11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/mm/nommu.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Replacement code for mm functions to support CPU's that don't 51da177e4SLinus Torvalds * have any form of memory management unit (thus no virtual memory). 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * See Documentation/nommu-mmap.txt 81da177e4SLinus Torvalds * 98feae131SDavid Howells * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com> 101da177e4SLinus Torvalds * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> 111da177e4SLinus Torvalds * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> 121da177e4SLinus Torvalds * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> 1329c185e5SPaul Mundt * Copyright (c) 2007-2010 Paul Mundt <lethal@linux-sh.org> 141da177e4SLinus Torvalds */ 151da177e4SLinus Torvalds 16b95f1b31SPaul Gortmaker #include <linux/export.h> 171da177e4SLinus Torvalds #include <linux/mm.h> 181da177e4SLinus Torvalds #include <linux/mman.h> 191da177e4SLinus Torvalds #include <linux/swap.h> 201da177e4SLinus Torvalds #include <linux/file.h> 211da177e4SLinus Torvalds #include <linux/highmem.h> 221da177e4SLinus Torvalds #include <linux/pagemap.h> 231da177e4SLinus Torvalds #include <linux/slab.h> 241da177e4SLinus Torvalds #include <linux/vmalloc.h> 251da177e4SLinus Torvalds #include <linux/blkdev.h> 261da177e4SLinus Torvalds #include <linux/backing-dev.h> 271da177e4SLinus Torvalds #include <linux/mount.h> 281da177e4SLinus Torvalds #include <linux/personality.h> 291da177e4SLinus Torvalds #include <linux/security.h> 301da177e4SLinus Torvalds #include <linux/syscalls.h> 31120a795dSAl Viro #include <linux/audit.h> 321da177e4SLinus Torvalds 331da177e4SLinus Torvalds #include <asm/uaccess.h> 341da177e4SLinus Torvalds #include <asm/tlb.h> 351da177e4SLinus Torvalds #include <asm/tlbflush.h> 36eb8cdec4SBernd Schmidt #include <asm/mmu_context.h> 378feae131SDavid Howells #include "internal.h" 388feae131SDavid Howells 398feae131SDavid Howells #if 0 408feae131SDavid Howells #define kenter(FMT, ...) \ 418feae131SDavid Howells printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) 428feae131SDavid Howells #define kleave(FMT, ...) \ 438feae131SDavid Howells printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) 448feae131SDavid Howells #define kdebug(FMT, ...) \ 458feae131SDavid Howells printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__) 468feae131SDavid Howells #else 478feae131SDavid Howells #define kenter(FMT, ...) \ 488feae131SDavid Howells no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) 498feae131SDavid Howells #define kleave(FMT, ...) \ 508feae131SDavid Howells no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) 518feae131SDavid Howells #define kdebug(FMT, ...) \ 528feae131SDavid Howells no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) 538feae131SDavid Howells #endif 541da177e4SLinus Torvalds 551da177e4SLinus Torvalds void *high_memory; 561da177e4SLinus Torvalds struct page *mem_map; 571da177e4SLinus Torvalds unsigned long max_mapnr; 581da177e4SLinus Torvalds unsigned long num_physpages; 594266c97aSHugh Dickins unsigned long highest_memmap_pfn; 6000a62ce9SKOSAKI Motohiro struct percpu_counter vm_committed_as; 611da177e4SLinus Torvalds int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ 621da177e4SLinus Torvalds int sysctl_overcommit_ratio = 50; /* default is 50% */ 631da177e4SLinus Torvalds int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; 64fc4d5c29SDavid Howells int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; 651da177e4SLinus Torvalds int heap_stack_gap = 0; 661da177e4SLinus Torvalds 6733e5d769SDavid Howells atomic_long_t mmap_pages_allocated; 688feae131SDavid Howells 69997071bcSK. Y. Srinivasan /* 70997071bcSK. Y. Srinivasan * The global memory commitment made in the system can be a metric 71997071bcSK. Y. Srinivasan * that can be used to drive ballooning decisions when Linux is hosted 72997071bcSK. Y. Srinivasan * as a guest. On Hyper-V, the host implements a policy engine for dynamically 73997071bcSK. Y. Srinivasan * balancing memory across competing virtual machines that are hosted. 74997071bcSK. Y. Srinivasan * Several metrics drive this policy engine including the guest reported 75997071bcSK. Y. Srinivasan * memory commitment. 76997071bcSK. Y. Srinivasan */ 77997071bcSK. Y. Srinivasan unsigned long vm_memory_committed(void) 78997071bcSK. Y. Srinivasan { 79997071bcSK. Y. Srinivasan return percpu_counter_read_positive(&vm_committed_as); 80997071bcSK. Y. Srinivasan } 81997071bcSK. Y. Srinivasan 82997071bcSK. Y. Srinivasan EXPORT_SYMBOL_GPL(vm_memory_committed); 83997071bcSK. Y. Srinivasan 841da177e4SLinus Torvalds EXPORT_SYMBOL(mem_map); 856a04de6dSWu, Bryan EXPORT_SYMBOL(num_physpages); 861da177e4SLinus Torvalds 878feae131SDavid Howells /* list of mapped, potentially shareable regions */ 888feae131SDavid Howells static struct kmem_cache *vm_region_jar; 898feae131SDavid Howells struct rb_root nommu_region_tree = RB_ROOT; 908feae131SDavid Howells DECLARE_RWSEM(nommu_region_sem); 911da177e4SLinus Torvalds 92f0f37e2fSAlexey Dobriyan const struct vm_operations_struct generic_file_vm_ops = { 931da177e4SLinus Torvalds }; 941da177e4SLinus Torvalds 951da177e4SLinus Torvalds /* 961da177e4SLinus Torvalds * Return the total memory allocated for this pointer, not 971da177e4SLinus Torvalds * just what the caller asked for. 981da177e4SLinus Torvalds * 991da177e4SLinus Torvalds * Doesn't have to be accurate, i.e. may have races. 1001da177e4SLinus Torvalds */ 1011da177e4SLinus Torvalds unsigned int kobjsize(const void *objp) 1021da177e4SLinus Torvalds { 1031da177e4SLinus Torvalds struct page *page; 1041da177e4SLinus Torvalds 1054016a139SMichael Hennerich /* 1064016a139SMichael Hennerich * If the object we have should not have ksize performed on it, 1074016a139SMichael Hennerich * return size of 0 1084016a139SMichael Hennerich */ 1095a1603beSPaul Mundt if (!objp || !virt_addr_valid(objp)) 1106cfd53fcSPaul Mundt return 0; 1116cfd53fcSPaul Mundt 1126cfd53fcSPaul Mundt page = virt_to_head_page(objp); 1136cfd53fcSPaul Mundt 1146cfd53fcSPaul Mundt /* 1156cfd53fcSPaul Mundt * If the allocator sets PageSlab, we know the pointer came from 1166cfd53fcSPaul Mundt * kmalloc(). 1176cfd53fcSPaul Mundt */ 1181da177e4SLinus Torvalds if (PageSlab(page)) 1191da177e4SLinus Torvalds return ksize(objp); 1201da177e4SLinus Torvalds 1216cfd53fcSPaul Mundt /* 122ab2e83eaSPaul Mundt * If it's not a compound page, see if we have a matching VMA 123ab2e83eaSPaul Mundt * region. This test is intentionally done in reverse order, 124ab2e83eaSPaul Mundt * so if there's no VMA, we still fall through and hand back 125ab2e83eaSPaul Mundt * PAGE_SIZE for 0-order pages. 126ab2e83eaSPaul Mundt */ 127ab2e83eaSPaul Mundt if (!PageCompound(page)) { 128ab2e83eaSPaul Mundt struct vm_area_struct *vma; 129ab2e83eaSPaul Mundt 130ab2e83eaSPaul Mundt vma = find_vma(current->mm, (unsigned long)objp); 131ab2e83eaSPaul Mundt if (vma) 132ab2e83eaSPaul Mundt return vma->vm_end - vma->vm_start; 133ab2e83eaSPaul Mundt } 134ab2e83eaSPaul Mundt 135ab2e83eaSPaul Mundt /* 1366cfd53fcSPaul Mundt * The ksize() function is only guaranteed to work for pointers 1375a1603beSPaul Mundt * returned by kmalloc(). So handle arbitrary pointers here. 1386cfd53fcSPaul Mundt */ 1395a1603beSPaul Mundt return PAGE_SIZE << compound_order(page); 1401da177e4SLinus Torvalds } 1411da177e4SLinus Torvalds 142b291f000SNick Piggin int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 1434266c97aSHugh Dickins unsigned long start, int nr_pages, unsigned int foll_flags, 14453a7706dSMichel Lespinasse struct page **pages, struct vm_area_struct **vmas, 14553a7706dSMichel Lespinasse int *retry) 1461da177e4SLinus Torvalds { 147910e46daSSonic Zhang struct vm_area_struct *vma; 1487b4d5b8bSDavid Howells unsigned long vm_flags; 1497b4d5b8bSDavid Howells int i; 1507b4d5b8bSDavid Howells 1517b4d5b8bSDavid Howells /* calculate required read or write permissions. 15258fa879eSHugh Dickins * If FOLL_FORCE is set, we only require the "MAY" flags. 1537b4d5b8bSDavid Howells */ 15458fa879eSHugh Dickins vm_flags = (foll_flags & FOLL_WRITE) ? 15558fa879eSHugh Dickins (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); 15658fa879eSHugh Dickins vm_flags &= (foll_flags & FOLL_FORCE) ? 15758fa879eSHugh Dickins (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); 1581da177e4SLinus Torvalds 1599d73777eSPeter Zijlstra for (i = 0; i < nr_pages; i++) { 1607561e8caSDavid Howells vma = find_vma(mm, start); 161910e46daSSonic Zhang if (!vma) 1627b4d5b8bSDavid Howells goto finish_or_fault; 1637b4d5b8bSDavid Howells 1647b4d5b8bSDavid Howells /* protect what we can, including chardevs */ 1651c3aff1cSHugh Dickins if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) || 1661c3aff1cSHugh Dickins !(vm_flags & vma->vm_flags)) 1677b4d5b8bSDavid Howells goto finish_or_fault; 168910e46daSSonic Zhang 1691da177e4SLinus Torvalds if (pages) { 1701da177e4SLinus Torvalds pages[i] = virt_to_page(start); 1711da177e4SLinus Torvalds if (pages[i]) 1721da177e4SLinus Torvalds page_cache_get(pages[i]); 1731da177e4SLinus Torvalds } 1741da177e4SLinus Torvalds if (vmas) 175910e46daSSonic Zhang vmas[i] = vma; 176e1ee65d8SDavid Howells start = (start + PAGE_SIZE) & PAGE_MASK; 1771da177e4SLinus Torvalds } 1787b4d5b8bSDavid Howells 1797b4d5b8bSDavid Howells return i; 1807b4d5b8bSDavid Howells 1817b4d5b8bSDavid Howells finish_or_fault: 1827b4d5b8bSDavid Howells return i ? : -EFAULT; 1831da177e4SLinus Torvalds } 184b291f000SNick Piggin 185b291f000SNick Piggin /* 186b291f000SNick Piggin * get a list of pages in an address range belonging to the specified process 187b291f000SNick Piggin * and indicate the VMA that covers each page 188b291f000SNick Piggin * - this is potentially dodgy as we may end incrementing the page count of a 189b291f000SNick Piggin * slab page or a secondary page from a compound page 190b291f000SNick Piggin * - don't permit access to VMAs that don't support it, such as I/O mappings 191b291f000SNick Piggin */ 192b291f000SNick Piggin int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 1939d73777eSPeter Zijlstra unsigned long start, int nr_pages, int write, int force, 194b291f000SNick Piggin struct page **pages, struct vm_area_struct **vmas) 195b291f000SNick Piggin { 196b291f000SNick Piggin int flags = 0; 197b291f000SNick Piggin 198b291f000SNick Piggin if (write) 19958fa879eSHugh Dickins flags |= FOLL_WRITE; 200b291f000SNick Piggin if (force) 20158fa879eSHugh Dickins flags |= FOLL_FORCE; 202b291f000SNick Piggin 20353a7706dSMichel Lespinasse return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas, 20453a7706dSMichel Lespinasse NULL); 205b291f000SNick Piggin } 20666aa2b4bSGreg Ungerer EXPORT_SYMBOL(get_user_pages); 20766aa2b4bSGreg Ungerer 208dfc2f91aSPaul Mundt /** 209dfc2f91aSPaul Mundt * follow_pfn - look up PFN at a user virtual address 210dfc2f91aSPaul Mundt * @vma: memory mapping 211dfc2f91aSPaul Mundt * @address: user virtual address 212dfc2f91aSPaul Mundt * @pfn: location to store found PFN 213dfc2f91aSPaul Mundt * 214dfc2f91aSPaul Mundt * Only IO mappings and raw PFN mappings are allowed. 215dfc2f91aSPaul Mundt * 216dfc2f91aSPaul Mundt * Returns zero and the pfn at @pfn on success, -ve otherwise. 217dfc2f91aSPaul Mundt */ 218dfc2f91aSPaul Mundt int follow_pfn(struct vm_area_struct *vma, unsigned long address, 219dfc2f91aSPaul Mundt unsigned long *pfn) 220dfc2f91aSPaul Mundt { 221dfc2f91aSPaul Mundt if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 222dfc2f91aSPaul Mundt return -EINVAL; 223dfc2f91aSPaul Mundt 224dfc2f91aSPaul Mundt *pfn = address >> PAGE_SHIFT; 225dfc2f91aSPaul Mundt return 0; 226dfc2f91aSPaul Mundt } 227dfc2f91aSPaul Mundt EXPORT_SYMBOL(follow_pfn); 228dfc2f91aSPaul Mundt 2291da177e4SLinus Torvalds DEFINE_RWLOCK(vmlist_lock); 2301da177e4SLinus Torvalds struct vm_struct *vmlist; 2311da177e4SLinus Torvalds 232b3bdda02SChristoph Lameter void vfree(const void *addr) 2331da177e4SLinus Torvalds { 2341da177e4SLinus Torvalds kfree(addr); 2351da177e4SLinus Torvalds } 236b5073173SPaul Mundt EXPORT_SYMBOL(vfree); 2371da177e4SLinus Torvalds 238dd0fc66fSAl Viro void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) 2391da177e4SLinus Torvalds { 2401da177e4SLinus Torvalds /* 2418518609dSRobert P. J. Day * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() 2428518609dSRobert P. J. Day * returns only a logical address. 2431da177e4SLinus Torvalds */ 24484097518SNick Piggin return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); 2451da177e4SLinus Torvalds } 246b5073173SPaul Mundt EXPORT_SYMBOL(__vmalloc); 2471da177e4SLinus Torvalds 248f905bc44SPaul Mundt void *vmalloc_user(unsigned long size) 249f905bc44SPaul Mundt { 250f905bc44SPaul Mundt void *ret; 251f905bc44SPaul Mundt 252f905bc44SPaul Mundt ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, 253f905bc44SPaul Mundt PAGE_KERNEL); 254f905bc44SPaul Mundt if (ret) { 255f905bc44SPaul Mundt struct vm_area_struct *vma; 256f905bc44SPaul Mundt 257f905bc44SPaul Mundt down_write(¤t->mm->mmap_sem); 258f905bc44SPaul Mundt vma = find_vma(current->mm, (unsigned long)ret); 259f905bc44SPaul Mundt if (vma) 260f905bc44SPaul Mundt vma->vm_flags |= VM_USERMAP; 261f905bc44SPaul Mundt up_write(¤t->mm->mmap_sem); 262f905bc44SPaul Mundt } 263f905bc44SPaul Mundt 264f905bc44SPaul Mundt return ret; 265f905bc44SPaul Mundt } 266f905bc44SPaul Mundt EXPORT_SYMBOL(vmalloc_user); 267f905bc44SPaul Mundt 268b3bdda02SChristoph Lameter struct page *vmalloc_to_page(const void *addr) 2691da177e4SLinus Torvalds { 2701da177e4SLinus Torvalds return virt_to_page(addr); 2711da177e4SLinus Torvalds } 272b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_page); 2731da177e4SLinus Torvalds 274b3bdda02SChristoph Lameter unsigned long vmalloc_to_pfn(const void *addr) 2751da177e4SLinus Torvalds { 2761da177e4SLinus Torvalds return page_to_pfn(virt_to_page(addr)); 2771da177e4SLinus Torvalds } 278b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_pfn); 2791da177e4SLinus Torvalds 2801da177e4SLinus Torvalds long vread(char *buf, char *addr, unsigned long count) 2811da177e4SLinus Torvalds { 2821da177e4SLinus Torvalds memcpy(buf, addr, count); 2831da177e4SLinus Torvalds return count; 2841da177e4SLinus Torvalds } 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds long vwrite(char *buf, char *addr, unsigned long count) 2871da177e4SLinus Torvalds { 2881da177e4SLinus Torvalds /* Don't allow overflow */ 2891da177e4SLinus Torvalds if ((unsigned long) addr + count < count) 2901da177e4SLinus Torvalds count = -(unsigned long) addr; 2911da177e4SLinus Torvalds 2921da177e4SLinus Torvalds memcpy(addr, buf, count); 2931da177e4SLinus Torvalds return(count); 2941da177e4SLinus Torvalds } 2951da177e4SLinus Torvalds 2961da177e4SLinus Torvalds /* 2971da177e4SLinus Torvalds * vmalloc - allocate virtually continguos memory 2981da177e4SLinus Torvalds * 2991da177e4SLinus Torvalds * @size: allocation size 3001da177e4SLinus Torvalds * 3011da177e4SLinus Torvalds * Allocate enough pages to cover @size from the page level 3021da177e4SLinus Torvalds * allocator and map them into continguos kernel virtual space. 3031da177e4SLinus Torvalds * 304c1c8897fSMichael Opdenacker * For tight control over page level allocator and protection flags 3051da177e4SLinus Torvalds * use __vmalloc() instead. 3061da177e4SLinus Torvalds */ 3071da177e4SLinus Torvalds void *vmalloc(unsigned long size) 3081da177e4SLinus Torvalds { 3091da177e4SLinus Torvalds return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); 3101da177e4SLinus Torvalds } 311f6138882SAndrew Morton EXPORT_SYMBOL(vmalloc); 312f6138882SAndrew Morton 313e1ca7788SDave Young /* 314e1ca7788SDave Young * vzalloc - allocate virtually continguos memory with zero fill 315e1ca7788SDave Young * 316e1ca7788SDave Young * @size: allocation size 317e1ca7788SDave Young * 318e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 319e1ca7788SDave Young * allocator and map them into continguos kernel virtual space. 320e1ca7788SDave Young * The memory allocated is set to zero. 321e1ca7788SDave Young * 322e1ca7788SDave Young * For tight control over page level allocator and protection flags 323e1ca7788SDave Young * use __vmalloc() instead. 324e1ca7788SDave Young */ 325e1ca7788SDave Young void *vzalloc(unsigned long size) 326e1ca7788SDave Young { 327e1ca7788SDave Young return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, 328e1ca7788SDave Young PAGE_KERNEL); 329e1ca7788SDave Young } 330e1ca7788SDave Young EXPORT_SYMBOL(vzalloc); 331e1ca7788SDave Young 332e1ca7788SDave Young /** 333e1ca7788SDave Young * vmalloc_node - allocate memory on a specific node 334e1ca7788SDave Young * @size: allocation size 335e1ca7788SDave Young * @node: numa node 336e1ca7788SDave Young * 337e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 338e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 339e1ca7788SDave Young * 340e1ca7788SDave Young * For tight control over page level allocator and protection flags 341e1ca7788SDave Young * use __vmalloc() instead. 342e1ca7788SDave Young */ 343f6138882SAndrew Morton void *vmalloc_node(unsigned long size, int node) 344f6138882SAndrew Morton { 345f6138882SAndrew Morton return vmalloc(size); 346f6138882SAndrew Morton } 3479a14f653SPaul Mundt EXPORT_SYMBOL(vmalloc_node); 348e1ca7788SDave Young 349e1ca7788SDave Young /** 350e1ca7788SDave Young * vzalloc_node - allocate memory on a specific node with zero fill 351e1ca7788SDave Young * @size: allocation size 352e1ca7788SDave Young * @node: numa node 353e1ca7788SDave Young * 354e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 355e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 356e1ca7788SDave Young * The memory allocated is set to zero. 357e1ca7788SDave Young * 358e1ca7788SDave Young * For tight control over page level allocator and protection flags 359e1ca7788SDave Young * use __vmalloc() instead. 360e1ca7788SDave Young */ 361e1ca7788SDave Young void *vzalloc_node(unsigned long size, int node) 362e1ca7788SDave Young { 363e1ca7788SDave Young return vzalloc(size); 364e1ca7788SDave Young } 365e1ca7788SDave Young EXPORT_SYMBOL(vzalloc_node); 3661da177e4SLinus Torvalds 3671af446edSPaul Mundt #ifndef PAGE_KERNEL_EXEC 3681af446edSPaul Mundt # define PAGE_KERNEL_EXEC PAGE_KERNEL 3691af446edSPaul Mundt #endif 3701af446edSPaul Mundt 3711af446edSPaul Mundt /** 3721af446edSPaul Mundt * vmalloc_exec - allocate virtually contiguous, executable memory 3731af446edSPaul Mundt * @size: allocation size 3741af446edSPaul Mundt * 3751af446edSPaul Mundt * Kernel-internal function to allocate enough pages to cover @size 3761af446edSPaul Mundt * the page level allocator and map them into contiguous and 3771af446edSPaul Mundt * executable kernel virtual space. 3781af446edSPaul Mundt * 3791af446edSPaul Mundt * For tight control over page level allocator and protection flags 3801af446edSPaul Mundt * use __vmalloc() instead. 3811af446edSPaul Mundt */ 3821af446edSPaul Mundt 3831af446edSPaul Mundt void *vmalloc_exec(unsigned long size) 3841af446edSPaul Mundt { 3851af446edSPaul Mundt return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); 3861af446edSPaul Mundt } 3871af446edSPaul Mundt 388b5073173SPaul Mundt /** 389b5073173SPaul Mundt * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 3901da177e4SLinus Torvalds * @size: allocation size 3911da177e4SLinus Torvalds * 3921da177e4SLinus Torvalds * Allocate enough 32bit PA addressable pages to cover @size from the 3931da177e4SLinus Torvalds * page level allocator and map them into continguos kernel virtual space. 3941da177e4SLinus Torvalds */ 3951da177e4SLinus Torvalds void *vmalloc_32(unsigned long size) 3961da177e4SLinus Torvalds { 3971da177e4SLinus Torvalds return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); 3981da177e4SLinus Torvalds } 399b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32); 400b5073173SPaul Mundt 401b5073173SPaul Mundt /** 402b5073173SPaul Mundt * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 403b5073173SPaul Mundt * @size: allocation size 404b5073173SPaul Mundt * 405b5073173SPaul Mundt * The resulting memory area is 32bit addressable and zeroed so it can be 406b5073173SPaul Mundt * mapped to userspace without leaking data. 407f905bc44SPaul Mundt * 408f905bc44SPaul Mundt * VM_USERMAP is set on the corresponding VMA so that subsequent calls to 409f905bc44SPaul Mundt * remap_vmalloc_range() are permissible. 410b5073173SPaul Mundt */ 411b5073173SPaul Mundt void *vmalloc_32_user(unsigned long size) 412b5073173SPaul Mundt { 413f905bc44SPaul Mundt /* 414f905bc44SPaul Mundt * We'll have to sort out the ZONE_DMA bits for 64-bit, 415f905bc44SPaul Mundt * but for now this can simply use vmalloc_user() directly. 416f905bc44SPaul Mundt */ 417f905bc44SPaul Mundt return vmalloc_user(size); 418b5073173SPaul Mundt } 419b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32_user); 4201da177e4SLinus Torvalds 4211da177e4SLinus Torvalds void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) 4221da177e4SLinus Torvalds { 4231da177e4SLinus Torvalds BUG(); 4241da177e4SLinus Torvalds return NULL; 4251da177e4SLinus Torvalds } 426b5073173SPaul Mundt EXPORT_SYMBOL(vmap); 4271da177e4SLinus Torvalds 428b3bdda02SChristoph Lameter void vunmap(const void *addr) 4291da177e4SLinus Torvalds { 4301da177e4SLinus Torvalds BUG(); 4311da177e4SLinus Torvalds } 432b5073173SPaul Mundt EXPORT_SYMBOL(vunmap); 4331da177e4SLinus Torvalds 434eb6434d9SPaul Mundt void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) 435eb6434d9SPaul Mundt { 436eb6434d9SPaul Mundt BUG(); 437eb6434d9SPaul Mundt return NULL; 438eb6434d9SPaul Mundt } 439eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_map_ram); 440eb6434d9SPaul Mundt 441eb6434d9SPaul Mundt void vm_unmap_ram(const void *mem, unsigned int count) 442eb6434d9SPaul Mundt { 443eb6434d9SPaul Mundt BUG(); 444eb6434d9SPaul Mundt } 445eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_unmap_ram); 446eb6434d9SPaul Mundt 447eb6434d9SPaul Mundt void vm_unmap_aliases(void) 448eb6434d9SPaul Mundt { 449eb6434d9SPaul Mundt } 450eb6434d9SPaul Mundt EXPORT_SYMBOL_GPL(vm_unmap_aliases); 451eb6434d9SPaul Mundt 4521da177e4SLinus Torvalds /* 4531eeb66a1SChristoph Hellwig * Implement a stub for vmalloc_sync_all() if the architecture chose not to 4541eeb66a1SChristoph Hellwig * have one. 4551eeb66a1SChristoph Hellwig */ 4561eeb66a1SChristoph Hellwig void __attribute__((weak)) vmalloc_sync_all(void) 4571eeb66a1SChristoph Hellwig { 4581eeb66a1SChristoph Hellwig } 4591eeb66a1SChristoph Hellwig 46029c185e5SPaul Mundt /** 46129c185e5SPaul Mundt * alloc_vm_area - allocate a range of kernel address space 46229c185e5SPaul Mundt * @size: size of the area 46329c185e5SPaul Mundt * 46429c185e5SPaul Mundt * Returns: NULL on failure, vm_struct on success 46529c185e5SPaul Mundt * 46629c185e5SPaul Mundt * This function reserves a range of kernel address space, and 46729c185e5SPaul Mundt * allocates pagetables to map that range. No actual mappings 46829c185e5SPaul Mundt * are created. If the kernel address space is not shared 46929c185e5SPaul Mundt * between processes, it syncs the pagetable across all 47029c185e5SPaul Mundt * processes. 47129c185e5SPaul Mundt */ 472cd12909cSDavid Vrabel struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) 47329c185e5SPaul Mundt { 47429c185e5SPaul Mundt BUG(); 47529c185e5SPaul Mundt return NULL; 47629c185e5SPaul Mundt } 47729c185e5SPaul Mundt EXPORT_SYMBOL_GPL(alloc_vm_area); 47829c185e5SPaul Mundt 47929c185e5SPaul Mundt void free_vm_area(struct vm_struct *area) 48029c185e5SPaul Mundt { 48129c185e5SPaul Mundt BUG(); 48229c185e5SPaul Mundt } 48329c185e5SPaul Mundt EXPORT_SYMBOL_GPL(free_vm_area); 48429c185e5SPaul Mundt 485b5073173SPaul Mundt int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 486b5073173SPaul Mundt struct page *page) 487b5073173SPaul Mundt { 488b5073173SPaul Mundt return -EINVAL; 489b5073173SPaul Mundt } 490b5073173SPaul Mundt EXPORT_SYMBOL(vm_insert_page); 491b5073173SPaul Mundt 4921eeb66a1SChristoph Hellwig /* 4931da177e4SLinus Torvalds * sys_brk() for the most part doesn't need the global kernel 4941da177e4SLinus Torvalds * lock, except when an application is doing something nasty 4951da177e4SLinus Torvalds * like trying to un-brk an area that has already been mapped 4961da177e4SLinus Torvalds * to a regular file. in this case, the unmapping will need 4971da177e4SLinus Torvalds * to invoke file system routines that need the global lock. 4981da177e4SLinus Torvalds */ 4996a6160a7SHeiko Carstens SYSCALL_DEFINE1(brk, unsigned long, brk) 5001da177e4SLinus Torvalds { 5011da177e4SLinus Torvalds struct mm_struct *mm = current->mm; 5021da177e4SLinus Torvalds 5031da177e4SLinus Torvalds if (brk < mm->start_brk || brk > mm->context.end_brk) 5041da177e4SLinus Torvalds return mm->brk; 5051da177e4SLinus Torvalds 5061da177e4SLinus Torvalds if (mm->brk == brk) 5071da177e4SLinus Torvalds return mm->brk; 5081da177e4SLinus Torvalds 5091da177e4SLinus Torvalds /* 5101da177e4SLinus Torvalds * Always allow shrinking brk 5111da177e4SLinus Torvalds */ 5121da177e4SLinus Torvalds if (brk <= mm->brk) { 5131da177e4SLinus Torvalds mm->brk = brk; 5141da177e4SLinus Torvalds return brk; 5151da177e4SLinus Torvalds } 5161da177e4SLinus Torvalds 5171da177e4SLinus Torvalds /* 5181da177e4SLinus Torvalds * Ok, looks good - let it rip. 5191da177e4SLinus Torvalds */ 520cfe79c00SMike Frysinger flush_icache_range(mm->brk, brk); 5211da177e4SLinus Torvalds return mm->brk = brk; 5221da177e4SLinus Torvalds } 5231da177e4SLinus Torvalds 5248feae131SDavid Howells /* 5258feae131SDavid Howells * initialise the VMA and region record slabs 5268feae131SDavid Howells */ 5278feae131SDavid Howells void __init mmap_init(void) 5281da177e4SLinus Torvalds { 52900a62ce9SKOSAKI Motohiro int ret; 53000a62ce9SKOSAKI Motohiro 53100a62ce9SKOSAKI Motohiro ret = percpu_counter_init(&vm_committed_as, 0); 53200a62ce9SKOSAKI Motohiro VM_BUG_ON(ret); 53333e5d769SDavid Howells vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC); 5348feae131SDavid Howells } 5351da177e4SLinus Torvalds 5368feae131SDavid Howells /* 5378feae131SDavid Howells * validate the region tree 5388feae131SDavid Howells * - the caller must hold the region lock 5398feae131SDavid Howells */ 5408feae131SDavid Howells #ifdef CONFIG_DEBUG_NOMMU_REGIONS 5418feae131SDavid Howells static noinline void validate_nommu_regions(void) 5428feae131SDavid Howells { 5438feae131SDavid Howells struct vm_region *region, *last; 5448feae131SDavid Howells struct rb_node *p, *lastp; 5451da177e4SLinus Torvalds 5468feae131SDavid Howells lastp = rb_first(&nommu_region_tree); 5478feae131SDavid Howells if (!lastp) 5488feae131SDavid Howells return; 5498feae131SDavid Howells 5508feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 55133e5d769SDavid Howells BUG_ON(unlikely(last->vm_end <= last->vm_start)); 55233e5d769SDavid Howells BUG_ON(unlikely(last->vm_top < last->vm_end)); 5538feae131SDavid Howells 5548feae131SDavid Howells while ((p = rb_next(lastp))) { 5558feae131SDavid Howells region = rb_entry(p, struct vm_region, vm_rb); 5568feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 5578feae131SDavid Howells 55833e5d769SDavid Howells BUG_ON(unlikely(region->vm_end <= region->vm_start)); 55933e5d769SDavid Howells BUG_ON(unlikely(region->vm_top < region->vm_end)); 56033e5d769SDavid Howells BUG_ON(unlikely(region->vm_start < last->vm_top)); 5618feae131SDavid Howells 5628feae131SDavid Howells lastp = p; 5631da177e4SLinus Torvalds } 5641da177e4SLinus Torvalds } 5658feae131SDavid Howells #else 56633e5d769SDavid Howells static void validate_nommu_regions(void) 56733e5d769SDavid Howells { 56833e5d769SDavid Howells } 5698feae131SDavid Howells #endif 5708feae131SDavid Howells 5718feae131SDavid Howells /* 5728feae131SDavid Howells * add a region into the global tree 5738feae131SDavid Howells */ 5748feae131SDavid Howells static void add_nommu_region(struct vm_region *region) 5758feae131SDavid Howells { 5768feae131SDavid Howells struct vm_region *pregion; 5778feae131SDavid Howells struct rb_node **p, *parent; 5788feae131SDavid Howells 5798feae131SDavid Howells validate_nommu_regions(); 5808feae131SDavid Howells 5818feae131SDavid Howells parent = NULL; 5828feae131SDavid Howells p = &nommu_region_tree.rb_node; 5838feae131SDavid Howells while (*p) { 5848feae131SDavid Howells parent = *p; 5858feae131SDavid Howells pregion = rb_entry(parent, struct vm_region, vm_rb); 5868feae131SDavid Howells if (region->vm_start < pregion->vm_start) 5878feae131SDavid Howells p = &(*p)->rb_left; 5888feae131SDavid Howells else if (region->vm_start > pregion->vm_start) 5898feae131SDavid Howells p = &(*p)->rb_right; 5908feae131SDavid Howells else if (pregion == region) 5918feae131SDavid Howells return; 5928feae131SDavid Howells else 5938feae131SDavid Howells BUG(); 5948feae131SDavid Howells } 5958feae131SDavid Howells 5968feae131SDavid Howells rb_link_node(®ion->vm_rb, parent, p); 5978feae131SDavid Howells rb_insert_color(®ion->vm_rb, &nommu_region_tree); 5988feae131SDavid Howells 5998feae131SDavid Howells validate_nommu_regions(); 6008feae131SDavid Howells } 6018feae131SDavid Howells 6028feae131SDavid Howells /* 6038feae131SDavid Howells * delete a region from the global tree 6048feae131SDavid Howells */ 6058feae131SDavid Howells static void delete_nommu_region(struct vm_region *region) 6068feae131SDavid Howells { 6078feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 6088feae131SDavid Howells 6098feae131SDavid Howells validate_nommu_regions(); 6108feae131SDavid Howells rb_erase(®ion->vm_rb, &nommu_region_tree); 6118feae131SDavid Howells validate_nommu_regions(); 6128feae131SDavid Howells } 6138feae131SDavid Howells 6148feae131SDavid Howells /* 6158feae131SDavid Howells * free a contiguous series of pages 6168feae131SDavid Howells */ 6178feae131SDavid Howells static void free_page_series(unsigned long from, unsigned long to) 6188feae131SDavid Howells { 6198feae131SDavid Howells for (; from < to; from += PAGE_SIZE) { 6208feae131SDavid Howells struct page *page = virt_to_page(from); 6218feae131SDavid Howells 6228feae131SDavid Howells kdebug("- free %lx", from); 62333e5d769SDavid Howells atomic_long_dec(&mmap_pages_allocated); 6248feae131SDavid Howells if (page_count(page) != 1) 62533e5d769SDavid Howells kdebug("free page %p: refcount not one: %d", 62633e5d769SDavid Howells page, page_count(page)); 6278feae131SDavid Howells put_page(page); 6288feae131SDavid Howells } 6298feae131SDavid Howells } 6308feae131SDavid Howells 6318feae131SDavid Howells /* 6328feae131SDavid Howells * release a reference to a region 63333e5d769SDavid Howells * - the caller must hold the region semaphore for writing, which this releases 634dd8632a1SPaul Mundt * - the region may not have been added to the tree yet, in which case vm_top 6358feae131SDavid Howells * will equal vm_start 6368feae131SDavid Howells */ 6378feae131SDavid Howells static void __put_nommu_region(struct vm_region *region) 6388feae131SDavid Howells __releases(nommu_region_sem) 6398feae131SDavid Howells { 6401e2ae599SDavid Howells kenter("%p{%d}", region, region->vm_usage); 6418feae131SDavid Howells 6428feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 6438feae131SDavid Howells 6441e2ae599SDavid Howells if (--region->vm_usage == 0) { 645dd8632a1SPaul Mundt if (region->vm_top > region->vm_start) 6468feae131SDavid Howells delete_nommu_region(region); 6478feae131SDavid Howells up_write(&nommu_region_sem); 6488feae131SDavid Howells 6498feae131SDavid Howells if (region->vm_file) 6508feae131SDavid Howells fput(region->vm_file); 6518feae131SDavid Howells 6528feae131SDavid Howells /* IO memory and memory shared directly out of the pagecache 6538feae131SDavid Howells * from ramfs/tmpfs mustn't be released here */ 6548feae131SDavid Howells if (region->vm_flags & VM_MAPPED_COPY) { 6558feae131SDavid Howells kdebug("free series"); 656dd8632a1SPaul Mundt free_page_series(region->vm_start, region->vm_top); 6578feae131SDavid Howells } 6588feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 6598feae131SDavid Howells } else { 6608feae131SDavid Howells up_write(&nommu_region_sem); 6618feae131SDavid Howells } 6628feae131SDavid Howells } 6638feae131SDavid Howells 6648feae131SDavid Howells /* 6658feae131SDavid Howells * release a reference to a region 6668feae131SDavid Howells */ 6678feae131SDavid Howells static void put_nommu_region(struct vm_region *region) 6688feae131SDavid Howells { 6698feae131SDavid Howells down_write(&nommu_region_sem); 6708feae131SDavid Howells __put_nommu_region(region); 6718feae131SDavid Howells } 6721da177e4SLinus Torvalds 6733034097aSDavid Howells /* 674eb8cdec4SBernd Schmidt * update protection on a vma 675eb8cdec4SBernd Schmidt */ 676eb8cdec4SBernd Schmidt static void protect_vma(struct vm_area_struct *vma, unsigned long flags) 677eb8cdec4SBernd Schmidt { 678eb8cdec4SBernd Schmidt #ifdef CONFIG_MPU 679eb8cdec4SBernd Schmidt struct mm_struct *mm = vma->vm_mm; 680eb8cdec4SBernd Schmidt long start = vma->vm_start & PAGE_MASK; 681eb8cdec4SBernd Schmidt while (start < vma->vm_end) { 682eb8cdec4SBernd Schmidt protect_page(mm, start, flags); 683eb8cdec4SBernd Schmidt start += PAGE_SIZE; 684eb8cdec4SBernd Schmidt } 685eb8cdec4SBernd Schmidt update_protections(mm); 686eb8cdec4SBernd Schmidt #endif 687eb8cdec4SBernd Schmidt } 688eb8cdec4SBernd Schmidt 689eb8cdec4SBernd Schmidt /* 6903034097aSDavid Howells * add a VMA into a process's mm_struct in the appropriate place in the list 6918feae131SDavid Howells * and tree and add to the address space's page tree also if not an anonymous 6928feae131SDavid Howells * page 6933034097aSDavid Howells * - should be called with mm->mmap_sem held writelocked 6943034097aSDavid Howells */ 6958feae131SDavid Howells static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) 6963034097aSDavid Howells { 6976038def0SNamhyung Kim struct vm_area_struct *pvma, *prev; 6988feae131SDavid Howells struct address_space *mapping; 6996038def0SNamhyung Kim struct rb_node **p, *parent, *rb_prev; 7003034097aSDavid Howells 7018feae131SDavid Howells kenter(",%p", vma); 7028feae131SDavid Howells 7038feae131SDavid Howells BUG_ON(!vma->vm_region); 7048feae131SDavid Howells 7058feae131SDavid Howells mm->map_count++; 7068feae131SDavid Howells vma->vm_mm = mm; 7078feae131SDavid Howells 708eb8cdec4SBernd Schmidt protect_vma(vma, vma->vm_flags); 709eb8cdec4SBernd Schmidt 7108feae131SDavid Howells /* add the VMA to the mapping */ 7118feae131SDavid Howells if (vma->vm_file) { 7128feae131SDavid Howells mapping = vma->vm_file->f_mapping; 7138feae131SDavid Howells 714918e556eSDavid Howells mutex_lock(&mapping->i_mmap_mutex); 7158feae131SDavid Howells flush_dcache_mmap_lock(mapping); 7166b2dbba8SMichel Lespinasse vma_interval_tree_insert(vma, &mapping->i_mmap); 7178feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 718918e556eSDavid Howells mutex_unlock(&mapping->i_mmap_mutex); 7198feae131SDavid Howells } 7208feae131SDavid Howells 7218feae131SDavid Howells /* add the VMA to the tree */ 7226038def0SNamhyung Kim parent = rb_prev = NULL; 7238feae131SDavid Howells p = &mm->mm_rb.rb_node; 7248feae131SDavid Howells while (*p) { 7258feae131SDavid Howells parent = *p; 7268feae131SDavid Howells pvma = rb_entry(parent, struct vm_area_struct, vm_rb); 7278feae131SDavid Howells 7288feae131SDavid Howells /* sort by: start addr, end addr, VMA struct addr in that order 7298feae131SDavid Howells * (the latter is necessary as we may get identical VMAs) */ 7308feae131SDavid Howells if (vma->vm_start < pvma->vm_start) 7318feae131SDavid Howells p = &(*p)->rb_left; 7326038def0SNamhyung Kim else if (vma->vm_start > pvma->vm_start) { 7336038def0SNamhyung Kim rb_prev = parent; 7348feae131SDavid Howells p = &(*p)->rb_right; 7356038def0SNamhyung Kim } else if (vma->vm_end < pvma->vm_end) 7368feae131SDavid Howells p = &(*p)->rb_left; 7376038def0SNamhyung Kim else if (vma->vm_end > pvma->vm_end) { 7386038def0SNamhyung Kim rb_prev = parent; 7398feae131SDavid Howells p = &(*p)->rb_right; 7406038def0SNamhyung Kim } else if (vma < pvma) 7418feae131SDavid Howells p = &(*p)->rb_left; 7426038def0SNamhyung Kim else if (vma > pvma) { 7436038def0SNamhyung Kim rb_prev = parent; 7448feae131SDavid Howells p = &(*p)->rb_right; 7456038def0SNamhyung Kim } else 7468feae131SDavid Howells BUG(); 7478feae131SDavid Howells } 7488feae131SDavid Howells 7498feae131SDavid Howells rb_link_node(&vma->vm_rb, parent, p); 7508feae131SDavid Howells rb_insert_color(&vma->vm_rb, &mm->mm_rb); 7518feae131SDavid Howells 7528feae131SDavid Howells /* add VMA to the VMA list also */ 7536038def0SNamhyung Kim prev = NULL; 7546038def0SNamhyung Kim if (rb_prev) 7556038def0SNamhyung Kim prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); 7563034097aSDavid Howells 7576038def0SNamhyung Kim __vma_link_list(mm, vma, prev, parent); 7588feae131SDavid Howells } 7598feae131SDavid Howells 7608feae131SDavid Howells /* 7618feae131SDavid Howells * delete a VMA from its owning mm_struct and address space 7628feae131SDavid Howells */ 7638feae131SDavid Howells static void delete_vma_from_mm(struct vm_area_struct *vma) 7648feae131SDavid Howells { 7658feae131SDavid Howells struct address_space *mapping; 7668feae131SDavid Howells struct mm_struct *mm = vma->vm_mm; 7678feae131SDavid Howells 7688feae131SDavid Howells kenter("%p", vma); 7698feae131SDavid Howells 770eb8cdec4SBernd Schmidt protect_vma(vma, 0); 771eb8cdec4SBernd Schmidt 7728feae131SDavid Howells mm->map_count--; 7738feae131SDavid Howells if (mm->mmap_cache == vma) 7748feae131SDavid Howells mm->mmap_cache = NULL; 7758feae131SDavid Howells 7768feae131SDavid Howells /* remove the VMA from the mapping */ 7778feae131SDavid Howells if (vma->vm_file) { 7788feae131SDavid Howells mapping = vma->vm_file->f_mapping; 7798feae131SDavid Howells 780918e556eSDavid Howells mutex_lock(&mapping->i_mmap_mutex); 7818feae131SDavid Howells flush_dcache_mmap_lock(mapping); 7826b2dbba8SMichel Lespinasse vma_interval_tree_remove(vma, &mapping->i_mmap); 7838feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 784918e556eSDavid Howells mutex_unlock(&mapping->i_mmap_mutex); 7858feae131SDavid Howells } 7868feae131SDavid Howells 7878feae131SDavid Howells /* remove from the MM's tree and list */ 7888feae131SDavid Howells rb_erase(&vma->vm_rb, &mm->mm_rb); 789b951bf2cSNamhyung Kim 790b951bf2cSNamhyung Kim if (vma->vm_prev) 791b951bf2cSNamhyung Kim vma->vm_prev->vm_next = vma->vm_next; 792b951bf2cSNamhyung Kim else 793b951bf2cSNamhyung Kim mm->mmap = vma->vm_next; 794b951bf2cSNamhyung Kim 795b951bf2cSNamhyung Kim if (vma->vm_next) 796b951bf2cSNamhyung Kim vma->vm_next->vm_prev = vma->vm_prev; 7978feae131SDavid Howells } 7988feae131SDavid Howells 7998feae131SDavid Howells /* 8008feae131SDavid Howells * destroy a VMA record 8018feae131SDavid Howells */ 8028feae131SDavid Howells static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) 8038feae131SDavid Howells { 8048feae131SDavid Howells kenter("%p", vma); 8058feae131SDavid Howells if (vma->vm_ops && vma->vm_ops->close) 8068feae131SDavid Howells vma->vm_ops->close(vma); 807e9714acfSKonstantin Khlebnikov if (vma->vm_file) 8088feae131SDavid Howells fput(vma->vm_file); 8098feae131SDavid Howells put_nommu_region(vma->vm_region); 8108feae131SDavid Howells kmem_cache_free(vm_area_cachep, vma); 8113034097aSDavid Howells } 8123034097aSDavid Howells 8133034097aSDavid Howells /* 8143034097aSDavid Howells * look up the first VMA in which addr resides, NULL if none 8153034097aSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 8163034097aSDavid Howells */ 8173034097aSDavid Howells struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) 8183034097aSDavid Howells { 8198feae131SDavid Howells struct vm_area_struct *vma; 8203034097aSDavid Howells 8218feae131SDavid Howells /* check the cache first */ 8228feae131SDavid Howells vma = mm->mmap_cache; 8238feae131SDavid Howells if (vma && vma->vm_start <= addr && vma->vm_end > addr) 8248feae131SDavid Howells return vma; 8258feae131SDavid Howells 826e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 8278feae131SDavid Howells * resides) */ 828e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 8298feae131SDavid Howells if (vma->vm_start > addr) 8308feae131SDavid Howells return NULL; 8318feae131SDavid Howells if (vma->vm_end > addr) { 8328feae131SDavid Howells mm->mmap_cache = vma; 8338feae131SDavid Howells return vma; 8343034097aSDavid Howells } 8358feae131SDavid Howells } 8363034097aSDavid Howells 8373034097aSDavid Howells return NULL; 8383034097aSDavid Howells } 8393034097aSDavid Howells EXPORT_SYMBOL(find_vma); 8403034097aSDavid Howells 8413034097aSDavid Howells /* 842930e652aSDavid Howells * find a VMA 843930e652aSDavid Howells * - we don't extend stack VMAs under NOMMU conditions 844930e652aSDavid Howells */ 845930e652aSDavid Howells struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) 846930e652aSDavid Howells { 8477561e8caSDavid Howells return find_vma(mm, addr); 848930e652aSDavid Howells } 849930e652aSDavid Howells 8508feae131SDavid Howells /* 8518feae131SDavid Howells * expand a stack to a given address 8528feae131SDavid Howells * - not supported under NOMMU conditions 8538feae131SDavid Howells */ 85457c8f63eSGreg Ungerer int expand_stack(struct vm_area_struct *vma, unsigned long address) 85557c8f63eSGreg Ungerer { 85657c8f63eSGreg Ungerer return -ENOMEM; 85757c8f63eSGreg Ungerer } 85857c8f63eSGreg Ungerer 859930e652aSDavid Howells /* 8606fa5f80bSDavid Howells * look up the first VMA exactly that exactly matches addr 8616fa5f80bSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 8626fa5f80bSDavid Howells */ 8638feae131SDavid Howells static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, 8648feae131SDavid Howells unsigned long addr, 8658feae131SDavid Howells unsigned long len) 8661da177e4SLinus Torvalds { 8671da177e4SLinus Torvalds struct vm_area_struct *vma; 8688feae131SDavid Howells unsigned long end = addr + len; 8691da177e4SLinus Torvalds 8708feae131SDavid Howells /* check the cache first */ 8718feae131SDavid Howells vma = mm->mmap_cache; 8728feae131SDavid Howells if (vma && vma->vm_start == addr && vma->vm_end == end) 8731da177e4SLinus Torvalds return vma; 8748feae131SDavid Howells 875e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 8768feae131SDavid Howells * resides) */ 877e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 8788feae131SDavid Howells if (vma->vm_start < addr) 8798feae131SDavid Howells continue; 8808feae131SDavid Howells if (vma->vm_start > addr) 8818feae131SDavid Howells return NULL; 8828feae131SDavid Howells if (vma->vm_end == end) { 8838feae131SDavid Howells mm->mmap_cache = vma; 8848feae131SDavid Howells return vma; 8858feae131SDavid Howells } 8861da177e4SLinus Torvalds } 8871da177e4SLinus Torvalds 8881da177e4SLinus Torvalds return NULL; 8891da177e4SLinus Torvalds } 8901da177e4SLinus Torvalds 8913034097aSDavid Howells /* 8921da177e4SLinus Torvalds * determine whether a mapping should be permitted and, if so, what sort of 8931da177e4SLinus Torvalds * mapping we're capable of supporting 8941da177e4SLinus Torvalds */ 8951da177e4SLinus Torvalds static int validate_mmap_request(struct file *file, 8961da177e4SLinus Torvalds unsigned long addr, 8971da177e4SLinus Torvalds unsigned long len, 8981da177e4SLinus Torvalds unsigned long prot, 8991da177e4SLinus Torvalds unsigned long flags, 9001da177e4SLinus Torvalds unsigned long pgoff, 9011da177e4SLinus Torvalds unsigned long *_capabilities) 9021da177e4SLinus Torvalds { 9038feae131SDavid Howells unsigned long capabilities, rlen; 9041da177e4SLinus Torvalds int ret; 9051da177e4SLinus Torvalds 9061da177e4SLinus Torvalds /* do the simple checks first */ 90706aab5a3SDavid Howells if (flags & MAP_FIXED) { 9081da177e4SLinus Torvalds printk(KERN_DEBUG 9091da177e4SLinus Torvalds "%d: Can't do fixed-address/overlay mmap of RAM\n", 9101da177e4SLinus Torvalds current->pid); 9111da177e4SLinus Torvalds return -EINVAL; 9121da177e4SLinus Torvalds } 9131da177e4SLinus Torvalds 9141da177e4SLinus Torvalds if ((flags & MAP_TYPE) != MAP_PRIVATE && 9151da177e4SLinus Torvalds (flags & MAP_TYPE) != MAP_SHARED) 9161da177e4SLinus Torvalds return -EINVAL; 9171da177e4SLinus Torvalds 918f81cff0dSMike Frysinger if (!len) 9191da177e4SLinus Torvalds return -EINVAL; 9201da177e4SLinus Torvalds 921f81cff0dSMike Frysinger /* Careful about overflows.. */ 9228feae131SDavid Howells rlen = PAGE_ALIGN(len); 9238feae131SDavid Howells if (!rlen || rlen > TASK_SIZE) 924f81cff0dSMike Frysinger return -ENOMEM; 925f81cff0dSMike Frysinger 9261da177e4SLinus Torvalds /* offset overflow? */ 9278feae131SDavid Howells if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) 928f81cff0dSMike Frysinger return -EOVERFLOW; 9291da177e4SLinus Torvalds 9301da177e4SLinus Torvalds if (file) { 9311da177e4SLinus Torvalds /* validate file mapping requests */ 9321da177e4SLinus Torvalds struct address_space *mapping; 9331da177e4SLinus Torvalds 9341da177e4SLinus Torvalds /* files must support mmap */ 9351da177e4SLinus Torvalds if (!file->f_op || !file->f_op->mmap) 9361da177e4SLinus Torvalds return -ENODEV; 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds /* work out if what we've got could possibly be shared 9391da177e4SLinus Torvalds * - we support chardevs that provide their own "memory" 9401da177e4SLinus Torvalds * - we support files/blockdevs that are memory backed 9411da177e4SLinus Torvalds */ 9421da177e4SLinus Torvalds mapping = file->f_mapping; 9431da177e4SLinus Torvalds if (!mapping) 944*496ad9aaSAl Viro mapping = file_inode(file)->i_mapping; 9451da177e4SLinus Torvalds 9461da177e4SLinus Torvalds capabilities = 0; 9471da177e4SLinus Torvalds if (mapping && mapping->backing_dev_info) 9481da177e4SLinus Torvalds capabilities = mapping->backing_dev_info->capabilities; 9491da177e4SLinus Torvalds 9501da177e4SLinus Torvalds if (!capabilities) { 9511da177e4SLinus Torvalds /* no explicit capabilities set, so assume some 9521da177e4SLinus Torvalds * defaults */ 953*496ad9aaSAl Viro switch (file_inode(file)->i_mode & S_IFMT) { 9541da177e4SLinus Torvalds case S_IFREG: 9551da177e4SLinus Torvalds case S_IFBLK: 9561da177e4SLinus Torvalds capabilities = BDI_CAP_MAP_COPY; 9571da177e4SLinus Torvalds break; 9581da177e4SLinus Torvalds 9591da177e4SLinus Torvalds case S_IFCHR: 9601da177e4SLinus Torvalds capabilities = 9611da177e4SLinus Torvalds BDI_CAP_MAP_DIRECT | 9621da177e4SLinus Torvalds BDI_CAP_READ_MAP | 9631da177e4SLinus Torvalds BDI_CAP_WRITE_MAP; 9641da177e4SLinus Torvalds break; 9651da177e4SLinus Torvalds 9661da177e4SLinus Torvalds default: 9671da177e4SLinus Torvalds return -EINVAL; 9681da177e4SLinus Torvalds } 9691da177e4SLinus Torvalds } 9701da177e4SLinus Torvalds 9711da177e4SLinus Torvalds /* eliminate any capabilities that we can't support on this 9721da177e4SLinus Torvalds * device */ 9731da177e4SLinus Torvalds if (!file->f_op->get_unmapped_area) 9741da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 9751da177e4SLinus Torvalds if (!file->f_op->read) 9761da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_COPY; 9771da177e4SLinus Torvalds 97828d7a6aeSGraff Yang /* The file shall have been opened with read permission. */ 97928d7a6aeSGraff Yang if (!(file->f_mode & FMODE_READ)) 98028d7a6aeSGraff Yang return -EACCES; 98128d7a6aeSGraff Yang 9821da177e4SLinus Torvalds if (flags & MAP_SHARED) { 9831da177e4SLinus Torvalds /* do checks for writing, appending and locking */ 9841da177e4SLinus Torvalds if ((prot & PROT_WRITE) && 9851da177e4SLinus Torvalds !(file->f_mode & FMODE_WRITE)) 9861da177e4SLinus Torvalds return -EACCES; 9871da177e4SLinus Torvalds 988*496ad9aaSAl Viro if (IS_APPEND(file_inode(file)) && 9891da177e4SLinus Torvalds (file->f_mode & FMODE_WRITE)) 9901da177e4SLinus Torvalds return -EACCES; 9911da177e4SLinus Torvalds 992*496ad9aaSAl Viro if (locks_verify_locked(file_inode(file))) 9931da177e4SLinus Torvalds return -EAGAIN; 9941da177e4SLinus Torvalds 9951da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_DIRECT)) 9961da177e4SLinus Torvalds return -ENODEV; 9971da177e4SLinus Torvalds 9981da177e4SLinus Torvalds /* we mustn't privatise shared mappings */ 9991da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_COPY; 10001da177e4SLinus Torvalds } 10011da177e4SLinus Torvalds else { 10021da177e4SLinus Torvalds /* we're going to read the file into private memory we 10031da177e4SLinus Torvalds * allocate */ 10041da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_COPY)) 10051da177e4SLinus Torvalds return -ENODEV; 10061da177e4SLinus Torvalds 10071da177e4SLinus Torvalds /* we don't permit a private writable mapping to be 10081da177e4SLinus Torvalds * shared with the backing device */ 10091da177e4SLinus Torvalds if (prot & PROT_WRITE) 10101da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 10111da177e4SLinus Torvalds } 10121da177e4SLinus Torvalds 10133c7b2045SBernd Schmidt if (capabilities & BDI_CAP_MAP_DIRECT) { 10143c7b2045SBernd Schmidt if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || 10153c7b2045SBernd Schmidt ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || 10163c7b2045SBernd Schmidt ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) 10173c7b2045SBernd Schmidt ) { 10183c7b2045SBernd Schmidt capabilities &= ~BDI_CAP_MAP_DIRECT; 10193c7b2045SBernd Schmidt if (flags & MAP_SHARED) { 10203c7b2045SBernd Schmidt printk(KERN_WARNING 10213c7b2045SBernd Schmidt "MAP_SHARED not completely supported on !MMU\n"); 10223c7b2045SBernd Schmidt return -EINVAL; 10233c7b2045SBernd Schmidt } 10243c7b2045SBernd Schmidt } 10253c7b2045SBernd Schmidt } 10263c7b2045SBernd Schmidt 10271da177e4SLinus Torvalds /* handle executable mappings and implied executable 10281da177e4SLinus Torvalds * mappings */ 1029e9536ae7SJosef Sipek if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { 10301da177e4SLinus Torvalds if (prot & PROT_EXEC) 10311da177e4SLinus Torvalds return -EPERM; 10321da177e4SLinus Torvalds } 10331da177e4SLinus Torvalds else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { 10341da177e4SLinus Torvalds /* handle implication of PROT_EXEC by PROT_READ */ 10351da177e4SLinus Torvalds if (current->personality & READ_IMPLIES_EXEC) { 10361da177e4SLinus Torvalds if (capabilities & BDI_CAP_EXEC_MAP) 10371da177e4SLinus Torvalds prot |= PROT_EXEC; 10381da177e4SLinus Torvalds } 10391da177e4SLinus Torvalds } 10401da177e4SLinus Torvalds else if ((prot & PROT_READ) && 10411da177e4SLinus Torvalds (prot & PROT_EXEC) && 10421da177e4SLinus Torvalds !(capabilities & BDI_CAP_EXEC_MAP) 10431da177e4SLinus Torvalds ) { 10441da177e4SLinus Torvalds /* backing file is not executable, try to copy */ 10451da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 10461da177e4SLinus Torvalds } 10471da177e4SLinus Torvalds } 10481da177e4SLinus Torvalds else { 10491da177e4SLinus Torvalds /* anonymous mappings are always memory backed and can be 10501da177e4SLinus Torvalds * privately mapped 10511da177e4SLinus Torvalds */ 10521da177e4SLinus Torvalds capabilities = BDI_CAP_MAP_COPY; 10531da177e4SLinus Torvalds 10541da177e4SLinus Torvalds /* handle PROT_EXEC implication by PROT_READ */ 10551da177e4SLinus Torvalds if ((prot & PROT_READ) && 10561da177e4SLinus Torvalds (current->personality & READ_IMPLIES_EXEC)) 10571da177e4SLinus Torvalds prot |= PROT_EXEC; 10581da177e4SLinus Torvalds } 10591da177e4SLinus Torvalds 10601da177e4SLinus Torvalds /* allow the security API to have its say */ 1061e5467859SAl Viro ret = security_mmap_addr(addr); 1062e5467859SAl Viro if (ret < 0) 1063e5467859SAl Viro return ret; 10641da177e4SLinus Torvalds 10651da177e4SLinus Torvalds /* looks okay */ 10661da177e4SLinus Torvalds *_capabilities = capabilities; 10671da177e4SLinus Torvalds return 0; 10681da177e4SLinus Torvalds } 10691da177e4SLinus Torvalds 10701da177e4SLinus Torvalds /* 10711da177e4SLinus Torvalds * we've determined that we can make the mapping, now translate what we 10721da177e4SLinus Torvalds * now know into VMA flags 10731da177e4SLinus Torvalds */ 10741da177e4SLinus Torvalds static unsigned long determine_vm_flags(struct file *file, 10751da177e4SLinus Torvalds unsigned long prot, 10761da177e4SLinus Torvalds unsigned long flags, 10771da177e4SLinus Torvalds unsigned long capabilities) 10781da177e4SLinus Torvalds { 10791da177e4SLinus Torvalds unsigned long vm_flags; 10801da177e4SLinus Torvalds 10811da177e4SLinus Torvalds vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); 10821da177e4SLinus Torvalds /* vm_flags |= mm->def_flags; */ 10831da177e4SLinus Torvalds 10841da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_DIRECT)) { 10851da177e4SLinus Torvalds /* attempt to share read-only copies of mapped file chunks */ 10863c7b2045SBernd Schmidt vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; 10871da177e4SLinus Torvalds if (file && !(prot & PROT_WRITE)) 10881da177e4SLinus Torvalds vm_flags |= VM_MAYSHARE; 10893c7b2045SBernd Schmidt } else { 10901da177e4SLinus Torvalds /* overlay a shareable mapping on the backing device or inode 10911da177e4SLinus Torvalds * if possible - used for chardevs, ramfs/tmpfs/shmfs and 10921da177e4SLinus Torvalds * romfs/cramfs */ 10933c7b2045SBernd Schmidt vm_flags |= VM_MAYSHARE | (capabilities & BDI_CAP_VMFLAGS); 10941da177e4SLinus Torvalds if (flags & MAP_SHARED) 10953c7b2045SBernd Schmidt vm_flags |= VM_SHARED; 10961da177e4SLinus Torvalds } 10971da177e4SLinus Torvalds 10981da177e4SLinus Torvalds /* refuse to let anyone share private mappings with this process if 10991da177e4SLinus Torvalds * it's being traced - otherwise breakpoints set in it may interfere 11001da177e4SLinus Torvalds * with another untraced process 11011da177e4SLinus Torvalds */ 1102a288eeccSTejun Heo if ((flags & MAP_PRIVATE) && current->ptrace) 11031da177e4SLinus Torvalds vm_flags &= ~VM_MAYSHARE; 11041da177e4SLinus Torvalds 11051da177e4SLinus Torvalds return vm_flags; 11061da177e4SLinus Torvalds } 11071da177e4SLinus Torvalds 11081da177e4SLinus Torvalds /* 11098feae131SDavid Howells * set up a shared mapping on a file (the driver or filesystem provides and 11108feae131SDavid Howells * pins the storage) 11111da177e4SLinus Torvalds */ 11128feae131SDavid Howells static int do_mmap_shared_file(struct vm_area_struct *vma) 11131da177e4SLinus Torvalds { 11141da177e4SLinus Torvalds int ret; 11151da177e4SLinus Torvalds 11161da177e4SLinus Torvalds ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); 1117dd8632a1SPaul Mundt if (ret == 0) { 1118dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 1119645d83c5SDavid Howells return 0; 1120dd8632a1SPaul Mundt } 11211da177e4SLinus Torvalds if (ret != -ENOSYS) 11221da177e4SLinus Torvalds return ret; 11231da177e4SLinus Torvalds 11243fa30460SDavid Howells /* getting -ENOSYS indicates that direct mmap isn't possible (as 11253fa30460SDavid Howells * opposed to tried but failed) so we can only give a suitable error as 11263fa30460SDavid Howells * it's not possible to make a private copy if MAP_SHARED was given */ 11271da177e4SLinus Torvalds return -ENODEV; 11281da177e4SLinus Torvalds } 11291da177e4SLinus Torvalds 11301da177e4SLinus Torvalds /* 11311da177e4SLinus Torvalds * set up a private mapping or an anonymous shared mapping 11321da177e4SLinus Torvalds */ 11338feae131SDavid Howells static int do_mmap_private(struct vm_area_struct *vma, 11348feae131SDavid Howells struct vm_region *region, 1135645d83c5SDavid Howells unsigned long len, 1136645d83c5SDavid Howells unsigned long capabilities) 11371da177e4SLinus Torvalds { 11388feae131SDavid Howells struct page *pages; 1139f67d9b15SBob Liu unsigned long total, point, n; 11401da177e4SLinus Torvalds void *base; 11418feae131SDavid Howells int ret, order; 11421da177e4SLinus Torvalds 11431da177e4SLinus Torvalds /* invoke the file's mapping function so that it can keep track of 11441da177e4SLinus Torvalds * shared mappings on devices or memory 11451da177e4SLinus Torvalds * - VM_MAYSHARE will be set if it may attempt to share 11461da177e4SLinus Torvalds */ 1147645d83c5SDavid Howells if (capabilities & BDI_CAP_MAP_DIRECT) { 11481da177e4SLinus Torvalds ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); 1149dd8632a1SPaul Mundt if (ret == 0) { 11501da177e4SLinus Torvalds /* shouldn't return success if we're not sharing */ 1151dd8632a1SPaul Mundt BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); 1152dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 1153645d83c5SDavid Howells return 0; 11541da177e4SLinus Torvalds } 1155dd8632a1SPaul Mundt if (ret != -ENOSYS) 1156dd8632a1SPaul Mundt return ret; 11571da177e4SLinus Torvalds 11581da177e4SLinus Torvalds /* getting an ENOSYS error indicates that direct mmap isn't 11591da177e4SLinus Torvalds * possible (as opposed to tried but failed) so we'll try to 11601da177e4SLinus Torvalds * make a private copy of the data and map that instead */ 11611da177e4SLinus Torvalds } 11621da177e4SLinus Torvalds 11638feae131SDavid Howells 11641da177e4SLinus Torvalds /* allocate some memory to hold the mapping 11651da177e4SLinus Torvalds * - note that this may not return a page-aligned address if the object 11661da177e4SLinus Torvalds * we're allocating is smaller than a page 11671da177e4SLinus Torvalds */ 1168f67d9b15SBob Liu order = get_order(len); 11698feae131SDavid Howells kdebug("alloc order %d for %lx", order, len); 11708feae131SDavid Howells 11718feae131SDavid Howells pages = alloc_pages(GFP_KERNEL, order); 11728feae131SDavid Howells if (!pages) 11731da177e4SLinus Torvalds goto enomem; 11741da177e4SLinus Torvalds 11758feae131SDavid Howells total = 1 << order; 117633e5d769SDavid Howells atomic_long_add(total, &mmap_pages_allocated); 11771da177e4SLinus Torvalds 1178f67d9b15SBob Liu point = len >> PAGE_SHIFT; 1179dd8632a1SPaul Mundt 1180dd8632a1SPaul Mundt /* we allocated a power-of-2 sized page set, so we may want to trim off 1181dd8632a1SPaul Mundt * the excess */ 1182dd8632a1SPaul Mundt if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { 11838feae131SDavid Howells while (total > point) { 11848feae131SDavid Howells order = ilog2(total - point); 11858feae131SDavid Howells n = 1 << order; 11868feae131SDavid Howells kdebug("shave %lu/%lu @%lu", n, total - point, total); 118733e5d769SDavid Howells atomic_long_sub(n, &mmap_pages_allocated); 11888feae131SDavid Howells total -= n; 11898feae131SDavid Howells set_page_refcounted(pages + total); 11908feae131SDavid Howells __free_pages(pages + total, order); 11918feae131SDavid Howells } 1192dd8632a1SPaul Mundt } 11938feae131SDavid Howells 11948feae131SDavid Howells for (point = 1; point < total; point++) 11958feae131SDavid Howells set_page_refcounted(&pages[point]); 11968feae131SDavid Howells 11978feae131SDavid Howells base = page_address(pages); 11988feae131SDavid Howells region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; 11998feae131SDavid Howells region->vm_start = (unsigned long) base; 1200f67d9b15SBob Liu region->vm_end = region->vm_start + len; 1201dd8632a1SPaul Mundt region->vm_top = region->vm_start + (total << PAGE_SHIFT); 12028feae131SDavid Howells 12038feae131SDavid Howells vma->vm_start = region->vm_start; 12048feae131SDavid Howells vma->vm_end = region->vm_start + len; 12051da177e4SLinus Torvalds 12061da177e4SLinus Torvalds if (vma->vm_file) { 12071da177e4SLinus Torvalds /* read the contents of a file into the copy */ 12081da177e4SLinus Torvalds mm_segment_t old_fs; 12091da177e4SLinus Torvalds loff_t fpos; 12101da177e4SLinus Torvalds 12111da177e4SLinus Torvalds fpos = vma->vm_pgoff; 12121da177e4SLinus Torvalds fpos <<= PAGE_SHIFT; 12131da177e4SLinus Torvalds 12141da177e4SLinus Torvalds old_fs = get_fs(); 12151da177e4SLinus Torvalds set_fs(KERNEL_DS); 1216f67d9b15SBob Liu ret = vma->vm_file->f_op->read(vma->vm_file, base, len, &fpos); 12171da177e4SLinus Torvalds set_fs(old_fs); 12181da177e4SLinus Torvalds 12191da177e4SLinus Torvalds if (ret < 0) 12201da177e4SLinus Torvalds goto error_free; 12211da177e4SLinus Torvalds 12221da177e4SLinus Torvalds /* clear the last little bit */ 1223f67d9b15SBob Liu if (ret < len) 1224f67d9b15SBob Liu memset(base + ret, 0, len - ret); 12251da177e4SLinus Torvalds 12261da177e4SLinus Torvalds } 12271da177e4SLinus Torvalds 12281da177e4SLinus Torvalds return 0; 12291da177e4SLinus Torvalds 12301da177e4SLinus Torvalds error_free: 12317223bb4aSNamhyung Kim free_page_series(region->vm_start, region->vm_top); 12328feae131SDavid Howells region->vm_start = vma->vm_start = 0; 12338feae131SDavid Howells region->vm_end = vma->vm_end = 0; 1234dd8632a1SPaul Mundt region->vm_top = 0; 12351da177e4SLinus Torvalds return ret; 12361da177e4SLinus Torvalds 12371da177e4SLinus Torvalds enomem: 123805ae6fa3SGreg Ungerer printk("Allocation of length %lu from process %d (%s) failed\n", 123905ae6fa3SGreg Ungerer len, current->pid, current->comm); 12407bf02ea2SDavid Rientjes show_free_areas(0); 12411da177e4SLinus Torvalds return -ENOMEM; 12421da177e4SLinus Torvalds } 12431da177e4SLinus Torvalds 12441da177e4SLinus Torvalds /* 12451da177e4SLinus Torvalds * handle mapping creation for uClinux 12461da177e4SLinus Torvalds */ 1247e3fc629dSAl Viro unsigned long do_mmap_pgoff(struct file *file, 12481da177e4SLinus Torvalds unsigned long addr, 12491da177e4SLinus Torvalds unsigned long len, 12501da177e4SLinus Torvalds unsigned long prot, 12511da177e4SLinus Torvalds unsigned long flags, 12521da177e4SLinus Torvalds unsigned long pgoff) 12531da177e4SLinus Torvalds { 12548feae131SDavid Howells struct vm_area_struct *vma; 12558feae131SDavid Howells struct vm_region *region; 12561da177e4SLinus Torvalds struct rb_node *rb; 12578feae131SDavid Howells unsigned long capabilities, vm_flags, result; 12581da177e4SLinus Torvalds int ret; 12591da177e4SLinus Torvalds 12608feae131SDavid Howells kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff); 12618feae131SDavid Howells 12621da177e4SLinus Torvalds /* decide whether we should attempt the mapping, and if so what sort of 12631da177e4SLinus Torvalds * mapping */ 12641da177e4SLinus Torvalds ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, 12651da177e4SLinus Torvalds &capabilities); 12668feae131SDavid Howells if (ret < 0) { 12678feae131SDavid Howells kleave(" = %d [val]", ret); 12681da177e4SLinus Torvalds return ret; 12698feae131SDavid Howells } 12701da177e4SLinus Torvalds 127106aab5a3SDavid Howells /* we ignore the address hint */ 127206aab5a3SDavid Howells addr = 0; 1273f67d9b15SBob Liu len = PAGE_ALIGN(len); 127406aab5a3SDavid Howells 12751da177e4SLinus Torvalds /* we've determined that we can make the mapping, now translate what we 12761da177e4SLinus Torvalds * now know into VMA flags */ 12771da177e4SLinus Torvalds vm_flags = determine_vm_flags(file, prot, flags, capabilities); 12781da177e4SLinus Torvalds 12798feae131SDavid Howells /* we're going to need to record the mapping */ 12808feae131SDavid Howells region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); 12818feae131SDavid Howells if (!region) 12828feae131SDavid Howells goto error_getting_region; 12831da177e4SLinus Torvalds 12848feae131SDavid Howells vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); 12858feae131SDavid Howells if (!vma) 12868feae131SDavid Howells goto error_getting_vma; 12871da177e4SLinus Torvalds 12881e2ae599SDavid Howells region->vm_usage = 1; 12898feae131SDavid Howells region->vm_flags = vm_flags; 12908feae131SDavid Howells region->vm_pgoff = pgoff; 12918feae131SDavid Howells 12925beb4930SRik van Riel INIT_LIST_HEAD(&vma->anon_vma_chain); 12938feae131SDavid Howells vma->vm_flags = vm_flags; 12948feae131SDavid Howells vma->vm_pgoff = pgoff; 12958feae131SDavid Howells 12968feae131SDavid Howells if (file) { 1297cb0942b8SAl Viro region->vm_file = get_file(file); 1298cb0942b8SAl Viro vma->vm_file = get_file(file); 12998feae131SDavid Howells } 13008feae131SDavid Howells 13018feae131SDavid Howells down_write(&nommu_region_sem); 13028feae131SDavid Howells 13038feae131SDavid Howells /* if we want to share, we need to check for regions created by other 13041da177e4SLinus Torvalds * mmap() calls that overlap with our proposed mapping 13058feae131SDavid Howells * - we can only share with a superset match on most regular files 13061da177e4SLinus Torvalds * - shared mappings on character devices and memory backed files are 13071da177e4SLinus Torvalds * permitted to overlap inexactly as far as we are concerned for in 13081da177e4SLinus Torvalds * these cases, sharing is handled in the driver or filesystem rather 13091da177e4SLinus Torvalds * than here 13101da177e4SLinus Torvalds */ 13111da177e4SLinus Torvalds if (vm_flags & VM_MAYSHARE) { 13128feae131SDavid Howells struct vm_region *pregion; 13138feae131SDavid Howells unsigned long pglen, rpglen, pgend, rpgend, start; 13141da177e4SLinus Torvalds 13158feae131SDavid Howells pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 13168feae131SDavid Howells pgend = pgoff + pglen; 1317165b2392SDavid Howells 13188feae131SDavid Howells for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { 13198feae131SDavid Howells pregion = rb_entry(rb, struct vm_region, vm_rb); 13201da177e4SLinus Torvalds 13218feae131SDavid Howells if (!(pregion->vm_flags & VM_MAYSHARE)) 13221da177e4SLinus Torvalds continue; 13231da177e4SLinus Torvalds 13241da177e4SLinus Torvalds /* search for overlapping mappings on the same file */ 1325*496ad9aaSAl Viro if (file_inode(pregion->vm_file) != 1326*496ad9aaSAl Viro file_inode(file)) 13271da177e4SLinus Torvalds continue; 13281da177e4SLinus Torvalds 13298feae131SDavid Howells if (pregion->vm_pgoff >= pgend) 13301da177e4SLinus Torvalds continue; 13311da177e4SLinus Torvalds 13328feae131SDavid Howells rpglen = pregion->vm_end - pregion->vm_start; 13338feae131SDavid Howells rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; 13348feae131SDavid Howells rpgend = pregion->vm_pgoff + rpglen; 13358feae131SDavid Howells if (pgoff >= rpgend) 13361da177e4SLinus Torvalds continue; 13371da177e4SLinus Torvalds 13388feae131SDavid Howells /* handle inexactly overlapping matches between 13398feae131SDavid Howells * mappings */ 13408feae131SDavid Howells if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && 13418feae131SDavid Howells !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { 13428feae131SDavid Howells /* new mapping is not a subset of the region */ 13431da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_DIRECT)) 13441da177e4SLinus Torvalds goto sharing_violation; 13451da177e4SLinus Torvalds continue; 13461da177e4SLinus Torvalds } 13471da177e4SLinus Torvalds 13488feae131SDavid Howells /* we've found a region we can share */ 13491e2ae599SDavid Howells pregion->vm_usage++; 13508feae131SDavid Howells vma->vm_region = pregion; 13518feae131SDavid Howells start = pregion->vm_start; 13528feae131SDavid Howells start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; 13538feae131SDavid Howells vma->vm_start = start; 13548feae131SDavid Howells vma->vm_end = start + len; 13551da177e4SLinus Torvalds 13568feae131SDavid Howells if (pregion->vm_flags & VM_MAPPED_COPY) { 13578feae131SDavid Howells kdebug("share copy"); 13588feae131SDavid Howells vma->vm_flags |= VM_MAPPED_COPY; 13598feae131SDavid Howells } else { 13608feae131SDavid Howells kdebug("share mmap"); 13618feae131SDavid Howells ret = do_mmap_shared_file(vma); 13628feae131SDavid Howells if (ret < 0) { 13638feae131SDavid Howells vma->vm_region = NULL; 13648feae131SDavid Howells vma->vm_start = 0; 13658feae131SDavid Howells vma->vm_end = 0; 13661e2ae599SDavid Howells pregion->vm_usage--; 13678feae131SDavid Howells pregion = NULL; 13688feae131SDavid Howells goto error_just_free; 13691da177e4SLinus Torvalds } 13708feae131SDavid Howells } 13718feae131SDavid Howells fput(region->vm_file); 13728feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 13738feae131SDavid Howells region = pregion; 13748feae131SDavid Howells result = start; 13758feae131SDavid Howells goto share; 13768feae131SDavid Howells } 13771da177e4SLinus Torvalds 13781da177e4SLinus Torvalds /* obtain the address at which to make a shared mapping 13791da177e4SLinus Torvalds * - this is the hook for quasi-memory character devices to 13801da177e4SLinus Torvalds * tell us the location of a shared mapping 13811da177e4SLinus Torvalds */ 1382645d83c5SDavid Howells if (capabilities & BDI_CAP_MAP_DIRECT) { 13831da177e4SLinus Torvalds addr = file->f_op->get_unmapped_area(file, addr, len, 13841da177e4SLinus Torvalds pgoff, flags); 1385bb005a59SNamhyung Kim if (IS_ERR_VALUE(addr)) { 13861da177e4SLinus Torvalds ret = addr; 1387bb005a59SNamhyung Kim if (ret != -ENOSYS) 13888feae131SDavid Howells goto error_just_free; 13891da177e4SLinus Torvalds 13901da177e4SLinus Torvalds /* the driver refused to tell us where to site 13911da177e4SLinus Torvalds * the mapping so we'll have to attempt to copy 13921da177e4SLinus Torvalds * it */ 1393bb005a59SNamhyung Kim ret = -ENODEV; 13941da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_COPY)) 13958feae131SDavid Howells goto error_just_free; 13961da177e4SLinus Torvalds 13971da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 13988feae131SDavid Howells } else { 13998feae131SDavid Howells vma->vm_start = region->vm_start = addr; 14008feae131SDavid Howells vma->vm_end = region->vm_end = addr + len; 14011da177e4SLinus Torvalds } 14021da177e4SLinus Torvalds } 14031da177e4SLinus Torvalds } 14041da177e4SLinus Torvalds 14058feae131SDavid Howells vma->vm_region = region; 14061da177e4SLinus Torvalds 1407645d83c5SDavid Howells /* set up the mapping 1408645d83c5SDavid Howells * - the region is filled in if BDI_CAP_MAP_DIRECT is still set 1409645d83c5SDavid Howells */ 14101da177e4SLinus Torvalds if (file && vma->vm_flags & VM_SHARED) 14118feae131SDavid Howells ret = do_mmap_shared_file(vma); 14121da177e4SLinus Torvalds else 1413645d83c5SDavid Howells ret = do_mmap_private(vma, region, len, capabilities); 14141da177e4SLinus Torvalds if (ret < 0) 1415645d83c5SDavid Howells goto error_just_free; 1416645d83c5SDavid Howells add_nommu_region(region); 14178feae131SDavid Howells 1418ea637639SJie Zhang /* clear anonymous mappings that don't ask for uninitialized data */ 1419ea637639SJie Zhang if (!vma->vm_file && !(flags & MAP_UNINITIALIZED)) 1420ea637639SJie Zhang memset((void *)region->vm_start, 0, 1421ea637639SJie Zhang region->vm_end - region->vm_start); 1422ea637639SJie Zhang 14231da177e4SLinus Torvalds /* okay... we have a mapping; now we have to register it */ 14248feae131SDavid Howells result = vma->vm_start; 14251da177e4SLinus Torvalds 14261da177e4SLinus Torvalds current->mm->total_vm += len >> PAGE_SHIFT; 14271da177e4SLinus Torvalds 14288feae131SDavid Howells share: 14298feae131SDavid Howells add_vma_to_mm(current->mm, vma); 14301da177e4SLinus Torvalds 1431cfe79c00SMike Frysinger /* we flush the region from the icache only when the first executable 1432cfe79c00SMike Frysinger * mapping of it is made */ 1433cfe79c00SMike Frysinger if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { 1434cfe79c00SMike Frysinger flush_icache_range(region->vm_start, region->vm_end); 1435cfe79c00SMike Frysinger region->vm_icache_flushed = true; 1436cfe79c00SMike Frysinger } 14371da177e4SLinus Torvalds 1438cfe79c00SMike Frysinger up_write(&nommu_region_sem); 14391da177e4SLinus Torvalds 14408feae131SDavid Howells kleave(" = %lx", result); 14418feae131SDavid Howells return result; 14421da177e4SLinus Torvalds 14438feae131SDavid Howells error_just_free: 14448feae131SDavid Howells up_write(&nommu_region_sem); 14458feae131SDavid Howells error: 144689a86402SDavid Howells if (region->vm_file) 14478feae131SDavid Howells fput(region->vm_file); 14488feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 144989a86402SDavid Howells if (vma->vm_file) 14508feae131SDavid Howells fput(vma->vm_file); 14518feae131SDavid Howells kmem_cache_free(vm_area_cachep, vma); 14528feae131SDavid Howells kleave(" = %d", ret); 14531da177e4SLinus Torvalds return ret; 14541da177e4SLinus Torvalds 14551da177e4SLinus Torvalds sharing_violation: 14568feae131SDavid Howells up_write(&nommu_region_sem); 14578feae131SDavid Howells printk(KERN_WARNING "Attempt to share mismatched mappings\n"); 14588feae131SDavid Howells ret = -EINVAL; 14598feae131SDavid Howells goto error; 14601da177e4SLinus Torvalds 14611da177e4SLinus Torvalds error_getting_vma: 14628feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 14638feae131SDavid Howells printk(KERN_WARNING "Allocation of vma for %lu byte allocation" 14648feae131SDavid Howells " from process %d failed\n", 14651da177e4SLinus Torvalds len, current->pid); 14667bf02ea2SDavid Rientjes show_free_areas(0); 14671da177e4SLinus Torvalds return -ENOMEM; 14681da177e4SLinus Torvalds 14698feae131SDavid Howells error_getting_region: 14708feae131SDavid Howells printk(KERN_WARNING "Allocation of vm region for %lu byte allocation" 14718feae131SDavid Howells " from process %d failed\n", 14721da177e4SLinus Torvalds len, current->pid); 14737bf02ea2SDavid Rientjes show_free_areas(0); 14741da177e4SLinus Torvalds return -ENOMEM; 14751da177e4SLinus Torvalds } 14766be5ceb0SLinus Torvalds 147766f0dc48SHugh Dickins SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 147866f0dc48SHugh Dickins unsigned long, prot, unsigned long, flags, 147966f0dc48SHugh Dickins unsigned long, fd, unsigned long, pgoff) 148066f0dc48SHugh Dickins { 148166f0dc48SHugh Dickins struct file *file = NULL; 148266f0dc48SHugh Dickins unsigned long retval = -EBADF; 148366f0dc48SHugh Dickins 1484120a795dSAl Viro audit_mmap_fd(fd, flags); 148566f0dc48SHugh Dickins if (!(flags & MAP_ANONYMOUS)) { 148666f0dc48SHugh Dickins file = fget(fd); 148766f0dc48SHugh Dickins if (!file) 148866f0dc48SHugh Dickins goto out; 148966f0dc48SHugh Dickins } 149066f0dc48SHugh Dickins 149166f0dc48SHugh Dickins flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); 149266f0dc48SHugh Dickins 1493ad1ed293SGreg Ungerer retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); 149466f0dc48SHugh Dickins 149566f0dc48SHugh Dickins if (file) 149666f0dc48SHugh Dickins fput(file); 149766f0dc48SHugh Dickins out: 149866f0dc48SHugh Dickins return retval; 149966f0dc48SHugh Dickins } 150066f0dc48SHugh Dickins 1501a4679373SChristoph Hellwig #ifdef __ARCH_WANT_SYS_OLD_MMAP 1502a4679373SChristoph Hellwig struct mmap_arg_struct { 1503a4679373SChristoph Hellwig unsigned long addr; 1504a4679373SChristoph Hellwig unsigned long len; 1505a4679373SChristoph Hellwig unsigned long prot; 1506a4679373SChristoph Hellwig unsigned long flags; 1507a4679373SChristoph Hellwig unsigned long fd; 1508a4679373SChristoph Hellwig unsigned long offset; 1509a4679373SChristoph Hellwig }; 1510a4679373SChristoph Hellwig 1511a4679373SChristoph Hellwig SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) 1512a4679373SChristoph Hellwig { 1513a4679373SChristoph Hellwig struct mmap_arg_struct a; 1514a4679373SChristoph Hellwig 1515a4679373SChristoph Hellwig if (copy_from_user(&a, arg, sizeof(a))) 1516a4679373SChristoph Hellwig return -EFAULT; 1517a4679373SChristoph Hellwig if (a.offset & ~PAGE_MASK) 1518a4679373SChristoph Hellwig return -EINVAL; 1519a4679373SChristoph Hellwig 1520a4679373SChristoph Hellwig return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, 1521a4679373SChristoph Hellwig a.offset >> PAGE_SHIFT); 1522a4679373SChristoph Hellwig } 1523a4679373SChristoph Hellwig #endif /* __ARCH_WANT_SYS_OLD_MMAP */ 1524a4679373SChristoph Hellwig 15251da177e4SLinus Torvalds /* 15268feae131SDavid Howells * split a vma into two pieces at address 'addr', a new vma is allocated either 15278feae131SDavid Howells * for the first part or the tail. 15281da177e4SLinus Torvalds */ 15298feae131SDavid Howells int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 15308feae131SDavid Howells unsigned long addr, int new_below) 15311da177e4SLinus Torvalds { 15328feae131SDavid Howells struct vm_area_struct *new; 15338feae131SDavid Howells struct vm_region *region; 15348feae131SDavid Howells unsigned long npages; 15351da177e4SLinus Torvalds 15368feae131SDavid Howells kenter(""); 15371da177e4SLinus Torvalds 1538779c1023SDavid Howells /* we're only permitted to split anonymous regions (these should have 1539779c1023SDavid Howells * only a single usage on the region) */ 1540779c1023SDavid Howells if (vma->vm_file) 15418feae131SDavid Howells return -ENOMEM; 15421da177e4SLinus Torvalds 15438feae131SDavid Howells if (mm->map_count >= sysctl_max_map_count) 15448feae131SDavid Howells return -ENOMEM; 15451da177e4SLinus Torvalds 15468feae131SDavid Howells region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); 15478feae131SDavid Howells if (!region) 15488feae131SDavid Howells return -ENOMEM; 15498feae131SDavid Howells 15508feae131SDavid Howells new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); 15518feae131SDavid Howells if (!new) { 15528feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 15538feae131SDavid Howells return -ENOMEM; 15541da177e4SLinus Torvalds } 15551da177e4SLinus Torvalds 15568feae131SDavid Howells /* most fields are the same, copy all, and then fixup */ 15578feae131SDavid Howells *new = *vma; 15588feae131SDavid Howells *region = *vma->vm_region; 15598feae131SDavid Howells new->vm_region = region; 15608feae131SDavid Howells 15618feae131SDavid Howells npages = (addr - vma->vm_start) >> PAGE_SHIFT; 15628feae131SDavid Howells 15638feae131SDavid Howells if (new_below) { 1564dd8632a1SPaul Mundt region->vm_top = region->vm_end = new->vm_end = addr; 15658feae131SDavid Howells } else { 15668feae131SDavid Howells region->vm_start = new->vm_start = addr; 15678feae131SDavid Howells region->vm_pgoff = new->vm_pgoff += npages; 15681da177e4SLinus Torvalds } 15698feae131SDavid Howells 15708feae131SDavid Howells if (new->vm_ops && new->vm_ops->open) 15718feae131SDavid Howells new->vm_ops->open(new); 15728feae131SDavid Howells 15738feae131SDavid Howells delete_vma_from_mm(vma); 15748feae131SDavid Howells down_write(&nommu_region_sem); 15758feae131SDavid Howells delete_nommu_region(vma->vm_region); 15768feae131SDavid Howells if (new_below) { 15778feae131SDavid Howells vma->vm_region->vm_start = vma->vm_start = addr; 15788feae131SDavid Howells vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; 15798feae131SDavid Howells } else { 15808feae131SDavid Howells vma->vm_region->vm_end = vma->vm_end = addr; 1581dd8632a1SPaul Mundt vma->vm_region->vm_top = addr; 15828feae131SDavid Howells } 15838feae131SDavid Howells add_nommu_region(vma->vm_region); 15848feae131SDavid Howells add_nommu_region(new->vm_region); 15858feae131SDavid Howells up_write(&nommu_region_sem); 15868feae131SDavid Howells add_vma_to_mm(mm, vma); 15878feae131SDavid Howells add_vma_to_mm(mm, new); 15888feae131SDavid Howells return 0; 15898feae131SDavid Howells } 15908feae131SDavid Howells 15918feae131SDavid Howells /* 15928feae131SDavid Howells * shrink a VMA by removing the specified chunk from either the beginning or 15938feae131SDavid Howells * the end 15948feae131SDavid Howells */ 15958feae131SDavid Howells static int shrink_vma(struct mm_struct *mm, 15968feae131SDavid Howells struct vm_area_struct *vma, 15978feae131SDavid Howells unsigned long from, unsigned long to) 15988feae131SDavid Howells { 15998feae131SDavid Howells struct vm_region *region; 16008feae131SDavid Howells 16018feae131SDavid Howells kenter(""); 16028feae131SDavid Howells 16038feae131SDavid Howells /* adjust the VMA's pointers, which may reposition it in the MM's tree 16048feae131SDavid Howells * and list */ 16058feae131SDavid Howells delete_vma_from_mm(vma); 16068feae131SDavid Howells if (from > vma->vm_start) 16078feae131SDavid Howells vma->vm_end = from; 16088feae131SDavid Howells else 16098feae131SDavid Howells vma->vm_start = to; 16108feae131SDavid Howells add_vma_to_mm(mm, vma); 16118feae131SDavid Howells 16128feae131SDavid Howells /* cut the backing region down to size */ 16138feae131SDavid Howells region = vma->vm_region; 16141e2ae599SDavid Howells BUG_ON(region->vm_usage != 1); 16158feae131SDavid Howells 16168feae131SDavid Howells down_write(&nommu_region_sem); 16178feae131SDavid Howells delete_nommu_region(region); 1618dd8632a1SPaul Mundt if (from > region->vm_start) { 1619dd8632a1SPaul Mundt to = region->vm_top; 1620dd8632a1SPaul Mundt region->vm_top = region->vm_end = from; 1621dd8632a1SPaul Mundt } else { 16228feae131SDavid Howells region->vm_start = to; 1623dd8632a1SPaul Mundt } 16248feae131SDavid Howells add_nommu_region(region); 16258feae131SDavid Howells up_write(&nommu_region_sem); 16268feae131SDavid Howells 16278feae131SDavid Howells free_page_series(from, to); 16288feae131SDavid Howells return 0; 16291da177e4SLinus Torvalds } 16301da177e4SLinus Torvalds 16313034097aSDavid Howells /* 16323034097aSDavid Howells * release a mapping 16338feae131SDavid Howells * - under NOMMU conditions the chunk to be unmapped must be backed by a single 16348feae131SDavid Howells * VMA, though it need not cover the whole VMA 16353034097aSDavid Howells */ 16368feae131SDavid Howells int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) 16371da177e4SLinus Torvalds { 16388feae131SDavid Howells struct vm_area_struct *vma; 1639f67d9b15SBob Liu unsigned long end; 16408feae131SDavid Howells int ret; 16411da177e4SLinus Torvalds 16428feae131SDavid Howells kenter(",%lx,%zx", start, len); 16431da177e4SLinus Torvalds 1644f67d9b15SBob Liu len = PAGE_ALIGN(len); 16458feae131SDavid Howells if (len == 0) 16461da177e4SLinus Torvalds return -EINVAL; 16471da177e4SLinus Torvalds 1648f67d9b15SBob Liu end = start + len; 1649f67d9b15SBob Liu 16508feae131SDavid Howells /* find the first potentially overlapping VMA */ 16518feae131SDavid Howells vma = find_vma(mm, start); 16528feae131SDavid Howells if (!vma) { 165333e5d769SDavid Howells static int limit = 0; 165433e5d769SDavid Howells if (limit < 5) { 16558feae131SDavid Howells printk(KERN_WARNING 165633e5d769SDavid Howells "munmap of memory not mmapped by process %d" 165733e5d769SDavid Howells " (%s): 0x%lx-0x%lx\n", 165833e5d769SDavid Howells current->pid, current->comm, 165933e5d769SDavid Howells start, start + len - 1); 166033e5d769SDavid Howells limit++; 166133e5d769SDavid Howells } 16628feae131SDavid Howells return -EINVAL; 16638feae131SDavid Howells } 16641da177e4SLinus Torvalds 16658feae131SDavid Howells /* we're allowed to split an anonymous VMA but not a file-backed one */ 16668feae131SDavid Howells if (vma->vm_file) { 16678feae131SDavid Howells do { 16688feae131SDavid Howells if (start > vma->vm_start) { 16698feae131SDavid Howells kleave(" = -EINVAL [miss]"); 16708feae131SDavid Howells return -EINVAL; 16718feae131SDavid Howells } 16728feae131SDavid Howells if (end == vma->vm_end) 16738feae131SDavid Howells goto erase_whole_vma; 1674d75a310cSNamhyung Kim vma = vma->vm_next; 1675d75a310cSNamhyung Kim } while (vma); 16768feae131SDavid Howells kleave(" = -EINVAL [split file]"); 16778feae131SDavid Howells return -EINVAL; 16788feae131SDavid Howells } else { 16798feae131SDavid Howells /* the chunk must be a subset of the VMA found */ 16808feae131SDavid Howells if (start == vma->vm_start && end == vma->vm_end) 16818feae131SDavid Howells goto erase_whole_vma; 16828feae131SDavid Howells if (start < vma->vm_start || end > vma->vm_end) { 16838feae131SDavid Howells kleave(" = -EINVAL [superset]"); 16848feae131SDavid Howells return -EINVAL; 16858feae131SDavid Howells } 16868feae131SDavid Howells if (start & ~PAGE_MASK) { 16878feae131SDavid Howells kleave(" = -EINVAL [unaligned start]"); 16888feae131SDavid Howells return -EINVAL; 16898feae131SDavid Howells } 16908feae131SDavid Howells if (end != vma->vm_end && end & ~PAGE_MASK) { 16918feae131SDavid Howells kleave(" = -EINVAL [unaligned split]"); 16928feae131SDavid Howells return -EINVAL; 16938feae131SDavid Howells } 16948feae131SDavid Howells if (start != vma->vm_start && end != vma->vm_end) { 16958feae131SDavid Howells ret = split_vma(mm, vma, start, 1); 16968feae131SDavid Howells if (ret < 0) { 16978feae131SDavid Howells kleave(" = %d [split]", ret); 16988feae131SDavid Howells return ret; 16998feae131SDavid Howells } 17008feae131SDavid Howells } 17018feae131SDavid Howells return shrink_vma(mm, vma, start, end); 17028feae131SDavid Howells } 17031da177e4SLinus Torvalds 17048feae131SDavid Howells erase_whole_vma: 17058feae131SDavid Howells delete_vma_from_mm(vma); 17068feae131SDavid Howells delete_vma(mm, vma); 17078feae131SDavid Howells kleave(" = 0"); 17081da177e4SLinus Torvalds return 0; 17091da177e4SLinus Torvalds } 1710b5073173SPaul Mundt EXPORT_SYMBOL(do_munmap); 17111da177e4SLinus Torvalds 1712bfce281cSAl Viro int vm_munmap(unsigned long addr, size_t len) 17133034097aSDavid Howells { 1714bfce281cSAl Viro struct mm_struct *mm = current->mm; 17153034097aSDavid Howells int ret; 17163034097aSDavid Howells 17173034097aSDavid Howells down_write(&mm->mmap_sem); 17183034097aSDavid Howells ret = do_munmap(mm, addr, len); 17193034097aSDavid Howells up_write(&mm->mmap_sem); 17203034097aSDavid Howells return ret; 17213034097aSDavid Howells } 1722a46ef99dSLinus Torvalds EXPORT_SYMBOL(vm_munmap); 1723a46ef99dSLinus Torvalds 1724a46ef99dSLinus Torvalds SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) 1725a46ef99dSLinus Torvalds { 1726bfce281cSAl Viro return vm_munmap(addr, len); 1727a46ef99dSLinus Torvalds } 17283034097aSDavid Howells 17293034097aSDavid Howells /* 17308feae131SDavid Howells * release all the mappings made in a process's VM space 17313034097aSDavid Howells */ 17321da177e4SLinus Torvalds void exit_mmap(struct mm_struct *mm) 17331da177e4SLinus Torvalds { 17348feae131SDavid Howells struct vm_area_struct *vma; 17351da177e4SLinus Torvalds 17368feae131SDavid Howells if (!mm) 17378feae131SDavid Howells return; 17388feae131SDavid Howells 17398feae131SDavid Howells kenter(""); 17401da177e4SLinus Torvalds 17411da177e4SLinus Torvalds mm->total_vm = 0; 17421da177e4SLinus Torvalds 17438feae131SDavid Howells while ((vma = mm->mmap)) { 17448feae131SDavid Howells mm->mmap = vma->vm_next; 17458feae131SDavid Howells delete_vma_from_mm(vma); 17468feae131SDavid Howells delete_vma(mm, vma); 174704c34961SSteven J. Magnani cond_resched(); 17481da177e4SLinus Torvalds } 17491da177e4SLinus Torvalds 17508feae131SDavid Howells kleave(""); 17511da177e4SLinus Torvalds } 17521da177e4SLinus Torvalds 1753e4eb1ff6SLinus Torvalds unsigned long vm_brk(unsigned long addr, unsigned long len) 17541da177e4SLinus Torvalds { 17551da177e4SLinus Torvalds return -ENOMEM; 17561da177e4SLinus Torvalds } 17571da177e4SLinus Torvalds 17581da177e4SLinus Torvalds /* 17596fa5f80bSDavid Howells * expand (or shrink) an existing mapping, potentially moving it at the same 17606fa5f80bSDavid Howells * time (controlled by the MREMAP_MAYMOVE flag and available VM space) 17611da177e4SLinus Torvalds * 17626fa5f80bSDavid Howells * under NOMMU conditions, we only permit changing a mapping's size, and only 17638feae131SDavid Howells * as long as it stays within the region allocated by do_mmap_private() and the 17648feae131SDavid Howells * block is not shareable 17651da177e4SLinus Torvalds * 17666fa5f80bSDavid Howells * MREMAP_FIXED is not supported under NOMMU conditions 17671da177e4SLinus Torvalds */ 17681da177e4SLinus Torvalds unsigned long do_mremap(unsigned long addr, 17691da177e4SLinus Torvalds unsigned long old_len, unsigned long new_len, 17701da177e4SLinus Torvalds unsigned long flags, unsigned long new_addr) 17711da177e4SLinus Torvalds { 17726fa5f80bSDavid Howells struct vm_area_struct *vma; 17731da177e4SLinus Torvalds 17741da177e4SLinus Torvalds /* insanity checks first */ 1775f67d9b15SBob Liu old_len = PAGE_ALIGN(old_len); 1776f67d9b15SBob Liu new_len = PAGE_ALIGN(new_len); 17778feae131SDavid Howells if (old_len == 0 || new_len == 0) 17781da177e4SLinus Torvalds return (unsigned long) -EINVAL; 17791da177e4SLinus Torvalds 17808feae131SDavid Howells if (addr & ~PAGE_MASK) 17818feae131SDavid Howells return -EINVAL; 17828feae131SDavid Howells 17831da177e4SLinus Torvalds if (flags & MREMAP_FIXED && new_addr != addr) 17841da177e4SLinus Torvalds return (unsigned long) -EINVAL; 17851da177e4SLinus Torvalds 17868feae131SDavid Howells vma = find_vma_exact(current->mm, addr, old_len); 17876fa5f80bSDavid Howells if (!vma) 17881da177e4SLinus Torvalds return (unsigned long) -EINVAL; 17891da177e4SLinus Torvalds 17906fa5f80bSDavid Howells if (vma->vm_end != vma->vm_start + old_len) 17911da177e4SLinus Torvalds return (unsigned long) -EFAULT; 17921da177e4SLinus Torvalds 17936fa5f80bSDavid Howells if (vma->vm_flags & VM_MAYSHARE) 17941da177e4SLinus Torvalds return (unsigned long) -EPERM; 17951da177e4SLinus Torvalds 17968feae131SDavid Howells if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) 17971da177e4SLinus Torvalds return (unsigned long) -ENOMEM; 17981da177e4SLinus Torvalds 17991da177e4SLinus Torvalds /* all checks complete - do it */ 18006fa5f80bSDavid Howells vma->vm_end = vma->vm_start + new_len; 18016fa5f80bSDavid Howells return vma->vm_start; 18026fa5f80bSDavid Howells } 1803b5073173SPaul Mundt EXPORT_SYMBOL(do_mremap); 18046fa5f80bSDavid Howells 18056a6160a7SHeiko Carstens SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 18066a6160a7SHeiko Carstens unsigned long, new_len, unsigned long, flags, 18076a6160a7SHeiko Carstens unsigned long, new_addr) 18086fa5f80bSDavid Howells { 18096fa5f80bSDavid Howells unsigned long ret; 18106fa5f80bSDavid Howells 18116fa5f80bSDavid Howells down_write(¤t->mm->mmap_sem); 18126fa5f80bSDavid Howells ret = do_mremap(addr, old_len, new_len, flags, new_addr); 18136fa5f80bSDavid Howells up_write(¤t->mm->mmap_sem); 18146fa5f80bSDavid Howells return ret; 18151da177e4SLinus Torvalds } 18161da177e4SLinus Torvalds 18176aab341eSLinus Torvalds struct page *follow_page(struct vm_area_struct *vma, unsigned long address, 1818deceb6cdSHugh Dickins unsigned int foll_flags) 18191da177e4SLinus Torvalds { 18201da177e4SLinus Torvalds return NULL; 18211da177e4SLinus Torvalds } 18221da177e4SLinus Torvalds 18238f3b1327SBob Liu int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 18248f3b1327SBob Liu unsigned long pfn, unsigned long size, pgprot_t prot) 18251da177e4SLinus Torvalds { 18268f3b1327SBob Liu if (addr != (pfn << PAGE_SHIFT)) 18278f3b1327SBob Liu return -EINVAL; 18288f3b1327SBob Liu 1829314e51b9SKonstantin Khlebnikov vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 183066aa2b4bSGreg Ungerer return 0; 18311da177e4SLinus Torvalds } 183222c4af40SLuke Yang EXPORT_SYMBOL(remap_pfn_range); 18331da177e4SLinus Torvalds 1834f905bc44SPaul Mundt int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 1835f905bc44SPaul Mundt unsigned long pgoff) 1836f905bc44SPaul Mundt { 1837f905bc44SPaul Mundt unsigned int size = vma->vm_end - vma->vm_start; 1838f905bc44SPaul Mundt 1839f905bc44SPaul Mundt if (!(vma->vm_flags & VM_USERMAP)) 1840f905bc44SPaul Mundt return -EINVAL; 1841f905bc44SPaul Mundt 1842f905bc44SPaul Mundt vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); 1843f905bc44SPaul Mundt vma->vm_end = vma->vm_start + size; 1844f905bc44SPaul Mundt 1845f905bc44SPaul Mundt return 0; 1846f905bc44SPaul Mundt } 1847f905bc44SPaul Mundt EXPORT_SYMBOL(remap_vmalloc_range); 1848f905bc44SPaul Mundt 18491da177e4SLinus Torvalds unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, 18501da177e4SLinus Torvalds unsigned long len, unsigned long pgoff, unsigned long flags) 18511da177e4SLinus Torvalds { 18521da177e4SLinus Torvalds return -ENOMEM; 18531da177e4SLinus Torvalds } 18541da177e4SLinus Torvalds 18551363c3cdSWolfgang Wander void arch_unmap_area(struct mm_struct *mm, unsigned long addr) 18561da177e4SLinus Torvalds { 18571da177e4SLinus Torvalds } 18581da177e4SLinus Torvalds 18591da177e4SLinus Torvalds void unmap_mapping_range(struct address_space *mapping, 18601da177e4SLinus Torvalds loff_t const holebegin, loff_t const holelen, 18611da177e4SLinus Torvalds int even_cows) 18621da177e4SLinus Torvalds { 18631da177e4SLinus Torvalds } 186422c4af40SLuke Yang EXPORT_SYMBOL(unmap_mapping_range); 18651da177e4SLinus Torvalds 18661da177e4SLinus Torvalds /* 18671da177e4SLinus Torvalds * Check that a process has enough memory to allocate a new virtual 18681da177e4SLinus Torvalds * mapping. 0 means there is enough memory for the allocation to 18691da177e4SLinus Torvalds * succeed and -ENOMEM implies there is not. 18701da177e4SLinus Torvalds * 18711da177e4SLinus Torvalds * We currently support three overcommit policies, which are set via the 18721da177e4SLinus Torvalds * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting 18731da177e4SLinus Torvalds * 18741da177e4SLinus Torvalds * Strict overcommit modes added 2002 Feb 26 by Alan Cox. 18751da177e4SLinus Torvalds * Additional code 2002 Jul 20 by Robert Love. 18761da177e4SLinus Torvalds * 18771da177e4SLinus Torvalds * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. 18781da177e4SLinus Torvalds * 18791da177e4SLinus Torvalds * Note this is a helper function intended to be used by LSMs which 18801da177e4SLinus Torvalds * wish to use this logic. 18811da177e4SLinus Torvalds */ 188234b4e4aaSAlan Cox int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) 18831da177e4SLinus Torvalds { 18841da177e4SLinus Torvalds unsigned long free, allowed; 18851da177e4SLinus Torvalds 18861da177e4SLinus Torvalds vm_acct_memory(pages); 18871da177e4SLinus Torvalds 18881da177e4SLinus Torvalds /* 18891da177e4SLinus Torvalds * Sometimes we want to use more memory than we have 18901da177e4SLinus Torvalds */ 18911da177e4SLinus Torvalds if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) 18921da177e4SLinus Torvalds return 0; 18931da177e4SLinus Torvalds 18941da177e4SLinus Torvalds if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { 1895c15bef30SDmitry Fink free = global_page_state(NR_FREE_PAGES); 1896c15bef30SDmitry Fink free += global_page_state(NR_FILE_PAGES); 18971da177e4SLinus Torvalds 1898c15bef30SDmitry Fink /* 1899c15bef30SDmitry Fink * shmem pages shouldn't be counted as free in this 1900c15bef30SDmitry Fink * case, they can't be purged, only swapped out, and 1901c15bef30SDmitry Fink * that won't affect the overall amount of available 1902c15bef30SDmitry Fink * memory in the system. 1903c15bef30SDmitry Fink */ 1904c15bef30SDmitry Fink free -= global_page_state(NR_SHMEM); 1905c15bef30SDmitry Fink 19061da177e4SLinus Torvalds free += nr_swap_pages; 19071da177e4SLinus Torvalds 19081da177e4SLinus Torvalds /* 19091da177e4SLinus Torvalds * Any slabs which are created with the 19101da177e4SLinus Torvalds * SLAB_RECLAIM_ACCOUNT flag claim to have contents 19111da177e4SLinus Torvalds * which are reclaimable, under pressure. The dentry 19121da177e4SLinus Torvalds * cache and most inode caches should fall into this 19131da177e4SLinus Torvalds */ 1914972d1a7bSChristoph Lameter free += global_page_state(NR_SLAB_RECLAIMABLE); 19151da177e4SLinus Torvalds 19161da177e4SLinus Torvalds /* 1917c15bef30SDmitry Fink * Leave reserved pages. The pages are not for anonymous pages. 1918c15bef30SDmitry Fink */ 1919c15bef30SDmitry Fink if (free <= totalreserve_pages) 1920c15bef30SDmitry Fink goto error; 1921c15bef30SDmitry Fink else 1922c15bef30SDmitry Fink free -= totalreserve_pages; 1923c15bef30SDmitry Fink 1924c15bef30SDmitry Fink /* 19251da177e4SLinus Torvalds * Leave the last 3% for root 19261da177e4SLinus Torvalds */ 19271da177e4SLinus Torvalds if (!cap_sys_admin) 19281da177e4SLinus Torvalds free -= free / 32; 19291da177e4SLinus Torvalds 19301da177e4SLinus Torvalds if (free > pages) 19311da177e4SLinus Torvalds return 0; 19321da177e4SLinus Torvalds 1933d5ddc79bSHideo AOKI goto error; 19341da177e4SLinus Torvalds } 19351da177e4SLinus Torvalds 19361da177e4SLinus Torvalds allowed = totalram_pages * sysctl_overcommit_ratio / 100; 19371da177e4SLinus Torvalds /* 19381da177e4SLinus Torvalds * Leave the last 3% for root 19391da177e4SLinus Torvalds */ 19401da177e4SLinus Torvalds if (!cap_sys_admin) 19411da177e4SLinus Torvalds allowed -= allowed / 32; 19421da177e4SLinus Torvalds allowed += total_swap_pages; 19431da177e4SLinus Torvalds 19441da177e4SLinus Torvalds /* Don't let a single process grow too big: 19451da177e4SLinus Torvalds leave 3% of the size of this process for other processes */ 1946731572d3SAlan Cox if (mm) 1947731572d3SAlan Cox allowed -= mm->total_vm / 32; 19481da177e4SLinus Torvalds 194900a62ce9SKOSAKI Motohiro if (percpu_counter_read_positive(&vm_committed_as) < allowed) 19501da177e4SLinus Torvalds return 0; 195100a62ce9SKOSAKI Motohiro 1952d5ddc79bSHideo AOKI error: 19531da177e4SLinus Torvalds vm_unacct_memory(pages); 19541da177e4SLinus Torvalds 19551da177e4SLinus Torvalds return -ENOMEM; 19561da177e4SLinus Torvalds } 19571da177e4SLinus Torvalds 1958cae5d390SStephen Wilson int in_gate_area_no_mm(unsigned long addr) 19591da177e4SLinus Torvalds { 19601da177e4SLinus Torvalds return 0; 19611da177e4SLinus Torvalds } 1962b0e15190SDavid Howells 1963d0217ac0SNick Piggin int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 1964b0e15190SDavid Howells { 1965b0e15190SDavid Howells BUG(); 1966d0217ac0SNick Piggin return 0; 1967b0e15190SDavid Howells } 1968b5073173SPaul Mundt EXPORT_SYMBOL(filemap_fault); 19690ec76a11SDavid Howells 19700b173bc4SKonstantin Khlebnikov int generic_file_remap_pages(struct vm_area_struct *vma, unsigned long addr, 19710b173bc4SKonstantin Khlebnikov unsigned long size, pgoff_t pgoff) 19720b173bc4SKonstantin Khlebnikov { 19730b173bc4SKonstantin Khlebnikov BUG(); 19740b173bc4SKonstantin Khlebnikov return 0; 19750b173bc4SKonstantin Khlebnikov } 19760b173bc4SKonstantin Khlebnikov EXPORT_SYMBOL(generic_file_remap_pages); 19770b173bc4SKonstantin Khlebnikov 1978f55f199bSMike Frysinger static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, 1979f55f199bSMike Frysinger unsigned long addr, void *buf, int len, int write) 19800ec76a11SDavid Howells { 19810ec76a11SDavid Howells struct vm_area_struct *vma; 19820ec76a11SDavid Howells 19830ec76a11SDavid Howells down_read(&mm->mmap_sem); 19840ec76a11SDavid Howells 19850ec76a11SDavid Howells /* the access must start within one of the target process's mappings */ 19860159b141SDavid Howells vma = find_vma(mm, addr); 19870159b141SDavid Howells if (vma) { 19880ec76a11SDavid Howells /* don't overrun this mapping */ 19890ec76a11SDavid Howells if (addr + len >= vma->vm_end) 19900ec76a11SDavid Howells len = vma->vm_end - addr; 19910ec76a11SDavid Howells 19920ec76a11SDavid Howells /* only read or write mappings where it is permitted */ 1993d00c7b99SDavid Howells if (write && vma->vm_flags & VM_MAYWRITE) 19947959722bSJie Zhang copy_to_user_page(vma, NULL, addr, 19957959722bSJie Zhang (void *) addr, buf, len); 1996d00c7b99SDavid Howells else if (!write && vma->vm_flags & VM_MAYREAD) 19977959722bSJie Zhang copy_from_user_page(vma, NULL, addr, 19987959722bSJie Zhang buf, (void *) addr, len); 19990ec76a11SDavid Howells else 20000ec76a11SDavid Howells len = 0; 20010ec76a11SDavid Howells } else { 20020ec76a11SDavid Howells len = 0; 20030ec76a11SDavid Howells } 20040ec76a11SDavid Howells 20050ec76a11SDavid Howells up_read(&mm->mmap_sem); 2006f55f199bSMike Frysinger 2007f55f199bSMike Frysinger return len; 2008f55f199bSMike Frysinger } 2009f55f199bSMike Frysinger 2010f55f199bSMike Frysinger /** 2011f55f199bSMike Frysinger * @access_remote_vm - access another process' address space 2012f55f199bSMike Frysinger * @mm: the mm_struct of the target address space 2013f55f199bSMike Frysinger * @addr: start address to access 2014f55f199bSMike Frysinger * @buf: source or destination buffer 2015f55f199bSMike Frysinger * @len: number of bytes to transfer 2016f55f199bSMike Frysinger * @write: whether the access is a write 2017f55f199bSMike Frysinger * 2018f55f199bSMike Frysinger * The caller must hold a reference on @mm. 2019f55f199bSMike Frysinger */ 2020f55f199bSMike Frysinger int access_remote_vm(struct mm_struct *mm, unsigned long addr, 2021f55f199bSMike Frysinger void *buf, int len, int write) 2022f55f199bSMike Frysinger { 2023f55f199bSMike Frysinger return __access_remote_vm(NULL, mm, addr, buf, len, write); 2024f55f199bSMike Frysinger } 2025f55f199bSMike Frysinger 2026f55f199bSMike Frysinger /* 2027f55f199bSMike Frysinger * Access another process' address space. 2028f55f199bSMike Frysinger * - source/target buffer must be kernel space 2029f55f199bSMike Frysinger */ 2030f55f199bSMike Frysinger int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) 2031f55f199bSMike Frysinger { 2032f55f199bSMike Frysinger struct mm_struct *mm; 2033f55f199bSMike Frysinger 2034f55f199bSMike Frysinger if (addr + len < addr) 2035f55f199bSMike Frysinger return 0; 2036f55f199bSMike Frysinger 2037f55f199bSMike Frysinger mm = get_task_mm(tsk); 2038f55f199bSMike Frysinger if (!mm) 2039f55f199bSMike Frysinger return 0; 2040f55f199bSMike Frysinger 2041f55f199bSMike Frysinger len = __access_remote_vm(tsk, mm, addr, buf, len, write); 2042f55f199bSMike Frysinger 20430ec76a11SDavid Howells mmput(mm); 20440ec76a11SDavid Howells return len; 20450ec76a11SDavid Howells } 20467e660872SDavid Howells 20477e660872SDavid Howells /** 20487e660872SDavid Howells * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode 20497e660872SDavid Howells * @inode: The inode to check 20507e660872SDavid Howells * @size: The current filesize of the inode 20517e660872SDavid Howells * @newsize: The proposed filesize of the inode 20527e660872SDavid Howells * 20537e660872SDavid Howells * Check the shared mappings on an inode on behalf of a shrinking truncate to 20547e660872SDavid Howells * make sure that that any outstanding VMAs aren't broken and then shrink the 20557e660872SDavid Howells * vm_regions that extend that beyond so that do_mmap_pgoff() doesn't 20567e660872SDavid Howells * automatically grant mappings that are too large. 20577e660872SDavid Howells */ 20587e660872SDavid Howells int nommu_shrink_inode_mappings(struct inode *inode, size_t size, 20597e660872SDavid Howells size_t newsize) 20607e660872SDavid Howells { 20617e660872SDavid Howells struct vm_area_struct *vma; 20627e660872SDavid Howells struct vm_region *region; 20637e660872SDavid Howells pgoff_t low, high; 20647e660872SDavid Howells size_t r_size, r_top; 20657e660872SDavid Howells 20667e660872SDavid Howells low = newsize >> PAGE_SHIFT; 20677e660872SDavid Howells high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 20687e660872SDavid Howells 20697e660872SDavid Howells down_write(&nommu_region_sem); 2070918e556eSDavid Howells mutex_lock(&inode->i_mapping->i_mmap_mutex); 20717e660872SDavid Howells 20727e660872SDavid Howells /* search for VMAs that fall within the dead zone */ 20736b2dbba8SMichel Lespinasse vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) { 20747e660872SDavid Howells /* found one - only interested if it's shared out of the page 20757e660872SDavid Howells * cache */ 20767e660872SDavid Howells if (vma->vm_flags & VM_SHARED) { 2077918e556eSDavid Howells mutex_unlock(&inode->i_mapping->i_mmap_mutex); 20787e660872SDavid Howells up_write(&nommu_region_sem); 20797e660872SDavid Howells return -ETXTBSY; /* not quite true, but near enough */ 20807e660872SDavid Howells } 20817e660872SDavid Howells } 20827e660872SDavid Howells 20837e660872SDavid Howells /* reduce any regions that overlap the dead zone - if in existence, 20847e660872SDavid Howells * these will be pointed to by VMAs that don't overlap the dead zone 20857e660872SDavid Howells * 20867e660872SDavid Howells * we don't check for any regions that start beyond the EOF as there 20877e660872SDavid Howells * shouldn't be any 20887e660872SDavid Howells */ 20896b2dbba8SMichel Lespinasse vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 20907e660872SDavid Howells 0, ULONG_MAX) { 20917e660872SDavid Howells if (!(vma->vm_flags & VM_SHARED)) 20927e660872SDavid Howells continue; 20937e660872SDavid Howells 20947e660872SDavid Howells region = vma->vm_region; 20957e660872SDavid Howells r_size = region->vm_top - region->vm_start; 20967e660872SDavid Howells r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; 20977e660872SDavid Howells 20987e660872SDavid Howells if (r_top > newsize) { 20997e660872SDavid Howells region->vm_top -= r_top - newsize; 21007e660872SDavid Howells if (region->vm_end > region->vm_top) 21017e660872SDavid Howells region->vm_end = region->vm_top; 21027e660872SDavid Howells } 21037e660872SDavid Howells } 21047e660872SDavid Howells 2105918e556eSDavid Howells mutex_unlock(&inode->i_mapping->i_mmap_mutex); 21067e660872SDavid Howells up_write(&nommu_region_sem); 21077e660872SDavid Howells return 0; 21087e660872SDavid Howells } 2109