlock_page()'s 281097ba0c2bSJan Kara * release semantics to prevent the compiler from undoing this copying. 281197ba0c2bSJan Kara */ 281297ba0c2bSJan Kara mapping = page_rmapping(page); 28134e047f89SShachar Raindel unlock_page(page); 28144e047f89SShachar Raindel 28154e047f89SShachar Raindel if (!page_mkwrite) 28164e047f89SShachar Raindel file_update_time(vma->vm_file); 281789b15332SJohannes Weiner 281889b15332SJohannes Weiner /* 281989b15332SJohannes Weiner * Throttle page dirtying rate down to writeback speed. 282089b15332SJohannes Weiner * 282189b15332SJohannes Weiner * mapping may be NULL here because some device drivers do not 282289b15332SJohannes Weiner * set page.mapping but still dirty their pages 282389b15332SJohannes Weiner * 2824c1e8d7c6SMichel Lespinasse * Drop the mmap_lock before waiting on IO, if we can. The file 282589b15332SJohannes Weiner * is pinning the mapping, as per above. 282689b15332SJohannes Weiner */ 282789b15332SJohannes Weiner if ((dirtied || page_mkwrite) && mapping) { 282889b15332SJohannes Weiner struct file *fpin; 282989b15332SJohannes Weiner 283089b15332SJohannes Weiner fpin = maybe_unlock_mmap_for_io(vmf, NULL); 283189b15332SJohannes Weiner balance_dirty_pages_ratelimited(mapping); 283289b15332SJohannes Weiner if (fpin) { 283389b15332SJohannes Weiner fput(fpin); 283489b15332SJohannes Weiner return VM_FAULT_RETRY; 283589b15332SJohannes Weiner } 283689b15332SJohannes Weiner } 283789b15332SJohannes Weiner 283889b15332SJohannes Weiner return 0; 28394e047f89SShachar Raindel } 28404e047f89SShachar Raindel 284197ba0c2bSJan Kara /* 28424e047f89SShachar Raindel * Handle write page faults for pages that can be reused in the current vma 28434e047f89SShachar Raindel * 28444e047f89SShachar Raindel * This can happen either due to the mapping being with the VM_SHARED flag, 28454e047f89SShachar Raindel * or due to us being the last reference standing to the page. In either 28464e047f89SShachar Raindel * case, all we need to do here is to mark the page as writable and update 28474e047f89SShachar Raindel * any related book-keeping. 28484e047f89SShachar Raindel */ 2849997dd98dSJan Kara static inline void wp_page_reuse(struct vm_fault *vmf) 285082b0f8c3SJan Kara __releases(vmf->ptl) 28514e047f89SShachar Raindel { 285282b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 2853a41b70d6SJan Kara struct page *page = vmf->page; 28544e047f89SShachar Raindel pte_t entry; 28554e047f89SShachar Raindel /* 28564e047f89SShachar Raindel * Clear the pages cpupid information as the existing 28574e047f89SShachar Raindel * information potentially belongs to a now completely 28584e047f89SShachar Raindel * unrelated process. 28594e047f89SShachar Raindel */ 28604e047f89SShachar Raindel if (page) 28614e047f89SShachar Raindel page_cpupid_xchg_last(page, (1 << LAST_CPUPID_SHIFT) - 1); 28624e047f89SShachar Raindel 28632994302bSJan Kara flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); 28642994302bSJan Kara entry = pte_mkyoung(vmf->orig_pte); 28654e047f89SShachar Raindel entry = maybe_mkwrite(pte_mkdirty(entry), vma); 286682b0f8c3SJan Kara if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1)) 286782b0f8c3SJan Kara update_mmu_cache(vma, vmf->address, vmf->pte); 286882b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 2869798a6b87SPeter Xu count_vm_event(PGREUSE); 28704e047f89SShachar Raindel } 28714e047f89SShachar Raindel 28724e047f89SShachar Raindel /* 28732f38ab2cSShachar Raindel * Handle the case of a page which we actually need to copy to a new page. 28742f38ab2cSShachar Raindel * 2875c1e8d7c6SMichel Lespinasse * Called with mmap_lock locked and the old page referenced, but 28762f38ab2cSShachar Raindel * without the ptl held. 28772f38ab2cSShachar Raindel * 28782f38ab2cSShachar Raindel * High level logic flow: 28792f38ab2cSShachar Raindel * 28802f38ab2cSShachar Raindel * - Allocate a page, copy the content of the old page to the new one. 28812f38ab2cSShachar Raindel * - Handle book keeping and accounting - cgroups, mmu-notifiers, etc. 28822f38ab2cSShachar Raindel * - Take the PTL. If the pte changed, bail out and release the allocated page 28832f38ab2cSShachar Raindel * - If the pte is still the way we remember it, update the page table and all 28842f38ab2cSShachar Raindel * relevant references. This includes dropping the reference the page-table 28852f38ab2cSShachar Raindel * held to the old page, as well as updating the rmap. 28862f38ab2cSShachar Raindel * - In any case, unlock the PTL and drop the reference we took to the old page. 28872f38ab2cSShachar Raindel */ 28882b740303SSouptick Joarder static vm_fault_t wp_page_copy(struct vm_fault *vmf) 28892f38ab2cSShachar Raindel { 289082b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 2891bae473a4SKirill A. Shutemov struct mm_struct *mm = vma->vm_mm; 2892a41b70d6SJan Kara struct page *old_page = vmf->page; 28932f38ab2cSShachar Raindel struct page *new_page = NULL; 28942f38ab2cSShachar Raindel pte_t entry; 28952f38ab2cSShachar Raindel int page_copied = 0; 2896ac46d4f3SJérôme Glisse struct mmu_notifier_range range; 28972f38ab2cSShachar Raindel 28982f38ab2cSShachar Raindel if (unlikely(anon_vma_prepare(vma))) 28992f38ab2cSShachar Raindel goto oom; 29002f38ab2cSShachar Raindel 29012994302bSJan Kara if (is_zero_pfn(pte_pfn(vmf->orig_pte))) { 290282b0f8c3SJan Kara new_page = alloc_zeroed_user_highpage_movable(vma, 290382b0f8c3SJan Kara vmf->address); 29042f38ab2cSShachar Raindel if (!new_page) 29052f38ab2cSShachar Raindel goto oom; 29062f38ab2cSShachar Raindel } else { 2907bae473a4SKirill A. Shutemov new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, 290882b0f8c3SJan Kara vmf->address); 29092f38ab2cSShachar Raindel if (!new_page) 29102f38ab2cSShachar Raindel goto oom; 291183d116c5SJia He 291283d116c5SJia He if (!cow_user_page(new_page, old_page, vmf)) { 291383d116c5SJia He /* 291483d116c5SJia He * COW failed, if the fault was solved by other, 291583d116c5SJia He * it's fine. If not, userspace would re-fault on 291683d116c5SJia He * the same address and we will handle the fault 291783d116c5SJia He * from the second attempt. 291883d116c5SJia He */ 291983d116c5SJia He put_page(new_page); 292083d116c5SJia He if (old_page) 292183d116c5SJia He put_page(old_page); 292283d116c5SJia He return 0; 292383d116c5SJia He } 29242f38ab2cSShachar Raindel } 29252f38ab2cSShachar Raindel 2926d9eb1ea2SJohannes Weiner if (mem_cgroup_charge(new_page, mm, GFP_KERNEL)) 29272f38ab2cSShachar Raindel goto oom_free_new; 29289d82c694SJohannes Weiner cgroup_throttle_swaprate(new_page, GFP_KERNEL); 29292f38ab2cSShachar Raindel 2930eb3c24f3SMel Gorman __SetPageUptodate(new_page); 2931eb3c24f3SMel Gorman 29327269f999SJérôme Glisse mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, 29336f4f13e8SJérôme Glisse vmf->address & PAGE_MASK, 2934ac46d4f3SJérôme Glisse (vmf->address & PAGE_MASK) + PAGE_SIZE); 2935ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(&range); 29362f38ab2cSShachar Raindel 29372f38ab2cSShachar Raindel /* 29382f38ab2cSShachar Raindel * Re-check the pte - we dropped the lock 29392f38ab2cSShachar Raindel */ 294082b0f8c3SJan Kara vmf->pte = pte_offset_map_lock(mm, vmf->pmd, vmf->address, &vmf->ptl); 29412994302bSJan Kara if (likely(pte_same(*vmf->pte, vmf->orig_pte))) { 29422f38ab2cSShachar Raindel if (old_page) { 29432f38ab2cSShachar Raindel if (!PageAnon(old_page)) { 2944eca56ff9SJerome Marchand dec_mm_counter_fast(mm, 2945eca56ff9SJerome Marchand mm_counter_file(old_page)); 29462f38ab2cSShachar Raindel inc_mm_counter_fast(mm, MM_ANONPAGES); 29472f38ab2cSShachar Raindel } 29482f38ab2cSShachar Raindel } else { 29492f38ab2cSShachar Raindel inc_mm_counter_fast(mm, MM_ANONPAGES); 29502f38ab2cSShachar Raindel } 29512994302bSJan Kara flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte)); 29522f38ab2cSShachar Raindel entry = mk_pte(new_page, vma->vm_page_prot); 295350c25ee9SThomas Bogendoerfer entry = pte_sw_mkyoung(entry); 29542f38ab2cSShachar Raindel entry = maybe_mkwrite(pte_mkdirty(entry), vma); 2955111fe718SNicholas Piggin 29562f38ab2cSShachar Raindel /* 29572f38ab2cSShachar Raindel * Clear the pte entry and flush it first, before updating the 2958111fe718SNicholas Piggin * pte with the new entry, to keep TLBs on different CPUs in 2959111fe718SNicholas Piggin * sync. This code used to set the new PTE then flush TLBs, but 2960111fe718SNicholas Piggin * that left a window where the new PTE could be loaded into 2961111fe718SNicholas Piggin * some TLBs while the old PTE remains in others. 29622f38ab2cSShachar Raindel */ 296382b0f8c3SJan Kara ptep_clear_flush_notify(vma, vmf->address, vmf->pte); 296482b0f8c3SJan Kara page_add_new_anon_rmap(new_page, vma, vmf->address, false); 2965b518154eSJoonsoo Kim lru_cache_add_inactive_or_unevictable(new_page, vma); 29662f38ab2cSShachar Raindel /* 29672f38ab2cSShachar Raindel * We call the notify macro here because, when using secondary 29682f38ab2cSShachar Raindel * mmu page tables (such as kvm shadow page tables), we want the 29692f38ab2cSShachar Raindel * new page to be mapped directly into the secondary page table. 29702f38ab2cSShachar Raindel */ 297182b0f8c3SJan Kara set_pte_at_notify(mm, vmf->address, vmf->pte, entry); 297282b0f8c3SJan Kara update_mmu_cache(vma, vmf->address, vmf->pte); 29732f38ab2cSShachar Raindel if (old_page) { 29742f38ab2cSShachar Raindel /* 29752f38ab2cSShachar Raindel * Only after switching the pte to the new page may 29762f38ab2cSShachar Raindel * we remove the mapcount here. Otherwise another 29772f38ab2cSShachar Raindel * process may come and find the rmap count decremented 29782f38ab2cSShachar Raindel * before the pte is switched to the new page, and 29792f38ab2cSShachar Raindel * "reuse" the old page writing into it while our pte 29802f38ab2cSShachar Raindel * here still points into it and can be read by other 29812f38ab2cSShachar Raindel * threads. 29822f38ab2cSShachar Raindel * 29832f38ab2cSShachar Raindel * The critical issue is to order this 29842f38ab2cSShachar Raindel * page_remove_rmap with the ptp_clear_flush above. 29852f38ab2cSShachar Raindel * Those stores are ordered by (if nothing else,) 29862f38ab2cSShachar Raindel * the barrier present in the atomic_add_negative 29872f38ab2cSShachar Raindel * in page_remove_rmap. 29882f38ab2cSShachar Raindel * 29892f38ab2cSShachar Raindel * Then the TLB flush in ptep_clear_flush ensures that 29902f38ab2cSShachar Raindel * no process can access the old page before the 29912f38ab2cSShachar Raindel * decremented mapcount is visible. And the old page 29922f38ab2cSShachar Raindel * cannot be reused until after the decremented 29932f38ab2cSShachar Raindel * mapcount is visible. So transitively, TLBs to 29942f38ab2cSShachar Raindel * old page will be flushed before it can be reused. 29952f38ab2cSShachar Raindel */ 2996d281ee61SKirill A. Shutemov page_remove_rmap(old_page, false); 29972f38ab2cSShachar Raindel } 29982f38ab2cSShachar Raindel 29992f38ab2cSShachar Raindel /* Free the old page.. */ 30002f38ab2cSShachar Raindel new_page = old_page; 30012f38ab2cSShachar Raindel page_copied = 1; 30022f38ab2cSShachar Raindel } else { 30037df67697SBibo Mao update_mmu_tlb(vma, vmf->address, vmf->pte); 30042f38ab2cSShachar Raindel } 30052f38ab2cSShachar Raindel 30062f38ab2cSShachar Raindel if (new_page) 300709cbfeafSKirill A. Shutemov put_page(new_page); 30082f38ab2cSShachar Raindel 300982b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 30104645b9feSJérôme Glisse /* 30114645b9feSJérôme Glisse * No need to double call mmu_notifier->invalidate_range() callback as 30124645b9feSJérôme Glisse * the above ptep_clear_flush_notify() did already call it. 30134645b9feSJérôme Glisse */ 3014ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_only_end(&range); 30152f38ab2cSShachar Raindel if (old_page) { 30162f38ab2cSShachar Raindel /* 30172f38ab2cSShachar Raindel * Don't let another task, with possibly unlocked vma, 30182f38ab2cSShachar Raindel * keep the mlocked page. 30192f38ab2cSShachar Raindel */ 30202f38ab2cSShachar Raindel if (page_copied && (vma->vm_flags & VM_LOCKED)) { 30212f38ab2cSShachar Raindel lock_page(old_page); /* LRU manipulation */ 3022e90309c9SKirill A. Shutemov if (PageMlocked(old_page)) 30232f38ab2cSShachar Raindel munlock_vma_page(old_page); 30242f38ab2cSShachar Raindel unlock_page(old_page); 30252f38ab2cSShachar Raindel } 302609cbfeafSKirill A. Shutemov put_page(old_page); 30272f38ab2cSShachar Raindel } 30282f38ab2cSShachar Raindel return page_copied ? VM_FAULT_WRITE : 0; 30292f38ab2cSShachar Raindel oom_free_new: 303009cbfeafSKirill A. Shutemov put_page(new_page); 30312f38ab2cSShachar Raindel oom: 30322f38ab2cSShachar Raindel if (old_page) 303309cbfeafSKirill A. Shutemov put_page(old_page); 30342f38ab2cSShachar Raindel return VM_FAULT_OOM; 30352f38ab2cSShachar Raindel } 30362f38ab2cSShachar Raindel 303766a6197cSJan Kara /** 303866a6197cSJan Kara * finish_mkwrite_fault - finish page fault for a shared mapping, making PTE 303966a6197cSJan Kara * writeable once the page is prepared 304066a6197cSJan Kara * 304166a6197cSJan Kara * @vmf: structure describing the fault 304266a6197cSJan Kara * 304366a6197cSJan Kara * This function handles all that is needed to finish a write page fault in a 304466a6197cSJan Kara * shared mapping due to PTE being read-only once the mapped page is prepared. 3045a862f68aSMike Rapoport * It handles locking of PTE and modifying it. 304666a6197cSJan Kara * 304766a6197cSJan Kara * The function expects the page to be locked or other protection against 304866a6197cSJan Kara * concurrent faults / writeback (such as DAX radix tree locks). 3049a862f68aSMike Rapoport * 3050a862f68aSMike Rapoport * Return: %VM_FAULT_WRITE on success, %0 when PTE got changed before 3051a862f68aSMike Rapoport * we acquired PTE lock. 305266a6197cSJan Kara */ 30532b740303SSouptick Joarder vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf) 305466a6197cSJan Kara { 305566a6197cSJan Kara WARN_ON_ONCE(!(vmf->vma->vm_flags & VM_SHARED)); 305666a6197cSJan Kara vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, vmf->pmd, vmf->address, 305766a6197cSJan Kara &vmf->ptl); 305866a6197cSJan Kara /* 305966a6197cSJan Kara * We might have raced with another page fault while we released the 306066a6197cSJan Kara * pte_offset_map_lock. 306166a6197cSJan Kara */ 306266a6197cSJan Kara if (!pte_same(*vmf->pte, vmf->orig_pte)) { 30637df67697SBibo Mao update_mmu_tlb(vmf->vma, vmf->address, vmf->pte); 306466a6197cSJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 3065a19e2553SJan Kara return VM_FAULT_NOPAGE; 306666a6197cSJan Kara } 306766a6197cSJan Kara wp_page_reuse(vmf); 3068a19e2553SJan Kara return 0; 306966a6197cSJan Kara } 307066a6197cSJan Kara 3071dd906184SBoaz Harrosh /* 3072dd906184SBoaz Harrosh * Handle write page faults for VM_MIXEDMAP or VM_PFNMAP for a VM_SHARED 3073dd906184SBoaz Harrosh * mapping 3074dd906184SBoaz Harrosh */ 30752b740303SSouptick Joarder static vm_fault_t wp_pfn_shared(struct vm_fault *vmf) 3076dd906184SBoaz Harrosh { 307782b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 3078bae473a4SKirill A. Shutemov 3079dd906184SBoaz Harrosh if (vma->vm_ops && vma->vm_ops->pfn_mkwrite) { 30802b740303SSouptick Joarder vm_fault_t ret; 3081dd906184SBoaz Harrosh 308282b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 3083fe82221fSJan Kara vmf->flags |= FAULT_FLAG_MKWRITE; 308411bac800SDave Jiang ret = vma->vm_ops->pfn_mkwrite(vmf); 30852f89dc12SJan Kara if (ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)) 3086dd906184SBoaz Harrosh return ret; 308766a6197cSJan Kara return finish_mkwrite_fault(vmf); 3088dd906184SBoaz Harrosh } 3089997dd98dSJan Kara wp_page_reuse(vmf); 3090997dd98dSJan Kara return VM_FAULT_WRITE; 3091dd906184SBoaz Harrosh } 3092dd906184SBoaz Harrosh 30932b740303SSouptick Joarder static vm_fault_t wp_page_shared(struct vm_fault *vmf) 309482b0f8c3SJan Kara __releases(vmf->ptl) 309593e478d4SShachar Raindel { 309682b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 309789b15332SJohannes Weiner vm_fault_t ret = VM_FAULT_WRITE; 309893e478d4SShachar Raindel 3099a41b70d6SJan Kara get_page(vmf->page); 310093e478d4SShachar Raindel 310193e478d4SShachar Raindel if (vma->vm_ops && vma->vm_ops->page_mkwrite) { 31022b740303SSouptick Joarder vm_fault_t tmp; 310393e478d4SShachar Raindel 310482b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 310538b8cb7fSJan Kara tmp = do_page_mkwrite(vmf); 310693e478d4SShachar Raindel if (unlikely(!tmp || (tmp & 310793e478d4SShachar Raindel (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { 3108a41b70d6SJan Kara put_page(vmf->page); 310993e478d4SShachar Raindel return tmp; 311093e478d4SShachar Raindel } 311166a6197cSJan Kara tmp = finish_mkwrite_fault(vmf); 3112a19e2553SJan Kara if (unlikely(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) { 3113a41b70d6SJan Kara unlock_page(vmf->page); 3114a41b70d6SJan Kara put_page(vmf->page); 311566a6197cSJan Kara return tmp; 311693e478d4SShachar Raindel } 311766a6197cSJan Kara } else { 3118997dd98dSJan Kara wp_page_reuse(vmf); 3119997dd98dSJan Kara lock_page(vmf->page); 312093e478d4SShachar Raindel } 312189b15332SJohannes Weiner ret |= fault_dirty_shared_page(vmf); 3122997dd98dSJan Kara put_page(vmf->page); 312393e478d4SShachar Raindel 312489b15332SJohannes Weiner return ret; 312593e478d4SShachar Raindel } 312693e478d4SShachar Raindel 31272f38ab2cSShachar Raindel /* 31281da177e4SLinus Torvalds * This routine handles present pages, when users try to write 31291da177e4SLinus Torvalds * to a shared page. It is done by copying the page to a new address 31301da177e4SLinus Torvalds * and decrementing the shared-page counter for the old page. 31311da177e4SLinus Torvalds * 31321da177e4SLinus Torvalds * Note that this routine assumes that the protection checks have been 31331da177e4SLinus Torvalds * done by the caller (the low-level page fault routine in most cases). 31341da177e4SLinus Torvalds * Thus we can safely just mark it writable once we've done any necessary 31351da177e4SLinus Torvalds * COW. 31361da177e4SLinus Torvalds * 31371da177e4SLinus Torvalds * We also mark the page dirty at this point even though the page will 31381da177e4SLinus Torvalds * change only once the write actually happens. This avoids a few races, 31391da177e4SLinus Torvalds * and potentially makes it more efficient. 31401da177e4SLinus Torvalds * 3141c1e8d7c6SMichel Lespinasse * We enter with non-exclusive mmap_lock (to exclude vma changes, 31428f4e2101SHugh Dickins * but allow concurrent faults), with pte both mapped and locked. 3143c1e8d7c6SMichel Lespinasse * We return with mmap_lock still held, but pte unmapped and unlocked. 31441da177e4SLinus Torvalds */ 31452b740303SSouptick Joarder static vm_fault_t do_wp_page(struct vm_fault *vmf) 314682b0f8c3SJan Kara __releases(vmf->ptl) 31471da177e4SLinus Torvalds { 314882b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 31491da177e4SLinus Torvalds 3150292924b2SPeter Xu if (userfaultfd_pte_wp(vma, *vmf->pte)) { 3151529b930bSAndrea Arcangeli pte_unmap_unlock(vmf->pte, vmf->ptl); 3152529b930bSAndrea Arcangeli return handle_userfault(vmf, VM_UFFD_WP); 3153529b930bSAndrea Arcangeli } 3154529b930bSAndrea Arcangeli 31556ce64428SNadav Amit /* 31566ce64428SNadav Amit * Userfaultfd write-protect can defer flushes. Ensure the TLB 31576ce64428SNadav Amit * is flushed in this case before copying. 31586ce64428SNadav Amit */ 31596ce64428SNadav Amit if (unlikely(userfaultfd_wp(vmf->vma) && 31606ce64428SNadav Amit mm_tlb_flush_pending(vmf->vma->vm_mm))) 31616ce64428SNadav Amit flush_tlb_page(vmf->vma, vmf->address); 31626ce64428SNadav Amit 3163a41b70d6SJan Kara vmf->page = vm_normal_page(vma, vmf->address, vmf->orig_pte); 3164a41b70d6SJan Kara if (!vmf->page) { 3165251b97f5SPeter Zijlstra /* 316664e45507SPeter Feiner * VM_MIXEDMAP !pfn_valid() case, or VM_SOFTDIRTY clear on a 316764e45507SPeter Feiner * VM_PFNMAP VMA. 3168251b97f5SPeter Zijlstra * 3169251b97f5SPeter Zijlstra * We should not cow pages in a shared writeable mapping. 3170dd906184SBoaz Harrosh * Just mark the pages writable and/or call ops->pfn_mkwrite. 3171251b97f5SPeter Zijlstra */ 3172251b97f5SPeter Zijlstra if ((vma->vm_flags & (VM_WRITE|VM_SHARED)) == 3173251b97f5SPeter Zijlstra (VM_WRITE|VM_SHARED)) 31742994302bSJan Kara return wp_pfn_shared(vmf); 31752f38ab2cSShachar Raindel 317682b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 3177a41b70d6SJan Kara return wp_page_copy(vmf); 3178251b97f5SPeter Zijlstra } 31791da177e4SLinus Torvalds 3180d08b3851SPeter Zijlstra /* 3181ee6a6457SPeter Zijlstra * Take out anonymous pages first, anonymous shared vmas are 3182ee6a6457SPeter Zijlstra * not dirty accountable. 3183d08b3851SPeter Zijlstra */ 318452d1e606SKirill Tkhai if (PageAnon(vmf->page)) { 318509854ba9SLinus Torvalds struct page *page = vmf->page; 318609854ba9SLinus Torvalds 318709854ba9SLinus Torvalds /* PageKsm() doesn't necessarily raise the page refcount */ 318809854ba9SLinus Torvalds if (PageKsm(page) || page_count(page) != 1) 318952d1e606SKirill Tkhai goto copy; 319009854ba9SLinus Torvalds if (!trylock_page(page)) 319152d1e606SKirill Tkhai goto copy; 319209854ba9SLinus Torvalds if (PageKsm(page) || page_mapcount(page) != 1 || page_count(page) != 1) { 319309854ba9SLinus Torvalds unlock_page(page); 319409854ba9SLinus Torvalds goto copy; 319552d1e606SKirill Tkhai } 3196c44b6743SRik van Riel /* 319709854ba9SLinus Torvalds * Ok, we've got the only map reference, and the only 319809854ba9SLinus Torvalds * page count reference, and the page is locked, 319909854ba9SLinus Torvalds * it's dark out, and we're wearing sunglasses. Hit it. 3200c44b6743SRik van Riel */ 320109854ba9SLinus Torvalds unlock_page(page); 3202be068f29SLinus Torvalds wp_page_reuse(vmf); 3203997dd98dSJan Kara return VM_FAULT_WRITE; 3204ee6a6457SPeter Zijlstra } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == 3205d08b3851SPeter Zijlstra (VM_WRITE|VM_SHARED))) { 3206a41b70d6SJan Kara return wp_page_shared(vmf); 32071da177e4SLinus Torvalds } 320852d1e606SKirill Tkhai copy: 32091da177e4SLinus Torvalds /* 32101da177e4SLinus Torvalds * Ok, we need to copy. Oh, well.. 32111da177e4SLinus Torvalds */ 3212a41b70d6SJan Kara get_page(vmf->page); 321328766805SShachar Raindel 321482b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 3215a41b70d6SJan Kara return wp_page_copy(vmf); 32161da177e4SLinus Torvalds } 32171da177e4SLinus Torvalds 321897a89413SPeter Zijlstra static void unmap_mapping_range_vma(struct vm_area_struct *vma, 32191da177e4SLinus Torvalds unsigned long start_addr, unsigned long end_addr, 32201da177e4SLinus Torvalds struct zap_details *details) 32211da177e4SLinus Torvalds { 3222f5cc4eefSAl Viro zap_page_range_single(vma, start_addr, end_addr - start_addr, details); 32231da177e4SLinus Torvalds } 32241da177e4SLinus Torvalds 3225f808c13fSDavidlohr Bueso static inline void unmap_mapping_range_tree(struct rb_root_cached *root, 32261da177e4SLinus Torvalds struct zap_details *details) 32271da177e4SLinus Torvalds { 32281da177e4SLinus Torvalds struct vm_area_struct *vma; 32291da177e4SLinus Torvalds pgoff_t vba, vea, zba, zea; 32301da177e4SLinus Torvalds 32316b2dbba8SMichel Lespinasse vma_interval_tree_foreach(vma, root, 32321da177e4SLinus Torvalds details->first_index, details->last_index) { 32331da177e4SLinus Torvalds 32341da177e4SLinus Torvalds vba = vma->vm_pgoff; 3235d6e93217SLibin vea = vba + vma_pages(vma) - 1; 32361da177e4SLinus Torvalds zba = details->first_index; 32371da177e4SLinus Torvalds if (zba < vba) 32381da177e4SLinus Torvalds zba = vba; 32391da177e4SLinus Torvalds zea = details->last_index; 32401da177e4SLinus Torvalds if (zea > vea) 32411da177e4SLinus Torvalds zea = vea; 32421da177e4SLinus Torvalds 324397a89413SPeter Zijlstra unmap_mapping_range_vma(vma, 32441da177e4SLinus Torvalds ((zba - vba) << PAGE_SHIFT) + vma->vm_start, 32451da177e4SLinus Torvalds ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start, 324697a89413SPeter Zijlstra details); 32471da177e4SLinus Torvalds } 32481da177e4SLinus Torvalds } 32491da177e4SLinus Torvalds 32501da177e4SLinus Torvalds /** 325122061a1fSHugh Dickins * unmap_mapping_page() - Unmap single page from processes. 325222061a1fSHugh Dickins * @page: The locked page to be unmapped. 325322061a1fSHugh Dickins * 325422061a1fSHugh Dickins * Unmap this page from any userspace process which still has it mmaped. 325522061a1fSHugh Dickins * Typically, for efficiency, the range of nearby pages has already been 325622061a1fSHugh Dickins * unmapped by unmap_mapping_pages() or unmap_mapping_range(). But once 325722061a1fSHugh Dickins * truncation or invalidation holds the lock on a page, it may find that 325822061a1fSHugh Dickins * the page has been remapped again: and then uses unmap_mapping_page() 325922061a1fSHugh Dickins * to unmap it finally. 326022061a1fSHugh Dickins */ 326122061a1fSHugh Dickins void unmap_mapping_page(struct page *page) 326222061a1fSHugh Dickins { 326322061a1fSHugh Dickins struct address_space *mapping = page->mapping; 326422061a1fSHugh Dickins struct zap_details details = { }; 326522061a1fSHugh Dickins 326622061a1fSHugh Dickins VM_BUG_ON(!PageLocked(page)); 326722061a1fSHugh Dickins VM_BUG_ON(PageTail(page)); 326822061a1fSHugh Dickins 326922061a1fSHugh Dickins details.check_mapping = mapping; 327022061a1fSHugh Dickins details.first_index = page->index; 327122061a1fSHugh Dickins details.last_index = page->index + thp_nr_pages(page) - 1; 327222061a1fSHugh Dickins details.single_page = page; 327322061a1fSHugh Dickins 327422061a1fSHugh Dickins i_mmap_lock_write(mapping); 327522061a1fSHugh Dickins if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))) 327622061a1fSHugh Dickins unmap_mapping_range_tree(&mapping->i_mmap, &details); 327722061a1fSHugh Dickins i_mmap_unlock_write(mapping); 327822061a1fSHugh Dickins } 327922061a1fSHugh Dickins 328022061a1fSHugh Dickins /** 3281977fbdcdSMatthew Wilcox * unmap_mapping_pages() - Unmap pages from processes. 3282977fbdcdSMatthew Wilcox * @mapping: The address space containing pages to be unmapped. 3283977fbdcdSMatthew Wilcox * @start: Index of first page to be unmapped. 3284977fbdcdSMatthew Wilcox * @nr: Number of pages to be unmapped. 0 to unmap to end of file. 3285977fbdcdSMatthew Wilcox * @even_cows: Whether to unmap even private COWed pages. 3286977fbdcdSMatthew Wilcox * 3287977fbdcdSMatthew Wilcox * Unmap the pages in this address space from any userspace process which 3288977fbdcdSMatthew Wilcox * has them mmaped. Generally, you want to remove COWed pages as well when 3289977fbdcdSMatthew Wilcox * a file is being truncated, but not when invalidating pages from the page 3290977fbdcdSMatthew Wilcox * cache. 3291977fbdcdSMatthew Wilcox */ 3292977fbdcdSMatthew Wilcox void unmap_mapping_pages(struct address_space *mapping, pgoff_t start, 3293977fbdcdSMatthew Wilcox pgoff_t nr, bool even_cows) 3294977fbdcdSMatthew Wilcox { 3295977fbdcdSMatthew Wilcox struct zap_details details = { }; 3296977fbdcdSMatthew Wilcox 3297977fbdcdSMatthew Wilcox details.check_mapping = even_cows ? NULL : mapping; 3298977fbdcdSMatthew Wilcox details.first_index = start; 3299977fbdcdSMatthew Wilcox details.last_index = start + nr - 1; 3300977fbdcdSMatthew Wilcox if (details.last_index < details.first_index) 3301977fbdcdSMatthew Wilcox details.last_index = ULONG_MAX; 3302977fbdcdSMatthew Wilcox 3303977fbdcdSMatthew Wilcox i_mmap_lock_write(mapping); 3304977fbdcdSMatthew Wilcox if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))) 3305977fbdcdSMatthew Wilcox unmap_mapping_range_tree(&mapping->i_mmap, &details); 3306977fbdcdSMatthew Wilcox i_mmap_unlock_write(mapping); 3307977fbdcdSMatthew Wilcox } 3308977fbdcdSMatthew Wilcox 3309977fbdcdSMatthew Wilcox /** 33108a5f14a2SKirill A. Shutemov * unmap_mapping_range - unmap the portion of all mmaps in the specified 3311977fbdcdSMatthew Wilcox * address_space corresponding to the specified byte range in the underlying 33128a5f14a2SKirill A. Shutemov * file. 33138a5f14a2SKirill A. Shutemov * 33143d41088fSMartin Waitz * @mapping: the address space containing mmaps to be unmapped. 33151da177e4SLinus Torvalds * @holebegin: byte in first page to unmap, relative to the start of 33161da177e4SLinus Torvalds * the underlying file. This will be rounded down to a PAGE_SIZE 331725d9e2d1Snpiggin@suse.de * boundary. Note that this is different from truncate_pagecache(), which 33181da177e4SLinus Torvalds * must keep the partial page. In contrast, we must get rid of 33191da177e4SLinus Torvalds * partial pages. 33201da177e4SLinus Torvalds * @holelen: size of prospective hole in bytes. This will be rounded 33211da177e4SLinus Torvalds * up to a PAGE_SIZE boundary. A holelen of zero truncates to the 33221da177e4SLinus Torvalds * end of the file. 33231da177e4SLinus Torvalds * @even_cows: 1 when truncating a file, unmap even private COWed pages; 33241da177e4SLinus Torvalds * but 0 when invalidating pagecache, don't throw away private data. 33251da177e4SLinus Torvalds */ 33261da177e4SLinus Torvalds void unmap_mapping_range(struct address_space *mapping, 33271da177e4SLinus Torvalds loff_t const holebegin, loff_t const holelen, int even_cows) 33281da177e4SLinus Torvalds { 33291da177e4SLinus Torvalds pgoff_t hba = holebegin >> PAGE_SHIFT; 33301da177e4SLinus Torvalds pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; 33311da177e4SLinus Torvalds 33321da177e4SLinus Torvalds /* Check for overflow. */ 33331da177e4SLinus Torvalds if (sizeof(holelen) > sizeof(hlen)) { 33341da177e4SLinus Torvalds long long holeend = 33351da177e4SLinus Torvalds (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT; 33361da177e4SLinus Torvalds if (holeend & ~(long long)ULONG_MAX) 33371da177e4SLinus Torvalds hlen = ULONG_MAX - hba + 1; 33381da177e4SLinus Torvalds } 33391da177e4SLinus Torvalds 3340977fbdcdSMatthew Wilcox unmap_mapping_pages(mapping, hba, hlen, even_cows); 33411da177e4SLinus Torvalds } 33421da177e4SLinus Torvalds EXPORT_SYMBOL(unmap_mapping_range); 33431da177e4SLinus Torvalds 33441da177e4SLinus Torvalds /* 3345c1e8d7c6SMichel Lespinasse * We enter with non-exclusive mmap_lock (to exclude vma changes, 33468f4e2101SHugh Dickins * but allow concurrent faults), and pte mapped but not yet locked. 33479a95f3cfSPaul Cassella * We return with pte unmapped and unlocked. 33489a95f3cfSPaul Cassella * 3349c1e8d7c6SMichel Lespinasse * We return with the mmap_lock locked or unlocked in the same cases 33509a95f3cfSPaul Cassella * as does filemap_fault(). 33511da177e4SLinus Torvalds */ 33522b740303SSouptick Joarder vm_fault_t do_swap_page(struct vm_fault *vmf) 33531da177e4SLinus Torvalds { 335482b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 3355eaf649ebSMinchan Kim struct page *page = NULL, *swapcache; 3356*2799e775SMiaohe Lin struct swap_info_struct *si = NULL; 335765500d23SHugh Dickins swp_entry_t entry; 33581da177e4SLinus Torvalds pte_t pte; 3359d065bd81SMichel Lespinasse int locked; 3360ad8c2ee8SRik van Riel int exclusive = 0; 33612b740303SSouptick Joarder vm_fault_t ret = 0; 3362aae466b0SJoonsoo Kim void *shadow = NULL; 33631da177e4SLinus Torvalds 3364eaf649ebSMinchan Kim if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte)) 33658f4e2101SHugh Dickins goto out; 336665500d23SHugh Dickins 33672994302bSJan Kara entry = pte_to_swp_entry(vmf->orig_pte); 3368d1737fdbSAndi Kleen if (unlikely(non_swap_entry(entry))) { 33690697212aSChristoph Lameter if (is_migration_entry(entry)) { 337082b0f8c3SJan Kara migration_entry_wait(vma->vm_mm, vmf->pmd, 337182b0f8c3SJan Kara vmf->address); 33725042db43SJérôme Glisse } else if (is_device_private_entry(entry)) { 3373897e6365SChristoph Hellwig vmf->page = device_private_entry_to_page(entry); 3374897e6365SChristoph Hellwig ret = vmf->page->pgmap->ops->migrate_to_ram(vmf); 3375d1737fdbSAndi Kleen } else if (is_hwpoison_entry(entry)) { 3376d1737fdbSAndi Kleen ret = VM_FAULT_HWPOISON; 3377d1737fdbSAndi Kleen } else { 33782994302bSJan Kara print_bad_pte(vma, vmf->address, vmf->orig_pte, NULL); 3379d99be1a8SHugh Dickins ret = VM_FAULT_SIGBUS; 3380d1737fdbSAndi Kleen } 33810697212aSChristoph Lameter goto out; 33820697212aSChristoph Lameter } 33830bcac06fSMinchan Kim 3384*2799e775SMiaohe Lin /* Prevent swapoff from happening to us. */ 3385*2799e775SMiaohe Lin si = get_swap_device(entry); 3386*2799e775SMiaohe Lin if (unlikely(!si)) 3387*2799e775SMiaohe Lin goto out; 33880bcac06fSMinchan Kim 33893d1c7fd9SYafang Shao delayacct_set_flag(current, DELAYACCT_PF_SWAPIN); 3390eaf649ebSMinchan Kim page = lookup_swap_cache(entry, vma, vmf->address); 3391f8020772SMinchan Kim swapcache = page; 3392f8020772SMinchan Kim 33931da177e4SLinus Torvalds if (!page) { 3394a449bf58SQian Cai if (data_race(si->flags & SWP_SYNCHRONOUS_IO) && 3395eb085574SHuang Ying __swap_count(entry) == 1) { 33960bcac06fSMinchan Kim /* skip swapcache */ 3397e9e9b7ecSMinchan Kim page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, 3398e9e9b7ecSMinchan Kim vmf->address); 33990bcac06fSMinchan Kim if (page) { 34000bcac06fSMinchan Kim __SetPageLocked(page); 34010bcac06fSMinchan Kim __SetPageSwapBacked(page); 34024c6355b2SJohannes Weiner 34030add0c77SShakeel Butt if (mem_cgroup_swapin_charge_page(page, 34040add0c77SShakeel Butt vma->vm_mm, GFP_KERNEL, entry)) { 3405545b1b07SMichal Hocko ret = VM_FAULT_OOM; 34064c6355b2SJohannes Weiner goto out_page; 3407545b1b07SMichal Hocko } 34080add0c77SShakeel Butt mem_cgroup_swapin_uncharge_swap(entry); 34094c6355b2SJohannes Weiner 3410aae466b0SJoonsoo Kim shadow = get_shadow_from_swap_cache(entry); 3411aae466b0SJoonsoo Kim if (shadow) 3412aae466b0SJoonsoo Kim workingset_refault(page, shadow); 34130076f029SJoonsoo Kim 34146058eaecSJohannes Weiner lru_cache_add(page); 34150add0c77SShakeel Butt 34160add0c77SShakeel Butt /* To provide entry to swap_readpage() */ 34170add0c77SShakeel Butt set_page_private(page, entry.val); 34180bcac06fSMinchan Kim swap_readpage(page, true); 34190add0c77SShakeel Butt set_page_private(page, 0); 34200bcac06fSMinchan Kim } 3421aa8d22a1SMinchan Kim } else { 3422e9e9b7ecSMinchan Kim page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE, 3423e9e9b7ecSMinchan Kim vmf); 3424aa8d22a1SMinchan Kim swapcache = page; 34250bcac06fSMinchan Kim } 34260bcac06fSMinchan Kim 3427ec560175SHuang Ying if (!page) { 34281da177e4SLinus Torvalds /* 34298f4e2101SHugh Dickins * Back out if somebody else faulted in this pte 34308f4e2101SHugh Dickins * while we released the pte lock. 34311da177e4SLinus Torvalds */ 343282b0f8c3SJan Kara vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, 343382b0f8c3SJan Kara vmf->address, &vmf->ptl); 34342994302bSJan Kara if (likely(pte_same(*vmf->pte, vmf->orig_pte))) 34351da177e4SLinus Torvalds ret = VM_FAULT_OOM; 34363d1c7fd9SYafang Shao delayacct_clear_flag(current, DELAYACCT_PF_SWAPIN); 343765500d23SHugh Dickins goto unlock; 34381da177e4SLinus Torvalds } 34391da177e4SLinus Torvalds 34401da177e4SLinus Torvalds /* Had to read the page from swap area: Major fault */ 34411da177e4SLinus Torvalds ret = VM_FAULT_MAJOR; 3442f8891e5eSChristoph Lameter count_vm_event(PGMAJFAULT); 34432262185cSRoman Gushchin count_memcg_event_mm(vma->vm_mm, PGMAJFAULT); 3444d1737fdbSAndi Kleen } else if (PageHWPoison(page)) { 344571f72525SWu Fengguang /* 344671f72525SWu Fengguang * hwpoisoned dirty swapcache pages are kept for killing 344771f72525SWu Fengguang * owner processes (which may be unknown at hwpoison time) 344871f72525SWu Fengguang */ 3449d1737fdbSAndi Kleen ret = VM_FAULT_HWPOISON; 34503d1c7fd9SYafang Shao delayacct_clear_flag(current, DELAYACCT_PF_SWAPIN); 34514779cb31SAndi Kleen goto out_release; 34521da177e4SLinus Torvalds } 34531da177e4SLinus Torvalds 345482b0f8c3SJan Kara locked = lock_page_or_retry(page, vma->vm_mm, vmf->flags); 3455e709ffd6SRik van Riel 34563d1c7fd9SYafang Shao delayacct_clear_flag(current, DELAYACCT_PF_SWAPIN); 3457d065bd81SMichel Lespinasse if (!locked) { 3458d065bd81SMichel Lespinasse ret |= VM_FAULT_RETRY; 3459d065bd81SMichel Lespinasse goto out_release; 3460d065bd81SMichel Lespinasse } 34611da177e4SLinus Torvalds 34624969c119SAndrea Arcangeli /* 346331c4a3d3SHugh Dickins * Make sure try_to_free_swap or reuse_swap_page or swapoff did not 346431c4a3d3SHugh Dickins * release the swapcache from under us. The page pin, and pte_same 346531c4a3d3SHugh Dickins * test below, are not enough to exclude that. Even if it is still 346631c4a3d3SHugh Dickins * swapcache, we need to check that the page's swap has not changed. 34674969c119SAndrea Arcangeli */ 34680bcac06fSMinchan Kim if (unlikely((!PageSwapCache(page) || 34690bcac06fSMinchan Kim page_private(page) != entry.val)) && swapcache) 34704969c119SAndrea Arcangeli goto out_page; 34714969c119SAndrea Arcangeli 347282b0f8c3SJan Kara page = ksm_might_need_to_copy(page, vma, vmf->address); 34734969c119SAndrea Arcangeli if (unlikely(!page)) { 34745ad64688SHugh Dickins ret = VM_FAULT_OOM; 34754969c119SAndrea Arcangeli page = swapcache; 34764969c119SAndrea Arcangeli goto out_page; 34774969c119SAndrea Arcangeli } 34785ad64688SHugh Dickins 34799d82c694SJohannes Weiner cgroup_throttle_swaprate(page, GFP_KERNEL); 3480073e587eSKAMEZAWA Hiroyuki 34811da177e4SLinus Torvalds /* 34828f4e2101SHugh Dickins * Back out if somebody else already faulted in this pte. 34831da177e4SLinus Torvalds */ 348482b0f8c3SJan Kara vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, 348582b0f8c3SJan Kara &vmf->ptl); 34862994302bSJan Kara if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) 3487b8107480SKirill Korotaev goto out_nomap; 3488b8107480SKirill Korotaev 3489b8107480SKirill Korotaev if (unlikely(!PageUptodate(page))) { 3490b8107480SKirill Korotaev ret = VM_FAULT_SIGBUS; 3491b8107480SKirill Korotaev goto out_nomap; 34921da177e4SLinus Torvalds } 34931da177e4SLinus Torvalds 34948c7c6e34SKAMEZAWA Hiroyuki /* 34958c7c6e34SKAMEZAWA Hiroyuki * The page isn't present yet, go ahead with the fault. 34968c7c6e34SKAMEZAWA Hiroyuki * 34978c7c6e34SKAMEZAWA Hiroyuki * Be careful about the sequence of operations here. 34988c7c6e34SKAMEZAWA Hiroyuki * To get its accounting right, reuse_swap_page() must be called 34998c7c6e34SKAMEZAWA Hiroyuki * while the page is counted on swap but not yet in mapcount i.e. 35008c7c6e34SKAMEZAWA Hiroyuki * before page_add_anon_rmap() and swap_free(); try_to_free_swap() 35018c7c6e34SKAMEZAWA Hiroyuki * must be called after the swap_free(), or it will never succeed. 35028c7c6e34SKAMEZAWA Hiroyuki */ 35031da177e4SLinus Torvalds 3504bae473a4SKirill A. Shutemov inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); 3505bae473a4SKirill A. Shutemov dec_mm_counter_fast(vma->vm_mm, MM_SWAPENTS); 35061da177e4SLinus Torvalds pte = mk_pte(page, vma->vm_page_prot); 350782b0f8c3SJan Kara if ((vmf->flags & FAULT_FLAG_WRITE) && reuse_swap_page(page, NULL)) { 35081da177e4SLinus Torvalds pte = maybe_mkwrite(pte_mkdirty(pte), vma); 350982b0f8c3SJan Kara vmf->flags &= ~FAULT_FLAG_WRITE; 35109a5b489bSAndrea Arcangeli ret |= VM_FAULT_WRITE; 3511d281ee61SKirill A. Shutemov exclusive = RMAP_EXCLUSIVE; 35121da177e4SLinus Torvalds } 35131da177e4SLinus Torvalds flush_icache_page(vma, page); 35142994302bSJan Kara if (pte_swp_soft_dirty(vmf->orig_pte)) 3515179ef71cSCyrill Gorcunov pte = pte_mksoft_dirty(pte); 3516f45ec5ffSPeter Xu if (pte_swp_uffd_wp(vmf->orig_pte)) { 3517f45ec5ffSPeter Xu pte = pte_mkuffd_wp(pte); 3518f45ec5ffSPeter Xu pte = pte_wrprotect(pte); 3519f45ec5ffSPeter Xu } 352082b0f8c3SJan Kara set_pte_at(vma->vm_mm, vmf->address, vmf->pte, pte); 3521ca827d55SKhalid Aziz arch_do_swap_page(vma->vm_mm, vma, vmf->address, pte, vmf->orig_pte); 35222994302bSJan Kara vmf->orig_pte = pte; 35230bcac06fSMinchan Kim 35240bcac06fSMinchan Kim /* ksm created a completely new copy */ 35250bcac06fSMinchan Kim if (unlikely(page != swapcache && swapcache)) { 352682b0f8c3SJan Kara page_add_new_anon_rmap(page, vma, vmf->address, false); 3527b518154eSJoonsoo Kim lru_cache_add_inactive_or_unevictable(page, vma); 35280bcac06fSMinchan Kim } else { 35290bcac06fSMinchan Kim do_page_add_anon_rmap(page, vma, vmf->address, exclusive); 353000501b53SJohannes Weiner } 35311da177e4SLinus Torvalds 3532c475a8abSHugh Dickins swap_free(entry); 35335ccc5abaSVladimir Davydov if (mem_cgroup_swap_full(page) || 35345ccc5abaSVladimir Davydov (vma->vm_flags & VM_LOCKED) || PageMlocked(page)) 3535a2c43eedSHugh Dickins try_to_free_swap(page); 3536c475a8abSHugh Dickins unlock_page(page); 35370bcac06fSMinchan Kim if (page != swapcache && swapcache) { 35384969c119SAndrea Arcangeli /* 35394969c119SAndrea Arcangeli * Hold the lock to avoid the swap entry to be reused 35404969c119SAndrea Arcangeli * until we take the PT lock for the pte_same() check 35414969c119SAndrea Arcangeli * (to avoid false positives from pte_same). For 35424969c119SAndrea Arcangeli * further safety release the lock after the swap_free 35434969c119SAndrea Arcangeli * so that the swap count won't change under a 35444969c119SAndrea Arcangeli * parallel locked swapcache. 35454969c119SAndrea Arcangeli */ 35464969c119SAndrea Arcangeli unlock_page(swapcache); 354709cbfeafSKirill A. Shutemov put_page(swapcache); 35484969c119SAndrea Arcangeli } 3549c475a8abSHugh Dickins 355082b0f8c3SJan Kara if (vmf->flags & FAULT_FLAG_WRITE) { 35512994302bSJan Kara ret |= do_wp_page(vmf); 355261469f1dSHugh Dickins if (ret & VM_FAULT_ERROR) 355361469f1dSHugh Dickins ret &= VM_FAULT_ERROR; 35541da177e4SLinus Torvalds goto out; 35551da177e4SLinus Torvalds } 35561da177e4SLinus Torvalds 35571da177e4SLinus Torvalds /* No need to invalidate - it was non-present before */ 355882b0f8c3SJan Kara update_mmu_cache(vma, vmf->address, vmf->pte); 355965500d23SHugh Dickins unlock: 356082b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 35611da177e4SLinus Torvalds out: 3562*2799e775SMiaohe Lin if (si) 3563*2799e775SMiaohe Lin put_swap_device(si); 35641da177e4SLinus Torvalds return ret; 3565b8107480SKirill Korotaev out_nomap: 356682b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 3567bc43f75cSJohannes Weiner out_page: 3568b8107480SKirill Korotaev unlock_page(page); 35694779cb31SAndi Kleen out_release: 357009cbfeafSKirill A. Shutemov put_page(page); 35710bcac06fSMinchan Kim if (page != swapcache && swapcache) { 35724969c119SAndrea Arcangeli unlock_page(swapcache); 357309cbfeafSKirill A. Shutemov put_page(swapcache); 35744969c119SAndrea Arcangeli } 3575*2799e775SMiaohe Lin if (si) 3576*2799e775SMiaohe Lin put_swap_device(si); 357765500d23SHugh Dickins return ret; 35781da177e4SLinus Torvalds } 35791da177e4SLinus Torvalds 35801da177e4SLinus Torvalds /* 3581c1e8d7c6SMichel Lespinasse * We enter with non-exclusive mmap_lock (to exclude vma changes, 35828f4e2101SHugh Dickins * but allow concurrent faults), and pte mapped but not yet locked. 3583c1e8d7c6SMichel Lespinasse * We return with mmap_lock still held, but pte unmapped and unlocked. 35841da177e4SLinus Torvalds */ 35852b740303SSouptick Joarder static vm_fault_t do_anonymous_page(struct vm_fault *vmf) 35861da177e4SLinus Torvalds { 358782b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 35888f4e2101SHugh Dickins struct page *page; 35892b740303SSouptick Joarder vm_fault_t ret = 0; 35901da177e4SLinus Torvalds pte_t entry; 35911da177e4SLinus Torvalds 35926b7339f4SKirill A. Shutemov /* File mapping without ->vm_ops ? */ 35936b7339f4SKirill A. Shutemov if (vma->vm_flags & VM_SHARED) 35946b7339f4SKirill A. Shutemov return VM_FAULT_SIGBUS; 35956b7339f4SKirill A. Shutemov 35967267ec00SKirill A. Shutemov /* 35977267ec00SKirill A. Shutemov * Use pte_alloc() instead of pte_alloc_map(). We can't run 35987267ec00SKirill A. Shutemov * pte_offset_map() on pmds where a huge pmd might be created 35997267ec00SKirill A. Shutemov * from a different thread. 36007267ec00SKirill A. Shutemov * 36013e4e28c5SMichel Lespinasse * pte_alloc_map() is safe to use under mmap_write_lock(mm) or when 36027267ec00SKirill A. Shutemov * parallel threads are excluded by other means. 36037267ec00SKirill A. Shutemov * 36043e4e28c5SMichel Lespinasse * Here we only have mmap_read_lock(mm). 36057267ec00SKirill A. Shutemov */ 36064cf58924SJoel Fernandes (Google) if (pte_alloc(vma->vm_mm, vmf->pmd)) 36077267ec00SKirill A. Shutemov return VM_FAULT_OOM; 36087267ec00SKirill A. Shutemov 3609f9ce0be7SKirill A. Shutemov /* See comment in handle_pte_fault() */ 361082b0f8c3SJan Kara if (unlikely(pmd_trans_unstable(vmf->pmd))) 36117267ec00SKirill A. Shutemov return 0; 36127267ec00SKirill A. Shutemov 361311ac5524SLinus Torvalds /* Use the zero-page for reads */ 361482b0f8c3SJan Kara if (!(vmf->flags & FAULT_FLAG_WRITE) && 3615bae473a4SKirill A. Shutemov !mm_forbids_zeropage(vma->vm_mm)) { 361682b0f8c3SJan Kara entry = pte_mkspecial(pfn_pte(my_zero_pfn(vmf->address), 361762eede62SHugh Dickins vma->vm_page_prot)); 361882b0f8c3SJan Kara vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, 361982b0f8c3SJan Kara vmf->address, &vmf->ptl); 36207df67697SBibo Mao if (!pte_none(*vmf->pte)) { 36217df67697SBibo Mao update_mmu_tlb(vma, vmf->address, vmf->pte); 3622a13ea5b7SHugh Dickins goto unlock; 36237df67697SBibo Mao } 36246b31d595SMichal Hocko ret = check_stable_address_space(vma->vm_mm); 36256b31d595SMichal Hocko if (ret) 36266b31d595SMichal Hocko goto unlock; 36276b251fc9SAndrea Arcangeli /* Deliver the page fault to userland, check inside PT lock */ 36286b251fc9SAndrea Arcangeli if (userfaultfd_missing(vma)) { 362982b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 363082b0f8c3SJan Kara return handle_userfault(vmf, VM_UFFD_MISSING); 36316b251fc9SAndrea Arcangeli } 3632a13ea5b7SHugh Dickins goto setpte; 3633a13ea5b7SHugh Dickins } 3634a13ea5b7SHugh Dickins 36351da177e4SLinus Torvalds /* Allocate our own private page. */ 36361da177e4SLinus Torvalds if (unlikely(anon_vma_prepare(vma))) 363765500d23SHugh Dickins goto oom; 363882b0f8c3SJan Kara page = alloc_zeroed_user_highpage_movable(vma, vmf->address); 36391da177e4SLinus Torvalds if (!page) 364065500d23SHugh Dickins goto oom; 3641eb3c24f3SMel Gorman 3642d9eb1ea2SJohannes Weiner if (mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL)) 3643eb3c24f3SMel Gorman goto oom_free_page; 36449d82c694SJohannes Weiner cgroup_throttle_swaprate(page, GFP_KERNEL); 3645eb3c24f3SMel Gorman 364652f37629SMinchan Kim /* 364752f37629SMinchan Kim * The memory barrier inside __SetPageUptodate makes sure that 3648f4f5329dSWei Yang * preceding stores to the page contents become visible before 364952f37629SMinchan Kim * the set_pte_at() write. 365052f37629SMinchan Kim */ 36510ed361deSNick Piggin __SetPageUptodate(page); 36521da177e4SLinus Torvalds 365365500d23SHugh Dickins entry = mk_pte(page, vma->vm_page_prot); 365450c25ee9SThomas Bogendoerfer entry = pte_sw_mkyoung(entry); 36551ac0cb5dSHugh Dickins if (vma->vm_flags & VM_WRITE) 36561ac0cb5dSHugh Dickins entry = pte_mkwrite(pte_mkdirty(entry)); 36578f4e2101SHugh Dickins 365882b0f8c3SJan Kara vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, 365982b0f8c3SJan Kara &vmf->ptl); 36607df67697SBibo Mao if (!pte_none(*vmf->pte)) { 36617df67697SBibo Mao update_mmu_cache(vma, vmf->address, vmf->pte); 36628f4e2101SHugh Dickins goto release; 36637df67697SBibo Mao } 36649ba69294SHugh Dickins 36656b31d595SMichal Hocko ret = check_stable_address_space(vma->vm_mm); 36666b31d595SMichal Hocko if (ret) 36676b31d595SMichal Hocko goto release; 36686b31d595SMichal Hocko 36696b251fc9SAndrea Arcangeli /* Deliver the page fault to userland, check inside PT lock */ 36706b251fc9SAndrea Arcangeli if (userfaultfd_missing(vma)) { 367182b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 367209cbfeafSKirill A. Shutemov put_page(page); 367382b0f8c3SJan Kara return handle_userfault(vmf, VM_UFFD_MISSING); 36746b251fc9SAndrea Arcangeli } 36756b251fc9SAndrea Arcangeli 3676bae473a4SKirill A. Shutemov inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); 367782b0f8c3SJan Kara page_add_new_anon_rmap(page, vma, vmf->address, false); 3678b518154eSJoonsoo Kim lru_cache_add_inactive_or_unevictable(page, vma); 3679a13ea5b7SHugh Dickins setpte: 368082b0f8c3SJan Kara set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry); 36811da177e4SLinus Torvalds 36821da177e4SLinus Torvalds /* No need to invalidate - it was non-present before */ 368382b0f8c3SJan Kara update_mmu_cache(vma, vmf->address, vmf->pte); 368465500d23SHugh Dickins unlock: 368582b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 36866b31d595SMichal Hocko return ret; 36878f4e2101SHugh Dickins release: 368809cbfeafSKirill A. Shutemov put_page(page); 36898f4e2101SHugh Dickins goto unlock; 36908a9f3ccdSBalbir Singh oom_free_page: 369109cbfeafSKirill A. Shutemov put_page(page); 369265500d23SHugh Dickins oom: 36931da177e4SLinus Torvalds return VM_FAULT_OOM; 36941da177e4SLinus Torvalds } 36951da177e4SLinus Torvalds 36969a95f3cfSPaul Cassella /* 3697c1e8d7c6SMichel Lespinasse * The mmap_lock must have been held on entry, and may have been 36989a95f3cfSPaul Cassella * released depending on flags and vma->vm_ops->fault() return value. 36999a95f3cfSPaul Cassella * See filemap_fault() and __lock_page_retry(). 37009a95f3cfSPaul Cassella */ 37012b740303SSouptick Joarder static vm_fault_t __do_fault(struct vm_fault *vmf) 37027eae74afSKirill A. Shutemov { 370382b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 37042b740303SSouptick Joarder vm_fault_t ret; 37057eae74afSKirill A. Shutemov 370663f3655fSMichal Hocko /* 370763f3655fSMichal Hocko * Preallocate pte before we take page_lock because this might lead to 370863f3655fSMichal Hocko * deadlocks for memcg reclaim which waits for pages under writeback: 370963f3655fSMichal Hocko * lock_page(A) 371063f3655fSMichal Hocko * SetPageWriteback(A) 371163f3655fSMichal Hocko * unlock_page(A) 371263f3655fSMichal Hocko * lock_page(B) 371363f3655fSMichal Hocko * lock_page(B) 3714d383807aSYanfei Xu * pte_alloc_one 371563f3655fSMichal Hocko * shrink_page_list 371663f3655fSMichal Hocko * wait_on_page_writeback(A) 371763f3655fSMichal Hocko * SetPageWriteback(B) 371863f3655fSMichal Hocko * unlock_page(B) 371963f3655fSMichal Hocko * # flush A, B to clear the writeback 372063f3655fSMichal Hocko */ 372163f3655fSMichal Hocko if (pmd_none(*vmf->pmd) && !vmf->prealloc_pte) { 3722a7069ee3SYanfei Xu vmf->prealloc_pte = pte_alloc_one(vma->vm_mm); 372363f3655fSMichal Hocko if (!vmf->prealloc_pte) 372463f3655fSMichal Hocko return VM_FAULT_OOM; 372563f3655fSMichal Hocko smp_wmb(); /* See comment in __pte_alloc() */ 372663f3655fSMichal Hocko } 372763f3655fSMichal Hocko 372811bac800SDave Jiang ret = vma->vm_ops->fault(vmf); 37293917048dSJan Kara if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY | 3730b1aa812bSJan Kara VM_FAULT_DONE_COW))) 37317eae74afSKirill A. Shutemov return ret; 37327eae74afSKirill A. Shutemov 3733667240e0SJan Kara if (unlikely(PageHWPoison(vmf->page))) { 37347eae74afSKirill A. Shutemov if (ret & VM_FAULT_LOCKED) 3735667240e0SJan Kara unlock_page(vmf->page); 3736667240e0SJan Kara put_page(vmf->page); 3737936ca80dSJan Kara vmf->page = NULL; 37387eae74afSKirill A. Shutemov return VM_FAULT_HWPOISON; 37397eae74afSKirill A. Shutemov } 37407eae74afSKirill A. Shutemov 37417eae74afSKirill A. Shutemov if (unlikely(!(ret & VM_FAULT_LOCKED))) 3742667240e0SJan Kara lock_page(vmf->page); 37437eae74afSKirill A. Shutemov else 3744667240e0SJan Kara VM_BUG_ON_PAGE(!PageLocked(vmf->page), vmf->page); 37457eae74afSKirill A. Shutemov 37467eae74afSKirill A. Shutemov return ret; 37477eae74afSKirill A. Shutemov } 37487eae74afSKirill A. Shutemov 3749396bcc52SMatthew Wilcox (Oracle) #ifdef CONFIG_TRANSPARENT_HUGEPAGE 375082b0f8c3SJan Kara static void deposit_prealloc_pte(struct vm_fault *vmf) 3751953c66c2SAneesh Kumar K.V { 375282b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 3753953c66c2SAneesh Kumar K.V 375482b0f8c3SJan Kara pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, vmf->prealloc_pte); 3755953c66c2SAneesh Kumar K.V /* 3756953c66c2SAneesh Kumar K.V * We are going to consume the prealloc table, 3757953c66c2SAneesh Kumar K.V * count that as nr_ptes. 3758953c66c2SAneesh Kumar K.V */ 3759c4812909SKirill A. Shutemov mm_inc_nr_ptes(vma->vm_mm); 37607f2b6ce8STobin C Harding vmf->prealloc_pte = NULL; 3761953c66c2SAneesh Kumar K.V } 3762953c66c2SAneesh Kumar K.V 3763f9ce0be7SKirill A. Shutemov vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page) 376410102459SKirill A. Shutemov { 376582b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 376682b0f8c3SJan Kara bool write = vmf->flags & FAULT_FLAG_WRITE; 376782b0f8c3SJan Kara unsigned long haddr = vmf->address & HPAGE_PMD_MASK; 376810102459SKirill A. Shutemov pmd_t entry; 37692b740303SSouptick Joarder int i; 3770d01ac3c3SMatthew Wilcox (Oracle) vm_fault_t ret = VM_FAULT_FALLBACK; 377110102459SKirill A. Shutemov 377210102459SKirill A. Shutemov if (!transhuge_vma_suitable(vma, haddr)) 3773d01ac3c3SMatthew Wilcox (Oracle) return ret; 377410102459SKirill A. Shutemov 377510102459SKirill A. Shutemov page = compound_head(page); 3776d01ac3c3SMatthew Wilcox (Oracle) if (compound_order(page) != HPAGE_PMD_ORDER) 3777d01ac3c3SMatthew Wilcox (Oracle) return ret; 377810102459SKirill A. Shutemov 3779953c66c2SAneesh Kumar K.V /* 3780f0953a1bSIngo Molnar * Archs like ppc64 need additional space to store information 3781953c66c2SAneesh Kumar K.V * related to pte entry. Use the preallocated table for that. 3782953c66c2SAneesh Kumar K.V */ 378382b0f8c3SJan Kara if (arch_needs_pgtable_deposit() && !vmf->prealloc_pte) { 37844cf58924SJoel Fernandes (Google) vmf->prealloc_pte = pte_alloc_one(vma->vm_mm); 378582b0f8c3SJan Kara if (!vmf->prealloc_pte) 3786953c66c2SAneesh Kumar K.V return VM_FAULT_OOM; 3787953c66c2SAneesh Kumar K.V smp_wmb(); /* See comment in __pte_alloc() */ 3788953c66c2SAneesh Kumar K.V } 3789953c66c2SAneesh Kumar K.V 379082b0f8c3SJan Kara vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); 379182b0f8c3SJan Kara if (unlikely(!pmd_none(*vmf->pmd))) 379210102459SKirill A. Shutemov goto out; 379310102459SKirill A. Shutemov 379410102459SKirill A. Shutemov for (i = 0; i < HPAGE_PMD_NR; i++) 379510102459SKirill A. Shutemov flush_icache_page(vma, page + i); 379610102459SKirill A. Shutemov 379710102459SKirill A. Shutemov entry = mk_huge_pmd(page, vma->vm_page_prot); 379810102459SKirill A. Shutemov if (write) 3799f55e1014SLinus Torvalds entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); 380010102459SKirill A. Shutemov 3801fadae295SYang Shi add_mm_counter(vma->vm_mm, mm_counter_file(page), HPAGE_PMD_NR); 380210102459SKirill A. Shutemov page_add_file_rmap(page, true); 3803953c66c2SAneesh Kumar K.V /* 3804953c66c2SAneesh Kumar K.V * deposit and withdraw with pmd lock held 3805953c66c2SAneesh Kumar K.V */ 3806953c66c2SAneesh Kumar K.V if (arch_needs_pgtable_deposit()) 380782b0f8c3SJan Kara deposit_prealloc_pte(vmf); 380810102459SKirill A. Shutemov 380982b0f8c3SJan Kara set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); 381010102459SKirill A. Shutemov 381182b0f8c3SJan Kara update_mmu_cache_pmd(vma, haddr, vmf->pmd); 381210102459SKirill A. Shutemov 381310102459SKirill A. Shutemov /* fault is handled */ 381410102459SKirill A. Shutemov ret = 0; 381595ecedcdSKirill A. Shutemov count_vm_event(THP_FILE_MAPPED); 381610102459SKirill A. Shutemov out: 381782b0f8c3SJan Kara spin_unlock(vmf->ptl); 381810102459SKirill A. Shutemov return ret; 381910102459SKirill A. Shutemov } 382010102459SKirill A. Shutemov #else 3821f9ce0be7SKirill A. Shutemov vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page) 382210102459SKirill A. Shutemov { 3823f9ce0be7SKirill A. Shutemov return VM_FAULT_FALLBACK; 382410102459SKirill A. Shutemov } 382510102459SKirill A. Shutemov #endif 382610102459SKirill A. Shutemov 38279d3af4b4SWill Deacon void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr) 38283bb97794SKirill A. Shutemov { 382982b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 383082b0f8c3SJan Kara bool write = vmf->flags & FAULT_FLAG_WRITE; 38319d3af4b4SWill Deacon bool prefault = vmf->address != addr; 38323bb97794SKirill A. Shutemov pte_t entry; 38337267ec00SKirill A. Shutemov 38343bb97794SKirill A. Shutemov flush_icache_page(vma, page); 38353bb97794SKirill A. Shutemov entry = mk_pte(page, vma->vm_page_prot); 383646bdb427SWill Deacon 383746bdb427SWill Deacon if (prefault && arch_wants_old_prefaulted_pte()) 383846bdb427SWill Deacon entry = pte_mkold(entry); 383950c25ee9SThomas Bogendoerfer else 384050c25ee9SThomas Bogendoerfer entry = pte_sw_mkyoung(entry); 384146bdb427SWill Deacon 38423bb97794SKirill A. Shutemov if (write) 38433bb97794SKirill A. Shutemov entry = maybe_mkwrite(pte_mkdirty(entry), vma); 3844bae473a4SKirill A. Shutemov /* copy-on-write page */ 3845bae473a4SKirill A. Shutemov if (write && !(vma->vm_flags & VM_SHARED)) { 38463bb97794SKirill A. Shutemov inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); 38479d3af4b4SWill Deacon page_add_new_anon_rmap(page, vma, addr, false); 3848b518154eSJoonsoo Kim lru_cache_add_inactive_or_unevictable(page, vma); 38493bb97794SKirill A. Shutemov } else { 3850eca56ff9SJerome Marchand inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page)); 3851dd78feddSKirill A. Shutemov page_add_file_rmap(page, false); 38523bb97794SKirill A. Shutemov } 38539d3af4b4SWill Deacon set_pte_at(vma->vm_mm, addr, vmf->pte, entry); 38543bb97794SKirill A. Shutemov } 38553bb97794SKirill A. Shutemov 38569118c0cbSJan Kara /** 38579118c0cbSJan Kara * finish_fault - finish page fault once we have prepared the page to fault 38589118c0cbSJan Kara * 38599118c0cbSJan Kara * @vmf: structure describing the fault 38609118c0cbSJan Kara * 38619118c0cbSJan Kara * This function handles all that is needed to finish a page fault once the 38629118c0cbSJan Kara * page to fault in is prepared. It handles locking of PTEs, inserts PTE for 38639118c0cbSJan Kara * given page, adds reverse page mapping, handles memcg charges and LRU 3864a862f68aSMike Rapoport * addition. 38659118c0cbSJan Kara * 38669118c0cbSJan Kara * The function expects the page to be locked and on success it consumes a 38679118c0cbSJan Kara * reference of a page being mapped (for the PTE which maps it). 3868a862f68aSMike Rapoport * 3869a862f68aSMike Rapoport * Return: %0 on success, %VM_FAULT_ code in case of error. 38709118c0cbSJan Kara */ 38712b740303SSouptick Joarder vm_fault_t finish_fault(struct vm_fault *vmf) 38729118c0cbSJan Kara { 3873f9ce0be7SKirill A. Shutemov struct vm_area_struct *vma = vmf->vma; 38749118c0cbSJan Kara struct page *page; 3875f9ce0be7SKirill A. Shutemov vm_fault_t ret; 38769118c0cbSJan Kara 38779118c0cbSJan Kara /* Did we COW the page? */ 3878f9ce0be7SKirill A. Shutemov if ((vmf->flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) 38799118c0cbSJan Kara page = vmf->cow_page; 38809118c0cbSJan Kara else 38819118c0cbSJan Kara page = vmf->page; 38826b31d595SMichal Hocko 38836b31d595SMichal Hocko /* 38846b31d595SMichal Hocko * check even for read faults because we might have lost our CoWed 38856b31d595SMichal Hocko * page 38866b31d595SMichal Hocko */ 3887f9ce0be7SKirill A. Shutemov if (!(vma->vm_flags & VM_SHARED)) { 3888f9ce0be7SKirill A. Shutemov ret = check_stable_address_space(vma->vm_mm); 3889f9ce0be7SKirill A. Shutemov if (ret) 3890f9ce0be7SKirill A. Shutemov return ret; 3891f9ce0be7SKirill A. Shutemov } 3892f9ce0be7SKirill A. Shutemov 3893f9ce0be7SKirill A. Shutemov if (pmd_none(*vmf->pmd)) { 3894f9ce0be7SKirill A. Shutemov if (PageTransCompound(page)) { 3895f9ce0be7SKirill A. Shutemov ret = do_set_pmd(vmf, page); 3896f9ce0be7SKirill A. Shutemov if (ret != VM_FAULT_FALLBACK) 3897f9ce0be7SKirill A. Shutemov return ret; 3898f9ce0be7SKirill A. Shutemov } 3899f9ce0be7SKirill A. Shutemov 3900f9ce0be7SKirill A. Shutemov if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd))) 3901f9ce0be7SKirill A. Shutemov return VM_FAULT_OOM; 3902f9ce0be7SKirill A. Shutemov } 3903f9ce0be7SKirill A. Shutemov 3904f9ce0be7SKirill A. Shutemov /* See comment in handle_pte_fault() */ 3905f9ce0be7SKirill A. Shutemov if (pmd_devmap_trans_unstable(vmf->pmd)) 3906f9ce0be7SKirill A. Shutemov return 0; 3907f9ce0be7SKirill A. Shutemov 3908f9ce0be7SKirill A. Shutemov vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, 3909f9ce0be7SKirill A. Shutemov vmf->address, &vmf->ptl); 3910f9ce0be7SKirill A. Shutemov ret = 0; 3911f9ce0be7SKirill A. Shutemov /* Re-check under ptl */ 3912f9ce0be7SKirill A. Shutemov if (likely(pte_none(*vmf->pte))) 39139d3af4b4SWill Deacon do_set_pte(vmf, page, vmf->address); 3914f9ce0be7SKirill A. Shutemov else 3915f9ce0be7SKirill A. Shutemov ret = VM_FAULT_NOPAGE; 3916f9ce0be7SKirill A. Shutemov 3917f9ce0be7SKirill A. Shutemov update_mmu_tlb(vma, vmf->address, vmf->pte); 39189118c0cbSJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 39199118c0cbSJan Kara return ret; 39209118c0cbSJan Kara } 39219118c0cbSJan Kara 39223a91053aSKirill A. Shutemov static unsigned long fault_around_bytes __read_mostly = 39233a91053aSKirill A. Shutemov rounddown_pow_of_two(65536); 3924a9b0f861SKirill A. Shutemov 39251592eef0SKirill A. Shutemov #ifdef CONFIG_DEBUG_FS 3926a9b0f861SKirill A. Shutemov static int fault_around_bytes_get(void *data, u64 *val) 39271592eef0SKirill A. Shutemov { 3928a9b0f861SKirill A. Shutemov *val = fault_around_bytes; 39291592eef0SKirill A. Shutemov return 0; 39301592eef0SKirill A. Shutemov } 39311592eef0SKirill A. Shutemov 3932b4903d6eSAndrey Ryabinin /* 3933da391d64SWilliam Kucharski * fault_around_bytes must be rounded down to the nearest page order as it's 3934da391d64SWilliam Kucharski * what do_fault_around() expects to see. 3935b4903d6eSAndrey Ryabinin */ 3936a9b0f861SKirill A. Shutemov static int fault_around_bytes_set(void *data, u64 val) 39371592eef0SKirill A. Shutemov { 3938a9b0f861SKirill A. Shutemov if (val / PAGE_SIZE > PTRS_PER_PTE) 39391592eef0SKirill A. Shutemov return -EINVAL; 3940b4903d6eSAndrey Ryabinin if (val > PAGE_SIZE) 3941b4903d6eSAndrey Ryabinin fault_around_bytes = rounddown_pow_of_two(val); 3942b4903d6eSAndrey Ryabinin else 3943b4903d6eSAndrey Ryabinin fault_around_bytes = PAGE_SIZE; /* rounddown_pow_of_two(0) is undefined */ 39441592eef0SKirill A. Shutemov return 0; 39451592eef0SKirill A. Shutemov } 39460a1345f8SYevgen Pronenko DEFINE_DEBUGFS_ATTRIBUTE(fault_around_bytes_fops, 3947a9b0f861SKirill A. Shutemov fault_around_bytes_get, fault_around_bytes_set, "%llu\n"); 39481592eef0SKirill A. Shutemov 39491592eef0SKirill A. Shutemov static int __init fault_around_debugfs(void) 39501592eef0SKirill A. Shutemov { 3951d9f7979cSGreg Kroah-Hartman debugfs_create_file_unsafe("fault_around_bytes", 0644, NULL, NULL, 3952a9b0f861SKirill A. Shutemov &fault_around_bytes_fops); 39531592eef0SKirill A. Shutemov return 0; 39541592eef0SKirill A. Shutemov } 39551592eef0SKirill A. Shutemov late_initcall(fault_around_debugfs); 39561592eef0SKirill A. Shutemov #endif 39578c6e50b0SKirill A. Shutemov 39581fdb412bSKirill A. Shutemov /* 39591fdb412bSKirill A. Shutemov * do_fault_around() tries to map few pages around the fault address. The hope 39601fdb412bSKirill A. Shutemov * is that the pages will be needed soon and this will lower the number of 39611fdb412bSKirill A. Shutemov * faults to handle. 39621fdb412bSKirill A. Shutemov * 39631fdb412bSKirill A. Shutemov * It uses vm_ops->map_pages() to map the pages, which skips the page if it's 39641fdb412bSKirill A. Shutemov * not ready to be mapped: not up-to-date, locked, etc. 39651fdb412bSKirill A. Shutemov * 39661fdb412bSKirill A. Shutemov * This function is called with the page table lock taken. In the split ptlock 39671fdb412bSKirill A. Shutemov * case the page table lock only protects only those entries which belong to 39681fdb412bSKirill A. Shutemov * the page table corresponding to the fault address. 39691fdb412bSKirill A. Shutemov * 39701fdb412bSKirill A. Shutemov * This function doesn't cross the VMA boundaries, in order to call map_pages() 39711fdb412bSKirill A. Shutemov * only once. 39721fdb412bSKirill A. Shutemov * 3973da391d64SWilliam Kucharski * fault_around_bytes defines how many bytes we'll try to map. 3974da391d64SWilliam Kucharski * do_fault_around() expects it to be set to a power of two less than or equal 3975da391d64SWilliam Kucharski * to PTRS_PER_PTE. 39761fdb412bSKirill A. Shutemov * 3977da391d64SWilliam Kucharski * The virtual address of the area that we map is naturally aligned to 3978da391d64SWilliam Kucharski * fault_around_bytes rounded down to the machine page size 3979da391d64SWilliam Kucharski * (and therefore to page order). This way it's easier to guarantee 3980da391d64SWilliam Kucharski * that we don't cross page table boundaries. 39811fdb412bSKirill A. Shutemov */ 39822b740303SSouptick Joarder static vm_fault_t do_fault_around(struct vm_fault *vmf) 39838c6e50b0SKirill A. Shutemov { 398482b0f8c3SJan Kara unsigned long address = vmf->address, nr_pages, mask; 39850721ec8bSJan Kara pgoff_t start_pgoff = vmf->pgoff; 3986bae473a4SKirill A. Shutemov pgoff_t end_pgoff; 39872b740303SSouptick Joarder int off; 39888c6e50b0SKirill A. Shutemov 39894db0c3c2SJason Low nr_pages = READ_ONCE(fault_around_bytes) >> PAGE_SHIFT; 3990aecd6f44SKirill A. Shutemov mask = ~(nr_pages * PAGE_SIZE - 1) & PAGE_MASK; 3991aecd6f44SKirill A. Shutemov 3992f9ce0be7SKirill A. Shutemov address = max(address & mask, vmf->vma->vm_start); 3993f9ce0be7SKirill A. Shutemov off = ((vmf->address - address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1); 3994bae473a4SKirill A. Shutemov start_pgoff -= off; 39958c6e50b0SKirill A. Shutemov 39968c6e50b0SKirill A. Shutemov /* 3997da391d64SWilliam Kucharski * end_pgoff is either the end of the page table, the end of 3998da391d64SWilliam Kucharski * the vma or nr_pages from start_pgoff, depending what is nearest. 39998c6e50b0SKirill A. Shutemov */ 4000bae473a4SKirill A. Shutemov end_pgoff = start_pgoff - 4001f9ce0be7SKirill A. Shutemov ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) + 40028c6e50b0SKirill A. Shutemov PTRS_PER_PTE - 1; 400382b0f8c3SJan Kara end_pgoff = min3(end_pgoff, vma_pages(vmf->vma) + vmf->vma->vm_pgoff - 1, 4004bae473a4SKirill A. Shutemov start_pgoff + nr_pages - 1); 40058c6e50b0SKirill A. Shutemov 400682b0f8c3SJan Kara if (pmd_none(*vmf->pmd)) { 40074cf58924SJoel Fernandes (Google) vmf->prealloc_pte = pte_alloc_one(vmf->vma->vm_mm); 400882b0f8c3SJan Kara if (!vmf->prealloc_pte) 4009f9ce0be7SKirill A. Shutemov return VM_FAULT_OOM; 40107267ec00SKirill A. Shutemov smp_wmb(); /* See comment in __pte_alloc() */ 40118c6e50b0SKirill A. Shutemov } 40128c6e50b0SKirill A. Shutemov 4013f9ce0be7SKirill A. Shutemov return vmf->vma->vm_ops->map_pages(vmf, start_pgoff, end_pgoff); 40147267ec00SKirill A. Shutemov } 40157267ec00SKirill A. Shutemov 40162b740303SSouptick Joarder static vm_fault_t do_read_fault(struct vm_fault *vmf) 4017e655fb29SKirill A. Shutemov { 401882b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 40192b740303SSouptick Joarder vm_fault_t ret = 0; 40208c6e50b0SKirill A. Shutemov 40218c6e50b0SKirill A. Shutemov /* 40228c6e50b0SKirill A. Shutemov * Let's call ->map_pages() first and use ->fault() as fallback 40238c6e50b0SKirill A. Shutemov * if page by the offset is not ready to be mapped (cold cache or 40248c6e50b0SKirill A. Shutemov * something). 40258c6e50b0SKirill A. Shutemov */ 40269b4bdd2fSKirill A. Shutemov if (vma->vm_ops->map_pages && fault_around_bytes >> PAGE_SHIFT > 1) { 40270721ec8bSJan Kara ret = do_fault_around(vmf); 40287267ec00SKirill A. Shutemov if (ret) 40297267ec00SKirill A. Shutemov return ret; 40308c6e50b0SKirill A. Shutemov } 4031e655fb29SKirill A. Shutemov 4032936ca80dSJan Kara ret = __do_fault(vmf); 4033e655fb29SKirill A. Shutemov if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) 4034e655fb29SKirill A. Shutemov return ret; 4035e655fb29SKirill A. Shutemov 40369118c0cbSJan Kara ret |= finish_fault(vmf); 4037936ca80dSJan Kara unlock_page(vmf->page); 40387267ec00SKirill A. Shutemov if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) 4039936ca80dSJan Kara put_page(vmf->page); 4040e655fb29SKirill A. Shutemov return ret; 4041e655fb29SKirill A. Shutemov } 4042e655fb29SKirill A. Shutemov 40432b740303SSouptick Joarder static vm_fault_t do_cow_fault(struct vm_fault *vmf) 4044ec47c3b9SKirill A. Shutemov { 404582b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 40462b740303SSouptick Joarder vm_fault_t ret; 4047ec47c3b9SKirill A. Shutemov 4048ec47c3b9SKirill A. Shutemov if (unlikely(anon_vma_prepare(vma))) 4049ec47c3b9SKirill A. Shutemov return VM_FAULT_OOM; 4050ec47c3b9SKirill A. Shutemov 4051936ca80dSJan Kara vmf->cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address); 4052936ca80dSJan Kara if (!vmf->cow_page) 4053ec47c3b9SKirill A. Shutemov return VM_FAULT_OOM; 4054ec47c3b9SKirill A. Shutemov 4055d9eb1ea2SJohannes Weiner if (mem_cgroup_charge(vmf->cow_page, vma->vm_mm, GFP_KERNEL)) { 4056936ca80dSJan Kara put_page(vmf->cow_page); 4057ec47c3b9SKirill A. Shutemov return VM_FAULT_OOM; 4058ec47c3b9SKirill A. Shutemov } 40599d82c694SJohannes Weiner cgroup_throttle_swaprate(vmf->cow_page, GFP_KERNEL); 4060ec47c3b9SKirill A. Shutemov 4061936ca80dSJan Kara ret = __do_fault(vmf); 4062ec47c3b9SKirill A. Shutemov if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) 4063ec47c3b9SKirill A. Shutemov goto uncharge_out; 40643917048dSJan Kara if (ret & VM_FAULT_DONE_COW) 40653917048dSJan Kara return ret; 4066ec47c3b9SKirill A. Shutemov 4067936ca80dSJan Kara copy_user_highpage(vmf->cow_page, vmf->page, vmf->address, vma); 4068936ca80dSJan Kara __SetPageUptodate(vmf->cow_page); 4069ec47c3b9SKirill A. Shutemov 40709118c0cbSJan Kara ret |= finish_fault(vmf); 4071936ca80dSJan Kara unlock_page(vmf->page); 4072936ca80dSJan Kara put_page(vmf->page); 40737267ec00SKirill A. Shutemov if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) 40747267ec00SKirill A. Shutemov goto uncharge_out; 4075ec47c3b9SKirill A. Shutemov return ret; 4076ec47c3b9SKirill A. Shutemov uncharge_out: 4077936ca80dSJan Kara put_page(vmf->cow_page); 4078ec47c3b9SKirill A. Shutemov return ret; 4079ec47c3b9SKirill A. Shutemov } 4080ec47c3b9SKirill A. Shutemov 40812b740303SSouptick Joarder static vm_fault_t do_shared_fault(struct vm_fault *vmf) 40821da177e4SLinus Torvalds { 408382b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 40842b740303SSouptick Joarder vm_fault_t ret, tmp; 40851d65f86dSKAMEZAWA Hiroyuki 4086936ca80dSJan Kara ret = __do_fault(vmf); 40877eae74afSKirill A. Shutemov if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY))) 4088f0c6d4d2SKirill A. Shutemov return ret; 40891da177e4SLinus Torvalds 40901da177e4SLinus Torvalds /* 4091f0c6d4d2SKirill A. Shutemov * Check if the backing address space wants to know that the page is 4092f0c6d4d2SKirill A. Shutemov * about to become writable 40931da177e4SLinus Torvalds */ 4094fb09a464SKirill A. Shutemov if (vma->vm_ops->page_mkwrite) { 4095936ca80dSJan Kara unlock_page(vmf->page); 409638b8cb7fSJan Kara tmp = do_page_mkwrite(vmf); 4097fb09a464SKirill A. Shutemov if (unlikely(!tmp || 4098fb09a464SKirill A. Shutemov (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) { 4099936ca80dSJan Kara put_page(vmf->page); 4100f0c6d4d2SKirill A. Shutemov return tmp; 410169676147SMark Fasheh } 4102d0217ac0SNick Piggin } 4103fb09a464SKirill A. Shutemov 41049118c0cbSJan Kara ret |= finish_fault(vmf); 41057267ec00SKirill A. Shutemov if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | 41067267ec00SKirill A. Shutemov VM_FAULT_RETRY))) { 4107936ca80dSJan Kara unlock_page(vmf->page); 4108936ca80dSJan Kara put_page(vmf->page); 4109f0c6d4d2SKirill A. Shutemov return ret; 41109637a5efSDavid Howells } 4111d00806b1SNick Piggin 411289b15332SJohannes Weiner ret |= fault_dirty_shared_page(vmf); 4113b827e496SNick Piggin return ret; 411454cb8821SNick Piggin } 4115d00806b1SNick Piggin 41169a95f3cfSPaul Cassella /* 4117c1e8d7c6SMichel Lespinasse * We enter with non-exclusive mmap_lock (to exclude vma changes, 41189a95f3cfSPaul Cassella * but allow concurrent faults). 4119c1e8d7c6SMichel Lespinasse * The mmap_lock may have been released depending on flags and our 41209a95f3cfSPaul Cassella * return value. See filemap_fault() and __lock_page_or_retry(). 4121c1e8d7c6SMichel Lespinasse * If mmap_lock is released, vma may become invalid (for example 4122fc8efd2dSJan Stancek * by other thread calling munmap()). 41239a95f3cfSPaul Cassella */ 41242b740303SSouptick Joarder static vm_fault_t do_fault(struct vm_fault *vmf) 412554cb8821SNick Piggin { 412682b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 4127fc8efd2dSJan Stancek struct mm_struct *vm_mm = vma->vm_mm; 41282b740303SSouptick Joarder vm_fault_t ret; 412954cb8821SNick Piggin 4130ff09d7ecSAneesh Kumar K.V /* 4131ff09d7ecSAneesh Kumar K.V * The VMA was not fully populated on mmap() or missing VM_DONTEXPAND 4132ff09d7ecSAneesh Kumar K.V */ 4133ff09d7ecSAneesh Kumar K.V if (!vma->vm_ops->fault) { 4134ff09d7ecSAneesh Kumar K.V /* 4135ff09d7ecSAneesh Kumar K.V * If we find a migration pmd entry or a none pmd entry, which 4136ff09d7ecSAneesh Kumar K.V * should never happen, return SIGBUS 4137ff09d7ecSAneesh Kumar K.V */ 4138ff09d7ecSAneesh Kumar K.V if (unlikely(!pmd_present(*vmf->pmd))) 4139b0b9b3dfSHugh Dickins ret = VM_FAULT_SIGBUS; 4140ff09d7ecSAneesh Kumar K.V else { 4141ff09d7ecSAneesh Kumar K.V vmf->pte = pte_offset_map_lock(vmf->vma->vm_mm, 4142ff09d7ecSAneesh Kumar K.V vmf->pmd, 4143ff09d7ecSAneesh Kumar K.V vmf->address, 4144ff09d7ecSAneesh Kumar K.V &vmf->ptl); 4145ff09d7ecSAneesh Kumar K.V /* 4146ff09d7ecSAneesh Kumar K.V * Make sure this is not a temporary clearing of pte 4147ff09d7ecSAneesh Kumar K.V * by holding ptl and checking again. A R/M/W update 4148ff09d7ecSAneesh Kumar K.V * of pte involves: take ptl, clearing the pte so that 4149ff09d7ecSAneesh Kumar K.V * we don't have concurrent modification by hardware 4150ff09d7ecSAneesh Kumar K.V * followed by an update. 4151ff09d7ecSAneesh Kumar K.V */ 4152ff09d7ecSAneesh Kumar K.V if (unlikely(pte_none(*vmf->pte))) 4153ff09d7ecSAneesh Kumar K.V ret = VM_FAULT_SIGBUS; 4154ff09d7ecSAneesh Kumar K.V else 4155ff09d7ecSAneesh Kumar K.V ret = VM_FAULT_NOPAGE; 4156ff09d7ecSAneesh Kumar K.V 4157ff09d7ecSAneesh Kumar K.V pte_unmap_unlock(vmf->pte, vmf->ptl); 4158ff09d7ecSAneesh Kumar K.V } 4159ff09d7ecSAneesh Kumar K.V } else if (!(vmf->flags & FAULT_FLAG_WRITE)) 4160b0b9b3dfSHugh Dickins ret = do_read_fault(vmf); 4161b0b9b3dfSHugh Dickins else if (!(vma->vm_flags & VM_SHARED)) 4162b0b9b3dfSHugh Dickins ret = do_cow_fault(vmf); 4163b0b9b3dfSHugh Dickins else 4164b0b9b3dfSHugh Dickins ret = do_shared_fault(vmf); 4165b0b9b3dfSHugh Dickins 4166b0b9b3dfSHugh Dickins /* preallocated pagetable is unused: free it */ 4167b0b9b3dfSHugh Dickins if (vmf->prealloc_pte) { 4168fc8efd2dSJan Stancek pte_free(vm_mm, vmf->prealloc_pte); 41697f2b6ce8STobin C Harding vmf->prealloc_pte = NULL; 4170b0b9b3dfSHugh Dickins } 4171b0b9b3dfSHugh Dickins return ret; 417254cb8821SNick Piggin } 417354cb8821SNick Piggin 4174b19a9939SRashika Kheria static int numa_migrate_prep(struct page *page, struct vm_area_struct *vma, 417504bb2f94SRik van Riel unsigned long addr, int page_nid, 417604bb2f94SRik van Riel int *flags) 41779532fec1SMel Gorman { 41789532fec1SMel Gorman get_page(page); 41799532fec1SMel Gorman 41809532fec1SMel Gorman count_vm_numa_event(NUMA_HINT_FAULTS); 418104bb2f94SRik van Riel if (page_nid == numa_node_id()) { 41829532fec1SMel Gorman count_vm_numa_event(NUMA_HINT_FAULTS_LOCAL); 418304bb2f94SRik van Riel *flags |= TNF_FAULT_LOCAL; 418404bb2f94SRik van Riel } 41859532fec1SMel Gorman 41869532fec1SMel Gorman return mpol_misplaced(page, vma, addr); 41879532fec1SMel Gorman } 41889532fec1SMel Gorman 41892b740303SSouptick Joarder static vm_fault_t do_numa_page(struct vm_fault *vmf) 4190d10e63f2SMel Gorman { 419182b0f8c3SJan Kara struct vm_area_struct *vma = vmf->vma; 41924daae3b4SMel Gorman struct page *page = NULL; 419398fa15f3SAnshuman Khandual int page_nid = NUMA_NO_NODE; 419490572890SPeter Zijlstra int last_cpupid; 4195cbee9f88SPeter Zijlstra int target_nid; 419604a86453SAneesh Kumar K.V pte_t pte, old_pte; 4197288bc549SAneesh Kumar K.V bool was_writable = pte_savedwrite(vmf->orig_pte); 41986688cc05SPeter Zijlstra int flags = 0; 4199d10e63f2SMel Gorman 4200d10e63f2SMel Gorman /* 4201d10e63f2SMel Gorman * The "pte" at this point cannot be used safely without 4202d10e63f2SMel Gorman * validation through pte_unmap_same(). It's of NUMA type but 4203d10e63f2SMel Gorman * the pfn may be screwed if the read is non atomic. 4204d10e63f2SMel Gorman */ 420582b0f8c3SJan Kara vmf->ptl = pte_lockptr(vma->vm_mm, vmf->pmd); 420682b0f8c3SJan Kara spin_lock(vmf->ptl); 4207cee216a6SAneesh Kumar K.V if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) { 420882b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 42094daae3b4SMel Gorman goto out; 42104daae3b4SMel Gorman } 42114daae3b4SMel Gorman 4212b99a342dSHuang Ying /* Get the normal PTE */ 4213b99a342dSHuang Ying old_pte = ptep_get(vmf->pte); 421404a86453SAneesh Kumar K.V pte = pte_modify(old_pte, vma->vm_page_prot); 4215d10e63f2SMel Gorman 421682b0f8c3SJan Kara page = vm_normal_page(vma, vmf->address, pte); 4217b99a342dSHuang Ying if (!page) 4218b99a342dSHuang Ying goto out_map; 4219d10e63f2SMel Gorman 4220e81c4802SKirill A. Shutemov /* TODO: handle PTE-mapped THP */ 4221b99a342dSHuang Ying if (PageCompound(page)) 4222b99a342dSHuang Ying goto out_map; 4223e81c4802SKirill A. Shutemov 42246688cc05SPeter Zijlstra /* 4225bea66fbdSMel Gorman * Avoid grouping on RO pages in general. RO pages shouldn't hurt as 4226bea66fbdSMel Gorman * much anyway since they can be in shared cache state. This misses 4227bea66fbdSMel Gorman * the case where a mapping is writable but the process never writes 4228bea66fbdSMel Gorman * to it but pte_write gets cleared during protection updates and 4229bea66fbdSMel Gorman * pte_dirty has unpredictable behaviour between PTE scan updates, 4230bea66fbdSMel Gorman * background writeback, dirty balancing and application behaviour. 42316688cc05SPeter Zijlstra */ 4232b99a342dSHuang Ying if (!was_writable) 42336688cc05SPeter Zijlstra flags |= TNF_NO_GROUP; 42346688cc05SPeter Zijlstra 4235dabe1d99SRik van Riel /* 4236dabe1d99SRik van Riel * Flag if the page is shared between multiple address spaces. This 4237dabe1d99SRik van Riel * is later used when determining whether to group tasks together 4238dabe1d99SRik van Riel */ 4239dabe1d99SRik van Riel if (page_mapcount(page) > 1 && (vma->vm_flags & VM_SHARED)) 4240dabe1d99SRik van Riel flags |= TNF_SHARED; 4241dabe1d99SRik van Riel 424290572890SPeter Zijlstra last_cpupid = page_cpupid_last(page); 42438191acbdSMel Gorman page_nid = page_to_nid(page); 424482b0f8c3SJan Kara target_nid = numa_migrate_prep(page, vma, vmf->address, page_nid, 4245bae473a4SKirill A. Shutemov &flags); 424698fa15f3SAnshuman Khandual if (target_nid == NUMA_NO_NODE) { 42474daae3b4SMel Gorman put_page(page); 4248b99a342dSHuang Ying goto out_map; 42494daae3b4SMel Gorman } 4250b99a342dSHuang Ying pte_unmap_unlock(vmf->pte, vmf->ptl); 42514daae3b4SMel Gorman 42524daae3b4SMel Gorman /* Migrate to the requested node */ 4253bf90ac19SWang Qing if (migrate_misplaced_page(page, vma, target_nid)) { 42548191acbdSMel Gorman page_nid = target_nid; 42556688cc05SPeter Zijlstra flags |= TNF_MIGRATED; 4256b99a342dSHuang Ying } else { 4257074c2381SMel Gorman flags |= TNF_MIGRATE_FAIL; 4258b99a342dSHuang Ying vmf->pte = pte_offset_map(vmf->pmd, vmf->address); 4259b99a342dSHuang Ying spin_lock(vmf->ptl); 4260b99a342dSHuang Ying if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) { 4261b99a342dSHuang Ying pte_unmap_unlock(vmf->pte, vmf->ptl); 4262b99a342dSHuang Ying goto out; 4263b99a342dSHuang Ying } 4264b99a342dSHuang Ying goto out_map; 4265b99a342dSHuang Ying } 42664daae3b4SMel Gorman 42674daae3b4SMel Gorman out: 426898fa15f3SAnshuman Khandual if (page_nid != NUMA_NO_NODE) 42696688cc05SPeter Zijlstra task_numa_fault(last_cpupid, page_nid, 1, flags); 4270d10e63f2SMel Gorman return 0; 4271b99a342dSHuang Ying out_map: 4272b99a342dSHuang Ying /* 4273b99a342dSHuang Ying * Make it present again, depending on how arch implements 4274b99a342dSHuang Ying * non-accessible ptes, some can allow access by kernel mode. 4275b99a342dSHuang Ying */ 4276b99a342dSHuang Ying old_pte = ptep_modify_prot_start(vma, vmf->address, vmf->pte); 4277b99a342dSHuang Ying pte = pte_modify(old_pte, vma->vm_page_prot); 4278b99a342dSHuang Ying pte = pte_mkyoung(pte); 4279b99a342dSHuang Ying if (was_writable) 4280b99a342dSHuang Ying pte = pte_mkwrite(pte); 4281b99a342dSHuang Ying ptep_modify_prot_commit(vma, vmf->address, vmf->pte, old_pte, pte); 4282b99a342dSHuang Ying update_mmu_cache(vma, vmf->address, vmf->pte); 4283b99a342dSHuang Ying pte_unmap_unlock(vmf->pte, vmf->ptl); 4284b99a342dSHuang Ying goto out; 4285d10e63f2SMel Gorman } 4286d10e63f2SMel Gorman 42872b740303SSouptick Joarder static inline vm_fault_t create_huge_pmd(struct vm_fault *vmf) 4288b96375f7SMatthew Wilcox { 4289f4200391SDave Jiang if (vma_is_anonymous(vmf->vma)) 429082b0f8c3SJan Kara return do_huge_pmd_anonymous_page(vmf); 4291a2d58167SDave Jiang if (vmf->vma->vm_ops->huge_fault) 4292c791ace1SDave Jiang return vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD); 4293b96375f7SMatthew Wilcox return VM_FAULT_FALLBACK; 4294b96375f7SMatthew Wilcox } 4295b96375f7SMatthew Wilcox 4296183f24aaSGeert Uytterhoeven /* `inline' is required to avoid gcc 4.1.2 build error */ 42972b740303SSouptick Joarder static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd) 4298b96375f7SMatthew Wilcox { 4299529b930bSAndrea Arcangeli if (vma_is_anonymous(vmf->vma)) { 4300292924b2SPeter Xu if (userfaultfd_huge_pmd_wp(vmf->vma, orig_pmd)) 4301529b930bSAndrea Arcangeli return handle_userfault(vmf, VM_UFFD_WP); 430282b0f8c3SJan Kara return do_huge_pmd_wp_page(vmf, orig_pmd); 4303529b930bSAndrea Arcangeli } 4304327e9fd4SThomas Hellstrom (VMware) if (vmf->vma->vm_ops->huge_fault) { 4305327e9fd4SThomas Hellstrom (VMware) vm_fault_t ret = vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD); 4306af9e4d5fSKirill A. Shutemov 4307327e9fd4SThomas Hellstrom (VMware) if (!(ret & VM_FAULT_FALLBACK)) 4308327e9fd4SThomas Hellstrom (VMware) return ret; 4309327e9fd4SThomas Hellstrom (VMware) } 4310327e9fd4SThomas Hellstrom (VMware) 4311327e9fd4SThomas Hellstrom (VMware) /* COW or write-notify handled on pte level: split pmd. */ 431282b0f8c3SJan Kara __split_huge_pmd(vmf->vma, vmf->pmd, vmf->address, false, NULL); 4313af9e4d5fSKirill A. Shutemov 4314b96375f7SMatthew Wilcox return VM_FAULT_FALLBACK; 4315b96375f7SMatthew Wilcox } 4316b96375f7SMatthew Wilcox 43172b740303SSouptick Joarder static vm_fault_t create_huge_pud(struct vm_fault *vmf) 4318a00cc7d9SMatthew Wilcox { 4319327e9fd4SThomas Hellstrom (VMware) #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \ 4320327e9fd4SThomas Hellstrom (VMware) defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) 4321a00cc7d9SMatthew Wilcox /* No support for anonymous transparent PUD pages yet */ 4322a00cc7d9SMatthew Wilcox if (vma_is_anonymous(vmf->vma)) 4323327e9fd4SThomas Hellstrom (VMware) goto split; 4324327e9fd4SThomas Hellstrom (VMware) if (vmf->vma->vm_ops->huge_fault) { 4325327e9fd4SThomas Hellstrom (VMware) vm_fault_t ret = vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PUD); 4326327e9fd4SThomas Hellstrom (VMware) 4327327e9fd4SThomas Hellstrom (VMware) if (!(ret & VM_FAULT_FALLBACK)) 4328327e9fd4SThomas Hellstrom (VMware) return ret; 4329327e9fd4SThomas Hellstrom (VMware) } 4330327e9fd4SThomas Hellstrom (VMware) split: 4331327e9fd4SThomas Hellstrom (VMware) /* COW or write-notify not handled on PUD level: split pud.*/ 4332327e9fd4SThomas Hellstrom (VMware) __split_huge_pud(vmf->vma, vmf->pud, vmf->address); 4333a00cc7d9SMatthew Wilcox #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 4334a00cc7d9SMatthew Wilcox return VM_FAULT_FALLBACK; 4335a00cc7d9SMatthew Wilcox } 4336a00cc7d9SMatthew Wilcox 43372b740303SSouptick Joarder static vm_fault_t wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud) 4338a00cc7d9SMatthew Wilcox { 4339a00cc7d9SMatthew Wilcox #ifdef CONFIG_TRANSPARENT_HUGEPAGE 4340a00cc7d9SMatthew Wilcox /* No support for anonymous transparent PUD pages yet */ 4341a00cc7d9SMatthew Wilcox if (vma_is_anonymous(vmf->vma)) 4342a00cc7d9SMatthew Wilcox return VM_FAULT_FALLBACK; 4343a00cc7d9SMatthew Wilcox if (vmf->vma->vm_ops->huge_fault) 4344c791ace1SDave Jiang return vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PUD); 4345a00cc7d9SMatthew Wilcox #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 4346a00cc7d9SMatthew Wilcox return VM_FAULT_FALLBACK; 4347a00cc7d9SMatthew Wilcox } 4348a00cc7d9SMatthew Wilcox 43491da177e4SLinus Torvalds /* 43501da177e4SLinus Torvalds * These routines also need to handle stuff like marking pages dirty 43511da177e4SLinus Torvalds * and/or accessed for architectures that don't do it in hardware (most 43521da177e4SLinus Torvalds * RISC architectures). The early dirtying is also good on the i386. 43531da177e4SLinus Torvalds * 43541da177e4SLinus Torvalds * There is also a hook called "update_mmu_cache()" that architectures 43551da177e4SLinus Torvalds * with external mmu caches can use to update those (ie the Sparc or 43561da177e4SLinus Torvalds * PowerPC hashed page tables that act as extended TLBs). 43571da177e4SLinus Torvalds * 4358c1e8d7c6SMichel Lespinasse * We enter with non-exclusive mmap_lock (to exclude vma changes, but allow 43597267ec00SKirill A. Shutemov * concurrent faults). 43609a95f3cfSPaul Cassella * 4361c1e8d7c6SMichel Lespinasse * The mmap_lock may have been released depending on flags and our return value. 43627267ec00SKirill A. Shutemov * See filemap_fault() and __lock_page_or_retry(). 43631da177e4SLinus Torvalds */ 43642b740303SSouptick Joarder static vm_fault_t handle_pte_fault(struct vm_fault *vmf) 43651da177e4SLinus Torvalds { 43661da177e4SLinus Torvalds pte_t entry; 43671da177e4SLinus Torvalds 436882b0f8c3SJan Kara if (unlikely(pmd_none(*vmf->pmd))) { 43697267ec00SKirill A. Shutemov /* 43707267ec00SKirill A. Shutemov * Leave __pte_alloc() until later: because vm_ops->fault may 43717267ec00SKirill A. Shutemov * want to allocate huge page, and if we expose page table 43727267ec00SKirill A. Shutemov * for an instant, it will be difficult to retract from 43737267ec00SKirill A. Shutemov * concurrent faults and from rmap lookups. 43747267ec00SKirill A. Shutemov */ 437582b0f8c3SJan Kara vmf->pte = NULL; 43767267ec00SKirill A. Shutemov } else { 4377f9ce0be7SKirill A. Shutemov /* 4378f9ce0be7SKirill A. Shutemov * If a huge pmd materialized under us just retry later. Use 4379f9ce0be7SKirill A. Shutemov * pmd_trans_unstable() via pmd_devmap_trans_unstable() instead 4380f9ce0be7SKirill A. Shutemov * of pmd_trans_huge() to ensure the pmd didn't become 4381f9ce0be7SKirill A. Shutemov * pmd_trans_huge under us and then back to pmd_none, as a 4382f9ce0be7SKirill A. Shutemov * result of MADV_DONTNEED running immediately after a huge pmd 4383f9ce0be7SKirill A. Shutemov * fault in a different thread of this mm, in turn leading to a 4384f9ce0be7SKirill A. Shutemov * misleading pmd_trans_huge() retval. All we have to ensure is 4385f9ce0be7SKirill A. Shutemov * that it is a regular pmd that we can walk with 4386f9ce0be7SKirill A. Shutemov * pte_offset_map() and we can do that through an atomic read 4387f9ce0be7SKirill A. Shutemov * in C, which is what pmd_trans_unstable() provides. 4388f9ce0be7SKirill A. Shutemov */ 4389d0f0931dSRoss Zwisler if (pmd_devmap_trans_unstable(vmf->pmd)) 43907267ec00SKirill A. Shutemov return 0; 43917267ec00SKirill A. Shutemov /* 43927267ec00SKirill A. Shutemov * A regular pmd is established and it can't morph into a huge 43937267ec00SKirill A. Shutemov * pmd from under us anymore at this point because we hold the 4394c1e8d7c6SMichel Lespinasse * mmap_lock read mode and khugepaged takes it in write mode. 43957267ec00SKirill A. Shutemov * So now it's safe to run pte_offset_map(). 43967267ec00SKirill A. Shutemov */ 439782b0f8c3SJan Kara vmf->pte = pte_offset_map(vmf->pmd, vmf->address); 43982994302bSJan Kara vmf->orig_pte = *vmf->pte; 43997267ec00SKirill A. Shutemov 4400e37c6982SChristian Borntraeger /* 4401e37c6982SChristian Borntraeger * some architectures can have larger ptes than wordsize, 44027267ec00SKirill A. Shutemov * e.g.ppc44x-defconfig has CONFIG_PTE_64BIT=y and 4403b03a0fe0SPaul E. McKenney * CONFIG_32BIT=y, so READ_ONCE cannot guarantee atomic 4404b03a0fe0SPaul E. McKenney * accesses. The code below just needs a consistent view 4405b03a0fe0SPaul E. McKenney * for the ifs and we later double check anyway with the 44067267ec00SKirill A. Shutemov * ptl lock held. So here a barrier will do. 4407e37c6982SChristian Borntraeger */ 4408e37c6982SChristian Borntraeger barrier(); 44092994302bSJan Kara if (pte_none(vmf->orig_pte)) { 441082b0f8c3SJan Kara pte_unmap(vmf->pte); 441182b0f8c3SJan Kara vmf->pte = NULL; 44127267ec00SKirill A. Shutemov } 44137267ec00SKirill A. Shutemov } 44147267ec00SKirill A. Shutemov 441582b0f8c3SJan Kara if (!vmf->pte) { 441682b0f8c3SJan Kara if (vma_is_anonymous(vmf->vma)) 441782b0f8c3SJan Kara return do_anonymous_page(vmf); 4418b5330628SOleg Nesterov else 441982b0f8c3SJan Kara return do_fault(vmf); 442065500d23SHugh Dickins } 44217267ec00SKirill A. Shutemov 44222994302bSJan Kara if (!pte_present(vmf->orig_pte)) 44232994302bSJan Kara return do_swap_page(vmf); 44241da177e4SLinus Torvalds 44252994302bSJan Kara if (pte_protnone(vmf->orig_pte) && vma_is_accessible(vmf->vma)) 44262994302bSJan Kara return do_numa_page(vmf); 4427d10e63f2SMel Gorman 442882b0f8c3SJan Kara vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); 442982b0f8c3SJan Kara spin_lock(vmf->ptl); 44302994302bSJan Kara entry = vmf->orig_pte; 44317df67697SBibo Mao if (unlikely(!pte_same(*vmf->pte, entry))) { 44327df67697SBibo Mao update_mmu_tlb(vmf->vma, vmf->address, vmf->pte); 44338f4e2101SHugh Dickins goto unlock; 44347df67697SBibo Mao } 443582b0f8c3SJan Kara if (vmf->flags & FAULT_FLAG_WRITE) { 4436f6f37321SLinus Torvalds if (!pte_write(entry)) 44372994302bSJan Kara return do_wp_page(vmf); 44381da177e4SLinus Torvalds entry = pte_mkdirty(entry); 44391da177e4SLinus Torvalds } 44401da177e4SLinus Torvalds entry = pte_mkyoung(entry); 444182b0f8c3SJan Kara if (ptep_set_access_flags(vmf->vma, vmf->address, vmf->pte, entry, 444282b0f8c3SJan Kara vmf->flags & FAULT_FLAG_WRITE)) { 444382b0f8c3SJan Kara update_mmu_cache(vmf->vma, vmf->address, vmf->pte); 44441a44e149SAndrea Arcangeli } else { 4445b7333b58SYang Shi /* Skip spurious TLB flush for retried page fault */ 4446b7333b58SYang Shi if (vmf->flags & FAULT_FLAG_TRIED) 4447b7333b58SYang Shi goto unlock; 44481a44e149SAndrea Arcangeli /* 44491a44e149SAndrea Arcangeli * This is needed only for protection faults but the arch code 44501a44e149SAndrea Arcangeli * is not yet telling us if this is a protection fault or not. 44511a44e149SAndrea Arcangeli * This still avoids useless tlb flushes for .text page faults 44521a44e149SAndrea Arcangeli * with threads. 44531a44e149SAndrea Arcangeli */ 445482b0f8c3SJan Kara if (vmf->flags & FAULT_FLAG_WRITE) 445582b0f8c3SJan Kara flush_tlb_fix_spurious_fault(vmf->vma, vmf->address); 44561a44e149SAndrea Arcangeli } 44578f4e2101SHugh Dickins unlock: 445882b0f8c3SJan Kara pte_unmap_unlock(vmf->pte, vmf->ptl); 445983c54070SNick Piggin return 0; 44601da177e4SLinus Torvalds } 44611da177e4SLinus Torvalds 44621da177e4SLinus Torvalds /* 44631da177e4SLinus Torvalds * By the time we get here, we already hold the mm semaphore 44649a95f3cfSPaul Cassella * 4465c1e8d7c6SMichel Lespinasse * The mmap_lock may have been released depending on flags and our 44669a95f3cfSPaul Cassella * return value. See filemap_fault() and __lock_page_or_retry(). 44671da177e4SLinus Torvalds */ 44682b740303SSouptick Joarder static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma, 44692b740303SSouptick Joarder unsigned long address, unsigned int flags) 44701da177e4SLinus Torvalds { 447182b0f8c3SJan Kara struct vm_fault vmf = { 4472bae473a4SKirill A. Shutemov .vma = vma, 44731a29d85eSJan Kara .address = address & PAGE_MASK, 4474bae473a4SKirill A. Shutemov .flags = flags, 44750721ec8bSJan Kara .pgoff = linear_page_index(vma, address), 4476667240e0SJan Kara .gfp_mask = __get_fault_gfp_mask(vma), 4477bae473a4SKirill A. Shutemov }; 4478fde26bedSAnshuman Khandual unsigned int dirty = flags & FAULT_FLAG_WRITE; 4479dcddffd4SKirill A. Shutemov struct mm_struct *mm = vma->vm_mm; 44801da177e4SLinus Torvalds pgd_t *pgd; 4481c2febafcSKirill A. Shutemov p4d_t *p4d; 44822b740303SSouptick Joarder vm_fault_t ret; 44831da177e4SLinus Torvalds 44841da177e4SLinus Torvalds pgd = pgd_offset(mm, address); 4485c2febafcSKirill A. Shutemov p4d = p4d_alloc(mm, pgd, address); 4486c2febafcSKirill A. Shutemov if (!p4d) 4487c2febafcSKirill A. Shutemov return VM_FAULT_OOM; 4488a00cc7d9SMatthew Wilcox 4489c2febafcSKirill A. Shutemov vmf.pud = pud_alloc(mm, p4d, address); 4490a00cc7d9SMatthew Wilcox if (!vmf.pud) 4491c74df32cSHugh Dickins return VM_FAULT_OOM; 4492625110b5SThomas Hellstrom retry_pud: 44937635d9cbSMichal Hocko if (pud_none(*vmf.pud) && __transparent_hugepage_enabled(vma)) { 4494a00cc7d9SMatthew Wilcox ret = create_huge_pud(&vmf); 4495a00cc7d9SMatthew Wilcox if (!(ret & VM_FAULT_FALLBACK)) 4496a00cc7d9SMatthew Wilcox return ret; 4497a00cc7d9SMatthew Wilcox } else { 4498a00cc7d9SMatthew Wilcox pud_t orig_pud = *vmf.pud; 4499a00cc7d9SMatthew Wilcox 4500a00cc7d9SMatthew Wilcox barrier(); 4501a00cc7d9SMatthew Wilcox if (pud_trans_huge(orig_pud) || pud_devmap(orig_pud)) { 4502a00cc7d9SMatthew Wilcox 4503a00cc7d9SMatthew Wilcox /* NUMA case for anonymous PUDs would go here */ 4504a00cc7d9SMatthew Wilcox 4505f6f37321SLinus Torvalds if (dirty && !pud_write(orig_pud)) { 4506a00cc7d9SMatthew Wilcox ret = wp_huge_pud(&vmf, orig_pud); 4507a00cc7d9SMatthew Wilcox if (!(ret & VM_FAULT_FALLBACK)) 4508a00cc7d9SMatthew Wilcox return ret; 4509a00cc7d9SMatthew Wilcox } else { 4510a00cc7d9SMatthew Wilcox huge_pud_set_accessed(&vmf, orig_pud); 4511a00cc7d9SMatthew Wilcox return 0; 4512a00cc7d9SMatthew Wilcox } 4513a00cc7d9SMatthew Wilcox } 4514a00cc7d9SMatthew Wilcox } 4515a00cc7d9SMatthew Wilcox 4516a00cc7d9SMatthew Wilcox vmf.pmd = pmd_alloc(mm, vmf.pud, address); 451782b0f8c3SJan Kara if (!vmf.pmd) 4518c74df32cSHugh Dickins return VM_FAULT_OOM; 4519625110b5SThomas Hellstrom 4520625110b5SThomas Hellstrom /* Huge pud page fault raced with pmd_alloc? */ 4521625110b5SThomas Hellstrom if (pud_trans_unstable(vmf.pud)) 4522625110b5SThomas Hellstrom goto retry_pud; 4523625110b5SThomas Hellstrom 45247635d9cbSMichal Hocko if (pmd_none(*vmf.pmd) && __transparent_hugepage_enabled(vma)) { 4525a2d58167SDave Jiang ret = create_huge_pmd(&vmf); 4526c0292554SKirill A. Shutemov if (!(ret & VM_FAULT_FALLBACK)) 4527c0292554SKirill A. Shutemov return ret; 452871e3aac0SAndrea Arcangeli } else { 452982b0f8c3SJan Kara pmd_t orig_pmd = *vmf.pmd; 45301f1d06c3SDavid Rientjes 453171e3aac0SAndrea Arcangeli barrier(); 453284c3fc4eSZi Yan if (unlikely(is_swap_pmd(orig_pmd))) { 453384c3fc4eSZi Yan VM_BUG_ON(thp_migration_supported() && 453484c3fc4eSZi Yan !is_pmd_migration_entry(orig_pmd)); 453584c3fc4eSZi Yan if (is_pmd_migration_entry(orig_pmd)) 453684c3fc4eSZi Yan pmd_migration_entry_wait(mm, vmf.pmd); 453784c3fc4eSZi Yan return 0; 453884c3fc4eSZi Yan } 45395c7fb56eSDan Williams if (pmd_trans_huge(orig_pmd) || pmd_devmap(orig_pmd)) { 454038e08854SLorenzo Stoakes if (pmd_protnone(orig_pmd) && vma_is_accessible(vma)) 454182b0f8c3SJan Kara return do_huge_pmd_numa_page(&vmf, orig_pmd); 4542d10e63f2SMel Gorman 4543f6f37321SLinus Torvalds if (dirty && !pmd_write(orig_pmd)) { 454482b0f8c3SJan Kara ret = wp_huge_pmd(&vmf, orig_pmd); 45459845cbbdSKirill A. Shutemov if (!(ret & VM_FAULT_FALLBACK)) 45461f1d06c3SDavid Rientjes return ret; 4547a1dd450bSWill Deacon } else { 454882b0f8c3SJan Kara huge_pmd_set_accessed(&vmf, orig_pmd); 454971e3aac0SAndrea Arcangeli return 0; 455071e3aac0SAndrea Arcangeli } 455171e3aac0SAndrea Arcangeli } 45529845cbbdSKirill A. Shutemov } 455371e3aac0SAndrea Arcangeli 455482b0f8c3SJan Kara return handle_pte_fault(&vmf); 45551da177e4SLinus Torvalds } 45561da177e4SLinus Torvalds 4557bce617edSPeter Xu /** 4558f0953a1bSIngo Molnar * mm_account_fault - Do page fault accounting 4559bce617edSPeter Xu * 4560bce617edSPeter Xu * @regs: the pt_regs struct pointer. When set to NULL, will skip accounting 4561bce617edSPeter Xu * of perf event counters, but we'll still do the per-task accounting to 4562bce617edSPeter Xu * the task who triggered this page fault. 4563bce617edSPeter Xu * @address: the faulted address. 4564bce617edSPeter Xu * @flags: the fault flags. 4565bce617edSPeter Xu * @ret: the fault retcode. 4566bce617edSPeter Xu * 4567f0953a1bSIngo Molnar * This will take care of most of the page fault accounting. Meanwhile, it 4568bce617edSPeter Xu * will also include the PERF_COUNT_SW_PAGE_FAULTS_[MAJ|MIN] perf counter 4569f0953a1bSIngo Molnar * updates. However, note that the handling of PERF_COUNT_SW_PAGE_FAULTS should 4570bce617edSPeter Xu * still be in per-arch page fault handlers at the entry of page fault. 4571bce617edSPeter Xu */ 4572bce617edSPeter Xu static inline void mm_account_fault(struct pt_regs *regs, 4573bce617edSPeter Xu unsigned long address, unsigned int flags, 4574bce617edSPeter Xu vm_fault_t ret) 4575bce617edSPeter Xu { 4576bce617edSPeter Xu bool major; 4577bce617edSPeter Xu 4578bce617edSPeter Xu /* 4579bce617edSPeter Xu * We don't do accounting for some specific faults: 4580bce617edSPeter Xu * 4581bce617edSPeter Xu * - Unsuccessful faults (e.g. when the address wasn't valid). That 4582bce617edSPeter Xu * includes arch_vma_access_permitted() failing before reaching here. 4583bce617edSPeter Xu * So this is not a "this many hardware page faults" counter. We 4584bce617edSPeter Xu * should use the hw profiling for that. 4585bce617edSPeter Xu * 4586bce617edSPeter Xu * - Incomplete faults (VM_FAULT_RETRY). They will only be counted 4587bce617edSPeter Xu * once they're completed. 4588bce617edSPeter Xu */ 4589bce617edSPeter Xu if (ret & (VM_FAULT_ERROR | VM_FAULT_RETRY)) 4590bce617edSPeter Xu return; 4591bce617edSPeter Xu 4592bce617edSPeter Xu /* 4593bce617edSPeter Xu * We define the fault as a major fault when the final successful fault 4594bce617edSPeter Xu * is VM_FAULT_MAJOR, or if it retried (which implies that we couldn't 4595bce617edSPeter Xu * handle it immediately previously). 4596bce617edSPeter Xu */ 4597bce617edSPeter Xu major = (ret & VM_FAULT_MAJOR) || (flags & FAULT_FLAG_TRIED); 4598bce617edSPeter Xu 4599a2beb5f1SPeter Xu if (major) 4600a2beb5f1SPeter Xu current->maj_flt++; 4601a2beb5f1SPeter Xu else 4602a2beb5f1SPeter Xu current->min_flt++; 4603a2beb5f1SPeter Xu 4604bce617edSPeter Xu /* 4605a2beb5f1SPeter Xu * If the fault is done for GUP, regs will be NULL. We only do the 4606a2beb5f1SPeter Xu * accounting for the per thread fault counters who triggered the 4607a2beb5f1SPeter Xu * fault, and we skip the perf event updates. 4608bce617edSPeter Xu */ 4609bce617edSPeter Xu if (!regs) 4610bce617edSPeter Xu return; 4611bce617edSPeter Xu 4612a2beb5f1SPeter Xu if (major) 4613bce617edSPeter Xu perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs, address); 4614a2beb5f1SPeter Xu else 4615bce617edSPeter Xu perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, address); 4616bce617edSPeter Xu } 4617bce617edSPeter Xu 46189a95f3cfSPaul Cassella /* 46199a95f3cfSPaul Cassella * By the time we get here, we already hold the mm semaphore 46209a95f3cfSPaul Cassella * 4621c1e8d7c6SMichel Lespinasse * The mmap_lock may have been released depending on flags and our 46229a95f3cfSPaul Cassella * return value. See filemap_fault() and __lock_page_or_retry(). 46239a95f3cfSPaul Cassella */ 46242b740303SSouptick Joarder vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address, 4625bce617edSPeter Xu unsigned int flags, struct pt_regs *regs) 4626519e5247SJohannes Weiner { 46272b740303SSouptick Joarder vm_fault_t ret; 4628519e5247SJohannes Weiner 4629519e5247SJohannes Weiner __set_current_state(TASK_RUNNING); 4630519e5247SJohannes Weiner 4631519e5247SJohannes Weiner count_vm_event(PGFAULT); 46322262185cSRoman Gushchin count_memcg_event_mm(vma->vm_mm, PGFAULT); 4633519e5247SJohannes Weiner 4634519e5247SJohannes Weiner /* do counter updates before entering really critical section. */ 4635519e5247SJohannes Weiner check_sync_rss_stat(current); 4636519e5247SJohannes Weiner 4637de0c799bSLaurent Dufour if (!arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, 4638de0c799bSLaurent Dufour flags & FAULT_FLAG_INSTRUCTION, 4639de0c799bSLaurent Dufour flags & FAULT_FLAG_REMOTE)) 4640de0c799bSLaurent Dufour return VM_FAULT_SIGSEGV; 4641de0c799bSLaurent Dufour 4642519e5247SJohannes Weiner /* 4643519e5247SJohannes Weiner * Enable the memcg OOM handling for faults triggered in user 4644519e5247SJohannes Weiner * space. Kernel faults are handled more gracefully. 4645519e5247SJohannes Weiner */ 4646519e5247SJohannes Weiner if (flags & FAULT_FLAG_USER) 464729ef680aSMichal Hocko mem_cgroup_enter_user_fault(); 4648519e5247SJohannes Weiner 4649bae473a4SKirill A. Shutemov if (unlikely(is_vm_hugetlb_page(vma))) 4650bae473a4SKirill A. Shutemov ret = hugetlb_fault(vma->vm_mm, vma, address, flags); 4651bae473a4SKirill A. Shutemov else 4652dcddffd4SKirill A. Shutemov ret = __handle_mm_fault(vma, address, flags); 4653519e5247SJohannes Weiner 465449426420SJohannes Weiner if (flags & FAULT_FLAG_USER) { 465529ef680aSMichal Hocko mem_cgroup_exit_user_fault(); 465649426420SJohannes Weiner /* 465749426420SJohannes Weiner * The task may have entered a memcg OOM situation but 465849426420SJohannes Weiner * if the allocation error was handled gracefully (no 465949426420SJohannes Weiner * VM_FAULT_OOM), there is no need to kill anything. 466049426420SJohannes Weiner * Just clean up the OOM state peacefully. 466149426420SJohannes Weiner */ 466249426420SJohannes Weiner if (task_in_memcg_oom(current) && !(ret & VM_FAULT_OOM)) 466349426420SJohannes Weiner mem_cgroup_oom_synchronize(false); 466449426420SJohannes Weiner } 46653812c8c8SJohannes Weiner 4666bce617edSPeter Xu mm_account_fault(regs, address, flags, ret); 4667bce617edSPeter Xu 4668519e5247SJohannes Weiner return ret; 4669519e5247SJohannes Weiner } 4670e1d6d01aSJesse Barnes EXPORT_SYMBOL_GPL(handle_mm_fault); 4671519e5247SJohannes Weiner 467290eceff1SKirill A. Shutemov #ifndef __PAGETABLE_P4D_FOLDED 467390eceff1SKirill A. Shutemov /* 467490eceff1SKirill A. Shutemov * Allocate p4d page table. 467590eceff1SKirill A. Shutemov * We've already handled the fast-path in-line. 467690eceff1SKirill A. Shutemov */ 467790eceff1SKirill A. Shutemov int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) 467890eceff1SKirill A. Shutemov { 467990eceff1SKirill A. Shutemov p4d_t *new = p4d_alloc_one(mm, address); 468090eceff1SKirill A. Shutemov if (!new) 468190eceff1SKirill A. Shutemov return -ENOMEM; 468290eceff1SKirill A. Shutemov 468390eceff1SKirill A. Shutemov smp_wmb(); /* See comment in __pte_alloc */ 468490eceff1SKirill A. Shutemov 468590eceff1SKirill A. Shutemov spin_lock(&mm->page_table_lock); 468690eceff1SKirill A. Shutemov if (pgd_present(*pgd)) /* Another has populated it */ 468790eceff1SKirill A. Shutemov p4d_free(mm, new); 468890eceff1SKirill A. Shutemov else 468990eceff1SKirill A. Shutemov pgd_populate(mm, pgd, new); 469090eceff1SKirill A. Shutemov spin_unlock(&mm->page_table_lock); 469190eceff1SKirill A. Shutemov return 0; 469290eceff1SKirill A. Shutemov } 469390eceff1SKirill A. Shutemov #endif /* __PAGETABLE_P4D_FOLDED */ 469490eceff1SKirill A. Shutemov 46951da177e4SLinus Torvalds #ifndef __PAGETABLE_PUD_FOLDED 46961da177e4SLinus Torvalds /* 46971da177e4SLinus Torvalds * Allocate page upper directory. 4698872fec16SHugh Dickins * We've already handled the fast-path in-line. 46991da177e4SLinus Torvalds */ 4700c2febafcSKirill A. Shutemov int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address) 47011da177e4SLinus Torvalds { 4702c74df32cSHugh Dickins pud_t *new = pud_alloc_one(mm, address); 4703c74df32cSHugh Dickins if (!new) 47041bb3630eSHugh Dickins return -ENOMEM; 47051da177e4SLinus Torvalds 4706362a61adSNick Piggin smp_wmb(); /* See comment in __pte_alloc */ 4707362a61adSNick Piggin 4708872fec16SHugh Dickins spin_lock(&mm->page_table_lock); 4709b4e98d9aSKirill A. Shutemov if (!p4d_present(*p4d)) { 4710b4e98d9aSKirill A. Shutemov mm_inc_nr_puds(mm); 4711c2febafcSKirill A. Shutemov p4d_populate(mm, p4d, new); 4712b4e98d9aSKirill A. Shutemov } else /* Another has populated it */ 4713c2febafcSKirill A. Shutemov pud_free(mm, new); 4714872fec16SHugh Dickins spin_unlock(&mm->page_table_lock); 47151bb3630eSHugh Dickins return 0; 47161da177e4SLinus Torvalds } 47171da177e4SLinus Torvalds #endif /* __PAGETABLE_PUD_FOLDED */ 47181da177e4SLinus Torvalds 47191da177e4SLinus Torvalds #ifndef __PAGETABLE_PMD_FOLDED 47201da177e4SLinus Torvalds /* 47211da177e4SLinus Torvalds * Allocate page middle directory. 4722872fec16SHugh Dickins * We've already handled the fast-path in-line. 47231da177e4SLinus Torvalds */ 47241bb3630eSHugh Dickins int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) 47251da177e4SLinus Torvalds { 4726a00cc7d9SMatthew Wilcox spinlock_t *ptl; 4727c74df32cSHugh Dickins pmd_t *new = pmd_alloc_one(mm, address); 4728c74df32cSHugh Dickins if (!new) 47291bb3630eSHugh Dickins return -ENOMEM; 47301da177e4SLinus Torvalds 4731362a61adSNick Piggin smp_wmb(); /* See comment in __pte_alloc */ 4732362a61adSNick Piggin 4733a00cc7d9SMatthew Wilcox ptl = pud_lock(mm, pud); 4734dc6c9a35SKirill A. Shutemov if (!pud_present(*pud)) { 4735dc6c9a35SKirill A. Shutemov mm_inc_nr_pmds(mm); 47361da177e4SLinus Torvalds pud_populate(mm, pud, new); 4737dc6c9a35SKirill A. Shutemov } else /* Another has populated it */ 47385e541973SBenjamin Herrenschmidt pmd_free(mm, new); 4739a00cc7d9SMatthew Wilcox spin_unlock(ptl); 47401bb3630eSHugh Dickins return 0; 47411da177e4SLinus Torvalds } 47421da177e4SLinus Torvalds #endif /* __PAGETABLE_PMD_FOLDED */ 47431da177e4SLinus Torvalds 47449fd6dad1SPaolo Bonzini int follow_invalidate_pte(struct mm_struct *mm, unsigned long address, 47459fd6dad1SPaolo Bonzini struct mmu_notifier_range *range, pte_t **ptepp, 47469fd6dad1SPaolo Bonzini pmd_t **pmdpp, spinlock_t **ptlp) 4747f8ad0f49SJohannes Weiner { 4748f8ad0f49SJohannes Weiner pgd_t *pgd; 4749c2febafcSKirill A. Shutemov p4d_t *p4d; 4750f8ad0f49SJohannes Weiner pud_t *pud; 4751f8ad0f49SJohannes Weiner pmd_t *pmd; 4752f8ad0f49SJohannes Weiner pte_t *ptep; 4753f8ad0f49SJohannes Weiner 4754f8ad0f49SJohannes Weiner pgd = pgd_offset(mm, address); 4755f8ad0f49SJohannes Weiner if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) 4756f8ad0f49SJohannes Weiner goto out; 4757f8ad0f49SJohannes Weiner 4758c2febafcSKirill A. Shutemov p4d = p4d_offset(pgd, address); 4759c2febafcSKirill A. Shutemov if (p4d_none(*p4d) || unlikely(p4d_bad(*p4d))) 4760c2febafcSKirill A. Shutemov goto out; 4761c2febafcSKirill A. Shutemov 4762c2febafcSKirill A. Shutemov pud = pud_offset(p4d, address); 4763f8ad0f49SJohannes Weiner if (pud_none(*pud) || unlikely(pud_bad(*pud))) 4764f8ad0f49SJohannes Weiner goto out; 4765f8ad0f49SJohannes Weiner 4766f8ad0f49SJohannes Weiner pmd = pmd_offset(pud, address); 4767f66055abSAndrea Arcangeli VM_BUG_ON(pmd_trans_huge(*pmd)); 476809796395SRoss Zwisler 476909796395SRoss Zwisler if (pmd_huge(*pmd)) { 477009796395SRoss Zwisler if (!pmdpp) 4771f8ad0f49SJohannes Weiner goto out; 4772f8ad0f49SJohannes Weiner 4773ac46d4f3SJérôme Glisse if (range) { 47747269f999SJérôme Glisse mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0, 47756f4f13e8SJérôme Glisse NULL, mm, address & PMD_MASK, 4776ac46d4f3SJérôme Glisse (address & PMD_MASK) + PMD_SIZE); 4777ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(range); 4778a4d1a885SJérôme Glisse } 477909796395SRoss Zwisler *ptlp = pmd_lock(mm, pmd); 478009796395SRoss Zwisler if (pmd_huge(*pmd)) { 478109796395SRoss Zwisler *pmdpp = pmd; 478209796395SRoss Zwisler return 0; 478309796395SRoss Zwisler } 478409796395SRoss Zwisler spin_unlock(*ptlp); 4785ac46d4f3SJérôme Glisse if (range) 4786ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(range); 478709796395SRoss Zwisler } 478809796395SRoss Zwisler 478909796395SRoss Zwisler if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) 4790f8ad0f49SJohannes Weiner goto out; 4791f8ad0f49SJohannes Weiner 4792ac46d4f3SJérôme Glisse if (range) { 47937269f999SJérôme Glisse mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0, NULL, mm, 47946f4f13e8SJérôme Glisse address & PAGE_MASK, 47951ed7293aSMatthew Wilcox (address & PAGE_MASK) + PAGE_SIZE); 4796ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_start(range); 4797a4d1a885SJérôme Glisse } 4798f8ad0f49SJohannes Weiner ptep = pte_offset_map_lock(mm, pmd, address, ptlp); 4799f8ad0f49SJohannes Weiner if (!pte_present(*ptep)) 4800f8ad0f49SJohannes Weiner goto unlock; 4801f8ad0f49SJohannes Weiner *ptepp = ptep; 4802f8ad0f49SJohannes Weiner return 0; 4803f8ad0f49SJohannes Weiner unlock: 4804f8ad0f49SJohannes Weiner pte_unmap_unlock(ptep, *ptlp); 4805ac46d4f3SJérôme Glisse if (range) 4806ac46d4f3SJérôme Glisse mmu_notifier_invalidate_range_end(range); 4807f8ad0f49SJohannes Weiner out: 4808f8ad0f49SJohannes Weiner return -EINVAL; 4809f8ad0f49SJohannes Weiner } 4810f8ad0f49SJohannes Weiner 48113b6748e2SJohannes Weiner /** 48129fd6dad1SPaolo Bonzini * follow_pte - look up PTE at a user virtual address 48139fd6dad1SPaolo Bonzini * @mm: the mm_struct of the target address space 48149fd6dad1SPaolo Bonzini * @address: user virtual address 48159fd6dad1SPaolo Bonzini * @ptepp: location to store found PTE 48169fd6dad1SPaolo Bonzini * @ptlp: location to store the lock for the PTE 48179fd6dad1SPaolo Bonzini * 48189fd6dad1SPaolo Bonzini * On a successful return, the pointer to the PTE is stored in @ptepp; 48199fd6dad1SPaolo Bonzini * the corresponding lock is taken and its location is stored in @ptlp. 48209fd6dad1SPaolo Bonzini * The contents of the PTE are only stable until @ptlp is released; 48219fd6dad1SPaolo Bonzini * any further use, if any, must be protected against invalidation 48229fd6dad1SPaolo Bonzini * with MMU notifiers. 48239fd6dad1SPaolo Bonzini * 48249fd6dad1SPaolo Bonzini * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore 48259fd6dad1SPaolo Bonzini * should be taken for read. 48269fd6dad1SPaolo Bonzini * 48279fd6dad1SPaolo Bonzini * KVM uses this function. While it is arguably less bad than ``follow_pfn``, 48289fd6dad1SPaolo Bonzini * it is not a good general-purpose API. 48299fd6dad1SPaolo Bonzini * 48309fd6dad1SPaolo Bonzini * Return: zero on success, -ve otherwise. 48319fd6dad1SPaolo Bonzini */ 48329fd6dad1SPaolo Bonzini int follow_pte(struct mm_struct *mm, unsigned long address, 48339fd6dad1SPaolo Bonzini pte_t **ptepp, spinlock_t **ptlp) 48349fd6dad1SPaolo Bonzini { 48359fd6dad1SPaolo Bonzini return follow_invalidate_pte(mm, address, NULL, ptepp, NULL, ptlp); 48369fd6dad1SPaolo Bonzini } 48379fd6dad1SPaolo Bonzini EXPORT_SYMBOL_GPL(follow_pte); 48389fd6dad1SPaolo Bonzini 48399fd6dad1SPaolo Bonzini /** 48403b6748e2SJohannes Weiner * follow_pfn - look up PFN at a user virtual address 48413b6748e2SJohannes Weiner * @vma: memory mapping 48423b6748e2SJohannes Weiner * @address: user virtual address 48433b6748e2SJohannes Weiner * @pfn: location to store found PFN 48443b6748e2SJohannes Weiner * 48453b6748e2SJohannes Weiner * Only IO mappings and raw PFN mappings are allowed. 48463b6748e2SJohannes Weiner * 48479fd6dad1SPaolo Bonzini * This function does not allow the caller to read the permissions 48489fd6dad1SPaolo Bonzini * of the PTE. Do not use it. 48499fd6dad1SPaolo Bonzini * 4850a862f68aSMike Rapoport * Return: zero and the pfn at @pfn on success, -ve otherwise. 48513b6748e2SJohannes Weiner */ 48523b6748e2SJohannes Weiner int follow_pfn(struct vm_area_struct *vma, unsigned long address, 48533b6748e2SJohannes Weiner unsigned long *pfn) 48543b6748e2SJohannes Weiner { 48553b6748e2SJohannes Weiner int ret = -EINVAL; 48563b6748e2SJohannes Weiner spinlock_t *ptl; 48573b6748e2SJohannes Weiner pte_t *ptep; 48583b6748e2SJohannes Weiner 48593b6748e2SJohannes Weiner if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 48603b6748e2SJohannes Weiner return ret; 48613b6748e2SJohannes Weiner 48629fd6dad1SPaolo Bonzini ret = follow_pte(vma->vm_mm, address, &ptep, &ptl); 48633b6748e2SJohannes Weiner if (ret) 48643b6748e2SJohannes Weiner return ret; 48653b6748e2SJohannes Weiner *pfn = pte_pfn(*ptep); 48663b6748e2SJohannes Weiner pte_unmap_unlock(ptep, ptl); 48673b6748e2SJohannes Weiner return 0; 48683b6748e2SJohannes Weiner } 48693b6748e2SJohannes Weiner EXPORT_SYMBOL(follow_pfn); 48703b6748e2SJohannes Weiner 487128b2ee20SRik van Riel #ifdef CONFIG_HAVE_IOREMAP_PROT 4872d87fe660Svenkatesh.pallipadi@intel.com int follow_phys(struct vm_area_struct *vma, 487328b2ee20SRik van Riel unsigned long address, unsigned int flags, 4874d87fe660Svenkatesh.pallipadi@intel.com unsigned long *prot, resource_size_t *phys) 487528b2ee20SRik van Riel { 487603668a4dSJohannes Weiner int ret = -EINVAL; 487728b2ee20SRik van Riel pte_t *ptep, pte; 487828b2ee20SRik van Riel spinlock_t *ptl; 487928b2ee20SRik van Riel 4880d87fe660Svenkatesh.pallipadi@intel.com if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 4881d87fe660Svenkatesh.pallipadi@intel.com goto out; 488228b2ee20SRik van Riel 48839fd6dad1SPaolo Bonzini if (follow_pte(vma->vm_mm, address, &ptep, &ptl)) 4884d87fe660Svenkatesh.pallipadi@intel.com goto out; 488528b2ee20SRik van Riel pte = *ptep; 488603668a4dSJohannes Weiner 4887f6f37321SLinus Torvalds if ((flags & FOLL_WRITE) && !pte_write(pte)) 488828b2ee20SRik van Riel goto unlock; 488928b2ee20SRik van Riel 489028b2ee20SRik van Riel *prot = pgprot_val(pte_pgprot(pte)); 489103668a4dSJohannes Weiner *phys = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT; 489228b2ee20SRik van Riel 489303668a4dSJohannes Weiner ret = 0; 489428b2ee20SRik van Riel unlock: 489528b2ee20SRik van Riel pte_unmap_unlock(ptep, ptl); 489628b2ee20SRik van Riel out: 4897d87fe660Svenkatesh.pallipadi@intel.com return ret; 489828b2ee20SRik van Riel } 489928b2ee20SRik van Riel 490096667f8aSDaniel Vetter /** 490196667f8aSDaniel Vetter * generic_access_phys - generic implementation for iomem mmap access 490296667f8aSDaniel Vetter * @vma: the vma to access 4903f0953a1bSIngo Molnar * @addr: userspace address, not relative offset within @vma 490496667f8aSDaniel Vetter * @buf: buffer to read/write 490596667f8aSDaniel Vetter * @len: length of transfer 490696667f8aSDaniel Vetter * @write: set to FOLL_WRITE when writing, otherwise reading 490796667f8aSDaniel Vetter * 490896667f8aSDaniel Vetter * This is a generic implementation for &vm_operations_struct.access for an 490996667f8aSDaniel Vetter * iomem mapping. This callback is used by access_process_vm() when the @vma is 491096667f8aSDaniel Vetter * not page based. 491196667f8aSDaniel Vetter */ 491228b2ee20SRik van Riel int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, 491328b2ee20SRik van Riel void *buf, int len, int write) 491428b2ee20SRik van Riel { 491528b2ee20SRik van Riel resource_size_t phys_addr; 491628b2ee20SRik van Riel unsigned long prot = 0; 49172bc7273bSKOSAKI Motohiro void __iomem *maddr; 491896667f8aSDaniel Vetter pte_t *ptep, pte; 491996667f8aSDaniel Vetter spinlock_t *ptl; 492096667f8aSDaniel Vetter int offset = offset_in_page(addr); 492196667f8aSDaniel Vetter int ret = -EINVAL; 492228b2ee20SRik van Riel 492396667f8aSDaniel Vetter if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 492496667f8aSDaniel Vetter return -EINVAL; 492596667f8aSDaniel Vetter 492696667f8aSDaniel Vetter retry: 4927e913a8cdSLinus Torvalds if (follow_pte(vma->vm_mm, addr, &ptep, &ptl)) 492896667f8aSDaniel Vetter return -EINVAL; 492996667f8aSDaniel Vetter pte = *ptep; 493096667f8aSDaniel Vetter pte_unmap_unlock(ptep, ptl); 493196667f8aSDaniel Vetter 493296667f8aSDaniel Vetter prot = pgprot_val(pte_pgprot(pte)); 493396667f8aSDaniel Vetter phys_addr = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT; 493496667f8aSDaniel Vetter 493596667f8aSDaniel Vetter if ((write & FOLL_WRITE) && !pte_write(pte)) 493628b2ee20SRik van Riel return -EINVAL; 493728b2ee20SRik van Riel 49389cb12d7bSGrazvydas Ignotas maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot); 493924eee1e4Sjie@chenjie6@huwei.com if (!maddr) 494024eee1e4Sjie@chenjie6@huwei.com return -ENOMEM; 494124eee1e4Sjie@chenjie6@huwei.com 4942e913a8cdSLinus Torvalds if (follow_pte(vma->vm_mm, addr, &ptep, &ptl)) 494396667f8aSDaniel Vetter goto out_unmap; 494496667f8aSDaniel Vetter 494596667f8aSDaniel Vetter if (!pte_same(pte, *ptep)) { 494696667f8aSDaniel Vetter pte_unmap_unlock(ptep, ptl); 494796667f8aSDaniel Vetter iounmap(maddr); 494896667f8aSDaniel Vetter 494996667f8aSDaniel Vetter goto retry; 495096667f8aSDaniel Vetter } 495196667f8aSDaniel Vetter 495228b2ee20SRik van Riel if (write) 495328b2ee20SRik van Riel memcpy_toio(maddr + offset, buf, len); 495428b2ee20SRik van Riel else 495528b2ee20SRik van Riel memcpy_fromio(buf, maddr + offset, len); 495696667f8aSDaniel Vetter ret = len; 495796667f8aSDaniel Vetter pte_unmap_unlock(ptep, ptl); 495896667f8aSDaniel Vetter out_unmap: 495928b2ee20SRik van Riel iounmap(maddr); 496028b2ee20SRik van Riel 496196667f8aSDaniel Vetter return ret; 496228b2ee20SRik van Riel } 49635a73633eSUwe Kleine-König EXPORT_SYMBOL_GPL(generic_access_phys); 496428b2ee20SRik van Riel #endif 496528b2ee20SRik van Riel 49660ec76a11SDavid Howells /* 4967d3f5ffcaSJohn Hubbard * Access another process' address space as given in mm. 49680ec76a11SDavid Howells */ 4969d3f5ffcaSJohn Hubbard int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf, 4970d3f5ffcaSJohn Hubbard int len, unsigned int gup_flags) 49710ec76a11SDavid Howells { 49720ec76a11SDavid Howells struct vm_area_struct *vma; 49730ec76a11SDavid Howells void *old_buf = buf; 4974442486ecSLorenzo Stoakes int write = gup_flags & FOLL_WRITE; 49750ec76a11SDavid Howells 4976d8ed45c5SMichel Lespinasse if (mmap_read_lock_killable(mm)) 49771e426fe2SKonstantin Khlebnikov return 0; 49781e426fe2SKonstantin Khlebnikov 4979183ff22bSSimon Arlott /* ignore errors, just check how much was successfully transferred */ 49800ec76a11SDavid Howells while (len) { 49810ec76a11SDavid Howells int bytes, ret, offset; 49820ec76a11SDavid Howells void *maddr; 498328b2ee20SRik van Riel struct page *page = NULL; 49840ec76a11SDavid Howells 498564019a2eSPeter Xu ret = get_user_pages_remote(mm, addr, 1, 49865b56d49fSLorenzo Stoakes gup_flags, &page, &vma, NULL); 498728b2ee20SRik van Riel if (ret <= 0) { 4988dbffcd03SRik van Riel #ifndef CONFIG_HAVE_IOREMAP_PROT 4989dbffcd03SRik van Riel break; 4990dbffcd03SRik van Riel #else 499128b2ee20SRik van Riel /* 499228b2ee20SRik van Riel * Check if this is a VM_IO | VM_PFNMAP VMA, which 499328b2ee20SRik van Riel * we can access using slightly different code. 499428b2ee20SRik van Riel */ 499528b2ee20SRik van Riel vma = find_vma(mm, addr); 4996fe936dfcSMichael Ellerman if (!vma || vma->vm_start > addr) 49970ec76a11SDavid Howells break; 499828b2ee20SRik van Riel if (vma->vm_ops && vma->vm_ops->access) 499928b2ee20SRik van Riel ret = vma->vm_ops->access(vma, addr, buf, 500028b2ee20SRik van Riel len, write); 500128b2ee20SRik van Riel if (ret <= 0) 500228b2ee20SRik van Riel break; 500328b2ee20SRik van Riel bytes = ret; 5004dbffcd03SRik van Riel #endif 500528b2ee20SRik van Riel } else { 50060ec76a11SDavid Howells bytes = len; 50070ec76a11SDavid Howells offset = addr & (PAGE_SIZE-1); 50080ec76a11SDavid Howells if (bytes > PAGE_SIZE-offset) 50090ec76a11SDavid Howells bytes = PAGE_SIZE-offset; 50100ec76a11SDavid Howells 50110ec76a11SDavid Howells maddr = kmap(page); 50120ec76a11SDavid Howells if (write) { 50130ec76a11SDavid Howells copy_to_user_page(vma, page, addr, 50140ec76a11SDavid Howells maddr + offset, buf, bytes); 50150ec76a11SDavid Howells set_page_dirty_lock(page); 50160ec76a11SDavid Howells } else { 50170ec76a11SDavid Howells copy_from_user_page(vma, page, addr, 50180ec76a11SDavid Howells buf, maddr + offset, bytes); 50190ec76a11SDavid Howells } 50200ec76a11SDavid Howells kunmap(page); 502109cbfeafSKirill A. Shutemov put_page(page); 502228b2ee20SRik van Riel } 50230ec76a11SDavid Howells len -= bytes; 50240ec76a11SDavid Howells buf += bytes; 50250ec76a11SDavid Howells addr += bytes; 50260ec76a11SDavid Howells } 5027d8ed45c5SMichel Lespinasse mmap_read_unlock(mm); 50280ec76a11SDavid Howells 50290ec76a11SDavid Howells return buf - old_buf; 50300ec76a11SDavid Howells } 503103252919SAndi Kleen 50325ddd36b9SStephen Wilson /** 5033ae91dbfcSRandy Dunlap * access_remote_vm - access another process' address space 50345ddd36b9SStephen Wilson * @mm: the mm_struct of the target address space 50355ddd36b9SStephen Wilson * @addr: start address to access 50365ddd36b9SStephen Wilson * @buf: source or destination buffer 50375ddd36b9SStephen Wilson * @len: number of bytes to transfer 50386347e8d5SLorenzo Stoakes * @gup_flags: flags modifying lookup behaviour 50395ddd36b9SStephen Wilson * 50405ddd36b9SStephen Wilson * The caller must hold a reference on @mm. 5041a862f68aSMike Rapoport * 5042a862f68aSMike Rapoport * Return: number of bytes copied from source to destination. 50435ddd36b9SStephen Wilson */ 50445ddd36b9SStephen Wilson int access_remote_vm(struct mm_struct *mm, unsigned long addr, 50456347e8d5SLorenzo Stoakes void *buf, int len, unsigned int gup_flags) 50465ddd36b9SStephen Wilson { 5047d3f5ffcaSJohn Hubbard return __access_remote_vm(mm, addr, buf, len, gup_flags); 50485ddd36b9SStephen Wilson } 50495ddd36b9SStephen Wilson 505003252919SAndi Kleen /* 5051206cb636SStephen Wilson * Access another process' address space. 5052206cb636SStephen Wilson * Source/target buffer must be kernel space, 5053206cb636SStephen Wilson * Do not walk the page table directly, use get_user_pages 5054206cb636SStephen Wilson */ 5055206cb636SStephen Wilson int access_process_vm(struct task_struct *tsk, unsigned long addr, 5056f307ab6dSLorenzo Stoakes void *buf, int len, unsigned int gup_flags) 5057206cb636SStephen Wilson { 5058206cb636SStephen Wilson struct mm_struct *mm; 5059206cb636SStephen Wilson int ret; 5060206cb636SStephen Wilson 5061206cb636SStephen Wilson mm = get_task_mm(tsk); 5062206cb636SStephen Wilson if (!mm) 5063206cb636SStephen Wilson return 0; 5064206cb636SStephen Wilson 5065d3f5ffcaSJohn Hubbard ret = __access_remote_vm(mm, addr, buf, len, gup_flags); 5066442486ecSLorenzo Stoakes 5067206cb636SStephen Wilson mmput(mm); 5068206cb636SStephen Wilson 5069206cb636SStephen Wilson return ret; 5070206cb636SStephen Wilson } 5071fcd35857SCatalin Marinas EXPORT_SYMBOL_GPL(access_process_vm); 5072206cb636SStephen Wilson 507303252919SAndi Kleen /* 507403252919SAndi Kleen * Print the name of a VMA. 507503252919SAndi Kleen */ 507603252919SAndi Kleen void print_vma_addr(char *prefix, unsigned long ip) 507703252919SAndi Kleen { 507803252919SAndi Kleen struct mm_struct *mm = current->mm; 507903252919SAndi Kleen struct vm_area_struct *vma; 508003252919SAndi Kleen 5081e8bff74aSIngo Molnar /* 50820a7f682dSMichal Hocko * we might be running from an atomic context so we cannot sleep 5083e8bff74aSIngo Molnar */ 5084d8ed45c5SMichel Lespinasse if (!mmap_read_trylock(mm)) 5085e8bff74aSIngo Molnar return; 5086e8bff74aSIngo Molnar 508703252919SAndi Kleen vma = find_vma(mm, ip); 508803252919SAndi Kleen if (vma && vma->vm_file) { 508903252919SAndi Kleen struct file *f = vma->vm_file; 50900a7f682dSMichal Hocko char *buf = (char *)__get_free_page(GFP_NOWAIT); 509103252919SAndi Kleen if (buf) { 50922fbc57c5SAndy Shevchenko char *p; 509303252919SAndi Kleen 50949bf39ab2SMiklos Szeredi p = file_path(f, buf, PAGE_SIZE); 509503252919SAndi Kleen if (IS_ERR(p)) 509603252919SAndi Kleen p = "?"; 50972fbc57c5SAndy Shevchenko printk("%s%s[%lx+%lx]", prefix, kbasename(p), 509803252919SAndi Kleen vma->vm_start, 509903252919SAndi Kleen vma->vm_end - vma->vm_start); 510003252919SAndi Kleen free_page((unsigned long)buf); 510103252919SAndi Kleen } 510203252919SAndi Kleen } 5103d8ed45c5SMichel Lespinasse mmap_read_unlock(mm); 510403252919SAndi Kleen } 51053ee1afa3SNick Piggin 5106662bbcb2SMichael S. Tsirkin #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_DEBUG_ATOMIC_SLEEP) 51079ec23531SDavid Hildenbrand void __might_fault(const char *file, int line) 51083ee1afa3SNick Piggin { 510995156f00SPeter Zijlstra /* 511095156f00SPeter Zijlstra * Some code (nfs/sunrpc) uses socket ops on kernel memory while 5111c1e8d7c6SMichel Lespinasse * holding the mmap_lock, this is safe because kernel memory doesn't 511295156f00SPeter Zijlstra * get paged out, therefore we'll never actually fault, and the 511395156f00SPeter Zijlstra * below annotations will generate false positives. 511495156f00SPeter Zijlstra */ 5115db68ce10SAl Viro if (uaccess_kernel()) 511695156f00SPeter Zijlstra return; 51179ec23531SDavid Hildenbrand if (pagefault_disabled()) 5118662bbcb2SMichael S. Tsirkin return; 51199ec23531SDavid Hildenbrand __might_sleep(file, line, 0); 51209ec23531SDavid Hildenbrand #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) 5121662bbcb2SMichael S. Tsirkin if (current->mm) 5122da1c55f1SMichel Lespinasse might_lock_read(¤t->mm->mmap_lock); 51239ec23531SDavid Hildenbrand #endif 51243ee1afa3SNick Piggin } 51259ec23531SDavid Hildenbrand EXPORT_SYMBOL(__might_fault); 51263ee1afa3SNick Piggin #endif 512747ad8475SAndrea Arcangeli 512847ad8475SAndrea Arcangeli #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS) 5129c6ddfb6cSHuang Ying /* 5130c6ddfb6cSHuang Ying * Process all subpages of the specified huge page with the specified 5131c6ddfb6cSHuang Ying * operation. The target subpage will be processed last to keep its 5132c6ddfb6cSHuang Ying * cache lines hot. 5133c6ddfb6cSHuang Ying */ 5134c6ddfb6cSHuang Ying static inline void process_huge_page( 5135c6ddfb6cSHuang Ying unsigned long addr_hint, unsigned int pages_per_huge_page, 5136c6ddfb6cSHuang Ying void (*process_subpage)(unsigned long addr, int idx, void *arg), 5137c6ddfb6cSHuang Ying void *arg) 5138c6ddfb6cSHuang Ying { 5139c6ddfb6cSHuang Ying int i, n, base, l; 5140c6ddfb6cSHuang Ying unsigned long addr = addr_hint & 5141c6ddfb6cSHuang Ying ~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1); 5142c6ddfb6cSHuang Ying 5143c6ddfb6cSHuang Ying /* Process target subpage last to keep its cache lines hot */ 5144c6ddfb6cSHuang Ying might_sleep(); 5145c6ddfb6cSHuang Ying n = (addr_hint - addr) / PAGE_SIZE; 5146c6ddfb6cSHuang Ying if (2 * n <= pages_per_huge_page) { 5147c6ddfb6cSHuang Ying /* If target subpage in first half of huge page */ 5148c6ddfb6cSHuang Ying base = 0; 5149c6ddfb6cSHuang Ying l = n; 5150c6ddfb6cSHuang Ying /* Process subpages at the end of huge page */ 5151c6ddfb6cSHuang Ying for (i = pages_per_huge_page - 1; i >= 2 * n; i--) { 5152c6ddfb6cSHuang Ying cond_resched(); 5153c6ddfb6cSHuang Ying process_subpage(addr + i * PAGE_SIZE, i, arg); 5154c6ddfb6cSHuang Ying } 5155c6ddfb6cSHuang Ying } else { 5156c6ddfb6cSHuang Ying /* If target subpage in second half of huge page */ 5157c6ddfb6cSHuang Ying base = pages_per_huge_page - 2 * (pages_per_huge_page - n); 5158c6ddfb6cSHuang Ying l = pages_per_huge_page - n; 5159c6ddfb6cSHuang Ying /* Process subpages at the begin of huge page */ 5160c6ddfb6cSHuang Ying for (i = 0; i < base; i++) { 5161c6ddfb6cSHuang Ying cond_resched(); 5162c6ddfb6cSHuang Ying process_subpage(addr + i * PAGE_SIZE, i, arg); 5163c6ddfb6cSHuang Ying } 5164c6ddfb6cSHuang Ying } 5165c6ddfb6cSHuang Ying /* 5166c6ddfb6cSHuang Ying * Process remaining subpages in left-right-left-right pattern 5167c6ddfb6cSHuang Ying * towards the target subpage 5168c6ddfb6cSHuang Ying */ 5169c6ddfb6cSHuang Ying for (i = 0; i < l; i++) { 5170c6ddfb6cSHuang Ying int left_idx = base + i; 5171c6ddfb6cSHuang Ying int right_idx = base + 2 * l - 1 - i; 5172c6ddfb6cSHuang Ying 5173c6ddfb6cSHuang Ying cond_resched(); 5174c6ddfb6cSHuang Ying process_subpage(addr + left_idx * PAGE_SIZE, left_idx, arg); 5175c6ddfb6cSHuang Ying cond_resched(); 5176c6ddfb6cSHuang Ying process_subpage(addr + right_idx * PAGE_SIZE, right_idx, arg); 5177c6ddfb6cSHuang Ying } 5178c6ddfb6cSHuang Ying } 5179c6ddfb6cSHuang Ying 518047ad8475SAndrea Arcangeli static void clear_gigantic_page(struct page *page, 518147ad8475SAndrea Arcangeli unsigned long addr, 518247ad8475SAndrea Arcangeli unsigned int pages_per_huge_page) 518347ad8475SAndrea Arcangeli { 518447ad8475SAndrea Arcangeli int i; 518547ad8475SAndrea Arcangeli struct page *p = page; 518647ad8475SAndrea Arcangeli 518747ad8475SAndrea Arcangeli might_sleep(); 518847ad8475SAndrea Arcangeli for (i = 0; i < pages_per_huge_page; 518947ad8475SAndrea Arcangeli i++, p = mem_map_next(p, page, i)) { 519047ad8475SAndrea Arcangeli cond_resched(); 519147ad8475SAndrea Arcangeli clear_user_highpage(p, addr + i * PAGE_SIZE); 519247ad8475SAndrea Arcangeli } 519347ad8475SAndrea Arcangeli } 5194c6ddfb6cSHuang Ying 5195c6ddfb6cSHuang Ying static void clear_subpage(unsigned long addr, int idx, void *arg) 5196c6ddfb6cSHuang Ying { 5197c6ddfb6cSHuang Ying struct page *page = arg; 5198c6ddfb6cSHuang Ying 5199c6ddfb6cSHuang Ying clear_user_highpage(page + idx, addr); 5200c6ddfb6cSHuang Ying } 5201c6ddfb6cSHuang Ying 520247ad8475SAndrea Arcangeli void clear_huge_page(struct page *page, 5203c79b57e4SHuang Ying unsigned long addr_hint, unsigned int pages_per_huge_page) 520447ad8475SAndrea Arcangeli { 5205c79b57e4SHuang Ying unsigned long addr = addr_hint & 5206c79b57e4SHuang Ying ~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1); 520747ad8475SAndrea Arcangeli 520847ad8475SAndrea Arcangeli if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) { 520947ad8475SAndrea Arcangeli clear_gigantic_page(page, addr, pages_per_huge_page); 521047ad8475SAndrea Arcangeli return; 521147ad8475SAndrea Arcangeli } 521247ad8475SAndrea Arcangeli 5213c6ddfb6cSHuang Ying process_huge_page(addr_hint, pages_per_huge_page, clear_subpage, page); 521447ad8475SAndrea Arcangeli } 521547ad8475SAndrea Arcangeli 521647ad8475SAndrea Arcangeli static void copy_user_gigantic_page(struct page *dst, struct page *src, 521747ad8475SAndrea Arcangeli unsigned long addr, 521847ad8475SAndrea Arcangeli struct vm_area_struct *vma, 521947ad8475SAndrea Arcangeli unsigned int pages_per_huge_page) 522047ad8475SAndrea Arcangeli { 522147ad8475SAndrea Arcangeli int i; 522247ad8475SAndrea Arcangeli struct page *dst_base = dst; 522347ad8475SAndrea Arcangeli struct page *src_base = src; 522447ad8475SAndrea Arcangeli 522547ad8475SAndrea Arcangeli for (i = 0; i < pages_per_huge_page; ) { 522647ad8475SAndrea Arcangeli cond_resched(); 522747ad8475SAndrea Arcangeli copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma); 522847ad8475SAndrea Arcangeli 522947ad8475SAndrea Arcangeli i++; 523047ad8475SAndrea Arcangeli dst = mem_map_next(dst, dst_base, i); 523147ad8475SAndrea Arcangeli src = mem_map_next(src, src_base, i); 523247ad8475SAndrea Arcangeli } 523347ad8475SAndrea Arcangeli } 523447ad8475SAndrea Arcangeli 5235c9f4cd71SHuang Ying struct copy_subpage_arg { 5236c9f4cd71SHuang Ying struct page *dst; 5237c9f4cd71SHuang Ying struct page *src; 5238c9f4cd71SHuang Ying struct vm_area_struct *vma; 5239c9f4cd71SHuang Ying }; 5240c9f4cd71SHuang Ying 5241c9f4cd71SHuang Ying static void copy_subpage(unsigned long addr, int idx, void *arg) 5242c9f4cd71SHuang Ying { 5243c9f4cd71SHuang Ying struct copy_subpage_arg *copy_arg = arg; 5244c9f4cd71SHuang Ying 5245c9f4cd71SHuang Ying copy_user_highpage(copy_arg->dst + idx, copy_arg->src + idx, 5246c9f4cd71SHuang Ying addr, copy_arg->vma); 5247c9f4cd71SHuang Ying } 5248c9f4cd71SHuang Ying 524947ad8475SAndrea Arcangeli void copy_user_huge_page(struct page *dst, struct page *src, 5250c9f4cd71SHuang Ying unsigned long addr_hint, struct vm_area_struct *vma, 525147ad8475SAndrea Arcangeli unsigned int pages_per_huge_page) 525247ad8475SAndrea Arcangeli { 5253c9f4cd71SHuang Ying unsigned long addr = addr_hint & 5254c9f4cd71SHuang Ying ~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1); 5255c9f4cd71SHuang Ying struct copy_subpage_arg arg = { 5256c9f4cd71SHuang Ying .dst = dst, 5257c9f4cd71SHuang Ying .src = src, 5258c9f4cd71SHuang Ying .vma = vma, 5259c9f4cd71SHuang Ying }; 526047ad8475SAndrea Arcangeli 526147ad8475SAndrea Arcangeli if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) { 526247ad8475SAndrea Arcangeli copy_user_gigantic_page(dst, src, addr, vma, 526347ad8475SAndrea Arcangeli pages_per_huge_page); 526447ad8475SAndrea Arcangeli return; 526547ad8475SAndrea Arcangeli } 526647ad8475SAndrea Arcangeli 5267c9f4cd71SHuang Ying process_huge_page(addr_hint, pages_per_huge_page, copy_subpage, &arg); 526847ad8475SAndrea Arcangeli } 5269fa4d75c1SMike Kravetz 5270fa4d75c1SMike Kravetz long copy_huge_page_from_user(struct page *dst_page, 5271fa4d75c1SMike Kravetz const void __user *usr_src, 5272810a56b9SMike Kravetz unsigned int pages_per_huge_page, 5273810a56b9SMike Kravetz bool allow_pagefault) 5274fa4d75c1SMike Kravetz { 5275fa4d75c1SMike Kravetz void *src = (void *)usr_src; 5276fa4d75c1SMike Kravetz void *page_kaddr; 5277fa4d75c1SMike Kravetz unsigned long i, rc = 0; 5278fa4d75c1SMike Kravetz unsigned long ret_val = pages_per_huge_page * PAGE_SIZE; 52793272cfc2SMike Kravetz struct page *subpage = dst_page; 5280fa4d75c1SMike Kravetz 52813272cfc2SMike Kravetz for (i = 0; i < pages_per_huge_page; 52823272cfc2SMike Kravetz i++, subpage = mem_map_next(subpage, dst_page, i)) { 5283810a56b9SMike Kravetz if (allow_pagefault) 52843272cfc2SMike Kravetz page_kaddr = kmap(subpage); 5285810a56b9SMike Kravetz else 52863272cfc2SMike Kravetz page_kaddr = kmap_atomic(subpage); 5287fa4d75c1SMike Kravetz rc = copy_from_user(page_kaddr, 5288fa4d75c1SMike Kravetz (const void __user *)(src + i * PAGE_SIZE), 5289fa4d75c1SMike Kravetz PAGE_SIZE); 5290810a56b9SMike Kravetz if (allow_pagefault) 52913272cfc2SMike Kravetz kunmap(subpage); 5292810a56b9SMike Kravetz else 5293fa4d75c1SMike Kravetz kunmap_atomic(page_kaddr); 5294fa4d75c1SMike Kravetz 5295fa4d75c1SMike Kravetz ret_val -= (PAGE_SIZE - rc); 5296fa4d75c1SMike Kravetz if (rc) 5297fa4d75c1SMike Kravetz break; 5298fa4d75c1SMike Kravetz 5299fa4d75c1SMike Kravetz cond_resched(); 5300fa4d75c1SMike Kravetz } 5301fa4d75c1SMike Kravetz return ret_val; 5302fa4d75c1SMike Kravetz } 530347ad8475SAndrea Arcangeli #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */ 530449076ec2SKirill A. Shutemov 530540b64acdSOlof Johansson #if USE_SPLIT_PTE_PTLOCKS && ALLOC_SPLIT_PTLOCKS 5306b35f1819SKirill A. Shutemov 5307b35f1819SKirill A. Shutemov static struct kmem_cache *page_ptl_cachep; 5308b35f1819SKirill A. Shutemov 5309b35f1819SKirill A. Shutemov void __init ptlock_cache_init(void) 5310b35f1819SKirill A. Shutemov { 5311b35f1819SKirill A. Shutemov page_ptl_cachep = kmem_cache_create("page->ptl", sizeof(spinlock_t), 0, 5312b35f1819SKirill A. Shutemov SLAB_PANIC, NULL); 5313b35f1819SKirill A. Shutemov } 5314b35f1819SKirill A. Shutemov 5315539edb58SPeter Zijlstra bool ptlock_alloc(struct page *page) 531649076ec2SKirill A. Shutemov { 531749076ec2SKirill A. Shutemov spinlock_t *ptl; 531849076ec2SKirill A. Shutemov 5319b35f1819SKirill A. Shutemov ptl = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL); 532049076ec2SKirill A. Shutemov if (!ptl) 532149076ec2SKirill A. Shutemov return false; 5322539edb58SPeter Zijlstra page->ptl = ptl; 532349076ec2SKirill A. Shutemov return true; 532449076ec2SKirill A. Shutemov } 532549076ec2SKirill A. Shutemov 5326539edb58SPeter Zijlstra void ptlock_free(struct page *page) 532749076ec2SKirill A. Shutemov { 5328b35f1819SKirill A. Shutemov kmem_cache_free(page_ptl_cachep, page->ptl); 532949076ec2SKirill A. Shutemov } 533049076ec2SKirill A. Shutemov #endif 5331