Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/mm/nommu.c |
| 3 | * |
| 4 | * Replacement code for mm functions to support CPU's that don't |
| 5 | * have any form of memory management unit (thus no virtual memory). |
| 6 | * |
| 7 | * See Documentation/nommu-mmap.txt |
| 8 | * |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 9 | * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | * Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com> |
| 11 | * Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org> |
| 12 | * Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com> |
Paul Mundt | eb6434d | 2009-01-21 17:45:47 +0900 | [diff] [blame] | 13 | * Copyright (c) 2007-2009 Paul Mundt <lethal@linux-sh.org> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | */ |
| 15 | |
David Howells | f2b8544 | 2007-10-29 13:15:39 +0000 | [diff] [blame] | 16 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/mm.h> |
| 18 | #include <linux/mman.h> |
| 19 | #include <linux/swap.h> |
| 20 | #include <linux/file.h> |
| 21 | #include <linux/highmem.h> |
| 22 | #include <linux/pagemap.h> |
| 23 | #include <linux/slab.h> |
| 24 | #include <linux/vmalloc.h> |
Roland McGrath | fa8e26c | 2008-07-25 19:45:50 -0700 | [diff] [blame] | 25 | #include <linux/tracehook.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <linux/blkdev.h> |
| 27 | #include <linux/backing-dev.h> |
| 28 | #include <linux/mount.h> |
| 29 | #include <linux/personality.h> |
| 30 | #include <linux/security.h> |
| 31 | #include <linux/syscalls.h> |
| 32 | |
| 33 | #include <asm/uaccess.h> |
| 34 | #include <asm/tlb.h> |
| 35 | #include <asm/tlbflush.h> |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 36 | #include "internal.h" |
| 37 | |
| 38 | static inline __attribute__((format(printf, 1, 2))) |
| 39 | void no_printk(const char *fmt, ...) |
| 40 | { |
| 41 | } |
| 42 | |
| 43 | #if 0 |
| 44 | #define kenter(FMT, ...) \ |
| 45 | printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) |
| 46 | #define kleave(FMT, ...) \ |
| 47 | printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) |
| 48 | #define kdebug(FMT, ...) \ |
| 49 | printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__) |
| 50 | #else |
| 51 | #define kenter(FMT, ...) \ |
| 52 | no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__) |
| 53 | #define kleave(FMT, ...) \ |
| 54 | no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__) |
| 55 | #define kdebug(FMT, ...) \ |
| 56 | no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__) |
| 57 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 59 | #include "internal.h" |
| 60 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | void *high_memory; |
| 62 | struct page *mem_map; |
| 63 | unsigned long max_mapnr; |
| 64 | unsigned long num_physpages; |
KOSAKI Motohiro | 00a62ce | 2009-04-30 15:08:51 -0700 | [diff] [blame] | 65 | struct percpu_counter vm_committed_as; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ |
| 67 | int sysctl_overcommit_ratio = 50; /* default is 50% */ |
| 68 | int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 69 | int sysctl_nr_trim_pages = 1; /* page trimming behaviour */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | int heap_stack_gap = 0; |
| 71 | |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 72 | atomic_long_t mmap_pages_allocated; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 73 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | EXPORT_SYMBOL(mem_map); |
Wu, Bryan | 6a04de6 | 2007-04-11 23:28:47 -0700 | [diff] [blame] | 75 | EXPORT_SYMBOL(num_physpages); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 77 | /* list of mapped, potentially shareable regions */ |
| 78 | static struct kmem_cache *vm_region_jar; |
| 79 | struct rb_root nommu_region_tree = RB_ROOT; |
| 80 | DECLARE_RWSEM(nommu_region_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | |
| 82 | struct vm_operations_struct generic_file_vm_ops = { |
| 83 | }; |
| 84 | |
| 85 | /* |
| 86 | * Handle all mappings that got truncated by a "truncate()" |
| 87 | * system call. |
| 88 | * |
| 89 | * NOTE! We have to be ready to update the memory sharing |
| 90 | * between the file and the memory map for a potential last |
| 91 | * incomplete page. Ugly, but necessary. |
| 92 | */ |
| 93 | int vmtruncate(struct inode *inode, loff_t offset) |
| 94 | { |
| 95 | struct address_space *mapping = inode->i_mapping; |
| 96 | unsigned long limit; |
| 97 | |
| 98 | if (inode->i_size < offset) |
| 99 | goto do_expand; |
| 100 | i_size_write(inode, offset); |
| 101 | |
| 102 | truncate_inode_pages(mapping, offset); |
| 103 | goto out_truncate; |
| 104 | |
| 105 | do_expand: |
| 106 | limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; |
| 107 | if (limit != RLIM_INFINITY && offset > limit) |
| 108 | goto out_sig; |
| 109 | if (offset > inode->i_sb->s_maxbytes) |
| 110 | goto out; |
| 111 | i_size_write(inode, offset); |
| 112 | |
| 113 | out_truncate: |
Al Viro | acfa438 | 2008-12-04 10:06:33 -0500 | [diff] [blame] | 114 | if (inode->i_op->truncate) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | inode->i_op->truncate(inode); |
| 116 | return 0; |
| 117 | out_sig: |
| 118 | send_sig(SIGXFSZ, current, 0); |
| 119 | out: |
| 120 | return -EFBIG; |
| 121 | } |
| 122 | |
| 123 | EXPORT_SYMBOL(vmtruncate); |
| 124 | |
| 125 | /* |
| 126 | * Return the total memory allocated for this pointer, not |
| 127 | * just what the caller asked for. |
| 128 | * |
| 129 | * Doesn't have to be accurate, i.e. may have races. |
| 130 | */ |
| 131 | unsigned int kobjsize(const void *objp) |
| 132 | { |
| 133 | struct page *page; |
| 134 | |
Michael Hennerich | 4016a13 | 2008-04-28 02:13:38 -0700 | [diff] [blame] | 135 | /* |
| 136 | * If the object we have should not have ksize performed on it, |
| 137 | * return size of 0 |
| 138 | */ |
Paul Mundt | 5a1603b | 2008-06-12 16:29:55 +0900 | [diff] [blame] | 139 | if (!objp || !virt_addr_valid(objp)) |
Paul Mundt | 6cfd53fc | 2008-06-05 22:46:08 -0700 | [diff] [blame] | 140 | return 0; |
| 141 | |
| 142 | page = virt_to_head_page(objp); |
Paul Mundt | 6cfd53fc | 2008-06-05 22:46:08 -0700 | [diff] [blame] | 143 | |
| 144 | /* |
| 145 | * If the allocator sets PageSlab, we know the pointer came from |
| 146 | * kmalloc(). |
| 147 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | if (PageSlab(page)) |
| 149 | return ksize(objp); |
| 150 | |
Paul Mundt | 6cfd53fc | 2008-06-05 22:46:08 -0700 | [diff] [blame] | 151 | /* |
Paul Mundt | ab2e83e | 2009-01-08 12:04:48 +0000 | [diff] [blame] | 152 | * If it's not a compound page, see if we have a matching VMA |
| 153 | * region. This test is intentionally done in reverse order, |
| 154 | * so if there's no VMA, we still fall through and hand back |
| 155 | * PAGE_SIZE for 0-order pages. |
| 156 | */ |
| 157 | if (!PageCompound(page)) { |
| 158 | struct vm_area_struct *vma; |
| 159 | |
| 160 | vma = find_vma(current->mm, (unsigned long)objp); |
| 161 | if (vma) |
| 162 | return vma->vm_end - vma->vm_start; |
| 163 | } |
| 164 | |
| 165 | /* |
Paul Mundt | 6cfd53fc | 2008-06-05 22:46:08 -0700 | [diff] [blame] | 166 | * The ksize() function is only guaranteed to work for pointers |
Paul Mundt | 5a1603b | 2008-06-12 16:29:55 +0900 | [diff] [blame] | 167 | * returned by kmalloc(). So handle arbitrary pointers here. |
Paul Mundt | 6cfd53fc | 2008-06-05 22:46:08 -0700 | [diff] [blame] | 168 | */ |
Paul Mundt | 5a1603b | 2008-06-12 16:29:55 +0900 | [diff] [blame] | 169 | return PAGE_SIZE << compound_order(page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | } |
| 171 | |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 172 | int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
| 173 | unsigned long start, int len, int flags, |
| 174 | struct page **pages, struct vm_area_struct **vmas) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | { |
Sonic Zhang | 910e46d | 2006-09-27 01:50:17 -0700 | [diff] [blame] | 176 | struct vm_area_struct *vma; |
David Howells | 7b4d5b8 | 2006-09-27 01:50:18 -0700 | [diff] [blame] | 177 | unsigned long vm_flags; |
| 178 | int i; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 179 | int write = !!(flags & GUP_FLAGS_WRITE); |
| 180 | int force = !!(flags & GUP_FLAGS_FORCE); |
| 181 | int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS); |
David Howells | 7b4d5b8 | 2006-09-27 01:50:18 -0700 | [diff] [blame] | 182 | |
| 183 | /* calculate required read or write permissions. |
| 184 | * - if 'force' is set, we only require the "MAY" flags. |
| 185 | */ |
| 186 | vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); |
| 187 | vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
| 189 | for (i = 0; i < len; i++) { |
Sonic Zhang | 910e46d | 2006-09-27 01:50:17 -0700 | [diff] [blame] | 190 | vma = find_vma(mm, start); |
David Howells | 7b4d5b8 | 2006-09-27 01:50:18 -0700 | [diff] [blame] | 191 | if (!vma) |
| 192 | goto finish_or_fault; |
| 193 | |
| 194 | /* protect what we can, including chardevs */ |
| 195 | if (vma->vm_flags & (VM_IO | VM_PFNMAP) || |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 196 | (!ignore && !(vm_flags & vma->vm_flags))) |
David Howells | 7b4d5b8 | 2006-09-27 01:50:18 -0700 | [diff] [blame] | 197 | goto finish_or_fault; |
Sonic Zhang | 910e46d | 2006-09-27 01:50:17 -0700 | [diff] [blame] | 198 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | if (pages) { |
| 200 | pages[i] = virt_to_page(start); |
| 201 | if (pages[i]) |
| 202 | page_cache_get(pages[i]); |
| 203 | } |
| 204 | if (vmas) |
Sonic Zhang | 910e46d | 2006-09-27 01:50:17 -0700 | [diff] [blame] | 205 | vmas[i] = vma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | start += PAGE_SIZE; |
| 207 | } |
David Howells | 7b4d5b8 | 2006-09-27 01:50:18 -0700 | [diff] [blame] | 208 | |
| 209 | return i; |
| 210 | |
| 211 | finish_or_fault: |
| 212 | return i ? : -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | } |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 214 | |
| 215 | |
| 216 | /* |
| 217 | * get a list of pages in an address range belonging to the specified process |
| 218 | * and indicate the VMA that covers each page |
| 219 | * - this is potentially dodgy as we may end incrementing the page count of a |
| 220 | * slab page or a secondary page from a compound page |
| 221 | * - don't permit access to VMAs that don't support it, such as I/O mappings |
| 222 | */ |
| 223 | int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, |
| 224 | unsigned long start, int len, int write, int force, |
| 225 | struct page **pages, struct vm_area_struct **vmas) |
| 226 | { |
| 227 | int flags = 0; |
| 228 | |
| 229 | if (write) |
| 230 | flags |= GUP_FLAGS_WRITE; |
| 231 | if (force) |
| 232 | flags |= GUP_FLAGS_FORCE; |
| 233 | |
| 234 | return __get_user_pages(tsk, mm, |
| 235 | start, len, flags, |
| 236 | pages, vmas); |
| 237 | } |
Greg Ungerer | 66aa2b4 | 2005-09-12 11:18:10 +1000 | [diff] [blame] | 238 | EXPORT_SYMBOL(get_user_pages); |
| 239 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | DEFINE_RWLOCK(vmlist_lock); |
| 241 | struct vm_struct *vmlist; |
| 242 | |
Christoph Lameter | b3bdda0 | 2008-02-04 22:28:32 -0800 | [diff] [blame] | 243 | void vfree(const void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 244 | { |
| 245 | kfree(addr); |
| 246 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 247 | EXPORT_SYMBOL(vfree); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 249 | void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | { |
| 251 | /* |
Robert P. J. Day | 8518609 | 2007-10-19 23:11:38 +0200 | [diff] [blame] | 252 | * You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc() |
| 253 | * returns only a logical address. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | */ |
Nick Piggin | 8409751 | 2006-03-22 00:08:34 -0800 | [diff] [blame] | 255 | return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 257 | EXPORT_SYMBOL(__vmalloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | |
Paul Mundt | f905bc4 | 2008-02-04 22:29:59 -0800 | [diff] [blame] | 259 | void *vmalloc_user(unsigned long size) |
| 260 | { |
| 261 | void *ret; |
| 262 | |
| 263 | ret = __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, |
| 264 | PAGE_KERNEL); |
| 265 | if (ret) { |
| 266 | struct vm_area_struct *vma; |
| 267 | |
| 268 | down_write(¤t->mm->mmap_sem); |
| 269 | vma = find_vma(current->mm, (unsigned long)ret); |
| 270 | if (vma) |
| 271 | vma->vm_flags |= VM_USERMAP; |
| 272 | up_write(¤t->mm->mmap_sem); |
| 273 | } |
| 274 | |
| 275 | return ret; |
| 276 | } |
| 277 | EXPORT_SYMBOL(vmalloc_user); |
| 278 | |
Christoph Lameter | b3bdda0 | 2008-02-04 22:28:32 -0800 | [diff] [blame] | 279 | struct page *vmalloc_to_page(const void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | { |
| 281 | return virt_to_page(addr); |
| 282 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 283 | EXPORT_SYMBOL(vmalloc_to_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | |
Christoph Lameter | b3bdda0 | 2008-02-04 22:28:32 -0800 | [diff] [blame] | 285 | unsigned long vmalloc_to_pfn(const void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | { |
| 287 | return page_to_pfn(virt_to_page(addr)); |
| 288 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 289 | EXPORT_SYMBOL(vmalloc_to_pfn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | |
| 291 | long vread(char *buf, char *addr, unsigned long count) |
| 292 | { |
| 293 | memcpy(buf, addr, count); |
| 294 | return count; |
| 295 | } |
| 296 | |
| 297 | long vwrite(char *buf, char *addr, unsigned long count) |
| 298 | { |
| 299 | /* Don't allow overflow */ |
| 300 | if ((unsigned long) addr + count < count) |
| 301 | count = -(unsigned long) addr; |
| 302 | |
| 303 | memcpy(addr, buf, count); |
| 304 | return(count); |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * vmalloc - allocate virtually continguos memory |
| 309 | * |
| 310 | * @size: allocation size |
| 311 | * |
| 312 | * Allocate enough pages to cover @size from the page level |
| 313 | * allocator and map them into continguos kernel virtual space. |
| 314 | * |
Michael Opdenacker | c1c8897 | 2006-10-03 23:21:02 +0200 | [diff] [blame] | 315 | * For tight control over page level allocator and protection flags |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | * use __vmalloc() instead. |
| 317 | */ |
| 318 | void *vmalloc(unsigned long size) |
| 319 | { |
| 320 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL); |
| 321 | } |
Andrew Morton | f613888 | 2006-02-28 16:59:18 -0800 | [diff] [blame] | 322 | EXPORT_SYMBOL(vmalloc); |
| 323 | |
| 324 | void *vmalloc_node(unsigned long size, int node) |
| 325 | { |
| 326 | return vmalloc(size); |
| 327 | } |
| 328 | EXPORT_SYMBOL(vmalloc_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | |
Paul Mundt | 1af446e | 2008-08-04 16:01:47 +0900 | [diff] [blame] | 330 | #ifndef PAGE_KERNEL_EXEC |
| 331 | # define PAGE_KERNEL_EXEC PAGE_KERNEL |
| 332 | #endif |
| 333 | |
| 334 | /** |
| 335 | * vmalloc_exec - allocate virtually contiguous, executable memory |
| 336 | * @size: allocation size |
| 337 | * |
| 338 | * Kernel-internal function to allocate enough pages to cover @size |
| 339 | * the page level allocator and map them into contiguous and |
| 340 | * executable kernel virtual space. |
| 341 | * |
| 342 | * For tight control over page level allocator and protection flags |
| 343 | * use __vmalloc() instead. |
| 344 | */ |
| 345 | |
| 346 | void *vmalloc_exec(unsigned long size) |
| 347 | { |
| 348 | return __vmalloc(size, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC); |
| 349 | } |
| 350 | |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 351 | /** |
| 352 | * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | * @size: allocation size |
| 354 | * |
| 355 | * Allocate enough 32bit PA addressable pages to cover @size from the |
| 356 | * page level allocator and map them into continguos kernel virtual space. |
| 357 | */ |
| 358 | void *vmalloc_32(unsigned long size) |
| 359 | { |
| 360 | return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL); |
| 361 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 362 | EXPORT_SYMBOL(vmalloc_32); |
| 363 | |
| 364 | /** |
| 365 | * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory |
| 366 | * @size: allocation size |
| 367 | * |
| 368 | * The resulting memory area is 32bit addressable and zeroed so it can be |
| 369 | * mapped to userspace without leaking data. |
Paul Mundt | f905bc4 | 2008-02-04 22:29:59 -0800 | [diff] [blame] | 370 | * |
| 371 | * VM_USERMAP is set on the corresponding VMA so that subsequent calls to |
| 372 | * remap_vmalloc_range() are permissible. |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 373 | */ |
| 374 | void *vmalloc_32_user(unsigned long size) |
| 375 | { |
Paul Mundt | f905bc4 | 2008-02-04 22:29:59 -0800 | [diff] [blame] | 376 | /* |
| 377 | * We'll have to sort out the ZONE_DMA bits for 64-bit, |
| 378 | * but for now this can simply use vmalloc_user() directly. |
| 379 | */ |
| 380 | return vmalloc_user(size); |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 381 | } |
| 382 | EXPORT_SYMBOL(vmalloc_32_user); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | |
| 384 | void *vmap(struct page **pages, unsigned int count, unsigned long flags, pgprot_t prot) |
| 385 | { |
| 386 | BUG(); |
| 387 | return NULL; |
| 388 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 389 | EXPORT_SYMBOL(vmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | |
Christoph Lameter | b3bdda0 | 2008-02-04 22:28:32 -0800 | [diff] [blame] | 391 | void vunmap(const void *addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | { |
| 393 | BUG(); |
| 394 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 395 | EXPORT_SYMBOL(vunmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | |
Paul Mundt | eb6434d | 2009-01-21 17:45:47 +0900 | [diff] [blame] | 397 | void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) |
| 398 | { |
| 399 | BUG(); |
| 400 | return NULL; |
| 401 | } |
| 402 | EXPORT_SYMBOL(vm_map_ram); |
| 403 | |
| 404 | void vm_unmap_ram(const void *mem, unsigned int count) |
| 405 | { |
| 406 | BUG(); |
| 407 | } |
| 408 | EXPORT_SYMBOL(vm_unmap_ram); |
| 409 | |
| 410 | void vm_unmap_aliases(void) |
| 411 | { |
| 412 | } |
| 413 | EXPORT_SYMBOL_GPL(vm_unmap_aliases); |
| 414 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | /* |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 416 | * Implement a stub for vmalloc_sync_all() if the architecture chose not to |
| 417 | * have one. |
| 418 | */ |
| 419 | void __attribute__((weak)) vmalloc_sync_all(void) |
| 420 | { |
| 421 | } |
| 422 | |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 423 | int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, |
| 424 | struct page *page) |
| 425 | { |
| 426 | return -EINVAL; |
| 427 | } |
| 428 | EXPORT_SYMBOL(vm_insert_page); |
| 429 | |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 430 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | * sys_brk() for the most part doesn't need the global kernel |
| 432 | * lock, except when an application is doing something nasty |
| 433 | * like trying to un-brk an area that has already been mapped |
| 434 | * to a regular file. in this case, the unmapping will need |
| 435 | * to invoke file system routines that need the global lock. |
| 436 | */ |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 437 | SYSCALL_DEFINE1(brk, unsigned long, brk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | { |
| 439 | struct mm_struct *mm = current->mm; |
| 440 | |
| 441 | if (brk < mm->start_brk || brk > mm->context.end_brk) |
| 442 | return mm->brk; |
| 443 | |
| 444 | if (mm->brk == brk) |
| 445 | return mm->brk; |
| 446 | |
| 447 | /* |
| 448 | * Always allow shrinking brk |
| 449 | */ |
| 450 | if (brk <= mm->brk) { |
| 451 | mm->brk = brk; |
| 452 | return brk; |
| 453 | } |
| 454 | |
| 455 | /* |
| 456 | * Ok, looks good - let it rip. |
| 457 | */ |
| 458 | return mm->brk = brk; |
| 459 | } |
| 460 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 461 | /* |
| 462 | * initialise the VMA and region record slabs |
| 463 | */ |
| 464 | void __init mmap_init(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | { |
KOSAKI Motohiro | 00a62ce | 2009-04-30 15:08:51 -0700 | [diff] [blame] | 466 | int ret; |
| 467 | |
| 468 | ret = percpu_counter_init(&vm_committed_as, 0); |
| 469 | VM_BUG_ON(ret); |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 470 | vm_region_jar = KMEM_CACHE(vm_region, SLAB_PANIC); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 471 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 473 | /* |
| 474 | * validate the region tree |
| 475 | * - the caller must hold the region lock |
| 476 | */ |
| 477 | #ifdef CONFIG_DEBUG_NOMMU_REGIONS |
| 478 | static noinline void validate_nommu_regions(void) |
| 479 | { |
| 480 | struct vm_region *region, *last; |
| 481 | struct rb_node *p, *lastp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 483 | lastp = rb_first(&nommu_region_tree); |
| 484 | if (!lastp) |
| 485 | return; |
| 486 | |
| 487 | last = rb_entry(lastp, struct vm_region, vm_rb); |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 488 | BUG_ON(unlikely(last->vm_end <= last->vm_start)); |
| 489 | BUG_ON(unlikely(last->vm_top < last->vm_end)); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 490 | |
| 491 | while ((p = rb_next(lastp))) { |
| 492 | region = rb_entry(p, struct vm_region, vm_rb); |
| 493 | last = rb_entry(lastp, struct vm_region, vm_rb); |
| 494 | |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 495 | BUG_ON(unlikely(region->vm_end <= region->vm_start)); |
| 496 | BUG_ON(unlikely(region->vm_top < region->vm_end)); |
| 497 | BUG_ON(unlikely(region->vm_start < last->vm_top)); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 498 | |
| 499 | lastp = p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | } |
| 501 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 502 | #else |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 503 | static void validate_nommu_regions(void) |
| 504 | { |
| 505 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 506 | #endif |
| 507 | |
| 508 | /* |
| 509 | * add a region into the global tree |
| 510 | */ |
| 511 | static void add_nommu_region(struct vm_region *region) |
| 512 | { |
| 513 | struct vm_region *pregion; |
| 514 | struct rb_node **p, *parent; |
| 515 | |
| 516 | validate_nommu_regions(); |
| 517 | |
| 518 | BUG_ON(region->vm_start & ~PAGE_MASK); |
| 519 | |
| 520 | parent = NULL; |
| 521 | p = &nommu_region_tree.rb_node; |
| 522 | while (*p) { |
| 523 | parent = *p; |
| 524 | pregion = rb_entry(parent, struct vm_region, vm_rb); |
| 525 | if (region->vm_start < pregion->vm_start) |
| 526 | p = &(*p)->rb_left; |
| 527 | else if (region->vm_start > pregion->vm_start) |
| 528 | p = &(*p)->rb_right; |
| 529 | else if (pregion == region) |
| 530 | return; |
| 531 | else |
| 532 | BUG(); |
| 533 | } |
| 534 | |
| 535 | rb_link_node(®ion->vm_rb, parent, p); |
| 536 | rb_insert_color(®ion->vm_rb, &nommu_region_tree); |
| 537 | |
| 538 | validate_nommu_regions(); |
| 539 | } |
| 540 | |
| 541 | /* |
| 542 | * delete a region from the global tree |
| 543 | */ |
| 544 | static void delete_nommu_region(struct vm_region *region) |
| 545 | { |
| 546 | BUG_ON(!nommu_region_tree.rb_node); |
| 547 | |
| 548 | validate_nommu_regions(); |
| 549 | rb_erase(®ion->vm_rb, &nommu_region_tree); |
| 550 | validate_nommu_regions(); |
| 551 | } |
| 552 | |
| 553 | /* |
| 554 | * free a contiguous series of pages |
| 555 | */ |
| 556 | static void free_page_series(unsigned long from, unsigned long to) |
| 557 | { |
| 558 | for (; from < to; from += PAGE_SIZE) { |
| 559 | struct page *page = virt_to_page(from); |
| 560 | |
| 561 | kdebug("- free %lx", from); |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 562 | atomic_long_dec(&mmap_pages_allocated); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 563 | if (page_count(page) != 1) |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 564 | kdebug("free page %p: refcount not one: %d", |
| 565 | page, page_count(page)); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 566 | put_page(page); |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | /* |
| 571 | * release a reference to a region |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 572 | * - the caller must hold the region semaphore for writing, which this releases |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 573 | * - the region may not have been added to the tree yet, in which case vm_top |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 574 | * will equal vm_start |
| 575 | */ |
| 576 | static void __put_nommu_region(struct vm_region *region) |
| 577 | __releases(nommu_region_sem) |
| 578 | { |
| 579 | kenter("%p{%d}", region, atomic_read(®ion->vm_usage)); |
| 580 | |
| 581 | BUG_ON(!nommu_region_tree.rb_node); |
| 582 | |
| 583 | if (atomic_dec_and_test(®ion->vm_usage)) { |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 584 | if (region->vm_top > region->vm_start) |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 585 | delete_nommu_region(region); |
| 586 | up_write(&nommu_region_sem); |
| 587 | |
| 588 | if (region->vm_file) |
| 589 | fput(region->vm_file); |
| 590 | |
| 591 | /* IO memory and memory shared directly out of the pagecache |
| 592 | * from ramfs/tmpfs mustn't be released here */ |
| 593 | if (region->vm_flags & VM_MAPPED_COPY) { |
| 594 | kdebug("free series"); |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 595 | free_page_series(region->vm_start, region->vm_top); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 596 | } |
| 597 | kmem_cache_free(vm_region_jar, region); |
| 598 | } else { |
| 599 | up_write(&nommu_region_sem); |
| 600 | } |
| 601 | } |
| 602 | |
| 603 | /* |
| 604 | * release a reference to a region |
| 605 | */ |
| 606 | static void put_nommu_region(struct vm_region *region) |
| 607 | { |
| 608 | down_write(&nommu_region_sem); |
| 609 | __put_nommu_region(region); |
| 610 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 611 | |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 612 | /* |
| 613 | * add a VMA into a process's mm_struct in the appropriate place in the list |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 614 | * and tree and add to the address space's page tree also if not an anonymous |
| 615 | * page |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 616 | * - should be called with mm->mmap_sem held writelocked |
| 617 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 618 | static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma) |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 619 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 620 | struct vm_area_struct *pvma, **pp; |
| 621 | struct address_space *mapping; |
| 622 | struct rb_node **p, *parent; |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 623 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 624 | kenter(",%p", vma); |
| 625 | |
| 626 | BUG_ON(!vma->vm_region); |
| 627 | |
| 628 | mm->map_count++; |
| 629 | vma->vm_mm = mm; |
| 630 | |
| 631 | /* add the VMA to the mapping */ |
| 632 | if (vma->vm_file) { |
| 633 | mapping = vma->vm_file->f_mapping; |
| 634 | |
| 635 | flush_dcache_mmap_lock(mapping); |
| 636 | vma_prio_tree_insert(vma, &mapping->i_mmap); |
| 637 | flush_dcache_mmap_unlock(mapping); |
| 638 | } |
| 639 | |
| 640 | /* add the VMA to the tree */ |
| 641 | parent = NULL; |
| 642 | p = &mm->mm_rb.rb_node; |
| 643 | while (*p) { |
| 644 | parent = *p; |
| 645 | pvma = rb_entry(parent, struct vm_area_struct, vm_rb); |
| 646 | |
| 647 | /* sort by: start addr, end addr, VMA struct addr in that order |
| 648 | * (the latter is necessary as we may get identical VMAs) */ |
| 649 | if (vma->vm_start < pvma->vm_start) |
| 650 | p = &(*p)->rb_left; |
| 651 | else if (vma->vm_start > pvma->vm_start) |
| 652 | p = &(*p)->rb_right; |
| 653 | else if (vma->vm_end < pvma->vm_end) |
| 654 | p = &(*p)->rb_left; |
| 655 | else if (vma->vm_end > pvma->vm_end) |
| 656 | p = &(*p)->rb_right; |
| 657 | else if (vma < pvma) |
| 658 | p = &(*p)->rb_left; |
| 659 | else if (vma > pvma) |
| 660 | p = &(*p)->rb_right; |
| 661 | else |
| 662 | BUG(); |
| 663 | } |
| 664 | |
| 665 | rb_link_node(&vma->vm_rb, parent, p); |
| 666 | rb_insert_color(&vma->vm_rb, &mm->mm_rb); |
| 667 | |
| 668 | /* add VMA to the VMA list also */ |
| 669 | for (pp = &mm->mmap; (pvma = *pp); pp = &(*pp)->vm_next) { |
| 670 | if (pvma->vm_start > vma->vm_start) |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 671 | break; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 672 | if (pvma->vm_start < vma->vm_start) |
| 673 | continue; |
| 674 | if (pvma->vm_end < vma->vm_end) |
| 675 | break; |
| 676 | } |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 677 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 678 | vma->vm_next = *pp; |
| 679 | *pp = vma; |
| 680 | } |
| 681 | |
| 682 | /* |
| 683 | * delete a VMA from its owning mm_struct and address space |
| 684 | */ |
| 685 | static void delete_vma_from_mm(struct vm_area_struct *vma) |
| 686 | { |
| 687 | struct vm_area_struct **pp; |
| 688 | struct address_space *mapping; |
| 689 | struct mm_struct *mm = vma->vm_mm; |
| 690 | |
| 691 | kenter("%p", vma); |
| 692 | |
| 693 | mm->map_count--; |
| 694 | if (mm->mmap_cache == vma) |
| 695 | mm->mmap_cache = NULL; |
| 696 | |
| 697 | /* remove the VMA from the mapping */ |
| 698 | if (vma->vm_file) { |
| 699 | mapping = vma->vm_file->f_mapping; |
| 700 | |
| 701 | flush_dcache_mmap_lock(mapping); |
| 702 | vma_prio_tree_remove(vma, &mapping->i_mmap); |
| 703 | flush_dcache_mmap_unlock(mapping); |
| 704 | } |
| 705 | |
| 706 | /* remove from the MM's tree and list */ |
| 707 | rb_erase(&vma->vm_rb, &mm->mm_rb); |
| 708 | for (pp = &mm->mmap; *pp; pp = &(*pp)->vm_next) { |
| 709 | if (*pp == vma) { |
| 710 | *pp = vma->vm_next; |
| 711 | break; |
| 712 | } |
| 713 | } |
| 714 | |
| 715 | vma->vm_mm = NULL; |
| 716 | } |
| 717 | |
| 718 | /* |
| 719 | * destroy a VMA record |
| 720 | */ |
| 721 | static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma) |
| 722 | { |
| 723 | kenter("%p", vma); |
| 724 | if (vma->vm_ops && vma->vm_ops->close) |
| 725 | vma->vm_ops->close(vma); |
| 726 | if (vma->vm_file) { |
| 727 | fput(vma->vm_file); |
| 728 | if (vma->vm_flags & VM_EXECUTABLE) |
| 729 | removed_exe_file_vma(mm); |
| 730 | } |
| 731 | put_nommu_region(vma->vm_region); |
| 732 | kmem_cache_free(vm_area_cachep, vma); |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 733 | } |
| 734 | |
| 735 | /* |
| 736 | * look up the first VMA in which addr resides, NULL if none |
| 737 | * - should be called with mm->mmap_sem at least held readlocked |
| 738 | */ |
| 739 | struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr) |
| 740 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 741 | struct vm_area_struct *vma; |
| 742 | struct rb_node *n = mm->mm_rb.rb_node; |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 743 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 744 | /* check the cache first */ |
| 745 | vma = mm->mmap_cache; |
| 746 | if (vma && vma->vm_start <= addr && vma->vm_end > addr) |
| 747 | return vma; |
| 748 | |
| 749 | /* trawl the tree (there may be multiple mappings in which addr |
| 750 | * resides) */ |
| 751 | for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) { |
| 752 | vma = rb_entry(n, struct vm_area_struct, vm_rb); |
| 753 | if (vma->vm_start > addr) |
| 754 | return NULL; |
| 755 | if (vma->vm_end > addr) { |
| 756 | mm->mmap_cache = vma; |
| 757 | return vma; |
| 758 | } |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 759 | } |
| 760 | |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 761 | return NULL; |
| 762 | } |
| 763 | EXPORT_SYMBOL(find_vma); |
| 764 | |
| 765 | /* |
David Howells | 930e652 | 2006-09-27 01:50:22 -0700 | [diff] [blame] | 766 | * find a VMA |
| 767 | * - we don't extend stack VMAs under NOMMU conditions |
| 768 | */ |
| 769 | struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr) |
| 770 | { |
| 771 | return find_vma(mm, addr); |
| 772 | } |
| 773 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 774 | /* |
| 775 | * expand a stack to a given address |
| 776 | * - not supported under NOMMU conditions |
| 777 | */ |
Greg Ungerer | 57c8f63 | 2007-07-15 23:38:28 -0700 | [diff] [blame] | 778 | int expand_stack(struct vm_area_struct *vma, unsigned long address) |
| 779 | { |
| 780 | return -ENOMEM; |
| 781 | } |
| 782 | |
David Howells | 930e652 | 2006-09-27 01:50:22 -0700 | [diff] [blame] | 783 | /* |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 784 | * look up the first VMA exactly that exactly matches addr |
| 785 | * - should be called with mm->mmap_sem at least held readlocked |
| 786 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 787 | static struct vm_area_struct *find_vma_exact(struct mm_struct *mm, |
| 788 | unsigned long addr, |
| 789 | unsigned long len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 790 | { |
| 791 | struct vm_area_struct *vma; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 792 | struct rb_node *n = mm->mm_rb.rb_node; |
| 793 | unsigned long end = addr + len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 795 | /* check the cache first */ |
| 796 | vma = mm->mmap_cache; |
| 797 | if (vma && vma->vm_start == addr && vma->vm_end == end) |
| 798 | return vma; |
| 799 | |
| 800 | /* trawl the tree (there may be multiple mappings in which addr |
| 801 | * resides) */ |
| 802 | for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | vma = rb_entry(n, struct vm_area_struct, vm_rb); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 804 | if (vma->vm_start < addr) |
| 805 | continue; |
| 806 | if (vma->vm_start > addr) |
| 807 | return NULL; |
| 808 | if (vma->vm_end == end) { |
| 809 | mm->mmap_cache = vma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | return vma; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 811 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | } |
| 813 | |
| 814 | return NULL; |
| 815 | } |
| 816 | |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 817 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | * determine whether a mapping should be permitted and, if so, what sort of |
| 819 | * mapping we're capable of supporting |
| 820 | */ |
| 821 | static int validate_mmap_request(struct file *file, |
| 822 | unsigned long addr, |
| 823 | unsigned long len, |
| 824 | unsigned long prot, |
| 825 | unsigned long flags, |
| 826 | unsigned long pgoff, |
| 827 | unsigned long *_capabilities) |
| 828 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 829 | unsigned long capabilities, rlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | unsigned long reqprot = prot; |
| 831 | int ret; |
| 832 | |
| 833 | /* do the simple checks first */ |
| 834 | if (flags & MAP_FIXED || addr) { |
| 835 | printk(KERN_DEBUG |
| 836 | "%d: Can't do fixed-address/overlay mmap of RAM\n", |
| 837 | current->pid); |
| 838 | return -EINVAL; |
| 839 | } |
| 840 | |
| 841 | if ((flags & MAP_TYPE) != MAP_PRIVATE && |
| 842 | (flags & MAP_TYPE) != MAP_SHARED) |
| 843 | return -EINVAL; |
| 844 | |
Mike Frysinger | f81cff0 | 2006-12-06 12:02:59 +1000 | [diff] [blame] | 845 | if (!len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | return -EINVAL; |
| 847 | |
Mike Frysinger | f81cff0 | 2006-12-06 12:02:59 +1000 | [diff] [blame] | 848 | /* Careful about overflows.. */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 849 | rlen = PAGE_ALIGN(len); |
| 850 | if (!rlen || rlen > TASK_SIZE) |
Mike Frysinger | f81cff0 | 2006-12-06 12:02:59 +1000 | [diff] [blame] | 851 | return -ENOMEM; |
| 852 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | /* offset overflow? */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 854 | if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff) |
Mike Frysinger | f81cff0 | 2006-12-06 12:02:59 +1000 | [diff] [blame] | 855 | return -EOVERFLOW; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | |
| 857 | if (file) { |
| 858 | /* validate file mapping requests */ |
| 859 | struct address_space *mapping; |
| 860 | |
| 861 | /* files must support mmap */ |
| 862 | if (!file->f_op || !file->f_op->mmap) |
| 863 | return -ENODEV; |
| 864 | |
| 865 | /* work out if what we've got could possibly be shared |
| 866 | * - we support chardevs that provide their own "memory" |
| 867 | * - we support files/blockdevs that are memory backed |
| 868 | */ |
| 869 | mapping = file->f_mapping; |
| 870 | if (!mapping) |
Josef Sipek | e9536ae | 2006-12-08 02:37:21 -0800 | [diff] [blame] | 871 | mapping = file->f_path.dentry->d_inode->i_mapping; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | |
| 873 | capabilities = 0; |
| 874 | if (mapping && mapping->backing_dev_info) |
| 875 | capabilities = mapping->backing_dev_info->capabilities; |
| 876 | |
| 877 | if (!capabilities) { |
| 878 | /* no explicit capabilities set, so assume some |
| 879 | * defaults */ |
Josef Sipek | e9536ae | 2006-12-08 02:37:21 -0800 | [diff] [blame] | 880 | switch (file->f_path.dentry->d_inode->i_mode & S_IFMT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | case S_IFREG: |
| 882 | case S_IFBLK: |
| 883 | capabilities = BDI_CAP_MAP_COPY; |
| 884 | break; |
| 885 | |
| 886 | case S_IFCHR: |
| 887 | capabilities = |
| 888 | BDI_CAP_MAP_DIRECT | |
| 889 | BDI_CAP_READ_MAP | |
| 890 | BDI_CAP_WRITE_MAP; |
| 891 | break; |
| 892 | |
| 893 | default: |
| 894 | return -EINVAL; |
| 895 | } |
| 896 | } |
| 897 | |
| 898 | /* eliminate any capabilities that we can't support on this |
| 899 | * device */ |
| 900 | if (!file->f_op->get_unmapped_area) |
| 901 | capabilities &= ~BDI_CAP_MAP_DIRECT; |
| 902 | if (!file->f_op->read) |
| 903 | capabilities &= ~BDI_CAP_MAP_COPY; |
| 904 | |
| 905 | if (flags & MAP_SHARED) { |
| 906 | /* do checks for writing, appending and locking */ |
| 907 | if ((prot & PROT_WRITE) && |
| 908 | !(file->f_mode & FMODE_WRITE)) |
| 909 | return -EACCES; |
| 910 | |
Josef Sipek | e9536ae | 2006-12-08 02:37:21 -0800 | [diff] [blame] | 911 | if (IS_APPEND(file->f_path.dentry->d_inode) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | (file->f_mode & FMODE_WRITE)) |
| 913 | return -EACCES; |
| 914 | |
Josef Sipek | e9536ae | 2006-12-08 02:37:21 -0800 | [diff] [blame] | 915 | if (locks_verify_locked(file->f_path.dentry->d_inode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | return -EAGAIN; |
| 917 | |
| 918 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) |
| 919 | return -ENODEV; |
| 920 | |
| 921 | if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) || |
| 922 | ((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) || |
| 923 | ((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP)) |
| 924 | ) { |
| 925 | printk("MAP_SHARED not completely supported on !MMU\n"); |
| 926 | return -EINVAL; |
| 927 | } |
| 928 | |
| 929 | /* we mustn't privatise shared mappings */ |
| 930 | capabilities &= ~BDI_CAP_MAP_COPY; |
| 931 | } |
| 932 | else { |
| 933 | /* we're going to read the file into private memory we |
| 934 | * allocate */ |
| 935 | if (!(capabilities & BDI_CAP_MAP_COPY)) |
| 936 | return -ENODEV; |
| 937 | |
| 938 | /* we don't permit a private writable mapping to be |
| 939 | * shared with the backing device */ |
| 940 | if (prot & PROT_WRITE) |
| 941 | capabilities &= ~BDI_CAP_MAP_DIRECT; |
| 942 | } |
| 943 | |
| 944 | /* handle executable mappings and implied executable |
| 945 | * mappings */ |
Josef Sipek | e9536ae | 2006-12-08 02:37:21 -0800 | [diff] [blame] | 946 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | if (prot & PROT_EXEC) |
| 948 | return -EPERM; |
| 949 | } |
| 950 | else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) { |
| 951 | /* handle implication of PROT_EXEC by PROT_READ */ |
| 952 | if (current->personality & READ_IMPLIES_EXEC) { |
| 953 | if (capabilities & BDI_CAP_EXEC_MAP) |
| 954 | prot |= PROT_EXEC; |
| 955 | } |
| 956 | } |
| 957 | else if ((prot & PROT_READ) && |
| 958 | (prot & PROT_EXEC) && |
| 959 | !(capabilities & BDI_CAP_EXEC_MAP) |
| 960 | ) { |
| 961 | /* backing file is not executable, try to copy */ |
| 962 | capabilities &= ~BDI_CAP_MAP_DIRECT; |
| 963 | } |
| 964 | } |
| 965 | else { |
| 966 | /* anonymous mappings are always memory backed and can be |
| 967 | * privately mapped |
| 968 | */ |
| 969 | capabilities = BDI_CAP_MAP_COPY; |
| 970 | |
| 971 | /* handle PROT_EXEC implication by PROT_READ */ |
| 972 | if ((prot & PROT_READ) && |
| 973 | (current->personality & READ_IMPLIES_EXEC)) |
| 974 | prot |= PROT_EXEC; |
| 975 | } |
| 976 | |
| 977 | /* allow the security API to have its say */ |
Eric Paris | ed03218 | 2007-06-28 15:55:21 -0400 | [diff] [blame] | 978 | ret = security_file_mmap(file, reqprot, prot, flags, addr, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | if (ret < 0) |
| 980 | return ret; |
| 981 | |
| 982 | /* looks okay */ |
| 983 | *_capabilities = capabilities; |
| 984 | return 0; |
| 985 | } |
| 986 | |
| 987 | /* |
| 988 | * we've determined that we can make the mapping, now translate what we |
| 989 | * now know into VMA flags |
| 990 | */ |
| 991 | static unsigned long determine_vm_flags(struct file *file, |
| 992 | unsigned long prot, |
| 993 | unsigned long flags, |
| 994 | unsigned long capabilities) |
| 995 | { |
| 996 | unsigned long vm_flags; |
| 997 | |
| 998 | vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags); |
| 999 | vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC; |
| 1000 | /* vm_flags |= mm->def_flags; */ |
| 1001 | |
| 1002 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) { |
| 1003 | /* attempt to share read-only copies of mapped file chunks */ |
| 1004 | if (file && !(prot & PROT_WRITE)) |
| 1005 | vm_flags |= VM_MAYSHARE; |
| 1006 | } |
| 1007 | else { |
| 1008 | /* overlay a shareable mapping on the backing device or inode |
| 1009 | * if possible - used for chardevs, ramfs/tmpfs/shmfs and |
| 1010 | * romfs/cramfs */ |
| 1011 | if (flags & MAP_SHARED) |
| 1012 | vm_flags |= VM_MAYSHARE | VM_SHARED; |
| 1013 | else if ((((vm_flags & capabilities) ^ vm_flags) & BDI_CAP_VMFLAGS) == 0) |
| 1014 | vm_flags |= VM_MAYSHARE; |
| 1015 | } |
| 1016 | |
| 1017 | /* refuse to let anyone share private mappings with this process if |
| 1018 | * it's being traced - otherwise breakpoints set in it may interfere |
| 1019 | * with another untraced process |
| 1020 | */ |
Roland McGrath | fa8e26c | 2008-07-25 19:45:50 -0700 | [diff] [blame] | 1021 | if ((flags & MAP_PRIVATE) && tracehook_expect_breakpoints(current)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | vm_flags &= ~VM_MAYSHARE; |
| 1023 | |
| 1024 | return vm_flags; |
| 1025 | } |
| 1026 | |
| 1027 | /* |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1028 | * set up a shared mapping on a file (the driver or filesystem provides and |
| 1029 | * pins the storage) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1031 | static int do_mmap_shared_file(struct vm_area_struct *vma) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1032 | { |
| 1033 | int ret; |
| 1034 | |
| 1035 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1036 | if (ret == 0) { |
| 1037 | vma->vm_region->vm_top = vma->vm_region->vm_end; |
| 1038 | return ret; |
| 1039 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1040 | if (ret != -ENOSYS) |
| 1041 | return ret; |
| 1042 | |
| 1043 | /* getting an ENOSYS error indicates that direct mmap isn't |
| 1044 | * possible (as opposed to tried but failed) so we'll fall |
| 1045 | * through to making a private copy of the data and mapping |
| 1046 | * that if we can */ |
| 1047 | return -ENODEV; |
| 1048 | } |
| 1049 | |
| 1050 | /* |
| 1051 | * set up a private mapping or an anonymous shared mapping |
| 1052 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1053 | static int do_mmap_private(struct vm_area_struct *vma, |
| 1054 | struct vm_region *region, |
| 1055 | unsigned long len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1056 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1057 | struct page *pages; |
| 1058 | unsigned long total, point, n, rlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | void *base; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1060 | int ret, order; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1061 | |
| 1062 | /* invoke the file's mapping function so that it can keep track of |
| 1063 | * shared mappings on devices or memory |
| 1064 | * - VM_MAYSHARE will be set if it may attempt to share |
| 1065 | */ |
| 1066 | if (vma->vm_file) { |
| 1067 | ret = vma->vm_file->f_op->mmap(vma->vm_file, vma); |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1068 | if (ret == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | /* shouldn't return success if we're not sharing */ |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1070 | BUG_ON(!(vma->vm_flags & VM_MAYSHARE)); |
| 1071 | vma->vm_region->vm_top = vma->vm_region->vm_end; |
| 1072 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1073 | } |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1074 | if (ret != -ENOSYS) |
| 1075 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | |
| 1077 | /* getting an ENOSYS error indicates that direct mmap isn't |
| 1078 | * possible (as opposed to tried but failed) so we'll try to |
| 1079 | * make a private copy of the data and map that instead */ |
| 1080 | } |
| 1081 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1082 | rlen = PAGE_ALIGN(len); |
| 1083 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1084 | /* allocate some memory to hold the mapping |
| 1085 | * - note that this may not return a page-aligned address if the object |
| 1086 | * we're allocating is smaller than a page |
| 1087 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1088 | order = get_order(rlen); |
| 1089 | kdebug("alloc order %d for %lx", order, len); |
| 1090 | |
| 1091 | pages = alloc_pages(GFP_KERNEL, order); |
| 1092 | if (!pages) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | goto enomem; |
| 1094 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1095 | total = 1 << order; |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 1096 | atomic_long_add(total, &mmap_pages_allocated); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1097 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1098 | point = rlen >> PAGE_SHIFT; |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1099 | |
| 1100 | /* we allocated a power-of-2 sized page set, so we may want to trim off |
| 1101 | * the excess */ |
| 1102 | if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) { |
| 1103 | while (total > point) { |
| 1104 | order = ilog2(total - point); |
| 1105 | n = 1 << order; |
| 1106 | kdebug("shave %lu/%lu @%lu", n, total - point, total); |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 1107 | atomic_long_sub(n, &mmap_pages_allocated); |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1108 | total -= n; |
| 1109 | set_page_refcounted(pages + total); |
| 1110 | __free_pages(pages + total, order); |
| 1111 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1112 | } |
| 1113 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1114 | for (point = 1; point < total; point++) |
| 1115 | set_page_refcounted(&pages[point]); |
| 1116 | |
| 1117 | base = page_address(pages); |
| 1118 | region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY; |
| 1119 | region->vm_start = (unsigned long) base; |
| 1120 | region->vm_end = region->vm_start + rlen; |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1121 | region->vm_top = region->vm_start + (total << PAGE_SHIFT); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1122 | |
| 1123 | vma->vm_start = region->vm_start; |
| 1124 | vma->vm_end = region->vm_start + len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1125 | |
| 1126 | if (vma->vm_file) { |
| 1127 | /* read the contents of a file into the copy */ |
| 1128 | mm_segment_t old_fs; |
| 1129 | loff_t fpos; |
| 1130 | |
| 1131 | fpos = vma->vm_pgoff; |
| 1132 | fpos <<= PAGE_SHIFT; |
| 1133 | |
| 1134 | old_fs = get_fs(); |
| 1135 | set_fs(KERNEL_DS); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1136 | ret = vma->vm_file->f_op->read(vma->vm_file, base, rlen, &fpos); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1137 | set_fs(old_fs); |
| 1138 | |
| 1139 | if (ret < 0) |
| 1140 | goto error_free; |
| 1141 | |
| 1142 | /* clear the last little bit */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1143 | if (ret < rlen) |
| 1144 | memset(base + ret, 0, rlen - ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1145 | |
| 1146 | } else { |
| 1147 | /* if it's an anonymous mapping, then just clear it */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1148 | memset(base, 0, rlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1149 | } |
| 1150 | |
| 1151 | return 0; |
| 1152 | |
| 1153 | error_free: |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1154 | free_page_series(region->vm_start, region->vm_end); |
| 1155 | region->vm_start = vma->vm_start = 0; |
| 1156 | region->vm_end = vma->vm_end = 0; |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1157 | region->vm_top = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | return ret; |
| 1159 | |
| 1160 | enomem: |
Greg Ungerer | 05ae6fa | 2009-01-13 17:30:22 +1000 | [diff] [blame] | 1161 | printk("Allocation of length %lu from process %d (%s) failed\n", |
| 1162 | len, current->pid, current->comm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1163 | show_free_areas(); |
| 1164 | return -ENOMEM; |
| 1165 | } |
| 1166 | |
| 1167 | /* |
| 1168 | * handle mapping creation for uClinux |
| 1169 | */ |
| 1170 | unsigned long do_mmap_pgoff(struct file *file, |
| 1171 | unsigned long addr, |
| 1172 | unsigned long len, |
| 1173 | unsigned long prot, |
| 1174 | unsigned long flags, |
| 1175 | unsigned long pgoff) |
| 1176 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1177 | struct vm_area_struct *vma; |
| 1178 | struct vm_region *region; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1179 | struct rb_node *rb; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1180 | unsigned long capabilities, vm_flags, result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | int ret; |
| 1182 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1183 | kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff); |
| 1184 | |
Eric Paris | 7cd9414 | 2007-11-26 18:47:40 -0500 | [diff] [blame] | 1185 | if (!(flags & MAP_FIXED)) |
| 1186 | addr = round_hint_to_min(addr); |
| 1187 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1188 | /* decide whether we should attempt the mapping, and if so what sort of |
| 1189 | * mapping */ |
| 1190 | ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, |
| 1191 | &capabilities); |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1192 | if (ret < 0) { |
| 1193 | kleave(" = %d [val]", ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1194 | return ret; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1195 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1196 | |
| 1197 | /* we've determined that we can make the mapping, now translate what we |
| 1198 | * now know into VMA flags */ |
| 1199 | vm_flags = determine_vm_flags(file, prot, flags, capabilities); |
| 1200 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1201 | /* we're going to need to record the mapping */ |
| 1202 | region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL); |
| 1203 | if (!region) |
| 1204 | goto error_getting_region; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1206 | vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
| 1207 | if (!vma) |
| 1208 | goto error_getting_vma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1209 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1210 | atomic_set(®ion->vm_usage, 1); |
| 1211 | region->vm_flags = vm_flags; |
| 1212 | region->vm_pgoff = pgoff; |
| 1213 | |
| 1214 | INIT_LIST_HEAD(&vma->anon_vma_node); |
| 1215 | vma->vm_flags = vm_flags; |
| 1216 | vma->vm_pgoff = pgoff; |
| 1217 | |
| 1218 | if (file) { |
| 1219 | region->vm_file = file; |
| 1220 | get_file(file); |
| 1221 | vma->vm_file = file; |
| 1222 | get_file(file); |
| 1223 | if (vm_flags & VM_EXECUTABLE) { |
| 1224 | added_exe_file_vma(current->mm); |
| 1225 | vma->vm_mm = current->mm; |
| 1226 | } |
| 1227 | } |
| 1228 | |
| 1229 | down_write(&nommu_region_sem); |
| 1230 | |
| 1231 | /* if we want to share, we need to check for regions created by other |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | * mmap() calls that overlap with our proposed mapping |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1233 | * - we can only share with a superset match on most regular files |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | * - shared mappings on character devices and memory backed files are |
| 1235 | * permitted to overlap inexactly as far as we are concerned for in |
| 1236 | * these cases, sharing is handled in the driver or filesystem rather |
| 1237 | * than here |
| 1238 | */ |
| 1239 | if (vm_flags & VM_MAYSHARE) { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1240 | struct vm_region *pregion; |
| 1241 | unsigned long pglen, rpglen, pgend, rpgend, start; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1243 | pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1244 | pgend = pgoff + pglen; |
David Howells | 165b239 | 2007-03-22 00:11:24 -0800 | [diff] [blame] | 1245 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1246 | for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) { |
| 1247 | pregion = rb_entry(rb, struct vm_region, vm_rb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1248 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1249 | if (!(pregion->vm_flags & VM_MAYSHARE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1250 | continue; |
| 1251 | |
| 1252 | /* search for overlapping mappings on the same file */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1253 | if (pregion->vm_file->f_path.dentry->d_inode != |
| 1254 | file->f_path.dentry->d_inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1255 | continue; |
| 1256 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1257 | if (pregion->vm_pgoff >= pgend) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1258 | continue; |
| 1259 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1260 | rpglen = pregion->vm_end - pregion->vm_start; |
| 1261 | rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 1262 | rpgend = pregion->vm_pgoff + rpglen; |
| 1263 | if (pgoff >= rpgend) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1264 | continue; |
| 1265 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1266 | /* handle inexactly overlapping matches between |
| 1267 | * mappings */ |
| 1268 | if ((pregion->vm_pgoff != pgoff || rpglen != pglen) && |
| 1269 | !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) { |
| 1270 | /* new mapping is not a subset of the region */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1271 | if (!(capabilities & BDI_CAP_MAP_DIRECT)) |
| 1272 | goto sharing_violation; |
| 1273 | continue; |
| 1274 | } |
| 1275 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1276 | /* we've found a region we can share */ |
| 1277 | atomic_inc(&pregion->vm_usage); |
| 1278 | vma->vm_region = pregion; |
| 1279 | start = pregion->vm_start; |
| 1280 | start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT; |
| 1281 | vma->vm_start = start; |
| 1282 | vma->vm_end = start + len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1284 | if (pregion->vm_flags & VM_MAPPED_COPY) { |
| 1285 | kdebug("share copy"); |
| 1286 | vma->vm_flags |= VM_MAPPED_COPY; |
| 1287 | } else { |
| 1288 | kdebug("share mmap"); |
| 1289 | ret = do_mmap_shared_file(vma); |
| 1290 | if (ret < 0) { |
| 1291 | vma->vm_region = NULL; |
| 1292 | vma->vm_start = 0; |
| 1293 | vma->vm_end = 0; |
| 1294 | atomic_dec(&pregion->vm_usage); |
| 1295 | pregion = NULL; |
| 1296 | goto error_just_free; |
| 1297 | } |
| 1298 | } |
| 1299 | fput(region->vm_file); |
| 1300 | kmem_cache_free(vm_region_jar, region); |
| 1301 | region = pregion; |
| 1302 | result = start; |
| 1303 | goto share; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | } |
| 1305 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1306 | /* obtain the address at which to make a shared mapping |
| 1307 | * - this is the hook for quasi-memory character devices to |
| 1308 | * tell us the location of a shared mapping |
| 1309 | */ |
| 1310 | if (file && file->f_op->get_unmapped_area) { |
| 1311 | addr = file->f_op->get_unmapped_area(file, addr, len, |
| 1312 | pgoff, flags); |
| 1313 | if (IS_ERR((void *) addr)) { |
| 1314 | ret = addr; |
| 1315 | if (ret != (unsigned long) -ENOSYS) |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1316 | goto error_just_free; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1317 | |
| 1318 | /* the driver refused to tell us where to site |
| 1319 | * the mapping so we'll have to attempt to copy |
| 1320 | * it */ |
| 1321 | ret = (unsigned long) -ENODEV; |
| 1322 | if (!(capabilities & BDI_CAP_MAP_COPY)) |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1323 | goto error_just_free; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1324 | |
| 1325 | capabilities &= ~BDI_CAP_MAP_DIRECT; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1326 | } else { |
| 1327 | vma->vm_start = region->vm_start = addr; |
| 1328 | vma->vm_end = region->vm_end = addr + len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | } |
| 1330 | } |
| 1331 | } |
| 1332 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1333 | vma->vm_region = region; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | |
| 1335 | /* set up the mapping */ |
| 1336 | if (file && vma->vm_flags & VM_SHARED) |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1337 | ret = do_mmap_shared_file(vma); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1338 | else |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1339 | ret = do_mmap_private(vma, region, len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | if (ret < 0) |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1341 | goto error_put_region; |
| 1342 | |
| 1343 | add_nommu_region(region); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1344 | |
| 1345 | /* okay... we have a mapping; now we have to register it */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1346 | result = vma->vm_start; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1347 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1348 | current->mm->total_vm += len >> PAGE_SHIFT; |
| 1349 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1350 | share: |
| 1351 | add_vma_to_mm(current->mm, vma); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1352 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1353 | up_write(&nommu_region_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1354 | |
| 1355 | if (prot & PROT_EXEC) |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1356 | flush_icache_range(result, result + len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1357 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1358 | kleave(" = %lx", result); |
| 1359 | return result; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1360 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1361 | error_put_region: |
| 1362 | __put_nommu_region(region); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1363 | if (vma) { |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 1364 | if (vma->vm_file) { |
Gavin Lambert | 3fcd03e | 2006-09-30 23:27:01 -0700 | [diff] [blame] | 1365 | fput(vma->vm_file); |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 1366 | if (vma->vm_flags & VM_EXECUTABLE) |
| 1367 | removed_exe_file_vma(vma->vm_mm); |
| 1368 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1369 | kmem_cache_free(vm_area_cachep, vma); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1370 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1371 | kleave(" = %d [pr]", ret); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1372 | return ret; |
| 1373 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1374 | error_just_free: |
| 1375 | up_write(&nommu_region_sem); |
| 1376 | error: |
| 1377 | fput(region->vm_file); |
| 1378 | kmem_cache_free(vm_region_jar, region); |
| 1379 | fput(vma->vm_file); |
| 1380 | if (vma->vm_flags & VM_EXECUTABLE) |
| 1381 | removed_exe_file_vma(vma->vm_mm); |
| 1382 | kmem_cache_free(vm_area_cachep, vma); |
| 1383 | kleave(" = %d", ret); |
| 1384 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1385 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1386 | sharing_violation: |
| 1387 | up_write(&nommu_region_sem); |
| 1388 | printk(KERN_WARNING "Attempt to share mismatched mappings\n"); |
| 1389 | ret = -EINVAL; |
| 1390 | goto error; |
| 1391 | |
| 1392 | error_getting_vma: |
| 1393 | kmem_cache_free(vm_region_jar, region); |
| 1394 | printk(KERN_WARNING "Allocation of vma for %lu byte allocation" |
| 1395 | " from process %d failed\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | len, current->pid); |
| 1397 | show_free_areas(); |
| 1398 | return -ENOMEM; |
| 1399 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1400 | error_getting_region: |
| 1401 | printk(KERN_WARNING "Allocation of vm region for %lu byte allocation" |
| 1402 | " from process %d failed\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1403 | len, current->pid); |
| 1404 | show_free_areas(); |
| 1405 | return -ENOMEM; |
| 1406 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 1407 | EXPORT_SYMBOL(do_mmap_pgoff); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | |
| 1409 | /* |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1410 | * split a vma into two pieces at address 'addr', a new vma is allocated either |
| 1411 | * for the first part or the tail. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1412 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1413 | int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, |
| 1414 | unsigned long addr, int new_below) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1416 | struct vm_area_struct *new; |
| 1417 | struct vm_region *region; |
| 1418 | unsigned long npages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1419 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1420 | kenter(""); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1421 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1422 | /* we're only permitted to split anonymous regions that have a single |
| 1423 | * owner */ |
| 1424 | if (vma->vm_file || |
| 1425 | atomic_read(&vma->vm_region->vm_usage) != 1) |
| 1426 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1427 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1428 | if (mm->map_count >= sysctl_max_map_count) |
| 1429 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1431 | region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL); |
| 1432 | if (!region) |
| 1433 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1434 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1435 | new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL); |
| 1436 | if (!new) { |
| 1437 | kmem_cache_free(vm_region_jar, region); |
| 1438 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1439 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1440 | |
| 1441 | /* most fields are the same, copy all, and then fixup */ |
| 1442 | *new = *vma; |
| 1443 | *region = *vma->vm_region; |
| 1444 | new->vm_region = region; |
| 1445 | |
| 1446 | npages = (addr - vma->vm_start) >> PAGE_SHIFT; |
| 1447 | |
| 1448 | if (new_below) { |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1449 | region->vm_top = region->vm_end = new->vm_end = addr; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1450 | } else { |
| 1451 | region->vm_start = new->vm_start = addr; |
| 1452 | region->vm_pgoff = new->vm_pgoff += npages; |
| 1453 | } |
| 1454 | |
| 1455 | if (new->vm_ops && new->vm_ops->open) |
| 1456 | new->vm_ops->open(new); |
| 1457 | |
| 1458 | delete_vma_from_mm(vma); |
| 1459 | down_write(&nommu_region_sem); |
| 1460 | delete_nommu_region(vma->vm_region); |
| 1461 | if (new_below) { |
| 1462 | vma->vm_region->vm_start = vma->vm_start = addr; |
| 1463 | vma->vm_region->vm_pgoff = vma->vm_pgoff += npages; |
| 1464 | } else { |
| 1465 | vma->vm_region->vm_end = vma->vm_end = addr; |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1466 | vma->vm_region->vm_top = addr; |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1467 | } |
| 1468 | add_nommu_region(vma->vm_region); |
| 1469 | add_nommu_region(new->vm_region); |
| 1470 | up_write(&nommu_region_sem); |
| 1471 | add_vma_to_mm(mm, vma); |
| 1472 | add_vma_to_mm(mm, new); |
| 1473 | return 0; |
| 1474 | } |
| 1475 | |
| 1476 | /* |
| 1477 | * shrink a VMA by removing the specified chunk from either the beginning or |
| 1478 | * the end |
| 1479 | */ |
| 1480 | static int shrink_vma(struct mm_struct *mm, |
| 1481 | struct vm_area_struct *vma, |
| 1482 | unsigned long from, unsigned long to) |
| 1483 | { |
| 1484 | struct vm_region *region; |
| 1485 | |
| 1486 | kenter(""); |
| 1487 | |
| 1488 | /* adjust the VMA's pointers, which may reposition it in the MM's tree |
| 1489 | * and list */ |
| 1490 | delete_vma_from_mm(vma); |
| 1491 | if (from > vma->vm_start) |
| 1492 | vma->vm_end = from; |
| 1493 | else |
| 1494 | vma->vm_start = to; |
| 1495 | add_vma_to_mm(mm, vma); |
| 1496 | |
| 1497 | /* cut the backing region down to size */ |
| 1498 | region = vma->vm_region; |
| 1499 | BUG_ON(atomic_read(®ion->vm_usage) != 1); |
| 1500 | |
| 1501 | down_write(&nommu_region_sem); |
| 1502 | delete_nommu_region(region); |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1503 | if (from > region->vm_start) { |
| 1504 | to = region->vm_top; |
| 1505 | region->vm_top = region->vm_end = from; |
| 1506 | } else { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1507 | region->vm_start = to; |
Paul Mundt | dd8632a | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1508 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1509 | add_nommu_region(region); |
| 1510 | up_write(&nommu_region_sem); |
| 1511 | |
| 1512 | free_page_series(from, to); |
| 1513 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1514 | } |
| 1515 | |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 1516 | /* |
| 1517 | * release a mapping |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1518 | * - under NOMMU conditions the chunk to be unmapped must be backed by a single |
| 1519 | * VMA, though it need not cover the whole VMA |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 1520 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1521 | int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1523 | struct vm_area_struct *vma; |
| 1524 | struct rb_node *rb; |
| 1525 | unsigned long end = start + len; |
| 1526 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1527 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1528 | kenter(",%lx,%zx", start, len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1529 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1530 | if (len == 0) |
| 1531 | return -EINVAL; |
| 1532 | |
| 1533 | /* find the first potentially overlapping VMA */ |
| 1534 | vma = find_vma(mm, start); |
| 1535 | if (!vma) { |
David Howells | 33e5d769 | 2009-04-02 16:56:32 -0700 | [diff] [blame] | 1536 | static int limit = 0; |
| 1537 | if (limit < 5) { |
| 1538 | printk(KERN_WARNING |
| 1539 | "munmap of memory not mmapped by process %d" |
| 1540 | " (%s): 0x%lx-0x%lx\n", |
| 1541 | current->pid, current->comm, |
| 1542 | start, start + len - 1); |
| 1543 | limit++; |
| 1544 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1545 | return -EINVAL; |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 1546 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1547 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1548 | /* we're allowed to split an anonymous VMA but not a file-backed one */ |
| 1549 | if (vma->vm_file) { |
| 1550 | do { |
| 1551 | if (start > vma->vm_start) { |
| 1552 | kleave(" = -EINVAL [miss]"); |
| 1553 | return -EINVAL; |
| 1554 | } |
| 1555 | if (end == vma->vm_end) |
| 1556 | goto erase_whole_vma; |
| 1557 | rb = rb_next(&vma->vm_rb); |
| 1558 | vma = rb_entry(rb, struct vm_area_struct, vm_rb); |
| 1559 | } while (rb); |
| 1560 | kleave(" = -EINVAL [split file]"); |
| 1561 | return -EINVAL; |
| 1562 | } else { |
| 1563 | /* the chunk must be a subset of the VMA found */ |
| 1564 | if (start == vma->vm_start && end == vma->vm_end) |
| 1565 | goto erase_whole_vma; |
| 1566 | if (start < vma->vm_start || end > vma->vm_end) { |
| 1567 | kleave(" = -EINVAL [superset]"); |
| 1568 | return -EINVAL; |
| 1569 | } |
| 1570 | if (start & ~PAGE_MASK) { |
| 1571 | kleave(" = -EINVAL [unaligned start]"); |
| 1572 | return -EINVAL; |
| 1573 | } |
| 1574 | if (end != vma->vm_end && end & ~PAGE_MASK) { |
| 1575 | kleave(" = -EINVAL [unaligned split]"); |
| 1576 | return -EINVAL; |
| 1577 | } |
| 1578 | if (start != vma->vm_start && end != vma->vm_end) { |
| 1579 | ret = split_vma(mm, vma, start, 1); |
| 1580 | if (ret < 0) { |
| 1581 | kleave(" = %d [split]", ret); |
| 1582 | return ret; |
| 1583 | } |
| 1584 | } |
| 1585 | return shrink_vma(mm, vma, start, end); |
| 1586 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1587 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1588 | erase_whole_vma: |
| 1589 | delete_vma_from_mm(vma); |
| 1590 | delete_vma(mm, vma); |
| 1591 | kleave(" = 0"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1592 | return 0; |
| 1593 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 1594 | EXPORT_SYMBOL(do_munmap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1595 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 1596 | SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 1597 | { |
| 1598 | int ret; |
| 1599 | struct mm_struct *mm = current->mm; |
| 1600 | |
| 1601 | down_write(&mm->mmap_sem); |
| 1602 | ret = do_munmap(mm, addr, len); |
| 1603 | up_write(&mm->mmap_sem); |
| 1604 | return ret; |
| 1605 | } |
| 1606 | |
| 1607 | /* |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1608 | * release all the mappings made in a process's VM space |
David Howells | 3034097 | 2006-09-27 01:50:20 -0700 | [diff] [blame] | 1609 | */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1610 | void exit_mmap(struct mm_struct *mm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1611 | { |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1612 | struct vm_area_struct *vma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1613 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1614 | if (!mm) |
| 1615 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1616 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1617 | kenter(""); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1618 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1619 | mm->total_vm = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1620 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1621 | while ((vma = mm->mmap)) { |
| 1622 | mm->mmap = vma->vm_next; |
| 1623 | delete_vma_from_mm(vma); |
| 1624 | delete_vma(mm, vma); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1625 | } |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1626 | |
| 1627 | kleave(""); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1628 | } |
| 1629 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1630 | unsigned long do_brk(unsigned long addr, unsigned long len) |
| 1631 | { |
| 1632 | return -ENOMEM; |
| 1633 | } |
| 1634 | |
| 1635 | /* |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1636 | * expand (or shrink) an existing mapping, potentially moving it at the same |
| 1637 | * time (controlled by the MREMAP_MAYMOVE flag and available VM space) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1638 | * |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1639 | * under NOMMU conditions, we only permit changing a mapping's size, and only |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1640 | * as long as it stays within the region allocated by do_mmap_private() and the |
| 1641 | * block is not shareable |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1642 | * |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1643 | * MREMAP_FIXED is not supported under NOMMU conditions |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1644 | */ |
| 1645 | unsigned long do_mremap(unsigned long addr, |
| 1646 | unsigned long old_len, unsigned long new_len, |
| 1647 | unsigned long flags, unsigned long new_addr) |
| 1648 | { |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1649 | struct vm_area_struct *vma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1650 | |
| 1651 | /* insanity checks first */ |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1652 | if (old_len == 0 || new_len == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1653 | return (unsigned long) -EINVAL; |
| 1654 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1655 | if (addr & ~PAGE_MASK) |
| 1656 | return -EINVAL; |
| 1657 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1658 | if (flags & MREMAP_FIXED && new_addr != addr) |
| 1659 | return (unsigned long) -EINVAL; |
| 1660 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1661 | vma = find_vma_exact(current->mm, addr, old_len); |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1662 | if (!vma) |
| 1663 | return (unsigned long) -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1664 | |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1665 | if (vma->vm_end != vma->vm_start + old_len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1666 | return (unsigned long) -EFAULT; |
| 1667 | |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1668 | if (vma->vm_flags & VM_MAYSHARE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1669 | return (unsigned long) -EPERM; |
| 1670 | |
David Howells | 8feae13 | 2009-01-08 12:04:47 +0000 | [diff] [blame] | 1671 | if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1672 | return (unsigned long) -ENOMEM; |
| 1673 | |
| 1674 | /* all checks complete - do it */ |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1675 | vma->vm_end = vma->vm_start + new_len; |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1676 | return vma->vm_start; |
| 1677 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 1678 | EXPORT_SYMBOL(do_mremap); |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1679 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 1680 | SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, |
| 1681 | unsigned long, new_len, unsigned long, flags, |
| 1682 | unsigned long, new_addr) |
David Howells | 6fa5f80 | 2006-09-27 01:50:21 -0700 | [diff] [blame] | 1683 | { |
| 1684 | unsigned long ret; |
| 1685 | |
| 1686 | down_write(¤t->mm->mmap_sem); |
| 1687 | ret = do_mremap(addr, old_len, new_len, flags, new_addr); |
| 1688 | up_write(¤t->mm->mmap_sem); |
| 1689 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1690 | } |
| 1691 | |
Linus Torvalds | 6aab341 | 2005-11-28 14:34:23 -0800 | [diff] [blame] | 1692 | struct page *follow_page(struct vm_area_struct *vma, unsigned long address, |
Hugh Dickins | deceb6c | 2005-10-29 18:16:33 -0700 | [diff] [blame] | 1693 | unsigned int foll_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1694 | { |
| 1695 | return NULL; |
| 1696 | } |
| 1697 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1698 | int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, |
| 1699 | unsigned long to, unsigned long size, pgprot_t prot) |
| 1700 | { |
Greg Ungerer | 66aa2b4 | 2005-09-12 11:18:10 +1000 | [diff] [blame] | 1701 | vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; |
| 1702 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1703 | } |
Luke Yang | 22c4af4 | 2006-07-14 00:24:09 -0700 | [diff] [blame] | 1704 | EXPORT_SYMBOL(remap_pfn_range); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1705 | |
Paul Mundt | f905bc4 | 2008-02-04 22:29:59 -0800 | [diff] [blame] | 1706 | int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, |
| 1707 | unsigned long pgoff) |
| 1708 | { |
| 1709 | unsigned int size = vma->vm_end - vma->vm_start; |
| 1710 | |
| 1711 | if (!(vma->vm_flags & VM_USERMAP)) |
| 1712 | return -EINVAL; |
| 1713 | |
| 1714 | vma->vm_start = (unsigned long)(addr + (pgoff << PAGE_SHIFT)); |
| 1715 | vma->vm_end = vma->vm_start + size; |
| 1716 | |
| 1717 | return 0; |
| 1718 | } |
| 1719 | EXPORT_SYMBOL(remap_vmalloc_range); |
| 1720 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1721 | void swap_unplug_io_fn(struct backing_dev_info *bdi, struct page *page) |
| 1722 | { |
| 1723 | } |
| 1724 | |
| 1725 | unsigned long arch_get_unmapped_area(struct file *file, unsigned long addr, |
| 1726 | unsigned long len, unsigned long pgoff, unsigned long flags) |
| 1727 | { |
| 1728 | return -ENOMEM; |
| 1729 | } |
| 1730 | |
Wolfgang Wander | 1363c3c | 2005-06-21 17:14:49 -0700 | [diff] [blame] | 1731 | void arch_unmap_area(struct mm_struct *mm, unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1732 | { |
| 1733 | } |
| 1734 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1735 | void unmap_mapping_range(struct address_space *mapping, |
| 1736 | loff_t const holebegin, loff_t const holelen, |
| 1737 | int even_cows) |
| 1738 | { |
| 1739 | } |
Luke Yang | 22c4af4 | 2006-07-14 00:24:09 -0700 | [diff] [blame] | 1740 | EXPORT_SYMBOL(unmap_mapping_range); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | |
| 1742 | /* |
David Howells | d56e03c | 2007-03-22 00:11:23 -0800 | [diff] [blame] | 1743 | * ask for an unmapped area at which to create a mapping on a file |
| 1744 | */ |
| 1745 | unsigned long get_unmapped_area(struct file *file, unsigned long addr, |
| 1746 | unsigned long len, unsigned long pgoff, |
| 1747 | unsigned long flags) |
| 1748 | { |
| 1749 | unsigned long (*get_area)(struct file *, unsigned long, unsigned long, |
| 1750 | unsigned long, unsigned long); |
| 1751 | |
| 1752 | get_area = current->mm->get_unmapped_area; |
| 1753 | if (file && file->f_op && file->f_op->get_unmapped_area) |
| 1754 | get_area = file->f_op->get_unmapped_area; |
| 1755 | |
| 1756 | if (!get_area) |
| 1757 | return -ENOSYS; |
| 1758 | |
| 1759 | return get_area(file, addr, len, pgoff, flags); |
| 1760 | } |
David Howells | d56e03c | 2007-03-22 00:11:23 -0800 | [diff] [blame] | 1761 | EXPORT_SYMBOL(get_unmapped_area); |
| 1762 | |
| 1763 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1764 | * Check that a process has enough memory to allocate a new virtual |
| 1765 | * mapping. 0 means there is enough memory for the allocation to |
| 1766 | * succeed and -ENOMEM implies there is not. |
| 1767 | * |
| 1768 | * We currently support three overcommit policies, which are set via the |
| 1769 | * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting |
| 1770 | * |
| 1771 | * Strict overcommit modes added 2002 Feb 26 by Alan Cox. |
| 1772 | * Additional code 2002 Jul 20 by Robert Love. |
| 1773 | * |
| 1774 | * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise. |
| 1775 | * |
| 1776 | * Note this is a helper function intended to be used by LSMs which |
| 1777 | * wish to use this logic. |
| 1778 | */ |
Alan Cox | 34b4e4a | 2007-08-22 14:01:28 -0700 | [diff] [blame] | 1779 | int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1780 | { |
| 1781 | unsigned long free, allowed; |
| 1782 | |
| 1783 | vm_acct_memory(pages); |
| 1784 | |
| 1785 | /* |
| 1786 | * Sometimes we want to use more memory than we have |
| 1787 | */ |
| 1788 | if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS) |
| 1789 | return 0; |
| 1790 | |
| 1791 | if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) { |
| 1792 | unsigned long n; |
| 1793 | |
Christoph Lameter | 347ce43 | 2006-06-30 01:55:35 -0700 | [diff] [blame] | 1794 | free = global_page_state(NR_FILE_PAGES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1795 | free += nr_swap_pages; |
| 1796 | |
| 1797 | /* |
| 1798 | * Any slabs which are created with the |
| 1799 | * SLAB_RECLAIM_ACCOUNT flag claim to have contents |
| 1800 | * which are reclaimable, under pressure. The dentry |
| 1801 | * cache and most inode caches should fall into this |
| 1802 | */ |
Christoph Lameter | 972d1a7 | 2006-09-25 23:31:51 -0700 | [diff] [blame] | 1803 | free += global_page_state(NR_SLAB_RECLAIMABLE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1804 | |
| 1805 | /* |
| 1806 | * Leave the last 3% for root |
| 1807 | */ |
| 1808 | if (!cap_sys_admin) |
| 1809 | free -= free / 32; |
| 1810 | |
| 1811 | if (free > pages) |
| 1812 | return 0; |
| 1813 | |
| 1814 | /* |
| 1815 | * nr_free_pages() is very expensive on large systems, |
| 1816 | * only call if we're about to fail. |
| 1817 | */ |
| 1818 | n = nr_free_pages(); |
Hideo AOKI | d5ddc79 | 2006-04-10 22:53:01 -0700 | [diff] [blame] | 1819 | |
| 1820 | /* |
| 1821 | * Leave reserved pages. The pages are not for anonymous pages. |
| 1822 | */ |
| 1823 | if (n <= totalreserve_pages) |
| 1824 | goto error; |
| 1825 | else |
| 1826 | n -= totalreserve_pages; |
| 1827 | |
| 1828 | /* |
| 1829 | * Leave the last 3% for root |
| 1830 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1831 | if (!cap_sys_admin) |
| 1832 | n -= n / 32; |
| 1833 | free += n; |
| 1834 | |
| 1835 | if (free > pages) |
| 1836 | return 0; |
Hideo AOKI | d5ddc79 | 2006-04-10 22:53:01 -0700 | [diff] [blame] | 1837 | |
| 1838 | goto error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1839 | } |
| 1840 | |
| 1841 | allowed = totalram_pages * sysctl_overcommit_ratio / 100; |
| 1842 | /* |
| 1843 | * Leave the last 3% for root |
| 1844 | */ |
| 1845 | if (!cap_sys_admin) |
| 1846 | allowed -= allowed / 32; |
| 1847 | allowed += total_swap_pages; |
| 1848 | |
| 1849 | /* Don't let a single process grow too big: |
| 1850 | leave 3% of the size of this process for other processes */ |
Alan Cox | 731572d | 2008-10-29 14:01:20 -0700 | [diff] [blame] | 1851 | if (mm) |
| 1852 | allowed -= mm->total_vm / 32; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1853 | |
KOSAKI Motohiro | 00a62ce | 2009-04-30 15:08:51 -0700 | [diff] [blame] | 1854 | if (percpu_counter_read_positive(&vm_committed_as) < allowed) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1855 | return 0; |
KOSAKI Motohiro | 00a62ce | 2009-04-30 15:08:51 -0700 | [diff] [blame] | 1856 | |
Hideo AOKI | d5ddc79 | 2006-04-10 22:53:01 -0700 | [diff] [blame] | 1857 | error: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1858 | vm_unacct_memory(pages); |
| 1859 | |
| 1860 | return -ENOMEM; |
| 1861 | } |
| 1862 | |
| 1863 | int in_gate_area_no_task(unsigned long addr) |
| 1864 | { |
| 1865 | return 0; |
| 1866 | } |
David Howells | b0e1519 | 2006-01-06 00:11:42 -0800 | [diff] [blame] | 1867 | |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1868 | int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
David Howells | b0e1519 | 2006-01-06 00:11:42 -0800 | [diff] [blame] | 1869 | { |
| 1870 | BUG(); |
Nick Piggin | d0217ac | 2007-07-19 01:47:03 -0700 | [diff] [blame] | 1871 | return 0; |
David Howells | b0e1519 | 2006-01-06 00:11:42 -0800 | [diff] [blame] | 1872 | } |
Paul Mundt | b507317 | 2007-07-21 04:37:25 -0700 | [diff] [blame] | 1873 | EXPORT_SYMBOL(filemap_fault); |
David Howells | 0ec76a1 | 2006-09-27 01:50:15 -0700 | [diff] [blame] | 1874 | |
| 1875 | /* |
| 1876 | * Access another process' address space. |
| 1877 | * - source/target buffer must be kernel space |
| 1878 | */ |
| 1879 | int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write) |
| 1880 | { |
David Howells | 0ec76a1 | 2006-09-27 01:50:15 -0700 | [diff] [blame] | 1881 | struct vm_area_struct *vma; |
| 1882 | struct mm_struct *mm; |
| 1883 | |
| 1884 | if (addr + len < addr) |
| 1885 | return 0; |
| 1886 | |
| 1887 | mm = get_task_mm(tsk); |
| 1888 | if (!mm) |
| 1889 | return 0; |
| 1890 | |
| 1891 | down_read(&mm->mmap_sem); |
| 1892 | |
| 1893 | /* the access must start within one of the target process's mappings */ |
David Howells | 0159b14 | 2006-09-27 01:50:16 -0700 | [diff] [blame] | 1894 | vma = find_vma(mm, addr); |
| 1895 | if (vma) { |
David Howells | 0ec76a1 | 2006-09-27 01:50:15 -0700 | [diff] [blame] | 1896 | /* don't overrun this mapping */ |
| 1897 | if (addr + len >= vma->vm_end) |
| 1898 | len = vma->vm_end - addr; |
| 1899 | |
| 1900 | /* only read or write mappings where it is permitted */ |
David Howells | d00c7b99 | 2006-09-27 01:50:19 -0700 | [diff] [blame] | 1901 | if (write && vma->vm_flags & VM_MAYWRITE) |
David Howells | 0ec76a1 | 2006-09-27 01:50:15 -0700 | [diff] [blame] | 1902 | len -= copy_to_user((void *) addr, buf, len); |
David Howells | d00c7b99 | 2006-09-27 01:50:19 -0700 | [diff] [blame] | 1903 | else if (!write && vma->vm_flags & VM_MAYREAD) |
David Howells | 0ec76a1 | 2006-09-27 01:50:15 -0700 | [diff] [blame] | 1904 | len -= copy_from_user(buf, (void *) addr, len); |
| 1905 | else |
| 1906 | len = 0; |
| 1907 | } else { |
| 1908 | len = 0; |
| 1909 | } |
| 1910 | |
| 1911 | up_read(&mm->mmap_sem); |
| 1912 | mmput(mm); |
| 1913 | return len; |
| 1914 | } |