1457c8996SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * linux/mm/nommu.c 41da177e4SLinus Torvalds * 51da177e4SLinus Torvalds * Replacement code for mm functions to support CPU's that don't 61da177e4SLinus Torvalds * have any form of memory management unit (thus no virtual memory). 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * See Documentation/nommu-mmap.txt 91da177e4SLinus Torvalds * 108feae131SDavid Howells * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com> 111da177e4SLinus Torvalds * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> 121da177e4SLinus Torvalds * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> 131da177e4SLinus Torvalds * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> 1429c185e5SPaul Mundt * Copyright (c) 2007-2010 Paul Mundt <lethal@linux-sh.org> 151da177e4SLinus Torvalds */ 161da177e4SLinus Torvalds 17b1de0d13SMitchel Humpherys #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18b1de0d13SMitchel Humpherys 19b95f1b31SPaul Gortmaker #include <linux/export.h> 201da177e4SLinus Torvalds #include <linux/mm.h> 216e84f315SIngo Molnar #include <linux/sched/mm.h> 22615d6e87SDavidlohr Bueso #include <linux/vmacache.h> 231da177e4SLinus Torvalds #include <linux/mman.h> 241da177e4SLinus Torvalds #include <linux/swap.h> 251da177e4SLinus Torvalds #include <linux/file.h> 261da177e4SLinus Torvalds #include <linux/highmem.h> 271da177e4SLinus Torvalds #include <linux/pagemap.h> 281da177e4SLinus Torvalds #include <linux/slab.h> 291da177e4SLinus Torvalds #include <linux/vmalloc.h> 301da177e4SLinus Torvalds #include <linux/blkdev.h> 311da177e4SLinus Torvalds #include <linux/backing-dev.h> 323b32123dSGideon Israel Dsouza #include <linux/compiler.h> 331da177e4SLinus Torvalds #include <linux/mount.h> 341da177e4SLinus Torvalds #include <linux/personality.h> 351da177e4SLinus Torvalds #include <linux/security.h> 361da177e4SLinus Torvalds #include <linux/syscalls.h> 37120a795dSAl Viro #include <linux/audit.h> 38b1de0d13SMitchel Humpherys #include <linux/printk.h> 391da177e4SLinus Torvalds 407c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 411da177e4SLinus Torvalds #include <asm/tlb.h> 421da177e4SLinus Torvalds #include <asm/tlbflush.h> 43eb8cdec4SBernd Schmidt #include <asm/mmu_context.h> 448feae131SDavid Howells #include "internal.h" 458feae131SDavid Howells 461da177e4SLinus Torvalds void *high_memory; 47944b6874SArnd Bergmann EXPORT_SYMBOL(high_memory); 481da177e4SLinus Torvalds struct page *mem_map; 491da177e4SLinus Torvalds unsigned long max_mapnr; 505b8bf307Sgchen gchen EXPORT_SYMBOL(max_mapnr); 514266c97aSHugh Dickins unsigned long highest_memmap_pfn; 52fc4d5c29SDavid Howells int sysctl_nr_trim_pages = CONFIG_NOMMU_INITIAL_TRIM_EXCESS; 531da177e4SLinus Torvalds int heap_stack_gap = 0; 541da177e4SLinus Torvalds 5533e5d769SDavid Howells atomic_long_t mmap_pages_allocated; 568feae131SDavid Howells 571da177e4SLinus Torvalds EXPORT_SYMBOL(mem_map); 581da177e4SLinus Torvalds 598feae131SDavid Howells /* list of mapped, potentially shareable regions */ 608feae131SDavid Howells static struct kmem_cache *vm_region_jar; 618feae131SDavid Howells struct rb_root nommu_region_tree = RB_ROOT; 628feae131SDavid Howells DECLARE_RWSEM(nommu_region_sem); 631da177e4SLinus Torvalds 64f0f37e2fSAlexey Dobriyan const struct vm_operations_struct generic_file_vm_ops = { 651da177e4SLinus Torvalds }; 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds /* 681da177e4SLinus Torvalds * Return the total memory allocated for this pointer, not 691da177e4SLinus Torvalds * just what the caller asked for. 701da177e4SLinus Torvalds * 711da177e4SLinus Torvalds * Doesn't have to be accurate, i.e. may have races. 721da177e4SLinus Torvalds */ 731da177e4SLinus Torvalds unsigned int kobjsize(const void *objp) 741da177e4SLinus Torvalds { 751da177e4SLinus Torvalds struct page *page; 761da177e4SLinus Torvalds 774016a139SMichael Hennerich /* 784016a139SMichael Hennerich * If the object we have should not have ksize performed on it, 794016a139SMichael Hennerich * return size of 0 804016a139SMichael Hennerich */ 815a1603beSPaul Mundt if (!objp || !virt_addr_valid(objp)) 826cfd53fcSPaul Mundt return 0; 836cfd53fcSPaul Mundt 846cfd53fcSPaul Mundt page = virt_to_head_page(objp); 856cfd53fcSPaul Mundt 866cfd53fcSPaul Mundt /* 876cfd53fcSPaul Mundt * If the allocator sets PageSlab, we know the pointer came from 886cfd53fcSPaul Mundt * kmalloc(). 896cfd53fcSPaul Mundt */ 901da177e4SLinus Torvalds if (PageSlab(page)) 911da177e4SLinus Torvalds return ksize(objp); 921da177e4SLinus Torvalds 936cfd53fcSPaul Mundt /* 94ab2e83eaSPaul Mundt * If it's not a compound page, see if we have a matching VMA 95ab2e83eaSPaul Mundt * region. This test is intentionally done in reverse order, 96ab2e83eaSPaul Mundt * so if there's no VMA, we still fall through and hand back 97ab2e83eaSPaul Mundt * PAGE_SIZE for 0-order pages. 98ab2e83eaSPaul Mundt */ 99ab2e83eaSPaul Mundt if (!PageCompound(page)) { 100ab2e83eaSPaul Mundt struct vm_area_struct *vma; 101ab2e83eaSPaul Mundt 102ab2e83eaSPaul Mundt vma = find_vma(current->mm, (unsigned long)objp); 103ab2e83eaSPaul Mundt if (vma) 104ab2e83eaSPaul Mundt return vma->vm_end - vma->vm_start; 105ab2e83eaSPaul Mundt } 106ab2e83eaSPaul Mundt 107ab2e83eaSPaul Mundt /* 1086cfd53fcSPaul Mundt * The ksize() function is only guaranteed to work for pointers 1095a1603beSPaul Mundt * returned by kmalloc(). So handle arbitrary pointers here. 1106cfd53fcSPaul Mundt */ 111a50b854eSMatthew Wilcox (Oracle) return page_size(page); 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds 114dfc2f91aSPaul Mundt /** 115dfc2f91aSPaul Mundt * follow_pfn - look up PFN at a user virtual address 116dfc2f91aSPaul Mundt * @vma: memory mapping 117dfc2f91aSPaul Mundt * @address: user virtual address 118dfc2f91aSPaul Mundt * @pfn: location to store found PFN 119dfc2f91aSPaul Mundt * 120dfc2f91aSPaul Mundt * Only IO mappings and raw PFN mappings are allowed. 121dfc2f91aSPaul Mundt * 122dfc2f91aSPaul Mundt * Returns zero and the pfn at @pfn on success, -ve otherwise. 123dfc2f91aSPaul Mundt */ 124dfc2f91aSPaul Mundt int follow_pfn(struct vm_area_struct *vma, unsigned long address, 125dfc2f91aSPaul Mundt unsigned long *pfn) 126dfc2f91aSPaul Mundt { 127dfc2f91aSPaul Mundt if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) 128dfc2f91aSPaul Mundt return -EINVAL; 129dfc2f91aSPaul Mundt 130dfc2f91aSPaul Mundt *pfn = address >> PAGE_SHIFT; 131dfc2f91aSPaul Mundt return 0; 132dfc2f91aSPaul Mundt } 133dfc2f91aSPaul Mundt EXPORT_SYMBOL(follow_pfn); 134dfc2f91aSPaul Mundt 135f1c4069eSJoonsoo Kim LIST_HEAD(vmap_area_list); 1361da177e4SLinus Torvalds 137b3bdda02SChristoph Lameter void vfree(const void *addr) 1381da177e4SLinus Torvalds { 1391da177e4SLinus Torvalds kfree(addr); 1401da177e4SLinus Torvalds } 141b5073173SPaul Mundt EXPORT_SYMBOL(vfree); 1421da177e4SLinus Torvalds 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 175*d8ed45c5SMichel 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; 179*d8ed45c5SMichel 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 /** 2941af446edSPaul Mundt * vmalloc_exec - allocate virtually contiguous, executable memory 2951af446edSPaul Mundt * @size: allocation size 2961af446edSPaul Mundt * 2971af446edSPaul Mundt * Kernel-internal function to allocate enough pages to cover @size 2981af446edSPaul Mundt * the page level allocator and map them into contiguous and 2991af446edSPaul Mundt * executable kernel virtual space. 3001af446edSPaul Mundt * 3011af446edSPaul Mundt * For tight control over page level allocator and protection flags 3021af446edSPaul Mundt * use __vmalloc() instead. 3031af446edSPaul Mundt */ 3041af446edSPaul Mundt 3051af446edSPaul Mundt void *vmalloc_exec(unsigned long size) 3061af446edSPaul Mundt { 30788dca4caSChristoph Hellwig return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM); 3081af446edSPaul Mundt } 3091af446edSPaul Mundt 310b5073173SPaul Mundt /** 311b5073173SPaul Mundt * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 3121da177e4SLinus Torvalds * @size: allocation size 3131da177e4SLinus Torvalds * 3141da177e4SLinus Torvalds * Allocate enough 32bit PA addressable pages to cover @size from the 315e1c05067SMasahiro Yamada * page level allocator and map them into contiguous kernel virtual space. 3161da177e4SLinus Torvalds */ 3171da177e4SLinus Torvalds void *vmalloc_32(unsigned long size) 3181da177e4SLinus Torvalds { 31988dca4caSChristoph Hellwig return __vmalloc(size, GFP_KERNEL); 3201da177e4SLinus Torvalds } 321b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32); 322b5073173SPaul Mundt 323b5073173SPaul Mundt /** 324b5073173SPaul Mundt * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 325b5073173SPaul Mundt * @size: allocation size 326b5073173SPaul Mundt * 327b5073173SPaul Mundt * The resulting memory area is 32bit addressable and zeroed so it can be 328b5073173SPaul Mundt * mapped to userspace without leaking data. 329f905bc44SPaul Mundt * 330f905bc44SPaul Mundt * VM_USERMAP is set on the corresponding VMA so that subsequent calls to 331f905bc44SPaul Mundt * remap_vmalloc_range() are permissible. 332b5073173SPaul Mundt */ 333b5073173SPaul Mundt void *vmalloc_32_user(unsigned long size) 334b5073173SPaul Mundt { 335f905bc44SPaul Mundt /* 336f905bc44SPaul Mundt * We'll have to sort out the ZONE_DMA bits for 64-bit, 337f905bc44SPaul Mundt * but for now this can simply use vmalloc_user() directly. 338f905bc44SPaul Mundt */ 339f905bc44SPaul Mundt return vmalloc_user(size); 340b5073173SPaul Mundt } 341b5073173SPaul Mundt EXPORT_SYMBOL(vmalloc_32_user); 3421da177e4SLinus Torvalds 3431da177e4SLinus Torvalds void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) 3441da177e4SLinus Torvalds { 3451da177e4SLinus Torvalds BUG(); 3461da177e4SLinus Torvalds return NULL; 3471da177e4SLinus Torvalds } 348b5073173SPaul Mundt EXPORT_SYMBOL(vmap); 3491da177e4SLinus Torvalds 350b3bdda02SChristoph Lameter void vunmap(const void *addr) 3511da177e4SLinus Torvalds { 3521da177e4SLinus Torvalds BUG(); 3531da177e4SLinus Torvalds } 354b5073173SPaul Mundt EXPORT_SYMBOL(vunmap); 3551da177e4SLinus Torvalds 356d4efd79aSChristoph Hellwig void *vm_map_ram(struct page **pages, unsigned int count, int node) 357eb6434d9SPaul Mundt { 358eb6434d9SPaul Mundt BUG(); 359eb6434d9SPaul Mundt return NULL; 360eb6434d9SPaul Mundt } 361eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_map_ram); 362eb6434d9SPaul Mundt 363eb6434d9SPaul Mundt void vm_unmap_ram(const void *mem, unsigned int count) 364eb6434d9SPaul Mundt { 365eb6434d9SPaul Mundt BUG(); 366eb6434d9SPaul Mundt } 367eb6434d9SPaul Mundt EXPORT_SYMBOL(vm_unmap_ram); 368eb6434d9SPaul Mundt 369eb6434d9SPaul Mundt void vm_unmap_aliases(void) 370eb6434d9SPaul Mundt { 371eb6434d9SPaul Mundt } 372eb6434d9SPaul Mundt EXPORT_SYMBOL_GPL(vm_unmap_aliases); 373eb6434d9SPaul Mundt 374cd12909cSDavid Vrabel struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) 37529c185e5SPaul Mundt { 37629c185e5SPaul Mundt BUG(); 37729c185e5SPaul Mundt return NULL; 37829c185e5SPaul Mundt } 37929c185e5SPaul Mundt EXPORT_SYMBOL_GPL(alloc_vm_area); 38029c185e5SPaul Mundt 38129c185e5SPaul Mundt void free_vm_area(struct vm_struct *area) 38229c185e5SPaul Mundt { 38329c185e5SPaul Mundt BUG(); 38429c185e5SPaul Mundt } 38529c185e5SPaul Mundt EXPORT_SYMBOL_GPL(free_vm_area); 38629c185e5SPaul Mundt 387b5073173SPaul Mundt int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, 388b5073173SPaul Mundt struct page *page) 389b5073173SPaul Mundt { 390b5073173SPaul Mundt return -EINVAL; 391b5073173SPaul Mundt } 392b5073173SPaul Mundt EXPORT_SYMBOL(vm_insert_page); 393b5073173SPaul Mundt 394a667d745SSouptick Joarder int vm_map_pages(struct vm_area_struct *vma, struct page **pages, 395a667d745SSouptick Joarder unsigned long num) 396a667d745SSouptick Joarder { 397a667d745SSouptick Joarder return -EINVAL; 398a667d745SSouptick Joarder } 399a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages); 400a667d745SSouptick Joarder 401a667d745SSouptick Joarder int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages, 402a667d745SSouptick Joarder unsigned long num) 403a667d745SSouptick Joarder { 404a667d745SSouptick Joarder return -EINVAL; 405a667d745SSouptick Joarder } 406a667d745SSouptick Joarder EXPORT_SYMBOL(vm_map_pages_zero); 407a667d745SSouptick Joarder 4081eeb66a1SChristoph Hellwig /* 4091da177e4SLinus Torvalds * sys_brk() for the most part doesn't need the global kernel 4101da177e4SLinus Torvalds * lock, except when an application is doing something nasty 4111da177e4SLinus Torvalds * like trying to un-brk an area that has already been mapped 4121da177e4SLinus Torvalds * to a regular file. in this case, the unmapping will need 4131da177e4SLinus Torvalds * to invoke file system routines that need the global lock. 4141da177e4SLinus Torvalds */ 4156a6160a7SHeiko Carstens SYSCALL_DEFINE1(brk, unsigned long, brk) 4161da177e4SLinus Torvalds { 4171da177e4SLinus Torvalds struct mm_struct *mm = current->mm; 4181da177e4SLinus Torvalds 4191da177e4SLinus Torvalds if (brk < mm->start_brk || brk > mm->context.end_brk) 4201da177e4SLinus Torvalds return mm->brk; 4211da177e4SLinus Torvalds 4221da177e4SLinus Torvalds if (mm->brk == brk) 4231da177e4SLinus Torvalds return mm->brk; 4241da177e4SLinus Torvalds 4251da177e4SLinus Torvalds /* 4261da177e4SLinus Torvalds * Always allow shrinking brk 4271da177e4SLinus Torvalds */ 4281da177e4SLinus Torvalds if (brk <= mm->brk) { 4291da177e4SLinus Torvalds mm->brk = brk; 4301da177e4SLinus Torvalds return brk; 4311da177e4SLinus Torvalds } 4321da177e4SLinus Torvalds 4331da177e4SLinus Torvalds /* 4341da177e4SLinus Torvalds * Ok, looks good - let it rip. 4351da177e4SLinus Torvalds */ 436a75a2df6SChristoph Hellwig flush_icache_user_range(mm->brk, brk); 4371da177e4SLinus Torvalds return mm->brk = brk; 4381da177e4SLinus Torvalds } 4391da177e4SLinus Torvalds 4408feae131SDavid Howells /* 4413edf41d8Sseokhoon.yoon * initialise the percpu counter for VM and region record slabs 4428feae131SDavid Howells */ 4438feae131SDavid Howells void __init mmap_init(void) 4441da177e4SLinus Torvalds { 44500a62ce9SKOSAKI Motohiro int ret; 44600a62ce9SKOSAKI Motohiro 447908c7f19STejun Heo ret = percpu_counter_init(&vm_committed_as, 0, GFP_KERNEL); 44800a62ce9SKOSAKI Motohiro VM_BUG_ON(ret); 4495d097056SVladimir Davydov vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC|SLAB_ACCOUNT); 4508feae131SDavid Howells } 4511da177e4SLinus Torvalds 4528feae131SDavid Howells /* 4538feae131SDavid Howells * validate the region tree 4548feae131SDavid Howells * - the caller must hold the region lock 4558feae131SDavid Howells */ 4568feae131SDavid Howells #ifdef CONFIG_DEBUG_NOMMU_REGIONS 4578feae131SDavid Howells static noinline void validate_nommu_regions(void) 4588feae131SDavid Howells { 4598feae131SDavid Howells struct vm_region *region, *last; 4608feae131SDavid Howells struct rb_node *p, *lastp; 4611da177e4SLinus Torvalds 4628feae131SDavid Howells lastp = rb_first(&nommu_region_tree); 4638feae131SDavid Howells if (!lastp) 4648feae131SDavid Howells return; 4658feae131SDavid Howells 4668feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 467c9427bc0SGeliang Tang BUG_ON(last->vm_end <= last->vm_start); 468c9427bc0SGeliang Tang BUG_ON(last->vm_top < last->vm_end); 4698feae131SDavid Howells 4708feae131SDavid Howells while ((p = rb_next(lastp))) { 4718feae131SDavid Howells region = rb_entry(p, struct vm_region, vm_rb); 4728feae131SDavid Howells last = rb_entry(lastp, struct vm_region, vm_rb); 4738feae131SDavid Howells 474c9427bc0SGeliang Tang BUG_ON(region->vm_end <= region->vm_start); 475c9427bc0SGeliang Tang BUG_ON(region->vm_top < region->vm_end); 476c9427bc0SGeliang Tang BUG_ON(region->vm_start < last->vm_top); 4778feae131SDavid Howells 4788feae131SDavid Howells lastp = p; 4791da177e4SLinus Torvalds } 4801da177e4SLinus Torvalds } 4818feae131SDavid Howells #else 48233e5d769SDavid Howells static void validate_nommu_regions(void) 48333e5d769SDavid Howells { 48433e5d769SDavid Howells } 4858feae131SDavid Howells #endif 4868feae131SDavid Howells 4878feae131SDavid Howells /* 4888feae131SDavid Howells * add a region into the global tree 4898feae131SDavid Howells */ 4908feae131SDavid Howells static void add_nommu_region(struct vm_region *region) 4918feae131SDavid Howells { 4928feae131SDavid Howells struct vm_region *pregion; 4938feae131SDavid Howells struct rb_node **p, *parent; 4948feae131SDavid Howells 4958feae131SDavid Howells validate_nommu_regions(); 4968feae131SDavid Howells 4978feae131SDavid Howells parent = NULL; 4988feae131SDavid Howells p = &nommu_region_tree.rb_node; 4998feae131SDavid Howells while (*p) { 5008feae131SDavid Howells parent = *p; 5018feae131SDavid Howells pregion = rb_entry(parent, struct vm_region, vm_rb); 5028feae131SDavid Howells if (region->vm_start < pregion->vm_start) 5038feae131SDavid Howells p = &(*p)->rb_left; 5048feae131SDavid Howells else if (region->vm_start > pregion->vm_start) 5058feae131SDavid Howells p = &(*p)->rb_right; 5068feae131SDavid Howells else if (pregion == region) 5078feae131SDavid Howells return; 5088feae131SDavid Howells else 5098feae131SDavid Howells BUG(); 5108feae131SDavid Howells } 5118feae131SDavid Howells 5128feae131SDavid Howells rb_link_node(®ion->vm_rb, parent, p); 5138feae131SDavid Howells rb_insert_color(®ion->vm_rb, &nommu_region_tree); 5148feae131SDavid Howells 5158feae131SDavid Howells validate_nommu_regions(); 5168feae131SDavid Howells } 5178feae131SDavid Howells 5188feae131SDavid Howells /* 5198feae131SDavid Howells * delete a region from the global tree 5208feae131SDavid Howells */ 5218feae131SDavid Howells static void delete_nommu_region(struct vm_region *region) 5228feae131SDavid Howells { 5238feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5248feae131SDavid Howells 5258feae131SDavid Howells validate_nommu_regions(); 5268feae131SDavid Howells rb_erase(®ion->vm_rb, &nommu_region_tree); 5278feae131SDavid Howells validate_nommu_regions(); 5288feae131SDavid Howells } 5298feae131SDavid Howells 5308feae131SDavid Howells /* 5318feae131SDavid Howells * free a contiguous series of pages 5328feae131SDavid Howells */ 5338feae131SDavid Howells static void free_page_series(unsigned long from, unsigned long to) 5348feae131SDavid Howells { 5358feae131SDavid Howells for (; from < to; from += PAGE_SIZE) { 5368feae131SDavid Howells struct page *page = virt_to_page(from); 5378feae131SDavid Howells 53833e5d769SDavid Howells atomic_long_dec(&mmap_pages_allocated); 5398feae131SDavid Howells put_page(page); 5408feae131SDavid Howells } 5418feae131SDavid Howells } 5428feae131SDavid Howells 5438feae131SDavid Howells /* 5448feae131SDavid Howells * release a reference to a region 54533e5d769SDavid Howells * - the caller must hold the region semaphore for writing, which this releases 546dd8632a1SPaul Mundt * - the region may not have been added to the tree yet, in which case vm_top 5478feae131SDavid Howells * will equal vm_start 5488feae131SDavid Howells */ 5498feae131SDavid Howells static void __put_nommu_region(struct vm_region *region) 5508feae131SDavid Howells __releases(nommu_region_sem) 5518feae131SDavid Howells { 5528feae131SDavid Howells BUG_ON(!nommu_region_tree.rb_node); 5538feae131SDavid Howells 5541e2ae599SDavid Howells if (--region->vm_usage == 0) { 555dd8632a1SPaul Mundt if (region->vm_top > region->vm_start) 5568feae131SDavid Howells delete_nommu_region(region); 5578feae131SDavid Howells up_write(&nommu_region_sem); 5588feae131SDavid Howells 5598feae131SDavid Howells if (region->vm_file) 5608feae131SDavid Howells fput(region->vm_file); 5618feae131SDavid Howells 5628feae131SDavid Howells /* IO memory and memory shared directly out of the pagecache 5638feae131SDavid Howells * from ramfs/tmpfs mustn't be released here */ 56422cc877bSLeon Romanovsky if (region->vm_flags & VM_MAPPED_COPY) 565dd8632a1SPaul Mundt free_page_series(region->vm_start, region->vm_top); 5668feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 5678feae131SDavid Howells } else { 5688feae131SDavid Howells up_write(&nommu_region_sem); 5698feae131SDavid Howells } 5708feae131SDavid Howells } 5718feae131SDavid Howells 5728feae131SDavid Howells /* 5738feae131SDavid Howells * release a reference to a region 5748feae131SDavid Howells */ 5758feae131SDavid Howells static void put_nommu_region(struct vm_region *region) 5768feae131SDavid Howells { 5778feae131SDavid Howells down_write(&nommu_region_sem); 5788feae131SDavid Howells __put_nommu_region(region); 5798feae131SDavid Howells } 5801da177e4SLinus Torvalds 5813034097aSDavid Howells /* 5823034097aSDavid Howells * add a VMA into a process's mm_struct in the appropriate place in the list 5838feae131SDavid Howells * and tree and add to the address space's page tree also if not an anonymous 5848feae131SDavid Howells * page 5853034097aSDavid Howells * - should be called with mm->mmap_sem held writelocked 5863034097aSDavid Howells */ 5878feae131SDavid Howells static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) 5883034097aSDavid Howells { 5896038def0SNamhyung Kim struct vm_area_struct *pvma, *prev; 5908feae131SDavid Howells struct address_space *mapping; 5916038def0SNamhyung Kim struct rb_node **p, *parent, *rb_prev; 5923034097aSDavid Howells 5938feae131SDavid Howells BUG_ON(!vma->vm_region); 5948feae131SDavid Howells 5958feae131SDavid Howells mm->map_count++; 5968feae131SDavid Howells vma->vm_mm = mm; 5978feae131SDavid Howells 5988feae131SDavid Howells /* add the VMA to the mapping */ 5998feae131SDavid Howells if (vma->vm_file) { 6008feae131SDavid Howells mapping = vma->vm_file->f_mapping; 6018feae131SDavid Howells 60283cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 6038feae131SDavid Howells flush_dcache_mmap_lock(mapping); 6046b2dbba8SMichel Lespinasse vma_interval_tree_insert(vma, &mapping->i_mmap); 6058feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 60683cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 6078feae131SDavid Howells } 6088feae131SDavid Howells 6098feae131SDavid Howells /* add the VMA to the tree */ 6106038def0SNamhyung Kim parent = rb_prev = NULL; 6118feae131SDavid Howells p = &mm->mm_rb.rb_node; 6128feae131SDavid Howells while (*p) { 6138feae131SDavid Howells parent = *p; 6148feae131SDavid Howells pvma = rb_entry(parent, struct vm_area_struct, vm_rb); 6158feae131SDavid Howells 6168feae131SDavid Howells /* sort by: start addr, end addr, VMA struct addr in that order 6178feae131SDavid Howells * (the latter is necessary as we may get identical VMAs) */ 6188feae131SDavid Howells if (vma->vm_start < pvma->vm_start) 6198feae131SDavid Howells p = &(*p)->rb_left; 6206038def0SNamhyung Kim else if (vma->vm_start > pvma->vm_start) { 6216038def0SNamhyung Kim rb_prev = parent; 6228feae131SDavid Howells p = &(*p)->rb_right; 6236038def0SNamhyung Kim } else if (vma->vm_end < pvma->vm_end) 6248feae131SDavid Howells p = &(*p)->rb_left; 6256038def0SNamhyung Kim else if (vma->vm_end > pvma->vm_end) { 6266038def0SNamhyung Kim rb_prev = parent; 6278feae131SDavid Howells p = &(*p)->rb_right; 6286038def0SNamhyung Kim } else if (vma < pvma) 6298feae131SDavid Howells p = &(*p)->rb_left; 6306038def0SNamhyung Kim else if (vma > pvma) { 6316038def0SNamhyung Kim rb_prev = parent; 6328feae131SDavid Howells p = &(*p)->rb_right; 6336038def0SNamhyung Kim } else 6348feae131SDavid Howells BUG(); 6358feae131SDavid Howells } 6368feae131SDavid Howells 6378feae131SDavid Howells rb_link_node(&vma->vm_rb, parent, p); 6388feae131SDavid Howells rb_insert_color(&vma->vm_rb, &mm->mm_rb); 6398feae131SDavid Howells 6408feae131SDavid Howells /* add VMA to the VMA list also */ 6416038def0SNamhyung Kim prev = NULL; 6426038def0SNamhyung Kim if (rb_prev) 6436038def0SNamhyung Kim prev = rb_entry(rb_prev, struct vm_area_struct, vm_rb); 6443034097aSDavid Howells 645aba6dfb7SWei Yang __vma_link_list(mm, vma, prev); 6468feae131SDavid Howells } 6478feae131SDavid Howells 6488feae131SDavid Howells /* 6498feae131SDavid Howells * delete a VMA from its owning mm_struct and address space 6508feae131SDavid Howells */ 6518feae131SDavid Howells static void delete_vma_from_mm(struct vm_area_struct *vma) 6528feae131SDavid Howells { 653615d6e87SDavidlohr Bueso int i; 6548feae131SDavid Howells struct address_space *mapping; 6558feae131SDavid Howells struct mm_struct *mm = vma->vm_mm; 656615d6e87SDavidlohr Bueso struct task_struct *curr = current; 6578feae131SDavid Howells 6588feae131SDavid Howells mm->map_count--; 659615d6e87SDavidlohr Bueso for (i = 0; i < VMACACHE_SIZE; i++) { 660615d6e87SDavidlohr Bueso /* if the vma is cached, invalidate the entire cache */ 661314ff785SIngo Molnar if (curr->vmacache.vmas[i] == vma) { 662e020d5bdSSteven Miao vmacache_invalidate(mm); 663615d6e87SDavidlohr Bueso break; 664615d6e87SDavidlohr Bueso } 665615d6e87SDavidlohr Bueso } 6668feae131SDavid Howells 6678feae131SDavid Howells /* remove the VMA from the mapping */ 6688feae131SDavid Howells if (vma->vm_file) { 6698feae131SDavid Howells mapping = vma->vm_file->f_mapping; 6708feae131SDavid Howells 67183cde9e8SDavidlohr Bueso i_mmap_lock_write(mapping); 6728feae131SDavid Howells flush_dcache_mmap_lock(mapping); 6736b2dbba8SMichel Lespinasse vma_interval_tree_remove(vma, &mapping->i_mmap); 6748feae131SDavid Howells flush_dcache_mmap_unlock(mapping); 67583cde9e8SDavidlohr Bueso i_mmap_unlock_write(mapping); 6768feae131SDavid Howells } 6778feae131SDavid Howells 6788feae131SDavid Howells /* remove from the MM's tree and list */ 6798feae131SDavid Howells rb_erase(&vma->vm_rb, &mm->mm_rb); 680b951bf2cSNamhyung Kim 6811b9fc5b2SWei Yang __vma_unlink_list(mm, vma); 6828feae131SDavid Howells } 6838feae131SDavid Howells 6848feae131SDavid Howells /* 6858feae131SDavid Howells * destroy a VMA record 6868feae131SDavid Howells */ 6878feae131SDavid Howells static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) 6888feae131SDavid Howells { 6898feae131SDavid Howells if (vma->vm_ops && vma->vm_ops->close) 6908feae131SDavid Howells vma->vm_ops->close(vma); 691e9714acfSKonstantin Khlebnikov if (vma->vm_file) 6928feae131SDavid Howells fput(vma->vm_file); 6938feae131SDavid Howells put_nommu_region(vma->vm_region); 6943928d4f5SLinus Torvalds vm_area_free(vma); 6953034097aSDavid Howells } 6963034097aSDavid Howells 6973034097aSDavid Howells /* 6983034097aSDavid Howells * look up the first VMA in which addr resides, NULL if none 6993034097aSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 7003034097aSDavid Howells */ 7013034097aSDavid Howells struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) 7023034097aSDavid Howells { 7038feae131SDavid Howells struct vm_area_struct *vma; 7043034097aSDavid Howells 7058feae131SDavid Howells /* check the cache first */ 706615d6e87SDavidlohr Bueso vma = vmacache_find(mm, addr); 707615d6e87SDavidlohr Bueso if (likely(vma)) 7088feae131SDavid Howells return vma; 7098feae131SDavid Howells 710e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 7118feae131SDavid Howells * resides) */ 712e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 7138feae131SDavid Howells if (vma->vm_start > addr) 7148feae131SDavid Howells return NULL; 7158feae131SDavid Howells if (vma->vm_end > addr) { 716615d6e87SDavidlohr Bueso vmacache_update(addr, vma); 7178feae131SDavid Howells return vma; 7183034097aSDavid Howells } 7198feae131SDavid Howells } 7203034097aSDavid Howells 7213034097aSDavid Howells return NULL; 7223034097aSDavid Howells } 7233034097aSDavid Howells EXPORT_SYMBOL(find_vma); 7243034097aSDavid Howells 7253034097aSDavid Howells /* 726930e652aSDavid Howells * find a VMA 727930e652aSDavid Howells * - we don't extend stack VMAs under NOMMU conditions 728930e652aSDavid Howells */ 729930e652aSDavid Howells struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) 730930e652aSDavid Howells { 7317561e8caSDavid Howells return find_vma(mm, addr); 732930e652aSDavid Howells } 733930e652aSDavid Howells 7348feae131SDavid Howells /* 7358feae131SDavid Howells * expand a stack to a given address 7368feae131SDavid Howells * - not supported under NOMMU conditions 7378feae131SDavid Howells */ 73857c8f63eSGreg Ungerer int expand_stack(struct vm_area_struct *vma, unsigned long address) 73957c8f63eSGreg Ungerer { 74057c8f63eSGreg Ungerer return -ENOMEM; 74157c8f63eSGreg Ungerer } 74257c8f63eSGreg Ungerer 743930e652aSDavid Howells /* 7446fa5f80bSDavid Howells * look up the first VMA exactly that exactly matches addr 7456fa5f80bSDavid Howells * - should be called with mm->mmap_sem at least held readlocked 7466fa5f80bSDavid Howells */ 7478feae131SDavid Howells static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, 7488feae131SDavid Howells unsigned long addr, 7498feae131SDavid Howells unsigned long len) 7501da177e4SLinus Torvalds { 7511da177e4SLinus Torvalds struct vm_area_struct *vma; 7528feae131SDavid Howells unsigned long end = addr + len; 7531da177e4SLinus Torvalds 7548feae131SDavid Howells /* check the cache first */ 755615d6e87SDavidlohr Bueso vma = vmacache_find_exact(mm, addr, end); 756615d6e87SDavidlohr Bueso if (vma) 7571da177e4SLinus Torvalds return vma; 7588feae131SDavid Howells 759e922c4c5SNamhyung Kim /* trawl the list (there may be multiple mappings in which addr 7608feae131SDavid Howells * resides) */ 761e922c4c5SNamhyung Kim for (vma = mm->mmap; vma; vma = vma->vm_next) { 7628feae131SDavid Howells if (vma->vm_start < addr) 7638feae131SDavid Howells continue; 7648feae131SDavid Howells if (vma->vm_start > addr) 7658feae131SDavid Howells return NULL; 7668feae131SDavid Howells if (vma->vm_end == end) { 767615d6e87SDavidlohr Bueso vmacache_update(addr, vma); 7688feae131SDavid Howells return vma; 7698feae131SDavid Howells } 7701da177e4SLinus Torvalds } 7711da177e4SLinus Torvalds 7721da177e4SLinus Torvalds return NULL; 7731da177e4SLinus Torvalds } 7741da177e4SLinus Torvalds 7753034097aSDavid Howells /* 7761da177e4SLinus Torvalds * determine whether a mapping should be permitted and, if so, what sort of 7771da177e4SLinus Torvalds * mapping we're capable of supporting 7781da177e4SLinus Torvalds */ 7791da177e4SLinus Torvalds static int validate_mmap_request(struct file *file, 7801da177e4SLinus Torvalds unsigned long addr, 7811da177e4SLinus Torvalds unsigned long len, 7821da177e4SLinus Torvalds unsigned long prot, 7831da177e4SLinus Torvalds unsigned long flags, 7841da177e4SLinus Torvalds unsigned long pgoff, 7851da177e4SLinus Torvalds unsigned long *_capabilities) 7861da177e4SLinus Torvalds { 7878feae131SDavid Howells unsigned long capabilities, rlen; 7881da177e4SLinus Torvalds int ret; 7891da177e4SLinus Torvalds 7901da177e4SLinus Torvalds /* do the simple checks first */ 79122cc877bSLeon Romanovsky if (flags & MAP_FIXED) 7921da177e4SLinus Torvalds return -EINVAL; 7931da177e4SLinus Torvalds 7941da177e4SLinus Torvalds if ((flags & MAP_TYPE) != MAP_PRIVATE && 7951da177e4SLinus Torvalds (flags & MAP_TYPE) != MAP_SHARED) 7961da177e4SLinus Torvalds return -EINVAL; 7971da177e4SLinus Torvalds 798f81cff0dSMike Frysinger if (!len) 7991da177e4SLinus Torvalds return -EINVAL; 8001da177e4SLinus Torvalds 801f81cff0dSMike Frysinger /* Careful about overflows.. */ 8028feae131SDavid Howells rlen = PAGE_ALIGN(len); 8038feae131SDavid Howells if (!rlen || rlen > TASK_SIZE) 804f81cff0dSMike Frysinger return -ENOMEM; 805f81cff0dSMike Frysinger 8061da177e4SLinus Torvalds /* offset overflow? */ 8078feae131SDavid Howells if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) 808f81cff0dSMike Frysinger return -EOVERFLOW; 8091da177e4SLinus Torvalds 8101da177e4SLinus Torvalds if (file) { 8111da177e4SLinus Torvalds /* files must support mmap */ 81272c2d531SAl Viro if (!file->f_op->mmap) 8131da177e4SLinus Torvalds return -ENODEV; 8141da177e4SLinus Torvalds 8151da177e4SLinus Torvalds /* work out if what we've got could possibly be shared 8161da177e4SLinus Torvalds * - we support chardevs that provide their own "memory" 8171da177e4SLinus Torvalds * - we support files/blockdevs that are memory backed 8181da177e4SLinus Torvalds */ 819b4caecd4SChristoph Hellwig if (file->f_op->mmap_capabilities) { 820b4caecd4SChristoph Hellwig capabilities = file->f_op->mmap_capabilities(file); 821b4caecd4SChristoph Hellwig } else { 8221da177e4SLinus Torvalds /* no explicit capabilities set, so assume some 8231da177e4SLinus Torvalds * defaults */ 824496ad9aaSAl Viro switch (file_inode(file)->i_mode & S_IFMT) { 8251da177e4SLinus Torvalds case S_IFREG: 8261da177e4SLinus Torvalds case S_IFBLK: 827b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 8281da177e4SLinus Torvalds break; 8291da177e4SLinus Torvalds 8301da177e4SLinus Torvalds case S_IFCHR: 8311da177e4SLinus Torvalds capabilities = 832b4caecd4SChristoph Hellwig NOMMU_MAP_DIRECT | 833b4caecd4SChristoph Hellwig NOMMU_MAP_READ | 834b4caecd4SChristoph Hellwig NOMMU_MAP_WRITE; 8351da177e4SLinus Torvalds break; 8361da177e4SLinus Torvalds 8371da177e4SLinus Torvalds default: 8381da177e4SLinus Torvalds return -EINVAL; 8391da177e4SLinus Torvalds } 8401da177e4SLinus Torvalds } 8411da177e4SLinus Torvalds 8421da177e4SLinus Torvalds /* eliminate any capabilities that we can't support on this 8431da177e4SLinus Torvalds * device */ 8441da177e4SLinus Torvalds if (!file->f_op->get_unmapped_area) 845b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8466e242a1cSAl Viro if (!(file->f_mode & FMODE_CAN_READ)) 847b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 8481da177e4SLinus Torvalds 84928d7a6aeSGraff Yang /* The file shall have been opened with read permission. */ 85028d7a6aeSGraff Yang if (!(file->f_mode & FMODE_READ)) 85128d7a6aeSGraff Yang return -EACCES; 85228d7a6aeSGraff Yang 8531da177e4SLinus Torvalds if (flags & MAP_SHARED) { 8541da177e4SLinus Torvalds /* do checks for writing, appending and locking */ 8551da177e4SLinus Torvalds if ((prot & PROT_WRITE) && 8561da177e4SLinus Torvalds !(file->f_mode & FMODE_WRITE)) 8571da177e4SLinus Torvalds return -EACCES; 8581da177e4SLinus Torvalds 859496ad9aaSAl Viro if (IS_APPEND(file_inode(file)) && 8601da177e4SLinus Torvalds (file->f_mode & FMODE_WRITE)) 8611da177e4SLinus Torvalds return -EACCES; 8621da177e4SLinus Torvalds 863d7a06983SJeff Layton if (locks_verify_locked(file)) 8641da177e4SLinus Torvalds return -EAGAIN; 8651da177e4SLinus Torvalds 866b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 8671da177e4SLinus Torvalds return -ENODEV; 8681da177e4SLinus Torvalds 8691da177e4SLinus Torvalds /* we mustn't privatise shared mappings */ 870b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_COPY; 871ac714904SChoi Gi-yong } else { 8721da177e4SLinus Torvalds /* we're going to read the file into private memory we 8731da177e4SLinus Torvalds * allocate */ 874b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 8751da177e4SLinus Torvalds return -ENODEV; 8761da177e4SLinus Torvalds 8771da177e4SLinus Torvalds /* we don't permit a private writable mapping to be 8781da177e4SLinus Torvalds * shared with the backing device */ 8791da177e4SLinus Torvalds if (prot & PROT_WRITE) 880b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8811da177e4SLinus Torvalds } 8821da177e4SLinus Torvalds 883b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 884b4caecd4SChristoph Hellwig if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) || 885b4caecd4SChristoph Hellwig ((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) || 886b4caecd4SChristoph Hellwig ((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC)) 8873c7b2045SBernd Schmidt ) { 888b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 8893c7b2045SBernd Schmidt if (flags & MAP_SHARED) { 89022cc877bSLeon Romanovsky pr_warn("MAP_SHARED not completely supported on !MMU\n"); 8913c7b2045SBernd Schmidt return -EINVAL; 8923c7b2045SBernd Schmidt } 8933c7b2045SBernd Schmidt } 8943c7b2045SBernd Schmidt } 8953c7b2045SBernd Schmidt 8961da177e4SLinus Torvalds /* handle executable mappings and implied executable 8971da177e4SLinus Torvalds * mappings */ 89890f8572bSEric W. Biederman if (path_noexec(&file->f_path)) { 8991da177e4SLinus Torvalds if (prot & PROT_EXEC) 9001da177e4SLinus Torvalds return -EPERM; 901ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { 9021da177e4SLinus Torvalds /* handle implication of PROT_EXEC by PROT_READ */ 9031da177e4SLinus Torvalds if (current->personality & READ_IMPLIES_EXEC) { 904b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_EXEC) 9051da177e4SLinus Torvalds prot |= PROT_EXEC; 9061da177e4SLinus Torvalds } 907ac714904SChoi Gi-yong } else if ((prot & PROT_READ) && 9081da177e4SLinus Torvalds (prot & PROT_EXEC) && 909b4caecd4SChristoph Hellwig !(capabilities & NOMMU_MAP_EXEC) 9101da177e4SLinus Torvalds ) { 9111da177e4SLinus Torvalds /* backing file is not executable, try to copy */ 912b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 9131da177e4SLinus Torvalds } 914ac714904SChoi Gi-yong } else { 9151da177e4SLinus Torvalds /* anonymous mappings are always memory backed and can be 9161da177e4SLinus Torvalds * privately mapped 9171da177e4SLinus Torvalds */ 918b4caecd4SChristoph Hellwig capabilities = NOMMU_MAP_COPY; 9191da177e4SLinus Torvalds 9201da177e4SLinus Torvalds /* handle PROT_EXEC implication by PROT_READ */ 9211da177e4SLinus Torvalds if ((prot & PROT_READ) && 9221da177e4SLinus Torvalds (current->personality & READ_IMPLIES_EXEC)) 9231da177e4SLinus Torvalds prot |= PROT_EXEC; 9241da177e4SLinus Torvalds } 9251da177e4SLinus Torvalds 9261da177e4SLinus Torvalds /* allow the security API to have its say */ 927e5467859SAl Viro ret = security_mmap_addr(addr); 928e5467859SAl Viro if (ret < 0) 929e5467859SAl Viro return ret; 9301da177e4SLinus Torvalds 9311da177e4SLinus Torvalds /* looks okay */ 9321da177e4SLinus Torvalds *_capabilities = capabilities; 9331da177e4SLinus Torvalds return 0; 9341da177e4SLinus Torvalds } 9351da177e4SLinus Torvalds 9361da177e4SLinus Torvalds /* 9371da177e4SLinus Torvalds * we've determined that we can make the mapping, now translate what we 9381da177e4SLinus Torvalds * now know into VMA flags 9391da177e4SLinus Torvalds */ 9401da177e4SLinus Torvalds static unsigned long determine_vm_flags(struct file *file, 9411da177e4SLinus Torvalds unsigned long prot, 9421da177e4SLinus Torvalds unsigned long flags, 9431da177e4SLinus Torvalds unsigned long capabilities) 9441da177e4SLinus Torvalds { 9451da177e4SLinus Torvalds unsigned long vm_flags; 9461da177e4SLinus Torvalds 947e6bfb709SDave Hansen vm_flags = calc_vm_prot_bits(prot, 0) | calc_vm_flag_bits(flags); 9481da177e4SLinus Torvalds /* vm_flags |= mm->def_flags; */ 9491da177e4SLinus Torvalds 950b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) { 9511da177e4SLinus Torvalds /* attempt to share read-only copies of mapped file chunks */ 9523c7b2045SBernd Schmidt vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; 9531da177e4SLinus Torvalds if (file && !(prot & PROT_WRITE)) 9541da177e4SLinus Torvalds vm_flags |= VM_MAYSHARE; 9553c7b2045SBernd Schmidt } else { 9561da177e4SLinus Torvalds /* overlay a shareable mapping on the backing device or inode 9571da177e4SLinus Torvalds * if possible - used for chardevs, ramfs/tmpfs/shmfs and 9581da177e4SLinus Torvalds * romfs/cramfs */ 959b4caecd4SChristoph Hellwig vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS); 9601da177e4SLinus Torvalds if (flags & MAP_SHARED) 9613c7b2045SBernd Schmidt vm_flags |= VM_SHARED; 9621da177e4SLinus Torvalds } 9631da177e4SLinus Torvalds 9641da177e4SLinus Torvalds /* refuse to let anyone share private mappings with this process if 9651da177e4SLinus Torvalds * it's being traced - otherwise breakpoints set in it may interfere 9661da177e4SLinus Torvalds * with another untraced process 9671da177e4SLinus Torvalds */ 968a288eeccSTejun Heo if ((flags & MAP_PRIVATE) && current->ptrace) 9691da177e4SLinus Torvalds vm_flags &= ~VM_MAYSHARE; 9701da177e4SLinus Torvalds 9711da177e4SLinus Torvalds return vm_flags; 9721da177e4SLinus Torvalds } 9731da177e4SLinus Torvalds 9741da177e4SLinus Torvalds /* 9758feae131SDavid Howells * set up a shared mapping on a file (the driver or filesystem provides and 9768feae131SDavid Howells * pins the storage) 9771da177e4SLinus Torvalds */ 9788feae131SDavid Howells static int do_mmap_shared_file(struct vm_area_struct *vma) 9791da177e4SLinus Torvalds { 9801da177e4SLinus Torvalds int ret; 9811da177e4SLinus Torvalds 982f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 983dd8632a1SPaul Mundt if (ret == 0) { 984dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 985645d83c5SDavid Howells return 0; 986dd8632a1SPaul Mundt } 9871da177e4SLinus Torvalds if (ret != -ENOSYS) 9881da177e4SLinus Torvalds return ret; 9891da177e4SLinus Torvalds 9903fa30460SDavid Howells /* getting -ENOSYS indicates that direct mmap isn't possible (as 9913fa30460SDavid Howells * opposed to tried but failed) so we can only give a suitable error as 9923fa30460SDavid Howells * it's not possible to make a private copy if MAP_SHARED was given */ 9931da177e4SLinus Torvalds return -ENODEV; 9941da177e4SLinus Torvalds } 9951da177e4SLinus Torvalds 9961da177e4SLinus Torvalds /* 9971da177e4SLinus Torvalds * set up a private mapping or an anonymous shared mapping 9981da177e4SLinus Torvalds */ 9998feae131SDavid Howells static int do_mmap_private(struct vm_area_struct *vma, 10008feae131SDavid Howells struct vm_region *region, 1001645d83c5SDavid Howells unsigned long len, 1002645d83c5SDavid Howells unsigned long capabilities) 10031da177e4SLinus Torvalds { 1004dbc8358cSJoonsoo Kim unsigned long total, point; 10051da177e4SLinus Torvalds void *base; 10068feae131SDavid Howells int ret, order; 10071da177e4SLinus Torvalds 10081da177e4SLinus Torvalds /* invoke the file's mapping function so that it can keep track of 10091da177e4SLinus Torvalds * shared mappings on devices or memory 10101da177e4SLinus Torvalds * - VM_MAYSHARE will be set if it may attempt to share 10111da177e4SLinus Torvalds */ 1012b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 1013f74ac015SMiklos Szeredi ret = call_mmap(vma->vm_file, vma); 1014dd8632a1SPaul Mundt if (ret == 0) { 10151da177e4SLinus Torvalds /* shouldn't return success if we're not sharing */ 1016dd8632a1SPaul Mundt BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); 1017dd8632a1SPaul Mundt vma->vm_region->vm_top = vma->vm_region->vm_end; 1018645d83c5SDavid Howells return 0; 10191da177e4SLinus Torvalds } 1020dd8632a1SPaul Mundt if (ret != -ENOSYS) 1021dd8632a1SPaul Mundt return ret; 10221da177e4SLinus Torvalds 10231da177e4SLinus Torvalds /* getting an ENOSYS error indicates that direct mmap isn't 10241da177e4SLinus Torvalds * possible (as opposed to tried but failed) so we'll try to 10251da177e4SLinus Torvalds * make a private copy of the data and map that instead */ 10261da177e4SLinus Torvalds } 10271da177e4SLinus Torvalds 10288feae131SDavid Howells 10291da177e4SLinus Torvalds /* allocate some memory to hold the mapping 10301da177e4SLinus Torvalds * - note that this may not return a page-aligned address if the object 10311da177e4SLinus Torvalds * we're allocating is smaller than a page 10321da177e4SLinus Torvalds */ 1033f67d9b15SBob Liu order = get_order(len); 10348feae131SDavid Howells total = 1 << order; 1035f67d9b15SBob Liu point = len >> PAGE_SHIFT; 1036dd8632a1SPaul Mundt 1037dbc8358cSJoonsoo Kim /* we don't want to allocate a power-of-2 sized page set */ 103822cc877bSLeon Romanovsky if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) 1039dbc8358cSJoonsoo Kim total = point; 10408feae131SDavid Howells 1041da616534SJoonsoo Kim base = alloc_pages_exact(total << PAGE_SHIFT, GFP_KERNEL); 1042dbc8358cSJoonsoo Kim if (!base) 1043dbc8358cSJoonsoo Kim goto enomem; 10448feae131SDavid Howells 1045dbc8358cSJoonsoo Kim atomic_long_add(total, &mmap_pages_allocated); 1046dbc8358cSJoonsoo Kim 10478feae131SDavid Howells region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; 10488feae131SDavid Howells region->vm_start = (unsigned long) base; 1049f67d9b15SBob Liu region->vm_end = region->vm_start + len; 1050dd8632a1SPaul Mundt region->vm_top = region->vm_start + (total << PAGE_SHIFT); 10518feae131SDavid Howells 10528feae131SDavid Howells vma->vm_start = region->vm_start; 10538feae131SDavid Howells vma->vm_end = region->vm_start + len; 10541da177e4SLinus Torvalds 10551da177e4SLinus Torvalds if (vma->vm_file) { 10561da177e4SLinus Torvalds /* read the contents of a file into the copy */ 10571da177e4SLinus Torvalds loff_t fpos; 10581da177e4SLinus Torvalds 10591da177e4SLinus Torvalds fpos = vma->vm_pgoff; 10601da177e4SLinus Torvalds fpos <<= PAGE_SHIFT; 10611da177e4SLinus Torvalds 1062b4bf802aSChristoph Hellwig ret = kernel_read(vma->vm_file, base, len, &fpos); 10631da177e4SLinus Torvalds if (ret < 0) 10641da177e4SLinus Torvalds goto error_free; 10651da177e4SLinus Torvalds 10661da177e4SLinus Torvalds /* clear the last little bit */ 1067f67d9b15SBob Liu if (ret < len) 1068f67d9b15SBob Liu memset(base + ret, 0, len - ret); 10691da177e4SLinus Torvalds 1070bfd40eafSKirill A. Shutemov } else { 1071bfd40eafSKirill A. Shutemov vma_set_anonymous(vma); 10721da177e4SLinus Torvalds } 10731da177e4SLinus Torvalds 10741da177e4SLinus Torvalds return 0; 10751da177e4SLinus Torvalds 10761da177e4SLinus Torvalds error_free: 10777223bb4aSNamhyung Kim free_page_series(region->vm_start, region->vm_top); 10788feae131SDavid Howells region->vm_start = vma->vm_start = 0; 10798feae131SDavid Howells region->vm_end = vma->vm_end = 0; 1080dd8632a1SPaul Mundt region->vm_top = 0; 10811da177e4SLinus Torvalds return ret; 10821da177e4SLinus Torvalds 10831da177e4SLinus Torvalds enomem: 1084b1de0d13SMitchel Humpherys pr_err("Allocation of length %lu from process %d (%s) failed\n", 108505ae6fa3SGreg Ungerer len, current->pid, current->comm); 10869af744d7SMichal Hocko show_free_areas(0, NULL); 10871da177e4SLinus Torvalds return -ENOMEM; 10881da177e4SLinus Torvalds } 10891da177e4SLinus Torvalds 10901da177e4SLinus Torvalds /* 10911da177e4SLinus Torvalds * handle mapping creation for uClinux 10921da177e4SLinus Torvalds */ 10931fcfd8dbSOleg Nesterov unsigned long do_mmap(struct file *file, 10941da177e4SLinus Torvalds unsigned long addr, 10951da177e4SLinus Torvalds unsigned long len, 10961da177e4SLinus Torvalds unsigned long prot, 10971da177e4SLinus Torvalds unsigned long flags, 10981fcfd8dbSOleg Nesterov vm_flags_t vm_flags, 1099bebeb3d6SMichel Lespinasse unsigned long pgoff, 1100897ab3e0SMike Rapoport unsigned long *populate, 1101897ab3e0SMike Rapoport struct list_head *uf) 11021da177e4SLinus Torvalds { 11038feae131SDavid Howells struct vm_area_struct *vma; 11048feae131SDavid Howells struct vm_region *region; 11051da177e4SLinus Torvalds struct rb_node *rb; 11061fcfd8dbSOleg Nesterov unsigned long capabilities, result; 11071da177e4SLinus Torvalds int ret; 11081da177e4SLinus Torvalds 110941badc15SMichel Lespinasse *populate = 0; 1110bebeb3d6SMichel Lespinasse 11111da177e4SLinus Torvalds /* decide whether we should attempt the mapping, and if so what sort of 11121da177e4SLinus Torvalds * mapping */ 11131da177e4SLinus Torvalds ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, 11141da177e4SLinus Torvalds &capabilities); 111522cc877bSLeon Romanovsky if (ret < 0) 11161da177e4SLinus Torvalds return ret; 11171da177e4SLinus Torvalds 111806aab5a3SDavid Howells /* we ignore the address hint */ 111906aab5a3SDavid Howells addr = 0; 1120f67d9b15SBob Liu len = PAGE_ALIGN(len); 112106aab5a3SDavid Howells 11221da177e4SLinus Torvalds /* we've determined that we can make the mapping, now translate what we 11231da177e4SLinus Torvalds * now know into VMA flags */ 11241fcfd8dbSOleg Nesterov vm_flags |= determine_vm_flags(file, prot, flags, capabilities); 11251da177e4SLinus Torvalds 11268feae131SDavid Howells /* we're going to need to record the mapping */ 11278feae131SDavid Howells region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); 11288feae131SDavid Howells if (!region) 11298feae131SDavid Howells goto error_getting_region; 11301da177e4SLinus Torvalds 1131490fc053SLinus Torvalds vma = vm_area_alloc(current->mm); 11328feae131SDavid Howells if (!vma) 11338feae131SDavid Howells goto error_getting_vma; 11341da177e4SLinus Torvalds 11351e2ae599SDavid Howells region->vm_usage = 1; 11368feae131SDavid Howells region->vm_flags = vm_flags; 11378feae131SDavid Howells region->vm_pgoff = pgoff; 11388feae131SDavid Howells 11398feae131SDavid Howells vma->vm_flags = vm_flags; 11408feae131SDavid Howells vma->vm_pgoff = pgoff; 11418feae131SDavid Howells 11428feae131SDavid Howells if (file) { 1143cb0942b8SAl Viro region->vm_file = get_file(file); 1144cb0942b8SAl Viro vma->vm_file = get_file(file); 11458feae131SDavid Howells } 11468feae131SDavid Howells 11478feae131SDavid Howells down_write(&nommu_region_sem); 11488feae131SDavid Howells 11498feae131SDavid Howells /* if we want to share, we need to check for regions created by other 11501da177e4SLinus Torvalds * mmap() calls that overlap with our proposed mapping 11518feae131SDavid Howells * - we can only share with a superset match on most regular files 11521da177e4SLinus Torvalds * - shared mappings on character devices and memory backed files are 11531da177e4SLinus Torvalds * permitted to overlap inexactly as far as we are concerned for in 11541da177e4SLinus Torvalds * these cases, sharing is handled in the driver or filesystem rather 11551da177e4SLinus Torvalds * than here 11561da177e4SLinus Torvalds */ 11571da177e4SLinus Torvalds if (vm_flags & VM_MAYSHARE) { 11588feae131SDavid Howells struct vm_region *pregion; 11598feae131SDavid Howells unsigned long pglen, rpglen, pgend, rpgend, start; 11601da177e4SLinus Torvalds 11618feae131SDavid Howells pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; 11628feae131SDavid Howells pgend = pgoff + pglen; 1163165b2392SDavid Howells 11648feae131SDavid Howells for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { 11658feae131SDavid Howells pregion = rb_entry(rb, struct vm_region, vm_rb); 11661da177e4SLinus Torvalds 11678feae131SDavid Howells if (!(pregion->vm_flags & VM_MAYSHARE)) 11681da177e4SLinus Torvalds continue; 11691da177e4SLinus Torvalds 11701da177e4SLinus Torvalds /* search for overlapping mappings on the same file */ 1171496ad9aaSAl Viro if (file_inode(pregion->vm_file) != 1172496ad9aaSAl Viro file_inode(file)) 11731da177e4SLinus Torvalds continue; 11741da177e4SLinus Torvalds 11758feae131SDavid Howells if (pregion->vm_pgoff >= pgend) 11761da177e4SLinus Torvalds continue; 11771da177e4SLinus Torvalds 11788feae131SDavid Howells rpglen = pregion->vm_end - pregion->vm_start; 11798feae131SDavid Howells rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; 11808feae131SDavid Howells rpgend = pregion->vm_pgoff + rpglen; 11818feae131SDavid Howells if (pgoff >= rpgend) 11821da177e4SLinus Torvalds continue; 11831da177e4SLinus Torvalds 11848feae131SDavid Howells /* handle inexactly overlapping matches between 11858feae131SDavid Howells * mappings */ 11868feae131SDavid Howells if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && 11878feae131SDavid Howells !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { 11888feae131SDavid Howells /* new mapping is not a subset of the region */ 1189b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_DIRECT)) 11901da177e4SLinus Torvalds goto sharing_violation; 11911da177e4SLinus Torvalds continue; 11921da177e4SLinus Torvalds } 11931da177e4SLinus Torvalds 11948feae131SDavid Howells /* we've found a region we can share */ 11951e2ae599SDavid Howells pregion->vm_usage++; 11968feae131SDavid Howells vma->vm_region = pregion; 11978feae131SDavid Howells start = pregion->vm_start; 11988feae131SDavid Howells start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; 11998feae131SDavid Howells vma->vm_start = start; 12008feae131SDavid Howells vma->vm_end = start + len; 12011da177e4SLinus Torvalds 120222cc877bSLeon Romanovsky if (pregion->vm_flags & VM_MAPPED_COPY) 12038feae131SDavid Howells vma->vm_flags |= VM_MAPPED_COPY; 120422cc877bSLeon Romanovsky else { 12058feae131SDavid Howells ret = do_mmap_shared_file(vma); 12068feae131SDavid Howells if (ret < 0) { 12078feae131SDavid Howells vma->vm_region = NULL; 12088feae131SDavid Howells vma->vm_start = 0; 12098feae131SDavid Howells vma->vm_end = 0; 12101e2ae599SDavid Howells pregion->vm_usage--; 12118feae131SDavid Howells pregion = NULL; 12128feae131SDavid Howells goto error_just_free; 12131da177e4SLinus Torvalds } 12148feae131SDavid Howells } 12158feae131SDavid Howells fput(region->vm_file); 12168feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 12178feae131SDavid Howells region = pregion; 12188feae131SDavid Howells result = start; 12198feae131SDavid Howells goto share; 12208feae131SDavid Howells } 12211da177e4SLinus Torvalds 12221da177e4SLinus Torvalds /* obtain the address at which to make a shared mapping 12231da177e4SLinus Torvalds * - this is the hook for quasi-memory character devices to 12241da177e4SLinus Torvalds * tell us the location of a shared mapping 12251da177e4SLinus Torvalds */ 1226b4caecd4SChristoph Hellwig if (capabilities & NOMMU_MAP_DIRECT) { 12271da177e4SLinus Torvalds addr = file->f_op->get_unmapped_area(file, addr, len, 12281da177e4SLinus Torvalds pgoff, flags); 1229bb005a59SNamhyung Kim if (IS_ERR_VALUE(addr)) { 12301da177e4SLinus Torvalds ret = addr; 1231bb005a59SNamhyung Kim if (ret != -ENOSYS) 12328feae131SDavid Howells goto error_just_free; 12331da177e4SLinus Torvalds 12341da177e4SLinus Torvalds /* the driver refused to tell us where to site 12351da177e4SLinus Torvalds * the mapping so we'll have to attempt to copy 12361da177e4SLinus Torvalds * it */ 1237bb005a59SNamhyung Kim ret = -ENODEV; 1238b4caecd4SChristoph Hellwig if (!(capabilities & NOMMU_MAP_COPY)) 12398feae131SDavid Howells goto error_just_free; 12401da177e4SLinus Torvalds 1241b4caecd4SChristoph Hellwig capabilities &= ~NOMMU_MAP_DIRECT; 12428feae131SDavid Howells } else { 12438feae131SDavid Howells vma->vm_start = region->vm_start = addr; 12448feae131SDavid Howells vma->vm_end = region->vm_end = addr + len; 12451da177e4SLinus Torvalds } 12461da177e4SLinus Torvalds } 12471da177e4SLinus Torvalds } 12481da177e4SLinus Torvalds 12498feae131SDavid Howells vma->vm_region = region; 12501da177e4SLinus Torvalds 1251645d83c5SDavid Howells /* set up the mapping 1252b4caecd4SChristoph Hellwig * - the region is filled in if NOMMU_MAP_DIRECT is still set 1253645d83c5SDavid Howells */ 12541da177e4SLinus Torvalds if (file && vma->vm_flags & VM_SHARED) 12558feae131SDavid Howells ret = do_mmap_shared_file(vma); 12561da177e4SLinus Torvalds else 1257645d83c5SDavid Howells ret = do_mmap_private(vma, region, len, capabilities); 12581da177e4SLinus Torvalds if (ret < 0) 1259645d83c5SDavid Howells goto error_just_free; 1260645d83c5SDavid Howells add_nommu_region(region); 12618feae131SDavid Howells 1262ea637639SJie Zhang /* clear anonymous mappings that don't ask for uninitialized data */ 12630bf5f949SChristoph Hellwig if (!vma->vm_file && 12640bf5f949SChristoph Hellwig (!IS_ENABLED(CONFIG_MMAP_ALLOW_UNINITIALIZED) || 12650bf5f949SChristoph Hellwig !(flags & MAP_UNINITIALIZED))) 1266ea637639SJie Zhang memset((void *)region->vm_start, 0, 1267ea637639SJie Zhang region->vm_end - region->vm_start); 1268ea637639SJie Zhang 12691da177e4SLinus Torvalds /* okay... we have a mapping; now we have to register it */ 12708feae131SDavid Howells result = vma->vm_start; 12711da177e4SLinus Torvalds 12721da177e4SLinus Torvalds current->mm->total_vm += len >> PAGE_SHIFT; 12731da177e4SLinus Torvalds 12748feae131SDavid Howells share: 12758feae131SDavid Howells add_vma_to_mm(current->mm, vma); 12761da177e4SLinus Torvalds 1277cfe79c00SMike Frysinger /* we flush the region from the icache only when the first executable 1278cfe79c00SMike Frysinger * mapping of it is made */ 1279cfe79c00SMike Frysinger if (vma->vm_flags & VM_EXEC && !region->vm_icache_flushed) { 1280a75a2df6SChristoph Hellwig flush_icache_user_range(region->vm_start, region->vm_end); 1281cfe79c00SMike Frysinger region->vm_icache_flushed = true; 1282cfe79c00SMike Frysinger } 12831da177e4SLinus Torvalds 1284cfe79c00SMike Frysinger up_write(&nommu_region_sem); 12851da177e4SLinus Torvalds 12868feae131SDavid Howells return result; 12871da177e4SLinus Torvalds 12888feae131SDavid Howells error_just_free: 12898feae131SDavid Howells up_write(&nommu_region_sem); 12908feae131SDavid Howells error: 129189a86402SDavid Howells if (region->vm_file) 12928feae131SDavid Howells fput(region->vm_file); 12938feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 129489a86402SDavid Howells if (vma->vm_file) 12958feae131SDavid Howells fput(vma->vm_file); 12963928d4f5SLinus Torvalds vm_area_free(vma); 12971da177e4SLinus Torvalds return ret; 12981da177e4SLinus Torvalds 12991da177e4SLinus Torvalds sharing_violation: 13008feae131SDavid Howells up_write(&nommu_region_sem); 130122cc877bSLeon Romanovsky pr_warn("Attempt to share mismatched mappings\n"); 13028feae131SDavid Howells ret = -EINVAL; 13038feae131SDavid Howells goto error; 13041da177e4SLinus Torvalds 13051da177e4SLinus Torvalds error_getting_vma: 13068feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 130722cc877bSLeon Romanovsky pr_warn("Allocation of vma for %lu byte allocation from process %d failed\n", 13081da177e4SLinus Torvalds len, current->pid); 13099af744d7SMichal Hocko show_free_areas(0, NULL); 13101da177e4SLinus Torvalds return -ENOMEM; 13111da177e4SLinus Torvalds 13128feae131SDavid Howells error_getting_region: 131322cc877bSLeon Romanovsky pr_warn("Allocation of vm region for %lu byte allocation from process %d failed\n", 13141da177e4SLinus Torvalds len, current->pid); 13159af744d7SMichal Hocko show_free_areas(0, NULL); 13161da177e4SLinus Torvalds return -ENOMEM; 13171da177e4SLinus Torvalds } 13186be5ceb0SLinus Torvalds 1319a90f590aSDominik Brodowski unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, 1320a90f590aSDominik Brodowski unsigned long prot, unsigned long flags, 1321a90f590aSDominik Brodowski unsigned long fd, unsigned long pgoff) 132266f0dc48SHugh Dickins { 132366f0dc48SHugh Dickins struct file *file = NULL; 132466f0dc48SHugh Dickins unsigned long retval = -EBADF; 132566f0dc48SHugh Dickins 1326120a795dSAl Viro audit_mmap_fd(fd, flags); 132766f0dc48SHugh Dickins if (!(flags & MAP_ANONYMOUS)) { 132866f0dc48SHugh Dickins file = fget(fd); 132966f0dc48SHugh Dickins if (!file) 133066f0dc48SHugh Dickins goto out; 133166f0dc48SHugh Dickins } 133266f0dc48SHugh Dickins 133366f0dc48SHugh Dickins flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); 133466f0dc48SHugh Dickins 1335ad1ed293SGreg Ungerer retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); 133666f0dc48SHugh Dickins 133766f0dc48SHugh Dickins if (file) 133866f0dc48SHugh Dickins fput(file); 133966f0dc48SHugh Dickins out: 134066f0dc48SHugh Dickins return retval; 134166f0dc48SHugh Dickins } 134266f0dc48SHugh Dickins 1343a90f590aSDominik Brodowski SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, 1344a90f590aSDominik Brodowski unsigned long, prot, unsigned long, flags, 1345a90f590aSDominik Brodowski unsigned long, fd, unsigned long, pgoff) 1346a90f590aSDominik Brodowski { 1347a90f590aSDominik Brodowski return ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); 1348a90f590aSDominik Brodowski } 1349a90f590aSDominik Brodowski 1350a4679373SChristoph Hellwig #ifdef __ARCH_WANT_SYS_OLD_MMAP 1351a4679373SChristoph Hellwig struct mmap_arg_struct { 1352a4679373SChristoph Hellwig unsigned long addr; 1353a4679373SChristoph Hellwig unsigned long len; 1354a4679373SChristoph Hellwig unsigned long prot; 1355a4679373SChristoph Hellwig unsigned long flags; 1356a4679373SChristoph Hellwig unsigned long fd; 1357a4679373SChristoph Hellwig unsigned long offset; 1358a4679373SChristoph Hellwig }; 1359a4679373SChristoph Hellwig 1360a4679373SChristoph Hellwig SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) 1361a4679373SChristoph Hellwig { 1362a4679373SChristoph Hellwig struct mmap_arg_struct a; 1363a4679373SChristoph Hellwig 1364a4679373SChristoph Hellwig if (copy_from_user(&a, arg, sizeof(a))) 1365a4679373SChristoph Hellwig return -EFAULT; 13661824cb75SAlexander Kuleshov if (offset_in_page(a.offset)) 1367a4679373SChristoph Hellwig return -EINVAL; 1368a4679373SChristoph Hellwig 1369a90f590aSDominik Brodowski return ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, 1370a4679373SChristoph Hellwig a.offset >> PAGE_SHIFT); 1371a4679373SChristoph Hellwig } 1372a4679373SChristoph Hellwig #endif /* __ARCH_WANT_SYS_OLD_MMAP */ 1373a4679373SChristoph Hellwig 13741da177e4SLinus Torvalds /* 13758feae131SDavid Howells * split a vma into two pieces at address 'addr', a new vma is allocated either 13768feae131SDavid Howells * for the first part or the tail. 13771da177e4SLinus Torvalds */ 13788feae131SDavid Howells int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, 13798feae131SDavid Howells unsigned long addr, int new_below) 13801da177e4SLinus Torvalds { 13818feae131SDavid Howells struct vm_area_struct *new; 13828feae131SDavid Howells struct vm_region *region; 13838feae131SDavid Howells unsigned long npages; 13841da177e4SLinus Torvalds 1385779c1023SDavid Howells /* we're only permitted to split anonymous regions (these should have 1386779c1023SDavid Howells * only a single usage on the region) */ 1387779c1023SDavid Howells if (vma->vm_file) 13888feae131SDavid Howells return -ENOMEM; 13891da177e4SLinus Torvalds 13908feae131SDavid Howells if (mm->map_count >= sysctl_max_map_count) 13918feae131SDavid Howells return -ENOMEM; 13921da177e4SLinus Torvalds 13938feae131SDavid Howells region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); 13948feae131SDavid Howells if (!region) 13958feae131SDavid Howells return -ENOMEM; 13968feae131SDavid Howells 13973928d4f5SLinus Torvalds new = vm_area_dup(vma); 13988feae131SDavid Howells if (!new) { 13998feae131SDavid Howells kmem_cache_free(vm_region_jar, region); 14008feae131SDavid Howells return -ENOMEM; 14011da177e4SLinus Torvalds } 14021da177e4SLinus Torvalds 14038feae131SDavid Howells /* most fields are the same, copy all, and then fixup */ 14048feae131SDavid Howells *region = *vma->vm_region; 14058feae131SDavid Howells new->vm_region = region; 14068feae131SDavid Howells 14078feae131SDavid Howells npages = (addr - vma->vm_start) >> PAGE_SHIFT; 14088feae131SDavid Howells 14098feae131SDavid Howells if (new_below) { 1410dd8632a1SPaul Mundt region->vm_top = region->vm_end = new->vm_end = addr; 14118feae131SDavid Howells } else { 14128feae131SDavid Howells region->vm_start = new->vm_start = addr; 14138feae131SDavid Howells region->vm_pgoff = new->vm_pgoff += npages; 14141da177e4SLinus Torvalds } 14158feae131SDavid Howells 14168feae131SDavid Howells if (new->vm_ops && new->vm_ops->open) 14178feae131SDavid Howells new->vm_ops->open(new); 14188feae131SDavid Howells 14198feae131SDavid Howells delete_vma_from_mm(vma); 14208feae131SDavid Howells down_write(&nommu_region_sem); 14218feae131SDavid Howells delete_nommu_region(vma->vm_region); 14228feae131SDavid Howells if (new_below) { 14238feae131SDavid Howells vma->vm_region->vm_start = vma->vm_start = addr; 14248feae131SDavid Howells vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; 14258feae131SDavid Howells } else { 14268feae131SDavid Howells vma->vm_region->vm_end = vma->vm_end = addr; 1427dd8632a1SPaul Mundt vma->vm_region->vm_top = addr; 14288feae131SDavid Howells } 14298feae131SDavid Howells add_nommu_region(vma->vm_region); 14308feae131SDavid Howells add_nommu_region(new->vm_region); 14318feae131SDavid Howells up_write(&nommu_region_sem); 14328feae131SDavid Howells add_vma_to_mm(mm, vma); 14338feae131SDavid Howells add_vma_to_mm(mm, new); 14348feae131SDavid Howells return 0; 14358feae131SDavid Howells } 14368feae131SDavid Howells 14378feae131SDavid Howells /* 14388feae131SDavid Howells * shrink a VMA by removing the specified chunk from either the beginning or 14398feae131SDavid Howells * the end 14408feae131SDavid Howells */ 14418feae131SDavid Howells static int shrink_vma(struct mm_struct *mm, 14428feae131SDavid Howells struct vm_area_struct *vma, 14438feae131SDavid Howells unsigned long from, unsigned long to) 14448feae131SDavid Howells { 14458feae131SDavid Howells struct vm_region *region; 14468feae131SDavid Howells 14478feae131SDavid Howells /* adjust the VMA's pointers, which may reposition it in the MM's tree 14488feae131SDavid Howells * and list */ 14498feae131SDavid Howells delete_vma_from_mm(vma); 14508feae131SDavid Howells if (from > vma->vm_start) 14518feae131SDavid Howells vma->vm_end = from; 14528feae131SDavid Howells else 14538feae131SDavid Howells vma->vm_start = to; 14548feae131SDavid Howells add_vma_to_mm(mm, vma); 14558feae131SDavid Howells 14568feae131SDavid Howells /* cut the backing region down to size */ 14578feae131SDavid Howells region = vma->vm_region; 14581e2ae599SDavid Howells BUG_ON(region->vm_usage != 1); 14598feae131SDavid Howells 14608feae131SDavid Howells down_write(&nommu_region_sem); 14618feae131SDavid Howells delete_nommu_region(region); 1462dd8632a1SPaul Mundt if (from > region->vm_start) { 1463dd8632a1SPaul Mundt to = region->vm_top; 1464dd8632a1SPaul Mundt region->vm_top = region->vm_end = from; 1465dd8632a1SPaul Mundt } else { 14668feae131SDavid Howells region->vm_start = to; 1467dd8632a1SPaul Mundt } 14688feae131SDavid Howells add_nommu_region(region); 14698feae131SDavid Howells up_write(&nommu_region_sem); 14708feae131SDavid Howells 14718feae131SDavid Howells free_page_series(from, to); 14728feae131SDavid Howells return 0; 14731da177e4SLinus Torvalds } 14741da177e4SLinus Torvalds 14753034097aSDavid Howells /* 14763034097aSDavid Howells * release a mapping 14778feae131SDavid Howells * - under NOMMU conditions the chunk to be unmapped must be backed by a single 14788feae131SDavid Howells * VMA, though it need not cover the whole VMA 14793034097aSDavid Howells */ 1480897ab3e0SMike Rapoport int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list_head *uf) 14811da177e4SLinus Torvalds { 14828feae131SDavid Howells struct vm_area_struct *vma; 1483f67d9b15SBob Liu unsigned long end; 14848feae131SDavid Howells int ret; 14851da177e4SLinus Torvalds 1486f67d9b15SBob Liu len = PAGE_ALIGN(len); 14878feae131SDavid Howells if (len == 0) 14881da177e4SLinus Torvalds return -EINVAL; 14891da177e4SLinus Torvalds 1490f67d9b15SBob Liu end = start + len; 1491f67d9b15SBob Liu 14928feae131SDavid Howells /* find the first potentially overlapping VMA */ 14938feae131SDavid Howells vma = find_vma(mm, start); 14948feae131SDavid Howells if (!vma) { 1495ac714904SChoi Gi-yong static int limit; 149633e5d769SDavid Howells if (limit < 5) { 149722cc877bSLeon Romanovsky pr_warn("munmap of memory not mmapped by process %d (%s): 0x%lx-0x%lx\n", 149833e5d769SDavid Howells current->pid, current->comm, 149933e5d769SDavid Howells start, start + len - 1); 150033e5d769SDavid Howells limit++; 150133e5d769SDavid Howells } 15028feae131SDavid Howells return -EINVAL; 15038feae131SDavid Howells } 15041da177e4SLinus Torvalds 15058feae131SDavid Howells /* we're allowed to split an anonymous VMA but not a file-backed one */ 15068feae131SDavid Howells if (vma->vm_file) { 15078feae131SDavid Howells do { 150822cc877bSLeon Romanovsky if (start > vma->vm_start) 15098feae131SDavid Howells return -EINVAL; 15108feae131SDavid Howells if (end == vma->vm_end) 15118feae131SDavid Howells goto erase_whole_vma; 1512d75a310cSNamhyung Kim vma = vma->vm_next; 1513d75a310cSNamhyung Kim } while (vma); 15148feae131SDavid Howells return -EINVAL; 15158feae131SDavid Howells } else { 15168feae131SDavid Howells /* the chunk must be a subset of the VMA found */ 15178feae131SDavid Howells if (start == vma->vm_start && end == vma->vm_end) 15188feae131SDavid Howells goto erase_whole_vma; 151922cc877bSLeon Romanovsky if (start < vma->vm_start || end > vma->vm_end) 15208feae131SDavid Howells return -EINVAL; 15211824cb75SAlexander Kuleshov if (offset_in_page(start)) 15228feae131SDavid Howells return -EINVAL; 15231824cb75SAlexander Kuleshov if (end != vma->vm_end && offset_in_page(end)) 15248feae131SDavid Howells return -EINVAL; 15258feae131SDavid Howells if (start != vma->vm_start && end != vma->vm_end) { 15268feae131SDavid Howells ret = split_vma(mm, vma, start, 1); 152722cc877bSLeon Romanovsky if (ret < 0) 15288feae131SDavid Howells return ret; 15298feae131SDavid Howells } 15308feae131SDavid Howells return shrink_vma(mm, vma, start, end); 15318feae131SDavid Howells } 15321da177e4SLinus Torvalds 15338feae131SDavid Howells erase_whole_vma: 15348feae131SDavid Howells delete_vma_from_mm(vma); 15358feae131SDavid Howells delete_vma(mm, vma); 15361da177e4SLinus Torvalds return 0; 15371da177e4SLinus Torvalds } 1538b5073173SPaul Mundt EXPORT_SYMBOL(do_munmap); 15391da177e4SLinus Torvalds 1540bfce281cSAl Viro int vm_munmap(unsigned long addr, size_t len) 15413034097aSDavid Howells { 1542bfce281cSAl Viro struct mm_struct *mm = current->mm; 15433034097aSDavid Howells int ret; 15443034097aSDavid Howells 1545*d8ed45c5SMichel Lespinasse mmap_write_lock(mm); 1546897ab3e0SMike Rapoport ret = do_munmap(mm, addr, len, NULL); 1547*d8ed45c5SMichel Lespinasse mmap_write_unlock(mm); 15483034097aSDavid Howells return ret; 15493034097aSDavid Howells } 1550a46ef99dSLinus Torvalds EXPORT_SYMBOL(vm_munmap); 1551a46ef99dSLinus Torvalds 1552a46ef99dSLinus Torvalds SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) 1553a46ef99dSLinus Torvalds { 1554bfce281cSAl Viro return vm_munmap(addr, len); 1555a46ef99dSLinus Torvalds } 15563034097aSDavid Howells 15573034097aSDavid Howells /* 15588feae131SDavid Howells * release all the mappings made in a process's VM space 15593034097aSDavid Howells */ 15601da177e4SLinus Torvalds void exit_mmap(struct mm_struct *mm) 15611da177e4SLinus Torvalds { 15628feae131SDavid Howells struct vm_area_struct *vma; 15631da177e4SLinus Torvalds 15648feae131SDavid Howells if (!mm) 15658feae131SDavid Howells return; 15668feae131SDavid Howells 15671da177e4SLinus Torvalds mm->total_vm = 0; 15681da177e4SLinus Torvalds 15698feae131SDavid Howells while ((vma = mm->mmap)) { 15708feae131SDavid Howells mm->mmap = vma->vm_next; 15718feae131SDavid Howells delete_vma_from_mm(vma); 15728feae131SDavid Howells delete_vma(mm, vma); 157304c34961SSteven J. Magnani cond_resched(); 15741da177e4SLinus Torvalds } 15751da177e4SLinus Torvalds } 15761da177e4SLinus Torvalds 15775d22fc25SLinus Torvalds int vm_brk(unsigned long addr, unsigned long len) 15781da177e4SLinus Torvalds { 15791da177e4SLinus Torvalds return -ENOMEM; 15801da177e4SLinus Torvalds } 15811da177e4SLinus Torvalds 15821da177e4SLinus Torvalds /* 15836fa5f80bSDavid Howells * expand (or shrink) an existing mapping, potentially moving it at the same 15846fa5f80bSDavid Howells * time (controlled by the MREMAP_MAYMOVE flag and available VM space) 15851da177e4SLinus Torvalds * 15866fa5f80bSDavid Howells * under NOMMU conditions, we only permit changing a mapping's size, and only 15878feae131SDavid Howells * as long as it stays within the region allocated by do_mmap_private() and the 15888feae131SDavid Howells * block is not shareable 15891da177e4SLinus Torvalds * 15906fa5f80bSDavid Howells * MREMAP_FIXED is not supported under NOMMU conditions 15911da177e4SLinus Torvalds */ 15924b377babSAl Viro static unsigned long do_mremap(unsigned long addr, 15931da177e4SLinus Torvalds unsigned long old_len, unsigned long new_len, 15941da177e4SLinus Torvalds unsigned long flags, unsigned long new_addr) 15951da177e4SLinus Torvalds { 15966fa5f80bSDavid Howells struct vm_area_struct *vma; 15971da177e4SLinus Torvalds 15981da177e4SLinus Torvalds /* insanity checks first */ 1599f67d9b15SBob Liu old_len = PAGE_ALIGN(old_len); 1600f67d9b15SBob Liu new_len = PAGE_ALIGN(new_len); 16018feae131SDavid Howells if (old_len == 0 || new_len == 0) 16021da177e4SLinus Torvalds return (unsigned long) -EINVAL; 16031da177e4SLinus Torvalds 16041824cb75SAlexander Kuleshov if (offset_in_page(addr)) 16058feae131SDavid Howells return -EINVAL; 16068feae131SDavid Howells 16071da177e4SLinus Torvalds if (flags & MREMAP_FIXED && new_addr != addr) 16081da177e4SLinus Torvalds return (unsigned long) -EINVAL; 16091da177e4SLinus Torvalds 16108feae131SDavid Howells vma = find_vma_exact(current->mm, addr, old_len); 16116fa5f80bSDavid Howells if (!vma) 16121da177e4SLinus Torvalds return (unsigned long) -EINVAL; 16131da177e4SLinus Torvalds 16146fa5f80bSDavid Howells if (vma->vm_end != vma->vm_start + old_len) 16151da177e4SLinus Torvalds return (unsigned long) -EFAULT; 16161da177e4SLinus Torvalds 16176fa5f80bSDavid Howells if (vma->vm_flags & VM_MAYSHARE) 16181da177e4SLinus Torvalds return (unsigned long) -EPERM; 16191da177e4SLinus Torvalds 16208feae131SDavid Howells if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) 16211da177e4SLinus Torvalds return (unsigned long) -ENOMEM; 16221da177e4SLinus Torvalds 16231da177e4SLinus Torvalds /* all checks complete - do it */ 16246fa5f80bSDavid Howells vma->vm_end = vma->vm_start + new_len; 16256fa5f80bSDavid Howells return vma->vm_start; 16266fa5f80bSDavid Howells } 16276fa5f80bSDavid Howells 16286a6160a7SHeiko Carstens SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, 16296a6160a7SHeiko Carstens unsigned long, new_len, unsigned long, flags, 16306a6160a7SHeiko Carstens unsigned long, new_addr) 16316fa5f80bSDavid Howells { 16326fa5f80bSDavid Howells unsigned long ret; 16336fa5f80bSDavid Howells 1634*d8ed45c5SMichel Lespinasse mmap_write_lock(current->mm); 16356fa5f80bSDavid Howells ret = do_mremap(addr, old_len, new_len, flags, new_addr); 1636*d8ed45c5SMichel Lespinasse mmap_write_unlock(current->mm); 16376fa5f80bSDavid Howells return ret; 16381da177e4SLinus Torvalds } 16391da177e4SLinus Torvalds 1640df06b37fSKeith Busch struct page *follow_page(struct vm_area_struct *vma, unsigned long address, 1641df06b37fSKeith Busch unsigned int foll_flags) 16421da177e4SLinus Torvalds { 16431da177e4SLinus Torvalds return NULL; 16441da177e4SLinus Torvalds } 16451da177e4SLinus Torvalds 16468f3b1327SBob Liu int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, 16478f3b1327SBob Liu unsigned long pfn, unsigned long size, pgprot_t prot) 16481da177e4SLinus Torvalds { 16498f3b1327SBob Liu if (addr != (pfn << PAGE_SHIFT)) 16508f3b1327SBob Liu return -EINVAL; 16518f3b1327SBob Liu 1652314e51b9SKonstantin Khlebnikov vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; 165366aa2b4bSGreg Ungerer return 0; 16541da177e4SLinus Torvalds } 165522c4af40SLuke Yang EXPORT_SYMBOL(remap_pfn_range); 16561da177e4SLinus Torvalds 16573c0b9de6SLinus Torvalds int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len) 16583c0b9de6SLinus Torvalds { 16593c0b9de6SLinus Torvalds unsigned long pfn = start >> PAGE_SHIFT; 16603c0b9de6SLinus Torvalds unsigned long vm_len = vma->vm_end - vma->vm_start; 16613c0b9de6SLinus Torvalds 16623c0b9de6SLinus Torvalds pfn += vma->vm_pgoff; 16633c0b9de6SLinus Torvalds return io_remap_pfn_range(vma, vma->vm_start, pfn, vm_len, vma->vm_page_prot); 16643c0b9de6SLinus Torvalds } 16653c0b9de6SLinus Torvalds EXPORT_SYMBOL(vm_iomap_memory); 16663c0b9de6SLinus Torvalds 1667f905bc44SPaul Mundt int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 1668f905bc44SPaul Mundt unsigned long pgoff) 1669f905bc44SPaul Mundt { 1670f905bc44SPaul Mundt unsigned int size = vma->vm_end - vma->vm_start; 1671f905bc44SPaul Mundt 1672f905bc44SPaul Mundt if (!(vma->vm_flags & VM_USERMAP)) 1673f905bc44SPaul Mundt return -EINVAL; 1674f905bc44SPaul Mundt 1675f905bc44SPaul Mundt vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); 1676f905bc44SPaul Mundt vma->vm_end = vma->vm_start + size; 1677f905bc44SPaul Mundt 1678f905bc44SPaul Mundt return 0; 1679f905bc44SPaul Mundt } 1680f905bc44SPaul Mundt EXPORT_SYMBOL(remap_vmalloc_range); 1681f905bc44SPaul Mundt 16821da177e4SLinus Torvalds unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, 16831da177e4SLinus Torvalds unsigned long len, unsigned long pgoff, unsigned long flags) 16841da177e4SLinus Torvalds { 16851da177e4SLinus Torvalds return -ENOMEM; 16861da177e4SLinus Torvalds } 16871da177e4SLinus Torvalds 16882bcd6454SSouptick Joarder vm_fault_t filemap_fault(struct vm_fault *vmf) 1689b0e15190SDavid Howells { 1690b0e15190SDavid Howells BUG(); 1691d0217ac0SNick Piggin return 0; 1692b0e15190SDavid Howells } 1693b5073173SPaul Mundt EXPORT_SYMBOL(filemap_fault); 16940ec76a11SDavid Howells 169582b0f8c3SJan Kara void filemap_map_pages(struct vm_fault *vmf, 1696bae473a4SKirill A. Shutemov pgoff_t start_pgoff, pgoff_t end_pgoff) 1697f1820361SKirill A. Shutemov { 1698f1820361SKirill A. Shutemov BUG(); 1699f1820361SKirill A. Shutemov } 1700f1820361SKirill A. Shutemov EXPORT_SYMBOL(filemap_map_pages); 1701f1820361SKirill A. Shutemov 170284d77d3fSEric W. Biederman int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, 1703442486ecSLorenzo Stoakes unsigned long addr, void *buf, int len, unsigned int gup_flags) 17040ec76a11SDavid Howells { 17050ec76a11SDavid Howells struct vm_area_struct *vma; 1706442486ecSLorenzo Stoakes int write = gup_flags & FOLL_WRITE; 17070ec76a11SDavid Howells 1708*d8ed45c5SMichel Lespinasse if (mmap_read_lock_killable(mm)) 17091e426fe2SKonstantin Khlebnikov return 0; 17100ec76a11SDavid Howells 17110ec76a11SDavid Howells /* the access must start within one of the target process's mappings */ 17120159b141SDavid Howells vma = find_vma(mm, addr); 17130159b141SDavid Howells if (vma) { 17140ec76a11SDavid Howells /* don't overrun this mapping */ 17150ec76a11SDavid Howells if (addr + len >= vma->vm_end) 17160ec76a11SDavid Howells len = vma->vm_end - addr; 17170ec76a11SDavid Howells 17180ec76a11SDavid Howells /* only read or write mappings where it is permitted */ 1719d00c7b99SDavid Howells if (write && vma->vm_flags & VM_MAYWRITE) 17207959722bSJie Zhang copy_to_user_page(vma, NULL, addr, 17217959722bSJie Zhang (void *) addr, buf, len); 1722d00c7b99SDavid Howells else if (!write && vma->vm_flags & VM_MAYREAD) 17237959722bSJie Zhang copy_from_user_page(vma, NULL, addr, 17247959722bSJie Zhang buf, (void *) addr, len); 17250ec76a11SDavid Howells else 17260ec76a11SDavid Howells len = 0; 17270ec76a11SDavid Howells } else { 17280ec76a11SDavid Howells len = 0; 17290ec76a11SDavid Howells } 17300ec76a11SDavid Howells 1731*d8ed45c5SMichel Lespinasse mmap_read_unlock(mm); 1732f55f199bSMike Frysinger 1733f55f199bSMike Frysinger return len; 1734f55f199bSMike Frysinger } 1735f55f199bSMike Frysinger 1736f55f199bSMike Frysinger /** 1737b7701a5fSMike Rapoport * access_remote_vm - access another process' address space 1738f55f199bSMike Frysinger * @mm: the mm_struct of the target address space 1739f55f199bSMike Frysinger * @addr: start address to access 1740f55f199bSMike Frysinger * @buf: source or destination buffer 1741f55f199bSMike Frysinger * @len: number of bytes to transfer 17426347e8d5SLorenzo Stoakes * @gup_flags: flags modifying lookup behaviour 1743f55f199bSMike Frysinger * 1744f55f199bSMike Frysinger * The caller must hold a reference on @mm. 1745f55f199bSMike Frysinger */ 1746f55f199bSMike Frysinger int access_remote_vm(struct mm_struct *mm, unsigned long addr, 17476347e8d5SLorenzo Stoakes void *buf, int len, unsigned int gup_flags) 1748f55f199bSMike Frysinger { 17496347e8d5SLorenzo Stoakes return __access_remote_vm(NULL, mm, addr, buf, len, gup_flags); 1750f55f199bSMike Frysinger } 1751f55f199bSMike Frysinger 1752f55f199bSMike Frysinger /* 1753f55f199bSMike Frysinger * Access another process' address space. 1754f55f199bSMike Frysinger * - source/target buffer must be kernel space 1755f55f199bSMike Frysinger */ 1756f307ab6dSLorenzo Stoakes int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, 1757f307ab6dSLorenzo Stoakes unsigned int gup_flags) 1758f55f199bSMike Frysinger { 1759f55f199bSMike Frysinger struct mm_struct *mm; 1760f55f199bSMike Frysinger 1761f55f199bSMike Frysinger if (addr + len < addr) 1762f55f199bSMike Frysinger return 0; 1763f55f199bSMike Frysinger 1764f55f199bSMike Frysinger mm = get_task_mm(tsk); 1765f55f199bSMike Frysinger if (!mm) 1766f55f199bSMike Frysinger return 0; 1767f55f199bSMike Frysinger 1768f307ab6dSLorenzo Stoakes len = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags); 1769f55f199bSMike Frysinger 17700ec76a11SDavid Howells mmput(mm); 17710ec76a11SDavid Howells return len; 17720ec76a11SDavid Howells } 1773fcd35857SCatalin Marinas EXPORT_SYMBOL_GPL(access_process_vm); 17747e660872SDavid Howells 17757e660872SDavid Howells /** 17767e660872SDavid Howells * nommu_shrink_inode_mappings - Shrink the shared mappings on an inode 17777e660872SDavid Howells * @inode: The inode to check 17787e660872SDavid Howells * @size: The current filesize of the inode 17797e660872SDavid Howells * @newsize: The proposed filesize of the inode 17807e660872SDavid Howells * 17817e660872SDavid Howells * Check the shared mappings on an inode on behalf of a shrinking truncate to 17827e660872SDavid Howells * make sure that that any outstanding VMAs aren't broken and then shrink the 17837e660872SDavid Howells * vm_regions that extend that beyond so that do_mmap_pgoff() doesn't 17847e660872SDavid Howells * automatically grant mappings that are too large. 17857e660872SDavid Howells */ 17867e660872SDavid Howells int nommu_shrink_inode_mappings(struct inode *inode, size_t size, 17877e660872SDavid Howells size_t newsize) 17887e660872SDavid Howells { 17897e660872SDavid Howells struct vm_area_struct *vma; 17907e660872SDavid Howells struct vm_region *region; 17917e660872SDavid Howells pgoff_t low, high; 17927e660872SDavid Howells size_t r_size, r_top; 17937e660872SDavid Howells 17947e660872SDavid Howells low = newsize >> PAGE_SHIFT; 17957e660872SDavid Howells high = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 17967e660872SDavid Howells 17977e660872SDavid Howells down_write(&nommu_region_sem); 17981acf2e04SDavidlohr Bueso i_mmap_lock_read(inode->i_mapping); 17997e660872SDavid Howells 18007e660872SDavid Howells /* search for VMAs that fall within the dead zone */ 18016b2dbba8SMichel Lespinasse vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, low, high) { 18027e660872SDavid Howells /* found one - only interested if it's shared out of the page 18037e660872SDavid Howells * cache */ 18047e660872SDavid Howells if (vma->vm_flags & VM_SHARED) { 18051acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 18067e660872SDavid Howells up_write(&nommu_region_sem); 18077e660872SDavid Howells return -ETXTBSY; /* not quite true, but near enough */ 18087e660872SDavid Howells } 18097e660872SDavid Howells } 18107e660872SDavid Howells 18117e660872SDavid Howells /* reduce any regions that overlap the dead zone - if in existence, 18127e660872SDavid Howells * these will be pointed to by VMAs that don't overlap the dead zone 18137e660872SDavid Howells * 18147e660872SDavid Howells * we don't check for any regions that start beyond the EOF as there 18157e660872SDavid Howells * shouldn't be any 18167e660872SDavid Howells */ 18171acf2e04SDavidlohr Bueso vma_interval_tree_foreach(vma, &inode->i_mapping->i_mmap, 0, ULONG_MAX) { 18187e660872SDavid Howells if (!(vma->vm_flags & VM_SHARED)) 18197e660872SDavid Howells continue; 18207e660872SDavid Howells 18217e660872SDavid Howells region = vma->vm_region; 18227e660872SDavid Howells r_size = region->vm_top - region->vm_start; 18237e660872SDavid Howells r_top = (region->vm_pgoff << PAGE_SHIFT) + r_size; 18247e660872SDavid Howells 18257e660872SDavid Howells if (r_top > newsize) { 18267e660872SDavid Howells region->vm_top -= r_top - newsize; 18277e660872SDavid Howells if (region->vm_end > region->vm_top) 18287e660872SDavid Howells region->vm_end = region->vm_top; 18297e660872SDavid Howells } 18307e660872SDavid Howells } 18317e660872SDavid Howells 18321acf2e04SDavidlohr Bueso i_mmap_unlock_read(inode->i_mapping); 18337e660872SDavid Howells up_write(&nommu_region_sem); 18347e660872SDavid Howells return 0; 18357e660872SDavid Howells } 1836c9b1d098SAndrew Shewmaker 1837c9b1d098SAndrew Shewmaker /* 1838c9b1d098SAndrew Shewmaker * Initialise sysctl_user_reserve_kbytes. 1839c9b1d098SAndrew Shewmaker * 1840c9b1d098SAndrew Shewmaker * This is intended to prevent a user from starting a single memory hogging 1841c9b1d098SAndrew Shewmaker * process, such that they cannot recover (kill the hog) in OVERCOMMIT_NEVER 1842c9b1d098SAndrew Shewmaker * mode. 1843c9b1d098SAndrew Shewmaker * 1844c9b1d098SAndrew Shewmaker * The default value is min(3% of free memory, 128MB) 1845c9b1d098SAndrew Shewmaker * 128MB is enough to recover with sshd/login, bash, and top/kill. 1846c9b1d098SAndrew Shewmaker */ 1847c9b1d098SAndrew Shewmaker static int __meminit init_user_reserve(void) 1848c9b1d098SAndrew Shewmaker { 1849c9b1d098SAndrew Shewmaker unsigned long free_kbytes; 1850c9b1d098SAndrew Shewmaker 1851c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 1852c9b1d098SAndrew Shewmaker 1853c9b1d098SAndrew Shewmaker sysctl_user_reserve_kbytes = min(free_kbytes / 32, 1UL << 17); 1854c9b1d098SAndrew Shewmaker return 0; 1855c9b1d098SAndrew Shewmaker } 1856a4bc6fc7SPaul Gortmaker subsys_initcall(init_user_reserve); 18574eeab4f5SAndrew Shewmaker 18584eeab4f5SAndrew Shewmaker /* 18594eeab4f5SAndrew Shewmaker * Initialise sysctl_admin_reserve_kbytes. 18604eeab4f5SAndrew Shewmaker * 18614eeab4f5SAndrew Shewmaker * The purpose of sysctl_admin_reserve_kbytes is to allow the sys admin 18624eeab4f5SAndrew Shewmaker * to log in and kill a memory hogging process. 18634eeab4f5SAndrew Shewmaker * 18644eeab4f5SAndrew Shewmaker * Systems with more than 256MB will reserve 8MB, enough to recover 18654eeab4f5SAndrew Shewmaker * with sshd, bash, and top in OVERCOMMIT_GUESS. Smaller systems will 18664eeab4f5SAndrew Shewmaker * only reserve 3% of free pages by default. 18674eeab4f5SAndrew Shewmaker */ 18684eeab4f5SAndrew Shewmaker static int __meminit init_admin_reserve(void) 18694eeab4f5SAndrew Shewmaker { 18704eeab4f5SAndrew Shewmaker unsigned long free_kbytes; 18714eeab4f5SAndrew Shewmaker 1872c41f012aSMichal Hocko free_kbytes = global_zone_page_state(NR_FREE_PAGES) << (PAGE_SHIFT - 10); 18734eeab4f5SAndrew Shewmaker 18744eeab4f5SAndrew Shewmaker sysctl_admin_reserve_kbytes = min(free_kbytes / 32, 1UL << 13); 18754eeab4f5SAndrew Shewmaker return 0; 18764eeab4f5SAndrew Shewmaker } 1877a4bc6fc7SPaul Gortmaker subsys_initcall(init_admin_reserve); 1878