1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/mm/nommu.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Replacement code for mm functions to support CPU's that don't 61da177e4SLinus Torvalds * have any form of memory management unit (thus no virtual memory). 71da177e4SLinus Torvalds * 8dd19d293SStephen Kitt * See Documentation/admin-guide/mm/nommu-mmap.rst 91da177e4SLinus Torvalds * 108feae131SDavid Howells * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com> 111da177e4SLinus Torvalds * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> 121da177e4SLinus Torvalds * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> 131da177e4SLinus Torvalds * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> 1429c185e5SPaul Mundt * Copyright (c) 2007-2010 Paul Mundt <lethal@linux-sh.org> 151da177e4SLinus Torvalds */ 161da177e4SLinus Torvalds 17b1de0d13SMitchel Humpherys #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18b1de0d13SMitchel Humpherys 19b95f1b31SPaul Gortmaker #include <linux/export.h> 201da177e4SLinus Torvalds #include <linux/mm.h> 216e84f315SIngo Molnar #include <linux/sched/mm.h> 22615d6e87SDavidlohr Bueso #include <linux/vmacache.h> 231da177e4SLinus Torvalds #include <linux/mman.h> 241da177e4SLinus Torvalds #include <linux/swap.h> 251da177e4SLinus Torvalds #include <linux/file.h> 261da177e4SLinus Torvalds #include <linux/highmem.h> 271da177e4SLinus Torvalds #include <linux/pagemap.h> 281da177e4SLinus Torvalds #include <linux/slab.h> 291da177e4SLinus Torvalds #include <linux/vmalloc.h> 301da177e4SLinus Torvalds #include <linux/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 14388dca4caSChristoph Hellwig void *__vmalloc(unsigned long size, gfp_t gfp_mask) 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 153041de93fSChristoph Hellwig void *__vmalloc_node_range(unsigned long size, unsigned long align, 154041de93fSChristoph Hellwig unsigned long start, unsigned long end, gfp_t gfp_mask, 155041de93fSChristoph Hellwig pgprot_t prot, unsigned long vm_flags, int node, 156041de93fSChristoph Hellwig const void *caller) 157041de93fSChristoph Hellwig { 158041de93fSChristoph Hellwig return __vmalloc(size, gfp_mask); 159041de93fSChristoph Hellwig } 160041de93fSChristoph Hellwig 1612b905948SChristoph Hellwig void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, 1622b905948SChristoph Hellwig int node, const void *caller) 163a7c3e901SMichal Hocko { 1642b905948SChristoph Hellwig return __vmalloc(size, gfp_mask); 165a7c3e901SMichal Hocko } 166a7c3e901SMichal Hocko 167ed81745aSAndrii Nakryiko static void *__vmalloc_user_flags(unsigned long size, gfp_t flags) 168f905bc44SPaul Mundt { 169f905bc44SPaul Mundt void *ret; 170f905bc44SPaul Mundt 17188dca4caSChristoph Hellwig ret = __vmalloc(size, flags); 172f905bc44SPaul Mundt if (ret) { 173f905bc44SPaul Mundt struct vm_area_struct *vma; 174f905bc44SPaul Mundt 175d8ed45c5SMichel Lespinasse mmap_write_lock(current->mm); 176f905bc44SPaul Mundt vma = find_vma(current->mm, (unsigned long)ret); 177f905bc44SPaul Mundt if (vma) 178f905bc44SPaul Mundt vma->vm_flags |= VM_USERMAP; 179d8ed45c5SMichel Lespinasse mmap_write_unlock(current->mm); 180f905bc44SPaul Mundt } 181f905bc44SPaul Mundt 182f905bc44SPaul Mundt return ret; 183f905bc44SPaul Mundt } 184ed81745aSAndrii Nakryiko 185ed81745aSAndrii Nakryiko void *vmalloc_user(unsigned long size) 186ed81745aSAndrii Nakryiko { 187ed81745aSAndrii Nakryiko return __vmalloc_user_flags(size, GFP_KERNEL | __GFP_ZERO); 188ed81745aSAndrii Nakryiko } 189f905bc44SPaul Mundt EXPORT_SYMBOL(vmalloc_user); 190f905bc44SPaul Mundt 191b3bdda02SChristoph Lameter struct page *vmalloc_to_page(const void *addr) 1921da177e4SLinus Torvalds { 1931da177e4SLinus Torvalds return virt_to_page(addr); 1941da177e4SLinus Torvalds } 195b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_page); 1961da177e4SLinus Torvalds 197b3bdda02SChristoph Lameter unsigned long vmalloc_to_pfn(const void *addr) 1981da177e4SLinus Torvalds { 1991da177e4SLinus Torvalds return page_to_pfn(virt_to_page(addr)); 2001da177e4SLinus Torvalds } 201b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_to_pfn); 2021da177e4SLinus Torvalds 2031da177e4SLinus Torvalds long vread(char *buf, char *addr, unsigned long count) 2041da177e4SLinus Torvalds { 2059bde916bSChen Gang /* Don't allow overflow */ 2069bde916bSChen Gang if ((unsigned long) buf + count < count) 2079bde916bSChen Gang count = -(unsigned long) buf; 2089bde916bSChen Gang 2091da177e4SLinus Torvalds memcpy(buf, addr, count); 2101da177e4SLinus Torvalds return count; 2111da177e4SLinus Torvalds } 2121da177e4SLinus Torvalds 2131da177e4SLinus Torvalds long vwrite(char *buf, char *addr, unsigned long count) 2141da177e4SLinus Torvalds { 2151da177e4SLinus Torvalds /* Don't allow overflow */ 2161da177e4SLinus Torvalds if ((unsigned long) addr + count < count) 2171da177e4SLinus Torvalds count = -(unsigned long) addr; 2181da177e4SLinus Torvalds 2191da177e4SLinus Torvalds memcpy(addr, buf, count); 220ac714904SChoi Gi-yong return count; 2211da177e4SLinus Torvalds } 2221da177e4SLinus Torvalds 2231da177e4SLinus Torvalds /* 224e1c05067SMasahiro Yamada * vmalloc - allocate virtually contiguous memory 2251da177e4SLinus Torvalds * 2261da177e4SLinus Torvalds * @size: allocation size 2271da177e4SLinus Torvalds * 2281da177e4SLinus Torvalds * Allocate enough pages to cover @size from the page level 229e1c05067SMasahiro Yamada * allocator and map them into contiguous kernel virtual space. 2301da177e4SLinus Torvalds * 231c1c8897fSMichael Opdenacker * For tight control over page level allocator and protection flags 2321da177e4SLinus Torvalds * use __vmalloc() instead. 2331da177e4SLinus Torvalds */ 2341da177e4SLinus Torvalds void *vmalloc(unsigned long size) 2351da177e4SLinus Torvalds { 23688dca4caSChristoph Hellwig return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM); 2371da177e4SLinus Torvalds } 238f6138882SAndrew Morton EXPORT_SYMBOL(vmalloc); 239f6138882SAndrew Morton 240e1ca7788SDave Young /* 241e1c05067SMasahiro Yamada * vzalloc - allocate virtually contiguous memory with zero fill 242e1ca7788SDave Young * 243e1ca7788SDave Young * @size: allocation size 244e1ca7788SDave Young * 245e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 246e1c05067SMasahiro Yamada * allocator and map them into contiguous kernel virtual space. 247e1ca7788SDave Young * The memory allocated is set to zero. 248e1ca7788SDave Young * 249e1ca7788SDave Young * For tight control over page level allocator and protection flags 250e1ca7788SDave Young * use __vmalloc() instead. 251e1ca7788SDave Young */ 252e1ca7788SDave Young void *vzalloc(unsigned long size) 253e1ca7788SDave Young { 25488dca4caSChristoph Hellwig return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO); 255e1ca7788SDave Young } 256e1ca7788SDave Young EXPORT_SYMBOL(vzalloc); 257e1ca7788SDave Young 258e1ca7788SDave Young /** 259e1ca7788SDave Young * vmalloc_node - allocate memory on a specific node 260e1ca7788SDave Young * @size: allocation size 261e1ca7788SDave Young * @node: numa node 262e1ca7788SDave Young * 263e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 264e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 265e1ca7788SDave Young * 266e1ca7788SDave Young * For tight control over page level allocator and protection flags 267e1ca7788SDave Young * use __vmalloc() instead. 268e1ca7788SDave Young */ 269f6138882SAndrew Morton void *vmalloc_node(unsigned long size, int node) 270f6138882SAndrew Morton { 271f6138882SAndrew Morton return vmalloc(size); 272f6138882SAndrew Morton } 2739a14f653SPaul Mundt EXPORT_SYMBOL(vmalloc_node); 274e1ca7788SDave Young 275e1ca7788SDave Young /** 276e1ca7788SDave Young * vzalloc_node - allocate memory on a specific node with zero fill 277e1ca7788SDave Young * @size: allocation size 278e1ca7788SDave Young * @node: numa node 279e1ca7788SDave Young * 280e1ca7788SDave Young * Allocate enough pages to cover @size from the page level 281e1ca7788SDave Young * allocator and map them into contiguous kernel virtual space. 282e1ca7788SDave Young * The memory allocated is set to zero. 283e1ca7788SDave Young * 284e1ca7788SDave Young * For tight control over page level allocator and protection flags 285e1ca7788SDave Young * use __vmalloc() instead. 286e1ca7788SDave Young */ 287e1ca7788SDave Young void *vzalloc_node(unsigned long size, int node) 288e1ca7788SDave Young { 289e1ca7788SDave Young return vzalloc(size); 290e1ca7788SDave Young } 291e1ca7788SDave Young EXPORT_SYMBOL(vzalloc_node); 2921da177e4SLinus Torvalds 2931af446edSPaul Mundt /** 294b5073173SPaul Mundt * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 2951da177e4SLinus Torvalds * @size: allocation size 2961da177e4SLinus Torvalds * 2971da177e4SLinus Torvalds * Allocate enough 32bit PA addressable pages to cover @size from the 298e1c05067SMasahiro Yamada * page level allocator and map them into contiguous kernel virtual space. 2991da177e4SLinus Torvalds */ 3001da177e4SLinus Torvalds void *vmalloc_32(unsigned long size) 3011da177e4SLinus Torvalds { 30288dca4caSChristoph Hellwig return __vmalloc(size, GFP_KERNEL); 3031da177e4SLinus Torvalds } 304b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32); 305b5073173SPaul Mundt 306b5073173SPaul Mundt /** 307b5073173SPaul Mundt * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 308b5073173SPaul Mundt * @size: allocation size 309b5073173SPaul Mundt * 310b5073173SPaul Mundt * The resulting memory area is 32bit addressable and zeroed so it can be 311b5073173SPaul Mundt * mapped to userspace without leaking data. 312f905bc44SPaul Mundt * 313f905bc44SPaul Mundt * VM_USERMAP is set on the corresponding VMA so that subsequent calls to 314f905bc44SPaul Mundt * remap_vmalloc_range() are permissible. 315b5073173SPaul Mundt */ 316b5073173SPaul Mundt void *vmalloc_32_user(unsigned long size) 317b5073173SPaul Mundt { 318f905bc44SPaul Mundt /* 319f905bc44SPaul Mundt * We'll have to sort out the ZONE_DMA bits for 64-bit, 320f905bc44SPaul Mundt * but for now this can simply use vmalloc_user() directly. 321f905bc44SPaul Mundt */ 322f905bc44SPaul Mundt return vmalloc_user(size); 323b5073173SPaul Mundt } 324b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32_user); 3251da177e4SLinus Torvalds 3261da177e4SLinus Torvalds void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) 3271da177e4SLinus Torvalds { 3281da177e4SLinus Torvalds BUG(); 3291da177e4SLinus Torvalds return NULL; 3301da177e4SLinus Torvalds } 331b5073173SPaul Mundt EXPORT_SYMBOL(vmap); 3321da177e4SLinus Torvalds 333b3bdda02SChristoph Lameter void vunmap(const void *addr) 3341da177e4SLinus Torvalds { 3351da177e4SLinus Torvalds BUG(); 3361da177e4SLinus Torvalds } 337b5073173SPaul Mundt EXPORT_SYMBOL(vunmap); 3381da177e4SLinus Torvalds 339d4efd79aSChristoph Hellwig void *vm_map_ram(struct page **pages, unsigned int count, int node) 340eb6434d9SPaul Mundt { 341eb6434d9SPaul Mundt BUG(); 342eb6434d9SPaul Mundt return NULL; 343eb6434d9SPaul Mundt } 344eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_map_ram); 345eb6434d9SPaul Mundt 346eb6434d9SPaul Mundt void vm_unmap_ram(const void *mem, unsigned int count) 347eb6434d9SPaul Mundt { 348eb6434d9SPaul Mundt BUG(); 349eb6434d9SPaul Mundt } 350eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_unmap_ram); 351eb6434d9SPaul Mundt 352eb6434d9SPaul Mundt void vm_unmap_aliases(void) 353eb6434d9SPaul Mundt { 354eb6434d9SPaul Mundt } 355eb6434d9SPaul Mundt EXPORT_SYMBOL_GPL(vm_unmap_aliases); 356eb6434d9SPaul Mundt 35729c185e5SPaul Mundt void free_vm_area(struct vm_struct *area) 35829c185e5SPaul Mundt { 35929c185e5SPaul Mundt BUG(); 36029c185e5SPaul Mundt } 36129c185e5SPaul Mundt EXPORT_SYMBOL_GPL(free_vm_area); 36229c185e5SPaul Mundt 363b5073173SPaul Mundt int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 364b5073173SPaul Mundt struct page *page) 365b5073173SPaul Mundt { 366b5073173SPaul Mundt return -EINVAL; 367b5073173SPaul Mundt } 368b5073173SPaul Mundt EXPORT_SYMBOL(vm_insert_page); 369b5073173SPaul Mundt 370a667d745SSouptick Joarder int vm_map_pages(struct vm_area_struct *vma, struct page **pages, 371a667d745SSouptick Joarder unsigned long num) 372a667d745SSouptick Joarder { 373a667d745SSouptick Joarder return -EINVAL; 374a667d745SSouptick Joarder } 375a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages); 376a667d745SSouptick Joarder 377a667d745SSouptick Joarder int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, 378a667d745SSouptick Joarder unsigned long num) 379a667d745SSouptick Joarder { 380a667d745SSouptick Joarder return -EINVAL; 381a667d745SSouptick Joarder } 382a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages_zero); 383a667d745SSouptick Joarder 3841eeb66a1SChristoph Hellwig /* 3851da177e4SLinus Torvalds * sys_brk() for the most part doesn't need the global kernel 3861da177e4SLinus Torvalds * lock, except when an application is doing something nasty 3871da177e4SLinus Torvalds * like trying to un-brk an area that has already been mapped 3881da177e4SLinus Torvalds * to a regular file. in this case, the unmapping will need 3891da177e4SLinus Torvalds * to invoke file system routines that need the global lock. 3901da177e4SLinus Torvalds */ 3916a6160a7SHeiko Carstens SYSCALL_DEFINE1(brk, unsigned long, brk) 3921da177e4SLinus Torvalds { 3931da177e4SLinus Torvalds struct mm_struct *mm = current->mm; 3941da177e4SLinus Torvalds 3951da177e4SLinus Torvalds if (brk < mm->start_brk || brk > mm->context.end_brk) 3961da177e4SLinus Torvalds return mm->brk; 3971da177e4SLinus Torvalds 3981da177e4SLinus Torvalds if (mm->brk == brk) 3991da177e4SLinus Torvalds return mm->brk; 4001da177e4SLinus Torvalds 4011da177e4SLinus Torvalds /* 4021da177e4SLinus Torvalds * Always allow shrinking brk 4031da177e4SLinus Torvalds */ 4041da177e4SLinus Torvalds if (brk <= mm->brk) { 4051da177e4SLinus Torvalds mm->brk = brk; 4061da177e4SLinus Torvalds return brk; 4071da177e4SLinus Torvalds } 4081da177e4SLinus Torvalds 4091da177e4SLinus Torvalds /* 4101da177e4SLinus Torvalds * Ok, looks good - let it rip. 4111da177e4SLinus Torvalds */ 412a75a2df6SChristoph Hellwig flush_icache_user_range(mm->brk, brk); 4131da177e4SLinus Torvalds return mm->brk = brk; 4141da177e4SLinus Torvalds } 4151da177e4SLinus Torvalds 4168feae131SDavid Howells /* 4173edf41d8Sseokhoon.yoon * initialise the percpu counter for VM and region record slabs 4188feae131SDavid Howells */ 4198feae131SDavid Howells void __init mmap_init(void) 4201da177e4SLinus Torvalds { 42100a62ce9SKOSAKI Motohiro int ret; 42200a62ce9SKOSAKI Motohiro 423908c7f19STejun Heo ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); 42400a62ce9SKOSAKI Motohiro VM_BUG_ON(ret); 4255d097056SVladimir Davydov vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC|SLAB_ACCOUNT); 4268feae131SDavid Howells } 4271da177e4SLinus Torvalds 4288feae131SDavid Howells /* 4298feae131SDavid Howells * validate the region tree 4308feae131SDavid Howells * - the caller must hold the region lock 4318feae131SDavid Howells */ 4328feae131SDavid Howells #ifdef CONFIG_DEBUG_NOMMU_REGIONS 4338feae131SDavid Howells static noinline void validate_nommu_regions(void) 4348feae131SDavid Howells { 4358feae131SDavid Howells struct vm_region *region, *last; 4368feae131SDavid Howells struct rb_node *p, *lastp; 4371da177e4SLinus Torvalds 4388feae131SDavid Howells lastp = rb_first(&nommu_region_tree); 4398feae131SDavid Howells if (!lastp) 4408feae131SDavid Howells return; 4418feae131SDavid Howells 4428feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 443c9427bc0SGeliang Tang BUG_ON(last->vm_end <= last->vm_start); 444c9427bc0SGeliang Tang BUG_ON(last->vm_top < last->vm_end); 4458feae131SDavid Howells 4468feae131SDavid Howells while ((p = rb_next(lastp))) { 4478feae131SDavid Howells region = rb_entry(p, struct vm_region, vm_rb); 4488feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 4498feae131SDavid Howells 450c9427bc0SGeliang Tang BUG_ON(region->vm_end <= region->vm_start); 451c9427bc0SGeliang Tang BUG_ON(region->vm_top < region->vm_end); 452c9427bc0SGeliang Tang BUG_ON(region->vm_start < last->vm_top); 4538feae131SDavid Howells 4548feae131SDavid Howells lastp = p; 4551da177e4SLinus Torvalds } 4561da177e4SLinus Torvalds } 4578feae131SDavid Howells #else 45833e5d769SDavid Howells static void validate_nommu_regions(void) 45933e5d769SDavid Howells { 46033e5d769SDavid Howells } 4618feae131SDavid Howells #endif 4628feae131SDavid Howells 4638feae131SDavid Howells /* 4648feae131SDavid Howells * add a region into the global tree 4658feae131SDavid Howells */ 4668feae131SDavid Howells static void add_nommu_region(struct vm_region *region) 4678feae131SDavid Howells { 4688feae131SDavid Howells struct vm_region *pregion; 4698feae131SDavid Howells struct rb_node **p, *parent; 4708feae131SDavid Howells 4718feae131SDavid Howells validate_nommu_regions(); 4728feae131SDavid Howells 4738feae131SDavid Howells parent = NULL; 4748feae131SDavid Howells p = &nommu_region_tree.rb_node; 4758feae131SDavid Howells while (*p) { 4768feae131SDavid Howells parent = *p; 4778feae131SDavid Howells pregion = rb_entry(parent, struct vm_region, vm_rb); 4788feae131SDavid Howells if (region->vm_start < pregion->vm_start) 4798feae131SDavid Howells p = &(*p)->rb_left; 4808feae131SDavid Howells else if (region->vm_start > pregion->vm_start) 4818feae131SDavid Howells p = &(*p)->rb_right; 4828feae131SDavid Howells else if (pregion == region) 4838feae131SDavid Howells return; 4848feae131SDavid Howells else 4858feae131SDavid Howells BUG(); 4868feae131SDavid Howells } 4878feae131SDavid Howells 4888feae131SDavid Howells rb_link_node(®ion->vm_rb, parent, p); 4898feae131SDavid Howells rb_insert_color(®ion->vm_rb, &nommu_region_tree); 4908feae131SDavid Howells 4918feae131SDavid Howells validate_nommu_regions(); 4928feae131SDavid Howells } 4938feae131SDavid Howells 4948feae131SDavid Howells /* 4958feae131SDavid Howells * delete a region from the global tree 4968feae131SDavid Howells */ 4978feae131SDavid Howells static void delete_nommu_region(struct vm_region *region) 4988feae131SDavid Howells { 4998feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5008feae131SDavid Howells 5018feae131SDavid Howells validate_nommu_regions(); 5028feae131SDavid Howells rb_erase(®ion->vm_rb, &nommu_region_tree); 5038feae131SDavid Howells validate_nommu_regions(); 5048feae131SDavid Howells } 5058feae131SDavid Howells 5068feae131SDavid Howells /* 5078feae131SDavid Howells * free a contiguous series of pages 5088feae131SDavid Howells */ 5098feae131SDavid Howells static void free_page_series(unsigned long from, unsigned long to) 5108feae131SDavid Howells { 5118feae131SDavid Howells for (; from < to; from += PAGE_SIZE) { 5128feae131SDavid Howells struct page *page = virt_to_page(from); 5138feae131SDavid Howells 51433e5d769SDavid Howells atomic_long_dec(&mmap_pages_allocated); 5158feae131SDavid Howells put_page(page); 5168feae131SDavid Howells } 5178feae131SDavid Howells } 5188feae131SDavid Howells 5198feae131SDavid Howells /* 5208feae131SDavid Howells * release a reference to a region 52133e5d769SDavid Howells * - the caller must hold the region semaphore for writing, which this releases 522dd8632a1SPaul Mundt * - the region may not have been added to the tree yet, in which case vm_top 5238feae131SDavid Howells * will equal vm_start 5248feae131SDavid Howells */ 5258feae131SDavid Howells static void __put_nommu_region(struct vm_region *region) 5268feae131SDavid Howells __releases(nommu_region_sem) 5278feae131SDavid Howells { 5288feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5298feae131SDavid Howells 5301e2ae599SDavid Howells if (--region->vm_usage == 0) { 531dd8632a1SPaul Mundt if (region->vm_top > region->vm_start) 5328feae131SDavid Howells delete_nommu_region(region); 5338feae131SDavid Howells up_write(&nommu_region_sem); 5348feae131SDavid Howells 5358feae131SDavid Howells if (region->vm_file) 5368feae131SDavid Howells fput(region->vm_file); 5378feae131SDavid Howells 5388feae131SDavid Howells /* IO memory and memory shared directly out of the pagecache 5398feae131SDavid Howells * from ramfs/tmpfs mustn't be released here */ 54022cc877bSLeon Romanovsky if (region->vm_flags & VM_MAPPED_COPY) 541dd8632a1SPaul Mundt free_page_series(region->vm_start, region->vm_top); 5428feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 5438feae131SDavid Howells } else { 5448feae131SDavid Howells up_write(&nommu_region_sem); 5458feae131SDavid Howells } 5468feae131SDavid Howells } 5478feae131SDavid Howells 5488feae131SDavid Howells /* 5498feae131SDavid Howells * release a reference to a region 5508feae131SDavid Howells */ 5518feae131SDavid Howells static void put_nommu_region(struct vm_region *region) 5528feae131SDavid Howells { 5538feae131SDavid Howells down_write(&nommu_region_sem); 5548feae131SDavid Howells __put_nommu_region(region); 5558feae131SDavid Howells } 5561da177e4SLinus Torvalds 5573034097aSDavid Howells /* 5583034097aSDavid Howells * add a VMA into a process's mm_struct in the appropriate place in the list 5598feae131SDavid Howells * and tree and add to the address space's page tree also if not an anonymous 5608feae131SDavid Howells * page 561c1e8d7c6SMichel Lespinasse * - should be called with mm->mmap_lock held writelocked 5623034097aSDavid Howells */ 5638feae131SDavid Howells static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) 5643034097aSDavid Howells { 5656038def0SNamhyung Kim struct vm_area_struct *pvma, *prev; 5668feae131SDavid Howells struct address_space *mapping; 5676038def0SNamhyung Kim struct rb_node **p, *parent, *rb_prev; 5683034097aSDavid Howells 5698feae131SDavid Howells BUG_ON(!vma->vm_region); 5708feae131SDavid Howells 5718feae131SDavid Howells mm->map_count++; 5728feae131SDavid Howells vma->vm_mm = mm; 5738feae131SDavid Howells 5748feae131SDavid Howells /* add the VMA to the mapping */ 5758feae131SDavid Howells if (vma->vm_file) { 5768feae131SDavid Howells mapping = vma->vm_file->f_mapping; 5778feae131SDavid Howells 57883cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 5798feae131SDavid Howells flush_dcache_mmap_lock(mapping); 5806b2dbba8SMichel Lespinasse vma_interval_tree_insert(vma, &mapping->i_mmap); 5818feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 58283cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 5838feae131SDavid Howells } 5848feae131SDavid Howells 5858feae131SDavid Howells /* add the VMA to the tree */ 5866038def0SNamhyung Kim parent = rb_prev = NULL; 5878feae131SDavid Howells p = &mm->mm_rb.rb_node; 5888feae131SDavid Howells while (*p) { 5898feae131SDavid Howells parent = *p; 5908feae131SDavid Howells pvma = rb_entry(parent, struct vm_area_struct, vm_rb); 5918feae131SDavid Howells 5928feae131SDavid Howells /* sort by: start addr, end addr, VMA struct addr in that order 5938feae131SDavid Howells * (the latter is necessary as we may get identical VMAs) */ 5948feae131SDavid Howells if (vma->vm_start < pvma->vm_start) 5958feae131SDavid Howells p = &(*p)->rb_left; 5966038def0SNamhyung Kim else if (vma->vm_start > pvma->vm_start) { 5976038def0SNamhyung Kim rb_prev = parent; 5988feae131SDavid Howells p = &(*p)->rb_right; 5996038def0SNamhyung Kim } else if (vma->vm_end < pvma->vm_end) 6008feae131SDavid Howells p = &(*p)->rb_left; 6016038def0SNamhyung Kim else if (vma->vm_end > pvma->vm_end) { 6026038def0SNamhyung Kim rb_prev = parent; 6038feae131SDavid Howells p = &(*p)->rb_right; 6046038def0SNamhyung Kim } else if (vma < pvma) 6058feae131SDavid Howells p = &(*p)->rb_left; 6066038def0SNamhyung Kim else if (vma > pvma) { 6076038def0SNamhyung Kim rb_prev = parent; 6088feae131SDavid Howells p = &(*p)->rb_right; 6096038def0SNamhyung Kim } else 6108feae131SDavid Howells BUG(); 6118feae131SDavid Howells } 6128feae131SDavid Howells 6138feae131SDavid Howells rb_link_node(&vma->vm_rb, parent, p); 6148feae131SDavid Howells rb_insert_color(&vma->vm_rb, &mm->mm_rb); 6158feae131SDavid Howells 6168feae131SDavid Howells /* add VMA to the VMA list also */ 6176038def0SNamhyung Kim prev = NULL; 6186038def0SNamhyung Kim if (rb_prev) 6196038def0SNamhyung Kim prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); 6203034097aSDavid Howells 621aba6dfb7SWei Yang __vma_link_list(mm, vma, prev); 6228feae131SDavid Howells } 6238feae131SDavid Howells 6248feae131SDavid Howells /* 6258feae131SDavid Howells * delete a VMA from its owning mm_struct and address space 6268feae131SDavid Howells */ 6278feae131SDavid Howells static void delete_vma_from_mm(struct vm_area_struct *vma) 6288feae131SDavid Howells { 629615d6e87SDavidlohr Bueso int i; 6308feae131SDavid Howells struct address_space *mapping; 6318feae131SDavid Howells struct mm_struct *mm = vma->vm_mm; 632615d6e87SDavidlohr Bueso struct task_struct *curr = current; 6338feae131SDavid Howells 6348feae131SDavid Howells mm->map_count--; 635615d6e87SDavidlohr Bueso for (i = 0; i < VMACACHE_SIZE; i++) { 636615d6e87SDavidlohr Bueso /* if the vma is cached, invalidate the entire cache */ 637314ff785SIngo Molnar if (curr->vmacache.vmas[i] == vma) { 638e020d5bdSSteven Miao vmacache_invalidate(mm); 639615d6e87SDavidlohr Bueso break; 640615d6e87SDavidlohr Bueso } 641615d6e87SDavidlohr Bueso } 6428feae131SDavid Howells 6438feae131SDavid Howells /* remove the VMA from the mapping */ 6448feae131SDavid Howells if (vma->vm_file) { 6458feae131SDavid Howells mapping = vma->vm_file->f_mapping; 6468feae131SDavid Howells 64783cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 6488feae131SDavid Howells flush_dcache_mmap_lock(mapping); 6496b2dbba8SMichel Lespinasse vma_interval_tree_remove(vma, &mapping->i_mmap); 6508feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 65183cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 6528feae131SDavid Howells } 6538feae131SDavid Howells 6548feae131SDavid Howells /* remove from the MM's tree and list */ 6558feae131SDavid Howells rb_erase(&vma->vm_rb, &mm->mm_rb); 656b951bf2cSNamhyung Kim 6571b9fc5b2SWei Yang __vma_unlink_list(mm, vma); 6588feae131SDavid Howells } 6598feae131SDavid Howells 6608feae131SDavid Howells /* 6618feae131SDavid Howells * destroy a VMA record 6628feae131SDavid Howells */ 6638feae131SDavid Howells static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) 6648feae131SDavid Howells { 6658feae131SDavid Howells if (vma->vm_ops && vma->vm_ops->close) 6668feae131SDavid Howells vma->vm_ops->close(vma); 667e9714acfSKonstantin Khlebnikov if (vma->vm_file) 6688feae131SDavid Howells fput(vma->vm_file); 6698feae131SDavid Howells put_nommu_region(vma->vm_region); 6703928d4f5SLinus Torvalds vm_area_free(vma); 6713034097aSDavid Howells } 6723034097aSDavid Howells 6733034097aSDavid Howells /* 6743034097aSDavid Howells * look up the first VMA in which addr resides, NULL if none 675c1e8d7c6SMichel Lespinasse * - should be called with mm->mmap_lock at least held readlocked 6763034097aSDavid Howells */ 6773034097aSDavid Howells struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) 6783034097aSDavid Howells { 6798feae131SDavid Howells struct vm_area_struct *vma; 6803034097aSDavid Howells 6818feae131SDavid Howells /* check the cache first */ 682615d6e87SDavidlohr Bueso vma = vmacache_find(mm, addr); 683615d6e87SDavidlohr Bueso if (likely(vma)) 6848feae131SDavid Howells return vma; 6858feae131SDavid Howells 686e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 6878feae131SDavid Howells * resides) */ 688e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 6898feae131SDavid Howells if (vma->vm_start > addr) 6908feae131SDavid Howells return NULL; 6918feae131SDavid Howells if (vma->vm_end > addr) { 692615d6e87SDavidlohr Bueso vmacache_update(addr, vma); 6938feae131SDavid Howells return vma; 6943034097aSDavid Howells } 6958feae131SDavid Howells } 6963034097aSDavid Howells 6973034097aSDavid Howells return NULL; 6983034097aSDavid Howells } 6993034097aSDavid Howells EXPORT_SYMBOL(find_vma); 7003034097aSDavid Howells 7013034097aSDavid Howells /* 702930e652aSDavid Howells * find a VMA 703930e652aSDavid Howells * - we don't extend stack VMAs under NOMMU conditions 704930e652aSDavid Howells */ 705930e652aSDavid Howells struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) 706930e652aSDavid Howells { 7077561e8caSDavid Howells return find_vma(mm, addr); 708930e652aSDavid Howells } 709930e652aSDavid Howells 7108feae131SDavid Howells /* 7118feae131SDavid Howells * expand a stack to a given address 7128feae131SDavid Howells * - not supported under NOMMU conditions 7138feae131SDavid Howells */ 71457c8f63eSGreg Ungerer int expand_stack(struct vm_area_struct *vma, unsigned long address) 71557c8f63eSGreg Ungerer { 71657c8f63eSGreg Ungerer return -ENOMEM; 71757c8f63eSGreg Ungerer } 71857c8f63eSGreg Ungerer 719930e652aSDavid Howells /* 7206fa5f80bSDavid Howells * look up the first VMA exactly that exactly matches addr 721c1e8d7c6SMichel Lespinasse * - should be called with mm->mmap_lock at least held readlocked 7226fa5f80bSDavid Howells */ 7238feae131SDavid Howells static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, 7248feae131SDavid Howells unsigned long addr, 7258feae131SDavid Howells unsigned long len) 7261da177e4SLinus Torvalds { 7271da177e4SLinus Torvalds struct vm_area_struct *vma; 7288feae131SDavid Howells unsigned long end = addr + len; 7291da177e4SLinus Torvalds 7308feae131SDavid Howells /* check the cache first */ 731615d6e87SDavidlohr Bueso vma = vmacache_find_exact(mm, addr, end); 732615d6e87SDavidlohr Bueso if (vma) 7331da177e4SLinus Torvalds return vma; 7348feae131SDavid Howells 735e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 7368feae131SDavid Howells * resides) */ 737e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 7388feae131SDavid Howells if (vma->vm_start < addr) 7398feae131SDavid Howells continue; 7408feae131SDavid Howells if (vma->vm_start > addr) 7418feae131SDavid Howells return NULL; 7428feae131SDavid Howells if (vma->vm_end == end) { 743615d6e87SDavidlohr Bueso vmacache_update(addr, vma); 7448feae131SDavid Howells return vma; 7458feae131SDavid Howells } 7461da177e4SLinus Torvalds } 7471da177e4SLinus Torvalds 7481da177e4SLinus Torvalds return NULL; 7491da177e4SLinus Torvalds } 7501da177e4SLinus Torvalds 7513034097aSDavid Howells /* 7521da177e4SLinus Torvalds * determine whether a mapping should be permitted and, if so, what sort of 7531da177e4SLinus Torvalds * mapping we're capable of supporting 7541da177e4SLinus Torvalds */ 7551da177e4SLinus Torvalds static int validate_mmap_request(struct file *file, 7561da177e4SLinus Torvalds unsigned long addr, 7571da177e4SLinus Torvalds unsigned long len, 7581da177e4SLinus Torvalds unsigned long prot, 7591da177e4SLinus Torvalds unsigned long flags, 7601da177e4SLinus Torvalds unsigned long pgoff, 7611da177e4SLinus Torvalds unsigned long *_capabilities) 7621da177e4SLinus Torvalds { 7638feae131SDavid Howells unsigned long capabilities, rlen; 7641da177e4SLinus Torvalds int ret; 7651da177e4SLinus Torvalds 7661da177e4SLinus Torvalds /* do the simple checks first */ 76722cc877bSLeon Romanovsky if (flags & MAP_FIXED) 7681da177e4SLinus Torvalds return -EINVAL; 7691da177e4SLinus Torvalds 7701da177e4SLinus Torvalds if ((flags & MAP_TYPE) != MAP_PRIVATE && 7711da177e4SLinus Torvalds (flags & MAP_TYPE) != MAP_SHARED) 7721da177e4SLinus Torvalds return -EINVAL; 7731da177e4SLinus Torvalds 774f81cff0dSMike Frysinger if (!len) 7751da177e4SLinus Torvalds return -EINVAL; 7761da177e4SLinus Torvalds 777f81cff0dSMike Frysinger /* Careful about overflows.. */ 7788feae131SDavid Howells rlen = PAGE_ALIGN(len); 7798feae131SDavid Howells if (!rlen || rlen > TASK_SIZE) 780f81cff0dSMike Frysinger return -ENOMEM; 781f81cff0dSMike Frysinger 7821da177e4SLinus Torvalds /* offset overflow? */ 7838feae131SDavid Howells if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) 784f81cff0dSMike Frysinger return -EOVERFLOW; 7851da177e4SLinus Torvalds 7861da177e4SLinus Torvalds if (file) { 7871da177e4SLinus Torvalds /* files must support mmap */ 78872c2d531SAl Viro if (!file->f_op->mmap) 7891da177e4SLinus Torvalds return -ENODEV; 7901da177e4SLinus Torvalds 7911da177e4SLinus Torvalds /* work out if what we've got could possibly be shared 7921da177e4SLinus Torvalds * - we support chardevs that provide their own "memory" 7931da177e4SLinus Torvalds * - we support files/blockdevs that are memory backed 7941da177e4SLinus Torvalds */ 795b4caecd4SChristoph Hellwig if (file->f_op->mmap_capabilities) { 796b4caecd4SChristoph Hellwig capabilities = file->f_op->mmap_capabilities(file); 797b4caecd4SChristoph Hellwig } else { 7981da177e4SLinus Torvalds /* no explicit capabilities set, so assume some 7991da177e4SLinus Torvalds * defaults */ 800496ad9aaSAl Viro switch (file_inode(file)->i_mode & S_IFMT) { 8011da177e4SLinus Torvalds case S_IFREG: 8021da177e4SLinus Torvalds case S_IFBLK: 803b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 8041da177e4SLinus Torvalds break; 8051da177e4SLinus Torvalds 8061da177e4SLinus Torvalds case S_IFCHR: 8071da177e4SLinus Torvalds capabilities = 808b4caecd4SChristoph Hellwig NOMMU_MAP_DIRECT | 809b4caecd4SChristoph Hellwig NOMMU_MAP_READ | 810b4caecd4SChristoph Hellwig NOMMU_MAP_WRITE; 8111da177e4SLinus Torvalds break; 8121da177e4SLinus Torvalds 8131da177e4SLinus Torvalds default: 8141da177e4SLinus Torvalds return -EINVAL; 8151da177e4SLinus Torvalds } 8161da177e4SLinus Torvalds } 8171da177e4SLinus Torvalds 8181da177e4SLinus Torvalds /* eliminate any capabilities that we can't support on this 8191da177e4SLinus Torvalds * device */ 8201da177e4SLinus Torvalds if (!file->f_op->get_unmapped_area) 821b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8226e242a1cSAl Viro if (!(file->f_mode & FMODE_CAN_READ)) 823b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 8241da177e4SLinus Torvalds 82528d7a6aeSGraff Yang /* The file shall have been opened with read permission. */ 82628d7a6aeSGraff Yang if (!(file->f_mode & FMODE_READ)) 82728d7a6aeSGraff Yang return -EACCES; 82828d7a6aeSGraff Yang 8291da177e4SLinus Torvalds if (flags & MAP_SHARED) { 8301da177e4SLinus Torvalds /* do checks for writing, appending and locking */ 8311da177e4SLinus Torvalds if ((prot & PROT_WRITE) && 8321da177e4SLinus Torvalds !(file->f_mode & FMODE_WRITE)) 8331da177e4SLinus Torvalds return -EACCES; 8341da177e4SLinus Torvalds 835496ad9aaSAl Viro if (IS_APPEND(file_inode(file)) && 8361da177e4SLinus Torvalds (file->f_mode & FMODE_WRITE)) 8371da177e4SLinus Torvalds return -EACCES; 8381da177e4SLinus Torvalds 839d7a06983SJeff Layton if (locks_verify_locked(file)) 8401da177e4SLinus Torvalds return -EAGAIN; 8411da177e4SLinus Torvalds 842b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 8431da177e4SLinus Torvalds return -ENODEV; 8441da177e4SLinus Torvalds 8451da177e4SLinus Torvalds /* we mustn't privatise shared mappings */ 846b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 847ac714904SChoi Gi-yong } else { 8481da177e4SLinus Torvalds /* we're going to read the file into private memory we 8491da177e4SLinus Torvalds * allocate */ 850b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 8511da177e4SLinus Torvalds return -ENODEV; 8521da177e4SLinus Torvalds 8531da177e4SLinus Torvalds /* we don't permit a private writable mapping to be 8541da177e4SLinus Torvalds * shared with the backing device */ 8551da177e4SLinus Torvalds if (prot & PROT_WRITE) 856b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8571da177e4SLinus Torvalds } 8581da177e4SLinus Torvalds 859b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 860b4caecd4SChristoph Hellwig if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) || 861b4caecd4SChristoph Hellwig ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) || 862b4caecd4SChristoph Hellwig ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC)) 8633c7b2045SBernd Schmidt ) { 864b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8653c7b2045SBernd Schmidt if (flags & MAP_SHARED) { 86622cc877bSLeon Romanovsky pr_warn("MAP_SHARED not completely supported on !MMU\n"); 8673c7b2045SBernd Schmidt return -EINVAL; 8683c7b2045SBernd Schmidt } 8693c7b2045SBernd Schmidt } 8703c7b2045SBernd Schmidt } 8713c7b2045SBernd Schmidt 8721da177e4SLinus Torvalds /* handle executable mappings and implied executable 8731da177e4SLinus Torvalds * mappings */ 87490f8572bSEric W. Biederman if (path_noexec(&file->f_path)) { 8751da177e4SLinus Torvalds if (prot & PROT_EXEC) 8761da177e4SLinus Torvalds return -EPERM; 877ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { 8781da177e4SLinus Torvalds /* handle implication of PROT_EXEC by PROT_READ */ 8791da177e4SLinus Torvalds if (current->personality & READ_IMPLIES_EXEC) { 880b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_EXEC) 8811da177e4SLinus Torvalds prot |= PROT_EXEC; 8821da177e4SLinus Torvalds } 883ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && 8841da177e4SLinus Torvalds (prot & PROT_EXEC) && 885b4caecd4SChristoph Hellwig !(capabilities & NOMMU_MAP_EXEC) 8861da177e4SLinus Torvalds ) { 8871da177e4SLinus Torvalds /* backing file is not executable, try to copy */ 888b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8891da177e4SLinus Torvalds } 890ac714904SChoi Gi-yong } else { 8911da177e4SLinus Torvalds /* anonymous mappings are always memory backed and can be 8921da177e4SLinus Torvalds * privately mapped 8931da177e4SLinus Torvalds */ 894b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 8951da177e4SLinus Torvalds 8961da177e4SLinus Torvalds /* handle PROT_EXEC implication by PROT_READ */ 8971da177e4SLinus Torvalds if ((prot & PROT_READ) && 8981da177e4SLinus Torvalds (current->personality & READ_IMPLIES_EXEC)) 8991da177e4SLinus Torvalds prot |= PROT_EXEC; 9001da177e4SLinus Torvalds } 9011da177e4SLinus Torvalds 9021da177e4SLinus Torvalds /* allow the security API to have its say */ 903e5467859SAl Viro ret = security_mmap_addr(addr); 904e5467859SAl Viro if (ret < 0) 905e5467859SAl Viro return ret; 9061da177e4SLinus Torvalds 9071da177e4SLinus Torvalds /* looks okay */ 9081da177e4SLinus Torvalds *_capabilities = capabilities; 9091da177e4SLinus Torvalds return 0; 9101da177e4SLinus Torvalds } 9111da177e4SLinus Torvalds 9121da177e4SLinus Torvalds /* 9131da177e4SLinus Torvalds * we've determined that we can make the mapping, now translate what we 9141da177e4SLinus Torvalds * now know into VMA flags 9151da177e4SLinus Torvalds */ 9161da177e4SLinus Torvalds static unsigned long determine_vm_flags(struct file *file, 9171da177e4SLinus Torvalds unsigned long prot, 9181da177e4SLinus Torvalds unsigned long flags, 9191da177e4SLinus Torvalds unsigned long capabilities) 9201da177e4SLinus Torvalds { 9211da177e4SLinus Torvalds unsigned long vm_flags; 9221da177e4SLinus Torvalds 923e6bfb709SDave Hansen vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags); 9241da177e4SLinus Torvalds /* vm_flags |= mm->def_flags; */ 9251da177e4SLinus Torvalds 926b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) { 9271da177e4SLinus Torvalds /* attempt to share read-only copies of mapped file chunks */ 9283c7b2045SBernd Schmidt vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; 9291da177e4SLinus Torvalds if (file && !(prot & PROT_WRITE)) 9301da177e4SLinus Torvalds vm_flags |= VM_MAYSHARE; 9313c7b2045SBernd Schmidt } else { 9321da177e4SLinus Torvalds /* overlay a shareable mapping on the backing device or inode 9331da177e4SLinus Torvalds * if possible - used for chardevs, ramfs/tmpfs/shmfs and 9341da177e4SLinus Torvalds * romfs/cramfs */ 935b4caecd4SChristoph Hellwig vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS); 9361da177e4SLinus Torvalds if (flags & MAP_SHARED) 9373c7b2045SBernd Schmidt vm_flags |= VM_SHARED; 9381da177e4SLinus Torvalds } 9391da177e4SLinus Torvalds 9401da177e4SLinus Torvalds /* refuse to let anyone share private mappings with this process if 9411da177e4SLinus Torvalds * it's being traced - otherwise breakpoints set in it may interfere 9421da177e4SLinus Torvalds * with another untraced process 9431da177e4SLinus Torvalds */ 944a288eeccSTejun Heo if ((flags & MAP_PRIVATE) && current->ptrace) 9451da177e4SLinus Torvalds vm_flags &= ~VM_MAYSHARE; 9461da177e4SLinus Torvalds 9471da177e4SLinus Torvalds return vm_flags; 9481da177e4SLinus Torvalds } 9491da177e4SLinus Torvalds 9501da177e4SLinus Torvalds /* 9518feae131SDavid Howells * set up a shared mapping on a file (the driver or filesystem provides and 9528feae131SDavid Howells * pins the storage) 9531da177e4SLinus Torvalds */ 9548feae131SDavid Howells static int do_mmap_shared_file(struct vm_area_struct *vma) 9551da177e4SLinus Torvalds { 9561da177e4SLinus Torvalds int ret; 9571da177e4SLinus Torvalds 958f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 959dd8632a1SPaul Mundt if (ret == 0) { 960dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 961645d83c5SDavid Howells return 0; 962dd8632a1SPaul Mundt } 9631da177e4SLinus Torvalds if (ret != -ENOSYS) 9641da177e4SLinus Torvalds return ret; 9651da177e4SLinus Torvalds 9663fa30460SDavid Howells /* getting -ENOSYS indicates that direct mmap isn't possible (as 9673fa30460SDavid Howells * opposed to tried but failed) so we can only give a suitable error as 9683fa30460SDavid Howells * it's not possible to make a private copy if MAP_SHARED was given */ 9691da177e4SLinus Torvalds return -ENODEV; 9701da177e4SLinus Torvalds } 9711da177e4SLinus Torvalds 9721da177e4SLinus Torvalds /* 9731da177e4SLinus Torvalds * set up a private mapping or an anonymous shared mapping 9741da177e4SLinus Torvalds */ 9758feae131SDavid Howells static int do_mmap_private(struct vm_area_struct *vma, 9768feae131SDavid Howells struct vm_region *region, 977645d83c5SDavid Howells unsigned long len, 978645d83c5SDavid Howells unsigned long capabilities) 9791da177e4SLinus Torvalds { 980dbc8358cSJoonsoo Kim unsigned long total, point; 9811da177e4SLinus Torvalds void *base; 9828feae131SDavid Howells int ret, order; 9831da177e4SLinus Torvalds 9841da177e4SLinus Torvalds /* invoke the file's mapping function so that it can keep track of 9851da177e4SLinus Torvalds * shared mappings on devices or memory 9861da177e4SLinus Torvalds * - VM_MAYSHARE will be set if it may attempt to share 9871da177e4SLinus Torvalds */ 988b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 989f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 990dd8632a1SPaul Mundt if (ret == 0) { 9911da177e4SLinus Torvalds /* shouldn't return success if we're not sharing */ 992dd8632a1SPaul Mundt BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); 993dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 994645d83c5SDavid Howells return 0; 9951da177e4SLinus Torvalds } 996dd8632a1SPaul Mundt if (ret != -ENOSYS) 997dd8632a1SPaul Mundt return ret; 9981da177e4SLinus Torvalds 9991da177e4SLinus Torvalds /* getting an ENOSYS error indicates that direct mmap isn't 10001da177e4SLinus Torvalds * possible (as opposed to tried but failed) so we'll try to 10011da177e4SLinus Torvalds * make a private copy of the data and map that instead */ 10021da177e4SLinus Torvalds } 10031da177e4SLinus Torvalds 10048feae131SDavid Howells 10051da177e4SLinus Torvalds /* allocate some memory to hold the mapping 10061da177e4SLinus Torvalds * - note that this may not return a page-aligned address if the object 10071da177e4SLinus Torvalds * we're allocating is smaller than a page 10081da177e4SLinus Torvalds */ 1009f67d9b15SBob Liu order = get_order(len); 10108feae131SDavid Howells total = 1 << order; 1011f67d9b15SBob Liu point = len >> PAGE_SHIFT; 1012dd8632a1SPaul Mundt 1013dbc8358cSJoonsoo Kim /* we don't want to allocate a power-of-2 sized page set */ 101422cc877bSLeon Romanovsky if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) 1015dbc8358cSJoonsoo Kim total = point; 10168feae131SDavid Howells 1017da616534SJoonsoo Kim base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL); 1018dbc8358cSJoonsoo Kim if (!base) 1019dbc8358cSJoonsoo Kim goto enomem; 10208feae131SDavid Howells 1021dbc8358cSJoonsoo Kim atomic_long_add(total, &mmap_pages_allocated); 1022dbc8358cSJoonsoo Kim 10238feae131SDavid Howells region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; 10248feae131SDavid Howells region->vm_start = (unsigned long) base; 1025f67d9b15SBob Liu region->vm_end = region->vm_start + len; 1026dd8632a1SPaul Mundt region->vm_top = region->vm_start + (total << PAGE_SHIFT); 10278feae131SDavid Howells 10288feae131SDavid Howells vma->vm_start = region->vm_start; 10298feae131SDavid Howells vma->vm_end = region->vm_start + len; 10301da177e4SLinus Torvalds 10311da177e4SLinus Torvalds if (vma->vm_file) { 10321da177e4SLinus Torvalds /* read the contents of a file into the copy */ 10331da177e4SLinus Torvalds loff_t fpos; 10341da177e4SLinus Torvalds 10351da177e4SLinus Torvalds fpos = vma->vm_pgoff; 10361da177e4SLinus Torvalds fpos <<= PAGE_SHIFT; 10371da177e4SLinus Torvalds 1038b4bf802aSChristoph Hellwig ret = kernel_read(vma->vm_file, base, len, &fpos); 10391da177e4SLinus Torvalds if (ret < 0) 10401da177e4SLinus Torvalds goto error_free; 10411da177e4SLinus Torvalds 10421da177e4SLinus Torvalds /* clear the last little bit */ 1043f67d9b15SBob Liu if (ret < len) 1044f67d9b15SBob Liu memset(base + ret, 0, len - ret); 10451da177e4SLinus Torvalds 1046bfd40eafSKirill A. Shutemov } else { 1047bfd40eafSKirill A. Shutemov vma_set_anonymous(vma); 10481da177e4SLinus Torvalds } 10491da177e4SLinus Torvalds 10501da177e4SLinus Torvalds return 0; 10511da177e4SLinus Torvalds 10521da177e4SLinus Torvalds error_free: 10537223bb4aSNamhyung Kim free_page_series(region->vm_start, region->vm_top); 10548feae131SDavid Howells region->vm_start = vma->vm_start = 0; 10558feae131SDavid Howells region->vm_end = vma->vm_end = 0; 1056dd8632a1SPaul Mundt region->vm_top = 0; 10571da177e4SLinus Torvalds return ret; 10581da177e4SLinus Torvalds 10591da177e4SLinus Torvalds enomem: 1060b1de0d13SMitchel Humpherys pr_err("Allocation of length %lu from process %d (%s) failed\n", 106105ae6fa3SGreg Ungerer len, current->pid, current->comm); 10629af744d7SMichal Hocko show_free_areas(0, NULL); 10631da177e4SLinus Torvalds return -ENOMEM; 10641da177e4SLinus Torvalds } 10651da177e4SLinus Torvalds 10661da177e4SLinus Torvalds /* 10671da177e4SLinus Torvalds * handle mapping creation for uClinux 10681da177e4SLinus Torvalds */ 10691fcfd8dbSOleg Nesterov unsigned long do_mmap(struct file *file, 10701da177e4SLinus Torvalds unsigned long addr, 10711da177e4SLinus Torvalds unsigned long len, 10721da177e4SLinus Torvalds unsigned long prot, 10731da177e4SLinus Torvalds unsigned long flags, 1074bebeb3d6SMichel Lespinasse unsigned long pgoff, 1075897ab3e0SMike Rapoport unsigned long *populate, 1076897ab3e0SMike Rapoport struct list_head *uf) 10771da177e4SLinus Torvalds { 10788feae131SDavid Howells struct vm_area_struct *vma; 10798feae131SDavid Howells struct vm_region *region; 10801da177e4SLinus Torvalds struct rb_node *rb; 108145e55300SPeter Collingbourne vm_flags_t vm_flags; 10821fcfd8dbSOleg Nesterov unsigned long capabilities, result; 10831da177e4SLinus Torvalds int ret; 10841da177e4SLinus Torvalds 108541badc15SMichel Lespinasse *populate = 0; 1086bebeb3d6SMichel Lespinasse 10871da177e4SLinus Torvalds /* decide whether we should attempt the mapping, and if so what sort of 10881da177e4SLinus Torvalds * mapping */ 10891da177e4SLinus Torvalds ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, 10901da177e4SLinus Torvalds &capabilities); 109122cc877bSLeon Romanovsky if (ret < 0) 10921da177e4SLinus Torvalds return ret; 10931da177e4SLinus Torvalds 109406aab5a3SDavid Howells /* we ignore the address hint */ 109506aab5a3SDavid Howells addr = 0; 1096f67d9b15SBob Liu len = PAGE_ALIGN(len); 109706aab5a3SDavid Howells 10981da177e4SLinus Torvalds /* we've determined that we can make the mapping, now translate what we 10991da177e4SLinus Torvalds * now know into VMA flags */ 110045e55300SPeter Collingbourne vm_flags = determine_vm_flags(file, prot, flags, capabilities); 11011da177e4SLinus Torvalds 11028feae131SDavid Howells /* we're going to need to record the mapping */ 11038feae131SDavid Howells region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); 11048feae131SDavid Howells if (!region) 11058feae131SDavid Howells goto error_getting_region; 11061da177e4SLinus Torvalds 1107490fc053SLinus Torvalds vma = vm_area_alloc(current->mm); 11088feae131SDavid Howells if (!vma) 11098feae131SDavid Howells goto error_getting_vma; 11101da177e4SLinus Torvalds 11111e2ae599SDavid Howells region->vm_usage = 1; 11128feae131SDavid Howells region->vm_flags = vm_flags; 11138feae131SDavid Howells region->vm_pgoff = pgoff; 11148feae131SDavid Howells 11158feae131SDavid Howells vma->vm_flags = vm_flags; 11168feae131SDavid Howells vma->vm_pgoff = pgoff; 11178feae131SDavid Howells 11188feae131SDavid Howells if (file) { 1119cb0942b8SAl Viro region->vm_file = get_file(file); 1120cb0942b8SAl Viro vma->vm_file = get_file(file); 11218feae131SDavid Howells } 11228feae131SDavid Howells 11238feae131SDavid Howells down_write(&nommu_region_sem); 11248feae131SDavid Howells 11258feae131SDavid Howells /* if we want to share, we need to check for regions created by other 11261da177e4SLinus Torvalds * mmap() calls that overlap with our proposed mapping 11278feae131SDavid Howells * - we can only share with a superset match on most regular files 11281da177e4SLinus Torvalds * - shared mappings on character devices and memory backed files are 11291da177e4SLinus Torvalds * permitted to overlap inexactly as far as we are concerned for in 11301da177e4SLinus Torvalds * these cases, sharing is handled in the driver or filesystem rather 11311da177e4SLinus Torvalds * than here 11321da177e4SLinus Torvalds */ 11331da177e4SLinus Torvalds if (vm_flags & VM_MAYSHARE) { 11348feae131SDavid Howells struct vm_region *pregion; 11358feae131SDavid Howells unsigned long pglen, rpglen, pgend, rpgend, start; 11361da177e4SLinus Torvalds 11378feae131SDavid Howells pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 11388feae131SDavid Howells pgend = pgoff + pglen; 1139165b2392SDavid Howells 11408feae131SDavid Howells for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { 11418feae131SDavid Howells pregion = rb_entry(rb, struct vm_region, vm_rb); 11421da177e4SLinus Torvalds 11438feae131SDavid Howells if (!(pregion->vm_flags & VM_MAYSHARE)) 11441da177e4SLinus Torvalds continue; 11451da177e4SLinus Torvalds 11461da177e4SLinus Torvalds /* search for overlapping mappings on the same file */ 1147496ad9aaSAl Viro if (file_inode(pregion->vm_file) != 1148496ad9aaSAl Viro file_inode(file)) 11491da177e4SLinus Torvalds continue; 11501da177e4SLinus Torvalds 11518feae131SDavid Howells if (pregion->vm_pgoff >= pgend) 11521da177e4SLinus Torvalds continue; 11531da177e4SLinus Torvalds 11548feae131SDavid Howells rpglen = pregion->vm_end - pregion->vm_start; 11558feae131SDavid Howells rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; 11568feae131SDavid Howells rpgend = pregion->vm_pgoff + rpglen; 11578feae131SDavid Howells if (pgoff >= rpgend) 11581da177e4SLinus Torvalds continue; 11591da177e4SLinus Torvalds 11608feae131SDavid Howells /* handle inexactly overlapping matches between 11618feae131SDavid Howells * mappings */ 11628feae131SDavid Howells if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && 11638feae131SDavid Howells !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { 11648feae131SDavid Howells /* new mapping is not a subset of the region */ 1165b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 11661da177e4SLinus Torvalds goto sharing_violation; 11671da177e4SLinus Torvalds continue; 11681da177e4SLinus Torvalds } 11691da177e4SLinus Torvalds 11708feae131SDavid Howells /* we've found a region we can share */ 11711e2ae599SDavid Howells pregion->vm_usage++; 11728feae131SDavid Howells vma->vm_region = pregion; 11738feae131SDavid Howells start = pregion->vm_start; 11748feae131SDavid Howells start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; 11758feae131SDavid Howells vma->vm_start = start; 11768feae131SDavid Howells vma->vm_end = start + len; 11771da177e4SLinus Torvalds 117822cc877bSLeon Romanovsky if (pregion->vm_flags & VM_MAPPED_COPY) 11798feae131SDavid Howells vma->vm_flags |= VM_MAPPED_COPY; 118022cc877bSLeon Romanovsky else { 11818feae131SDavid Howells ret = do_mmap_shared_file(vma); 11828feae131SDavid Howells if (ret < 0) { 11838feae131SDavid Howells vma->vm_region = NULL; 11848feae131SDavid Howells vma->vm_start = 0; 11858feae131SDavid Howells vma->vm_end = 0; 11861e2ae599SDavid Howells pregion->vm_usage--; 11878feae131SDavid Howells pregion = NULL; 11888feae131SDavid Howells goto error_just_free; 11891da177e4SLinus Torvalds } 11908feae131SDavid Howells } 11918feae131SDavid Howells fput(region->vm_file); 11928feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 11938feae131SDavid Howells region = pregion; 11948feae131SDavid Howells result = start; 11958feae131SDavid Howells goto share; 11968feae131SDavid Howells } 11971da177e4SLinus Torvalds 11981da177e4SLinus Torvalds /* obtain the address at which to make a shared mapping 11991da177e4SLinus Torvalds * - this is the hook for quasi-memory character devices to 12001da177e4SLinus Torvalds * tell us the location of a shared mapping 12011da177e4SLinus Torvalds */ 1202b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 12031da177e4SLinus Torvalds addr = file->f_op->get_unmapped_area(file, addr, len, 12041da177e4SLinus Torvalds pgoff, flags); 1205bb005a59SNamhyung Kim if (IS_ERR_VALUE(addr)) { 12061da177e4SLinus Torvalds ret = addr; 1207bb005a59SNamhyung Kim if (ret != -ENOSYS) 12088feae131SDavid Howells goto error_just_free; 12091da177e4SLinus Torvalds 12101da177e4SLinus Torvalds /* the driver refused to tell us where to site 12111da177e4SLinus Torvalds * the mapping so we'll have to attempt to copy 12121da177e4SLinus Torvalds * it */ 1213bb005a59SNamhyung Kim ret = -ENODEV; 1214b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 12158feae131SDavid Howells goto error_just_free; 12161da177e4SLinus Torvalds 1217b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 12188feae131SDavid Howells } else { 12198feae131SDavid Howells vma->vm_start = region->vm_start = addr; 12208feae131SDavid Howells vma->vm_end = region->vm_end = addr + len; 12211da177e4SLinus Torvalds } 12221da177e4SLinus Torvalds } 12231da177e4SLinus Torvalds } 12241da177e4SLinus Torvalds 12258feae131SDavid Howells vma->vm_region = region; 12261da177e4SLinus Torvalds 1227645d83c5SDavid Howells /* set up the mapping 1228b4caecd4SChristoph Hellwig * - the region is filled in if NOMMU_MAP_DIRECT is still set 1229645d83c5SDavid Howells */ 12301da177e4SLinus Torvalds if (file && vma->vm_flags & VM_SHARED) 12318feae131SDavid Howells ret = do_mmap_shared_file(vma); 12321da177e4SLinus Torvalds else 1233645d83c5SDavid Howells ret = do_mmap_private(vma, region, len, capabilities); 12341da177e4SLinus Torvalds if (ret < 0) 1235645d83c5SDavid Howells goto error_just_free; 1236645d83c5SDavid Howells add_nommu_region(region); 12378feae131SDavid Howells 1238ea637639SJie Zhang /* clear anonymous mappings that don't ask for uninitialized data */ 12390bf5f949SChristoph Hellwig if (!vma->vm_file && 12400bf5f949SChristoph Hellwig (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) || 12410bf5f949SChristoph Hellwig !(flags & MAP_UNINITIALIZED))) 1242ea637639SJie Zhang memset((void *)region->vm_start, 0, 1243ea637639SJie Zhang region->vm_end - region->vm_start); 1244ea637639SJie Zhang 12451da177e4SLinus Torvalds /* okay... we have a mapping; now we have to register it */ 12468feae131SDavid Howells result = vma->vm_start; 12471da177e4SLinus Torvalds 12481da177e4SLinus Torvalds current->mm->total_vm += len >> PAGE_SHIFT; 12491da177e4SLinus Torvalds 12508feae131SDavid Howells share: 12518feae131SDavid Howells add_vma_to_mm(current->mm, vma); 12521da177e4SLinus Torvalds 1253cfe79c00SMike Frysinger /* we flush the region from the icache only when the first executable 1254cfe79c00SMike Frysinger * mapping of it is made */ 1255cfe79c00SMike Frysinger if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { 1256a75a2df6SChristoph Hellwig flush_icache_user_range(region->vm_start, region->vm_end); 1257cfe79c00SMike Frysinger region->vm_icache_flushed = true; 1258cfe79c00SMike Frysinger } 12591da177e4SLinus Torvalds 1260cfe79c00SMike Frysinger up_write(&nommu_region_sem); 12611da177e4SLinus Torvalds 12628feae131SDavid Howells return result; 12631da177e4SLinus Torvalds 12648feae131SDavid Howells error_just_free: 12658feae131SDavid Howells up_write(&nommu_region_sem); 12668feae131SDavid Howells error: 126789a86402SDavid Howells if (region->vm_file) 12688feae131SDavid Howells fput(region->vm_file); 12698feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 127089a86402SDavid Howells if (vma->vm_file) 12718feae131SDavid Howells fput(vma->vm_file); 12723928d4f5SLinus Torvalds vm_area_free(vma); 12731da177e4SLinus Torvalds return ret; 12741da177e4SLinus Torvalds 12751da177e4SLinus Torvalds sharing_violation: 12768feae131SDavid Howells up_write(&nommu_region_sem); 127722cc877bSLeon Romanovsky pr_warn("Attempt to share mismatched mappings\n"); 12788feae131SDavid Howells ret = -EINVAL; 12798feae131SDavid Howells goto error; 12801da177e4SLinus Torvalds 12811da177e4SLinus Torvalds error_getting_vma: 12828feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 128322cc877bSLeon Romanovsky pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n", 12841da177e4SLinus Torvalds len, current->pid); 12859af744d7SMichal Hocko show_free_areas(0, NULL); 12861da177e4SLinus Torvalds return -ENOMEM; 12871da177e4SLinus Torvalds 12888feae131SDavid Howells error_getting_region: 128922cc877bSLeon Romanovsky pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n", 12901da177e4SLinus Torvalds len, current->pid); 12919af744d7SMichal Hocko show_free_areas(0, NULL); 12921da177e4SLinus Torvalds return -ENOMEM; 12931da177e4SLinus Torvalds } 12946be5ceb0SLinus Torvalds 1295a90f590aSDominik Brodowski unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, 1296a90f590aSDominik Brodowski unsigned long prot, unsigned long flags, 1297a90f590aSDominik Brodowski unsigned long fd, unsigned long pgoff) 129866f0dc48SHugh Dickins { 129966f0dc48SHugh Dickins struct file *file = NULL; 130066f0dc48SHugh Dickins unsigned long retval = -EBADF; 130166f0dc48SHugh Dickins 1302120a795dSAl Viro audit_mmap_fd(fd, flags); 130366f0dc48SHugh Dickins if (!(flags & MAP_ANONYMOUS)) { 130466f0dc48SHugh Dickins file = fget(fd); 130566f0dc48SHugh Dickins if (!file) 130666f0dc48SHugh Dickins goto out; 130766f0dc48SHugh Dickins } 130866f0dc48SHugh Dickins 130966f0dc48SHugh Dickins flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); 131066f0dc48SHugh Dickins 1311ad1ed293SGreg Ungerer retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); 131266f0dc48SHugh Dickins 131366f0dc48SHugh Dickins if (file) 131466f0dc48SHugh Dickins fput(file); 131566f0dc48SHugh Dickins out: 131666f0dc48SHugh Dickins return retval; 131766f0dc48SHugh Dickins } 131866f0dc48SHugh Dickins 1319a90f590aSDominik Brodowski SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 1320a90f590aSDominik Brodowski unsigned long, prot, unsigned long, flags, 1321a90f590aSDominik Brodowski unsigned long, fd, unsigned long, pgoff) 1322a90f590aSDominik Brodowski { 1323a90f590aSDominik Brodowski return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); 1324a90f590aSDominik Brodowski } 1325a90f590aSDominik Brodowski 1326a4679373SChristoph Hellwig #ifdef __ARCH_WANT_SYS_OLD_MMAP 1327a4679373SChristoph Hellwig struct mmap_arg_struct { 1328a4679373SChristoph Hellwig unsigned long addr; 1329a4679373SChristoph Hellwig unsigned long len; 1330a4679373SChristoph Hellwig unsigned long prot; 1331a4679373SChristoph Hellwig unsigned long flags; 1332a4679373SChristoph Hellwig unsigned long fd; 1333a4679373SChristoph Hellwig unsigned long offset; 1334a4679373SChristoph Hellwig }; 1335a4679373SChristoph Hellwig 1336a4679373SChristoph Hellwig SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) 1337a4679373SChristoph Hellwig { 1338a4679373SChristoph Hellwig struct mmap_arg_struct a; 1339a4679373SChristoph Hellwig 1340a4679373SChristoph Hellwig if (copy_from_user(&a, arg, sizeof(a))) 1341a4679373SChristoph Hellwig return -EFAULT; 13421824cb75SAlexander Kuleshov if (offset_in_page(a.offset)) 1343a4679373SChristoph Hellwig return -EINVAL; 1344a4679373SChristoph Hellwig 1345a90f590aSDominik Brodowski return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, 1346a4679373SChristoph Hellwig a.offset >> PAGE_SHIFT); 1347a4679373SChristoph Hellwig } 1348a4679373SChristoph Hellwig #endif /* __ARCH_WANT_SYS_OLD_MMAP */ 1349a4679373SChristoph Hellwig 13501da177e4SLinus Torvalds /* 13518feae131SDavid Howells * split a vma into two pieces at address 'addr', a new vma is allocated either 13528feae131SDavid Howells * for the first part or the tail. 13531da177e4SLinus Torvalds */ 13548feae131SDavid Howells int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 13558feae131SDavid Howells unsigned long addr, int new_below) 13561da177e4SLinus Torvalds { 13578feae131SDavid Howells struct vm_area_struct *new; 13588feae131SDavid Howells struct vm_region *region; 13598feae131SDavid Howells unsigned long npages; 13601da177e4SLinus Torvalds 1361779c1023SDavid Howells /* we're only permitted to split anonymous regions (these should have 1362779c1023SDavid Howells * only a single usage on the region) */ 1363779c1023SDavid Howells if (vma->vm_file) 13648feae131SDavid Howells return -ENOMEM; 13651da177e4SLinus Torvalds 13668feae131SDavid Howells if (mm->map_count >= sysctl_max_map_count) 13678feae131SDavid Howells return -ENOMEM; 13681da177e4SLinus Torvalds 13698feae131SDavid Howells region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); 13708feae131SDavid Howells if (!region) 13718feae131SDavid Howells return -ENOMEM; 13728feae131SDavid Howells 13733928d4f5SLinus Torvalds new = vm_area_dup(vma); 13748feae131SDavid Howells if (!new) { 13758feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 13768feae131SDavid Howells return -ENOMEM; 13771da177e4SLinus Torvalds } 13781da177e4SLinus Torvalds 13798feae131SDavid Howells /* most fields are the same, copy all, and then fixup */ 13808feae131SDavid Howells *region = *vma->vm_region; 13818feae131SDavid Howells new->vm_region = region; 13828feae131SDavid Howells 13838feae131SDavid Howells npages = (addr - vma->vm_start) >> PAGE_SHIFT; 13848feae131SDavid Howells 13858feae131SDavid Howells if (new_below) { 1386dd8632a1SPaul Mundt region->vm_top = region->vm_end = new->vm_end = addr; 13878feae131SDavid Howells } else { 13888feae131SDavid Howells region->vm_start = new->vm_start = addr; 13898feae131SDavid Howells region->vm_pgoff = new->vm_pgoff += npages; 13901da177e4SLinus Torvalds } 13918feae131SDavid Howells 13928feae131SDavid Howells if (new->vm_ops && new->vm_ops->open) 13938feae131SDavid Howells new->vm_ops->open(new); 13948feae131SDavid Howells 13958feae131SDavid Howells delete_vma_from_mm(vma); 13968feae131SDavid Howells down_write(&nommu_region_sem); 13978feae131SDavid Howells delete_nommu_region(vma->vm_region); 13988feae131SDavid Howells if (new_below) { 13998feae131SDavid Howells vma->vm_region->vm_start = vma->vm_start = addr; 14008feae131SDavid Howells vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; 14018feae131SDavid Howells } else { 14028feae131SDavid Howells vma->vm_region->vm_end = vma->vm_end = addr; 1403dd8632a1SPaul Mundt vma->vm_region->vm_top = addr; 14048feae131SDavid Howells } 14058feae131SDavid Howells add_nommu_region(vma->vm_region); 14068feae131SDavid Howells add_nommu_region(new->vm_region); 14078feae131SDavid Howells up_write(&nommu_region_sem); 14088feae131SDavid Howells add_vma_to_mm(mm, vma); 14098feae131SDavid Howells add_vma_to_mm(mm, new); 14108feae131SDavid Howells return 0; 14118feae131SDavid Howells } 14128feae131SDavid Howells 14138feae131SDavid Howells /* 14148feae131SDavid Howells * shrink a VMA by removing the specified chunk from either the beginning or 14158feae131SDavid Howells * the end 14168feae131SDavid Howells */ 14178feae131SDavid Howells static int shrink_vma(struct mm_struct *mm, 14188feae131SDavid Howells struct vm_area_struct *vma, 14198feae131SDavid Howells unsigned long from, unsigned long to) 14208feae131SDavid Howells { 14218feae131SDavid Howells struct vm_region *region; 14228feae131SDavid Howells 14238feae131SDavid Howells /* adjust the VMA's pointers, which may reposition it in the MM's tree 14248feae131SDavid Howells * and list */ 14258feae131SDavid Howells delete_vma_from_mm(vma); 14268feae131SDavid Howells if (from > vma->vm_start) 14278feae131SDavid Howells vma->vm_end = from; 14288feae131SDavid Howells else 14298feae131SDavid Howells vma->vm_start = to; 14308feae131SDavid Howells add_vma_to_mm(mm, vma); 14318feae131SDavid Howells 14328feae131SDavid Howells /* cut the backing region down to size */ 14338feae131SDavid Howells region = vma->vm_region; 14341e2ae599SDavid Howells BUG_ON(region->vm_usage != 1); 14358feae131SDavid Howells 14368feae131SDavid Howells down_write(&nommu_region_sem); 14378feae131SDavid Howells delete_nommu_region(region); 1438dd8632a1SPaul Mundt if (from > region->vm_start) { 1439dd8632a1SPaul Mundt to = region->vm_top; 1440dd8632a1SPaul Mundt region->vm_top = region->vm_end = from; 1441dd8632a1SPaul Mundt } else { 14428feae131SDavid Howells region->vm_start = to; 1443dd8632a1SPaul Mundt } 14448feae131SDavid Howells add_nommu_region(region); 14458feae131SDavid Howells up_write(&nommu_region_sem); 14468feae131SDavid Howells 14478feae131SDavid Howells free_page_series(from, to); 14488feae131SDavid Howells return 0; 14491da177e4SLinus Torvalds } 14501da177e4SLinus Torvalds 14513034097aSDavid Howells /* 14523034097aSDavid Howells * release a mapping 14538feae131SDavid Howells * - under NOMMU conditions the chunk to be unmapped must be backed by a single 14548feae131SDavid Howells * VMA, though it need not cover the whole VMA 14553034097aSDavid Howells */ 1456897ab3e0SMike Rapoport int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) 14571da177e4SLinus Torvalds { 14588feae131SDavid Howells struct vm_area_struct *vma; 1459f67d9b15SBob Liu unsigned long end; 14608feae131SDavid Howells int ret; 14611da177e4SLinus Torvalds 1462f67d9b15SBob Liu len = PAGE_ALIGN(len); 14638feae131SDavid Howells if (len == 0) 14641da177e4SLinus Torvalds return -EINVAL; 14651da177e4SLinus Torvalds 1466f67d9b15SBob Liu end = start + len; 1467f67d9b15SBob Liu 14688feae131SDavid Howells /* find the first potentially overlapping VMA */ 14698feae131SDavid Howells vma = find_vma(mm, start); 14708feae131SDavid Howells if (!vma) { 1471ac714904SChoi Gi-yong static int limit; 147233e5d769SDavid Howells if (limit < 5) { 147322cc877bSLeon Romanovsky pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n", 147433e5d769SDavid Howells current->pid, current->comm, 147533e5d769SDavid Howells start, start + len - 1); 147633e5d769SDavid Howells limit++; 147733e5d769SDavid Howells } 14788feae131SDavid Howells return -EINVAL; 14798feae131SDavid Howells } 14801da177e4SLinus Torvalds 14818feae131SDavid Howells /* we're allowed to split an anonymous VMA but not a file-backed one */ 14828feae131SDavid Howells if (vma->vm_file) { 14838feae131SDavid Howells do { 148422cc877bSLeon Romanovsky if (start > vma->vm_start) 14858feae131SDavid Howells return -EINVAL; 14868feae131SDavid Howells if (end == vma->vm_end) 14878feae131SDavid Howells goto erase_whole_vma; 1488d75a310cSNamhyung Kim vma = vma->vm_next; 1489d75a310cSNamhyung Kim } while (vma); 14908feae131SDavid Howells return -EINVAL; 14918feae131SDavid Howells } else { 14928feae131SDavid Howells /* the chunk must be a subset of the VMA found */ 14938feae131SDavid Howells if (start == vma->vm_start && end == vma->vm_end) 14948feae131SDavid Howells goto erase_whole_vma; 149522cc877bSLeon Romanovsky if (start < vma->vm_start || end > vma->vm_end) 14968feae131SDavid Howells return -EINVAL; 14971824cb75SAlexander Kuleshov if (offset_in_page(start)) 14988feae131SDavid Howells return -EINVAL; 14991824cb75SAlexander Kuleshov if (end != vma->vm_end && offset_in_page(end)) 15008feae131SDavid Howells return -EINVAL; 15018feae131SDavid Howells if (start != vma->vm_start && end != vma->vm_end) { 15028feae131SDavid Howells ret = split_vma(mm, vma, start, 1); 150322cc877bSLeon Romanovsky if (ret < 0) 15048feae131SDavid Howells return ret; 15058feae131SDavid Howells } 15068feae131SDavid Howells return shrink_vma(mm, vma, start, end); 15078feae131SDavid Howells } 15081da177e4SLinus Torvalds 15098feae131SDavid Howells erase_whole_vma: 15108feae131SDavid Howells delete_vma_from_mm(vma); 15118feae131SDavid Howells delete_vma(mm, vma); 15121da177e4SLinus Torvalds return 0; 15131da177e4SLinus Torvalds } 1514b5073173SPaul Mundt EXPORT_SYMBOL(do_munmap); 15151da177e4SLinus Torvalds 1516bfce281cSAl Viro int vm_munmap(unsigned long addr, size_t len) 15173034097aSDavid Howells { 1518bfce281cSAl Viro struct mm_struct *mm = current->mm; 15193034097aSDavid Howells int ret; 15203034097aSDavid Howells 1521d8ed45c5SMichel Lespinasse mmap_write_lock(mm); 1522897ab3e0SMike Rapoport ret = do_munmap(mm, addr, len, NULL); 1523d8ed45c5SMichel Lespinasse mmap_write_unlock(mm); 15243034097aSDavid Howells return ret; 15253034097aSDavid Howells } 1526a46ef99dSLinus Torvalds EXPORT_SYMBOL(vm_munmap); 1527a46ef99dSLinus Torvalds 1528a46ef99dSLinus Torvalds SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) 1529a46ef99dSLinus Torvalds { 1530bfce281cSAl Viro return vm_munmap(addr, len); 1531a46ef99dSLinus Torvalds } 15323034097aSDavid Howells 15333034097aSDavid Howells /* 15348feae131SDavid Howells * release all the mappings made in a process's VM space 15353034097aSDavid Howells */ 15361da177e4SLinus Torvalds void exit_mmap(struct mm_struct *mm) 15371da177e4SLinus Torvalds { 15388feae131SDavid Howells struct vm_area_struct *vma; 15391da177e4SLinus Torvalds 15408feae131SDavid Howells if (!mm) 15418feae131SDavid Howells return; 15428feae131SDavid Howells 15431da177e4SLinus Torvalds mm->total_vm = 0; 15441da177e4SLinus Torvalds 15458feae131SDavid Howells while ((vma = mm->mmap)) { 15468feae131SDavid Howells mm->mmap = vma->vm_next; 15478feae131SDavid Howells delete_vma_from_mm(vma); 15488feae131SDavid Howells delete_vma(mm, vma); 154904c34961SSteven J. Magnani cond_resched(); 15501da177e4SLinus Torvalds } 15511da177e4SLinus Torvalds } 15521da177e4SLinus Torvalds 15535d22fc25SLinus Torvalds int vm_brk(unsigned long addr, unsigned long len) 15541da177e4SLinus Torvalds { 15551da177e4SLinus Torvalds return -ENOMEM; 15561da177e4SLinus Torvalds } 15571da177e4SLinus Torvalds 15581da177e4SLinus Torvalds /* 15596fa5f80bSDavid Howells * expand (or shrink) an existing mapping, potentially moving it at the same 15606fa5f80bSDavid Howells * time (controlled by the MREMAP_MAYMOVE flag and available VM space) 15611da177e4SLinus Torvalds * 15626fa5f80bSDavid Howells * under NOMMU conditions, we only permit changing a mapping's size, and only 15638feae131SDavid Howells * as long as it stays within the region allocated by do_mmap_private() and the 15648feae131SDavid Howells * block is not shareable 15651da177e4SLinus Torvalds * 15666fa5f80bSDavid Howells * MREMAP_FIXED is not supported under NOMMU conditions 15671da177e4SLinus Torvalds */ 15684b377babSAl Viro static unsigned long do_mremap(unsigned long addr, 15691da177e4SLinus Torvalds unsigned long old_len, unsigned long new_len, 15701da177e4SLinus Torvalds unsigned long flags, unsigned long new_addr) 15711da177e4SLinus Torvalds { 15726fa5f80bSDavid Howells struct vm_area_struct *vma; 15731da177e4SLinus Torvalds 15741da177e4SLinus Torvalds /* insanity checks first */ 1575f67d9b15SBob Liu old_len = PAGE_ALIGN(old_len); 1576f67d9b15SBob Liu new_len = PAGE_ALIGN(new_len); 15778feae131SDavid Howells if (old_len == 0 || new_len == 0) 15781da177e4SLinus Torvalds return (unsigned long) -EINVAL; 15791da177e4SLinus Torvalds 15801824cb75SAlexander Kuleshov if (offset_in_page(addr)) 15818feae131SDavid Howells return -EINVAL; 15828feae131SDavid Howells 15831da177e4SLinus Torvalds if (flags & MREMAP_FIXED && new_addr != addr) 15841da177e4SLinus Torvalds return (unsigned long) -EINVAL; 15851da177e4SLinus Torvalds 15868feae131SDavid Howells vma = find_vma_exact(current->mm, addr, old_len); 15876fa5f80bSDavid Howells if (!vma) 15881da177e4SLinus Torvalds return (unsigned long) -EINVAL; 15891da177e4SLinus Torvalds 15906fa5f80bSDavid Howells if (vma->vm_end != vma->vm_start + old_len) 15911da177e4SLinus Torvalds return (unsigned long) -EFAULT; 15921da177e4SLinus Torvalds 15936fa5f80bSDavid Howells if (vma->vm_flags & VM_MAYSHARE) 15941da177e4SLinus Torvalds return (unsigned long) -EPERM; 15951da177e4SLinus Torvalds 15968feae131SDavid Howells if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) 15971da177e4SLinus Torvalds return (unsigned long) -ENOMEM; 15981da177e4SLinus Torvalds 15991da177e4SLinus Torvalds /* all checks complete - do it */ 16006fa5f80bSDavid Howells vma->vm_end = vma->vm_start + new_len; 16016fa5f80bSDavid Howells return vma->vm_start; 16026fa5f80bSDavid Howells } 16036fa5f80bSDavid Howells 16046a6160a7SHeiko Carstens SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 16056a6160a7SHeiko Carstens unsigned long, new_len, unsigned long, flags, 16066a6160a7SHeiko Carstens unsigned long, new_addr) 16076fa5f80bSDavid Howells { 16086fa5f80bSDavid Howells unsigned long ret; 16096fa5f80bSDavid Howells 1610d8ed45c5SMichel Lespinasse mmap_write_lock(current->mm); 16116fa5f80bSDavid Howells ret = do_mremap(addr, old_len, new_len, flags, new_addr); 1612d8ed45c5SMichel Lespinasse mmap_write_unlock(current->mm); 16136fa5f80bSDavid Howells return ret; 16141da177e4SLinus Torvalds } 16151da177e4SLinus Torvalds 1616df06b37fSKeith Busch struct page *follow_page(struct vm_area_struct *vma, unsigned long address, 1617df06b37fSKeith Busch unsigned int foll_flags) 16181da177e4SLinus Torvalds { 16191da177e4SLinus Torvalds return NULL; 16201da177e4SLinus Torvalds } 16211da177e4SLinus Torvalds 16228f3b1327SBob Liu int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 16238f3b1327SBob Liu unsigned long pfn, unsigned long size, pgprot_t prot) 16241da177e4SLinus Torvalds { 16258f3b1327SBob Liu if (addr != (pfn << PAGE_SHIFT)) 16268f3b1327SBob Liu return -EINVAL; 16278f3b1327SBob Liu 1628314e51b9SKonstantin Khlebnikov vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 162966aa2b4bSGreg Ungerer return 0; 16301da177e4SLinus Torvalds } 163122c4af40SLuke Yang EXPORT_SYMBOL(remap_pfn_range); 16321da177e4SLinus Torvalds 16333c0b9de6SLinus Torvalds int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) 16343c0b9de6SLinus Torvalds { 16353c0b9de6SLinus Torvalds unsigned long pfn = start >> PAGE_SHIFT; 16363c0b9de6SLinus Torvalds unsigned long vm_len = vma->vm_end - vma->vm_start; 16373c0b9de6SLinus Torvalds 16383c0b9de6SLinus Torvalds pfn += vma->vm_pgoff; 16393c0b9de6SLinus Torvalds return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); 16403c0b9de6SLinus Torvalds } 16413c0b9de6SLinus Torvalds EXPORT_SYMBOL(vm_iomap_memory); 16423c0b9de6SLinus Torvalds 1643f905bc44SPaul Mundt int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 1644f905bc44SPaul Mundt unsigned long pgoff) 1645f905bc44SPaul Mundt { 1646f905bc44SPaul Mundt unsigned int size = vma->vm_end - vma->vm_start; 1647f905bc44SPaul Mundt 1648f905bc44SPaul Mundt if (!(vma->vm_flags & VM_USERMAP)) 1649f905bc44SPaul Mundt return -EINVAL; 1650f905bc44SPaul Mundt 1651f905bc44SPaul Mundt vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); 1652f905bc44SPaul Mundt vma->vm_end = vma->vm_start + size; 1653f905bc44SPaul Mundt 1654f905bc44SPaul Mundt return 0; 1655f905bc44SPaul Mundt } 1656f905bc44SPaul Mundt EXPORT_SYMBOL(remap_vmalloc_range); 1657f905bc44SPaul Mundt 16581da177e4SLinus Torvalds unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, 16591da177e4SLinus Torvalds unsigned long len, unsigned long pgoff, unsigned long flags) 16601da177e4SLinus Torvalds { 16611da177e4SLinus Torvalds return -ENOMEM; 16621da177e4SLinus Torvalds } 16631da177e4SLinus Torvalds 16642bcd6454SSouptick Joarder vm_fault_t filemap_fault(struct vm_fault *vmf) 1665b0e15190SDavid Howells { 1666b0e15190SDavid Howells BUG(); 1667d0217ac0SNick Piggin return 0; 1668b0e15190SDavid Howells } 1669b5073173SPaul Mundt EXPORT_SYMBOL(filemap_fault); 16700ec76a11SDavid Howells 167182b0f8c3SJan Kara void filemap_map_pages(struct vm_fault *vmf, 1672bae473a4SKirill A. Shutemov pgoff_t start_pgoff, pgoff_t end_pgoff) 1673f1820361SKirill A. Shutemov { 1674f1820361SKirill A. Shutemov BUG(); 1675f1820361SKirill A. Shutemov } 1676f1820361SKirill A. Shutemov EXPORT_SYMBOL(filemap_map_pages); 1677f1820361SKirill A. Shutemov 1678*d3f5ffcaSJohn Hubbard int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf, 1679*d3f5ffcaSJohn Hubbard int len, unsigned int gup_flags) 16800ec76a11SDavid Howells { 16810ec76a11SDavid Howells struct vm_area_struct *vma; 1682442486ecSLorenzo Stoakes int write = gup_flags & FOLL_WRITE; 16830ec76a11SDavid Howells 1684d8ed45c5SMichel Lespinasse if (mmap_read_lock_killable(mm)) 16851e426fe2SKonstantin Khlebnikov return 0; 16860ec76a11SDavid Howells 16870ec76a11SDavid Howells /* the access must start within one of the target process's mappings */ 16880159b141SDavid Howells vma = find_vma(mm, addr); 16890159b141SDavid Howells if (vma) { 16900ec76a11SDavid Howells /* don't overrun this mapping */ 16910ec76a11SDavid Howells if (addr + len >= vma->vm_end) 16920ec76a11SDavid Howells len = vma->vm_end - addr; 16930ec76a11SDavid Howells 16940ec76a11SDavid Howells /* only read or write mappings where it is permitted */ 1695d00c7b99SDavid Howells if (write && vma->vm_flags & VM_MAYWRITE) 16967959722bSJie Zhang copy_to_user_page(vma, NULL, addr, 16977959722bSJie Zhang (void *) addr, buf, len); 1698d00c7b99SDavid Howells else if (!write && vma->vm_flags & VM_MAYREAD) 16997959722bSJie Zhang copy_from_user_page(vma, NULL, addr, 17007959722bSJie Zhang buf, (void *) addr, len); 17010ec76a11SDavid Howells else 17020ec76a11SDavid Howells len = 0; 17030ec76a11SDavid Howells } else { 17040ec76a11SDavid Howells len = 0; 17050ec76a11SDavid Howells } 17060ec76a11SDavid Howells 1707d8ed45c5SMichel Lespinasse mmap_read_unlock(mm); 1708f55f199bSMike Frysinger 1709f55f199bSMike Frysinger return len; 1710f55f199bSMike Frysinger } 1711f55f199bSMike Frysinger 1712f55f199bSMike Frysinger /** 1713b7701a5fSMike Rapoport * access_remote_vm - access another process' address space 1714f55f199bSMike Frysinger * @mm: the mm_struct of the target address space 1715f55f199bSMike Frysinger * @addr: start address to access 1716f55f199bSMike Frysinger * @buf: source or destination buffer 1717f55f199bSMike Frysinger * @len: number of bytes to transfer 17186347e8d5SLorenzo Stoakes * @gup_flags: flags modifying lookup behaviour 1719f55f199bSMike Frysinger * 1720f55f199bSMike Frysinger * The caller must hold a reference on @mm. 1721f55f199bSMike Frysinger */ 1722f55f199bSMike Frysinger int access_remote_vm(struct mm_struct *mm, unsigned long addr, 17236347e8d5SLorenzo Stoakes void *buf, int len, unsigned int gup_flags) 1724f55f199bSMike Frysinger { 1725*d3f5ffcaSJohn Hubbard return __access_remote_vm(mm, addr, buf, len, gup_flags); 1726f55f199bSMike Frysinger } 1727f55f199bSMike Frysinger 1728f55f199bSMike Frysinger /* 1729f55f199bSMike Frysinger * Access another process' address space. 1730f55f199bSMike Frysinger * - source/target buffer must be kernel space 1731f55f199bSMike Frysinger */ 1732f307ab6dSLorenzo Stoakes int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, 1733f307ab6dSLorenzo Stoakes unsigned int gup_flags) 1734f55f199bSMike Frysinger { 1735f55f199bSMike Frysinger struct mm_struct *mm; 1736f55f199bSMike Frysinger 1737f55f199bSMike Frysinger if (addr + len < addr) 1738f55f199bSMike Frysinger return 0; 1739f55f199bSMike Frysinger 1740f55f199bSMike Frysinger mm = get_task_mm(tsk); 1741f55f199bSMike Frysinger if (!mm) 1742f55f199bSMike Frysinger return 0; 1743f55f199bSMike Frysinger 1744*d3f5ffcaSJohn Hubbard len = __access_remote_vm(mm, addr, buf, len, gup_flags); 1745f55f199bSMike Frysinger 17460ec76a11SDavid Howells mmput(mm); 17470ec76a11SDavid Howells return len; 17480ec76a11SDavid Howells } 1749fcd35857SCatalin Marinas EXPORT_SYMBOL_GPL(access_process_vm); 17507e660872SDavid Howells 17517e660872SDavid Howells /** 17527e660872SDavid Howells * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode 17537e660872SDavid Howells * @inode: The inode to check 17547e660872SDavid Howells * @size: The current filesize of the inode 17557e660872SDavid Howells * @newsize: The proposed filesize of the inode 17567e660872SDavid Howells * 17577e660872SDavid Howells * Check the shared mappings on an inode on behalf of a shrinking truncate to 1758c08b342cSRandy Dunlap * make sure that any outstanding VMAs aren't broken and then shrink the 1759c08b342cSRandy Dunlap * vm_regions that extend beyond so that do_mmap() doesn't 17607e660872SDavid Howells * automatically grant mappings that are too large. 17617e660872SDavid Howells */ 17627e660872SDavid Howells int nommu_shrink_inode_mappings(struct inode *inode, size_t size, 17637e660872SDavid Howells size_t newsize) 17647e660872SDavid Howells { 17657e660872SDavid Howells struct vm_area_struct *vma; 17667e660872SDavid Howells struct vm_region *region; 17677e660872SDavid Howells pgoff_t low, high; 17687e660872SDavid Howells size_t r_size, r_top; 17697e660872SDavid Howells 17707e660872SDavid Howells low = newsize >> PAGE_SHIFT; 17717e660872SDavid Howells high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 17727e660872SDavid Howells 17737e660872SDavid Howells down_write(&nommu_region_sem); 17741acf2e04SDavidlohr Bueso i_mmap_lock_read(inode->i_mapping); 17757e660872SDavid Howells 17767e660872SDavid Howells /* search for VMAs that fall within the dead zone */ 17776b2dbba8SMichel Lespinasse vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) { 17787e660872SDavid Howells /* found one - only interested if it's shared out of the page 17797e660872SDavid Howells * cache */ 17807e660872SDavid Howells if (vma->vm_flags & VM_SHARED) { 17811acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 17827e660872SDavid Howells up_write(&nommu_region_sem); 17837e660872SDavid Howells return -ETXTBSY; /* not quite true, but near enough */ 17847e660872SDavid Howells } 17857e660872SDavid Howells } 17867e660872SDavid Howells 17877e660872SDavid Howells /* reduce any regions that overlap the dead zone - if in existence, 17887e660872SDavid Howells * these will be pointed to by VMAs that don't overlap the dead zone 17897e660872SDavid Howells * 17907e660872SDavid Howells * we don't check for any regions that start beyond the EOF as there 17917e660872SDavid Howells * shouldn't be any 17927e660872SDavid Howells */ 17931acf2e04SDavidlohr Bueso vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 0, ULONG_MAX) { 17947e660872SDavid Howells if (!(vma->vm_flags & VM_SHARED)) 17957e660872SDavid Howells continue; 17967e660872SDavid Howells 17977e660872SDavid Howells region = vma->vm_region; 17987e660872SDavid Howells r_size = region->vm_top - region->vm_start; 17997e660872SDavid Howells r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; 18007e660872SDavid Howells 18017e660872SDavid Howells if (r_top > newsize) { 18027e660872SDavid Howells region->vm_top -= r_top - newsize; 18037e660872SDavid Howells if (region->vm_end > region->vm_top) 18047e660872SDavid Howells region->vm_end = region->vm_top; 18057e660872SDavid Howells } 18067e660872SDavid Howells } 18077e660872SDavid Howells 18081acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 18097e660872SDavid Howells up_write(&nommu_region_sem); 18107e660872SDavid Howells return 0; 18117e660872SDavid Howells } 1812c9b1d098SAndrew Shewmaker 1813c9b1d098SAndrew Shewmaker /* 1814c9b1d098SAndrew Shewmaker * Initialise sysctl_user_reserve_kbytes. 1815c9b1d098SAndrew Shewmaker * 1816c9b1d098SAndrew Shewmaker * This is intended to prevent a user from starting a single memory hogging 1817c9b1d098SAndrew Shewmaker * process, such that they cannot recover (kill the hog) in OVERCOMMIT_NEVER 1818c9b1d098SAndrew Shewmaker * mode. 1819c9b1d098SAndrew Shewmaker * 1820c9b1d098SAndrew Shewmaker * The default value is min(3% of free memory, 128MB) 1821c9b1d098SAndrew Shewmaker * 128MB is enough to recover with sshd/login, bash, and top/kill. 1822c9b1d098SAndrew Shewmaker */ 1823c9b1d098SAndrew Shewmaker static int __meminit init_user_reserve(void) 1824c9b1d098SAndrew Shewmaker { 1825c9b1d098SAndrew Shewmaker unsigned long free_kbytes; 1826c9b1d098SAndrew Shewmaker 1827c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 1828c9b1d098SAndrew Shewmaker 1829c9b1d098SAndrew Shewmaker sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17); 1830c9b1d098SAndrew Shewmaker return 0; 1831c9b1d098SAndrew Shewmaker } 1832a4bc6fc7SPaul Gortmaker subsys_initcall(init_user_reserve); 18334eeab4f5SAndrew Shewmaker 18344eeab4f5SAndrew Shewmaker /* 18354eeab4f5SAndrew Shewmaker * Initialise sysctl_admin_reserve_kbytes. 18364eeab4f5SAndrew Shewmaker * 18374eeab4f5SAndrew Shewmaker * The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin 18384eeab4f5SAndrew Shewmaker * to log in and kill a memory hogging process. 18394eeab4f5SAndrew Shewmaker * 18404eeab4f5SAndrew Shewmaker * Systems with more than 256MB will reserve 8MB, enough to recover 18414eeab4f5SAndrew Shewmaker * with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will 18424eeab4f5SAndrew Shewmaker * only reserve 3% of free pages by default. 18434eeab4f5SAndrew Shewmaker */ 18444eeab4f5SAndrew Shewmaker static int __meminit init_admin_reserve(void) 18454eeab4f5SAndrew Shewmaker { 18464eeab4f5SAndrew Shewmaker unsigned long free_kbytes; 18474eeab4f5SAndrew Shewmaker 1848c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 18494eeab4f5SAndrew Shewmaker 18504eeab4f5SAndrew Shewmaker sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13); 18514eeab4f5SAndrew Shewmaker return 0; 18524eeab4f5SAndrew Shewmaker } 1853a4bc6fc7SPaul Gortmaker subsys_initcall(init_admin_reserve); 1854