1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/mm/nommu.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Replacement code for mm functions to support CPU's that don't 61da177e4SLinus Torvalds * have any form of memory management unit (thus no virtual memory). 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * See Documentation/nommu-mmap.txt 91da177e4SLinus Torvalds * 108feae131SDavid Howells * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com> 111da177e4SLinus Torvalds * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> 121da177e4SLinus Torvalds * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> 131da177e4SLinus Torvalds * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> 1429c185e5SPaul Mundt * Copyright (c) 2007-2010 Paul Mundt <lethal@linux-sh.org> 151da177e4SLinus Torvalds */ 161da177e4SLinus Torvalds 17b1de0d13SMitchel Humpherys #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18b1de0d13SMitchel Humpherys 19b95f1b31SPaul Gortmaker #include <linux/export.h> 201da177e4SLinus Torvalds #include <linux/mm.h> 216e84f315SIngo Molnar #include <linux/sched/mm.h> 22615d6e87SDavidlohr Bueso #include <linux/vmacache.h> 231da177e4SLinus Torvalds #include <linux/mman.h> 241da177e4SLinus Torvalds #include <linux/swap.h> 251da177e4SLinus Torvalds #include <linux/file.h> 261da177e4SLinus Torvalds #include <linux/highmem.h> 271da177e4SLinus Torvalds #include <linux/pagemap.h> 281da177e4SLinus Torvalds #include <linux/slab.h> 291da177e4SLinus Torvalds #include <linux/vmalloc.h> 301da177e4SLinus Torvalds #include <linux/blkdev.h> 311da177e4SLinus Torvalds #include <linux/backing-dev.h> 323b32123dSGideon Israel Dsouza #include <linux/compiler.h> 331da177e4SLinus Torvalds #include <linux/mount.h> 341da177e4SLinus Torvalds #include <linux/personality.h> 351da177e4SLinus Torvalds #include <linux/security.h> 361da177e4SLinus Torvalds #include <linux/syscalls.h> 37120a795dSAl Viro #include <linux/audit.h> 38b1de0d13SMitchel Humpherys #include <linux/printk.h> 391da177e4SLinus Torvalds 407c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 411da177e4SLinus Torvalds #include <asm/tlb.h> 421da177e4SLinus Torvalds #include <asm/tlbflush.h> 43eb8cdec4SBernd Schmidt #include <asm/mmu_context.h> 448feae131SDavid Howells #include "internal.h" 458feae131SDavid Howells 461da177e4SLinus Torvalds void *high_memory; 47944b6874SArnd Bergmann EXPORT_SYMBOL(high_memory); 481da177e4SLinus Torvalds struct page *mem_map; 491da177e4SLinus Torvalds unsigned long max_mapnr; 505b8bf307Sgchen gchen EXPORT_SYMBOL(max_mapnr); 514266c97aSHugh Dickins unsigned long highest_memmap_pfn; 52fc4d5c29SDavid Howells int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; 531da177e4SLinus Torvalds int heap_stack_gap = 0; 541da177e4SLinus Torvalds 5533e5d769SDavid Howells atomic_long_t mmap_pages_allocated; 568feae131SDavid Howells 571da177e4SLinus Torvalds EXPORT_SYMBOL(mem_map); 581da177e4SLinus Torvalds 598feae131SDavid Howells /* list of mapped, potentially shareable regions */ 608feae131SDavid Howells static struct kmem_cache *vm_region_jar; 618feae131SDavid Howells struct rb_root nommu_region_tree = RB_ROOT; 628feae131SDavid Howells DECLARE_RWSEM(nommu_region_sem); 631da177e4SLinus Torvalds 64f0f37e2fSAlexey Dobriyan const struct vm_operations_struct generic_file_vm_ops = { 651da177e4SLinus Torvalds }; 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds /* 681da177e4SLinus Torvalds * Return the total memory allocated for this pointer, not 691da177e4SLinus Torvalds * just what the caller asked for. 701da177e4SLinus Torvalds * 711da177e4SLinus Torvalds * Doesn't have to be accurate, i.e. may have races. 721da177e4SLinus Torvalds */ 731da177e4SLinus Torvalds unsigned int kobjsize(const void *objp) 741da177e4SLinus Torvalds { 751da177e4SLinus Torvalds struct page *page; 761da177e4SLinus Torvalds 774016a139SMichael Hennerich /* 784016a139SMichael Hennerich * If the object we have should not have ksize performed on it, 794016a139SMichael Hennerich * return size of 0 804016a139SMichael Hennerich */ 815a1603beSPaul Mundt if (!objp || !virt_addr_valid(objp)) 826cfd53fcSPaul Mundt return 0; 836cfd53fcSPaul Mundt 846cfd53fcSPaul Mundt page = virt_to_head_page(objp); 856cfd53fcSPaul Mundt 866cfd53fcSPaul Mundt /* 876cfd53fcSPaul Mundt * If the allocator sets PageSlab, we know the pointer came from 886cfd53fcSPaul Mundt * kmalloc(). 896cfd53fcSPaul Mundt */ 901da177e4SLinus Torvalds if (PageSlab(page)) 911da177e4SLinus Torvalds return ksize(objp); 921da177e4SLinus Torvalds 936cfd53fcSPaul Mundt /* 94ab2e83eaSPaul Mundt * If it's not a compound page, see if we have a matching VMA 95ab2e83eaSPaul Mundt * region. This test is intentionally done in reverse order, 96ab2e83eaSPaul Mundt * so if there's no VMA, we still fall through and hand back 97ab2e83eaSPaul Mundt * PAGE_SIZE for 0-order pages. 98ab2e83eaSPaul Mundt */ 99ab2e83eaSPaul Mundt if (!PageCompound(page)) { 100ab2e83eaSPaul Mundt struct vm_area_struct *vma; 101ab2e83eaSPaul Mundt 102ab2e83eaSPaul Mundt vma = find_vma(current->mm, (unsigned long)objp); 103ab2e83eaSPaul Mundt if (vma) 104ab2e83eaSPaul Mundt return vma->vm_end - vma->vm_start; 105ab2e83eaSPaul Mundt } 106ab2e83eaSPaul Mundt 107ab2e83eaSPaul Mundt /* 1086cfd53fcSPaul Mundt * The ksize() function is only guaranteed to work for pointers 1095a1603beSPaul Mundt * returned by kmalloc(). So handle arbitrary pointers here. 1106cfd53fcSPaul Mundt */ 111a50b854eSMatthew Wilcox (Oracle) return page_size(page); 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds 114dfc2f91aSPaul Mundt /** 115dfc2f91aSPaul Mundt * follow_pfn - look up PFN at a user virtual address 116dfc2f91aSPaul Mundt * @vma: memory mapping 117dfc2f91aSPaul Mundt * @address: user virtual address 118dfc2f91aSPaul Mundt * @pfn: location to store found PFN 119dfc2f91aSPaul Mundt * 120dfc2f91aSPaul Mundt * Only IO mappings and raw PFN mappings are allowed. 121dfc2f91aSPaul Mundt * 122dfc2f91aSPaul Mundt * Returns zero and the pfn at @pfn on success, -ve otherwise. 123dfc2f91aSPaul Mundt */ 124dfc2f91aSPaul Mundt int follow_pfn(struct vm_area_struct *vma, unsigned long address, 125dfc2f91aSPaul Mundt unsigned long *pfn) 126dfc2f91aSPaul Mundt { 127dfc2f91aSPaul Mundt if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 128dfc2f91aSPaul Mundt return -EINVAL; 129dfc2f91aSPaul Mundt 130dfc2f91aSPaul Mundt *pfn = address >> PAGE_SHIFT; 131dfc2f91aSPaul Mundt return 0; 132dfc2f91aSPaul Mundt } 133dfc2f91aSPaul Mundt EXPORT_SYMBOL(follow_pfn); 134dfc2f91aSPaul Mundt 135f1c4069eSJoonsoo Kim LIST_HEAD(vmap_area_list); 1361da177e4SLinus Torvalds 137b3bdda02SChristoph Lameter void vfree(const void *addr) 1381da177e4SLinus Torvalds { 1391da177e4SLinus Torvalds kfree(addr); 1401da177e4SLinus Torvalds } 141b5073173SPaul Mundt EXPORT_SYMBOL(vfree); 1421da177e4SLinus Torvalds 143dd0fc66fSAl Viro void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) 1441da177e4SLinus Torvalds { 1451da177e4SLinus Torvalds /* 1468518609dSRobert P. J. Day * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() 1478518609dSRobert P. J. Day * returns only a logical address. 1481da177e4SLinus Torvalds */ 14984097518SNick Piggin return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); 1501da177e4SLinus Torvalds } 151b5073173SPaul Mundt EXPORT_SYMBOL(__vmalloc); 1521da177e4SLinus Torvalds 153a7c3e901SMichal Hocko void *__vmalloc_node_flags(unsigned long size, int node, gfp_t flags) 154a7c3e901SMichal Hocko { 155a7c3e901SMichal Hocko return __vmalloc(size, flags, PAGE_KERNEL); 156a7c3e901SMichal Hocko } 157a7c3e901SMichal Hocko 158*ed81745aSAndrii Nakryiko static void *__vmalloc_user_flags(unsigned long size, gfp_t flags) 159f905bc44SPaul Mundt { 160f905bc44SPaul Mundt void *ret; 161f905bc44SPaul Mundt 162*ed81745aSAndrii Nakryiko ret = __vmalloc(size, flags, PAGE_KERNEL); 163f905bc44SPaul Mundt if (ret) { 164f905bc44SPaul Mundt struct vm_area_struct *vma; 165f905bc44SPaul Mundt 166f905bc44SPaul Mundt down_write(¤t->mm->mmap_sem); 167f905bc44SPaul Mundt vma = find_vma(current->mm, (unsigned long)ret); 168f905bc44SPaul Mundt if (vma) 169f905bc44SPaul Mundt vma->vm_flags |= VM_USERMAP; 170f905bc44SPaul Mundt up_write(¤t->mm->mmap_sem); 171f905bc44SPaul Mundt } 172f905bc44SPaul Mundt 173f905bc44SPaul Mundt return ret; 174f905bc44SPaul Mundt } 175*ed81745aSAndrii Nakryiko 176*ed81745aSAndrii Nakryiko void *vmalloc_user(unsigned long size) 177*ed81745aSAndrii Nakryiko { 178*ed81745aSAndrii Nakryiko return __vmalloc_user_flags(size, GFP_KERNEL | __GFP_ZERO); 179*ed81745aSAndrii Nakryiko } 180f905bc44SPaul Mundt EXPORT_SYMBOL(vmalloc_user); 181f905bc44SPaul Mundt 182*ed81745aSAndrii Nakryiko void *vmalloc_user_node_flags(unsigned long size, int node, gfp_t flags) 183*ed81745aSAndrii Nakryiko { 184*ed81745aSAndrii Nakryiko return __vmalloc_user_flags(size, flags | __GFP_ZERO); 185*ed81745aSAndrii Nakryiko } 186*ed81745aSAndrii Nakryiko EXPORT_SYMBOL(vmalloc_user_node_flags); 187*ed81745aSAndrii Nakryiko 188b3bdda02SChristoph Lameter struct page *vmalloc_to_page(const void *addr) 1891da177e4SLinus Torvalds { 1901da177e4SLinus Torvalds return virt_to_page(addr); 1911da177e4SLinus Torvalds } 192b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_page); 1931da177e4SLinus Torvalds 194b3bdda02SChristoph Lameter unsigned long vmalloc_to_pfn(const void *addr) 1951da177e4SLinus Torvalds { 1961da177e4SLinus Torvalds return page_to_pfn(virt_to_page(addr)); 1971da177e4SLinus Torvalds } 198b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_pfn); 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds long vread(char *buf, char *addr, unsigned long count) 2011da177e4SLinus Torvalds { 2029bde916bSChen Gang /* Don't allow overflow */ 2039bde916bSChen Gang if ((unsigned long) buf + count < count) 2049bde916bSChen Gang count = -(unsigned long) buf; 2059bde916bSChen Gang 2061da177e4SLinus Torvalds memcpy(buf, addr, count); 2071da177e4SLinus Torvalds return count; 2081da177e4SLinus Torvalds } 2091da177e4SLinus Torvalds 2101da177e4SLinus Torvalds long vwrite(char *buf, char *addr, unsigned long count) 2111da177e4SLinus Torvalds { 2121da177e4SLinus Torvalds /* Don't allow overflow */ 2131da177e4SLinus Torvalds if ((unsigned long) addr + count < count) 2141da177e4SLinus Torvalds count = -(unsigned long) addr; 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds memcpy(addr, buf, count); 217ac714904SChoi Gi-yong return count; 2181da177e4SLinus Torvalds } 2191da177e4SLinus Torvalds 2201da177e4SLinus Torvalds /* 221e1c05067SMasahiro Yamada * vmalloc - allocate virtually contiguous memory 2221da177e4SLinus Torvalds * 2231da177e4SLinus Torvalds * @size: allocation size 2241da177e4SLinus Torvalds * 2251da177e4SLinus Torvalds * Allocate enough pages to cover @size from the page level 226e1c05067SMasahiro Yamada * allocator and map them into contiguous kernel virtual space. 2271da177e4SLinus Torvalds * 228c1c8897fSMichael Opdenacker * For tight control over page level allocator and protection flags 2291da177e4SLinus Torvalds * use __vmalloc() instead. 2301da177e4SLinus Torvalds */ 2311da177e4SLinus Torvalds void *vmalloc(unsigned long size) 2321da177e4SLinus Torvalds { 2331da177e4SLinus Torvalds return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); 2341da177e4SLinus Torvalds } 235f6138882SAndrew Morton EXPORT_SYMBOL(vmalloc); 236f6138882SAndrew Morton 237e1ca7788SDave Young /* 238e1c05067SMasahiro Yamada * vzalloc - allocate virtually contiguous memory with zero fill 239e1ca7788SDave Young * 240e1ca7788SDave Young * @size: allocation size 241e1ca7788SDave Young * 242e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 243e1c05067SMasahiro Yamada * allocator and map them into contiguous kernel virtual space. 244e1ca7788SDave Young * The memory allocated is set to zero. 245e1ca7788SDave Young * 246e1ca7788SDave Young * For tight control over page level allocator and protection flags 247e1ca7788SDave Young * use __vmalloc() instead. 248e1ca7788SDave Young */ 249e1ca7788SDave Young void *vzalloc(unsigned long size) 250e1ca7788SDave Young { 251e1ca7788SDave Young return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, 252e1ca7788SDave Young PAGE_KERNEL); 253e1ca7788SDave Young } 254e1ca7788SDave Young EXPORT_SYMBOL(vzalloc); 255e1ca7788SDave Young 256e1ca7788SDave Young /** 257e1ca7788SDave Young * vmalloc_node - allocate memory on a specific node 258e1ca7788SDave Young * @size: allocation size 259e1ca7788SDave Young * @node: numa node 260e1ca7788SDave Young * 261e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 262e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 263e1ca7788SDave Young * 264e1ca7788SDave Young * For tight control over page level allocator and protection flags 265e1ca7788SDave Young * use __vmalloc() instead. 266e1ca7788SDave Young */ 267f6138882SAndrew Morton void *vmalloc_node(unsigned long size, int node) 268f6138882SAndrew Morton { 269f6138882SAndrew Morton return vmalloc(size); 270f6138882SAndrew Morton } 2719a14f653SPaul Mundt EXPORT_SYMBOL(vmalloc_node); 272e1ca7788SDave Young 273e1ca7788SDave Young /** 274e1ca7788SDave Young * vzalloc_node - allocate memory on a specific node with zero fill 275e1ca7788SDave Young * @size: allocation size 276e1ca7788SDave Young * @node: numa node 277e1ca7788SDave Young * 278e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 279e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 280e1ca7788SDave Young * The memory allocated is set to zero. 281e1ca7788SDave Young * 282e1ca7788SDave Young * For tight control over page level allocator and protection flags 283e1ca7788SDave Young * use __vmalloc() instead. 284e1ca7788SDave Young */ 285e1ca7788SDave Young void *vzalloc_node(unsigned long size, int node) 286e1ca7788SDave Young { 287e1ca7788SDave Young return vzalloc(size); 288e1ca7788SDave Young } 289e1ca7788SDave Young EXPORT_SYMBOL(vzalloc_node); 2901da177e4SLinus Torvalds 2911af446edSPaul Mundt /** 2921af446edSPaul Mundt * vmalloc_exec - allocate virtually contiguous, executable memory 2931af446edSPaul Mundt * @size: allocation size 2941af446edSPaul Mundt * 2951af446edSPaul Mundt * Kernel-internal function to allocate enough pages to cover @size 2961af446edSPaul Mundt * the page level allocator and map them into contiguous and 2971af446edSPaul Mundt * executable kernel virtual space. 2981af446edSPaul Mundt * 2991af446edSPaul Mundt * For tight control over page level allocator and protection flags 3001af446edSPaul Mundt * use __vmalloc() instead. 3011af446edSPaul Mundt */ 3021af446edSPaul Mundt 3031af446edSPaul Mundt void *vmalloc_exec(unsigned long size) 3041af446edSPaul Mundt { 3051af446edSPaul Mundt return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); 3061af446edSPaul Mundt } 3071af446edSPaul Mundt 308b5073173SPaul Mundt /** 309b5073173SPaul Mundt * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 3101da177e4SLinus Torvalds * @size: allocation size 3111da177e4SLinus Torvalds * 3121da177e4SLinus Torvalds * Allocate enough 32bit PA addressable pages to cover @size from the 313e1c05067SMasahiro Yamada * page level allocator and map them into contiguous kernel virtual space. 3141da177e4SLinus Torvalds */ 3151da177e4SLinus Torvalds void *vmalloc_32(unsigned long size) 3161da177e4SLinus Torvalds { 3171da177e4SLinus Torvalds return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); 3181da177e4SLinus Torvalds } 319b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32); 320b5073173SPaul Mundt 321b5073173SPaul Mundt /** 322b5073173SPaul Mundt * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 323b5073173SPaul Mundt * @size: allocation size 324b5073173SPaul Mundt * 325b5073173SPaul Mundt * The resulting memory area is 32bit addressable and zeroed so it can be 326b5073173SPaul Mundt * mapped to userspace without leaking data. 327f905bc44SPaul Mundt * 328f905bc44SPaul Mundt * VM_USERMAP is set on the corresponding VMA so that subsequent calls to 329f905bc44SPaul Mundt * remap_vmalloc_range() are permissible. 330b5073173SPaul Mundt */ 331b5073173SPaul Mundt void *vmalloc_32_user(unsigned long size) 332b5073173SPaul Mundt { 333f905bc44SPaul Mundt /* 334f905bc44SPaul Mundt * We'll have to sort out the ZONE_DMA bits for 64-bit, 335f905bc44SPaul Mundt * but for now this can simply use vmalloc_user() directly. 336f905bc44SPaul Mundt */ 337f905bc44SPaul Mundt return vmalloc_user(size); 338b5073173SPaul Mundt } 339b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32_user); 3401da177e4SLinus Torvalds 3411da177e4SLinus Torvalds void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) 3421da177e4SLinus Torvalds { 3431da177e4SLinus Torvalds BUG(); 3441da177e4SLinus Torvalds return NULL; 3451da177e4SLinus Torvalds } 346b5073173SPaul Mundt EXPORT_SYMBOL(vmap); 3471da177e4SLinus Torvalds 348b3bdda02SChristoph Lameter void vunmap(const void *addr) 3491da177e4SLinus Torvalds { 3501da177e4SLinus Torvalds BUG(); 3511da177e4SLinus Torvalds } 352b5073173SPaul Mundt EXPORT_SYMBOL(vunmap); 3531da177e4SLinus Torvalds 354eb6434d9SPaul Mundt void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) 355eb6434d9SPaul Mundt { 356eb6434d9SPaul Mundt BUG(); 357eb6434d9SPaul Mundt return NULL; 358eb6434d9SPaul Mundt } 359eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_map_ram); 360eb6434d9SPaul Mundt 361eb6434d9SPaul Mundt void vm_unmap_ram(const void *mem, unsigned int count) 362eb6434d9SPaul Mundt { 363eb6434d9SPaul Mundt BUG(); 364eb6434d9SPaul Mundt } 365eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_unmap_ram); 366eb6434d9SPaul Mundt 367eb6434d9SPaul Mundt void vm_unmap_aliases(void) 368eb6434d9SPaul Mundt { 369eb6434d9SPaul Mundt } 370eb6434d9SPaul Mundt EXPORT_SYMBOL_GPL(vm_unmap_aliases); 371eb6434d9SPaul Mundt 3721da177e4SLinus Torvalds /* 3731eeb66a1SChristoph Hellwig * Implement a stub for vmalloc_sync_all() if the architecture chose not to 3741eeb66a1SChristoph Hellwig * have one. 3751eeb66a1SChristoph Hellwig */ 3763b32123dSGideon Israel Dsouza void __weak vmalloc_sync_all(void) 3771eeb66a1SChristoph Hellwig { 3781eeb66a1SChristoph Hellwig } 3791eeb66a1SChristoph Hellwig 380cd12909cSDavid Vrabel struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) 38129c185e5SPaul Mundt { 38229c185e5SPaul Mundt BUG(); 38329c185e5SPaul Mundt return NULL; 38429c185e5SPaul Mundt } 38529c185e5SPaul Mundt EXPORT_SYMBOL_GPL(alloc_vm_area); 38629c185e5SPaul Mundt 38729c185e5SPaul Mundt void free_vm_area(struct vm_struct *area) 38829c185e5SPaul Mundt { 38929c185e5SPaul Mundt BUG(); 39029c185e5SPaul Mundt } 39129c185e5SPaul Mundt EXPORT_SYMBOL_GPL(free_vm_area); 39229c185e5SPaul Mundt 393b5073173SPaul Mundt int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 394b5073173SPaul Mundt struct page *page) 395b5073173SPaul Mundt { 396b5073173SPaul Mundt return -EINVAL; 397b5073173SPaul Mundt } 398b5073173SPaul Mundt EXPORT_SYMBOL(vm_insert_page); 399b5073173SPaul Mundt 400a667d745SSouptick Joarder int vm_map_pages(struct vm_area_struct *vma, struct page **pages, 401a667d745SSouptick Joarder unsigned long num) 402a667d745SSouptick Joarder { 403a667d745SSouptick Joarder return -EINVAL; 404a667d745SSouptick Joarder } 405a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages); 406a667d745SSouptick Joarder 407a667d745SSouptick Joarder int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, 408a667d745SSouptick Joarder unsigned long num) 409a667d745SSouptick Joarder { 410a667d745SSouptick Joarder return -EINVAL; 411a667d745SSouptick Joarder } 412a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages_zero); 413a667d745SSouptick Joarder 4141eeb66a1SChristoph Hellwig /* 4151da177e4SLinus Torvalds * sys_brk() for the most part doesn't need the global kernel 4161da177e4SLinus Torvalds * lock, except when an application is doing something nasty 4171da177e4SLinus Torvalds * like trying to un-brk an area that has already been mapped 4181da177e4SLinus Torvalds * to a regular file. in this case, the unmapping will need 4191da177e4SLinus Torvalds * to invoke file system routines that need the global lock. 4201da177e4SLinus Torvalds */ 4216a6160a7SHeiko Carstens SYSCALL_DEFINE1(brk, unsigned long, brk) 4221da177e4SLinus Torvalds { 4231da177e4SLinus Torvalds struct mm_struct *mm = current->mm; 4241da177e4SLinus Torvalds 4251da177e4SLinus Torvalds if (brk < mm->start_brk || brk > mm->context.end_brk) 4261da177e4SLinus Torvalds return mm->brk; 4271da177e4SLinus Torvalds 4281da177e4SLinus Torvalds if (mm->brk == brk) 4291da177e4SLinus Torvalds return mm->brk; 4301da177e4SLinus Torvalds 4311da177e4SLinus Torvalds /* 4321da177e4SLinus Torvalds * Always allow shrinking brk 4331da177e4SLinus Torvalds */ 4341da177e4SLinus Torvalds if (brk <= mm->brk) { 4351da177e4SLinus Torvalds mm->brk = brk; 4361da177e4SLinus Torvalds return brk; 4371da177e4SLinus Torvalds } 4381da177e4SLinus Torvalds 4391da177e4SLinus Torvalds /* 4401da177e4SLinus Torvalds * Ok, looks good - let it rip. 4411da177e4SLinus Torvalds */ 442cfe79c00SMike Frysinger flush_icache_range(mm->brk, brk); 4431da177e4SLinus Torvalds return mm->brk = brk; 4441da177e4SLinus Torvalds } 4451da177e4SLinus Torvalds 4468feae131SDavid Howells /* 4473edf41d8Sseokhoon.yoon * initialise the percpu counter for VM and region record slabs 4488feae131SDavid Howells */ 4498feae131SDavid Howells void __init mmap_init(void) 4501da177e4SLinus Torvalds { 45100a62ce9SKOSAKI Motohiro int ret; 45200a62ce9SKOSAKI Motohiro 453908c7f19STejun Heo ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); 45400a62ce9SKOSAKI Motohiro VM_BUG_ON(ret); 4555d097056SVladimir Davydov vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC|SLAB_ACCOUNT); 4568feae131SDavid Howells } 4571da177e4SLinus Torvalds 4588feae131SDavid Howells /* 4598feae131SDavid Howells * validate the region tree 4608feae131SDavid Howells * - the caller must hold the region lock 4618feae131SDavid Howells */ 4628feae131SDavid Howells #ifdef CONFIG_DEBUG_NOMMU_REGIONS 4638feae131SDavid Howells static noinline void validate_nommu_regions(void) 4648feae131SDavid Howells { 4658feae131SDavid Howells struct vm_region *region, *last; 4668feae131SDavid Howells struct rb_node *p, *lastp; 4671da177e4SLinus Torvalds 4688feae131SDavid Howells lastp = rb_first(&nommu_region_tree); 4698feae131SDavid Howells if (!lastp) 4708feae131SDavid Howells return; 4718feae131SDavid Howells 4728feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 473c9427bc0SGeliang Tang BUG_ON(last->vm_end <= last->vm_start); 474c9427bc0SGeliang Tang BUG_ON(last->vm_top < last->vm_end); 4758feae131SDavid Howells 4768feae131SDavid Howells while ((p = rb_next(lastp))) { 4778feae131SDavid Howells region = rb_entry(p, struct vm_region, vm_rb); 4788feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 4798feae131SDavid Howells 480c9427bc0SGeliang Tang BUG_ON(region->vm_end <= region->vm_start); 481c9427bc0SGeliang Tang BUG_ON(region->vm_top < region->vm_end); 482c9427bc0SGeliang Tang BUG_ON(region->vm_start < last->vm_top); 4838feae131SDavid Howells 4848feae131SDavid Howells lastp = p; 4851da177e4SLinus Torvalds } 4861da177e4SLinus Torvalds } 4878feae131SDavid Howells #else 48833e5d769SDavid Howells static void validate_nommu_regions(void) 48933e5d769SDavid Howells { 49033e5d769SDavid Howells } 4918feae131SDavid Howells #endif 4928feae131SDavid Howells 4938feae131SDavid Howells /* 4948feae131SDavid Howells * add a region into the global tree 4958feae131SDavid Howells */ 4968feae131SDavid Howells static void add_nommu_region(struct vm_region *region) 4978feae131SDavid Howells { 4988feae131SDavid Howells struct vm_region *pregion; 4998feae131SDavid Howells struct rb_node **p, *parent; 5008feae131SDavid Howells 5018feae131SDavid Howells validate_nommu_regions(); 5028feae131SDavid Howells 5038feae131SDavid Howells parent = NULL; 5048feae131SDavid Howells p = &nommu_region_tree.rb_node; 5058feae131SDavid Howells while (*p) { 5068feae131SDavid Howells parent = *p; 5078feae131SDavid Howells pregion = rb_entry(parent, struct vm_region, vm_rb); 5088feae131SDavid Howells if (region->vm_start < pregion->vm_start) 5098feae131SDavid Howells p = &(*p)->rb_left; 5108feae131SDavid Howells else if (region->vm_start > pregion->vm_start) 5118feae131SDavid Howells p = &(*p)->rb_right; 5128feae131SDavid Howells else if (pregion == region) 5138feae131SDavid Howells return; 5148feae131SDavid Howells else 5158feae131SDavid Howells BUG(); 5168feae131SDavid Howells } 5178feae131SDavid Howells 5188feae131SDavid Howells rb_link_node(®ion->vm_rb, parent, p); 5198feae131SDavid Howells rb_insert_color(®ion->vm_rb, &nommu_region_tree); 5208feae131SDavid Howells 5218feae131SDavid Howells validate_nommu_regions(); 5228feae131SDavid Howells } 5238feae131SDavid Howells 5248feae131SDavid Howells /* 5258feae131SDavid Howells * delete a region from the global tree 5268feae131SDavid Howells */ 5278feae131SDavid Howells static void delete_nommu_region(struct vm_region *region) 5288feae131SDavid Howells { 5298feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5308feae131SDavid Howells 5318feae131SDavid Howells validate_nommu_regions(); 5328feae131SDavid Howells rb_erase(®ion->vm_rb, &nommu_region_tree); 5338feae131SDavid Howells validate_nommu_regions(); 5348feae131SDavid Howells } 5358feae131SDavid Howells 5368feae131SDavid Howells /* 5378feae131SDavid Howells * free a contiguous series of pages 5388feae131SDavid Howells */ 5398feae131SDavid Howells static void free_page_series(unsigned long from, unsigned long to) 5408feae131SDavid Howells { 5418feae131SDavid Howells for (; from < to; from += PAGE_SIZE) { 5428feae131SDavid Howells struct page *page = virt_to_page(from); 5438feae131SDavid Howells 54433e5d769SDavid Howells atomic_long_dec(&mmap_pages_allocated); 5458feae131SDavid Howells put_page(page); 5468feae131SDavid Howells } 5478feae131SDavid Howells } 5488feae131SDavid Howells 5498feae131SDavid Howells /* 5508feae131SDavid Howells * release a reference to a region 55133e5d769SDavid Howells * - the caller must hold the region semaphore for writing, which this releases 552dd8632a1SPaul Mundt * - the region may not have been added to the tree yet, in which case vm_top 5538feae131SDavid Howells * will equal vm_start 5548feae131SDavid Howells */ 5558feae131SDavid Howells static void __put_nommu_region(struct vm_region *region) 5568feae131SDavid Howells __releases(nommu_region_sem) 5578feae131SDavid Howells { 5588feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5598feae131SDavid Howells 5601e2ae599SDavid Howells if (--region->vm_usage == 0) { 561dd8632a1SPaul Mundt if (region->vm_top > region->vm_start) 5628feae131SDavid Howells delete_nommu_region(region); 5638feae131SDavid Howells up_write(&nommu_region_sem); 5648feae131SDavid Howells 5658feae131SDavid Howells if (region->vm_file) 5668feae131SDavid Howells fput(region->vm_file); 5678feae131SDavid Howells 5688feae131SDavid Howells /* IO memory and memory shared directly out of the pagecache 5698feae131SDavid Howells * from ramfs/tmpfs mustn't be released here */ 57022cc877bSLeon Romanovsky if (region->vm_flags & VM_MAPPED_COPY) 571dd8632a1SPaul Mundt free_page_series(region->vm_start, region->vm_top); 5728feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 5738feae131SDavid Howells } else { 5748feae131SDavid Howells up_write(&nommu_region_sem); 5758feae131SDavid Howells } 5768feae131SDavid Howells } 5778feae131SDavid Howells 5788feae131SDavid Howells /* 5798feae131SDavid Howells * release a reference to a region 5808feae131SDavid Howells */ 5818feae131SDavid Howells static void put_nommu_region(struct vm_region *region) 5828feae131SDavid Howells { 5838feae131SDavid Howells down_write(&nommu_region_sem); 5848feae131SDavid Howells __put_nommu_region(region); 5858feae131SDavid Howells } 5861da177e4SLinus Torvalds 5873034097aSDavid Howells /* 5883034097aSDavid Howells * add a VMA into a process's mm_struct in the appropriate place in the list 5898feae131SDavid Howells * and tree and add to the address space's page tree also if not an anonymous 5908feae131SDavid Howells * page 5913034097aSDavid Howells * - should be called with mm->mmap_sem held writelocked 5923034097aSDavid Howells */ 5938feae131SDavid Howells static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) 5943034097aSDavid Howells { 5956038def0SNamhyung Kim struct vm_area_struct *pvma, *prev; 5968feae131SDavid Howells struct address_space *mapping; 5976038def0SNamhyung Kim struct rb_node **p, *parent, *rb_prev; 5983034097aSDavid Howells 5998feae131SDavid Howells BUG_ON(!vma->vm_region); 6008feae131SDavid Howells 6018feae131SDavid Howells mm->map_count++; 6028feae131SDavid Howells vma->vm_mm = mm; 6038feae131SDavid Howells 6048feae131SDavid Howells /* add the VMA to the mapping */ 6058feae131SDavid Howells if (vma->vm_file) { 6068feae131SDavid Howells mapping = vma->vm_file->f_mapping; 6078feae131SDavid Howells 60883cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 6098feae131SDavid Howells flush_dcache_mmap_lock(mapping); 6106b2dbba8SMichel Lespinasse vma_interval_tree_insert(vma, &mapping->i_mmap); 6118feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 61283cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 6138feae131SDavid Howells } 6148feae131SDavid Howells 6158feae131SDavid Howells /* add the VMA to the tree */ 6166038def0SNamhyung Kim parent = rb_prev = NULL; 6178feae131SDavid Howells p = &mm->mm_rb.rb_node; 6188feae131SDavid Howells while (*p) { 6198feae131SDavid Howells parent = *p; 6208feae131SDavid Howells pvma = rb_entry(parent, struct vm_area_struct, vm_rb); 6218feae131SDavid Howells 6228feae131SDavid Howells /* sort by: start addr, end addr, VMA struct addr in that order 6238feae131SDavid Howells * (the latter is necessary as we may get identical VMAs) */ 6248feae131SDavid Howells if (vma->vm_start < pvma->vm_start) 6258feae131SDavid Howells p = &(*p)->rb_left; 6266038def0SNamhyung Kim else if (vma->vm_start > pvma->vm_start) { 6276038def0SNamhyung Kim rb_prev = parent; 6288feae131SDavid Howells p = &(*p)->rb_right; 6296038def0SNamhyung Kim } else if (vma->vm_end < pvma->vm_end) 6308feae131SDavid Howells p = &(*p)->rb_left; 6316038def0SNamhyung Kim else if (vma->vm_end > pvma->vm_end) { 6326038def0SNamhyung Kim rb_prev = parent; 6338feae131SDavid Howells p = &(*p)->rb_right; 6346038def0SNamhyung Kim } else if (vma < pvma) 6358feae131SDavid Howells p = &(*p)->rb_left; 6366038def0SNamhyung Kim else if (vma > pvma) { 6376038def0SNamhyung Kim rb_prev = parent; 6388feae131SDavid Howells p = &(*p)->rb_right; 6396038def0SNamhyung Kim } else 6408feae131SDavid Howells BUG(); 6418feae131SDavid Howells } 6428feae131SDavid Howells 6438feae131SDavid Howells rb_link_node(&vma->vm_rb, parent, p); 6448feae131SDavid Howells rb_insert_color(&vma->vm_rb, &mm->mm_rb); 6458feae131SDavid Howells 6468feae131SDavid Howells /* add VMA to the VMA list also */ 6476038def0SNamhyung Kim prev = NULL; 6486038def0SNamhyung Kim if (rb_prev) 6496038def0SNamhyung Kim prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); 6503034097aSDavid Howells 6516038def0SNamhyung Kim __vma_link_list(mm, vma, prev, parent); 6528feae131SDavid Howells } 6538feae131SDavid Howells 6548feae131SDavid Howells /* 6558feae131SDavid Howells * delete a VMA from its owning mm_struct and address space 6568feae131SDavid Howells */ 6578feae131SDavid Howells static void delete_vma_from_mm(struct vm_area_struct *vma) 6588feae131SDavid Howells { 659615d6e87SDavidlohr Bueso int i; 6608feae131SDavid Howells struct address_space *mapping; 6618feae131SDavid Howells struct mm_struct *mm = vma->vm_mm; 662615d6e87SDavidlohr Bueso struct task_struct *curr = current; 6638feae131SDavid Howells 6648feae131SDavid Howells mm->map_count--; 665615d6e87SDavidlohr Bueso for (i = 0; i < VMACACHE_SIZE; i++) { 666615d6e87SDavidlohr Bueso /* if the vma is cached, invalidate the entire cache */ 667314ff785SIngo Molnar if (curr->vmacache.vmas[i] == vma) { 668e020d5bdSSteven Miao vmacache_invalidate(mm); 669615d6e87SDavidlohr Bueso break; 670615d6e87SDavidlohr Bueso } 671615d6e87SDavidlohr Bueso } 6728feae131SDavid Howells 6738feae131SDavid Howells /* remove the VMA from the mapping */ 6748feae131SDavid Howells if (vma->vm_file) { 6758feae131SDavid Howells mapping = vma->vm_file->f_mapping; 6768feae131SDavid Howells 67783cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 6788feae131SDavid Howells flush_dcache_mmap_lock(mapping); 6796b2dbba8SMichel Lespinasse vma_interval_tree_remove(vma, &mapping->i_mmap); 6808feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 68183cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 6828feae131SDavid Howells } 6838feae131SDavid Howells 6848feae131SDavid Howells /* remove from the MM's tree and list */ 6858feae131SDavid Howells rb_erase(&vma->vm_rb, &mm->mm_rb); 686b951bf2cSNamhyung Kim 687b951bf2cSNamhyung Kim if (vma->vm_prev) 688b951bf2cSNamhyung Kim vma->vm_prev->vm_next = vma->vm_next; 689b951bf2cSNamhyung Kim else 690b951bf2cSNamhyung Kim mm->mmap = vma->vm_next; 691b951bf2cSNamhyung Kim 692b951bf2cSNamhyung Kim if (vma->vm_next) 693b951bf2cSNamhyung Kim vma->vm_next->vm_prev = vma->vm_prev; 6948feae131SDavid Howells } 6958feae131SDavid Howells 6968feae131SDavid Howells /* 6978feae131SDavid Howells * destroy a VMA record 6988feae131SDavid Howells */ 6998feae131SDavid Howells static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) 7008feae131SDavid Howells { 7018feae131SDavid Howells if (vma->vm_ops && vma->vm_ops->close) 7028feae131SDavid Howells vma->vm_ops->close(vma); 703e9714acfSKonstantin Khlebnikov if (vma->vm_file) 7048feae131SDavid Howells fput(vma->vm_file); 7058feae131SDavid Howells put_nommu_region(vma->vm_region); 7063928d4f5SLinus Torvalds vm_area_free(vma); 7073034097aSDavid Howells } 7083034097aSDavid Howells 7093034097aSDavid Howells /* 7103034097aSDavid Howells * look up the first VMA in which addr resides, NULL if none 7113034097aSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 7123034097aSDavid Howells */ 7133034097aSDavid Howells struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) 7143034097aSDavid Howells { 7158feae131SDavid Howells struct vm_area_struct *vma; 7163034097aSDavid Howells 7178feae131SDavid Howells /* check the cache first */ 718615d6e87SDavidlohr Bueso vma = vmacache_find(mm, addr); 719615d6e87SDavidlohr Bueso if (likely(vma)) 7208feae131SDavid Howells return vma; 7218feae131SDavid Howells 722e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 7238feae131SDavid Howells * resides) */ 724e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 7258feae131SDavid Howells if (vma->vm_start > addr) 7268feae131SDavid Howells return NULL; 7278feae131SDavid Howells if (vma->vm_end > addr) { 728615d6e87SDavidlohr Bueso vmacache_update(addr, vma); 7298feae131SDavid Howells return vma; 7303034097aSDavid Howells } 7318feae131SDavid Howells } 7323034097aSDavid Howells 7333034097aSDavid Howells return NULL; 7343034097aSDavid Howells } 7353034097aSDavid Howells EXPORT_SYMBOL(find_vma); 7363034097aSDavid Howells 7373034097aSDavid Howells /* 738930e652aSDavid Howells * find a VMA 739930e652aSDavid Howells * - we don't extend stack VMAs under NOMMU conditions 740930e652aSDavid Howells */ 741930e652aSDavid Howells struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) 742930e652aSDavid Howells { 7437561e8caSDavid Howells return find_vma(mm, addr); 744930e652aSDavid Howells } 745930e652aSDavid Howells 7468feae131SDavid Howells /* 7478feae131SDavid Howells * expand a stack to a given address 7488feae131SDavid Howells * - not supported under NOMMU conditions 7498feae131SDavid Howells */ 75057c8f63eSGreg Ungerer int expand_stack(struct vm_area_struct *vma, unsigned long address) 75157c8f63eSGreg Ungerer { 75257c8f63eSGreg Ungerer return -ENOMEM; 75357c8f63eSGreg Ungerer } 75457c8f63eSGreg Ungerer 755930e652aSDavid Howells /* 7566fa5f80bSDavid Howells * look up the first VMA exactly that exactly matches addr 7576fa5f80bSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 7586fa5f80bSDavid Howells */ 7598feae131SDavid Howells static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, 7608feae131SDavid Howells unsigned long addr, 7618feae131SDavid Howells unsigned long len) 7621da177e4SLinus Torvalds { 7631da177e4SLinus Torvalds struct vm_area_struct *vma; 7648feae131SDavid Howells unsigned long end = addr + len; 7651da177e4SLinus Torvalds 7668feae131SDavid Howells /* check the cache first */ 767615d6e87SDavidlohr Bueso vma = vmacache_find_exact(mm, addr, end); 768615d6e87SDavidlohr Bueso if (vma) 7691da177e4SLinus Torvalds return vma; 7708feae131SDavid Howells 771e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 7728feae131SDavid Howells * resides) */ 773e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 7748feae131SDavid Howells if (vma->vm_start < addr) 7758feae131SDavid Howells continue; 7768feae131SDavid Howells if (vma->vm_start > addr) 7778feae131SDavid Howells return NULL; 7788feae131SDavid Howells if (vma->vm_end == end) { 779615d6e87SDavidlohr Bueso vmacache_update(addr, vma); 7808feae131SDavid Howells return vma; 7818feae131SDavid Howells } 7821da177e4SLinus Torvalds } 7831da177e4SLinus Torvalds 7841da177e4SLinus Torvalds return NULL; 7851da177e4SLinus Torvalds } 7861da177e4SLinus Torvalds 7873034097aSDavid Howells /* 7881da177e4SLinus Torvalds * determine whether a mapping should be permitted and, if so, what sort of 7891da177e4SLinus Torvalds * mapping we're capable of supporting 7901da177e4SLinus Torvalds */ 7911da177e4SLinus Torvalds static int validate_mmap_request(struct file *file, 7921da177e4SLinus Torvalds unsigned long addr, 7931da177e4SLinus Torvalds unsigned long len, 7941da177e4SLinus Torvalds unsigned long prot, 7951da177e4SLinus Torvalds unsigned long flags, 7961da177e4SLinus Torvalds unsigned long pgoff, 7971da177e4SLinus Torvalds unsigned long *_capabilities) 7981da177e4SLinus Torvalds { 7998feae131SDavid Howells unsigned long capabilities, rlen; 8001da177e4SLinus Torvalds int ret; 8011da177e4SLinus Torvalds 8021da177e4SLinus Torvalds /* do the simple checks first */ 80322cc877bSLeon Romanovsky if (flags & MAP_FIXED) 8041da177e4SLinus Torvalds return -EINVAL; 8051da177e4SLinus Torvalds 8061da177e4SLinus Torvalds if ((flags & MAP_TYPE) != MAP_PRIVATE && 8071da177e4SLinus Torvalds (flags & MAP_TYPE) != MAP_SHARED) 8081da177e4SLinus Torvalds return -EINVAL; 8091da177e4SLinus Torvalds 810f81cff0dSMike Frysinger if (!len) 8111da177e4SLinus Torvalds return -EINVAL; 8121da177e4SLinus Torvalds 813f81cff0dSMike Frysinger /* Careful about overflows.. */ 8148feae131SDavid Howells rlen = PAGE_ALIGN(len); 8158feae131SDavid Howells if (!rlen || rlen > TASK_SIZE) 816f81cff0dSMike Frysinger return -ENOMEM; 817f81cff0dSMike Frysinger 8181da177e4SLinus Torvalds /* offset overflow? */ 8198feae131SDavid Howells if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) 820f81cff0dSMike Frysinger return -EOVERFLOW; 8211da177e4SLinus Torvalds 8221da177e4SLinus Torvalds if (file) { 8231da177e4SLinus Torvalds /* files must support mmap */ 82472c2d531SAl Viro if (!file->f_op->mmap) 8251da177e4SLinus Torvalds return -ENODEV; 8261da177e4SLinus Torvalds 8271da177e4SLinus Torvalds /* work out if what we've got could possibly be shared 8281da177e4SLinus Torvalds * - we support chardevs that provide their own "memory" 8291da177e4SLinus Torvalds * - we support files/blockdevs that are memory backed 8301da177e4SLinus Torvalds */ 831b4caecd4SChristoph Hellwig if (file->f_op->mmap_capabilities) { 832b4caecd4SChristoph Hellwig capabilities = file->f_op->mmap_capabilities(file); 833b4caecd4SChristoph Hellwig } else { 8341da177e4SLinus Torvalds /* no explicit capabilities set, so assume some 8351da177e4SLinus Torvalds * defaults */ 836496ad9aaSAl Viro switch (file_inode(file)->i_mode & S_IFMT) { 8371da177e4SLinus Torvalds case S_IFREG: 8381da177e4SLinus Torvalds case S_IFBLK: 839b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 8401da177e4SLinus Torvalds break; 8411da177e4SLinus Torvalds 8421da177e4SLinus Torvalds case S_IFCHR: 8431da177e4SLinus Torvalds capabilities = 844b4caecd4SChristoph Hellwig NOMMU_MAP_DIRECT | 845b4caecd4SChristoph Hellwig NOMMU_MAP_READ | 846b4caecd4SChristoph Hellwig NOMMU_MAP_WRITE; 8471da177e4SLinus Torvalds break; 8481da177e4SLinus Torvalds 8491da177e4SLinus Torvalds default: 8501da177e4SLinus Torvalds return -EINVAL; 8511da177e4SLinus Torvalds } 8521da177e4SLinus Torvalds } 8531da177e4SLinus Torvalds 8541da177e4SLinus Torvalds /* eliminate any capabilities that we can't support on this 8551da177e4SLinus Torvalds * device */ 8561da177e4SLinus Torvalds if (!file->f_op->get_unmapped_area) 857b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8586e242a1cSAl Viro if (!(file->f_mode & FMODE_CAN_READ)) 859b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 8601da177e4SLinus Torvalds 86128d7a6aeSGraff Yang /* The file shall have been opened with read permission. */ 86228d7a6aeSGraff Yang if (!(file->f_mode & FMODE_READ)) 86328d7a6aeSGraff Yang return -EACCES; 86428d7a6aeSGraff Yang 8651da177e4SLinus Torvalds if (flags & MAP_SHARED) { 8661da177e4SLinus Torvalds /* do checks for writing, appending and locking */ 8671da177e4SLinus Torvalds if ((prot & PROT_WRITE) && 8681da177e4SLinus Torvalds !(file->f_mode & FMODE_WRITE)) 8691da177e4SLinus Torvalds return -EACCES; 8701da177e4SLinus Torvalds 871496ad9aaSAl Viro if (IS_APPEND(file_inode(file)) && 8721da177e4SLinus Torvalds (file->f_mode & FMODE_WRITE)) 8731da177e4SLinus Torvalds return -EACCES; 8741da177e4SLinus Torvalds 875d7a06983SJeff Layton if (locks_verify_locked(file)) 8761da177e4SLinus Torvalds return -EAGAIN; 8771da177e4SLinus Torvalds 878b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 8791da177e4SLinus Torvalds return -ENODEV; 8801da177e4SLinus Torvalds 8811da177e4SLinus Torvalds /* we mustn't privatise shared mappings */ 882b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 883ac714904SChoi Gi-yong } else { 8841da177e4SLinus Torvalds /* we're going to read the file into private memory we 8851da177e4SLinus Torvalds * allocate */ 886b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 8871da177e4SLinus Torvalds return -ENODEV; 8881da177e4SLinus Torvalds 8891da177e4SLinus Torvalds /* we don't permit a private writable mapping to be 8901da177e4SLinus Torvalds * shared with the backing device */ 8911da177e4SLinus Torvalds if (prot & PROT_WRITE) 892b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8931da177e4SLinus Torvalds } 8941da177e4SLinus Torvalds 895b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 896b4caecd4SChristoph Hellwig if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) || 897b4caecd4SChristoph Hellwig ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) || 898b4caecd4SChristoph Hellwig ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC)) 8993c7b2045SBernd Schmidt ) { 900b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 9013c7b2045SBernd Schmidt if (flags & MAP_SHARED) { 90222cc877bSLeon Romanovsky pr_warn("MAP_SHARED not completely supported on !MMU\n"); 9033c7b2045SBernd Schmidt return -EINVAL; 9043c7b2045SBernd Schmidt } 9053c7b2045SBernd Schmidt } 9063c7b2045SBernd Schmidt } 9073c7b2045SBernd Schmidt 9081da177e4SLinus Torvalds /* handle executable mappings and implied executable 9091da177e4SLinus Torvalds * mappings */ 91090f8572bSEric W. Biederman if (path_noexec(&file->f_path)) { 9111da177e4SLinus Torvalds if (prot & PROT_EXEC) 9121da177e4SLinus Torvalds return -EPERM; 913ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { 9141da177e4SLinus Torvalds /* handle implication of PROT_EXEC by PROT_READ */ 9151da177e4SLinus Torvalds if (current->personality & READ_IMPLIES_EXEC) { 916b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_EXEC) 9171da177e4SLinus Torvalds prot |= PROT_EXEC; 9181da177e4SLinus Torvalds } 919ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && 9201da177e4SLinus Torvalds (prot & PROT_EXEC) && 921b4caecd4SChristoph Hellwig !(capabilities & NOMMU_MAP_EXEC) 9221da177e4SLinus Torvalds ) { 9231da177e4SLinus Torvalds /* backing file is not executable, try to copy */ 924b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 9251da177e4SLinus Torvalds } 926ac714904SChoi Gi-yong } else { 9271da177e4SLinus Torvalds /* anonymous mappings are always memory backed and can be 9281da177e4SLinus Torvalds * privately mapped 9291da177e4SLinus Torvalds */ 930b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 9311da177e4SLinus Torvalds 9321da177e4SLinus Torvalds /* handle PROT_EXEC implication by PROT_READ */ 9331da177e4SLinus Torvalds if ((prot & PROT_READ) && 9341da177e4SLinus Torvalds (current->personality & READ_IMPLIES_EXEC)) 9351da177e4SLinus Torvalds prot |= PROT_EXEC; 9361da177e4SLinus Torvalds } 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds /* allow the security API to have its say */ 939e5467859SAl Viro ret = security_mmap_addr(addr); 940e5467859SAl Viro if (ret < 0) 941e5467859SAl Viro return ret; 9421da177e4SLinus Torvalds 9431da177e4SLinus Torvalds /* looks okay */ 9441da177e4SLinus Torvalds *_capabilities = capabilities; 9451da177e4SLinus Torvalds return 0; 9461da177e4SLinus Torvalds } 9471da177e4SLinus Torvalds 9481da177e4SLinus Torvalds /* 9491da177e4SLinus Torvalds * we've determined that we can make the mapping, now translate what we 9501da177e4SLinus Torvalds * now know into VMA flags 9511da177e4SLinus Torvalds */ 9521da177e4SLinus Torvalds static unsigned long determine_vm_flags(struct file *file, 9531da177e4SLinus Torvalds unsigned long prot, 9541da177e4SLinus Torvalds unsigned long flags, 9551da177e4SLinus Torvalds unsigned long capabilities) 9561da177e4SLinus Torvalds { 9571da177e4SLinus Torvalds unsigned long vm_flags; 9581da177e4SLinus Torvalds 959e6bfb709SDave Hansen vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags); 9601da177e4SLinus Torvalds /* vm_flags |= mm->def_flags; */ 9611da177e4SLinus Torvalds 962b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) { 9631da177e4SLinus Torvalds /* attempt to share read-only copies of mapped file chunks */ 9643c7b2045SBernd Schmidt vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; 9651da177e4SLinus Torvalds if (file && !(prot & PROT_WRITE)) 9661da177e4SLinus Torvalds vm_flags |= VM_MAYSHARE; 9673c7b2045SBernd Schmidt } else { 9681da177e4SLinus Torvalds /* overlay a shareable mapping on the backing device or inode 9691da177e4SLinus Torvalds * if possible - used for chardevs, ramfs/tmpfs/shmfs and 9701da177e4SLinus Torvalds * romfs/cramfs */ 971b4caecd4SChristoph Hellwig vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS); 9721da177e4SLinus Torvalds if (flags & MAP_SHARED) 9733c7b2045SBernd Schmidt vm_flags |= VM_SHARED; 9741da177e4SLinus Torvalds } 9751da177e4SLinus Torvalds 9761da177e4SLinus Torvalds /* refuse to let anyone share private mappings with this process if 9771da177e4SLinus Torvalds * it's being traced - otherwise breakpoints set in it may interfere 9781da177e4SLinus Torvalds * with another untraced process 9791da177e4SLinus Torvalds */ 980a288eeccSTejun Heo if ((flags & MAP_PRIVATE) && current->ptrace) 9811da177e4SLinus Torvalds vm_flags &= ~VM_MAYSHARE; 9821da177e4SLinus Torvalds 9831da177e4SLinus Torvalds return vm_flags; 9841da177e4SLinus Torvalds } 9851da177e4SLinus Torvalds 9861da177e4SLinus Torvalds /* 9878feae131SDavid Howells * set up a shared mapping on a file (the driver or filesystem provides and 9888feae131SDavid Howells * pins the storage) 9891da177e4SLinus Torvalds */ 9908feae131SDavid Howells static int do_mmap_shared_file(struct vm_area_struct *vma) 9911da177e4SLinus Torvalds { 9921da177e4SLinus Torvalds int ret; 9931da177e4SLinus Torvalds 994f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 995dd8632a1SPaul Mundt if (ret == 0) { 996dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 997645d83c5SDavid Howells return 0; 998dd8632a1SPaul Mundt } 9991da177e4SLinus Torvalds if (ret != -ENOSYS) 10001da177e4SLinus Torvalds return ret; 10011da177e4SLinus Torvalds 10023fa30460SDavid Howells /* getting -ENOSYS indicates that direct mmap isn't possible (as 10033fa30460SDavid Howells * opposed to tried but failed) so we can only give a suitable error as 10043fa30460SDavid Howells * it's not possible to make a private copy if MAP_SHARED was given */ 10051da177e4SLinus Torvalds return -ENODEV; 10061da177e4SLinus Torvalds } 10071da177e4SLinus Torvalds 10081da177e4SLinus Torvalds /* 10091da177e4SLinus Torvalds * set up a private mapping or an anonymous shared mapping 10101da177e4SLinus Torvalds */ 10118feae131SDavid Howells static int do_mmap_private(struct vm_area_struct *vma, 10128feae131SDavid Howells struct vm_region *region, 1013645d83c5SDavid Howells unsigned long len, 1014645d83c5SDavid Howells unsigned long capabilities) 10151da177e4SLinus Torvalds { 1016dbc8358cSJoonsoo Kim unsigned long total, point; 10171da177e4SLinus Torvalds void *base; 10188feae131SDavid Howells int ret, order; 10191da177e4SLinus Torvalds 10201da177e4SLinus Torvalds /* invoke the file's mapping function so that it can keep track of 10211da177e4SLinus Torvalds * shared mappings on devices or memory 10221da177e4SLinus Torvalds * - VM_MAYSHARE will be set if it may attempt to share 10231da177e4SLinus Torvalds */ 1024b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 1025f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 1026dd8632a1SPaul Mundt if (ret == 0) { 10271da177e4SLinus Torvalds /* shouldn't return success if we're not sharing */ 1028dd8632a1SPaul Mundt BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); 1029dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 1030645d83c5SDavid Howells return 0; 10311da177e4SLinus Torvalds } 1032dd8632a1SPaul Mundt if (ret != -ENOSYS) 1033dd8632a1SPaul Mundt return ret; 10341da177e4SLinus Torvalds 10351da177e4SLinus Torvalds /* getting an ENOSYS error indicates that direct mmap isn't 10361da177e4SLinus Torvalds * possible (as opposed to tried but failed) so we'll try to 10371da177e4SLinus Torvalds * make a private copy of the data and map that instead */ 10381da177e4SLinus Torvalds } 10391da177e4SLinus Torvalds 10408feae131SDavid Howells 10411da177e4SLinus Torvalds /* allocate some memory to hold the mapping 10421da177e4SLinus Torvalds * - note that this may not return a page-aligned address if the object 10431da177e4SLinus Torvalds * we're allocating is smaller than a page 10441da177e4SLinus Torvalds */ 1045f67d9b15SBob Liu order = get_order(len); 10468feae131SDavid Howells total = 1 << order; 1047f67d9b15SBob Liu point = len >> PAGE_SHIFT; 1048dd8632a1SPaul Mundt 1049dbc8358cSJoonsoo Kim /* we don't want to allocate a power-of-2 sized page set */ 105022cc877bSLeon Romanovsky if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) 1051dbc8358cSJoonsoo Kim total = point; 10528feae131SDavid Howells 1053da616534SJoonsoo Kim base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL); 1054dbc8358cSJoonsoo Kim if (!base) 1055dbc8358cSJoonsoo Kim goto enomem; 10568feae131SDavid Howells 1057dbc8358cSJoonsoo Kim atomic_long_add(total, &mmap_pages_allocated); 1058dbc8358cSJoonsoo Kim 10598feae131SDavid Howells region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; 10608feae131SDavid Howells region->vm_start = (unsigned long) base; 1061f67d9b15SBob Liu region->vm_end = region->vm_start + len; 1062dd8632a1SPaul Mundt region->vm_top = region->vm_start + (total << PAGE_SHIFT); 10638feae131SDavid Howells 10648feae131SDavid Howells vma->vm_start = region->vm_start; 10658feae131SDavid Howells vma->vm_end = region->vm_start + len; 10661da177e4SLinus Torvalds 10671da177e4SLinus Torvalds if (vma->vm_file) { 10681da177e4SLinus Torvalds /* read the contents of a file into the copy */ 10691da177e4SLinus Torvalds loff_t fpos; 10701da177e4SLinus Torvalds 10711da177e4SLinus Torvalds fpos = vma->vm_pgoff; 10721da177e4SLinus Torvalds fpos <<= PAGE_SHIFT; 10731da177e4SLinus Torvalds 1074b4bf802aSChristoph Hellwig ret = kernel_read(vma->vm_file, base, len, &fpos); 10751da177e4SLinus Torvalds if (ret < 0) 10761da177e4SLinus Torvalds goto error_free; 10771da177e4SLinus Torvalds 10781da177e4SLinus Torvalds /* clear the last little bit */ 1079f67d9b15SBob Liu if (ret < len) 1080f67d9b15SBob Liu memset(base + ret, 0, len - ret); 10811da177e4SLinus Torvalds 1082bfd40eafSKirill A. Shutemov } else { 1083bfd40eafSKirill A. Shutemov vma_set_anonymous(vma); 10841da177e4SLinus Torvalds } 10851da177e4SLinus Torvalds 10861da177e4SLinus Torvalds return 0; 10871da177e4SLinus Torvalds 10881da177e4SLinus Torvalds error_free: 10897223bb4aSNamhyung Kim free_page_series(region->vm_start, region->vm_top); 10908feae131SDavid Howells region->vm_start = vma->vm_start = 0; 10918feae131SDavid Howells region->vm_end = vma->vm_end = 0; 1092dd8632a1SPaul Mundt region->vm_top = 0; 10931da177e4SLinus Torvalds return ret; 10941da177e4SLinus Torvalds 10951da177e4SLinus Torvalds enomem: 1096b1de0d13SMitchel Humpherys pr_err("Allocation of length %lu from process %d (%s) failed\n", 109705ae6fa3SGreg Ungerer len, current->pid, current->comm); 10989af744d7SMichal Hocko show_free_areas(0, NULL); 10991da177e4SLinus Torvalds return -ENOMEM; 11001da177e4SLinus Torvalds } 11011da177e4SLinus Torvalds 11021da177e4SLinus Torvalds /* 11031da177e4SLinus Torvalds * handle mapping creation for uClinux 11041da177e4SLinus Torvalds */ 11051fcfd8dbSOleg Nesterov unsigned long do_mmap(struct file *file, 11061da177e4SLinus Torvalds unsigned long addr, 11071da177e4SLinus Torvalds unsigned long len, 11081da177e4SLinus Torvalds unsigned long prot, 11091da177e4SLinus Torvalds unsigned long flags, 11101fcfd8dbSOleg Nesterov vm_flags_t vm_flags, 1111bebeb3d6SMichel Lespinasse unsigned long pgoff, 1112897ab3e0SMike Rapoport unsigned long *populate, 1113897ab3e0SMike Rapoport struct list_head *uf) 11141da177e4SLinus Torvalds { 11158feae131SDavid Howells struct vm_area_struct *vma; 11168feae131SDavid Howells struct vm_region *region; 11171da177e4SLinus Torvalds struct rb_node *rb; 11181fcfd8dbSOleg Nesterov unsigned long capabilities, result; 11191da177e4SLinus Torvalds int ret; 11201da177e4SLinus Torvalds 112141badc15SMichel Lespinasse *populate = 0; 1122bebeb3d6SMichel Lespinasse 11231da177e4SLinus Torvalds /* decide whether we should attempt the mapping, and if so what sort of 11241da177e4SLinus Torvalds * mapping */ 11251da177e4SLinus Torvalds ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, 11261da177e4SLinus Torvalds &capabilities); 112722cc877bSLeon Romanovsky if (ret < 0) 11281da177e4SLinus Torvalds return ret; 11291da177e4SLinus Torvalds 113006aab5a3SDavid Howells /* we ignore the address hint */ 113106aab5a3SDavid Howells addr = 0; 1132f67d9b15SBob Liu len = PAGE_ALIGN(len); 113306aab5a3SDavid Howells 11341da177e4SLinus Torvalds /* we've determined that we can make the mapping, now translate what we 11351da177e4SLinus Torvalds * now know into VMA flags */ 11361fcfd8dbSOleg Nesterov vm_flags |= determine_vm_flags(file, prot, flags, capabilities); 11371da177e4SLinus Torvalds 11388feae131SDavid Howells /* we're going to need to record the mapping */ 11398feae131SDavid Howells region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); 11408feae131SDavid Howells if (!region) 11418feae131SDavid Howells goto error_getting_region; 11421da177e4SLinus Torvalds 1143490fc053SLinus Torvalds vma = vm_area_alloc(current->mm); 11448feae131SDavid Howells if (!vma) 11458feae131SDavid Howells goto error_getting_vma; 11461da177e4SLinus Torvalds 11471e2ae599SDavid Howells region->vm_usage = 1; 11488feae131SDavid Howells region->vm_flags = vm_flags; 11498feae131SDavid Howells region->vm_pgoff = pgoff; 11508feae131SDavid Howells 11518feae131SDavid Howells vma->vm_flags = vm_flags; 11528feae131SDavid Howells vma->vm_pgoff = pgoff; 11538feae131SDavid Howells 11548feae131SDavid Howells if (file) { 1155cb0942b8SAl Viro region->vm_file = get_file(file); 1156cb0942b8SAl Viro vma->vm_file = get_file(file); 11578feae131SDavid Howells } 11588feae131SDavid Howells 11598feae131SDavid Howells down_write(&nommu_region_sem); 11608feae131SDavid Howells 11618feae131SDavid Howells /* if we want to share, we need to check for regions created by other 11621da177e4SLinus Torvalds * mmap() calls that overlap with our proposed mapping 11638feae131SDavid Howells * - we can only share with a superset match on most regular files 11641da177e4SLinus Torvalds * - shared mappings on character devices and memory backed files are 11651da177e4SLinus Torvalds * permitted to overlap inexactly as far as we are concerned for in 11661da177e4SLinus Torvalds * these cases, sharing is handled in the driver or filesystem rather 11671da177e4SLinus Torvalds * than here 11681da177e4SLinus Torvalds */ 11691da177e4SLinus Torvalds if (vm_flags & VM_MAYSHARE) { 11708feae131SDavid Howells struct vm_region *pregion; 11718feae131SDavid Howells unsigned long pglen, rpglen, pgend, rpgend, start; 11721da177e4SLinus Torvalds 11738feae131SDavid Howells pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 11748feae131SDavid Howells pgend = pgoff + pglen; 1175165b2392SDavid Howells 11768feae131SDavid Howells for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { 11778feae131SDavid Howells pregion = rb_entry(rb, struct vm_region, vm_rb); 11781da177e4SLinus Torvalds 11798feae131SDavid Howells if (!(pregion->vm_flags & VM_MAYSHARE)) 11801da177e4SLinus Torvalds continue; 11811da177e4SLinus Torvalds 11821da177e4SLinus Torvalds /* search for overlapping mappings on the same file */ 1183496ad9aaSAl Viro if (file_inode(pregion->vm_file) != 1184496ad9aaSAl Viro file_inode(file)) 11851da177e4SLinus Torvalds continue; 11861da177e4SLinus Torvalds 11878feae131SDavid Howells if (pregion->vm_pgoff >= pgend) 11881da177e4SLinus Torvalds continue; 11891da177e4SLinus Torvalds 11908feae131SDavid Howells rpglen = pregion->vm_end - pregion->vm_start; 11918feae131SDavid Howells rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; 11928feae131SDavid Howells rpgend = pregion->vm_pgoff + rpglen; 11938feae131SDavid Howells if (pgoff >= rpgend) 11941da177e4SLinus Torvalds continue; 11951da177e4SLinus Torvalds 11968feae131SDavid Howells /* handle inexactly overlapping matches between 11978feae131SDavid Howells * mappings */ 11988feae131SDavid Howells if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && 11998feae131SDavid Howells !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { 12008feae131SDavid Howells /* new mapping is not a subset of the region */ 1201b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 12021da177e4SLinus Torvalds goto sharing_violation; 12031da177e4SLinus Torvalds continue; 12041da177e4SLinus Torvalds } 12051da177e4SLinus Torvalds 12068feae131SDavid Howells /* we've found a region we can share */ 12071e2ae599SDavid Howells pregion->vm_usage++; 12088feae131SDavid Howells vma->vm_region = pregion; 12098feae131SDavid Howells start = pregion->vm_start; 12108feae131SDavid Howells start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; 12118feae131SDavid Howells vma->vm_start = start; 12128feae131SDavid Howells vma->vm_end = start + len; 12131da177e4SLinus Torvalds 121422cc877bSLeon Romanovsky if (pregion->vm_flags & VM_MAPPED_COPY) 12158feae131SDavid Howells vma->vm_flags |= VM_MAPPED_COPY; 121622cc877bSLeon Romanovsky else { 12178feae131SDavid Howells ret = do_mmap_shared_file(vma); 12188feae131SDavid Howells if (ret < 0) { 12198feae131SDavid Howells vma->vm_region = NULL; 12208feae131SDavid Howells vma->vm_start = 0; 12218feae131SDavid Howells vma->vm_end = 0; 12221e2ae599SDavid Howells pregion->vm_usage--; 12238feae131SDavid Howells pregion = NULL; 12248feae131SDavid Howells goto error_just_free; 12251da177e4SLinus Torvalds } 12268feae131SDavid Howells } 12278feae131SDavid Howells fput(region->vm_file); 12288feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 12298feae131SDavid Howells region = pregion; 12308feae131SDavid Howells result = start; 12318feae131SDavid Howells goto share; 12328feae131SDavid Howells } 12331da177e4SLinus Torvalds 12341da177e4SLinus Torvalds /* obtain the address at which to make a shared mapping 12351da177e4SLinus Torvalds * - this is the hook for quasi-memory character devices to 12361da177e4SLinus Torvalds * tell us the location of a shared mapping 12371da177e4SLinus Torvalds */ 1238b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 12391da177e4SLinus Torvalds addr = file->f_op->get_unmapped_area(file, addr, len, 12401da177e4SLinus Torvalds pgoff, flags); 1241bb005a59SNamhyung Kim if (IS_ERR_VALUE(addr)) { 12421da177e4SLinus Torvalds ret = addr; 1243bb005a59SNamhyung Kim if (ret != -ENOSYS) 12448feae131SDavid Howells goto error_just_free; 12451da177e4SLinus Torvalds 12461da177e4SLinus Torvalds /* the driver refused to tell us where to site 12471da177e4SLinus Torvalds * the mapping so we'll have to attempt to copy 12481da177e4SLinus Torvalds * it */ 1249bb005a59SNamhyung Kim ret = -ENODEV; 1250b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 12518feae131SDavid Howells goto error_just_free; 12521da177e4SLinus Torvalds 1253b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 12548feae131SDavid Howells } else { 12558feae131SDavid Howells vma->vm_start = region->vm_start = addr; 12568feae131SDavid Howells vma->vm_end = region->vm_end = addr + len; 12571da177e4SLinus Torvalds } 12581da177e4SLinus Torvalds } 12591da177e4SLinus Torvalds } 12601da177e4SLinus Torvalds 12618feae131SDavid Howells vma->vm_region = region; 12621da177e4SLinus Torvalds 1263645d83c5SDavid Howells /* set up the mapping 1264b4caecd4SChristoph Hellwig * - the region is filled in if NOMMU_MAP_DIRECT is still set 1265645d83c5SDavid Howells */ 12661da177e4SLinus Torvalds if (file && vma->vm_flags & VM_SHARED) 12678feae131SDavid Howells ret = do_mmap_shared_file(vma); 12681da177e4SLinus Torvalds else 1269645d83c5SDavid Howells ret = do_mmap_private(vma, region, len, capabilities); 12701da177e4SLinus Torvalds if (ret < 0) 1271645d83c5SDavid Howells goto error_just_free; 1272645d83c5SDavid Howells add_nommu_region(region); 12738feae131SDavid Howells 1274ea637639SJie Zhang /* clear anonymous mappings that don't ask for uninitialized data */ 12750bf5f949SChristoph Hellwig if (!vma->vm_file && 12760bf5f949SChristoph Hellwig (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) || 12770bf5f949SChristoph Hellwig !(flags & MAP_UNINITIALIZED))) 1278ea637639SJie Zhang memset((void *)region->vm_start, 0, 1279ea637639SJie Zhang region->vm_end - region->vm_start); 1280ea637639SJie Zhang 12811da177e4SLinus Torvalds /* okay... we have a mapping; now we have to register it */ 12828feae131SDavid Howells result = vma->vm_start; 12831da177e4SLinus Torvalds 12841da177e4SLinus Torvalds current->mm->total_vm += len >> PAGE_SHIFT; 12851da177e4SLinus Torvalds 12868feae131SDavid Howells share: 12878feae131SDavid Howells add_vma_to_mm(current->mm, vma); 12881da177e4SLinus Torvalds 1289cfe79c00SMike Frysinger /* we flush the region from the icache only when the first executable 1290cfe79c00SMike Frysinger * mapping of it is made */ 1291cfe79c00SMike Frysinger if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { 1292cfe79c00SMike Frysinger flush_icache_range(region->vm_start, region->vm_end); 1293cfe79c00SMike Frysinger region->vm_icache_flushed = true; 1294cfe79c00SMike Frysinger } 12951da177e4SLinus Torvalds 1296cfe79c00SMike Frysinger up_write(&nommu_region_sem); 12971da177e4SLinus Torvalds 12988feae131SDavid Howells return result; 12991da177e4SLinus Torvalds 13008feae131SDavid Howells error_just_free: 13018feae131SDavid Howells up_write(&nommu_region_sem); 13028feae131SDavid Howells error: 130389a86402SDavid Howells if (region->vm_file) 13048feae131SDavid Howells fput(region->vm_file); 13058feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 130689a86402SDavid Howells if (vma->vm_file) 13078feae131SDavid Howells fput(vma->vm_file); 13083928d4f5SLinus Torvalds vm_area_free(vma); 13091da177e4SLinus Torvalds return ret; 13101da177e4SLinus Torvalds 13111da177e4SLinus Torvalds sharing_violation: 13128feae131SDavid Howells up_write(&nommu_region_sem); 131322cc877bSLeon Romanovsky pr_warn("Attempt to share mismatched mappings\n"); 13148feae131SDavid Howells ret = -EINVAL; 13158feae131SDavid Howells goto error; 13161da177e4SLinus Torvalds 13171da177e4SLinus Torvalds error_getting_vma: 13188feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 131922cc877bSLeon Romanovsky pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n", 13201da177e4SLinus Torvalds len, current->pid); 13219af744d7SMichal Hocko show_free_areas(0, NULL); 13221da177e4SLinus Torvalds return -ENOMEM; 13231da177e4SLinus Torvalds 13248feae131SDavid Howells error_getting_region: 132522cc877bSLeon Romanovsky pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n", 13261da177e4SLinus Torvalds len, current->pid); 13279af744d7SMichal Hocko show_free_areas(0, NULL); 13281da177e4SLinus Torvalds return -ENOMEM; 13291da177e4SLinus Torvalds } 13306be5ceb0SLinus Torvalds 1331a90f590aSDominik Brodowski unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, 1332a90f590aSDominik Brodowski unsigned long prot, unsigned long flags, 1333a90f590aSDominik Brodowski unsigned long fd, unsigned long pgoff) 133466f0dc48SHugh Dickins { 133566f0dc48SHugh Dickins struct file *file = NULL; 133666f0dc48SHugh Dickins unsigned long retval = -EBADF; 133766f0dc48SHugh Dickins 1338120a795dSAl Viro audit_mmap_fd(fd, flags); 133966f0dc48SHugh Dickins if (!(flags & MAP_ANONYMOUS)) { 134066f0dc48SHugh Dickins file = fget(fd); 134166f0dc48SHugh Dickins if (!file) 134266f0dc48SHugh Dickins goto out; 134366f0dc48SHugh Dickins } 134466f0dc48SHugh Dickins 134566f0dc48SHugh Dickins flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); 134666f0dc48SHugh Dickins 1347ad1ed293SGreg Ungerer retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); 134866f0dc48SHugh Dickins 134966f0dc48SHugh Dickins if (file) 135066f0dc48SHugh Dickins fput(file); 135166f0dc48SHugh Dickins out: 135266f0dc48SHugh Dickins return retval; 135366f0dc48SHugh Dickins } 135466f0dc48SHugh Dickins 1355a90f590aSDominik Brodowski SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 1356a90f590aSDominik Brodowski unsigned long, prot, unsigned long, flags, 1357a90f590aSDominik Brodowski unsigned long, fd, unsigned long, pgoff) 1358a90f590aSDominik Brodowski { 1359a90f590aSDominik Brodowski return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); 1360a90f590aSDominik Brodowski } 1361a90f590aSDominik Brodowski 1362a4679373SChristoph Hellwig #ifdef __ARCH_WANT_SYS_OLD_MMAP 1363a4679373SChristoph Hellwig struct mmap_arg_struct { 1364a4679373SChristoph Hellwig unsigned long addr; 1365a4679373SChristoph Hellwig unsigned long len; 1366a4679373SChristoph Hellwig unsigned long prot; 1367a4679373SChristoph Hellwig unsigned long flags; 1368a4679373SChristoph Hellwig unsigned long fd; 1369a4679373SChristoph Hellwig unsigned long offset; 1370a4679373SChristoph Hellwig }; 1371a4679373SChristoph Hellwig 1372a4679373SChristoph Hellwig SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) 1373a4679373SChristoph Hellwig { 1374a4679373SChristoph Hellwig struct mmap_arg_struct a; 1375a4679373SChristoph Hellwig 1376a4679373SChristoph Hellwig if (copy_from_user(&a, arg, sizeof(a))) 1377a4679373SChristoph Hellwig return -EFAULT; 13781824cb75SAlexander Kuleshov if (offset_in_page(a.offset)) 1379a4679373SChristoph Hellwig return -EINVAL; 1380a4679373SChristoph Hellwig 1381a90f590aSDominik Brodowski return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, 1382a4679373SChristoph Hellwig a.offset >> PAGE_SHIFT); 1383a4679373SChristoph Hellwig } 1384a4679373SChristoph Hellwig #endif /* __ARCH_WANT_SYS_OLD_MMAP */ 1385a4679373SChristoph Hellwig 13861da177e4SLinus Torvalds /* 13878feae131SDavid Howells * split a vma into two pieces at address 'addr', a new vma is allocated either 13888feae131SDavid Howells * for the first part or the tail. 13891da177e4SLinus Torvalds */ 13908feae131SDavid Howells int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 13918feae131SDavid Howells unsigned long addr, int new_below) 13921da177e4SLinus Torvalds { 13938feae131SDavid Howells struct vm_area_struct *new; 13948feae131SDavid Howells struct vm_region *region; 13958feae131SDavid Howells unsigned long npages; 13961da177e4SLinus Torvalds 1397779c1023SDavid Howells /* we're only permitted to split anonymous regions (these should have 1398779c1023SDavid Howells * only a single usage on the region) */ 1399779c1023SDavid Howells if (vma->vm_file) 14008feae131SDavid Howells return -ENOMEM; 14011da177e4SLinus Torvalds 14028feae131SDavid Howells if (mm->map_count >= sysctl_max_map_count) 14038feae131SDavid Howells return -ENOMEM; 14041da177e4SLinus Torvalds 14058feae131SDavid Howells region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); 14068feae131SDavid Howells if (!region) 14078feae131SDavid Howells return -ENOMEM; 14088feae131SDavid Howells 14093928d4f5SLinus Torvalds new = vm_area_dup(vma); 14108feae131SDavid Howells if (!new) { 14118feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 14128feae131SDavid Howells return -ENOMEM; 14131da177e4SLinus Torvalds } 14141da177e4SLinus Torvalds 14158feae131SDavid Howells /* most fields are the same, copy all, and then fixup */ 14168feae131SDavid Howells *region = *vma->vm_region; 14178feae131SDavid Howells new->vm_region = region; 14188feae131SDavid Howells 14198feae131SDavid Howells npages = (addr - vma->vm_start) >> PAGE_SHIFT; 14208feae131SDavid Howells 14218feae131SDavid Howells if (new_below) { 1422dd8632a1SPaul Mundt region->vm_top = region->vm_end = new->vm_end = addr; 14238feae131SDavid Howells } else { 14248feae131SDavid Howells region->vm_start = new->vm_start = addr; 14258feae131SDavid Howells region->vm_pgoff = new->vm_pgoff += npages; 14261da177e4SLinus Torvalds } 14278feae131SDavid Howells 14288feae131SDavid Howells if (new->vm_ops && new->vm_ops->open) 14298feae131SDavid Howells new->vm_ops->open(new); 14308feae131SDavid Howells 14318feae131SDavid Howells delete_vma_from_mm(vma); 14328feae131SDavid Howells down_write(&nommu_region_sem); 14338feae131SDavid Howells delete_nommu_region(vma->vm_region); 14348feae131SDavid Howells if (new_below) { 14358feae131SDavid Howells vma->vm_region->vm_start = vma->vm_start = addr; 14368feae131SDavid Howells vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; 14378feae131SDavid Howells } else { 14388feae131SDavid Howells vma->vm_region->vm_end = vma->vm_end = addr; 1439dd8632a1SPaul Mundt vma->vm_region->vm_top = addr; 14408feae131SDavid Howells } 14418feae131SDavid Howells add_nommu_region(vma->vm_region); 14428feae131SDavid Howells add_nommu_region(new->vm_region); 14438feae131SDavid Howells up_write(&nommu_region_sem); 14448feae131SDavid Howells add_vma_to_mm(mm, vma); 14458feae131SDavid Howells add_vma_to_mm(mm, new); 14468feae131SDavid Howells return 0; 14478feae131SDavid Howells } 14488feae131SDavid Howells 14498feae131SDavid Howells /* 14508feae131SDavid Howells * shrink a VMA by removing the specified chunk from either the beginning or 14518feae131SDavid Howells * the end 14528feae131SDavid Howells */ 14538feae131SDavid Howells static int shrink_vma(struct mm_struct *mm, 14548feae131SDavid Howells struct vm_area_struct *vma, 14558feae131SDavid Howells unsigned long from, unsigned long to) 14568feae131SDavid Howells { 14578feae131SDavid Howells struct vm_region *region; 14588feae131SDavid Howells 14598feae131SDavid Howells /* adjust the VMA's pointers, which may reposition it in the MM's tree 14608feae131SDavid Howells * and list */ 14618feae131SDavid Howells delete_vma_from_mm(vma); 14628feae131SDavid Howells if (from > vma->vm_start) 14638feae131SDavid Howells vma->vm_end = from; 14648feae131SDavid Howells else 14658feae131SDavid Howells vma->vm_start = to; 14668feae131SDavid Howells add_vma_to_mm(mm, vma); 14678feae131SDavid Howells 14688feae131SDavid Howells /* cut the backing region down to size */ 14698feae131SDavid Howells region = vma->vm_region; 14701e2ae599SDavid Howells BUG_ON(region->vm_usage != 1); 14718feae131SDavid Howells 14728feae131SDavid Howells down_write(&nommu_region_sem); 14738feae131SDavid Howells delete_nommu_region(region); 1474dd8632a1SPaul Mundt if (from > region->vm_start) { 1475dd8632a1SPaul Mundt to = region->vm_top; 1476dd8632a1SPaul Mundt region->vm_top = region->vm_end = from; 1477dd8632a1SPaul Mundt } else { 14788feae131SDavid Howells region->vm_start = to; 1479dd8632a1SPaul Mundt } 14808feae131SDavid Howells add_nommu_region(region); 14818feae131SDavid Howells up_write(&nommu_region_sem); 14828feae131SDavid Howells 14838feae131SDavid Howells free_page_series(from, to); 14848feae131SDavid Howells return 0; 14851da177e4SLinus Torvalds } 14861da177e4SLinus Torvalds 14873034097aSDavid Howells /* 14883034097aSDavid Howells * release a mapping 14898feae131SDavid Howells * - under NOMMU conditions the chunk to be unmapped must be backed by a single 14908feae131SDavid Howells * VMA, though it need not cover the whole VMA 14913034097aSDavid Howells */ 1492897ab3e0SMike Rapoport int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) 14931da177e4SLinus Torvalds { 14948feae131SDavid Howells struct vm_area_struct *vma; 1495f67d9b15SBob Liu unsigned long end; 14968feae131SDavid Howells int ret; 14971da177e4SLinus Torvalds 1498f67d9b15SBob Liu len = PAGE_ALIGN(len); 14998feae131SDavid Howells if (len == 0) 15001da177e4SLinus Torvalds return -EINVAL; 15011da177e4SLinus Torvalds 1502f67d9b15SBob Liu end = start + len; 1503f67d9b15SBob Liu 15048feae131SDavid Howells /* find the first potentially overlapping VMA */ 15058feae131SDavid Howells vma = find_vma(mm, start); 15068feae131SDavid Howells if (!vma) { 1507ac714904SChoi Gi-yong static int limit; 150833e5d769SDavid Howells if (limit < 5) { 150922cc877bSLeon Romanovsky pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n", 151033e5d769SDavid Howells current->pid, current->comm, 151133e5d769SDavid Howells start, start + len - 1); 151233e5d769SDavid Howells limit++; 151333e5d769SDavid Howells } 15148feae131SDavid Howells return -EINVAL; 15158feae131SDavid Howells } 15161da177e4SLinus Torvalds 15178feae131SDavid Howells /* we're allowed to split an anonymous VMA but not a file-backed one */ 15188feae131SDavid Howells if (vma->vm_file) { 15198feae131SDavid Howells do { 152022cc877bSLeon Romanovsky if (start > vma->vm_start) 15218feae131SDavid Howells return -EINVAL; 15228feae131SDavid Howells if (end == vma->vm_end) 15238feae131SDavid Howells goto erase_whole_vma; 1524d75a310cSNamhyung Kim vma = vma->vm_next; 1525d75a310cSNamhyung Kim } while (vma); 15268feae131SDavid Howells return -EINVAL; 15278feae131SDavid Howells } else { 15288feae131SDavid Howells /* the chunk must be a subset of the VMA found */ 15298feae131SDavid Howells if (start == vma->vm_start && end == vma->vm_end) 15308feae131SDavid Howells goto erase_whole_vma; 153122cc877bSLeon Romanovsky if (start < vma->vm_start || end > vma->vm_end) 15328feae131SDavid Howells return -EINVAL; 15331824cb75SAlexander Kuleshov if (offset_in_page(start)) 15348feae131SDavid Howells return -EINVAL; 15351824cb75SAlexander Kuleshov if (end != vma->vm_end && offset_in_page(end)) 15368feae131SDavid Howells return -EINVAL; 15378feae131SDavid Howells if (start != vma->vm_start && end != vma->vm_end) { 15388feae131SDavid Howells ret = split_vma(mm, vma, start, 1); 153922cc877bSLeon Romanovsky if (ret < 0) 15408feae131SDavid Howells return ret; 15418feae131SDavid Howells } 15428feae131SDavid Howells return shrink_vma(mm, vma, start, end); 15438feae131SDavid Howells } 15441da177e4SLinus Torvalds 15458feae131SDavid Howells erase_whole_vma: 15468feae131SDavid Howells delete_vma_from_mm(vma); 15478feae131SDavid Howells delete_vma(mm, vma); 15481da177e4SLinus Torvalds return 0; 15491da177e4SLinus Torvalds } 1550b5073173SPaul Mundt EXPORT_SYMBOL(do_munmap); 15511da177e4SLinus Torvalds 1552bfce281cSAl Viro int vm_munmap(unsigned long addr, size_t len) 15533034097aSDavid Howells { 1554bfce281cSAl Viro struct mm_struct *mm = current->mm; 15553034097aSDavid Howells int ret; 15563034097aSDavid Howells 15573034097aSDavid Howells down_write(&mm->mmap_sem); 1558897ab3e0SMike Rapoport ret = do_munmap(mm, addr, len, NULL); 15593034097aSDavid Howells up_write(&mm->mmap_sem); 15603034097aSDavid Howells return ret; 15613034097aSDavid Howells } 1562a46ef99dSLinus Torvalds EXPORT_SYMBOL(vm_munmap); 1563a46ef99dSLinus Torvalds 1564a46ef99dSLinus Torvalds SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) 1565a46ef99dSLinus Torvalds { 1566bfce281cSAl Viro return vm_munmap(addr, len); 1567a46ef99dSLinus Torvalds } 15683034097aSDavid Howells 15693034097aSDavid Howells /* 15708feae131SDavid Howells * release all the mappings made in a process's VM space 15713034097aSDavid Howells */ 15721da177e4SLinus Torvalds void exit_mmap(struct mm_struct *mm) 15731da177e4SLinus Torvalds { 15748feae131SDavid Howells struct vm_area_struct *vma; 15751da177e4SLinus Torvalds 15768feae131SDavid Howells if (!mm) 15778feae131SDavid Howells return; 15788feae131SDavid Howells 15791da177e4SLinus Torvalds mm->total_vm = 0; 15801da177e4SLinus Torvalds 15818feae131SDavid Howells while ((vma = mm->mmap)) { 15828feae131SDavid Howells mm->mmap = vma->vm_next; 15838feae131SDavid Howells delete_vma_from_mm(vma); 15848feae131SDavid Howells delete_vma(mm, vma); 158504c34961SSteven J. Magnani cond_resched(); 15861da177e4SLinus Torvalds } 15871da177e4SLinus Torvalds } 15881da177e4SLinus Torvalds 15895d22fc25SLinus Torvalds int vm_brk(unsigned long addr, unsigned long len) 15901da177e4SLinus Torvalds { 15911da177e4SLinus Torvalds return -ENOMEM; 15921da177e4SLinus Torvalds } 15931da177e4SLinus Torvalds 15941da177e4SLinus Torvalds /* 15956fa5f80bSDavid Howells * expand (or shrink) an existing mapping, potentially moving it at the same 15966fa5f80bSDavid Howells * time (controlled by the MREMAP_MAYMOVE flag and available VM space) 15971da177e4SLinus Torvalds * 15986fa5f80bSDavid Howells * under NOMMU conditions, we only permit changing a mapping's size, and only 15998feae131SDavid Howells * as long as it stays within the region allocated by do_mmap_private() and the 16008feae131SDavid Howells * block is not shareable 16011da177e4SLinus Torvalds * 16026fa5f80bSDavid Howells * MREMAP_FIXED is not supported under NOMMU conditions 16031da177e4SLinus Torvalds */ 16044b377babSAl Viro static unsigned long do_mremap(unsigned long addr, 16051da177e4SLinus Torvalds unsigned long old_len, unsigned long new_len, 16061da177e4SLinus Torvalds unsigned long flags, unsigned long new_addr) 16071da177e4SLinus Torvalds { 16086fa5f80bSDavid Howells struct vm_area_struct *vma; 16091da177e4SLinus Torvalds 16101da177e4SLinus Torvalds /* insanity checks first */ 1611f67d9b15SBob Liu old_len = PAGE_ALIGN(old_len); 1612f67d9b15SBob Liu new_len = PAGE_ALIGN(new_len); 16138feae131SDavid Howells if (old_len == 0 || new_len == 0) 16141da177e4SLinus Torvalds return (unsigned long) -EINVAL; 16151da177e4SLinus Torvalds 16161824cb75SAlexander Kuleshov if (offset_in_page(addr)) 16178feae131SDavid Howells return -EINVAL; 16188feae131SDavid Howells 16191da177e4SLinus Torvalds if (flags & MREMAP_FIXED && new_addr != addr) 16201da177e4SLinus Torvalds return (unsigned long) -EINVAL; 16211da177e4SLinus Torvalds 16228feae131SDavid Howells vma = find_vma_exact(current->mm, addr, old_len); 16236fa5f80bSDavid Howells if (!vma) 16241da177e4SLinus Torvalds return (unsigned long) -EINVAL; 16251da177e4SLinus Torvalds 16266fa5f80bSDavid Howells if (vma->vm_end != vma->vm_start + old_len) 16271da177e4SLinus Torvalds return (unsigned long) -EFAULT; 16281da177e4SLinus Torvalds 16296fa5f80bSDavid Howells if (vma->vm_flags & VM_MAYSHARE) 16301da177e4SLinus Torvalds return (unsigned long) -EPERM; 16311da177e4SLinus Torvalds 16328feae131SDavid Howells if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) 16331da177e4SLinus Torvalds return (unsigned long) -ENOMEM; 16341da177e4SLinus Torvalds 16351da177e4SLinus Torvalds /* all checks complete - do it */ 16366fa5f80bSDavid Howells vma->vm_end = vma->vm_start + new_len; 16376fa5f80bSDavid Howells return vma->vm_start; 16386fa5f80bSDavid Howells } 16396fa5f80bSDavid Howells 16406a6160a7SHeiko Carstens SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 16416a6160a7SHeiko Carstens unsigned long, new_len, unsigned long, flags, 16426a6160a7SHeiko Carstens unsigned long, new_addr) 16436fa5f80bSDavid Howells { 16446fa5f80bSDavid Howells unsigned long ret; 16456fa5f80bSDavid Howells 16466fa5f80bSDavid Howells down_write(¤t->mm->mmap_sem); 16476fa5f80bSDavid Howells ret = do_mremap(addr, old_len, new_len, flags, new_addr); 16486fa5f80bSDavid Howells up_write(¤t->mm->mmap_sem); 16496fa5f80bSDavid Howells return ret; 16501da177e4SLinus Torvalds } 16511da177e4SLinus Torvalds 1652df06b37fSKeith Busch struct page *follow_page(struct vm_area_struct *vma, unsigned long address, 1653df06b37fSKeith Busch unsigned int foll_flags) 16541da177e4SLinus Torvalds { 16551da177e4SLinus Torvalds return NULL; 16561da177e4SLinus Torvalds } 16571da177e4SLinus Torvalds 16588f3b1327SBob Liu int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 16598f3b1327SBob Liu unsigned long pfn, unsigned long size, pgprot_t prot) 16601da177e4SLinus Torvalds { 16618f3b1327SBob Liu if (addr != (pfn << PAGE_SHIFT)) 16628f3b1327SBob Liu return -EINVAL; 16638f3b1327SBob Liu 1664314e51b9SKonstantin Khlebnikov vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 166566aa2b4bSGreg Ungerer return 0; 16661da177e4SLinus Torvalds } 166722c4af40SLuke Yang EXPORT_SYMBOL(remap_pfn_range); 16681da177e4SLinus Torvalds 16693c0b9de6SLinus Torvalds int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) 16703c0b9de6SLinus Torvalds { 16713c0b9de6SLinus Torvalds unsigned long pfn = start >> PAGE_SHIFT; 16723c0b9de6SLinus Torvalds unsigned long vm_len = vma->vm_end - vma->vm_start; 16733c0b9de6SLinus Torvalds 16743c0b9de6SLinus Torvalds pfn += vma->vm_pgoff; 16753c0b9de6SLinus Torvalds return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); 16763c0b9de6SLinus Torvalds } 16773c0b9de6SLinus Torvalds EXPORT_SYMBOL(vm_iomap_memory); 16783c0b9de6SLinus Torvalds 1679f905bc44SPaul Mundt int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 1680f905bc44SPaul Mundt unsigned long pgoff) 1681f905bc44SPaul Mundt { 1682f905bc44SPaul Mundt unsigned int size = vma->vm_end - vma->vm_start; 1683f905bc44SPaul Mundt 1684f905bc44SPaul Mundt if (!(vma->vm_flags & VM_USERMAP)) 1685f905bc44SPaul Mundt return -EINVAL; 1686f905bc44SPaul Mundt 1687f905bc44SPaul Mundt vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); 1688f905bc44SPaul Mundt vma->vm_end = vma->vm_start + size; 1689f905bc44SPaul Mundt 1690f905bc44SPaul Mundt return 0; 1691f905bc44SPaul Mundt } 1692f905bc44SPaul Mundt EXPORT_SYMBOL(remap_vmalloc_range); 1693f905bc44SPaul Mundt 16941da177e4SLinus Torvalds unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, 16951da177e4SLinus Torvalds unsigned long len, unsigned long pgoff, unsigned long flags) 16961da177e4SLinus Torvalds { 16971da177e4SLinus Torvalds return -ENOMEM; 16981da177e4SLinus Torvalds } 16991da177e4SLinus Torvalds 17002bcd6454SSouptick Joarder vm_fault_t filemap_fault(struct vm_fault *vmf) 1701b0e15190SDavid Howells { 1702b0e15190SDavid Howells BUG(); 1703d0217ac0SNick Piggin return 0; 1704b0e15190SDavid Howells } 1705b5073173SPaul Mundt EXPORT_SYMBOL(filemap_fault); 17060ec76a11SDavid Howells 170782b0f8c3SJan Kara void filemap_map_pages(struct vm_fault *vmf, 1708bae473a4SKirill A. Shutemov pgoff_t start_pgoff, pgoff_t end_pgoff) 1709f1820361SKirill A. Shutemov { 1710f1820361SKirill A. Shutemov BUG(); 1711f1820361SKirill A. Shutemov } 1712f1820361SKirill A. Shutemov EXPORT_SYMBOL(filemap_map_pages); 1713f1820361SKirill A. Shutemov 171484d77d3fSEric W. Biederman int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, 1715442486ecSLorenzo Stoakes unsigned long addr, void *buf, int len, unsigned int gup_flags) 17160ec76a11SDavid Howells { 17170ec76a11SDavid Howells struct vm_area_struct *vma; 1718442486ecSLorenzo Stoakes int write = gup_flags & FOLL_WRITE; 17190ec76a11SDavid Howells 17201e426fe2SKonstantin Khlebnikov if (down_read_killable(&mm->mmap_sem)) 17211e426fe2SKonstantin Khlebnikov return 0; 17220ec76a11SDavid Howells 17230ec76a11SDavid Howells /* the access must start within one of the target process's mappings */ 17240159b141SDavid Howells vma = find_vma(mm, addr); 17250159b141SDavid Howells if (vma) { 17260ec76a11SDavid Howells /* don't overrun this mapping */ 17270ec76a11SDavid Howells if (addr + len >= vma->vm_end) 17280ec76a11SDavid Howells len = vma->vm_end - addr; 17290ec76a11SDavid Howells 17300ec76a11SDavid Howells /* only read or write mappings where it is permitted */ 1731d00c7b99SDavid Howells if (write && vma->vm_flags & VM_MAYWRITE) 17327959722bSJie Zhang copy_to_user_page(vma, NULL, addr, 17337959722bSJie Zhang (void *) addr, buf, len); 1734d00c7b99SDavid Howells else if (!write && vma->vm_flags & VM_MAYREAD) 17357959722bSJie Zhang copy_from_user_page(vma, NULL, addr, 17367959722bSJie Zhang buf, (void *) addr, len); 17370ec76a11SDavid Howells else 17380ec76a11SDavid Howells len = 0; 17390ec76a11SDavid Howells } else { 17400ec76a11SDavid Howells len = 0; 17410ec76a11SDavid Howells } 17420ec76a11SDavid Howells 17430ec76a11SDavid Howells up_read(&mm->mmap_sem); 1744f55f199bSMike Frysinger 1745f55f199bSMike Frysinger return len; 1746f55f199bSMike Frysinger } 1747f55f199bSMike Frysinger 1748f55f199bSMike Frysinger /** 1749b7701a5fSMike Rapoport * access_remote_vm - access another process' address space 1750f55f199bSMike Frysinger * @mm: the mm_struct of the target address space 1751f55f199bSMike Frysinger * @addr: start address to access 1752f55f199bSMike Frysinger * @buf: source or destination buffer 1753f55f199bSMike Frysinger * @len: number of bytes to transfer 17546347e8d5SLorenzo Stoakes * @gup_flags: flags modifying lookup behaviour 1755f55f199bSMike Frysinger * 1756f55f199bSMike Frysinger * The caller must hold a reference on @mm. 1757f55f199bSMike Frysinger */ 1758f55f199bSMike Frysinger int access_remote_vm(struct mm_struct *mm, unsigned long addr, 17596347e8d5SLorenzo Stoakes void *buf, int len, unsigned int gup_flags) 1760f55f199bSMike Frysinger { 17616347e8d5SLorenzo Stoakes return __access_remote_vm(NULL, mm, addr, buf, len, gup_flags); 1762f55f199bSMike Frysinger } 1763f55f199bSMike Frysinger 1764f55f199bSMike Frysinger /* 1765f55f199bSMike Frysinger * Access another process' address space. 1766f55f199bSMike Frysinger * - source/target buffer must be kernel space 1767f55f199bSMike Frysinger */ 1768f307ab6dSLorenzo Stoakes int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, 1769f307ab6dSLorenzo Stoakes unsigned int gup_flags) 1770f55f199bSMike Frysinger { 1771f55f199bSMike Frysinger struct mm_struct *mm; 1772f55f199bSMike Frysinger 1773f55f199bSMike Frysinger if (addr + len < addr) 1774f55f199bSMike Frysinger return 0; 1775f55f199bSMike Frysinger 1776f55f199bSMike Frysinger mm = get_task_mm(tsk); 1777f55f199bSMike Frysinger if (!mm) 1778f55f199bSMike Frysinger return 0; 1779f55f199bSMike Frysinger 1780f307ab6dSLorenzo Stoakes len = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags); 1781f55f199bSMike Frysinger 17820ec76a11SDavid Howells mmput(mm); 17830ec76a11SDavid Howells return len; 17840ec76a11SDavid Howells } 1785fcd35857SCatalin Marinas EXPORT_SYMBOL_GPL(access_process_vm); 17867e660872SDavid Howells 17877e660872SDavid Howells /** 17887e660872SDavid Howells * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode 17897e660872SDavid Howells * @inode: The inode to check 17907e660872SDavid Howells * @size: The current filesize of the inode 17917e660872SDavid Howells * @newsize: The proposed filesize of the inode 17927e660872SDavid Howells * 17937e660872SDavid Howells * Check the shared mappings on an inode on behalf of a shrinking truncate to 17947e660872SDavid Howells * make sure that that any outstanding VMAs aren't broken and then shrink the 17957e660872SDavid Howells * vm_regions that extend that beyond so that do_mmap_pgoff() doesn't 17967e660872SDavid Howells * automatically grant mappings that are too large. 17977e660872SDavid Howells */ 17987e660872SDavid Howells int nommu_shrink_inode_mappings(struct inode *inode, size_t size, 17997e660872SDavid Howells size_t newsize) 18007e660872SDavid Howells { 18017e660872SDavid Howells struct vm_area_struct *vma; 18027e660872SDavid Howells struct vm_region *region; 18037e660872SDavid Howells pgoff_t low, high; 18047e660872SDavid Howells size_t r_size, r_top; 18057e660872SDavid Howells 18067e660872SDavid Howells low = newsize >> PAGE_SHIFT; 18077e660872SDavid Howells high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 18087e660872SDavid Howells 18097e660872SDavid Howells down_write(&nommu_region_sem); 18101acf2e04SDavidlohr Bueso i_mmap_lock_read(inode->i_mapping); 18117e660872SDavid Howells 18127e660872SDavid Howells /* search for VMAs that fall within the dead zone */ 18136b2dbba8SMichel Lespinasse vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) { 18147e660872SDavid Howells /* found one - only interested if it's shared out of the page 18157e660872SDavid Howells * cache */ 18167e660872SDavid Howells if (vma->vm_flags & VM_SHARED) { 18171acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 18187e660872SDavid Howells up_write(&nommu_region_sem); 18197e660872SDavid Howells return -ETXTBSY; /* not quite true, but near enough */ 18207e660872SDavid Howells } 18217e660872SDavid Howells } 18227e660872SDavid Howells 18237e660872SDavid Howells /* reduce any regions that overlap the dead zone - if in existence, 18247e660872SDavid Howells * these will be pointed to by VMAs that don't overlap the dead zone 18257e660872SDavid Howells * 18267e660872SDavid Howells * we don't check for any regions that start beyond the EOF as there 18277e660872SDavid Howells * shouldn't be any 18287e660872SDavid Howells */ 18291acf2e04SDavidlohr Bueso vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 0, ULONG_MAX) { 18307e660872SDavid Howells if (!(vma->vm_flags & VM_SHARED)) 18317e660872SDavid Howells continue; 18327e660872SDavid Howells 18337e660872SDavid Howells region = vma->vm_region; 18347e660872SDavid Howells r_size = region->vm_top - region->vm_start; 18357e660872SDavid Howells r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; 18367e660872SDavid Howells 18377e660872SDavid Howells if (r_top > newsize) { 18387e660872SDavid Howells region->vm_top -= r_top - newsize; 18397e660872SDavid Howells if (region->vm_end > region->vm_top) 18407e660872SDavid Howells region->vm_end = region->vm_top; 18417e660872SDavid Howells } 18427e660872SDavid Howells } 18437e660872SDavid Howells 18441acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 18457e660872SDavid Howells up_write(&nommu_region_sem); 18467e660872SDavid Howells return 0; 18477e660872SDavid Howells } 1848c9b1d098SAndrew Shewmaker 1849c9b1d098SAndrew Shewmaker /* 1850c9b1d098SAndrew Shewmaker * Initialise sysctl_user_reserve_kbytes. 1851c9b1d098SAndrew Shewmaker * 1852c9b1d098SAndrew Shewmaker * This is intended to prevent a user from starting a single memory hogging 1853c9b1d098SAndrew Shewmaker * process, such that they cannot recover (kill the hog) in OVERCOMMIT_NEVER 1854c9b1d098SAndrew Shewmaker * mode. 1855c9b1d098SAndrew Shewmaker * 1856c9b1d098SAndrew Shewmaker * The default value is min(3% of free memory, 128MB) 1857c9b1d098SAndrew Shewmaker * 128MB is enough to recover with sshd/login, bash, and top/kill. 1858c9b1d098SAndrew Shewmaker */ 1859c9b1d098SAndrew Shewmaker static int __meminit init_user_reserve(void) 1860c9b1d098SAndrew Shewmaker { 1861c9b1d098SAndrew Shewmaker unsigned long free_kbytes; 1862c9b1d098SAndrew Shewmaker 1863c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 1864c9b1d098SAndrew Shewmaker 1865c9b1d098SAndrew Shewmaker sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17); 1866c9b1d098SAndrew Shewmaker return 0; 1867c9b1d098SAndrew Shewmaker } 1868a4bc6fc7SPaul Gortmaker subsys_initcall(init_user_reserve); 18694eeab4f5SAndrew Shewmaker 18704eeab4f5SAndrew Shewmaker /* 18714eeab4f5SAndrew Shewmaker * Initialise sysctl_admin_reserve_kbytes. 18724eeab4f5SAndrew Shewmaker * 18734eeab4f5SAndrew Shewmaker * The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin 18744eeab4f5SAndrew Shewmaker * to log in and kill a memory hogging process. 18754eeab4f5SAndrew Shewmaker * 18764eeab4f5SAndrew Shewmaker * Systems with more than 256MB will reserve 8MB, enough to recover 18774eeab4f5SAndrew Shewmaker * with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will 18784eeab4f5SAndrew Shewmaker * only reserve 3% of free pages by default. 18794eeab4f5SAndrew Shewmaker */ 18804eeab4f5SAndrew Shewmaker static int __meminit init_admin_reserve(void) 18814eeab4f5SAndrew Shewmaker { 18824eeab4f5SAndrew Shewmaker unsigned long free_kbytes; 18834eeab4f5SAndrew Shewmaker 1884c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 18854eeab4f5SAndrew Shewmaker 18864eeab4f5SAndrew Shewmaker sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13); 18874eeab4f5SAndrew Shewmaker return 0; 18884eeab4f5SAndrew Shewmaker } 1889a4bc6fc7SPaul Gortmaker subsys_initcall(init_admin_reserve); 1890