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 16f2b8544fSDavid Howells #include <linux/module.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> 25fa8e26ccSRoland McGrath #include <linux/tracehook.h> 261da177e4SLinus Torvalds #include <linux/blkdev.h> 271da177e4SLinus Torvalds #include <linux/backing-dev.h> 281da177e4SLinus Torvalds #include <linux/mount.h> 291da177e4SLinus Torvalds #include <linux/personality.h> 301da177e4SLinus Torvalds #include <linux/security.h> 311da177e4SLinus Torvalds #include <linux/syscalls.h> 32120a795dSAl Viro #include <linux/audit.h> 331da177e4SLinus Torvalds 341da177e4SLinus Torvalds #include <asm/uaccess.h> 351da177e4SLinus Torvalds #include <asm/tlb.h> 361da177e4SLinus Torvalds #include <asm/tlbflush.h> 37eb8cdec4SBernd Schmidt #include <asm/mmu_context.h> 388feae131SDavid Howells #include "internal.h" 398feae131SDavid Howells 408feae131SDavid Howells #if 0 418feae131SDavid Howells #define kenter(FMT, ...) \ 428feae131SDavid Howells printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) 438feae131SDavid Howells #define kleave(FMT, ...) \ 448feae131SDavid Howells printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) 458feae131SDavid Howells #define kdebug(FMT, ...) \ 468feae131SDavid Howells printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__) 478feae131SDavid Howells #else 488feae131SDavid Howells #define kenter(FMT, ...) \ 498feae131SDavid Howells no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) 508feae131SDavid Howells #define kleave(FMT, ...) \ 518feae131SDavid Howells no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) 528feae131SDavid Howells #define kdebug(FMT, ...) \ 538feae131SDavid Howells no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) 548feae131SDavid Howells #endif 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds void *high_memory; 571da177e4SLinus Torvalds struct page *mem_map; 581da177e4SLinus Torvalds unsigned long max_mapnr; 591da177e4SLinus Torvalds unsigned long num_physpages; 604266c97aSHugh Dickins unsigned long highest_memmap_pfn; 6100a62ce9SKOSAKI Motohiro struct percpu_counter vm_committed_as; 621da177e4SLinus Torvalds int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ 631da177e4SLinus Torvalds int sysctl_overcommit_ratio = 50; /* default is 50% */ 641da177e4SLinus Torvalds int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; 65fc4d5c29SDavid Howells int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; 661da177e4SLinus Torvalds int heap_stack_gap = 0; 671da177e4SLinus Torvalds 6833e5d769SDavid Howells atomic_long_t mmap_pages_allocated; 698feae131SDavid Howells 701da177e4SLinus Torvalds EXPORT_SYMBOL(mem_map); 716a04de6dSWu, Bryan EXPORT_SYMBOL(num_physpages); 721da177e4SLinus Torvalds 738feae131SDavid Howells /* list of mapped, potentially shareable regions */ 748feae131SDavid Howells static struct kmem_cache *vm_region_jar; 758feae131SDavid Howells struct rb_root nommu_region_tree = RB_ROOT; 768feae131SDavid Howells DECLARE_RWSEM(nommu_region_sem); 771da177e4SLinus Torvalds 78f0f37e2fSAlexey Dobriyan const struct vm_operations_struct generic_file_vm_ops = { 791da177e4SLinus Torvalds }; 801da177e4SLinus Torvalds 811da177e4SLinus Torvalds /* 821da177e4SLinus Torvalds * Return the total memory allocated for this pointer, not 831da177e4SLinus Torvalds * just what the caller asked for. 841da177e4SLinus Torvalds * 851da177e4SLinus Torvalds * Doesn't have to be accurate, i.e. may have races. 861da177e4SLinus Torvalds */ 871da177e4SLinus Torvalds unsigned int kobjsize(const void *objp) 881da177e4SLinus Torvalds { 891da177e4SLinus Torvalds struct page *page; 901da177e4SLinus Torvalds 914016a139SMichael Hennerich /* 924016a139SMichael Hennerich * If the object we have should not have ksize performed on it, 934016a139SMichael Hennerich * return size of 0 944016a139SMichael Hennerich */ 955a1603beSPaul Mundt if (!objp || !virt_addr_valid(objp)) 966cfd53fcSPaul Mundt return 0; 976cfd53fcSPaul Mundt 986cfd53fcSPaul Mundt page = virt_to_head_page(objp); 996cfd53fcSPaul Mundt 1006cfd53fcSPaul Mundt /* 1016cfd53fcSPaul Mundt * If the allocator sets PageSlab, we know the pointer came from 1026cfd53fcSPaul Mundt * kmalloc(). 1036cfd53fcSPaul Mundt */ 1041da177e4SLinus Torvalds if (PageSlab(page)) 1051da177e4SLinus Torvalds return ksize(objp); 1061da177e4SLinus Torvalds 1076cfd53fcSPaul Mundt /* 108ab2e83eaSPaul Mundt * If it's not a compound page, see if we have a matching VMA 109ab2e83eaSPaul Mundt * region. This test is intentionally done in reverse order, 110ab2e83eaSPaul Mundt * so if there's no VMA, we still fall through and hand back 111ab2e83eaSPaul Mundt * PAGE_SIZE for 0-order pages. 112ab2e83eaSPaul Mundt */ 113ab2e83eaSPaul Mundt if (!PageCompound(page)) { 114ab2e83eaSPaul Mundt struct vm_area_struct *vma; 115ab2e83eaSPaul Mundt 116ab2e83eaSPaul Mundt vma = find_vma(current->mm, (unsigned long)objp); 117ab2e83eaSPaul Mundt if (vma) 118ab2e83eaSPaul Mundt return vma->vm_end - vma->vm_start; 119ab2e83eaSPaul Mundt } 120ab2e83eaSPaul Mundt 121ab2e83eaSPaul Mundt /* 1226cfd53fcSPaul Mundt * The ksize() function is only guaranteed to work for pointers 1235a1603beSPaul Mundt * returned by kmalloc(). So handle arbitrary pointers here. 1246cfd53fcSPaul Mundt */ 1255a1603beSPaul Mundt return PAGE_SIZE << compound_order(page); 1261da177e4SLinus Torvalds } 1271da177e4SLinus Torvalds 128b291f000SNick Piggin int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 1294266c97aSHugh Dickins unsigned long start, int nr_pages, unsigned int foll_flags, 13053a7706dSMichel Lespinasse struct page **pages, struct vm_area_struct **vmas, 13153a7706dSMichel Lespinasse int *retry) 1321da177e4SLinus Torvalds { 133910e46daSSonic Zhang struct vm_area_struct *vma; 1347b4d5b8bSDavid Howells unsigned long vm_flags; 1357b4d5b8bSDavid Howells int i; 1367b4d5b8bSDavid Howells 1377b4d5b8bSDavid Howells /* calculate required read or write permissions. 13858fa879eSHugh Dickins * If FOLL_FORCE is set, we only require the "MAY" flags. 1397b4d5b8bSDavid Howells */ 14058fa879eSHugh Dickins vm_flags = (foll_flags & FOLL_WRITE) ? 14158fa879eSHugh Dickins (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); 14258fa879eSHugh Dickins vm_flags &= (foll_flags & FOLL_FORCE) ? 14358fa879eSHugh Dickins (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); 1441da177e4SLinus Torvalds 1459d73777eSPeter Zijlstra for (i = 0; i < nr_pages; i++) { 1467561e8caSDavid Howells vma = find_vma(mm, start); 147910e46daSSonic Zhang if (!vma) 1487b4d5b8bSDavid Howells goto finish_or_fault; 1497b4d5b8bSDavid Howells 1507b4d5b8bSDavid Howells /* protect what we can, including chardevs */ 1511c3aff1cSHugh Dickins if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) || 1521c3aff1cSHugh Dickins !(vm_flags & vma->vm_flags)) 1537b4d5b8bSDavid Howells goto finish_or_fault; 154910e46daSSonic Zhang 1551da177e4SLinus Torvalds if (pages) { 1561da177e4SLinus Torvalds pages[i] = virt_to_page(start); 1571da177e4SLinus Torvalds if (pages[i]) 1581da177e4SLinus Torvalds page_cache_get(pages[i]); 1591da177e4SLinus Torvalds } 1601da177e4SLinus Torvalds if (vmas) 161910e46daSSonic Zhang vmas[i] = vma; 162e1ee65d8SDavid Howells start = (start + PAGE_SIZE) & PAGE_MASK; 1631da177e4SLinus Torvalds } 1647b4d5b8bSDavid Howells 1657b4d5b8bSDavid Howells return i; 1667b4d5b8bSDavid Howells 1677b4d5b8bSDavid Howells finish_or_fault: 1687b4d5b8bSDavid Howells return i ? : -EFAULT; 1691da177e4SLinus Torvalds } 170b291f000SNick Piggin 171b291f000SNick Piggin /* 172b291f000SNick Piggin * get a list of pages in an address range belonging to the specified process 173b291f000SNick Piggin * and indicate the VMA that covers each page 174b291f000SNick Piggin * - this is potentially dodgy as we may end incrementing the page count of a 175b291f000SNick Piggin * slab page or a secondary page from a compound page 176b291f000SNick Piggin * - don't permit access to VMAs that don't support it, such as I/O mappings 177b291f000SNick Piggin */ 178b291f000SNick Piggin int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, 1799d73777eSPeter Zijlstra unsigned long start, int nr_pages, int write, int force, 180b291f000SNick Piggin struct page **pages, struct vm_area_struct **vmas) 181b291f000SNick Piggin { 182b291f000SNick Piggin int flags = 0; 183b291f000SNick Piggin 184b291f000SNick Piggin if (write) 18558fa879eSHugh Dickins flags |= FOLL_WRITE; 186b291f000SNick Piggin if (force) 18758fa879eSHugh Dickins flags |= FOLL_FORCE; 188b291f000SNick Piggin 18953a7706dSMichel Lespinasse return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas, 19053a7706dSMichel Lespinasse NULL); 191b291f000SNick Piggin } 19266aa2b4bSGreg Ungerer EXPORT_SYMBOL(get_user_pages); 19366aa2b4bSGreg Ungerer 194dfc2f91aSPaul Mundt /** 195dfc2f91aSPaul Mundt * follow_pfn - look up PFN at a user virtual address 196dfc2f91aSPaul Mundt * @vma: memory mapping 197dfc2f91aSPaul Mundt * @address: user virtual address 198dfc2f91aSPaul Mundt * @pfn: location to store found PFN 199dfc2f91aSPaul Mundt * 200dfc2f91aSPaul Mundt * Only IO mappings and raw PFN mappings are allowed. 201dfc2f91aSPaul Mundt * 202dfc2f91aSPaul Mundt * Returns zero and the pfn at @pfn on success, -ve otherwise. 203dfc2f91aSPaul Mundt */ 204dfc2f91aSPaul Mundt int follow_pfn(struct vm_area_struct *vma, unsigned long address, 205dfc2f91aSPaul Mundt unsigned long *pfn) 206dfc2f91aSPaul Mundt { 207dfc2f91aSPaul Mundt if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 208dfc2f91aSPaul Mundt return -EINVAL; 209dfc2f91aSPaul Mundt 210dfc2f91aSPaul Mundt *pfn = address >> PAGE_SHIFT; 211dfc2f91aSPaul Mundt return 0; 212dfc2f91aSPaul Mundt } 213dfc2f91aSPaul Mundt EXPORT_SYMBOL(follow_pfn); 214dfc2f91aSPaul Mundt 2151da177e4SLinus Torvalds DEFINE_RWLOCK(vmlist_lock); 2161da177e4SLinus Torvalds struct vm_struct *vmlist; 2171da177e4SLinus Torvalds 218b3bdda02SChristoph Lameter void vfree(const void *addr) 2191da177e4SLinus Torvalds { 2201da177e4SLinus Torvalds kfree(addr); 2211da177e4SLinus Torvalds } 222b5073173SPaul Mundt EXPORT_SYMBOL(vfree); 2231da177e4SLinus Torvalds 224dd0fc66fSAl Viro void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) 2251da177e4SLinus Torvalds { 2261da177e4SLinus Torvalds /* 2278518609dSRobert P. J. Day * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() 2288518609dSRobert P. J. Day * returns only a logical address. 2291da177e4SLinus Torvalds */ 23084097518SNick Piggin return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); 2311da177e4SLinus Torvalds } 232b5073173SPaul Mundt EXPORT_SYMBOL(__vmalloc); 2331da177e4SLinus Torvalds 234f905bc44SPaul Mundt void *vmalloc_user(unsigned long size) 235f905bc44SPaul Mundt { 236f905bc44SPaul Mundt void *ret; 237f905bc44SPaul Mundt 238f905bc44SPaul Mundt ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, 239f905bc44SPaul Mundt PAGE_KERNEL); 240f905bc44SPaul Mundt if (ret) { 241f905bc44SPaul Mundt struct vm_area_struct *vma; 242f905bc44SPaul Mundt 243f905bc44SPaul Mundt down_write(¤t->mm->mmap_sem); 244f905bc44SPaul Mundt vma = find_vma(current->mm, (unsigned long)ret); 245f905bc44SPaul Mundt if (vma) 246f905bc44SPaul Mundt vma->vm_flags |= VM_USERMAP; 247f905bc44SPaul Mundt up_write(¤t->mm->mmap_sem); 248f905bc44SPaul Mundt } 249f905bc44SPaul Mundt 250f905bc44SPaul Mundt return ret; 251f905bc44SPaul Mundt } 252f905bc44SPaul Mundt EXPORT_SYMBOL(vmalloc_user); 253f905bc44SPaul Mundt 254b3bdda02SChristoph Lameter struct page *vmalloc_to_page(const void *addr) 2551da177e4SLinus Torvalds { 2561da177e4SLinus Torvalds return virt_to_page(addr); 2571da177e4SLinus Torvalds } 258b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_page); 2591da177e4SLinus Torvalds 260b3bdda02SChristoph Lameter unsigned long vmalloc_to_pfn(const void *addr) 2611da177e4SLinus Torvalds { 2621da177e4SLinus Torvalds return page_to_pfn(virt_to_page(addr)); 2631da177e4SLinus Torvalds } 264b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_pfn); 2651da177e4SLinus Torvalds 2661da177e4SLinus Torvalds long vread(char *buf, char *addr, unsigned long count) 2671da177e4SLinus Torvalds { 2681da177e4SLinus Torvalds memcpy(buf, addr, count); 2691da177e4SLinus Torvalds return count; 2701da177e4SLinus Torvalds } 2711da177e4SLinus Torvalds 2721da177e4SLinus Torvalds long vwrite(char *buf, char *addr, unsigned long count) 2731da177e4SLinus Torvalds { 2741da177e4SLinus Torvalds /* Don't allow overflow */ 2751da177e4SLinus Torvalds if ((unsigned long) addr + count < count) 2761da177e4SLinus Torvalds count = -(unsigned long) addr; 2771da177e4SLinus Torvalds 2781da177e4SLinus Torvalds memcpy(addr, buf, count); 2791da177e4SLinus Torvalds return(count); 2801da177e4SLinus Torvalds } 2811da177e4SLinus Torvalds 2821da177e4SLinus Torvalds /* 2831da177e4SLinus Torvalds * vmalloc - allocate virtually continguos memory 2841da177e4SLinus Torvalds * 2851da177e4SLinus Torvalds * @size: allocation size 2861da177e4SLinus Torvalds * 2871da177e4SLinus Torvalds * Allocate enough pages to cover @size from the page level 2881da177e4SLinus Torvalds * allocator and map them into continguos kernel virtual space. 2891da177e4SLinus Torvalds * 290c1c8897fSMichael Opdenacker * For tight control over page level allocator and protection flags 2911da177e4SLinus Torvalds * use __vmalloc() instead. 2921da177e4SLinus Torvalds */ 2931da177e4SLinus Torvalds void *vmalloc(unsigned long size) 2941da177e4SLinus Torvalds { 2951da177e4SLinus Torvalds return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); 2961da177e4SLinus Torvalds } 297f6138882SAndrew Morton EXPORT_SYMBOL(vmalloc); 298f6138882SAndrew Morton 299e1ca7788SDave Young /* 300e1ca7788SDave Young * vzalloc - allocate virtually continguos memory with zero fill 301e1ca7788SDave Young * 302e1ca7788SDave Young * @size: allocation size 303e1ca7788SDave Young * 304e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 305e1ca7788SDave Young * allocator and map them into continguos kernel virtual space. 306e1ca7788SDave Young * The memory allocated is set to zero. 307e1ca7788SDave Young * 308e1ca7788SDave Young * For tight control over page level allocator and protection flags 309e1ca7788SDave Young * use __vmalloc() instead. 310e1ca7788SDave Young */ 311e1ca7788SDave Young void *vzalloc(unsigned long size) 312e1ca7788SDave Young { 313e1ca7788SDave Young return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, 314e1ca7788SDave Young PAGE_KERNEL); 315e1ca7788SDave Young } 316e1ca7788SDave Young EXPORT_SYMBOL(vzalloc); 317e1ca7788SDave Young 318e1ca7788SDave Young /** 319e1ca7788SDave Young * vmalloc_node - allocate memory on a specific node 320e1ca7788SDave Young * @size: allocation size 321e1ca7788SDave Young * @node: numa node 322e1ca7788SDave Young * 323e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 324e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 325e1ca7788SDave Young * 326e1ca7788SDave Young * For tight control over page level allocator and protection flags 327e1ca7788SDave Young * use __vmalloc() instead. 328e1ca7788SDave Young */ 329f6138882SAndrew Morton void *vmalloc_node(unsigned long size, int node) 330f6138882SAndrew Morton { 331f6138882SAndrew Morton return vmalloc(size); 332f6138882SAndrew Morton } 3339a14f653SPaul Mundt EXPORT_SYMBOL(vmalloc_node); 334e1ca7788SDave Young 335e1ca7788SDave Young /** 336e1ca7788SDave Young * vzalloc_node - allocate memory on a specific node with zero fill 337e1ca7788SDave Young * @size: allocation size 338e1ca7788SDave Young * @node: numa node 339e1ca7788SDave Young * 340e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 341e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 342e1ca7788SDave Young * The memory allocated is set to zero. 343e1ca7788SDave Young * 344e1ca7788SDave Young * For tight control over page level allocator and protection flags 345e1ca7788SDave Young * use __vmalloc() instead. 346e1ca7788SDave Young */ 347e1ca7788SDave Young void *vzalloc_node(unsigned long size, int node) 348e1ca7788SDave Young { 349e1ca7788SDave Young return vzalloc(size); 350e1ca7788SDave Young } 351e1ca7788SDave Young EXPORT_SYMBOL(vzalloc_node); 3521da177e4SLinus Torvalds 3531af446edSPaul Mundt #ifndef PAGE_KERNEL_EXEC 3541af446edSPaul Mundt # define PAGE_KERNEL_EXEC PAGE_KERNEL 3551af446edSPaul Mundt #endif 3561af446edSPaul Mundt 3571af446edSPaul Mundt /** 3581af446edSPaul Mundt * vmalloc_exec - allocate virtually contiguous, executable memory 3591af446edSPaul Mundt * @size: allocation size 3601af446edSPaul Mundt * 3611af446edSPaul Mundt * Kernel-internal function to allocate enough pages to cover @size 3621af446edSPaul Mundt * the page level allocator and map them into contiguous and 3631af446edSPaul Mundt * executable kernel virtual space. 3641af446edSPaul Mundt * 3651af446edSPaul Mundt * For tight control over page level allocator and protection flags 3661af446edSPaul Mundt * use __vmalloc() instead. 3671af446edSPaul Mundt */ 3681af446edSPaul Mundt 3691af446edSPaul Mundt void *vmalloc_exec(unsigned long size) 3701af446edSPaul Mundt { 3711af446edSPaul Mundt return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); 3721af446edSPaul Mundt } 3731af446edSPaul Mundt 374b5073173SPaul Mundt /** 375b5073173SPaul Mundt * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 3761da177e4SLinus Torvalds * @size: allocation size 3771da177e4SLinus Torvalds * 3781da177e4SLinus Torvalds * Allocate enough 32bit PA addressable pages to cover @size from the 3791da177e4SLinus Torvalds * page level allocator and map them into continguos kernel virtual space. 3801da177e4SLinus Torvalds */ 3811da177e4SLinus Torvalds void *vmalloc_32(unsigned long size) 3821da177e4SLinus Torvalds { 3831da177e4SLinus Torvalds return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); 3841da177e4SLinus Torvalds } 385b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32); 386b5073173SPaul Mundt 387b5073173SPaul Mundt /** 388b5073173SPaul Mundt * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 389b5073173SPaul Mundt * @size: allocation size 390b5073173SPaul Mundt * 391b5073173SPaul Mundt * The resulting memory area is 32bit addressable and zeroed so it can be 392b5073173SPaul Mundt * mapped to userspace without leaking data. 393f905bc44SPaul Mundt * 394f905bc44SPaul Mundt * VM_USERMAP is set on the corresponding VMA so that subsequent calls to 395f905bc44SPaul Mundt * remap_vmalloc_range() are permissible. 396b5073173SPaul Mundt */ 397b5073173SPaul Mundt void *vmalloc_32_user(unsigned long size) 398b5073173SPaul Mundt { 399f905bc44SPaul Mundt /* 400f905bc44SPaul Mundt * We'll have to sort out the ZONE_DMA bits for 64-bit, 401f905bc44SPaul Mundt * but for now this can simply use vmalloc_user() directly. 402f905bc44SPaul Mundt */ 403f905bc44SPaul Mundt return vmalloc_user(size); 404b5073173SPaul Mundt } 405b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32_user); 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) 4081da177e4SLinus Torvalds { 4091da177e4SLinus Torvalds BUG(); 4101da177e4SLinus Torvalds return NULL; 4111da177e4SLinus Torvalds } 412b5073173SPaul Mundt EXPORT_SYMBOL(vmap); 4131da177e4SLinus Torvalds 414b3bdda02SChristoph Lameter void vunmap(const void *addr) 4151da177e4SLinus Torvalds { 4161da177e4SLinus Torvalds BUG(); 4171da177e4SLinus Torvalds } 418b5073173SPaul Mundt EXPORT_SYMBOL(vunmap); 4191da177e4SLinus Torvalds 420eb6434d9SPaul Mundt void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) 421eb6434d9SPaul Mundt { 422eb6434d9SPaul Mundt BUG(); 423eb6434d9SPaul Mundt return NULL; 424eb6434d9SPaul Mundt } 425eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_map_ram); 426eb6434d9SPaul Mundt 427eb6434d9SPaul Mundt void vm_unmap_ram(const void *mem, unsigned int count) 428eb6434d9SPaul Mundt { 429eb6434d9SPaul Mundt BUG(); 430eb6434d9SPaul Mundt } 431eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_unmap_ram); 432eb6434d9SPaul Mundt 433eb6434d9SPaul Mundt void vm_unmap_aliases(void) 434eb6434d9SPaul Mundt { 435eb6434d9SPaul Mundt } 436eb6434d9SPaul Mundt EXPORT_SYMBOL_GPL(vm_unmap_aliases); 437eb6434d9SPaul Mundt 4381da177e4SLinus Torvalds /* 4391eeb66a1SChristoph Hellwig * Implement a stub for vmalloc_sync_all() if the architecture chose not to 4401eeb66a1SChristoph Hellwig * have one. 4411eeb66a1SChristoph Hellwig */ 4421eeb66a1SChristoph Hellwig void __attribute__((weak)) vmalloc_sync_all(void) 4431eeb66a1SChristoph Hellwig { 4441eeb66a1SChristoph Hellwig } 4451eeb66a1SChristoph Hellwig 44629c185e5SPaul Mundt /** 44729c185e5SPaul Mundt * alloc_vm_area - allocate a range of kernel address space 44829c185e5SPaul Mundt * @size: size of the area 44929c185e5SPaul Mundt * 45029c185e5SPaul Mundt * Returns: NULL on failure, vm_struct on success 45129c185e5SPaul Mundt * 45229c185e5SPaul Mundt * This function reserves a range of kernel address space, and 45329c185e5SPaul Mundt * allocates pagetables to map that range. No actual mappings 45429c185e5SPaul Mundt * are created. If the kernel address space is not shared 45529c185e5SPaul Mundt * between processes, it syncs the pagetable across all 45629c185e5SPaul Mundt * processes. 45729c185e5SPaul Mundt */ 45829c185e5SPaul Mundt struct vm_struct *alloc_vm_area(size_t size) 45929c185e5SPaul Mundt { 46029c185e5SPaul Mundt BUG(); 46129c185e5SPaul Mundt return NULL; 46229c185e5SPaul Mundt } 46329c185e5SPaul Mundt EXPORT_SYMBOL_GPL(alloc_vm_area); 46429c185e5SPaul Mundt 46529c185e5SPaul Mundt void free_vm_area(struct vm_struct *area) 46629c185e5SPaul Mundt { 46729c185e5SPaul Mundt BUG(); 46829c185e5SPaul Mundt } 46929c185e5SPaul Mundt EXPORT_SYMBOL_GPL(free_vm_area); 47029c185e5SPaul Mundt 471b5073173SPaul Mundt int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 472b5073173SPaul Mundt struct page *page) 473b5073173SPaul Mundt { 474b5073173SPaul Mundt return -EINVAL; 475b5073173SPaul Mundt } 476b5073173SPaul Mundt EXPORT_SYMBOL(vm_insert_page); 477b5073173SPaul Mundt 4781eeb66a1SChristoph Hellwig /* 4791da177e4SLinus Torvalds * sys_brk() for the most part doesn't need the global kernel 4801da177e4SLinus Torvalds * lock, except when an application is doing something nasty 4811da177e4SLinus Torvalds * like trying to un-brk an area that has already been mapped 4821da177e4SLinus Torvalds * to a regular file. in this case, the unmapping will need 4831da177e4SLinus Torvalds * to invoke file system routines that need the global lock. 4841da177e4SLinus Torvalds */ 4856a6160a7SHeiko Carstens SYSCALL_DEFINE1(brk, unsigned long, brk) 4861da177e4SLinus Torvalds { 4871da177e4SLinus Torvalds struct mm_struct *mm = current->mm; 4881da177e4SLinus Torvalds 4891da177e4SLinus Torvalds if (brk < mm->start_brk || brk > mm->context.end_brk) 4901da177e4SLinus Torvalds return mm->brk; 4911da177e4SLinus Torvalds 4921da177e4SLinus Torvalds if (mm->brk == brk) 4931da177e4SLinus Torvalds return mm->brk; 4941da177e4SLinus Torvalds 4951da177e4SLinus Torvalds /* 4961da177e4SLinus Torvalds * Always allow shrinking brk 4971da177e4SLinus Torvalds */ 4981da177e4SLinus Torvalds if (brk <= mm->brk) { 4991da177e4SLinus Torvalds mm->brk = brk; 5001da177e4SLinus Torvalds return brk; 5011da177e4SLinus Torvalds } 5021da177e4SLinus Torvalds 5031da177e4SLinus Torvalds /* 5041da177e4SLinus Torvalds * Ok, looks good - let it rip. 5051da177e4SLinus Torvalds */ 506cfe79c00SMike Frysinger flush_icache_range(mm->brk, brk); 5071da177e4SLinus Torvalds return mm->brk = brk; 5081da177e4SLinus Torvalds } 5091da177e4SLinus Torvalds 5108feae131SDavid Howells /* 5118feae131SDavid Howells * initialise the VMA and region record slabs 5128feae131SDavid Howells */ 5138feae131SDavid Howells void __init mmap_init(void) 5141da177e4SLinus Torvalds { 51500a62ce9SKOSAKI Motohiro int ret; 51600a62ce9SKOSAKI Motohiro 51700a62ce9SKOSAKI Motohiro ret = percpu_counter_init(&vm_committed_as, 0); 51800a62ce9SKOSAKI Motohiro VM_BUG_ON(ret); 51933e5d769SDavid Howells vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC); 5208feae131SDavid Howells } 5211da177e4SLinus Torvalds 5228feae131SDavid Howells /* 5238feae131SDavid Howells * validate the region tree 5248feae131SDavid Howells * - the caller must hold the region lock 5258feae131SDavid Howells */ 5268feae131SDavid Howells #ifdef CONFIG_DEBUG_NOMMU_REGIONS 5278feae131SDavid Howells static noinline void validate_nommu_regions(void) 5288feae131SDavid Howells { 5298feae131SDavid Howells struct vm_region *region, *last; 5308feae131SDavid Howells struct rb_node *p, *lastp; 5311da177e4SLinus Torvalds 5328feae131SDavid Howells lastp = rb_first(&nommu_region_tree); 5338feae131SDavid Howells if (!lastp) 5348feae131SDavid Howells return; 5358feae131SDavid Howells 5368feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 53733e5d769SDavid Howells BUG_ON(unlikely(last->vm_end <= last->vm_start)); 53833e5d769SDavid Howells BUG_ON(unlikely(last->vm_top < last->vm_end)); 5398feae131SDavid Howells 5408feae131SDavid Howells while ((p = rb_next(lastp))) { 5418feae131SDavid Howells region = rb_entry(p, struct vm_region, vm_rb); 5428feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 5438feae131SDavid Howells 54433e5d769SDavid Howells BUG_ON(unlikely(region->vm_end <= region->vm_start)); 54533e5d769SDavid Howells BUG_ON(unlikely(region->vm_top < region->vm_end)); 54633e5d769SDavid Howells BUG_ON(unlikely(region->vm_start < last->vm_top)); 5478feae131SDavid Howells 5488feae131SDavid Howells lastp = p; 5491da177e4SLinus Torvalds } 5501da177e4SLinus Torvalds } 5518feae131SDavid Howells #else 55233e5d769SDavid Howells static void validate_nommu_regions(void) 55333e5d769SDavid Howells { 55433e5d769SDavid Howells } 5558feae131SDavid Howells #endif 5568feae131SDavid Howells 5578feae131SDavid Howells /* 5588feae131SDavid Howells * add a region into the global tree 5598feae131SDavid Howells */ 5608feae131SDavid Howells static void add_nommu_region(struct vm_region *region) 5618feae131SDavid Howells { 5628feae131SDavid Howells struct vm_region *pregion; 5638feae131SDavid Howells struct rb_node **p, *parent; 5648feae131SDavid Howells 5658feae131SDavid Howells validate_nommu_regions(); 5668feae131SDavid Howells 5678feae131SDavid Howells parent = NULL; 5688feae131SDavid Howells p = &nommu_region_tree.rb_node; 5698feae131SDavid Howells while (*p) { 5708feae131SDavid Howells parent = *p; 5718feae131SDavid Howells pregion = rb_entry(parent, struct vm_region, vm_rb); 5728feae131SDavid Howells if (region->vm_start < pregion->vm_start) 5738feae131SDavid Howells p = &(*p)->rb_left; 5748feae131SDavid Howells else if (region->vm_start > pregion->vm_start) 5758feae131SDavid Howells p = &(*p)->rb_right; 5768feae131SDavid Howells else if (pregion == region) 5778feae131SDavid Howells return; 5788feae131SDavid Howells else 5798feae131SDavid Howells BUG(); 5808feae131SDavid Howells } 5818feae131SDavid Howells 5828feae131SDavid Howells rb_link_node(®ion->vm_rb, parent, p); 5838feae131SDavid Howells rb_insert_color(®ion->vm_rb, &nommu_region_tree); 5848feae131SDavid Howells 5858feae131SDavid Howells validate_nommu_regions(); 5868feae131SDavid Howells } 5878feae131SDavid Howells 5888feae131SDavid Howells /* 5898feae131SDavid Howells * delete a region from the global tree 5908feae131SDavid Howells */ 5918feae131SDavid Howells static void delete_nommu_region(struct vm_region *region) 5928feae131SDavid Howells { 5938feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5948feae131SDavid Howells 5958feae131SDavid Howells validate_nommu_regions(); 5968feae131SDavid Howells rb_erase(®ion->vm_rb, &nommu_region_tree); 5978feae131SDavid Howells validate_nommu_regions(); 5988feae131SDavid Howells } 5998feae131SDavid Howells 6008feae131SDavid Howells /* 6018feae131SDavid Howells * free a contiguous series of pages 6028feae131SDavid Howells */ 6038feae131SDavid Howells static void free_page_series(unsigned long from, unsigned long to) 6048feae131SDavid Howells { 6058feae131SDavid Howells for (; from < to; from += PAGE_SIZE) { 6068feae131SDavid Howells struct page *page = virt_to_page(from); 6078feae131SDavid Howells 6088feae131SDavid Howells kdebug("- free %lx", from); 60933e5d769SDavid Howells atomic_long_dec(&mmap_pages_allocated); 6108feae131SDavid Howells if (page_count(page) != 1) 61133e5d769SDavid Howells kdebug("free page %p: refcount not one: %d", 61233e5d769SDavid Howells page, page_count(page)); 6138feae131SDavid Howells put_page(page); 6148feae131SDavid Howells } 6158feae131SDavid Howells } 6168feae131SDavid Howells 6178feae131SDavid Howells /* 6188feae131SDavid Howells * release a reference to a region 61933e5d769SDavid Howells * - the caller must hold the region semaphore for writing, which this releases 620dd8632a1SPaul Mundt * - the region may not have been added to the tree yet, in which case vm_top 6218feae131SDavid Howells * will equal vm_start 6228feae131SDavid Howells */ 6238feae131SDavid Howells static void __put_nommu_region(struct vm_region *region) 6248feae131SDavid Howells __releases(nommu_region_sem) 6258feae131SDavid Howells { 6261e2ae599SDavid Howells kenter("%p{%d}", region, region->vm_usage); 6278feae131SDavid Howells 6288feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 6298feae131SDavid Howells 6301e2ae599SDavid Howells if (--region->vm_usage == 0) { 631dd8632a1SPaul Mundt if (region->vm_top > region->vm_start) 6328feae131SDavid Howells delete_nommu_region(region); 6338feae131SDavid Howells up_write(&nommu_region_sem); 6348feae131SDavid Howells 6358feae131SDavid Howells if (region->vm_file) 6368feae131SDavid Howells fput(region->vm_file); 6378feae131SDavid Howells 6388feae131SDavid Howells /* IO memory and memory shared directly out of the pagecache 6398feae131SDavid Howells * from ramfs/tmpfs mustn't be released here */ 6408feae131SDavid Howells if (region->vm_flags & VM_MAPPED_COPY) { 6418feae131SDavid Howells kdebug("free series"); 642dd8632a1SPaul Mundt free_page_series(region->vm_start, region->vm_top); 6438feae131SDavid Howells } 6448feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 6458feae131SDavid Howells } else { 6468feae131SDavid Howells up_write(&nommu_region_sem); 6478feae131SDavid Howells } 6488feae131SDavid Howells } 6498feae131SDavid Howells 6508feae131SDavid Howells /* 6518feae131SDavid Howells * release a reference to a region 6528feae131SDavid Howells */ 6538feae131SDavid Howells static void put_nommu_region(struct vm_region *region) 6548feae131SDavid Howells { 6558feae131SDavid Howells down_write(&nommu_region_sem); 6568feae131SDavid Howells __put_nommu_region(region); 6578feae131SDavid Howells } 6581da177e4SLinus Torvalds 6593034097aSDavid Howells /* 660eb8cdec4SBernd Schmidt * update protection on a vma 661eb8cdec4SBernd Schmidt */ 662eb8cdec4SBernd Schmidt static void protect_vma(struct vm_area_struct *vma, unsigned long flags) 663eb8cdec4SBernd Schmidt { 664eb8cdec4SBernd Schmidt #ifdef CONFIG_MPU 665eb8cdec4SBernd Schmidt struct mm_struct *mm = vma->vm_mm; 666eb8cdec4SBernd Schmidt long start = vma->vm_start & PAGE_MASK; 667eb8cdec4SBernd Schmidt while (start < vma->vm_end) { 668eb8cdec4SBernd Schmidt protect_page(mm, start, flags); 669eb8cdec4SBernd Schmidt start += PAGE_SIZE; 670eb8cdec4SBernd Schmidt } 671eb8cdec4SBernd Schmidt update_protections(mm); 672eb8cdec4SBernd Schmidt #endif 673eb8cdec4SBernd Schmidt } 674eb8cdec4SBernd Schmidt 675eb8cdec4SBernd Schmidt /* 6763034097aSDavid Howells * add a VMA into a process's mm_struct in the appropriate place in the list 6778feae131SDavid Howells * and tree and add to the address space's page tree also if not an anonymous 6788feae131SDavid Howells * page 6793034097aSDavid Howells * - should be called with mm->mmap_sem held writelocked 6803034097aSDavid Howells */ 6818feae131SDavid Howells static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) 6823034097aSDavid Howells { 6836038def0SNamhyung Kim struct vm_area_struct *pvma, *prev; 6848feae131SDavid Howells struct address_space *mapping; 6856038def0SNamhyung Kim struct rb_node **p, *parent, *rb_prev; 6863034097aSDavid Howells 6878feae131SDavid Howells kenter(",%p", vma); 6888feae131SDavid Howells 6898feae131SDavid Howells BUG_ON(!vma->vm_region); 6908feae131SDavid Howells 6918feae131SDavid Howells mm->map_count++; 6928feae131SDavid Howells vma->vm_mm = mm; 6938feae131SDavid Howells 694eb8cdec4SBernd Schmidt protect_vma(vma, vma->vm_flags); 695eb8cdec4SBernd Schmidt 6968feae131SDavid Howells /* add the VMA to the mapping */ 6978feae131SDavid Howells if (vma->vm_file) { 6988feae131SDavid Howells mapping = vma->vm_file->f_mapping; 6998feae131SDavid Howells 7008feae131SDavid Howells flush_dcache_mmap_lock(mapping); 7018feae131SDavid Howells vma_prio_tree_insert(vma, &mapping->i_mmap); 7028feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 7038feae131SDavid Howells } 7048feae131SDavid Howells 7058feae131SDavid Howells /* add the VMA to the tree */ 7066038def0SNamhyung Kim parent = rb_prev = NULL; 7078feae131SDavid Howells p = &mm->mm_rb.rb_node; 7088feae131SDavid Howells while (*p) { 7098feae131SDavid Howells parent = *p; 7108feae131SDavid Howells pvma = rb_entry(parent, struct vm_area_struct, vm_rb); 7118feae131SDavid Howells 7128feae131SDavid Howells /* sort by: start addr, end addr, VMA struct addr in that order 7138feae131SDavid Howells * (the latter is necessary as we may get identical VMAs) */ 7148feae131SDavid Howells if (vma->vm_start < pvma->vm_start) 7158feae131SDavid Howells p = &(*p)->rb_left; 7166038def0SNamhyung Kim else if (vma->vm_start > pvma->vm_start) { 7176038def0SNamhyung Kim rb_prev = parent; 7188feae131SDavid Howells p = &(*p)->rb_right; 7196038def0SNamhyung Kim } else if (vma->vm_end < pvma->vm_end) 7208feae131SDavid Howells p = &(*p)->rb_left; 7216038def0SNamhyung Kim else if (vma->vm_end > pvma->vm_end) { 7226038def0SNamhyung Kim rb_prev = parent; 7238feae131SDavid Howells p = &(*p)->rb_right; 7246038def0SNamhyung Kim } else if (vma < pvma) 7258feae131SDavid Howells p = &(*p)->rb_left; 7266038def0SNamhyung Kim else if (vma > pvma) { 7276038def0SNamhyung Kim rb_prev = parent; 7288feae131SDavid Howells p = &(*p)->rb_right; 7296038def0SNamhyung Kim } else 7308feae131SDavid Howells BUG(); 7318feae131SDavid Howells } 7328feae131SDavid Howells 7338feae131SDavid Howells rb_link_node(&vma->vm_rb, parent, p); 7348feae131SDavid Howells rb_insert_color(&vma->vm_rb, &mm->mm_rb); 7358feae131SDavid Howells 7368feae131SDavid Howells /* add VMA to the VMA list also */ 7376038def0SNamhyung Kim prev = NULL; 7386038def0SNamhyung Kim if (rb_prev) 7396038def0SNamhyung Kim prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); 7403034097aSDavid Howells 7416038def0SNamhyung Kim __vma_link_list(mm, vma, prev, parent); 7428feae131SDavid Howells } 7438feae131SDavid Howells 7448feae131SDavid Howells /* 7458feae131SDavid Howells * delete a VMA from its owning mm_struct and address space 7468feae131SDavid Howells */ 7478feae131SDavid Howells static void delete_vma_from_mm(struct vm_area_struct *vma) 7488feae131SDavid Howells { 7498feae131SDavid Howells struct address_space *mapping; 7508feae131SDavid Howells struct mm_struct *mm = vma->vm_mm; 7518feae131SDavid Howells 7528feae131SDavid Howells kenter("%p", vma); 7538feae131SDavid Howells 754eb8cdec4SBernd Schmidt protect_vma(vma, 0); 755eb8cdec4SBernd Schmidt 7568feae131SDavid Howells mm->map_count--; 7578feae131SDavid Howells if (mm->mmap_cache == vma) 7588feae131SDavid Howells mm->mmap_cache = NULL; 7598feae131SDavid Howells 7608feae131SDavid Howells /* remove the VMA from the mapping */ 7618feae131SDavid Howells if (vma->vm_file) { 7628feae131SDavid Howells mapping = vma->vm_file->f_mapping; 7638feae131SDavid Howells 7648feae131SDavid Howells flush_dcache_mmap_lock(mapping); 7658feae131SDavid Howells vma_prio_tree_remove(vma, &mapping->i_mmap); 7668feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 7678feae131SDavid Howells } 7688feae131SDavid Howells 7698feae131SDavid Howells /* remove from the MM's tree and list */ 7708feae131SDavid Howells rb_erase(&vma->vm_rb, &mm->mm_rb); 771b951bf2cSNamhyung Kim 772b951bf2cSNamhyung Kim if (vma->vm_prev) 773b951bf2cSNamhyung Kim vma->vm_prev->vm_next = vma->vm_next; 774b951bf2cSNamhyung Kim else 775b951bf2cSNamhyung Kim mm->mmap = vma->vm_next; 776b951bf2cSNamhyung Kim 777b951bf2cSNamhyung Kim if (vma->vm_next) 778b951bf2cSNamhyung Kim vma->vm_next->vm_prev = vma->vm_prev; 7798feae131SDavid Howells 7808feae131SDavid Howells vma->vm_mm = NULL; 7818feae131SDavid Howells } 7828feae131SDavid Howells 7838feae131SDavid Howells /* 7848feae131SDavid Howells * destroy a VMA record 7858feae131SDavid Howells */ 7868feae131SDavid Howells static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) 7878feae131SDavid Howells { 7888feae131SDavid Howells kenter("%p", vma); 7898feae131SDavid Howells if (vma->vm_ops && vma->vm_ops->close) 7908feae131SDavid Howells vma->vm_ops->close(vma); 7918feae131SDavid Howells if (vma->vm_file) { 7928feae131SDavid Howells fput(vma->vm_file); 7938feae131SDavid Howells if (vma->vm_flags & VM_EXECUTABLE) 7948feae131SDavid Howells removed_exe_file_vma(mm); 7958feae131SDavid Howells } 7968feae131SDavid Howells put_nommu_region(vma->vm_region); 7978feae131SDavid Howells kmem_cache_free(vm_area_cachep, vma); 7983034097aSDavid Howells } 7993034097aSDavid Howells 8003034097aSDavid Howells /* 8013034097aSDavid Howells * look up the first VMA in which addr resides, NULL if none 8023034097aSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 8033034097aSDavid Howells */ 8043034097aSDavid Howells struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) 8053034097aSDavid Howells { 8068feae131SDavid Howells struct vm_area_struct *vma; 8073034097aSDavid Howells 8088feae131SDavid Howells /* check the cache first */ 8098feae131SDavid Howells vma = mm->mmap_cache; 8108feae131SDavid Howells if (vma && vma->vm_start <= addr && vma->vm_end > addr) 8118feae131SDavid Howells return vma; 8128feae131SDavid Howells 813e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 8148feae131SDavid Howells * resides) */ 815e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 8168feae131SDavid Howells if (vma->vm_start > addr) 8178feae131SDavid Howells return NULL; 8188feae131SDavid Howells if (vma->vm_end > addr) { 8198feae131SDavid Howells mm->mmap_cache = vma; 8208feae131SDavid Howells return vma; 8213034097aSDavid Howells } 8228feae131SDavid Howells } 8233034097aSDavid Howells 8243034097aSDavid Howells return NULL; 8253034097aSDavid Howells } 8263034097aSDavid Howells EXPORT_SYMBOL(find_vma); 8273034097aSDavid Howells 8283034097aSDavid Howells /* 829930e652aSDavid Howells * find a VMA 830930e652aSDavid Howells * - we don't extend stack VMAs under NOMMU conditions 831930e652aSDavid Howells */ 832930e652aSDavid Howells struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) 833930e652aSDavid Howells { 8347561e8caSDavid Howells return find_vma(mm, addr); 835930e652aSDavid Howells } 836930e652aSDavid Howells 8378feae131SDavid Howells /* 8388feae131SDavid Howells * expand a stack to a given address 8398feae131SDavid Howells * - not supported under NOMMU conditions 8408feae131SDavid Howells */ 84157c8f63eSGreg Ungerer int expand_stack(struct vm_area_struct *vma, unsigned long address) 84257c8f63eSGreg Ungerer { 84357c8f63eSGreg Ungerer return -ENOMEM; 84457c8f63eSGreg Ungerer } 84557c8f63eSGreg Ungerer 846930e652aSDavid Howells /* 8476fa5f80bSDavid Howells * look up the first VMA exactly that exactly matches addr 8486fa5f80bSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 8496fa5f80bSDavid Howells */ 8508feae131SDavid Howells static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, 8518feae131SDavid Howells unsigned long addr, 8528feae131SDavid Howells unsigned long len) 8531da177e4SLinus Torvalds { 8541da177e4SLinus Torvalds struct vm_area_struct *vma; 8558feae131SDavid Howells unsigned long end = addr + len; 8561da177e4SLinus Torvalds 8578feae131SDavid Howells /* check the cache first */ 8588feae131SDavid Howells vma = mm->mmap_cache; 8598feae131SDavid Howells if (vma && vma->vm_start == addr && vma->vm_end == end) 8601da177e4SLinus Torvalds return vma; 8618feae131SDavid Howells 862e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 8638feae131SDavid Howells * resides) */ 864e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 8658feae131SDavid Howells if (vma->vm_start < addr) 8668feae131SDavid Howells continue; 8678feae131SDavid Howells if (vma->vm_start > addr) 8688feae131SDavid Howells return NULL; 8698feae131SDavid Howells if (vma->vm_end == end) { 8708feae131SDavid Howells mm->mmap_cache = vma; 8718feae131SDavid Howells return vma; 8728feae131SDavid Howells } 8731da177e4SLinus Torvalds } 8741da177e4SLinus Torvalds 8751da177e4SLinus Torvalds return NULL; 8761da177e4SLinus Torvalds } 8771da177e4SLinus Torvalds 8783034097aSDavid Howells /* 8791da177e4SLinus Torvalds * determine whether a mapping should be permitted and, if so, what sort of 8801da177e4SLinus Torvalds * mapping we're capable of supporting 8811da177e4SLinus Torvalds */ 8821da177e4SLinus Torvalds static int validate_mmap_request(struct file *file, 8831da177e4SLinus Torvalds unsigned long addr, 8841da177e4SLinus Torvalds unsigned long len, 8851da177e4SLinus Torvalds unsigned long prot, 8861da177e4SLinus Torvalds unsigned long flags, 8871da177e4SLinus Torvalds unsigned long pgoff, 8881da177e4SLinus Torvalds unsigned long *_capabilities) 8891da177e4SLinus Torvalds { 8908feae131SDavid Howells unsigned long capabilities, rlen; 8911da177e4SLinus Torvalds unsigned long reqprot = prot; 8921da177e4SLinus Torvalds int ret; 8931da177e4SLinus Torvalds 8941da177e4SLinus Torvalds /* do the simple checks first */ 89506aab5a3SDavid Howells if (flags & MAP_FIXED) { 8961da177e4SLinus Torvalds printk(KERN_DEBUG 8971da177e4SLinus Torvalds "%d: Can't do fixed-address/overlay mmap of RAM\n", 8981da177e4SLinus Torvalds current->pid); 8991da177e4SLinus Torvalds return -EINVAL; 9001da177e4SLinus Torvalds } 9011da177e4SLinus Torvalds 9021da177e4SLinus Torvalds if ((flags & MAP_TYPE) != MAP_PRIVATE && 9031da177e4SLinus Torvalds (flags & MAP_TYPE) != MAP_SHARED) 9041da177e4SLinus Torvalds return -EINVAL; 9051da177e4SLinus Torvalds 906f81cff0dSMike Frysinger if (!len) 9071da177e4SLinus Torvalds return -EINVAL; 9081da177e4SLinus Torvalds 909f81cff0dSMike Frysinger /* Careful about overflows.. */ 9108feae131SDavid Howells rlen = PAGE_ALIGN(len); 9118feae131SDavid Howells if (!rlen || rlen > TASK_SIZE) 912f81cff0dSMike Frysinger return -ENOMEM; 913f81cff0dSMike Frysinger 9141da177e4SLinus Torvalds /* offset overflow? */ 9158feae131SDavid Howells if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) 916f81cff0dSMike Frysinger return -EOVERFLOW; 9171da177e4SLinus Torvalds 9181da177e4SLinus Torvalds if (file) { 9191da177e4SLinus Torvalds /* validate file mapping requests */ 9201da177e4SLinus Torvalds struct address_space *mapping; 9211da177e4SLinus Torvalds 9221da177e4SLinus Torvalds /* files must support mmap */ 9231da177e4SLinus Torvalds if (!file->f_op || !file->f_op->mmap) 9241da177e4SLinus Torvalds return -ENODEV; 9251da177e4SLinus Torvalds 9261da177e4SLinus Torvalds /* work out if what we've got could possibly be shared 9271da177e4SLinus Torvalds * - we support chardevs that provide their own "memory" 9281da177e4SLinus Torvalds * - we support files/blockdevs that are memory backed 9291da177e4SLinus Torvalds */ 9301da177e4SLinus Torvalds mapping = file->f_mapping; 9311da177e4SLinus Torvalds if (!mapping) 932e9536ae7SJosef Sipek mapping = file->f_path.dentry->d_inode->i_mapping; 9331da177e4SLinus Torvalds 9341da177e4SLinus Torvalds capabilities = 0; 9351da177e4SLinus Torvalds if (mapping && mapping->backing_dev_info) 9361da177e4SLinus Torvalds capabilities = mapping->backing_dev_info->capabilities; 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds if (!capabilities) { 9391da177e4SLinus Torvalds /* no explicit capabilities set, so assume some 9401da177e4SLinus Torvalds * defaults */ 941e9536ae7SJosef Sipek switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { 9421da177e4SLinus Torvalds case S_IFREG: 9431da177e4SLinus Torvalds case S_IFBLK: 9441da177e4SLinus Torvalds capabilities = BDI_CAP_MAP_COPY; 9451da177e4SLinus Torvalds break; 9461da177e4SLinus Torvalds 9471da177e4SLinus Torvalds case S_IFCHR: 9481da177e4SLinus Torvalds capabilities = 9491da177e4SLinus Torvalds BDI_CAP_MAP_DIRECT | 9501da177e4SLinus Torvalds BDI_CAP_READ_MAP | 9511da177e4SLinus Torvalds BDI_CAP_WRITE_MAP; 9521da177e4SLinus Torvalds break; 9531da177e4SLinus Torvalds 9541da177e4SLinus Torvalds default: 9551da177e4SLinus Torvalds return -EINVAL; 9561da177e4SLinus Torvalds } 9571da177e4SLinus Torvalds } 9581da177e4SLinus Torvalds 9591da177e4SLinus Torvalds /* eliminate any capabilities that we can't support on this 9601da177e4SLinus Torvalds * device */ 9611da177e4SLinus Torvalds if (!file->f_op->get_unmapped_area) 9621da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 9631da177e4SLinus Torvalds if (!file->f_op->read) 9641da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_COPY; 9651da177e4SLinus Torvalds 96628d7a6aeSGraff Yang /* The file shall have been opened with read permission. */ 96728d7a6aeSGraff Yang if (!(file->f_mode & FMODE_READ)) 96828d7a6aeSGraff Yang return -EACCES; 96928d7a6aeSGraff Yang 9701da177e4SLinus Torvalds if (flags & MAP_SHARED) { 9711da177e4SLinus Torvalds /* do checks for writing, appending and locking */ 9721da177e4SLinus Torvalds if ((prot & PROT_WRITE) && 9731da177e4SLinus Torvalds !(file->f_mode & FMODE_WRITE)) 9741da177e4SLinus Torvalds return -EACCES; 9751da177e4SLinus Torvalds 976e9536ae7SJosef Sipek if (IS_APPEND(file->f_path.dentry->d_inode) && 9771da177e4SLinus Torvalds (file->f_mode & FMODE_WRITE)) 9781da177e4SLinus Torvalds return -EACCES; 9791da177e4SLinus Torvalds 980e9536ae7SJosef Sipek if (locks_verify_locked(file->f_path.dentry->d_inode)) 9811da177e4SLinus Torvalds return -EAGAIN; 9821da177e4SLinus Torvalds 9831da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_DIRECT)) 9841da177e4SLinus Torvalds return -ENODEV; 9851da177e4SLinus Torvalds 9861da177e4SLinus Torvalds /* we mustn't privatise shared mappings */ 9871da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_COPY; 9881da177e4SLinus Torvalds } 9891da177e4SLinus Torvalds else { 9901da177e4SLinus Torvalds /* we're going to read the file into private memory we 9911da177e4SLinus Torvalds * allocate */ 9921da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_COPY)) 9931da177e4SLinus Torvalds return -ENODEV; 9941da177e4SLinus Torvalds 9951da177e4SLinus Torvalds /* we don't permit a private writable mapping to be 9961da177e4SLinus Torvalds * shared with the backing device */ 9971da177e4SLinus Torvalds if (prot & PROT_WRITE) 9981da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 9991da177e4SLinus Torvalds } 10001da177e4SLinus Torvalds 10013c7b2045SBernd Schmidt if (capabilities & BDI_CAP_MAP_DIRECT) { 10023c7b2045SBernd Schmidt if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || 10033c7b2045SBernd Schmidt ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || 10043c7b2045SBernd Schmidt ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) 10053c7b2045SBernd Schmidt ) { 10063c7b2045SBernd Schmidt capabilities &= ~BDI_CAP_MAP_DIRECT; 10073c7b2045SBernd Schmidt if (flags & MAP_SHARED) { 10083c7b2045SBernd Schmidt printk(KERN_WARNING 10093c7b2045SBernd Schmidt "MAP_SHARED not completely supported on !MMU\n"); 10103c7b2045SBernd Schmidt return -EINVAL; 10113c7b2045SBernd Schmidt } 10123c7b2045SBernd Schmidt } 10133c7b2045SBernd Schmidt } 10143c7b2045SBernd Schmidt 10151da177e4SLinus Torvalds /* handle executable mappings and implied executable 10161da177e4SLinus Torvalds * mappings */ 1017e9536ae7SJosef Sipek if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { 10181da177e4SLinus Torvalds if (prot & PROT_EXEC) 10191da177e4SLinus Torvalds return -EPERM; 10201da177e4SLinus Torvalds } 10211da177e4SLinus Torvalds else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { 10221da177e4SLinus Torvalds /* handle implication of PROT_EXEC by PROT_READ */ 10231da177e4SLinus Torvalds if (current->personality & READ_IMPLIES_EXEC) { 10241da177e4SLinus Torvalds if (capabilities & BDI_CAP_EXEC_MAP) 10251da177e4SLinus Torvalds prot |= PROT_EXEC; 10261da177e4SLinus Torvalds } 10271da177e4SLinus Torvalds } 10281da177e4SLinus Torvalds else if ((prot & PROT_READ) && 10291da177e4SLinus Torvalds (prot & PROT_EXEC) && 10301da177e4SLinus Torvalds !(capabilities & BDI_CAP_EXEC_MAP) 10311da177e4SLinus Torvalds ) { 10321da177e4SLinus Torvalds /* backing file is not executable, try to copy */ 10331da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 10341da177e4SLinus Torvalds } 10351da177e4SLinus Torvalds } 10361da177e4SLinus Torvalds else { 10371da177e4SLinus Torvalds /* anonymous mappings are always memory backed and can be 10381da177e4SLinus Torvalds * privately mapped 10391da177e4SLinus Torvalds */ 10401da177e4SLinus Torvalds capabilities = BDI_CAP_MAP_COPY; 10411da177e4SLinus Torvalds 10421da177e4SLinus Torvalds /* handle PROT_EXEC implication by PROT_READ */ 10431da177e4SLinus Torvalds if ((prot & PROT_READ) && 10441da177e4SLinus Torvalds (current->personality & READ_IMPLIES_EXEC)) 10451da177e4SLinus Torvalds prot |= PROT_EXEC; 10461da177e4SLinus Torvalds } 10471da177e4SLinus Torvalds 10481da177e4SLinus Torvalds /* allow the security API to have its say */ 1049ed032189SEric Paris ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); 10501da177e4SLinus Torvalds if (ret < 0) 10511da177e4SLinus Torvalds return ret; 10521da177e4SLinus Torvalds 10531da177e4SLinus Torvalds /* looks okay */ 10541da177e4SLinus Torvalds *_capabilities = capabilities; 10551da177e4SLinus Torvalds return 0; 10561da177e4SLinus Torvalds } 10571da177e4SLinus Torvalds 10581da177e4SLinus Torvalds /* 10591da177e4SLinus Torvalds * we've determined that we can make the mapping, now translate what we 10601da177e4SLinus Torvalds * now know into VMA flags 10611da177e4SLinus Torvalds */ 10621da177e4SLinus Torvalds static unsigned long determine_vm_flags(struct file *file, 10631da177e4SLinus Torvalds unsigned long prot, 10641da177e4SLinus Torvalds unsigned long flags, 10651da177e4SLinus Torvalds unsigned long capabilities) 10661da177e4SLinus Torvalds { 10671da177e4SLinus Torvalds unsigned long vm_flags; 10681da177e4SLinus Torvalds 10691da177e4SLinus Torvalds vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); 10701da177e4SLinus Torvalds /* vm_flags |= mm->def_flags; */ 10711da177e4SLinus Torvalds 10721da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_DIRECT)) { 10731da177e4SLinus Torvalds /* attempt to share read-only copies of mapped file chunks */ 10743c7b2045SBernd Schmidt vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; 10751da177e4SLinus Torvalds if (file && !(prot & PROT_WRITE)) 10761da177e4SLinus Torvalds vm_flags |= VM_MAYSHARE; 10773c7b2045SBernd Schmidt } else { 10781da177e4SLinus Torvalds /* overlay a shareable mapping on the backing device or inode 10791da177e4SLinus Torvalds * if possible - used for chardevs, ramfs/tmpfs/shmfs and 10801da177e4SLinus Torvalds * romfs/cramfs */ 10813c7b2045SBernd Schmidt vm_flags |= VM_MAYSHARE | (capabilities & BDI_CAP_VMFLAGS); 10821da177e4SLinus Torvalds if (flags & MAP_SHARED) 10833c7b2045SBernd Schmidt vm_flags |= VM_SHARED; 10841da177e4SLinus Torvalds } 10851da177e4SLinus Torvalds 10861da177e4SLinus Torvalds /* refuse to let anyone share private mappings with this process if 10871da177e4SLinus Torvalds * it's being traced - otherwise breakpoints set in it may interfere 10881da177e4SLinus Torvalds * with another untraced process 10891da177e4SLinus Torvalds */ 1090fa8e26ccSRoland McGrath if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current)) 10911da177e4SLinus Torvalds vm_flags &= ~VM_MAYSHARE; 10921da177e4SLinus Torvalds 10931da177e4SLinus Torvalds return vm_flags; 10941da177e4SLinus Torvalds } 10951da177e4SLinus Torvalds 10961da177e4SLinus Torvalds /* 10978feae131SDavid Howells * set up a shared mapping on a file (the driver or filesystem provides and 10988feae131SDavid Howells * pins the storage) 10991da177e4SLinus Torvalds */ 11008feae131SDavid Howells static int do_mmap_shared_file(struct vm_area_struct *vma) 11011da177e4SLinus Torvalds { 11021da177e4SLinus Torvalds int ret; 11031da177e4SLinus Torvalds 11041da177e4SLinus Torvalds ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); 1105dd8632a1SPaul Mundt if (ret == 0) { 1106dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 1107645d83c5SDavid Howells return 0; 1108dd8632a1SPaul Mundt } 11091da177e4SLinus Torvalds if (ret != -ENOSYS) 11101da177e4SLinus Torvalds return ret; 11111da177e4SLinus Torvalds 11123fa30460SDavid Howells /* getting -ENOSYS indicates that direct mmap isn't possible (as 11133fa30460SDavid Howells * opposed to tried but failed) so we can only give a suitable error as 11143fa30460SDavid Howells * it's not possible to make a private copy if MAP_SHARED was given */ 11151da177e4SLinus Torvalds return -ENODEV; 11161da177e4SLinus Torvalds } 11171da177e4SLinus Torvalds 11181da177e4SLinus Torvalds /* 11191da177e4SLinus Torvalds * set up a private mapping or an anonymous shared mapping 11201da177e4SLinus Torvalds */ 11218feae131SDavid Howells static int do_mmap_private(struct vm_area_struct *vma, 11228feae131SDavid Howells struct vm_region *region, 1123645d83c5SDavid Howells unsigned long len, 1124645d83c5SDavid Howells unsigned long capabilities) 11251da177e4SLinus Torvalds { 11268feae131SDavid Howells struct page *pages; 11278feae131SDavid Howells unsigned long total, point, n, rlen; 11281da177e4SLinus Torvalds void *base; 11298feae131SDavid Howells int ret, order; 11301da177e4SLinus Torvalds 11311da177e4SLinus Torvalds /* invoke the file's mapping function so that it can keep track of 11321da177e4SLinus Torvalds * shared mappings on devices or memory 11331da177e4SLinus Torvalds * - VM_MAYSHARE will be set if it may attempt to share 11341da177e4SLinus Torvalds */ 1135645d83c5SDavid Howells if (capabilities & BDI_CAP_MAP_DIRECT) { 11361da177e4SLinus Torvalds ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); 1137dd8632a1SPaul Mundt if (ret == 0) { 11381da177e4SLinus Torvalds /* shouldn't return success if we're not sharing */ 1139dd8632a1SPaul Mundt BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); 1140dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 1141645d83c5SDavid Howells return 0; 11421da177e4SLinus Torvalds } 1143dd8632a1SPaul Mundt if (ret != -ENOSYS) 1144dd8632a1SPaul Mundt return ret; 11451da177e4SLinus Torvalds 11461da177e4SLinus Torvalds /* getting an ENOSYS error indicates that direct mmap isn't 11471da177e4SLinus Torvalds * possible (as opposed to tried but failed) so we'll try to 11481da177e4SLinus Torvalds * make a private copy of the data and map that instead */ 11491da177e4SLinus Torvalds } 11501da177e4SLinus Torvalds 11518feae131SDavid Howells rlen = PAGE_ALIGN(len); 11528feae131SDavid Howells 11531da177e4SLinus Torvalds /* allocate some memory to hold the mapping 11541da177e4SLinus Torvalds * - note that this may not return a page-aligned address if the object 11551da177e4SLinus Torvalds * we're allocating is smaller than a page 11561da177e4SLinus Torvalds */ 11578feae131SDavid Howells order = get_order(rlen); 11588feae131SDavid Howells kdebug("alloc order %d for %lx", order, len); 11598feae131SDavid Howells 11608feae131SDavid Howells pages = alloc_pages(GFP_KERNEL, order); 11618feae131SDavid Howells if (!pages) 11621da177e4SLinus Torvalds goto enomem; 11631da177e4SLinus Torvalds 11648feae131SDavid Howells total = 1 << order; 116533e5d769SDavid Howells atomic_long_add(total, &mmap_pages_allocated); 11661da177e4SLinus Torvalds 11678feae131SDavid Howells point = rlen >> PAGE_SHIFT; 1168dd8632a1SPaul Mundt 1169dd8632a1SPaul Mundt /* we allocated a power-of-2 sized page set, so we may want to trim off 1170dd8632a1SPaul Mundt * the excess */ 1171dd8632a1SPaul Mundt if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { 11728feae131SDavid Howells while (total > point) { 11738feae131SDavid Howells order = ilog2(total - point); 11748feae131SDavid Howells n = 1 << order; 11758feae131SDavid Howells kdebug("shave %lu/%lu @%lu", n, total - point, total); 117633e5d769SDavid Howells atomic_long_sub(n, &mmap_pages_allocated); 11778feae131SDavid Howells total -= n; 11788feae131SDavid Howells set_page_refcounted(pages + total); 11798feae131SDavid Howells __free_pages(pages + total, order); 11808feae131SDavid Howells } 1181dd8632a1SPaul Mundt } 11828feae131SDavid Howells 11838feae131SDavid Howells for (point = 1; point < total; point++) 11848feae131SDavid Howells set_page_refcounted(&pages[point]); 11858feae131SDavid Howells 11868feae131SDavid Howells base = page_address(pages); 11878feae131SDavid Howells region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; 11888feae131SDavid Howells region->vm_start = (unsigned long) base; 11898feae131SDavid Howells region->vm_end = region->vm_start + rlen; 1190dd8632a1SPaul Mundt region->vm_top = region->vm_start + (total << PAGE_SHIFT); 11918feae131SDavid Howells 11928feae131SDavid Howells vma->vm_start = region->vm_start; 11938feae131SDavid Howells vma->vm_end = region->vm_start + len; 11941da177e4SLinus Torvalds 11951da177e4SLinus Torvalds if (vma->vm_file) { 11961da177e4SLinus Torvalds /* read the contents of a file into the copy */ 11971da177e4SLinus Torvalds mm_segment_t old_fs; 11981da177e4SLinus Torvalds loff_t fpos; 11991da177e4SLinus Torvalds 12001da177e4SLinus Torvalds fpos = vma->vm_pgoff; 12011da177e4SLinus Torvalds fpos <<= PAGE_SHIFT; 12021da177e4SLinus Torvalds 12031da177e4SLinus Torvalds old_fs = get_fs(); 12041da177e4SLinus Torvalds set_fs(KERNEL_DS); 12058feae131SDavid Howells ret = vma->vm_file->f_op->read(vma->vm_file, base, rlen, &fpos); 12061da177e4SLinus Torvalds set_fs(old_fs); 12071da177e4SLinus Torvalds 12081da177e4SLinus Torvalds if (ret < 0) 12091da177e4SLinus Torvalds goto error_free; 12101da177e4SLinus Torvalds 12111da177e4SLinus Torvalds /* clear the last little bit */ 12128feae131SDavid Howells if (ret < rlen) 12138feae131SDavid Howells memset(base + ret, 0, rlen - ret); 12141da177e4SLinus Torvalds 12151da177e4SLinus Torvalds } 12161da177e4SLinus Torvalds 12171da177e4SLinus Torvalds return 0; 12181da177e4SLinus Torvalds 12191da177e4SLinus Torvalds error_free: 12207223bb4aSNamhyung Kim free_page_series(region->vm_start, region->vm_top); 12218feae131SDavid Howells region->vm_start = vma->vm_start = 0; 12228feae131SDavid Howells region->vm_end = vma->vm_end = 0; 1223dd8632a1SPaul Mundt region->vm_top = 0; 12241da177e4SLinus Torvalds return ret; 12251da177e4SLinus Torvalds 12261da177e4SLinus Torvalds enomem: 122705ae6fa3SGreg Ungerer printk("Allocation of length %lu from process %d (%s) failed\n", 122805ae6fa3SGreg Ungerer len, current->pid, current->comm); 12297bf02ea2SDavid Rientjes show_free_areas(0); 12301da177e4SLinus Torvalds return -ENOMEM; 12311da177e4SLinus Torvalds } 12321da177e4SLinus Torvalds 12331da177e4SLinus Torvalds /* 12341da177e4SLinus Torvalds * handle mapping creation for uClinux 12351da177e4SLinus Torvalds */ 12361da177e4SLinus Torvalds unsigned long do_mmap_pgoff(struct file *file, 12371da177e4SLinus Torvalds unsigned long addr, 12381da177e4SLinus Torvalds unsigned long len, 12391da177e4SLinus Torvalds unsigned long prot, 12401da177e4SLinus Torvalds unsigned long flags, 12411da177e4SLinus Torvalds unsigned long pgoff) 12421da177e4SLinus Torvalds { 12438feae131SDavid Howells struct vm_area_struct *vma; 12448feae131SDavid Howells struct vm_region *region; 12451da177e4SLinus Torvalds struct rb_node *rb; 12468feae131SDavid Howells unsigned long capabilities, vm_flags, result; 12471da177e4SLinus Torvalds int ret; 12481da177e4SLinus Torvalds 12498feae131SDavid Howells kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff); 12508feae131SDavid Howells 12511da177e4SLinus Torvalds /* decide whether we should attempt the mapping, and if so what sort of 12521da177e4SLinus Torvalds * mapping */ 12531da177e4SLinus Torvalds ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, 12541da177e4SLinus Torvalds &capabilities); 12558feae131SDavid Howells if (ret < 0) { 12568feae131SDavid Howells kleave(" = %d [val]", ret); 12571da177e4SLinus Torvalds return ret; 12588feae131SDavid Howells } 12591da177e4SLinus Torvalds 126006aab5a3SDavid Howells /* we ignore the address hint */ 126106aab5a3SDavid Howells addr = 0; 126206aab5a3SDavid Howells 12631da177e4SLinus Torvalds /* we've determined that we can make the mapping, now translate what we 12641da177e4SLinus Torvalds * now know into VMA flags */ 12651da177e4SLinus Torvalds vm_flags = determine_vm_flags(file, prot, flags, capabilities); 12661da177e4SLinus Torvalds 12678feae131SDavid Howells /* we're going to need to record the mapping */ 12688feae131SDavid Howells region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); 12698feae131SDavid Howells if (!region) 12708feae131SDavid Howells goto error_getting_region; 12711da177e4SLinus Torvalds 12728feae131SDavid Howells vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); 12738feae131SDavid Howells if (!vma) 12748feae131SDavid Howells goto error_getting_vma; 12751da177e4SLinus Torvalds 12761e2ae599SDavid Howells region->vm_usage = 1; 12778feae131SDavid Howells region->vm_flags = vm_flags; 12788feae131SDavid Howells region->vm_pgoff = pgoff; 12798feae131SDavid Howells 12805beb4930SRik van Riel INIT_LIST_HEAD(&vma->anon_vma_chain); 12818feae131SDavid Howells vma->vm_flags = vm_flags; 12828feae131SDavid Howells vma->vm_pgoff = pgoff; 12838feae131SDavid Howells 12848feae131SDavid Howells if (file) { 12858feae131SDavid Howells region->vm_file = file; 12868feae131SDavid Howells get_file(file); 12878feae131SDavid Howells vma->vm_file = file; 12888feae131SDavid Howells get_file(file); 12898feae131SDavid Howells if (vm_flags & VM_EXECUTABLE) { 12908feae131SDavid Howells added_exe_file_vma(current->mm); 12918feae131SDavid Howells vma->vm_mm = current->mm; 12928feae131SDavid Howells } 12938feae131SDavid Howells } 12948feae131SDavid Howells 12958feae131SDavid Howells down_write(&nommu_region_sem); 12968feae131SDavid Howells 12978feae131SDavid Howells /* if we want to share, we need to check for regions created by other 12981da177e4SLinus Torvalds * mmap() calls that overlap with our proposed mapping 12998feae131SDavid Howells * - we can only share with a superset match on most regular files 13001da177e4SLinus Torvalds * - shared mappings on character devices and memory backed files are 13011da177e4SLinus Torvalds * permitted to overlap inexactly as far as we are concerned for in 13021da177e4SLinus Torvalds * these cases, sharing is handled in the driver or filesystem rather 13031da177e4SLinus Torvalds * than here 13041da177e4SLinus Torvalds */ 13051da177e4SLinus Torvalds if (vm_flags & VM_MAYSHARE) { 13068feae131SDavid Howells struct vm_region *pregion; 13078feae131SDavid Howells unsigned long pglen, rpglen, pgend, rpgend, start; 13081da177e4SLinus Torvalds 13098feae131SDavid Howells pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 13108feae131SDavid Howells pgend = pgoff + pglen; 1311165b2392SDavid Howells 13128feae131SDavid Howells for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { 13138feae131SDavid Howells pregion = rb_entry(rb, struct vm_region, vm_rb); 13141da177e4SLinus Torvalds 13158feae131SDavid Howells if (!(pregion->vm_flags & VM_MAYSHARE)) 13161da177e4SLinus Torvalds continue; 13171da177e4SLinus Torvalds 13181da177e4SLinus Torvalds /* search for overlapping mappings on the same file */ 13198feae131SDavid Howells if (pregion->vm_file->f_path.dentry->d_inode != 13208feae131SDavid Howells file->f_path.dentry->d_inode) 13211da177e4SLinus Torvalds continue; 13221da177e4SLinus Torvalds 13238feae131SDavid Howells if (pregion->vm_pgoff >= pgend) 13241da177e4SLinus Torvalds continue; 13251da177e4SLinus Torvalds 13268feae131SDavid Howells rpglen = pregion->vm_end - pregion->vm_start; 13278feae131SDavid Howells rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; 13288feae131SDavid Howells rpgend = pregion->vm_pgoff + rpglen; 13298feae131SDavid Howells if (pgoff >= rpgend) 13301da177e4SLinus Torvalds continue; 13311da177e4SLinus Torvalds 13328feae131SDavid Howells /* handle inexactly overlapping matches between 13338feae131SDavid Howells * mappings */ 13348feae131SDavid Howells if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && 13358feae131SDavid Howells !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { 13368feae131SDavid Howells /* new mapping is not a subset of the region */ 13371da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_DIRECT)) 13381da177e4SLinus Torvalds goto sharing_violation; 13391da177e4SLinus Torvalds continue; 13401da177e4SLinus Torvalds } 13411da177e4SLinus Torvalds 13428feae131SDavid Howells /* we've found a region we can share */ 13431e2ae599SDavid Howells pregion->vm_usage++; 13448feae131SDavid Howells vma->vm_region = pregion; 13458feae131SDavid Howells start = pregion->vm_start; 13468feae131SDavid Howells start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; 13478feae131SDavid Howells vma->vm_start = start; 13488feae131SDavid Howells vma->vm_end = start + len; 13491da177e4SLinus Torvalds 13508feae131SDavid Howells if (pregion->vm_flags & VM_MAPPED_COPY) { 13518feae131SDavid Howells kdebug("share copy"); 13528feae131SDavid Howells vma->vm_flags |= VM_MAPPED_COPY; 13538feae131SDavid Howells } else { 13548feae131SDavid Howells kdebug("share mmap"); 13558feae131SDavid Howells ret = do_mmap_shared_file(vma); 13568feae131SDavid Howells if (ret < 0) { 13578feae131SDavid Howells vma->vm_region = NULL; 13588feae131SDavid Howells vma->vm_start = 0; 13598feae131SDavid Howells vma->vm_end = 0; 13601e2ae599SDavid Howells pregion->vm_usage--; 13618feae131SDavid Howells pregion = NULL; 13628feae131SDavid Howells goto error_just_free; 13631da177e4SLinus Torvalds } 13648feae131SDavid Howells } 13658feae131SDavid Howells fput(region->vm_file); 13668feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 13678feae131SDavid Howells region = pregion; 13688feae131SDavid Howells result = start; 13698feae131SDavid Howells goto share; 13708feae131SDavid Howells } 13711da177e4SLinus Torvalds 13721da177e4SLinus Torvalds /* obtain the address at which to make a shared mapping 13731da177e4SLinus Torvalds * - this is the hook for quasi-memory character devices to 13741da177e4SLinus Torvalds * tell us the location of a shared mapping 13751da177e4SLinus Torvalds */ 1376645d83c5SDavid Howells if (capabilities & BDI_CAP_MAP_DIRECT) { 13771da177e4SLinus Torvalds addr = file->f_op->get_unmapped_area(file, addr, len, 13781da177e4SLinus Torvalds pgoff, flags); 1379*bb005a59SNamhyung Kim if (IS_ERR_VALUE(addr)) { 13801da177e4SLinus Torvalds ret = addr; 1381*bb005a59SNamhyung Kim if (ret != -ENOSYS) 13828feae131SDavid Howells goto error_just_free; 13831da177e4SLinus Torvalds 13841da177e4SLinus Torvalds /* the driver refused to tell us where to site 13851da177e4SLinus Torvalds * the mapping so we'll have to attempt to copy 13861da177e4SLinus Torvalds * it */ 1387*bb005a59SNamhyung Kim ret = -ENODEV; 13881da177e4SLinus Torvalds if (!(capabilities & BDI_CAP_MAP_COPY)) 13898feae131SDavid Howells goto error_just_free; 13901da177e4SLinus Torvalds 13911da177e4SLinus Torvalds capabilities &= ~BDI_CAP_MAP_DIRECT; 13928feae131SDavid Howells } else { 13938feae131SDavid Howells vma->vm_start = region->vm_start = addr; 13948feae131SDavid Howells vma->vm_end = region->vm_end = addr + len; 13951da177e4SLinus Torvalds } 13961da177e4SLinus Torvalds } 13971da177e4SLinus Torvalds } 13981da177e4SLinus Torvalds 13998feae131SDavid Howells vma->vm_region = region; 14001da177e4SLinus Torvalds 1401645d83c5SDavid Howells /* set up the mapping 1402645d83c5SDavid Howells * - the region is filled in if BDI_CAP_MAP_DIRECT is still set 1403645d83c5SDavid Howells */ 14041da177e4SLinus Torvalds if (file && vma->vm_flags & VM_SHARED) 14058feae131SDavid Howells ret = do_mmap_shared_file(vma); 14061da177e4SLinus Torvalds else 1407645d83c5SDavid Howells ret = do_mmap_private(vma, region, len, capabilities); 14081da177e4SLinus Torvalds if (ret < 0) 1409645d83c5SDavid Howells goto error_just_free; 1410645d83c5SDavid Howells add_nommu_region(region); 14118feae131SDavid Howells 1412ea637639SJie Zhang /* clear anonymous mappings that don't ask for uninitialized data */ 1413ea637639SJie Zhang if (!vma->vm_file && !(flags & MAP_UNINITIALIZED)) 1414ea637639SJie Zhang memset((void *)region->vm_start, 0, 1415ea637639SJie Zhang region->vm_end - region->vm_start); 1416ea637639SJie Zhang 14171da177e4SLinus Torvalds /* okay... we have a mapping; now we have to register it */ 14188feae131SDavid Howells result = vma->vm_start; 14191da177e4SLinus Torvalds 14201da177e4SLinus Torvalds current->mm->total_vm += len >> PAGE_SHIFT; 14211da177e4SLinus Torvalds 14228feae131SDavid Howells share: 14238feae131SDavid Howells add_vma_to_mm(current->mm, vma); 14241da177e4SLinus Torvalds 1425cfe79c00SMike Frysinger /* we flush the region from the icache only when the first executable 1426cfe79c00SMike Frysinger * mapping of it is made */ 1427cfe79c00SMike Frysinger if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { 1428cfe79c00SMike Frysinger flush_icache_range(region->vm_start, region->vm_end); 1429cfe79c00SMike Frysinger region->vm_icache_flushed = true; 1430cfe79c00SMike Frysinger } 14311da177e4SLinus Torvalds 1432cfe79c00SMike Frysinger up_write(&nommu_region_sem); 14331da177e4SLinus Torvalds 14348feae131SDavid Howells kleave(" = %lx", result); 14358feae131SDavid Howells return result; 14361da177e4SLinus Torvalds 14378feae131SDavid Howells error_just_free: 14388feae131SDavid Howells up_write(&nommu_region_sem); 14398feae131SDavid Howells error: 144089a86402SDavid Howells if (region->vm_file) 14418feae131SDavid Howells fput(region->vm_file); 14428feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 144389a86402SDavid Howells if (vma->vm_file) 14448feae131SDavid Howells fput(vma->vm_file); 14458feae131SDavid Howells if (vma->vm_flags & VM_EXECUTABLE) 14468feae131SDavid Howells removed_exe_file_vma(vma->vm_mm); 14478feae131SDavid Howells kmem_cache_free(vm_area_cachep, vma); 14488feae131SDavid Howells kleave(" = %d", ret); 14491da177e4SLinus Torvalds return ret; 14501da177e4SLinus Torvalds 14511da177e4SLinus Torvalds sharing_violation: 14528feae131SDavid Howells up_write(&nommu_region_sem); 14538feae131SDavid Howells printk(KERN_WARNING "Attempt to share mismatched mappings\n"); 14548feae131SDavid Howells ret = -EINVAL; 14558feae131SDavid Howells goto error; 14561da177e4SLinus Torvalds 14571da177e4SLinus Torvalds error_getting_vma: 14588feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 14598feae131SDavid Howells printk(KERN_WARNING "Allocation of vma for %lu byte allocation" 14608feae131SDavid Howells " from process %d failed\n", 14611da177e4SLinus Torvalds len, current->pid); 14627bf02ea2SDavid Rientjes show_free_areas(0); 14631da177e4SLinus Torvalds return -ENOMEM; 14641da177e4SLinus Torvalds 14658feae131SDavid Howells error_getting_region: 14668feae131SDavid Howells printk(KERN_WARNING "Allocation of vm region for %lu byte allocation" 14678feae131SDavid Howells " from process %d failed\n", 14681da177e4SLinus Torvalds len, current->pid); 14697bf02ea2SDavid Rientjes show_free_areas(0); 14701da177e4SLinus Torvalds return -ENOMEM; 14711da177e4SLinus Torvalds } 1472b5073173SPaul Mundt EXPORT_SYMBOL(do_mmap_pgoff); 14731da177e4SLinus Torvalds 147466f0dc48SHugh Dickins SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 147566f0dc48SHugh Dickins unsigned long, prot, unsigned long, flags, 147666f0dc48SHugh Dickins unsigned long, fd, unsigned long, pgoff) 147766f0dc48SHugh Dickins { 147866f0dc48SHugh Dickins struct file *file = NULL; 147966f0dc48SHugh Dickins unsigned long retval = -EBADF; 148066f0dc48SHugh Dickins 1481120a795dSAl Viro audit_mmap_fd(fd, flags); 148266f0dc48SHugh Dickins if (!(flags & MAP_ANONYMOUS)) { 148366f0dc48SHugh Dickins file = fget(fd); 148466f0dc48SHugh Dickins if (!file) 148566f0dc48SHugh Dickins goto out; 148666f0dc48SHugh Dickins } 148766f0dc48SHugh Dickins 148866f0dc48SHugh Dickins flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); 148966f0dc48SHugh Dickins 149066f0dc48SHugh Dickins down_write(¤t->mm->mmap_sem); 149166f0dc48SHugh Dickins retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff); 149266f0dc48SHugh Dickins up_write(¤t->mm->mmap_sem); 149366f0dc48SHugh Dickins 149466f0dc48SHugh Dickins if (file) 149566f0dc48SHugh Dickins fput(file); 149666f0dc48SHugh Dickins out: 149766f0dc48SHugh Dickins return retval; 149866f0dc48SHugh Dickins } 149966f0dc48SHugh Dickins 1500a4679373SChristoph Hellwig #ifdef __ARCH_WANT_SYS_OLD_MMAP 1501a4679373SChristoph Hellwig struct mmap_arg_struct { 1502a4679373SChristoph Hellwig unsigned long addr; 1503a4679373SChristoph Hellwig unsigned long len; 1504a4679373SChristoph Hellwig unsigned long prot; 1505a4679373SChristoph Hellwig unsigned long flags; 1506a4679373SChristoph Hellwig unsigned long fd; 1507a4679373SChristoph Hellwig unsigned long offset; 1508a4679373SChristoph Hellwig }; 1509a4679373SChristoph Hellwig 1510a4679373SChristoph Hellwig SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) 1511a4679373SChristoph Hellwig { 1512a4679373SChristoph Hellwig struct mmap_arg_struct a; 1513a4679373SChristoph Hellwig 1514a4679373SChristoph Hellwig if (copy_from_user(&a, arg, sizeof(a))) 1515a4679373SChristoph Hellwig return -EFAULT; 1516a4679373SChristoph Hellwig if (a.offset & ~PAGE_MASK) 1517a4679373SChristoph Hellwig return -EINVAL; 1518a4679373SChristoph Hellwig 1519a4679373SChristoph Hellwig return sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, 1520a4679373SChristoph Hellwig a.offset >> PAGE_SHIFT); 1521a4679373SChristoph Hellwig } 1522a4679373SChristoph Hellwig #endif /* __ARCH_WANT_SYS_OLD_MMAP */ 1523a4679373SChristoph Hellwig 15241da177e4SLinus Torvalds /* 15258feae131SDavid Howells * split a vma into two pieces at address 'addr', a new vma is allocated either 15268feae131SDavid Howells * for the first part or the tail. 15271da177e4SLinus Torvalds */ 15288feae131SDavid Howells int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 15298feae131SDavid Howells unsigned long addr, int new_below) 15301da177e4SLinus Torvalds { 15318feae131SDavid Howells struct vm_area_struct *new; 15328feae131SDavid Howells struct vm_region *region; 15338feae131SDavid Howells unsigned long npages; 15341da177e4SLinus Torvalds 15358feae131SDavid Howells kenter(""); 15361da177e4SLinus Torvalds 1537779c1023SDavid Howells /* we're only permitted to split anonymous regions (these should have 1538779c1023SDavid Howells * only a single usage on the region) */ 1539779c1023SDavid Howells if (vma->vm_file) 15408feae131SDavid Howells return -ENOMEM; 15411da177e4SLinus Torvalds 15428feae131SDavid Howells if (mm->map_count >= sysctl_max_map_count) 15438feae131SDavid Howells return -ENOMEM; 15441da177e4SLinus Torvalds 15458feae131SDavid Howells region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); 15468feae131SDavid Howells if (!region) 15478feae131SDavid Howells return -ENOMEM; 15488feae131SDavid Howells 15498feae131SDavid Howells new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); 15508feae131SDavid Howells if (!new) { 15518feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 15528feae131SDavid Howells return -ENOMEM; 15531da177e4SLinus Torvalds } 15541da177e4SLinus Torvalds 15558feae131SDavid Howells /* most fields are the same, copy all, and then fixup */ 15568feae131SDavid Howells *new = *vma; 15578feae131SDavid Howells *region = *vma->vm_region; 15588feae131SDavid Howells new->vm_region = region; 15598feae131SDavid Howells 15608feae131SDavid Howells npages = (addr - vma->vm_start) >> PAGE_SHIFT; 15618feae131SDavid Howells 15628feae131SDavid Howells if (new_below) { 1563dd8632a1SPaul Mundt region->vm_top = region->vm_end = new->vm_end = addr; 15648feae131SDavid Howells } else { 15658feae131SDavid Howells region->vm_start = new->vm_start = addr; 15668feae131SDavid Howells region->vm_pgoff = new->vm_pgoff += npages; 15671da177e4SLinus Torvalds } 15688feae131SDavid Howells 15698feae131SDavid Howells if (new->vm_ops && new->vm_ops->open) 15708feae131SDavid Howells new->vm_ops->open(new); 15718feae131SDavid Howells 15728feae131SDavid Howells delete_vma_from_mm(vma); 15738feae131SDavid Howells down_write(&nommu_region_sem); 15748feae131SDavid Howells delete_nommu_region(vma->vm_region); 15758feae131SDavid Howells if (new_below) { 15768feae131SDavid Howells vma->vm_region->vm_start = vma->vm_start = addr; 15778feae131SDavid Howells vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; 15788feae131SDavid Howells } else { 15798feae131SDavid Howells vma->vm_region->vm_end = vma->vm_end = addr; 1580dd8632a1SPaul Mundt vma->vm_region->vm_top = addr; 15818feae131SDavid Howells } 15828feae131SDavid Howells add_nommu_region(vma->vm_region); 15838feae131SDavid Howells add_nommu_region(new->vm_region); 15848feae131SDavid Howells up_write(&nommu_region_sem); 15858feae131SDavid Howells add_vma_to_mm(mm, vma); 15868feae131SDavid Howells add_vma_to_mm(mm, new); 15878feae131SDavid Howells return 0; 15888feae131SDavid Howells } 15898feae131SDavid Howells 15908feae131SDavid Howells /* 15918feae131SDavid Howells * shrink a VMA by removing the specified chunk from either the beginning or 15928feae131SDavid Howells * the end 15938feae131SDavid Howells */ 15948feae131SDavid Howells static int shrink_vma(struct mm_struct *mm, 15958feae131SDavid Howells struct vm_area_struct *vma, 15968feae131SDavid Howells unsigned long from, unsigned long to) 15978feae131SDavid Howells { 15988feae131SDavid Howells struct vm_region *region; 15998feae131SDavid Howells 16008feae131SDavid Howells kenter(""); 16018feae131SDavid Howells 16028feae131SDavid Howells /* adjust the VMA's pointers, which may reposition it in the MM's tree 16038feae131SDavid Howells * and list */ 16048feae131SDavid Howells delete_vma_from_mm(vma); 16058feae131SDavid Howells if (from > vma->vm_start) 16068feae131SDavid Howells vma->vm_end = from; 16078feae131SDavid Howells else 16088feae131SDavid Howells vma->vm_start = to; 16098feae131SDavid Howells add_vma_to_mm(mm, vma); 16108feae131SDavid Howells 16118feae131SDavid Howells /* cut the backing region down to size */ 16128feae131SDavid Howells region = vma->vm_region; 16131e2ae599SDavid Howells BUG_ON(region->vm_usage != 1); 16148feae131SDavid Howells 16158feae131SDavid Howells down_write(&nommu_region_sem); 16168feae131SDavid Howells delete_nommu_region(region); 1617dd8632a1SPaul Mundt if (from > region->vm_start) { 1618dd8632a1SPaul Mundt to = region->vm_top; 1619dd8632a1SPaul Mundt region->vm_top = region->vm_end = from; 1620dd8632a1SPaul Mundt } else { 16218feae131SDavid Howells region->vm_start = to; 1622dd8632a1SPaul Mundt } 16238feae131SDavid Howells add_nommu_region(region); 16248feae131SDavid Howells up_write(&nommu_region_sem); 16258feae131SDavid Howells 16268feae131SDavid Howells free_page_series(from, to); 16278feae131SDavid Howells return 0; 16281da177e4SLinus Torvalds } 16291da177e4SLinus Torvalds 16303034097aSDavid Howells /* 16313034097aSDavid Howells * release a mapping 16328feae131SDavid Howells * - under NOMMU conditions the chunk to be unmapped must be backed by a single 16338feae131SDavid Howells * VMA, though it need not cover the whole VMA 16343034097aSDavid Howells */ 16358feae131SDavid Howells int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) 16361da177e4SLinus Torvalds { 16378feae131SDavid Howells struct vm_area_struct *vma; 16388feae131SDavid Howells unsigned long end = start + len; 16398feae131SDavid Howells int ret; 16401da177e4SLinus Torvalds 16418feae131SDavid Howells kenter(",%lx,%zx", start, len); 16421da177e4SLinus Torvalds 16438feae131SDavid Howells if (len == 0) 16441da177e4SLinus Torvalds return -EINVAL; 16451da177e4SLinus Torvalds 16468feae131SDavid Howells /* find the first potentially overlapping VMA */ 16478feae131SDavid Howells vma = find_vma(mm, start); 16488feae131SDavid Howells if (!vma) { 164933e5d769SDavid Howells static int limit = 0; 165033e5d769SDavid Howells if (limit < 5) { 16518feae131SDavid Howells printk(KERN_WARNING 165233e5d769SDavid Howells "munmap of memory not mmapped by process %d" 165333e5d769SDavid Howells " (%s): 0x%lx-0x%lx\n", 165433e5d769SDavid Howells current->pid, current->comm, 165533e5d769SDavid Howells start, start + len - 1); 165633e5d769SDavid Howells limit++; 165733e5d769SDavid Howells } 16588feae131SDavid Howells return -EINVAL; 16598feae131SDavid Howells } 16601da177e4SLinus Torvalds 16618feae131SDavid Howells /* we're allowed to split an anonymous VMA but not a file-backed one */ 16628feae131SDavid Howells if (vma->vm_file) { 16638feae131SDavid Howells do { 16648feae131SDavid Howells if (start > vma->vm_start) { 16658feae131SDavid Howells kleave(" = -EINVAL [miss]"); 16668feae131SDavid Howells return -EINVAL; 16678feae131SDavid Howells } 16688feae131SDavid Howells if (end == vma->vm_end) 16698feae131SDavid Howells goto erase_whole_vma; 1670d75a310cSNamhyung Kim vma = vma->vm_next; 1671d75a310cSNamhyung Kim } while (vma); 16728feae131SDavid Howells kleave(" = -EINVAL [split file]"); 16738feae131SDavid Howells return -EINVAL; 16748feae131SDavid Howells } else { 16758feae131SDavid Howells /* the chunk must be a subset of the VMA found */ 16768feae131SDavid Howells if (start == vma->vm_start && end == vma->vm_end) 16778feae131SDavid Howells goto erase_whole_vma; 16788feae131SDavid Howells if (start < vma->vm_start || end > vma->vm_end) { 16798feae131SDavid Howells kleave(" = -EINVAL [superset]"); 16808feae131SDavid Howells return -EINVAL; 16818feae131SDavid Howells } 16828feae131SDavid Howells if (start & ~PAGE_MASK) { 16838feae131SDavid Howells kleave(" = -EINVAL [unaligned start]"); 16848feae131SDavid Howells return -EINVAL; 16858feae131SDavid Howells } 16868feae131SDavid Howells if (end != vma->vm_end && end & ~PAGE_MASK) { 16878feae131SDavid Howells kleave(" = -EINVAL [unaligned split]"); 16888feae131SDavid Howells return -EINVAL; 16898feae131SDavid Howells } 16908feae131SDavid Howells if (start != vma->vm_start && end != vma->vm_end) { 16918feae131SDavid Howells ret = split_vma(mm, vma, start, 1); 16928feae131SDavid Howells if (ret < 0) { 16938feae131SDavid Howells kleave(" = %d [split]", ret); 16948feae131SDavid Howells return ret; 16958feae131SDavid Howells } 16968feae131SDavid Howells } 16978feae131SDavid Howells return shrink_vma(mm, vma, start, end); 16988feae131SDavid Howells } 16991da177e4SLinus Torvalds 17008feae131SDavid Howells erase_whole_vma: 17018feae131SDavid Howells delete_vma_from_mm(vma); 17028feae131SDavid Howells delete_vma(mm, vma); 17038feae131SDavid Howells kleave(" = 0"); 17041da177e4SLinus Torvalds return 0; 17051da177e4SLinus Torvalds } 1706b5073173SPaul Mundt EXPORT_SYMBOL(do_munmap); 17071da177e4SLinus Torvalds 17086a6160a7SHeiko Carstens SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) 17093034097aSDavid Howells { 17103034097aSDavid Howells int ret; 17113034097aSDavid Howells struct mm_struct *mm = current->mm; 17123034097aSDavid Howells 17133034097aSDavid Howells down_write(&mm->mmap_sem); 17143034097aSDavid Howells ret = do_munmap(mm, addr, len); 17153034097aSDavid Howells up_write(&mm->mmap_sem); 17163034097aSDavid Howells return ret; 17173034097aSDavid Howells } 17183034097aSDavid Howells 17193034097aSDavid Howells /* 17208feae131SDavid Howells * release all the mappings made in a process's VM space 17213034097aSDavid Howells */ 17221da177e4SLinus Torvalds void exit_mmap(struct mm_struct *mm) 17231da177e4SLinus Torvalds { 17248feae131SDavid Howells struct vm_area_struct *vma; 17251da177e4SLinus Torvalds 17268feae131SDavid Howells if (!mm) 17278feae131SDavid Howells return; 17288feae131SDavid Howells 17298feae131SDavid Howells kenter(""); 17301da177e4SLinus Torvalds 17311da177e4SLinus Torvalds mm->total_vm = 0; 17321da177e4SLinus Torvalds 17338feae131SDavid Howells while ((vma = mm->mmap)) { 17348feae131SDavid Howells mm->mmap = vma->vm_next; 17358feae131SDavid Howells delete_vma_from_mm(vma); 17368feae131SDavid Howells delete_vma(mm, vma); 173704c34961SSteven J. Magnani cond_resched(); 17381da177e4SLinus Torvalds } 17391da177e4SLinus Torvalds 17408feae131SDavid Howells kleave(""); 17411da177e4SLinus Torvalds } 17421da177e4SLinus Torvalds 17431da177e4SLinus Torvalds unsigned long do_brk(unsigned long addr, unsigned long len) 17441da177e4SLinus Torvalds { 17451da177e4SLinus Torvalds return -ENOMEM; 17461da177e4SLinus Torvalds } 17471da177e4SLinus Torvalds 17481da177e4SLinus Torvalds /* 17496fa5f80bSDavid Howells * expand (or shrink) an existing mapping, potentially moving it at the same 17506fa5f80bSDavid Howells * time (controlled by the MREMAP_MAYMOVE flag and available VM space) 17511da177e4SLinus Torvalds * 17526fa5f80bSDavid Howells * under NOMMU conditions, we only permit changing a mapping's size, and only 17538feae131SDavid Howells * as long as it stays within the region allocated by do_mmap_private() and the 17548feae131SDavid Howells * block is not shareable 17551da177e4SLinus Torvalds * 17566fa5f80bSDavid Howells * MREMAP_FIXED is not supported under NOMMU conditions 17571da177e4SLinus Torvalds */ 17581da177e4SLinus Torvalds unsigned long do_mremap(unsigned long addr, 17591da177e4SLinus Torvalds unsigned long old_len, unsigned long new_len, 17601da177e4SLinus Torvalds unsigned long flags, unsigned long new_addr) 17611da177e4SLinus Torvalds { 17626fa5f80bSDavid Howells struct vm_area_struct *vma; 17631da177e4SLinus Torvalds 17641da177e4SLinus Torvalds /* insanity checks first */ 17658feae131SDavid Howells if (old_len == 0 || new_len == 0) 17661da177e4SLinus Torvalds return (unsigned long) -EINVAL; 17671da177e4SLinus Torvalds 17688feae131SDavid Howells if (addr & ~PAGE_MASK) 17698feae131SDavid Howells return -EINVAL; 17708feae131SDavid Howells 17711da177e4SLinus Torvalds if (flags & MREMAP_FIXED && new_addr != addr) 17721da177e4SLinus Torvalds return (unsigned long) -EINVAL; 17731da177e4SLinus Torvalds 17748feae131SDavid Howells vma = find_vma_exact(current->mm, addr, old_len); 17756fa5f80bSDavid Howells if (!vma) 17761da177e4SLinus Torvalds return (unsigned long) -EINVAL; 17771da177e4SLinus Torvalds 17786fa5f80bSDavid Howells if (vma->vm_end != vma->vm_start + old_len) 17791da177e4SLinus Torvalds return (unsigned long) -EFAULT; 17801da177e4SLinus Torvalds 17816fa5f80bSDavid Howells if (vma->vm_flags & VM_MAYSHARE) 17821da177e4SLinus Torvalds return (unsigned long) -EPERM; 17831da177e4SLinus Torvalds 17848feae131SDavid Howells if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) 17851da177e4SLinus Torvalds return (unsigned long) -ENOMEM; 17861da177e4SLinus Torvalds 17871da177e4SLinus Torvalds /* all checks complete - do it */ 17886fa5f80bSDavid Howells vma->vm_end = vma->vm_start + new_len; 17896fa5f80bSDavid Howells return vma->vm_start; 17906fa5f80bSDavid Howells } 1791b5073173SPaul Mundt EXPORT_SYMBOL(do_mremap); 17926fa5f80bSDavid Howells 17936a6160a7SHeiko Carstens SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 17946a6160a7SHeiko Carstens unsigned long, new_len, unsigned long, flags, 17956a6160a7SHeiko Carstens unsigned long, new_addr) 17966fa5f80bSDavid Howells { 17976fa5f80bSDavid Howells unsigned long ret; 17986fa5f80bSDavid Howells 17996fa5f80bSDavid Howells down_write(¤t->mm->mmap_sem); 18006fa5f80bSDavid Howells ret = do_mremap(addr, old_len, new_len, flags, new_addr); 18016fa5f80bSDavid Howells up_write(¤t->mm->mmap_sem); 18026fa5f80bSDavid Howells return ret; 18031da177e4SLinus Torvalds } 18041da177e4SLinus Torvalds 18056aab341eSLinus Torvalds struct page *follow_page(struct vm_area_struct *vma, unsigned long address, 1806deceb6cdSHugh Dickins unsigned int foll_flags) 18071da177e4SLinus Torvalds { 18081da177e4SLinus Torvalds return NULL; 18091da177e4SLinus Torvalds } 18101da177e4SLinus Torvalds 18111da177e4SLinus Torvalds int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, 18121da177e4SLinus Torvalds unsigned long to, unsigned long size, pgprot_t prot) 18131da177e4SLinus Torvalds { 181466aa2b4bSGreg Ungerer vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; 181566aa2b4bSGreg Ungerer return 0; 18161da177e4SLinus Torvalds } 181722c4af40SLuke Yang EXPORT_SYMBOL(remap_pfn_range); 18181da177e4SLinus Torvalds 1819f905bc44SPaul Mundt int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 1820f905bc44SPaul Mundt unsigned long pgoff) 1821f905bc44SPaul Mundt { 1822f905bc44SPaul Mundt unsigned int size = vma->vm_end - vma->vm_start; 1823f905bc44SPaul Mundt 1824f905bc44SPaul Mundt if (!(vma->vm_flags & VM_USERMAP)) 1825f905bc44SPaul Mundt return -EINVAL; 1826f905bc44SPaul Mundt 1827f905bc44SPaul Mundt vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); 1828f905bc44SPaul Mundt vma->vm_end = vma->vm_start + size; 1829f905bc44SPaul Mundt 1830f905bc44SPaul Mundt return 0; 1831f905bc44SPaul Mundt } 1832f905bc44SPaul Mundt EXPORT_SYMBOL(remap_vmalloc_range); 1833f905bc44SPaul Mundt 18341da177e4SLinus Torvalds unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, 18351da177e4SLinus Torvalds unsigned long len, unsigned long pgoff, unsigned long flags) 18361da177e4SLinus Torvalds { 18371da177e4SLinus Torvalds return -ENOMEM; 18381da177e4SLinus Torvalds } 18391da177e4SLinus Torvalds 18401363c3cdSWolfgang Wander void arch_unmap_area(struct mm_struct *mm, unsigned long addr) 18411da177e4SLinus Torvalds { 18421da177e4SLinus Torvalds } 18431da177e4SLinus Torvalds 18441da177e4SLinus Torvalds void unmap_mapping_range(struct address_space *mapping, 18451da177e4SLinus Torvalds loff_t const holebegin, loff_t const holelen, 18461da177e4SLinus Torvalds int even_cows) 18471da177e4SLinus Torvalds { 18481da177e4SLinus Torvalds } 184922c4af40SLuke Yang EXPORT_SYMBOL(unmap_mapping_range); 18501da177e4SLinus Torvalds 18511da177e4SLinus Torvalds /* 18521da177e4SLinus Torvalds * Check that a process has enough memory to allocate a new virtual 18531da177e4SLinus Torvalds * mapping. 0 means there is enough memory for the allocation to 18541da177e4SLinus Torvalds * succeed and -ENOMEM implies there is not. 18551da177e4SLinus Torvalds * 18561da177e4SLinus Torvalds * We currently support three overcommit policies, which are set via the 18571da177e4SLinus Torvalds * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting 18581da177e4SLinus Torvalds * 18591da177e4SLinus Torvalds * Strict overcommit modes added 2002 Feb 26 by Alan Cox. 18601da177e4SLinus Torvalds * Additional code 2002 Jul 20 by Robert Love. 18611da177e4SLinus Torvalds * 18621da177e4SLinus Torvalds * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. 18631da177e4SLinus Torvalds * 18641da177e4SLinus Torvalds * Note this is a helper function intended to be used by LSMs which 18651da177e4SLinus Torvalds * wish to use this logic. 18661da177e4SLinus Torvalds */ 186734b4e4aaSAlan Cox int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) 18681da177e4SLinus Torvalds { 18691da177e4SLinus Torvalds unsigned long free, allowed; 18701da177e4SLinus Torvalds 18711da177e4SLinus Torvalds vm_acct_memory(pages); 18721da177e4SLinus Torvalds 18731da177e4SLinus Torvalds /* 18741da177e4SLinus Torvalds * Sometimes we want to use more memory than we have 18751da177e4SLinus Torvalds */ 18761da177e4SLinus Torvalds if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) 18771da177e4SLinus Torvalds return 0; 18781da177e4SLinus Torvalds 18791da177e4SLinus Torvalds if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { 18801da177e4SLinus Torvalds unsigned long n; 18811da177e4SLinus Torvalds 1882347ce434SChristoph Lameter free = global_page_state(NR_FILE_PAGES); 18831da177e4SLinus Torvalds free += nr_swap_pages; 18841da177e4SLinus Torvalds 18851da177e4SLinus Torvalds /* 18861da177e4SLinus Torvalds * Any slabs which are created with the 18871da177e4SLinus Torvalds * SLAB_RECLAIM_ACCOUNT flag claim to have contents 18881da177e4SLinus Torvalds * which are reclaimable, under pressure. The dentry 18891da177e4SLinus Torvalds * cache and most inode caches should fall into this 18901da177e4SLinus Torvalds */ 1891972d1a7bSChristoph Lameter free += global_page_state(NR_SLAB_RECLAIMABLE); 18921da177e4SLinus Torvalds 18931da177e4SLinus Torvalds /* 18941da177e4SLinus Torvalds * Leave the last 3% for root 18951da177e4SLinus Torvalds */ 18961da177e4SLinus Torvalds if (!cap_sys_admin) 18971da177e4SLinus Torvalds free -= free / 32; 18981da177e4SLinus Torvalds 18991da177e4SLinus Torvalds if (free > pages) 19001da177e4SLinus Torvalds return 0; 19011da177e4SLinus Torvalds 19021da177e4SLinus Torvalds /* 19031da177e4SLinus Torvalds * nr_free_pages() is very expensive on large systems, 19041da177e4SLinus Torvalds * only call if we're about to fail. 19051da177e4SLinus Torvalds */ 19061da177e4SLinus Torvalds n = nr_free_pages(); 1907d5ddc79bSHideo AOKI 1908d5ddc79bSHideo AOKI /* 1909d5ddc79bSHideo AOKI * Leave reserved pages. The pages are not for anonymous pages. 1910d5ddc79bSHideo AOKI */ 1911d5ddc79bSHideo AOKI if (n <= totalreserve_pages) 1912d5ddc79bSHideo AOKI goto error; 1913d5ddc79bSHideo AOKI else 1914d5ddc79bSHideo AOKI n -= totalreserve_pages; 1915d5ddc79bSHideo AOKI 1916d5ddc79bSHideo AOKI /* 1917d5ddc79bSHideo AOKI * Leave the last 3% for root 1918d5ddc79bSHideo AOKI */ 19191da177e4SLinus Torvalds if (!cap_sys_admin) 19201da177e4SLinus Torvalds n -= n / 32; 19211da177e4SLinus Torvalds free += n; 19221da177e4SLinus Torvalds 19231da177e4SLinus Torvalds if (free > pages) 19241da177e4SLinus Torvalds return 0; 1925d5ddc79bSHideo AOKI 1926d5ddc79bSHideo AOKI goto error; 19271da177e4SLinus Torvalds } 19281da177e4SLinus Torvalds 19291da177e4SLinus Torvalds allowed = totalram_pages * sysctl_overcommit_ratio / 100; 19301da177e4SLinus Torvalds /* 19311da177e4SLinus Torvalds * Leave the last 3% for root 19321da177e4SLinus Torvalds */ 19331da177e4SLinus Torvalds if (!cap_sys_admin) 19341da177e4SLinus Torvalds allowed -= allowed / 32; 19351da177e4SLinus Torvalds allowed += total_swap_pages; 19361da177e4SLinus Torvalds 19371da177e4SLinus Torvalds /* Don't let a single process grow too big: 19381da177e4SLinus Torvalds leave 3% of the size of this process for other processes */ 1939731572d3SAlan Cox if (mm) 1940731572d3SAlan Cox allowed -= mm->total_vm / 32; 19411da177e4SLinus Torvalds 194200a62ce9SKOSAKI Motohiro if (percpu_counter_read_positive(&vm_committed_as) < allowed) 19431da177e4SLinus Torvalds return 0; 194400a62ce9SKOSAKI Motohiro 1945d5ddc79bSHideo AOKI error: 19461da177e4SLinus Torvalds vm_unacct_memory(pages); 19471da177e4SLinus Torvalds 19481da177e4SLinus Torvalds return -ENOMEM; 19491da177e4SLinus Torvalds } 19501da177e4SLinus Torvalds 1951cae5d390SStephen Wilson int in_gate_area_no_mm(unsigned long addr) 19521da177e4SLinus Torvalds { 19531da177e4SLinus Torvalds return 0; 19541da177e4SLinus Torvalds } 1955b0e15190SDavid Howells 1956d0217ac0SNick Piggin int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 1957b0e15190SDavid Howells { 1958b0e15190SDavid Howells BUG(); 1959d0217ac0SNick Piggin return 0; 1960b0e15190SDavid Howells } 1961b5073173SPaul Mundt EXPORT_SYMBOL(filemap_fault); 19620ec76a11SDavid Howells 1963f55f199bSMike Frysinger static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, 1964f55f199bSMike Frysinger unsigned long addr, void *buf, int len, int write) 19650ec76a11SDavid Howells { 19660ec76a11SDavid Howells struct vm_area_struct *vma; 19670ec76a11SDavid Howells 19680ec76a11SDavid Howells down_read(&mm->mmap_sem); 19690ec76a11SDavid Howells 19700ec76a11SDavid Howells /* the access must start within one of the target process's mappings */ 19710159b141SDavid Howells vma = find_vma(mm, addr); 19720159b141SDavid Howells if (vma) { 19730ec76a11SDavid Howells /* don't overrun this mapping */ 19740ec76a11SDavid Howells if (addr + len >= vma->vm_end) 19750ec76a11SDavid Howells len = vma->vm_end - addr; 19760ec76a11SDavid Howells 19770ec76a11SDavid Howells /* only read or write mappings where it is permitted */ 1978d00c7b99SDavid Howells if (write && vma->vm_flags & VM_MAYWRITE) 19797959722bSJie Zhang copy_to_user_page(vma, NULL, addr, 19807959722bSJie Zhang (void *) addr, buf, len); 1981d00c7b99SDavid Howells else if (!write && vma->vm_flags & VM_MAYREAD) 19827959722bSJie Zhang copy_from_user_page(vma, NULL, addr, 19837959722bSJie Zhang buf, (void *) addr, len); 19840ec76a11SDavid Howells else 19850ec76a11SDavid Howells len = 0; 19860ec76a11SDavid Howells } else { 19870ec76a11SDavid Howells len = 0; 19880ec76a11SDavid Howells } 19890ec76a11SDavid Howells 19900ec76a11SDavid Howells up_read(&mm->mmap_sem); 1991f55f199bSMike Frysinger 1992f55f199bSMike Frysinger return len; 1993f55f199bSMike Frysinger } 1994f55f199bSMike Frysinger 1995f55f199bSMike Frysinger /** 1996f55f199bSMike Frysinger * @access_remote_vm - access another process' address space 1997f55f199bSMike Frysinger * @mm: the mm_struct of the target address space 1998f55f199bSMike Frysinger * @addr: start address to access 1999f55f199bSMike Frysinger * @buf: source or destination buffer 2000f55f199bSMike Frysinger * @len: number of bytes to transfer 2001f55f199bSMike Frysinger * @write: whether the access is a write 2002f55f199bSMike Frysinger * 2003f55f199bSMike Frysinger * The caller must hold a reference on @mm. 2004f55f199bSMike Frysinger */ 2005f55f199bSMike Frysinger int access_remote_vm(struct mm_struct *mm, unsigned long addr, 2006f55f199bSMike Frysinger void *buf, int len, int write) 2007f55f199bSMike Frysinger { 2008f55f199bSMike Frysinger return __access_remote_vm(NULL, mm, addr, buf, len, write); 2009f55f199bSMike Frysinger } 2010f55f199bSMike Frysinger 2011f55f199bSMike Frysinger /* 2012f55f199bSMike Frysinger * Access another process' address space. 2013f55f199bSMike Frysinger * - source/target buffer must be kernel space 2014f55f199bSMike Frysinger */ 2015f55f199bSMike Frysinger int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) 2016f55f199bSMike Frysinger { 2017f55f199bSMike Frysinger struct mm_struct *mm; 2018f55f199bSMike Frysinger 2019f55f199bSMike Frysinger if (addr + len < addr) 2020f55f199bSMike Frysinger return 0; 2021f55f199bSMike Frysinger 2022f55f199bSMike Frysinger mm = get_task_mm(tsk); 2023f55f199bSMike Frysinger if (!mm) 2024f55f199bSMike Frysinger return 0; 2025f55f199bSMike Frysinger 2026f55f199bSMike Frysinger len = __access_remote_vm(tsk, mm, addr, buf, len, write); 2027f55f199bSMike Frysinger 20280ec76a11SDavid Howells mmput(mm); 20290ec76a11SDavid Howells return len; 20300ec76a11SDavid Howells } 20317e660872SDavid Howells 20327e660872SDavid Howells /** 20337e660872SDavid Howells * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode 20347e660872SDavid Howells * @inode: The inode to check 20357e660872SDavid Howells * @size: The current filesize of the inode 20367e660872SDavid Howells * @newsize: The proposed filesize of the inode 20377e660872SDavid Howells * 20387e660872SDavid Howells * Check the shared mappings on an inode on behalf of a shrinking truncate to 20397e660872SDavid Howells * make sure that that any outstanding VMAs aren't broken and then shrink the 20407e660872SDavid Howells * vm_regions that extend that beyond so that do_mmap_pgoff() doesn't 20417e660872SDavid Howells * automatically grant mappings that are too large. 20427e660872SDavid Howells */ 20437e660872SDavid Howells int nommu_shrink_inode_mappings(struct inode *inode, size_t size, 20447e660872SDavid Howells size_t newsize) 20457e660872SDavid Howells { 20467e660872SDavid Howells struct vm_area_struct *vma; 20477e660872SDavid Howells struct prio_tree_iter iter; 20487e660872SDavid Howells struct vm_region *region; 20497e660872SDavid Howells pgoff_t low, high; 20507e660872SDavid Howells size_t r_size, r_top; 20517e660872SDavid Howells 20527e660872SDavid Howells low = newsize >> PAGE_SHIFT; 20537e660872SDavid Howells high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 20547e660872SDavid Howells 20557e660872SDavid Howells down_write(&nommu_region_sem); 20567e660872SDavid Howells 20577e660872SDavid Howells /* search for VMAs that fall within the dead zone */ 20587e660872SDavid Howells vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap, 20597e660872SDavid Howells low, high) { 20607e660872SDavid Howells /* found one - only interested if it's shared out of the page 20617e660872SDavid Howells * cache */ 20627e660872SDavid Howells if (vma->vm_flags & VM_SHARED) { 20637e660872SDavid Howells up_write(&nommu_region_sem); 20647e660872SDavid Howells return -ETXTBSY; /* not quite true, but near enough */ 20657e660872SDavid Howells } 20667e660872SDavid Howells } 20677e660872SDavid Howells 20687e660872SDavid Howells /* reduce any regions that overlap the dead zone - if in existence, 20697e660872SDavid Howells * these will be pointed to by VMAs that don't overlap the dead zone 20707e660872SDavid Howells * 20717e660872SDavid Howells * we don't check for any regions that start beyond the EOF as there 20727e660872SDavid Howells * shouldn't be any 20737e660872SDavid Howells */ 20747e660872SDavid Howells vma_prio_tree_foreach(vma, &iter, &inode->i_mapping->i_mmap, 20757e660872SDavid Howells 0, ULONG_MAX) { 20767e660872SDavid Howells if (!(vma->vm_flags & VM_SHARED)) 20777e660872SDavid Howells continue; 20787e660872SDavid Howells 20797e660872SDavid Howells region = vma->vm_region; 20807e660872SDavid Howells r_size = region->vm_top - region->vm_start; 20817e660872SDavid Howells r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; 20827e660872SDavid Howells 20837e660872SDavid Howells if (r_top > newsize) { 20847e660872SDavid Howells region->vm_top -= r_top - newsize; 20857e660872SDavid Howells if (region->vm_end > region->vm_top) 20867e660872SDavid Howells region->vm_end = region->vm_top; 20877e660872SDavid Howells } 20887e660872SDavid Howells } 20897e660872SDavid Howells 20907e660872SDavid Howells up_write(&nommu_region_sem); 20917e660872SDavid Howells return 0; 20927e660872SDavid Howells } 2093