1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/mm/nommu.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Replacement code for mm functions to support CPU's that don't 61da177e4SLinus Torvalds * have any form of memory management unit (thus no virtual memory). 71da177e4SLinus Torvalds * 8dd19d293SStephen Kitt * See Documentation/admin-guide/mm/nommu-mmap.rst 91da177e4SLinus Torvalds * 108feae131SDavid Howells * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com> 111da177e4SLinus Torvalds * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> 121da177e4SLinus Torvalds * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> 131da177e4SLinus Torvalds * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> 1429c185e5SPaul Mundt * Copyright (c) 2007-2010 Paul Mundt <lethal@linux-sh.org> 151da177e4SLinus Torvalds */ 161da177e4SLinus Torvalds 17b1de0d13SMitchel Humpherys #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18b1de0d13SMitchel Humpherys 19b95f1b31SPaul Gortmaker #include <linux/export.h> 201da177e4SLinus Torvalds #include <linux/mm.h> 216e84f315SIngo Molnar #include <linux/sched/mm.h> 22615d6e87SDavidlohr Bueso #include <linux/vmacache.h> 231da177e4SLinus Torvalds #include <linux/mman.h> 241da177e4SLinus Torvalds #include <linux/swap.h> 251da177e4SLinus Torvalds #include <linux/file.h> 261da177e4SLinus Torvalds #include <linux/highmem.h> 271da177e4SLinus Torvalds #include <linux/pagemap.h> 281da177e4SLinus Torvalds #include <linux/slab.h> 291da177e4SLinus Torvalds #include <linux/vmalloc.h> 301da177e4SLinus Torvalds #include <linux/backing-dev.h> 313b32123dSGideon Israel Dsouza #include <linux/compiler.h> 321da177e4SLinus Torvalds #include <linux/mount.h> 331da177e4SLinus Torvalds #include <linux/personality.h> 341da177e4SLinus Torvalds #include <linux/security.h> 351da177e4SLinus Torvalds #include <linux/syscalls.h> 36120a795dSAl Viro #include <linux/audit.h> 37b1de0d13SMitchel Humpherys #include <linux/printk.h> 381da177e4SLinus Torvalds 397c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 401da177e4SLinus Torvalds #include <asm/tlb.h> 411da177e4SLinus Torvalds #include <asm/tlbflush.h> 42eb8cdec4SBernd Schmidt #include <asm/mmu_context.h> 438feae131SDavid Howells #include "internal.h" 448feae131SDavid Howells 451da177e4SLinus Torvalds void *high_memory; 46944b6874SArnd Bergmann EXPORT_SYMBOL(high_memory); 471da177e4SLinus Torvalds struct page *mem_map; 481da177e4SLinus Torvalds unsigned long max_mapnr; 495b8bf307Sgchen gchen EXPORT_SYMBOL(max_mapnr); 504266c97aSHugh Dickins unsigned long highest_memmap_pfn; 51fc4d5c29SDavid Howells int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; 521da177e4SLinus Torvalds int heap_stack_gap = 0; 531da177e4SLinus Torvalds 5433e5d769SDavid Howells atomic_long_t mmap_pages_allocated; 558feae131SDavid Howells 561da177e4SLinus Torvalds EXPORT_SYMBOL(mem_map); 571da177e4SLinus Torvalds 588feae131SDavid Howells /* list of mapped, potentially shareable regions */ 598feae131SDavid Howells static struct kmem_cache *vm_region_jar; 608feae131SDavid Howells struct rb_root nommu_region_tree = RB_ROOT; 618feae131SDavid Howells DECLARE_RWSEM(nommu_region_sem); 621da177e4SLinus Torvalds 63f0f37e2fSAlexey Dobriyan const struct vm_operations_struct generic_file_vm_ops = { 641da177e4SLinus Torvalds }; 651da177e4SLinus Torvalds 661da177e4SLinus Torvalds /* 671da177e4SLinus Torvalds * Return the total memory allocated for this pointer, not 681da177e4SLinus Torvalds * just what the caller asked for. 691da177e4SLinus Torvalds * 701da177e4SLinus Torvalds * Doesn't have to be accurate, i.e. may have races. 711da177e4SLinus Torvalds */ 721da177e4SLinus Torvalds unsigned int kobjsize(const void *objp) 731da177e4SLinus Torvalds { 741da177e4SLinus Torvalds struct page *page; 751da177e4SLinus Torvalds 764016a139SMichael Hennerich /* 774016a139SMichael Hennerich * If the object we have should not have ksize performed on it, 784016a139SMichael Hennerich * return size of 0 794016a139SMichael Hennerich */ 805a1603beSPaul Mundt if (!objp || !virt_addr_valid(objp)) 816cfd53fcSPaul Mundt return 0; 826cfd53fcSPaul Mundt 836cfd53fcSPaul Mundt page = virt_to_head_page(objp); 846cfd53fcSPaul Mundt 856cfd53fcSPaul Mundt /* 866cfd53fcSPaul Mundt * If the allocator sets PageSlab, we know the pointer came from 876cfd53fcSPaul Mundt * kmalloc(). 886cfd53fcSPaul Mundt */ 891da177e4SLinus Torvalds if (PageSlab(page)) 901da177e4SLinus Torvalds return ksize(objp); 911da177e4SLinus Torvalds 926cfd53fcSPaul Mundt /* 93ab2e83eaSPaul Mundt * If it's not a compound page, see if we have a matching VMA 94ab2e83eaSPaul Mundt * region. This test is intentionally done in reverse order, 95ab2e83eaSPaul Mundt * so if there's no VMA, we still fall through and hand back 96ab2e83eaSPaul Mundt * PAGE_SIZE for 0-order pages. 97ab2e83eaSPaul Mundt */ 98ab2e83eaSPaul Mundt if (!PageCompound(page)) { 99ab2e83eaSPaul Mundt struct vm_area_struct *vma; 100ab2e83eaSPaul Mundt 101ab2e83eaSPaul Mundt vma = find_vma(current->mm, (unsigned long)objp); 102ab2e83eaSPaul Mundt if (vma) 103ab2e83eaSPaul Mundt return vma->vm_end - vma->vm_start; 104ab2e83eaSPaul Mundt } 105ab2e83eaSPaul Mundt 106ab2e83eaSPaul Mundt /* 1076cfd53fcSPaul Mundt * The ksize() function is only guaranteed to work for pointers 1085a1603beSPaul Mundt * returned by kmalloc(). So handle arbitrary pointers here. 1096cfd53fcSPaul Mundt */ 110a50b854eSMatthew Wilcox (Oracle) return page_size(page); 1111da177e4SLinus Torvalds } 1121da177e4SLinus Torvalds 113dfc2f91aSPaul Mundt /** 114dfc2f91aSPaul Mundt * follow_pfn - look up PFN at a user virtual address 115dfc2f91aSPaul Mundt * @vma: memory mapping 116dfc2f91aSPaul Mundt * @address: user virtual address 117dfc2f91aSPaul Mundt * @pfn: location to store found PFN 118dfc2f91aSPaul Mundt * 119dfc2f91aSPaul Mundt * Only IO mappings and raw PFN mappings are allowed. 120dfc2f91aSPaul Mundt * 121dfc2f91aSPaul Mundt * Returns zero and the pfn at @pfn on success, -ve otherwise. 122dfc2f91aSPaul Mundt */ 123dfc2f91aSPaul Mundt int follow_pfn(struct vm_area_struct *vma, unsigned long address, 124dfc2f91aSPaul Mundt unsigned long *pfn) 125dfc2f91aSPaul Mundt { 126dfc2f91aSPaul Mundt if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 127dfc2f91aSPaul Mundt return -EINVAL; 128dfc2f91aSPaul Mundt 129dfc2f91aSPaul Mundt *pfn = address >> PAGE_SHIFT; 130dfc2f91aSPaul Mundt return 0; 131dfc2f91aSPaul Mundt } 132dfc2f91aSPaul Mundt EXPORT_SYMBOL(follow_pfn); 133dfc2f91aSPaul Mundt 134f1c4069eSJoonsoo Kim LIST_HEAD(vmap_area_list); 1351da177e4SLinus Torvalds 136b3bdda02SChristoph Lameter void vfree(const void *addr) 1371da177e4SLinus Torvalds { 1381da177e4SLinus Torvalds kfree(addr); 1391da177e4SLinus Torvalds } 140b5073173SPaul Mundt EXPORT_SYMBOL(vfree); 1411da177e4SLinus Torvalds 14288dca4caSChristoph Hellwig void *__vmalloc(unsigned long size, gfp_t gfp_mask) 1431da177e4SLinus Torvalds { 1441da177e4SLinus Torvalds /* 1458518609dSRobert P. J. Day * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() 1468518609dSRobert P. J. Day * returns only a logical address. 1471da177e4SLinus Torvalds */ 14884097518SNick Piggin return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); 1491da177e4SLinus Torvalds } 150b5073173SPaul Mundt EXPORT_SYMBOL(__vmalloc); 1511da177e4SLinus Torvalds 152041de93fSChristoph Hellwig void *__vmalloc_node_range(unsigned long size, unsigned long align, 153041de93fSChristoph Hellwig unsigned long start, unsigned long end, gfp_t gfp_mask, 154041de93fSChristoph Hellwig pgprot_t prot, unsigned long vm_flags, int node, 155041de93fSChristoph Hellwig const void *caller) 156041de93fSChristoph Hellwig { 157041de93fSChristoph Hellwig return __vmalloc(size, gfp_mask); 158041de93fSChristoph Hellwig } 159041de93fSChristoph Hellwig 1602b905948SChristoph Hellwig void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, 1612b905948SChristoph Hellwig int node, const void *caller) 162a7c3e901SMichal Hocko { 1632b905948SChristoph Hellwig return __vmalloc(size, gfp_mask); 164a7c3e901SMichal Hocko } 165a7c3e901SMichal Hocko 166ed81745aSAndrii Nakryiko static void *__vmalloc_user_flags(unsigned long size, gfp_t flags) 167f905bc44SPaul Mundt { 168f905bc44SPaul Mundt void *ret; 169f905bc44SPaul Mundt 17088dca4caSChristoph Hellwig ret = __vmalloc(size, flags); 171f905bc44SPaul Mundt if (ret) { 172f905bc44SPaul Mundt struct vm_area_struct *vma; 173f905bc44SPaul Mundt 174d8ed45c5SMichel Lespinasse mmap_write_lock(current->mm); 175f905bc44SPaul Mundt vma = find_vma(current->mm, (unsigned long)ret); 176f905bc44SPaul Mundt if (vma) 177f905bc44SPaul Mundt vma->vm_flags |= VM_USERMAP; 178d8ed45c5SMichel Lespinasse mmap_write_unlock(current->mm); 179f905bc44SPaul Mundt } 180f905bc44SPaul Mundt 181f905bc44SPaul Mundt return ret; 182f905bc44SPaul Mundt } 183ed81745aSAndrii Nakryiko 184ed81745aSAndrii Nakryiko void *vmalloc_user(unsigned long size) 185ed81745aSAndrii Nakryiko { 186ed81745aSAndrii Nakryiko return __vmalloc_user_flags(size, GFP_KERNEL | __GFP_ZERO); 187ed81745aSAndrii Nakryiko } 188f905bc44SPaul Mundt EXPORT_SYMBOL(vmalloc_user); 189f905bc44SPaul Mundt 190b3bdda02SChristoph Lameter struct page *vmalloc_to_page(const void *addr) 1911da177e4SLinus Torvalds { 1921da177e4SLinus Torvalds return virt_to_page(addr); 1931da177e4SLinus Torvalds } 194b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_page); 1951da177e4SLinus Torvalds 196b3bdda02SChristoph Lameter unsigned long vmalloc_to_pfn(const void *addr) 1971da177e4SLinus Torvalds { 1981da177e4SLinus Torvalds return page_to_pfn(virt_to_page(addr)); 1991da177e4SLinus Torvalds } 200b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_pfn); 2011da177e4SLinus Torvalds 2021da177e4SLinus Torvalds long vread(char *buf, char *addr, unsigned long count) 2031da177e4SLinus Torvalds { 2049bde916bSChen Gang /* Don't allow overflow */ 2059bde916bSChen Gang if ((unsigned long) buf + count < count) 2069bde916bSChen Gang count = -(unsigned long) buf; 2079bde916bSChen Gang 2081da177e4SLinus Torvalds memcpy(buf, addr, count); 2091da177e4SLinus Torvalds return count; 2101da177e4SLinus Torvalds } 2111da177e4SLinus Torvalds 2121da177e4SLinus Torvalds /* 213e1c05067SMasahiro Yamada * vmalloc - allocate virtually contiguous memory 2141da177e4SLinus Torvalds * 2151da177e4SLinus Torvalds * @size: allocation size 2161da177e4SLinus Torvalds * 2171da177e4SLinus Torvalds * Allocate enough pages to cover @size from the page level 218e1c05067SMasahiro Yamada * allocator and map them into contiguous kernel virtual space. 2191da177e4SLinus Torvalds * 220c1c8897fSMichael Opdenacker * For tight control over page level allocator and protection flags 2211da177e4SLinus Torvalds * use __vmalloc() instead. 2221da177e4SLinus Torvalds */ 2231da177e4SLinus Torvalds void *vmalloc(unsigned long size) 2241da177e4SLinus Torvalds { 225176056fdSChen Li return __vmalloc(size, GFP_KERNEL); 2261da177e4SLinus Torvalds } 227f6138882SAndrew Morton EXPORT_SYMBOL(vmalloc); 228f6138882SAndrew Morton 2290fc74d82SLinus Torvalds void *vmalloc_huge(unsigned long size, gfp_t gfp_mask) __weak __alias(__vmalloc); 2300fc74d82SLinus Torvalds 231e1ca7788SDave Young /* 232e1c05067SMasahiro Yamada * vzalloc - allocate virtually contiguous memory with zero fill 233e1ca7788SDave Young * 234e1ca7788SDave Young * @size: allocation size 235e1ca7788SDave Young * 236e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 237e1c05067SMasahiro Yamada * allocator and map them into contiguous kernel virtual space. 238e1ca7788SDave Young * The memory allocated is set to zero. 239e1ca7788SDave Young * 240e1ca7788SDave Young * For tight control over page level allocator and protection flags 241e1ca7788SDave Young * use __vmalloc() instead. 242e1ca7788SDave Young */ 243e1ca7788SDave Young void *vzalloc(unsigned long size) 244e1ca7788SDave Young { 245176056fdSChen Li return __vmalloc(size, GFP_KERNEL | __GFP_ZERO); 246e1ca7788SDave Young } 247e1ca7788SDave Young EXPORT_SYMBOL(vzalloc); 248e1ca7788SDave Young 249e1ca7788SDave Young /** 250e1ca7788SDave Young * vmalloc_node - allocate memory on a specific node 251e1ca7788SDave Young * @size: allocation size 252e1ca7788SDave Young * @node: numa node 253e1ca7788SDave Young * 254e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 255e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 256e1ca7788SDave Young * 257e1ca7788SDave Young * For tight control over page level allocator and protection flags 258e1ca7788SDave Young * use __vmalloc() instead. 259e1ca7788SDave Young */ 260f6138882SAndrew Morton void *vmalloc_node(unsigned long size, int node) 261f6138882SAndrew Morton { 262f6138882SAndrew Morton return vmalloc(size); 263f6138882SAndrew Morton } 2649a14f653SPaul Mundt EXPORT_SYMBOL(vmalloc_node); 265e1ca7788SDave Young 266e1ca7788SDave Young /** 267e1ca7788SDave Young * vzalloc_node - allocate memory on a specific node with zero fill 268e1ca7788SDave Young * @size: allocation size 269e1ca7788SDave Young * @node: numa node 270e1ca7788SDave Young * 271e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 272e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 273e1ca7788SDave Young * The memory allocated is set to zero. 274e1ca7788SDave Young * 275e1ca7788SDave Young * For tight control over page level allocator and protection flags 276e1ca7788SDave Young * use __vmalloc() instead. 277e1ca7788SDave Young */ 278e1ca7788SDave Young void *vzalloc_node(unsigned long size, int node) 279e1ca7788SDave Young { 280e1ca7788SDave Young return vzalloc(size); 281e1ca7788SDave Young } 282e1ca7788SDave Young EXPORT_SYMBOL(vzalloc_node); 2831da177e4SLinus Torvalds 2841af446edSPaul Mundt /** 285b5073173SPaul Mundt * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 2861da177e4SLinus Torvalds * @size: allocation size 2871da177e4SLinus Torvalds * 2881da177e4SLinus Torvalds * Allocate enough 32bit PA addressable pages to cover @size from the 289e1c05067SMasahiro Yamada * page level allocator and map them into contiguous kernel virtual space. 2901da177e4SLinus Torvalds */ 2911da177e4SLinus Torvalds void *vmalloc_32(unsigned long size) 2921da177e4SLinus Torvalds { 29388dca4caSChristoph Hellwig return __vmalloc(size, GFP_KERNEL); 2941da177e4SLinus Torvalds } 295b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32); 296b5073173SPaul Mundt 297b5073173SPaul Mundt /** 298b5073173SPaul Mundt * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 299b5073173SPaul Mundt * @size: allocation size 300b5073173SPaul Mundt * 301b5073173SPaul Mundt * The resulting memory area is 32bit addressable and zeroed so it can be 302b5073173SPaul Mundt * mapped to userspace without leaking data. 303f905bc44SPaul Mundt * 304f905bc44SPaul Mundt * VM_USERMAP is set on the corresponding VMA so that subsequent calls to 305f905bc44SPaul Mundt * remap_vmalloc_range() are permissible. 306b5073173SPaul Mundt */ 307b5073173SPaul Mundt void *vmalloc_32_user(unsigned long size) 308b5073173SPaul Mundt { 309f905bc44SPaul Mundt /* 310f905bc44SPaul Mundt * We'll have to sort out the ZONE_DMA bits for 64-bit, 311f905bc44SPaul Mundt * but for now this can simply use vmalloc_user() directly. 312f905bc44SPaul Mundt */ 313f905bc44SPaul Mundt return vmalloc_user(size); 314b5073173SPaul Mundt } 315b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32_user); 3161da177e4SLinus Torvalds 3171da177e4SLinus Torvalds void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) 3181da177e4SLinus Torvalds { 3191da177e4SLinus Torvalds BUG(); 3201da177e4SLinus Torvalds return NULL; 3211da177e4SLinus Torvalds } 322b5073173SPaul Mundt EXPORT_SYMBOL(vmap); 3231da177e4SLinus Torvalds 324b3bdda02SChristoph Lameter void vunmap(const void *addr) 3251da177e4SLinus Torvalds { 3261da177e4SLinus Torvalds BUG(); 3271da177e4SLinus Torvalds } 328b5073173SPaul Mundt EXPORT_SYMBOL(vunmap); 3291da177e4SLinus Torvalds 330d4efd79aSChristoph Hellwig void *vm_map_ram(struct page **pages, unsigned int count, int node) 331eb6434d9SPaul Mundt { 332eb6434d9SPaul Mundt BUG(); 333eb6434d9SPaul Mundt return NULL; 334eb6434d9SPaul Mundt } 335eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_map_ram); 336eb6434d9SPaul Mundt 337eb6434d9SPaul Mundt void vm_unmap_ram(const void *mem, unsigned int count) 338eb6434d9SPaul Mundt { 339eb6434d9SPaul Mundt BUG(); 340eb6434d9SPaul Mundt } 341eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_unmap_ram); 342eb6434d9SPaul Mundt 343eb6434d9SPaul Mundt void vm_unmap_aliases(void) 344eb6434d9SPaul Mundt { 345eb6434d9SPaul Mundt } 346eb6434d9SPaul Mundt EXPORT_SYMBOL_GPL(vm_unmap_aliases); 347eb6434d9SPaul Mundt 34829c185e5SPaul Mundt void free_vm_area(struct vm_struct *area) 34929c185e5SPaul Mundt { 35029c185e5SPaul Mundt BUG(); 35129c185e5SPaul Mundt } 35229c185e5SPaul Mundt EXPORT_SYMBOL_GPL(free_vm_area); 35329c185e5SPaul Mundt 354b5073173SPaul Mundt int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 355b5073173SPaul Mundt struct page *page) 356b5073173SPaul Mundt { 357b5073173SPaul Mundt return -EINVAL; 358b5073173SPaul Mundt } 359b5073173SPaul Mundt EXPORT_SYMBOL(vm_insert_page); 360b5073173SPaul Mundt 361a667d745SSouptick Joarder int vm_map_pages(struct vm_area_struct *vma, struct page **pages, 362a667d745SSouptick Joarder unsigned long num) 363a667d745SSouptick Joarder { 364a667d745SSouptick Joarder return -EINVAL; 365a667d745SSouptick Joarder } 366a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages); 367a667d745SSouptick Joarder 368a667d745SSouptick Joarder int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, 369a667d745SSouptick Joarder unsigned long num) 370a667d745SSouptick Joarder { 371a667d745SSouptick Joarder return -EINVAL; 372a667d745SSouptick Joarder } 373a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages_zero); 374a667d745SSouptick Joarder 3751eeb66a1SChristoph Hellwig /* 3761da177e4SLinus Torvalds * sys_brk() for the most part doesn't need the global kernel 3771da177e4SLinus Torvalds * lock, except when an application is doing something nasty 3781da177e4SLinus Torvalds * like trying to un-brk an area that has already been mapped 3791da177e4SLinus Torvalds * to a regular file. in this case, the unmapping will need 3801da177e4SLinus Torvalds * to invoke file system routines that need the global lock. 3811da177e4SLinus Torvalds */ 3826a6160a7SHeiko Carstens SYSCALL_DEFINE1(brk, unsigned long, brk) 3831da177e4SLinus Torvalds { 3841da177e4SLinus Torvalds struct mm_struct *mm = current->mm; 3851da177e4SLinus Torvalds 3861da177e4SLinus Torvalds if (brk < mm->start_brk || brk > mm->context.end_brk) 3871da177e4SLinus Torvalds return mm->brk; 3881da177e4SLinus Torvalds 3891da177e4SLinus Torvalds if (mm->brk == brk) 3901da177e4SLinus Torvalds return mm->brk; 3911da177e4SLinus Torvalds 3921da177e4SLinus Torvalds /* 3931da177e4SLinus Torvalds * Always allow shrinking brk 3941da177e4SLinus Torvalds */ 3951da177e4SLinus Torvalds if (brk <= mm->brk) { 3961da177e4SLinus Torvalds mm->brk = brk; 3971da177e4SLinus Torvalds return brk; 3981da177e4SLinus Torvalds } 3991da177e4SLinus Torvalds 4001da177e4SLinus Torvalds /* 4011da177e4SLinus Torvalds * Ok, looks good - let it rip. 4021da177e4SLinus Torvalds */ 403a75a2df6SChristoph Hellwig flush_icache_user_range(mm->brk, brk); 4041da177e4SLinus Torvalds return mm->brk = brk; 4051da177e4SLinus Torvalds } 4061da177e4SLinus Torvalds 4078feae131SDavid Howells /* 4083edf41d8Sseokhoon.yoon * initialise the percpu counter for VM and region record slabs 4098feae131SDavid Howells */ 4108feae131SDavid Howells void __init mmap_init(void) 4111da177e4SLinus Torvalds { 41200a62ce9SKOSAKI Motohiro int ret; 41300a62ce9SKOSAKI Motohiro 414908c7f19STejun Heo ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); 41500a62ce9SKOSAKI Motohiro VM_BUG_ON(ret); 4165d097056SVladimir Davydov vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC|SLAB_ACCOUNT); 4178feae131SDavid Howells } 4181da177e4SLinus Torvalds 4198feae131SDavid Howells /* 4208feae131SDavid Howells * validate the region tree 4218feae131SDavid Howells * - the caller must hold the region lock 4228feae131SDavid Howells */ 4238feae131SDavid Howells #ifdef CONFIG_DEBUG_NOMMU_REGIONS 4248feae131SDavid Howells static noinline void validate_nommu_regions(void) 4258feae131SDavid Howells { 4268feae131SDavid Howells struct vm_region *region, *last; 4278feae131SDavid Howells struct rb_node *p, *lastp; 4281da177e4SLinus Torvalds 4298feae131SDavid Howells lastp = rb_first(&nommu_region_tree); 4308feae131SDavid Howells if (!lastp) 4318feae131SDavid Howells return; 4328feae131SDavid Howells 4338feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 434c9427bc0SGeliang Tang BUG_ON(last->vm_end <= last->vm_start); 435c9427bc0SGeliang Tang BUG_ON(last->vm_top < last->vm_end); 4368feae131SDavid Howells 4378feae131SDavid Howells while ((p = rb_next(lastp))) { 4388feae131SDavid Howells region = rb_entry(p, struct vm_region, vm_rb); 4398feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 4408feae131SDavid Howells 441c9427bc0SGeliang Tang BUG_ON(region->vm_end <= region->vm_start); 442c9427bc0SGeliang Tang BUG_ON(region->vm_top < region->vm_end); 443c9427bc0SGeliang Tang BUG_ON(region->vm_start < last->vm_top); 4448feae131SDavid Howells 4458feae131SDavid Howells lastp = p; 4461da177e4SLinus Torvalds } 4471da177e4SLinus Torvalds } 4488feae131SDavid Howells #else 44933e5d769SDavid Howells static void validate_nommu_regions(void) 45033e5d769SDavid Howells { 45133e5d769SDavid Howells } 4528feae131SDavid Howells #endif 4538feae131SDavid Howells 4548feae131SDavid Howells /* 4558feae131SDavid Howells * add a region into the global tree 4568feae131SDavid Howells */ 4578feae131SDavid Howells static void add_nommu_region(struct vm_region *region) 4588feae131SDavid Howells { 4598feae131SDavid Howells struct vm_region *pregion; 4608feae131SDavid Howells struct rb_node **p, *parent; 4618feae131SDavid Howells 4628feae131SDavid Howells validate_nommu_regions(); 4638feae131SDavid Howells 4648feae131SDavid Howells parent = NULL; 4658feae131SDavid Howells p = &nommu_region_tree.rb_node; 4668feae131SDavid Howells while (*p) { 4678feae131SDavid Howells parent = *p; 4688feae131SDavid Howells pregion = rb_entry(parent, struct vm_region, vm_rb); 4698feae131SDavid Howells if (region->vm_start < pregion->vm_start) 4708feae131SDavid Howells p = &(*p)->rb_left; 4718feae131SDavid Howells else if (region->vm_start > pregion->vm_start) 4728feae131SDavid Howells p = &(*p)->rb_right; 4738feae131SDavid Howells else if (pregion == region) 4748feae131SDavid Howells return; 4758feae131SDavid Howells else 4768feae131SDavid Howells BUG(); 4778feae131SDavid Howells } 4788feae131SDavid Howells 4798feae131SDavid Howells rb_link_node(®ion->vm_rb, parent, p); 4808feae131SDavid Howells rb_insert_color(®ion->vm_rb, &nommu_region_tree); 4818feae131SDavid Howells 4828feae131SDavid Howells validate_nommu_regions(); 4838feae131SDavid Howells } 4848feae131SDavid Howells 4858feae131SDavid Howells /* 4868feae131SDavid Howells * delete a region from the global tree 4878feae131SDavid Howells */ 4888feae131SDavid Howells static void delete_nommu_region(struct vm_region *region) 4898feae131SDavid Howells { 4908feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 4918feae131SDavid Howells 4928feae131SDavid Howells validate_nommu_regions(); 4938feae131SDavid Howells rb_erase(®ion->vm_rb, &nommu_region_tree); 4948feae131SDavid Howells validate_nommu_regions(); 4958feae131SDavid Howells } 4968feae131SDavid Howells 4978feae131SDavid Howells /* 4988feae131SDavid Howells * free a contiguous series of pages 4998feae131SDavid Howells */ 5008feae131SDavid Howells static void free_page_series(unsigned long from, unsigned long to) 5018feae131SDavid Howells { 5028feae131SDavid Howells for (; from < to; from += PAGE_SIZE) { 5039330723cSLinus Walleij struct page *page = virt_to_page((void *)from); 5048feae131SDavid Howells 50533e5d769SDavid Howells atomic_long_dec(&mmap_pages_allocated); 5068feae131SDavid Howells put_page(page); 5078feae131SDavid Howells } 5088feae131SDavid Howells } 5098feae131SDavid Howells 5108feae131SDavid Howells /* 5118feae131SDavid Howells * release a reference to a region 51233e5d769SDavid Howells * - the caller must hold the region semaphore for writing, which this releases 513dd8632a1SPaul Mundt * - the region may not have been added to the tree yet, in which case vm_top 5148feae131SDavid Howells * will equal vm_start 5158feae131SDavid Howells */ 5168feae131SDavid Howells static void __put_nommu_region(struct vm_region *region) 5178feae131SDavid Howells __releases(nommu_region_sem) 5188feae131SDavid Howells { 5198feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5208feae131SDavid Howells 5211e2ae599SDavid Howells if (--region->vm_usage == 0) { 522dd8632a1SPaul Mundt if (region->vm_top > region->vm_start) 5238feae131SDavid Howells delete_nommu_region(region); 5248feae131SDavid Howells up_write(&nommu_region_sem); 5258feae131SDavid Howells 5268feae131SDavid Howells if (region->vm_file) 5278feae131SDavid Howells fput(region->vm_file); 5288feae131SDavid Howells 5298feae131SDavid Howells /* IO memory and memory shared directly out of the pagecache 5308feae131SDavid Howells * from ramfs/tmpfs mustn't be released here */ 53122cc877bSLeon Romanovsky if (region->vm_flags & VM_MAPPED_COPY) 532dd8632a1SPaul Mundt free_page_series(region->vm_start, region->vm_top); 5338feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 5348feae131SDavid Howells } else { 5358feae131SDavid Howells up_write(&nommu_region_sem); 5368feae131SDavid Howells } 5378feae131SDavid Howells } 5388feae131SDavid Howells 5398feae131SDavid Howells /* 5408feae131SDavid Howells * release a reference to a region 5418feae131SDavid Howells */ 5428feae131SDavid Howells static void put_nommu_region(struct vm_region *region) 5438feae131SDavid Howells { 5448feae131SDavid Howells down_write(&nommu_region_sem); 5458feae131SDavid Howells __put_nommu_region(region); 5468feae131SDavid Howells } 5471da177e4SLinus Torvalds 548d4af56c5SLiam R. Howlett void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas) 549d4af56c5SLiam R. Howlett { 550d4af56c5SLiam R. Howlett mas_set_range(mas, vma->vm_start, vma->vm_end - 1); 551d4af56c5SLiam R. Howlett mas_store_prealloc(mas, vma); 552d4af56c5SLiam R. Howlett } 553d4af56c5SLiam R. Howlett 554d4af56c5SLiam R. Howlett void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas) 555d4af56c5SLiam R. Howlett { 556d4af56c5SLiam R. Howlett mas->index = vma->vm_start; 557d4af56c5SLiam R. Howlett mas->last = vma->vm_end - 1; 558d4af56c5SLiam R. Howlett mas_store_prealloc(mas, NULL); 559d4af56c5SLiam R. Howlett } 560d4af56c5SLiam R. Howlett 5613034097aSDavid Howells /* 5623034097aSDavid Howells * add a VMA into a process's mm_struct in the appropriate place in the list 5638feae131SDavid Howells * and tree and add to the address space's page tree also if not an anonymous 5648feae131SDavid Howells * page 565c1e8d7c6SMichel Lespinasse * - should be called with mm->mmap_lock held writelocked 5663034097aSDavid Howells */ 5678feae131SDavid Howells static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) 5683034097aSDavid Howells { 5698feae131SDavid Howells struct address_space *mapping; 570*524e00b3SLiam R. Howlett struct vm_area_struct *prev; 571*524e00b3SLiam R. Howlett MA_STATE(mas, &mm->mm_mt, vma->vm_start, vma->vm_end); 5723034097aSDavid Howells 5738feae131SDavid Howells BUG_ON(!vma->vm_region); 5748feae131SDavid Howells 5758feae131SDavid Howells mm->map_count++; 5768feae131SDavid Howells vma->vm_mm = mm; 5778feae131SDavid Howells 5788feae131SDavid Howells /* add the VMA to the mapping */ 5798feae131SDavid Howells if (vma->vm_file) { 5808feae131SDavid Howells mapping = vma->vm_file->f_mapping; 5818feae131SDavid Howells 58283cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 5838feae131SDavid Howells flush_dcache_mmap_lock(mapping); 5846b2dbba8SMichel Lespinasse vma_interval_tree_insert(vma, &mapping->i_mmap); 5858feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 58683cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 5878feae131SDavid Howells } 5888feae131SDavid Howells 589*524e00b3SLiam R. Howlett prev = mas_prev(&mas, 0); 590*524e00b3SLiam R. Howlett mas_reset(&mas); 5918feae131SDavid Howells /* add the VMA to the tree */ 592*524e00b3SLiam R. Howlett vma_mas_store(vma, &mas); 593aba6dfb7SWei Yang __vma_link_list(mm, vma, prev); 5948feae131SDavid Howells } 5958feae131SDavid Howells 5968feae131SDavid Howells /* 5978feae131SDavid Howells * delete a VMA from its owning mm_struct and address space 5988feae131SDavid Howells */ 5998feae131SDavid Howells static void delete_vma_from_mm(struct vm_area_struct *vma) 6008feae131SDavid Howells { 601615d6e87SDavidlohr Bueso int i; 6028feae131SDavid Howells struct address_space *mapping; 6038feae131SDavid Howells struct mm_struct *mm = vma->vm_mm; 604615d6e87SDavidlohr Bueso struct task_struct *curr = current; 605*524e00b3SLiam R. Howlett MA_STATE(mas, &vma->vm_mm->mm_mt, 0, 0); 6068feae131SDavid Howells 6078feae131SDavid Howells mm->map_count--; 608615d6e87SDavidlohr Bueso for (i = 0; i < VMACACHE_SIZE; i++) { 609615d6e87SDavidlohr Bueso /* if the vma is cached, invalidate the entire cache */ 610314ff785SIngo Molnar if (curr->vmacache.vmas[i] == vma) { 611e020d5bdSSteven Miao vmacache_invalidate(mm); 612615d6e87SDavidlohr Bueso break; 613615d6e87SDavidlohr Bueso } 614615d6e87SDavidlohr Bueso } 6158feae131SDavid Howells 6168feae131SDavid Howells /* remove the VMA from the mapping */ 6178feae131SDavid Howells if (vma->vm_file) { 6188feae131SDavid Howells mapping = vma->vm_file->f_mapping; 6198feae131SDavid Howells 62083cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 6218feae131SDavid Howells flush_dcache_mmap_lock(mapping); 6226b2dbba8SMichel Lespinasse vma_interval_tree_remove(vma, &mapping->i_mmap); 6238feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 62483cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 6258feae131SDavid Howells } 6268feae131SDavid Howells 6278feae131SDavid Howells /* remove from the MM's tree and list */ 628*524e00b3SLiam R. Howlett vma_mas_remove(vma, &mas); 6291b9fc5b2SWei Yang __vma_unlink_list(mm, vma); 6308feae131SDavid Howells } 6318feae131SDavid Howells 6328feae131SDavid Howells /* 6338feae131SDavid Howells * destroy a VMA record 6348feae131SDavid Howells */ 6358feae131SDavid Howells static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) 6368feae131SDavid Howells { 6378feae131SDavid Howells if (vma->vm_ops && vma->vm_ops->close) 6388feae131SDavid Howells vma->vm_ops->close(vma); 639e9714acfSKonstantin Khlebnikov if (vma->vm_file) 6408feae131SDavid Howells fput(vma->vm_file); 6418feae131SDavid Howells put_nommu_region(vma->vm_region); 6423928d4f5SLinus Torvalds vm_area_free(vma); 6433034097aSDavid Howells } 6443034097aSDavid Howells 6453034097aSDavid Howells /* 6463034097aSDavid Howells * look up the first VMA in which addr resides, NULL if none 647c1e8d7c6SMichel Lespinasse * - should be called with mm->mmap_lock at least held readlocked 6483034097aSDavid Howells */ 6493034097aSDavid Howells struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) 6503034097aSDavid Howells { 6518feae131SDavid Howells struct vm_area_struct *vma; 652*524e00b3SLiam R. Howlett MA_STATE(mas, &mm->mm_mt, addr, addr); 6533034097aSDavid Howells 6548feae131SDavid Howells /* check the cache first */ 655615d6e87SDavidlohr Bueso vma = vmacache_find(mm, addr); 656615d6e87SDavidlohr Bueso if (likely(vma)) 6578feae131SDavid Howells return vma; 6588feae131SDavid Howells 659*524e00b3SLiam R. Howlett vma = mas_walk(&mas); 6603034097aSDavid Howells 661*524e00b3SLiam R. Howlett if (vma) 662*524e00b3SLiam R. Howlett vmacache_update(addr, vma); 663*524e00b3SLiam R. Howlett 664*524e00b3SLiam R. Howlett return vma; 6653034097aSDavid Howells } 6663034097aSDavid Howells EXPORT_SYMBOL(find_vma); 6673034097aSDavid Howells 6683034097aSDavid Howells /* 669930e652aSDavid Howells * find a VMA 670930e652aSDavid Howells * - we don't extend stack VMAs under NOMMU conditions 671930e652aSDavid Howells */ 672930e652aSDavid Howells struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) 673930e652aSDavid Howells { 6747561e8caSDavid Howells return find_vma(mm, addr); 675930e652aSDavid Howells } 676930e652aSDavid Howells 6778feae131SDavid Howells /* 6788feae131SDavid Howells * expand a stack to a given address 6798feae131SDavid Howells * - not supported under NOMMU conditions 6808feae131SDavid Howells */ 68157c8f63eSGreg Ungerer int expand_stack(struct vm_area_struct *vma, unsigned long address) 68257c8f63eSGreg Ungerer { 68357c8f63eSGreg Ungerer return -ENOMEM; 68457c8f63eSGreg Ungerer } 68557c8f63eSGreg Ungerer 686930e652aSDavid Howells /* 6876fa5f80bSDavid Howells * look up the first VMA exactly that exactly matches addr 688c1e8d7c6SMichel Lespinasse * - should be called with mm->mmap_lock at least held readlocked 6896fa5f80bSDavid Howells */ 6908feae131SDavid Howells static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, 6918feae131SDavid Howells unsigned long addr, 6928feae131SDavid Howells unsigned long len) 6931da177e4SLinus Torvalds { 6941da177e4SLinus Torvalds struct vm_area_struct *vma; 6958feae131SDavid Howells unsigned long end = addr + len; 696*524e00b3SLiam R. Howlett MA_STATE(mas, &mm->mm_mt, addr, addr); 6971da177e4SLinus Torvalds 6988feae131SDavid Howells /* check the cache first */ 699615d6e87SDavidlohr Bueso vma = vmacache_find_exact(mm, addr, end); 700615d6e87SDavidlohr Bueso if (vma) 7011da177e4SLinus Torvalds return vma; 7028feae131SDavid Howells 703*524e00b3SLiam R. Howlett vma = mas_walk(&mas); 704*524e00b3SLiam R. Howlett if (!vma) 7058feae131SDavid Howells return NULL; 706*524e00b3SLiam R. Howlett if (vma->vm_start != addr) 707*524e00b3SLiam R. Howlett return NULL; 708*524e00b3SLiam R. Howlett if (vma->vm_end != end) 709*524e00b3SLiam R. Howlett return NULL; 710*524e00b3SLiam R. Howlett 711615d6e87SDavidlohr Bueso vmacache_update(addr, vma); 7128feae131SDavid Howells return vma; 7138feae131SDavid Howells } 7141da177e4SLinus Torvalds 7153034097aSDavid Howells /* 7161da177e4SLinus Torvalds * determine whether a mapping should be permitted and, if so, what sort of 7171da177e4SLinus Torvalds * mapping we're capable of supporting 7181da177e4SLinus Torvalds */ 7191da177e4SLinus Torvalds static int validate_mmap_request(struct file *file, 7201da177e4SLinus Torvalds unsigned long addr, 7211da177e4SLinus Torvalds unsigned long len, 7221da177e4SLinus Torvalds unsigned long prot, 7231da177e4SLinus Torvalds unsigned long flags, 7241da177e4SLinus Torvalds unsigned long pgoff, 7251da177e4SLinus Torvalds unsigned long *_capabilities) 7261da177e4SLinus Torvalds { 7278feae131SDavid Howells unsigned long capabilities, rlen; 7281da177e4SLinus Torvalds int ret; 7291da177e4SLinus Torvalds 7301da177e4SLinus Torvalds /* do the simple checks first */ 73122cc877bSLeon Romanovsky if (flags & MAP_FIXED) 7321da177e4SLinus Torvalds return -EINVAL; 7331da177e4SLinus Torvalds 7341da177e4SLinus Torvalds if ((flags & MAP_TYPE) != MAP_PRIVATE && 7351da177e4SLinus Torvalds (flags & MAP_TYPE) != MAP_SHARED) 7361da177e4SLinus Torvalds return -EINVAL; 7371da177e4SLinus Torvalds 738f81cff0dSMike Frysinger if (!len) 7391da177e4SLinus Torvalds return -EINVAL; 7401da177e4SLinus Torvalds 741f81cff0dSMike Frysinger /* Careful about overflows.. */ 7428feae131SDavid Howells rlen = PAGE_ALIGN(len); 7438feae131SDavid Howells if (!rlen || rlen > TASK_SIZE) 744f81cff0dSMike Frysinger return -ENOMEM; 745f81cff0dSMike Frysinger 7461da177e4SLinus Torvalds /* offset overflow? */ 7478feae131SDavid Howells if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) 748f81cff0dSMike Frysinger return -EOVERFLOW; 7491da177e4SLinus Torvalds 7501da177e4SLinus Torvalds if (file) { 7511da177e4SLinus Torvalds /* files must support mmap */ 75272c2d531SAl Viro if (!file->f_op->mmap) 7531da177e4SLinus Torvalds return -ENODEV; 7541da177e4SLinus Torvalds 7551da177e4SLinus Torvalds /* work out if what we've got could possibly be shared 7561da177e4SLinus Torvalds * - we support chardevs that provide their own "memory" 7571da177e4SLinus Torvalds * - we support files/blockdevs that are memory backed 7581da177e4SLinus Torvalds */ 759b4caecd4SChristoph Hellwig if (file->f_op->mmap_capabilities) { 760b4caecd4SChristoph Hellwig capabilities = file->f_op->mmap_capabilities(file); 761b4caecd4SChristoph Hellwig } else { 7621da177e4SLinus Torvalds /* no explicit capabilities set, so assume some 7631da177e4SLinus Torvalds * defaults */ 764496ad9aaSAl Viro switch (file_inode(file)->i_mode & S_IFMT) { 7651da177e4SLinus Torvalds case S_IFREG: 7661da177e4SLinus Torvalds case S_IFBLK: 767b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 7681da177e4SLinus Torvalds break; 7691da177e4SLinus Torvalds 7701da177e4SLinus Torvalds case S_IFCHR: 7711da177e4SLinus Torvalds capabilities = 772b4caecd4SChristoph Hellwig NOMMU_MAP_DIRECT | 773b4caecd4SChristoph Hellwig NOMMU_MAP_READ | 774b4caecd4SChristoph Hellwig NOMMU_MAP_WRITE; 7751da177e4SLinus Torvalds break; 7761da177e4SLinus Torvalds 7771da177e4SLinus Torvalds default: 7781da177e4SLinus Torvalds return -EINVAL; 7791da177e4SLinus Torvalds } 7801da177e4SLinus Torvalds } 7811da177e4SLinus Torvalds 7821da177e4SLinus Torvalds /* eliminate any capabilities that we can't support on this 7831da177e4SLinus Torvalds * device */ 7841da177e4SLinus Torvalds if (!file->f_op->get_unmapped_area) 785b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 7866e242a1cSAl Viro if (!(file->f_mode & FMODE_CAN_READ)) 787b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 7881da177e4SLinus Torvalds 78928d7a6aeSGraff Yang /* The file shall have been opened with read permission. */ 79028d7a6aeSGraff Yang if (!(file->f_mode & FMODE_READ)) 79128d7a6aeSGraff Yang return -EACCES; 79228d7a6aeSGraff Yang 7931da177e4SLinus Torvalds if (flags & MAP_SHARED) { 7941da177e4SLinus Torvalds /* do checks for writing, appending and locking */ 7951da177e4SLinus Torvalds if ((prot & PROT_WRITE) && 7961da177e4SLinus Torvalds !(file->f_mode & FMODE_WRITE)) 7971da177e4SLinus Torvalds return -EACCES; 7981da177e4SLinus Torvalds 799496ad9aaSAl Viro if (IS_APPEND(file_inode(file)) && 8001da177e4SLinus Torvalds (file->f_mode & FMODE_WRITE)) 8011da177e4SLinus Torvalds return -EACCES; 8021da177e4SLinus Torvalds 803b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 8041da177e4SLinus Torvalds return -ENODEV; 8051da177e4SLinus Torvalds 8061da177e4SLinus Torvalds /* we mustn't privatise shared mappings */ 807b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 808ac714904SChoi Gi-yong } else { 8091da177e4SLinus Torvalds /* we're going to read the file into private memory we 8101da177e4SLinus Torvalds * allocate */ 811b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 8121da177e4SLinus Torvalds return -ENODEV; 8131da177e4SLinus Torvalds 8141da177e4SLinus Torvalds /* we don't permit a private writable mapping to be 8151da177e4SLinus Torvalds * shared with the backing device */ 8161da177e4SLinus Torvalds if (prot & PROT_WRITE) 817b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8181da177e4SLinus Torvalds } 8191da177e4SLinus Torvalds 820b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 821b4caecd4SChristoph Hellwig if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) || 822b4caecd4SChristoph Hellwig ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) || 823b4caecd4SChristoph Hellwig ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC)) 8243c7b2045SBernd Schmidt ) { 825b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8263c7b2045SBernd Schmidt if (flags & MAP_SHARED) { 82722cc877bSLeon Romanovsky pr_warn("MAP_SHARED not completely supported on !MMU\n"); 8283c7b2045SBernd Schmidt return -EINVAL; 8293c7b2045SBernd Schmidt } 8303c7b2045SBernd Schmidt } 8313c7b2045SBernd Schmidt } 8323c7b2045SBernd Schmidt 8331da177e4SLinus Torvalds /* handle executable mappings and implied executable 8341da177e4SLinus Torvalds * mappings */ 83590f8572bSEric W. Biederman if (path_noexec(&file->f_path)) { 8361da177e4SLinus Torvalds if (prot & PROT_EXEC) 8371da177e4SLinus Torvalds return -EPERM; 838ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { 8391da177e4SLinus Torvalds /* handle implication of PROT_EXEC by PROT_READ */ 8401da177e4SLinus Torvalds if (current->personality & READ_IMPLIES_EXEC) { 841b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_EXEC) 8421da177e4SLinus Torvalds prot |= PROT_EXEC; 8431da177e4SLinus Torvalds } 844ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && 8451da177e4SLinus Torvalds (prot & PROT_EXEC) && 846b4caecd4SChristoph Hellwig !(capabilities & NOMMU_MAP_EXEC) 8471da177e4SLinus Torvalds ) { 8481da177e4SLinus Torvalds /* backing file is not executable, try to copy */ 849b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8501da177e4SLinus Torvalds } 851ac714904SChoi Gi-yong } else { 8521da177e4SLinus Torvalds /* anonymous mappings are always memory backed and can be 8531da177e4SLinus Torvalds * privately mapped 8541da177e4SLinus Torvalds */ 855b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 8561da177e4SLinus Torvalds 8571da177e4SLinus Torvalds /* handle PROT_EXEC implication by PROT_READ */ 8581da177e4SLinus Torvalds if ((prot & PROT_READ) && 8591da177e4SLinus Torvalds (current->personality & READ_IMPLIES_EXEC)) 8601da177e4SLinus Torvalds prot |= PROT_EXEC; 8611da177e4SLinus Torvalds } 8621da177e4SLinus Torvalds 8631da177e4SLinus Torvalds /* allow the security API to have its say */ 864e5467859SAl Viro ret = security_mmap_addr(addr); 865e5467859SAl Viro if (ret < 0) 866e5467859SAl Viro return ret; 8671da177e4SLinus Torvalds 8681da177e4SLinus Torvalds /* looks okay */ 8691da177e4SLinus Torvalds *_capabilities = capabilities; 8701da177e4SLinus Torvalds return 0; 8711da177e4SLinus Torvalds } 8721da177e4SLinus Torvalds 8731da177e4SLinus Torvalds /* 8741da177e4SLinus Torvalds * we've determined that we can make the mapping, now translate what we 8751da177e4SLinus Torvalds * now know into VMA flags 8761da177e4SLinus Torvalds */ 8771da177e4SLinus Torvalds static unsigned long determine_vm_flags(struct file *file, 8781da177e4SLinus Torvalds unsigned long prot, 8791da177e4SLinus Torvalds unsigned long flags, 8801da177e4SLinus Torvalds unsigned long capabilities) 8811da177e4SLinus Torvalds { 8821da177e4SLinus Torvalds unsigned long vm_flags; 8831da177e4SLinus Torvalds 884e6bfb709SDave Hansen vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags); 8851da177e4SLinus Torvalds /* vm_flags |= mm->def_flags; */ 8861da177e4SLinus Torvalds 887b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) { 8881da177e4SLinus Torvalds /* attempt to share read-only copies of mapped file chunks */ 8893c7b2045SBernd Schmidt vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; 8901da177e4SLinus Torvalds if (file && !(prot & PROT_WRITE)) 8911da177e4SLinus Torvalds vm_flags |= VM_MAYSHARE; 8923c7b2045SBernd Schmidt } else { 8931da177e4SLinus Torvalds /* overlay a shareable mapping on the backing device or inode 8941da177e4SLinus Torvalds * if possible - used for chardevs, ramfs/tmpfs/shmfs and 8951da177e4SLinus Torvalds * romfs/cramfs */ 896b4caecd4SChristoph Hellwig vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS); 8971da177e4SLinus Torvalds if (flags & MAP_SHARED) 8983c7b2045SBernd Schmidt vm_flags |= VM_SHARED; 8991da177e4SLinus Torvalds } 9001da177e4SLinus Torvalds 9011da177e4SLinus Torvalds /* refuse to let anyone share private mappings with this process if 9021da177e4SLinus Torvalds * it's being traced - otherwise breakpoints set in it may interfere 9031da177e4SLinus Torvalds * with another untraced process 9041da177e4SLinus Torvalds */ 905a288eeccSTejun Heo if ((flags & MAP_PRIVATE) && current->ptrace) 9061da177e4SLinus Torvalds vm_flags &= ~VM_MAYSHARE; 9071da177e4SLinus Torvalds 9081da177e4SLinus Torvalds return vm_flags; 9091da177e4SLinus Torvalds } 9101da177e4SLinus Torvalds 9111da177e4SLinus Torvalds /* 9128feae131SDavid Howells * set up a shared mapping on a file (the driver or filesystem provides and 9138feae131SDavid Howells * pins the storage) 9141da177e4SLinus Torvalds */ 9158feae131SDavid Howells static int do_mmap_shared_file(struct vm_area_struct *vma) 9161da177e4SLinus Torvalds { 9171da177e4SLinus Torvalds int ret; 9181da177e4SLinus Torvalds 919f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 920dd8632a1SPaul Mundt if (ret == 0) { 921dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 922645d83c5SDavid Howells return 0; 923dd8632a1SPaul Mundt } 9241da177e4SLinus Torvalds if (ret != -ENOSYS) 9251da177e4SLinus Torvalds return ret; 9261da177e4SLinus Torvalds 9273fa30460SDavid Howells /* getting -ENOSYS indicates that direct mmap isn't possible (as 9283fa30460SDavid Howells * opposed to tried but failed) so we can only give a suitable error as 9293fa30460SDavid Howells * it's not possible to make a private copy if MAP_SHARED was given */ 9301da177e4SLinus Torvalds return -ENODEV; 9311da177e4SLinus Torvalds } 9321da177e4SLinus Torvalds 9331da177e4SLinus Torvalds /* 9341da177e4SLinus Torvalds * set up a private mapping or an anonymous shared mapping 9351da177e4SLinus Torvalds */ 9368feae131SDavid Howells static int do_mmap_private(struct vm_area_struct *vma, 9378feae131SDavid Howells struct vm_region *region, 938645d83c5SDavid Howells unsigned long len, 939645d83c5SDavid Howells unsigned long capabilities) 9401da177e4SLinus Torvalds { 941dbc8358cSJoonsoo Kim unsigned long total, point; 9421da177e4SLinus Torvalds void *base; 9438feae131SDavid Howells int ret, order; 9441da177e4SLinus Torvalds 9451da177e4SLinus Torvalds /* invoke the file's mapping function so that it can keep track of 9461da177e4SLinus Torvalds * shared mappings on devices or memory 9471da177e4SLinus Torvalds * - VM_MAYSHARE will be set if it may attempt to share 9481da177e4SLinus Torvalds */ 949b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 950f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 951dd8632a1SPaul Mundt if (ret == 0) { 9521da177e4SLinus Torvalds /* shouldn't return success if we're not sharing */ 953dd8632a1SPaul Mundt BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); 954dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 955645d83c5SDavid Howells return 0; 9561da177e4SLinus Torvalds } 957dd8632a1SPaul Mundt if (ret != -ENOSYS) 958dd8632a1SPaul Mundt return ret; 9591da177e4SLinus Torvalds 9601da177e4SLinus Torvalds /* getting an ENOSYS error indicates that direct mmap isn't 9611da177e4SLinus Torvalds * possible (as opposed to tried but failed) so we'll try to 9621da177e4SLinus Torvalds * make a private copy of the data and map that instead */ 9631da177e4SLinus Torvalds } 9641da177e4SLinus Torvalds 9658feae131SDavid Howells 9661da177e4SLinus Torvalds /* allocate some memory to hold the mapping 9671da177e4SLinus Torvalds * - note that this may not return a page-aligned address if the object 9681da177e4SLinus Torvalds * we're allocating is smaller than a page 9691da177e4SLinus Torvalds */ 970f67d9b15SBob Liu order = get_order(len); 9718feae131SDavid Howells total = 1 << order; 972f67d9b15SBob Liu point = len >> PAGE_SHIFT; 973dd8632a1SPaul Mundt 974dbc8358cSJoonsoo Kim /* we don't want to allocate a power-of-2 sized page set */ 97522cc877bSLeon Romanovsky if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) 976dbc8358cSJoonsoo Kim total = point; 9778feae131SDavid Howells 978da616534SJoonsoo Kim base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL); 979dbc8358cSJoonsoo Kim if (!base) 980dbc8358cSJoonsoo Kim goto enomem; 9818feae131SDavid Howells 982dbc8358cSJoonsoo Kim atomic_long_add(total, &mmap_pages_allocated); 983dbc8358cSJoonsoo Kim 9848feae131SDavid Howells region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; 9858feae131SDavid Howells region->vm_start = (unsigned long) base; 986f67d9b15SBob Liu region->vm_end = region->vm_start + len; 987dd8632a1SPaul Mundt region->vm_top = region->vm_start + (total << PAGE_SHIFT); 9888feae131SDavid Howells 9898feae131SDavid Howells vma->vm_start = region->vm_start; 9908feae131SDavid Howells vma->vm_end = region->vm_start + len; 9911da177e4SLinus Torvalds 9921da177e4SLinus Torvalds if (vma->vm_file) { 9931da177e4SLinus Torvalds /* read the contents of a file into the copy */ 9941da177e4SLinus Torvalds loff_t fpos; 9951da177e4SLinus Torvalds 9961da177e4SLinus Torvalds fpos = vma->vm_pgoff; 9971da177e4SLinus Torvalds fpos <<= PAGE_SHIFT; 9981da177e4SLinus Torvalds 999b4bf802aSChristoph Hellwig ret = kernel_read(vma->vm_file, base, len, &fpos); 10001da177e4SLinus Torvalds if (ret < 0) 10011da177e4SLinus Torvalds goto error_free; 10021da177e4SLinus Torvalds 10031da177e4SLinus Torvalds /* clear the last little bit */ 1004f67d9b15SBob Liu if (ret < len) 1005f67d9b15SBob Liu memset(base + ret, 0, len - ret); 10061da177e4SLinus Torvalds 1007bfd40eafSKirill A. Shutemov } else { 1008bfd40eafSKirill A. Shutemov vma_set_anonymous(vma); 10091da177e4SLinus Torvalds } 10101da177e4SLinus Torvalds 10111da177e4SLinus Torvalds return 0; 10121da177e4SLinus Torvalds 10131da177e4SLinus Torvalds error_free: 10147223bb4aSNamhyung Kim free_page_series(region->vm_start, region->vm_top); 10158feae131SDavid Howells region->vm_start = vma->vm_start = 0; 10168feae131SDavid Howells region->vm_end = vma->vm_end = 0; 1017dd8632a1SPaul Mundt region->vm_top = 0; 10181da177e4SLinus Torvalds return ret; 10191da177e4SLinus Torvalds 10201da177e4SLinus Torvalds enomem: 1021b1de0d13SMitchel Humpherys pr_err("Allocation of length %lu from process %d (%s) failed\n", 102205ae6fa3SGreg Ungerer len, current->pid, current->comm); 10239af744d7SMichal Hocko show_free_areas(0, NULL); 10241da177e4SLinus Torvalds return -ENOMEM; 10251da177e4SLinus Torvalds } 10261da177e4SLinus Torvalds 10271da177e4SLinus Torvalds /* 10281da177e4SLinus Torvalds * handle mapping creation for uClinux 10291da177e4SLinus Torvalds */ 10301fcfd8dbSOleg Nesterov unsigned long do_mmap(struct file *file, 10311da177e4SLinus Torvalds unsigned long addr, 10321da177e4SLinus Torvalds unsigned long len, 10331da177e4SLinus Torvalds unsigned long prot, 10341da177e4SLinus Torvalds unsigned long flags, 1035bebeb3d6SMichel Lespinasse unsigned long pgoff, 1036897ab3e0SMike Rapoport unsigned long *populate, 1037897ab3e0SMike Rapoport struct list_head *uf) 10381da177e4SLinus Torvalds { 10398feae131SDavid Howells struct vm_area_struct *vma; 10408feae131SDavid Howells struct vm_region *region; 10411da177e4SLinus Torvalds struct rb_node *rb; 104245e55300SPeter Collingbourne vm_flags_t vm_flags; 10431fcfd8dbSOleg Nesterov unsigned long capabilities, result; 10441da177e4SLinus Torvalds int ret; 10451da177e4SLinus Torvalds 104641badc15SMichel Lespinasse *populate = 0; 1047bebeb3d6SMichel Lespinasse 10481da177e4SLinus Torvalds /* decide whether we should attempt the mapping, and if so what sort of 10491da177e4SLinus Torvalds * mapping */ 10501da177e4SLinus Torvalds ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, 10511da177e4SLinus Torvalds &capabilities); 105222cc877bSLeon Romanovsky if (ret < 0) 10531da177e4SLinus Torvalds return ret; 10541da177e4SLinus Torvalds 105506aab5a3SDavid Howells /* we ignore the address hint */ 105606aab5a3SDavid Howells addr = 0; 1057f67d9b15SBob Liu len = PAGE_ALIGN(len); 105806aab5a3SDavid Howells 10591da177e4SLinus Torvalds /* we've determined that we can make the mapping, now translate what we 10601da177e4SLinus Torvalds * now know into VMA flags */ 106145e55300SPeter Collingbourne vm_flags = determine_vm_flags(file, prot, flags, capabilities); 10621da177e4SLinus Torvalds 10638feae131SDavid Howells /* we're going to need to record the mapping */ 10648feae131SDavid Howells region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); 10658feae131SDavid Howells if (!region) 10668feae131SDavid Howells goto error_getting_region; 10671da177e4SLinus Torvalds 1068490fc053SLinus Torvalds vma = vm_area_alloc(current->mm); 10698feae131SDavid Howells if (!vma) 10708feae131SDavid Howells goto error_getting_vma; 10711da177e4SLinus Torvalds 10721e2ae599SDavid Howells region->vm_usage = 1; 10738feae131SDavid Howells region->vm_flags = vm_flags; 10748feae131SDavid Howells region->vm_pgoff = pgoff; 10758feae131SDavid Howells 10768feae131SDavid Howells vma->vm_flags = vm_flags; 10778feae131SDavid Howells vma->vm_pgoff = pgoff; 10788feae131SDavid Howells 10798feae131SDavid Howells if (file) { 1080cb0942b8SAl Viro region->vm_file = get_file(file); 1081cb0942b8SAl Viro vma->vm_file = get_file(file); 10828feae131SDavid Howells } 10838feae131SDavid Howells 10848feae131SDavid Howells down_write(&nommu_region_sem); 10858feae131SDavid Howells 10868feae131SDavid Howells /* if we want to share, we need to check for regions created by other 10871da177e4SLinus Torvalds * mmap() calls that overlap with our proposed mapping 10888feae131SDavid Howells * - we can only share with a superset match on most regular files 10891da177e4SLinus Torvalds * - shared mappings on character devices and memory backed files are 10901da177e4SLinus Torvalds * permitted to overlap inexactly as far as we are concerned for in 10911da177e4SLinus Torvalds * these cases, sharing is handled in the driver or filesystem rather 10921da177e4SLinus Torvalds * than here 10931da177e4SLinus Torvalds */ 10941da177e4SLinus Torvalds if (vm_flags & VM_MAYSHARE) { 10958feae131SDavid Howells struct vm_region *pregion; 10968feae131SDavid Howells unsigned long pglen, rpglen, pgend, rpgend, start; 10971da177e4SLinus Torvalds 10988feae131SDavid Howells pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 10998feae131SDavid Howells pgend = pgoff + pglen; 1100165b2392SDavid Howells 11018feae131SDavid Howells for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { 11028feae131SDavid Howells pregion = rb_entry(rb, struct vm_region, vm_rb); 11031da177e4SLinus Torvalds 11048feae131SDavid Howells if (!(pregion->vm_flags & VM_MAYSHARE)) 11051da177e4SLinus Torvalds continue; 11061da177e4SLinus Torvalds 11071da177e4SLinus Torvalds /* search for overlapping mappings on the same file */ 1108496ad9aaSAl Viro if (file_inode(pregion->vm_file) != 1109496ad9aaSAl Viro file_inode(file)) 11101da177e4SLinus Torvalds continue; 11111da177e4SLinus Torvalds 11128feae131SDavid Howells if (pregion->vm_pgoff >= pgend) 11131da177e4SLinus Torvalds continue; 11141da177e4SLinus Torvalds 11158feae131SDavid Howells rpglen = pregion->vm_end - pregion->vm_start; 11168feae131SDavid Howells rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; 11178feae131SDavid Howells rpgend = pregion->vm_pgoff + rpglen; 11188feae131SDavid Howells if (pgoff >= rpgend) 11191da177e4SLinus Torvalds continue; 11201da177e4SLinus Torvalds 11218feae131SDavid Howells /* handle inexactly overlapping matches between 11228feae131SDavid Howells * mappings */ 11238feae131SDavid Howells if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && 11248feae131SDavid Howells !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { 11258feae131SDavid Howells /* new mapping is not a subset of the region */ 1126b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 11271da177e4SLinus Torvalds goto sharing_violation; 11281da177e4SLinus Torvalds continue; 11291da177e4SLinus Torvalds } 11301da177e4SLinus Torvalds 11318feae131SDavid Howells /* we've found a region we can share */ 11321e2ae599SDavid Howells pregion->vm_usage++; 11338feae131SDavid Howells vma->vm_region = pregion; 11348feae131SDavid Howells start = pregion->vm_start; 11358feae131SDavid Howells start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; 11368feae131SDavid Howells vma->vm_start = start; 11378feae131SDavid Howells vma->vm_end = start + len; 11381da177e4SLinus Torvalds 113922cc877bSLeon Romanovsky if (pregion->vm_flags & VM_MAPPED_COPY) 11408feae131SDavid Howells vma->vm_flags |= VM_MAPPED_COPY; 114122cc877bSLeon Romanovsky else { 11428feae131SDavid Howells ret = do_mmap_shared_file(vma); 11438feae131SDavid Howells if (ret < 0) { 11448feae131SDavid Howells vma->vm_region = NULL; 11458feae131SDavid Howells vma->vm_start = 0; 11468feae131SDavid Howells vma->vm_end = 0; 11471e2ae599SDavid Howells pregion->vm_usage--; 11488feae131SDavid Howells pregion = NULL; 11498feae131SDavid Howells goto error_just_free; 11501da177e4SLinus Torvalds } 11518feae131SDavid Howells } 11528feae131SDavid Howells fput(region->vm_file); 11538feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 11548feae131SDavid Howells region = pregion; 11558feae131SDavid Howells result = start; 11568feae131SDavid Howells goto share; 11578feae131SDavid Howells } 11581da177e4SLinus Torvalds 11591da177e4SLinus Torvalds /* obtain the address at which to make a shared mapping 11601da177e4SLinus Torvalds * - this is the hook for quasi-memory character devices to 11611da177e4SLinus Torvalds * tell us the location of a shared mapping 11621da177e4SLinus Torvalds */ 1163b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 11641da177e4SLinus Torvalds addr = file->f_op->get_unmapped_area(file, addr, len, 11651da177e4SLinus Torvalds pgoff, flags); 1166bb005a59SNamhyung Kim if (IS_ERR_VALUE(addr)) { 11671da177e4SLinus Torvalds ret = addr; 1168bb005a59SNamhyung Kim if (ret != -ENOSYS) 11698feae131SDavid Howells goto error_just_free; 11701da177e4SLinus Torvalds 11711da177e4SLinus Torvalds /* the driver refused to tell us where to site 11721da177e4SLinus Torvalds * the mapping so we'll have to attempt to copy 11731da177e4SLinus Torvalds * it */ 1174bb005a59SNamhyung Kim ret = -ENODEV; 1175b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 11768feae131SDavid Howells goto error_just_free; 11771da177e4SLinus Torvalds 1178b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 11798feae131SDavid Howells } else { 11808feae131SDavid Howells vma->vm_start = region->vm_start = addr; 11818feae131SDavid Howells vma->vm_end = region->vm_end = addr + len; 11821da177e4SLinus Torvalds } 11831da177e4SLinus Torvalds } 11841da177e4SLinus Torvalds } 11851da177e4SLinus Torvalds 11868feae131SDavid Howells vma->vm_region = region; 11871da177e4SLinus Torvalds 1188645d83c5SDavid Howells /* set up the mapping 1189b4caecd4SChristoph Hellwig * - the region is filled in if NOMMU_MAP_DIRECT is still set 1190645d83c5SDavid Howells */ 11911da177e4SLinus Torvalds if (file && vma->vm_flags & VM_SHARED) 11928feae131SDavid Howells ret = do_mmap_shared_file(vma); 11931da177e4SLinus Torvalds else 1194645d83c5SDavid Howells ret = do_mmap_private(vma, region, len, capabilities); 11951da177e4SLinus Torvalds if (ret < 0) 1196645d83c5SDavid Howells goto error_just_free; 1197645d83c5SDavid Howells add_nommu_region(region); 11988feae131SDavid Howells 1199ea637639SJie Zhang /* clear anonymous mappings that don't ask for uninitialized data */ 12000bf5f949SChristoph Hellwig if (!vma->vm_file && 12010bf5f949SChristoph Hellwig (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) || 12020bf5f949SChristoph Hellwig !(flags & MAP_UNINITIALIZED))) 1203ea637639SJie Zhang memset((void *)region->vm_start, 0, 1204ea637639SJie Zhang region->vm_end - region->vm_start); 1205ea637639SJie Zhang 12061da177e4SLinus Torvalds /* okay... we have a mapping; now we have to register it */ 12078feae131SDavid Howells result = vma->vm_start; 12081da177e4SLinus Torvalds 12091da177e4SLinus Torvalds current->mm->total_vm += len >> PAGE_SHIFT; 12101da177e4SLinus Torvalds 12118feae131SDavid Howells share: 12128feae131SDavid Howells add_vma_to_mm(current->mm, vma); 12131da177e4SLinus Torvalds 1214cfe79c00SMike Frysinger /* we flush the region from the icache only when the first executable 1215cfe79c00SMike Frysinger * mapping of it is made */ 1216cfe79c00SMike Frysinger if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { 1217a75a2df6SChristoph Hellwig flush_icache_user_range(region->vm_start, region->vm_end); 1218cfe79c00SMike Frysinger region->vm_icache_flushed = true; 1219cfe79c00SMike Frysinger } 12201da177e4SLinus Torvalds 1221cfe79c00SMike Frysinger up_write(&nommu_region_sem); 12221da177e4SLinus Torvalds 12238feae131SDavid Howells return result; 12241da177e4SLinus Torvalds 12258feae131SDavid Howells error_just_free: 12268feae131SDavid Howells up_write(&nommu_region_sem); 12278feae131SDavid Howells error: 122889a86402SDavid Howells if (region->vm_file) 12298feae131SDavid Howells fput(region->vm_file); 12308feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 123189a86402SDavid Howells if (vma->vm_file) 12328feae131SDavid Howells fput(vma->vm_file); 12333928d4f5SLinus Torvalds vm_area_free(vma); 12341da177e4SLinus Torvalds return ret; 12351da177e4SLinus Torvalds 12361da177e4SLinus Torvalds sharing_violation: 12378feae131SDavid Howells up_write(&nommu_region_sem); 123822cc877bSLeon Romanovsky pr_warn("Attempt to share mismatched mappings\n"); 12398feae131SDavid Howells ret = -EINVAL; 12408feae131SDavid Howells goto error; 12411da177e4SLinus Torvalds 12421da177e4SLinus Torvalds error_getting_vma: 12438feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 124422cc877bSLeon Romanovsky pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n", 12451da177e4SLinus Torvalds len, current->pid); 12469af744d7SMichal Hocko show_free_areas(0, NULL); 12471da177e4SLinus Torvalds return -ENOMEM; 12481da177e4SLinus Torvalds 12498feae131SDavid Howells error_getting_region: 125022cc877bSLeon Romanovsky pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n", 12511da177e4SLinus Torvalds len, current->pid); 12529af744d7SMichal Hocko show_free_areas(0, NULL); 12531da177e4SLinus Torvalds return -ENOMEM; 12541da177e4SLinus Torvalds } 12556be5ceb0SLinus Torvalds 1256a90f590aSDominik Brodowski unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, 1257a90f590aSDominik Brodowski unsigned long prot, unsigned long flags, 1258a90f590aSDominik Brodowski unsigned long fd, unsigned long pgoff) 125966f0dc48SHugh Dickins { 126066f0dc48SHugh Dickins struct file *file = NULL; 126166f0dc48SHugh Dickins unsigned long retval = -EBADF; 126266f0dc48SHugh Dickins 1263120a795dSAl Viro audit_mmap_fd(fd, flags); 126466f0dc48SHugh Dickins if (!(flags & MAP_ANONYMOUS)) { 126566f0dc48SHugh Dickins file = fget(fd); 126666f0dc48SHugh Dickins if (!file) 126766f0dc48SHugh Dickins goto out; 126866f0dc48SHugh Dickins } 126966f0dc48SHugh Dickins 1270ad1ed293SGreg Ungerer retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); 127166f0dc48SHugh Dickins 127266f0dc48SHugh Dickins if (file) 127366f0dc48SHugh Dickins fput(file); 127466f0dc48SHugh Dickins out: 127566f0dc48SHugh Dickins return retval; 127666f0dc48SHugh Dickins } 127766f0dc48SHugh Dickins 1278a90f590aSDominik Brodowski SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 1279a90f590aSDominik Brodowski unsigned long, prot, unsigned long, flags, 1280a90f590aSDominik Brodowski unsigned long, fd, unsigned long, pgoff) 1281a90f590aSDominik Brodowski { 1282a90f590aSDominik Brodowski return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); 1283a90f590aSDominik Brodowski } 1284a90f590aSDominik Brodowski 1285a4679373SChristoph Hellwig #ifdef __ARCH_WANT_SYS_OLD_MMAP 1286a4679373SChristoph Hellwig struct mmap_arg_struct { 1287a4679373SChristoph Hellwig unsigned long addr; 1288a4679373SChristoph Hellwig unsigned long len; 1289a4679373SChristoph Hellwig unsigned long prot; 1290a4679373SChristoph Hellwig unsigned long flags; 1291a4679373SChristoph Hellwig unsigned long fd; 1292a4679373SChristoph Hellwig unsigned long offset; 1293a4679373SChristoph Hellwig }; 1294a4679373SChristoph Hellwig 1295a4679373SChristoph Hellwig SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) 1296a4679373SChristoph Hellwig { 1297a4679373SChristoph Hellwig struct mmap_arg_struct a; 1298a4679373SChristoph Hellwig 1299a4679373SChristoph Hellwig if (copy_from_user(&a, arg, sizeof(a))) 1300a4679373SChristoph Hellwig return -EFAULT; 13011824cb75SAlexander Kuleshov if (offset_in_page(a.offset)) 1302a4679373SChristoph Hellwig return -EINVAL; 1303a4679373SChristoph Hellwig 1304a90f590aSDominik Brodowski return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, 1305a4679373SChristoph Hellwig a.offset >> PAGE_SHIFT); 1306a4679373SChristoph Hellwig } 1307a4679373SChristoph Hellwig #endif /* __ARCH_WANT_SYS_OLD_MMAP */ 1308a4679373SChristoph Hellwig 13091da177e4SLinus Torvalds /* 13108feae131SDavid Howells * split a vma into two pieces at address 'addr', a new vma is allocated either 13118feae131SDavid Howells * for the first part or the tail. 13121da177e4SLinus Torvalds */ 13138feae131SDavid Howells int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 13148feae131SDavid Howells unsigned long addr, int new_below) 13151da177e4SLinus Torvalds { 13168feae131SDavid Howells struct vm_area_struct *new; 13178feae131SDavid Howells struct vm_region *region; 13188feae131SDavid Howells unsigned long npages; 13191da177e4SLinus Torvalds 1320779c1023SDavid Howells /* we're only permitted to split anonymous regions (these should have 1321779c1023SDavid Howells * only a single usage on the region) */ 1322779c1023SDavid Howells if (vma->vm_file) 13238feae131SDavid Howells return -ENOMEM; 13241da177e4SLinus Torvalds 13258feae131SDavid Howells if (mm->map_count >= sysctl_max_map_count) 13268feae131SDavid Howells return -ENOMEM; 13271da177e4SLinus Torvalds 13288feae131SDavid Howells region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); 13298feae131SDavid Howells if (!region) 13308feae131SDavid Howells return -ENOMEM; 13318feae131SDavid Howells 13323928d4f5SLinus Torvalds new = vm_area_dup(vma); 13338feae131SDavid Howells if (!new) { 13348feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 13358feae131SDavid Howells return -ENOMEM; 13361da177e4SLinus Torvalds } 13371da177e4SLinus Torvalds 13388feae131SDavid Howells /* most fields are the same, copy all, and then fixup */ 13398feae131SDavid Howells *region = *vma->vm_region; 13408feae131SDavid Howells new->vm_region = region; 13418feae131SDavid Howells 13428feae131SDavid Howells npages = (addr - vma->vm_start) >> PAGE_SHIFT; 13438feae131SDavid Howells 13448feae131SDavid Howells if (new_below) { 1345dd8632a1SPaul Mundt region->vm_top = region->vm_end = new->vm_end = addr; 13468feae131SDavid Howells } else { 13478feae131SDavid Howells region->vm_start = new->vm_start = addr; 13488feae131SDavid Howells region->vm_pgoff = new->vm_pgoff += npages; 13491da177e4SLinus Torvalds } 13508feae131SDavid Howells 13518feae131SDavid Howells if (new->vm_ops && new->vm_ops->open) 13528feae131SDavid Howells new->vm_ops->open(new); 13538feae131SDavid Howells 13548feae131SDavid Howells delete_vma_from_mm(vma); 13558feae131SDavid Howells down_write(&nommu_region_sem); 13568feae131SDavid Howells delete_nommu_region(vma->vm_region); 13578feae131SDavid Howells if (new_below) { 13588feae131SDavid Howells vma->vm_region->vm_start = vma->vm_start = addr; 13598feae131SDavid Howells vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; 13608feae131SDavid Howells } else { 13618feae131SDavid Howells vma->vm_region->vm_end = vma->vm_end = addr; 1362dd8632a1SPaul Mundt vma->vm_region->vm_top = addr; 13638feae131SDavid Howells } 13648feae131SDavid Howells add_nommu_region(vma->vm_region); 13658feae131SDavid Howells add_nommu_region(new->vm_region); 13668feae131SDavid Howells up_write(&nommu_region_sem); 13678feae131SDavid Howells add_vma_to_mm(mm, vma); 13688feae131SDavid Howells add_vma_to_mm(mm, new); 13698feae131SDavid Howells return 0; 13708feae131SDavid Howells } 13718feae131SDavid Howells 13728feae131SDavid Howells /* 13738feae131SDavid Howells * shrink a VMA by removing the specified chunk from either the beginning or 13748feae131SDavid Howells * the end 13758feae131SDavid Howells */ 13768feae131SDavid Howells static int shrink_vma(struct mm_struct *mm, 13778feae131SDavid Howells struct vm_area_struct *vma, 13788feae131SDavid Howells unsigned long from, unsigned long to) 13798feae131SDavid Howells { 13808feae131SDavid Howells struct vm_region *region; 13818feae131SDavid Howells 13828feae131SDavid Howells /* adjust the VMA's pointers, which may reposition it in the MM's tree 13838feae131SDavid Howells * and list */ 13848feae131SDavid Howells delete_vma_from_mm(vma); 13858feae131SDavid Howells if (from > vma->vm_start) 13868feae131SDavid Howells vma->vm_end = from; 13878feae131SDavid Howells else 13888feae131SDavid Howells vma->vm_start = to; 13898feae131SDavid Howells add_vma_to_mm(mm, vma); 13908feae131SDavid Howells 13918feae131SDavid Howells /* cut the backing region down to size */ 13928feae131SDavid Howells region = vma->vm_region; 13931e2ae599SDavid Howells BUG_ON(region->vm_usage != 1); 13948feae131SDavid Howells 13958feae131SDavid Howells down_write(&nommu_region_sem); 13968feae131SDavid Howells delete_nommu_region(region); 1397dd8632a1SPaul Mundt if (from > region->vm_start) { 1398dd8632a1SPaul Mundt to = region->vm_top; 1399dd8632a1SPaul Mundt region->vm_top = region->vm_end = from; 1400dd8632a1SPaul Mundt } else { 14018feae131SDavid Howells region->vm_start = to; 1402dd8632a1SPaul Mundt } 14038feae131SDavid Howells add_nommu_region(region); 14048feae131SDavid Howells up_write(&nommu_region_sem); 14058feae131SDavid Howells 14068feae131SDavid Howells free_page_series(from, to); 14078feae131SDavid Howells return 0; 14081da177e4SLinus Torvalds } 14091da177e4SLinus Torvalds 14103034097aSDavid Howells /* 14113034097aSDavid Howells * release a mapping 14128feae131SDavid Howells * - under NOMMU conditions the chunk to be unmapped must be backed by a single 14138feae131SDavid Howells * VMA, though it need not cover the whole VMA 14143034097aSDavid Howells */ 1415897ab3e0SMike Rapoport int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) 14161da177e4SLinus Torvalds { 14178feae131SDavid Howells struct vm_area_struct *vma; 1418f67d9b15SBob Liu unsigned long end; 14198feae131SDavid Howells int ret; 14201da177e4SLinus Torvalds 1421f67d9b15SBob Liu len = PAGE_ALIGN(len); 14228feae131SDavid Howells if (len == 0) 14231da177e4SLinus Torvalds return -EINVAL; 14241da177e4SLinus Torvalds 1425f67d9b15SBob Liu end = start + len; 1426f67d9b15SBob Liu 14278feae131SDavid Howells /* find the first potentially overlapping VMA */ 14288feae131SDavid Howells vma = find_vma(mm, start); 14298feae131SDavid Howells if (!vma) { 1430ac714904SChoi Gi-yong static int limit; 143133e5d769SDavid Howells if (limit < 5) { 143222cc877bSLeon Romanovsky pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n", 143333e5d769SDavid Howells current->pid, current->comm, 143433e5d769SDavid Howells start, start + len - 1); 143533e5d769SDavid Howells limit++; 143633e5d769SDavid Howells } 14378feae131SDavid Howells return -EINVAL; 14388feae131SDavid Howells } 14391da177e4SLinus Torvalds 14408feae131SDavid Howells /* we're allowed to split an anonymous VMA but not a file-backed one */ 14418feae131SDavid Howells if (vma->vm_file) { 14428feae131SDavid Howells do { 144322cc877bSLeon Romanovsky if (start > vma->vm_start) 14448feae131SDavid Howells return -EINVAL; 14458feae131SDavid Howells if (end == vma->vm_end) 14468feae131SDavid Howells goto erase_whole_vma; 1447d75a310cSNamhyung Kim vma = vma->vm_next; 1448d75a310cSNamhyung Kim } while (vma); 14498feae131SDavid Howells return -EINVAL; 14508feae131SDavid Howells } else { 14518feae131SDavid Howells /* the chunk must be a subset of the VMA found */ 14528feae131SDavid Howells if (start == vma->vm_start && end == vma->vm_end) 14538feae131SDavid Howells goto erase_whole_vma; 145422cc877bSLeon Romanovsky if (start < vma->vm_start || end > vma->vm_end) 14558feae131SDavid Howells return -EINVAL; 14561824cb75SAlexander Kuleshov if (offset_in_page(start)) 14578feae131SDavid Howells return -EINVAL; 14581824cb75SAlexander Kuleshov if (end != vma->vm_end && offset_in_page(end)) 14598feae131SDavid Howells return -EINVAL; 14608feae131SDavid Howells if (start != vma->vm_start && end != vma->vm_end) { 14618feae131SDavid Howells ret = split_vma(mm, vma, start, 1); 146222cc877bSLeon Romanovsky if (ret < 0) 14638feae131SDavid Howells return ret; 14648feae131SDavid Howells } 14658feae131SDavid Howells return shrink_vma(mm, vma, start, end); 14668feae131SDavid Howells } 14671da177e4SLinus Torvalds 14688feae131SDavid Howells erase_whole_vma: 14698feae131SDavid Howells delete_vma_from_mm(vma); 14708feae131SDavid Howells delete_vma(mm, vma); 14711da177e4SLinus Torvalds return 0; 14721da177e4SLinus Torvalds } 14731da177e4SLinus Torvalds 1474bfce281cSAl Viro int vm_munmap(unsigned long addr, size_t len) 14753034097aSDavid Howells { 1476bfce281cSAl Viro struct mm_struct *mm = current->mm; 14773034097aSDavid Howells int ret; 14783034097aSDavid Howells 1479d8ed45c5SMichel Lespinasse mmap_write_lock(mm); 1480897ab3e0SMike Rapoport ret = do_munmap(mm, addr, len, NULL); 1481d8ed45c5SMichel Lespinasse mmap_write_unlock(mm); 14823034097aSDavid Howells return ret; 14833034097aSDavid Howells } 1484a46ef99dSLinus Torvalds EXPORT_SYMBOL(vm_munmap); 1485a46ef99dSLinus Torvalds 1486a46ef99dSLinus Torvalds SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) 1487a46ef99dSLinus Torvalds { 1488bfce281cSAl Viro return vm_munmap(addr, len); 1489a46ef99dSLinus Torvalds } 14903034097aSDavid Howells 14913034097aSDavid Howells /* 14928feae131SDavid Howells * release all the mappings made in a process's VM space 14933034097aSDavid Howells */ 14941da177e4SLinus Torvalds void exit_mmap(struct mm_struct *mm) 14951da177e4SLinus Torvalds { 14968feae131SDavid Howells struct vm_area_struct *vma; 14971da177e4SLinus Torvalds 14988feae131SDavid Howells if (!mm) 14998feae131SDavid Howells return; 15008feae131SDavid Howells 15011da177e4SLinus Torvalds mm->total_vm = 0; 15021da177e4SLinus Torvalds 15038feae131SDavid Howells while ((vma = mm->mmap)) { 15048feae131SDavid Howells mm->mmap = vma->vm_next; 15058feae131SDavid Howells delete_vma_from_mm(vma); 15068feae131SDavid Howells delete_vma(mm, vma); 150704c34961SSteven J. Magnani cond_resched(); 15081da177e4SLinus Torvalds } 1509*524e00b3SLiam R. Howlett __mt_destroy(&mm->mm_mt); 15101da177e4SLinus Torvalds } 15111da177e4SLinus Torvalds 15125d22fc25SLinus Torvalds int vm_brk(unsigned long addr, unsigned long len) 15131da177e4SLinus Torvalds { 15141da177e4SLinus Torvalds return -ENOMEM; 15151da177e4SLinus Torvalds } 15161da177e4SLinus Torvalds 15171da177e4SLinus Torvalds /* 15186fa5f80bSDavid Howells * expand (or shrink) an existing mapping, potentially moving it at the same 15196fa5f80bSDavid Howells * time (controlled by the MREMAP_MAYMOVE flag and available VM space) 15201da177e4SLinus Torvalds * 15216fa5f80bSDavid Howells * under NOMMU conditions, we only permit changing a mapping's size, and only 15228feae131SDavid Howells * as long as it stays within the region allocated by do_mmap_private() and the 15238feae131SDavid Howells * block is not shareable 15241da177e4SLinus Torvalds * 15256fa5f80bSDavid Howells * MREMAP_FIXED is not supported under NOMMU conditions 15261da177e4SLinus Torvalds */ 15274b377babSAl Viro static unsigned long do_mremap(unsigned long addr, 15281da177e4SLinus Torvalds unsigned long old_len, unsigned long new_len, 15291da177e4SLinus Torvalds unsigned long flags, unsigned long new_addr) 15301da177e4SLinus Torvalds { 15316fa5f80bSDavid Howells struct vm_area_struct *vma; 15321da177e4SLinus Torvalds 15331da177e4SLinus Torvalds /* insanity checks first */ 1534f67d9b15SBob Liu old_len = PAGE_ALIGN(old_len); 1535f67d9b15SBob Liu new_len = PAGE_ALIGN(new_len); 15368feae131SDavid Howells if (old_len == 0 || new_len == 0) 15371da177e4SLinus Torvalds return (unsigned long) -EINVAL; 15381da177e4SLinus Torvalds 15391824cb75SAlexander Kuleshov if (offset_in_page(addr)) 15408feae131SDavid Howells return -EINVAL; 15418feae131SDavid Howells 15421da177e4SLinus Torvalds if (flags & MREMAP_FIXED && new_addr != addr) 15431da177e4SLinus Torvalds return (unsigned long) -EINVAL; 15441da177e4SLinus Torvalds 15458feae131SDavid Howells vma = find_vma_exact(current->mm, addr, old_len); 15466fa5f80bSDavid Howells if (!vma) 15471da177e4SLinus Torvalds return (unsigned long) -EINVAL; 15481da177e4SLinus Torvalds 15496fa5f80bSDavid Howells if (vma->vm_end != vma->vm_start + old_len) 15501da177e4SLinus Torvalds return (unsigned long) -EFAULT; 15511da177e4SLinus Torvalds 15526fa5f80bSDavid Howells if (vma->vm_flags & VM_MAYSHARE) 15531da177e4SLinus Torvalds return (unsigned long) -EPERM; 15541da177e4SLinus Torvalds 15558feae131SDavid Howells if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) 15561da177e4SLinus Torvalds return (unsigned long) -ENOMEM; 15571da177e4SLinus Torvalds 15581da177e4SLinus Torvalds /* all checks complete - do it */ 15596fa5f80bSDavid Howells vma->vm_end = vma->vm_start + new_len; 15606fa5f80bSDavid Howells return vma->vm_start; 15616fa5f80bSDavid Howells } 15626fa5f80bSDavid Howells 15636a6160a7SHeiko Carstens SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 15646a6160a7SHeiko Carstens unsigned long, new_len, unsigned long, flags, 15656a6160a7SHeiko Carstens unsigned long, new_addr) 15666fa5f80bSDavid Howells { 15676fa5f80bSDavid Howells unsigned long ret; 15686fa5f80bSDavid Howells 1569d8ed45c5SMichel Lespinasse mmap_write_lock(current->mm); 15706fa5f80bSDavid Howells ret = do_mremap(addr, old_len, new_len, flags, new_addr); 1571d8ed45c5SMichel Lespinasse mmap_write_unlock(current->mm); 15726fa5f80bSDavid Howells return ret; 15731da177e4SLinus Torvalds } 15741da177e4SLinus Torvalds 1575df06b37fSKeith Busch struct page *follow_page(struct vm_area_struct *vma, unsigned long address, 1576df06b37fSKeith Busch unsigned int foll_flags) 15771da177e4SLinus Torvalds { 15781da177e4SLinus Torvalds return NULL; 15791da177e4SLinus Torvalds } 15801da177e4SLinus Torvalds 15818f3b1327SBob Liu int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 15828f3b1327SBob Liu unsigned long pfn, unsigned long size, pgprot_t prot) 15831da177e4SLinus Torvalds { 15848f3b1327SBob Liu if (addr != (pfn << PAGE_SHIFT)) 15858f3b1327SBob Liu return -EINVAL; 15868f3b1327SBob Liu 1587314e51b9SKonstantin Khlebnikov vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 158866aa2b4bSGreg Ungerer return 0; 15891da177e4SLinus Torvalds } 159022c4af40SLuke Yang EXPORT_SYMBOL(remap_pfn_range); 15911da177e4SLinus Torvalds 15923c0b9de6SLinus Torvalds int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) 15933c0b9de6SLinus Torvalds { 15943c0b9de6SLinus Torvalds unsigned long pfn = start >> PAGE_SHIFT; 15953c0b9de6SLinus Torvalds unsigned long vm_len = vma->vm_end - vma->vm_start; 15963c0b9de6SLinus Torvalds 15973c0b9de6SLinus Torvalds pfn += vma->vm_pgoff; 15983c0b9de6SLinus Torvalds return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); 15993c0b9de6SLinus Torvalds } 16003c0b9de6SLinus Torvalds EXPORT_SYMBOL(vm_iomap_memory); 16013c0b9de6SLinus Torvalds 1602f905bc44SPaul Mundt int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 1603f905bc44SPaul Mundt unsigned long pgoff) 1604f905bc44SPaul Mundt { 1605f905bc44SPaul Mundt unsigned int size = vma->vm_end - vma->vm_start; 1606f905bc44SPaul Mundt 1607f905bc44SPaul Mundt if (!(vma->vm_flags & VM_USERMAP)) 1608f905bc44SPaul Mundt return -EINVAL; 1609f905bc44SPaul Mundt 1610f905bc44SPaul Mundt vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); 1611f905bc44SPaul Mundt vma->vm_end = vma->vm_start + size; 1612f905bc44SPaul Mundt 1613f905bc44SPaul Mundt return 0; 1614f905bc44SPaul Mundt } 1615f905bc44SPaul Mundt EXPORT_SYMBOL(remap_vmalloc_range); 1616f905bc44SPaul Mundt 16172bcd6454SSouptick Joarder vm_fault_t filemap_fault(struct vm_fault *vmf) 1618b0e15190SDavid Howells { 1619b0e15190SDavid Howells BUG(); 1620d0217ac0SNick Piggin return 0; 1621b0e15190SDavid Howells } 1622b5073173SPaul Mundt EXPORT_SYMBOL(filemap_fault); 16230ec76a11SDavid Howells 16243f98a28cSGeert Uytterhoeven vm_fault_t filemap_map_pages(struct vm_fault *vmf, 1625bae473a4SKirill A. Shutemov pgoff_t start_pgoff, pgoff_t end_pgoff) 1626f1820361SKirill A. Shutemov { 1627f1820361SKirill A. Shutemov BUG(); 16283f98a28cSGeert Uytterhoeven return 0; 1629f1820361SKirill A. Shutemov } 1630f1820361SKirill A. Shutemov EXPORT_SYMBOL(filemap_map_pages); 1631f1820361SKirill A. Shutemov 1632d3f5ffcaSJohn Hubbard int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf, 1633d3f5ffcaSJohn Hubbard int len, unsigned int gup_flags) 16340ec76a11SDavid Howells { 16350ec76a11SDavid Howells struct vm_area_struct *vma; 1636442486ecSLorenzo Stoakes int write = gup_flags & FOLL_WRITE; 16370ec76a11SDavid Howells 1638d8ed45c5SMichel Lespinasse if (mmap_read_lock_killable(mm)) 16391e426fe2SKonstantin Khlebnikov return 0; 16400ec76a11SDavid Howells 16410ec76a11SDavid Howells /* the access must start within one of the target process's mappings */ 16420159b141SDavid Howells vma = find_vma(mm, addr); 16430159b141SDavid Howells if (vma) { 16440ec76a11SDavid Howells /* don't overrun this mapping */ 16450ec76a11SDavid Howells if (addr + len >= vma->vm_end) 16460ec76a11SDavid Howells len = vma->vm_end - addr; 16470ec76a11SDavid Howells 16480ec76a11SDavid Howells /* only read or write mappings where it is permitted */ 1649d00c7b99SDavid Howells if (write && vma->vm_flags & VM_MAYWRITE) 16507959722bSJie Zhang copy_to_user_page(vma, NULL, addr, 16517959722bSJie Zhang (void *) addr, buf, len); 1652d00c7b99SDavid Howells else if (!write && vma->vm_flags & VM_MAYREAD) 16537959722bSJie Zhang copy_from_user_page(vma, NULL, addr, 16547959722bSJie Zhang buf, (void *) addr, len); 16550ec76a11SDavid Howells else 16560ec76a11SDavid Howells len = 0; 16570ec76a11SDavid Howells } else { 16580ec76a11SDavid Howells len = 0; 16590ec76a11SDavid Howells } 16600ec76a11SDavid Howells 1661d8ed45c5SMichel Lespinasse mmap_read_unlock(mm); 1662f55f199bSMike Frysinger 1663f55f199bSMike Frysinger return len; 1664f55f199bSMike Frysinger } 1665f55f199bSMike Frysinger 1666f55f199bSMike Frysinger /** 1667b7701a5fSMike Rapoport * access_remote_vm - access another process' address space 1668f55f199bSMike Frysinger * @mm: the mm_struct of the target address space 1669f55f199bSMike Frysinger * @addr: start address to access 1670f55f199bSMike Frysinger * @buf: source or destination buffer 1671f55f199bSMike Frysinger * @len: number of bytes to transfer 16726347e8d5SLorenzo Stoakes * @gup_flags: flags modifying lookup behaviour 1673f55f199bSMike Frysinger * 1674f55f199bSMike Frysinger * The caller must hold a reference on @mm. 1675f55f199bSMike Frysinger */ 1676f55f199bSMike Frysinger int access_remote_vm(struct mm_struct *mm, unsigned long addr, 16776347e8d5SLorenzo Stoakes void *buf, int len, unsigned int gup_flags) 1678f55f199bSMike Frysinger { 1679d3f5ffcaSJohn Hubbard return __access_remote_vm(mm, addr, buf, len, gup_flags); 1680f55f199bSMike Frysinger } 1681f55f199bSMike Frysinger 1682f55f199bSMike Frysinger /* 1683f55f199bSMike Frysinger * Access another process' address space. 1684f55f199bSMike Frysinger * - source/target buffer must be kernel space 1685f55f199bSMike Frysinger */ 1686f307ab6dSLorenzo Stoakes int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, 1687f307ab6dSLorenzo Stoakes unsigned int gup_flags) 1688f55f199bSMike Frysinger { 1689f55f199bSMike Frysinger struct mm_struct *mm; 1690f55f199bSMike Frysinger 1691f55f199bSMike Frysinger if (addr + len < addr) 1692f55f199bSMike Frysinger return 0; 1693f55f199bSMike Frysinger 1694f55f199bSMike Frysinger mm = get_task_mm(tsk); 1695f55f199bSMike Frysinger if (!mm) 1696f55f199bSMike Frysinger return 0; 1697f55f199bSMike Frysinger 1698d3f5ffcaSJohn Hubbard len = __access_remote_vm(mm, addr, buf, len, gup_flags); 1699f55f199bSMike Frysinger 17000ec76a11SDavid Howells mmput(mm); 17010ec76a11SDavid Howells return len; 17020ec76a11SDavid Howells } 1703fcd35857SCatalin Marinas EXPORT_SYMBOL_GPL(access_process_vm); 17047e660872SDavid Howells 17057e660872SDavid Howells /** 17067e660872SDavid Howells * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode 17077e660872SDavid Howells * @inode: The inode to check 17087e660872SDavid Howells * @size: The current filesize of the inode 17097e660872SDavid Howells * @newsize: The proposed filesize of the inode 17107e660872SDavid Howells * 17117e660872SDavid Howells * Check the shared mappings on an inode on behalf of a shrinking truncate to 1712c08b342cSRandy Dunlap * make sure that any outstanding VMAs aren't broken and then shrink the 1713c08b342cSRandy Dunlap * vm_regions that extend beyond so that do_mmap() doesn't 17147e660872SDavid Howells * automatically grant mappings that are too large. 17157e660872SDavid Howells */ 17167e660872SDavid Howells int nommu_shrink_inode_mappings(struct inode *inode, size_t size, 17177e660872SDavid Howells size_t newsize) 17187e660872SDavid Howells { 17197e660872SDavid Howells struct vm_area_struct *vma; 17207e660872SDavid Howells struct vm_region *region; 17217e660872SDavid Howells pgoff_t low, high; 17227e660872SDavid Howells size_t r_size, r_top; 17237e660872SDavid Howells 17247e660872SDavid Howells low = newsize >> PAGE_SHIFT; 17257e660872SDavid Howells high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 17267e660872SDavid Howells 17277e660872SDavid Howells down_write(&nommu_region_sem); 17281acf2e04SDavidlohr Bueso i_mmap_lock_read(inode->i_mapping); 17297e660872SDavid Howells 17307e660872SDavid Howells /* search for VMAs that fall within the dead zone */ 17316b2dbba8SMichel Lespinasse vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) { 17327e660872SDavid Howells /* found one - only interested if it's shared out of the page 17337e660872SDavid Howells * cache */ 17347e660872SDavid Howells if (vma->vm_flags & VM_SHARED) { 17351acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 17367e660872SDavid Howells up_write(&nommu_region_sem); 17377e660872SDavid Howells return -ETXTBSY; /* not quite true, but near enough */ 17387e660872SDavid Howells } 17397e660872SDavid Howells } 17407e660872SDavid Howells 17417e660872SDavid Howells /* reduce any regions that overlap the dead zone - if in existence, 17427e660872SDavid Howells * these will be pointed to by VMAs that don't overlap the dead zone 17437e660872SDavid Howells * 17447e660872SDavid Howells * we don't check for any regions that start beyond the EOF as there 17457e660872SDavid Howells * shouldn't be any 17467e660872SDavid Howells */ 17471acf2e04SDavidlohr Bueso vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 0, ULONG_MAX) { 17487e660872SDavid Howells if (!(vma->vm_flags & VM_SHARED)) 17497e660872SDavid Howells continue; 17507e660872SDavid Howells 17517e660872SDavid Howells region = vma->vm_region; 17527e660872SDavid Howells r_size = region->vm_top - region->vm_start; 17537e660872SDavid Howells r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; 17547e660872SDavid Howells 17557e660872SDavid Howells if (r_top > newsize) { 17567e660872SDavid Howells region->vm_top -= r_top - newsize; 17577e660872SDavid Howells if (region->vm_end > region->vm_top) 17587e660872SDavid Howells region->vm_end = region->vm_top; 17597e660872SDavid Howells } 17607e660872SDavid Howells } 17617e660872SDavid Howells 17621acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 17637e660872SDavid Howells up_write(&nommu_region_sem); 17647e660872SDavid Howells return 0; 17657e660872SDavid Howells } 1766c9b1d098SAndrew Shewmaker 1767c9b1d098SAndrew Shewmaker /* 1768c9b1d098SAndrew Shewmaker * Initialise sysctl_user_reserve_kbytes. 1769c9b1d098SAndrew Shewmaker * 1770c9b1d098SAndrew Shewmaker * This is intended to prevent a user from starting a single memory hogging 1771c9b1d098SAndrew Shewmaker * process, such that they cannot recover (kill the hog) in OVERCOMMIT_NEVER 1772c9b1d098SAndrew Shewmaker * mode. 1773c9b1d098SAndrew Shewmaker * 1774c9b1d098SAndrew Shewmaker * The default value is min(3% of free memory, 128MB) 1775c9b1d098SAndrew Shewmaker * 128MB is enough to recover with sshd/login, bash, and top/kill. 1776c9b1d098SAndrew Shewmaker */ 1777c9b1d098SAndrew Shewmaker static int __meminit init_user_reserve(void) 1778c9b1d098SAndrew Shewmaker { 1779c9b1d098SAndrew Shewmaker unsigned long free_kbytes; 1780c9b1d098SAndrew Shewmaker 1781c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 1782c9b1d098SAndrew Shewmaker 1783c9b1d098SAndrew Shewmaker sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17); 1784c9b1d098SAndrew Shewmaker return 0; 1785c9b1d098SAndrew Shewmaker } 1786a4bc6fc7SPaul Gortmaker subsys_initcall(init_user_reserve); 17874eeab4f5SAndrew Shewmaker 17884eeab4f5SAndrew Shewmaker /* 17894eeab4f5SAndrew Shewmaker * Initialise sysctl_admin_reserve_kbytes. 17904eeab4f5SAndrew Shewmaker * 17914eeab4f5SAndrew Shewmaker * The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin 17924eeab4f5SAndrew Shewmaker * to log in and kill a memory hogging process. 17934eeab4f5SAndrew Shewmaker * 17944eeab4f5SAndrew Shewmaker * Systems with more than 256MB will reserve 8MB, enough to recover 17954eeab4f5SAndrew Shewmaker * with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will 17964eeab4f5SAndrew Shewmaker * only reserve 3% of free pages by default. 17974eeab4f5SAndrew Shewmaker */ 17984eeab4f5SAndrew Shewmaker static int __meminit init_admin_reserve(void) 17994eeab4f5SAndrew Shewmaker { 18004eeab4f5SAndrew Shewmaker unsigned long free_kbytes; 18014eeab4f5SAndrew Shewmaker 1802c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 18034eeab4f5SAndrew Shewmaker 18044eeab4f5SAndrew Shewmaker sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13); 18054eeab4f5SAndrew Shewmaker return 0; 18064eeab4f5SAndrew Shewmaker } 1807a4bc6fc7SPaul Gortmaker subsys_initcall(init_admin_reserve); 1808