Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/exec.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * #!-checking implemented by tytso. |
| 9 | */ |
| 10 | /* |
| 11 | * Demand-loading implemented 01.12.91 - no need to read anything but |
| 12 | * the header into memory. The inode of the executable is put into |
| 13 | * "current->executable", and page faults do the actual loading. Clean. |
| 14 | * |
| 15 | * Once more I can proudly say that linux stood up to being changed: it |
| 16 | * was less than 2 hours work to get demand-loading completely implemented. |
| 17 | * |
| 18 | * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead, |
| 19 | * current->executable is only used by the procfs. This allows a dispatch |
| 20 | * table to check for several different types of binary formats. We keep |
| 21 | * trying until we recognize the file or we run out of supported binary |
| 22 | * formats. |
| 23 | */ |
| 24 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/slab.h> |
| 26 | #include <linux/file.h> |
Al Viro | 9f3acc3 | 2008-04-24 07:44:08 -0400 | [diff] [blame] | 27 | #include <linux/fdtable.h> |
Hugh Dickins | ba92a43 | 2008-07-25 01:45:43 -0700 | [diff] [blame] | 28 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <linux/stat.h> |
| 30 | #include <linux/fcntl.h> |
Hugh Dickins | ba92a43 | 2008-07-25 01:45:43 -0700 | [diff] [blame] | 31 | #include <linux/swap.h> |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 32 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | #include <linux/init.h> |
Hugh Dickins | ca5b172 | 2008-07-28 15:46:18 -0700 | [diff] [blame] | 34 | #include <linux/pagemap.h> |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 35 | #include <linux/perf_event.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <linux/highmem.h> |
| 37 | #include <linux/spinlock.h> |
| 38 | #include <linux/key.h> |
| 39 | #include <linux/personality.h> |
| 40 | #include <linux/binfmts.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | #include <linux/utsname.h> |
Sukadev Bhattiprolu | 84d7378 | 2006-12-08 02:38:01 -0800 | [diff] [blame] | 42 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #include <linux/module.h> |
| 44 | #include <linux/namei.h> |
| 45 | #include <linux/proc_fs.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | #include <linux/mount.h> |
| 47 | #include <linux/security.h> |
| 48 | #include <linux/syscalls.h> |
Jay Lan | 8f0ab51 | 2006-09-30 23:28:59 -0700 | [diff] [blame] | 49 | #include <linux/tsacct_kern.h> |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 50 | #include <linux/cn_proc.h> |
Al Viro | 473ae30 | 2006-04-26 14:04:08 -0400 | [diff] [blame] | 51 | #include <linux/audit.h> |
Roland McGrath | 6341c39 | 2008-07-25 19:45:44 -0700 | [diff] [blame] | 52 | #include <linux/tracehook.h> |
Johannes Berg | 5f4123b | 2008-07-09 10:28:40 +0200 | [diff] [blame] | 53 | #include <linux/kmod.h> |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 54 | #include <linux/fsnotify.h> |
Al Viro | 5ad4e53 | 2009-03-29 19:50:06 -0400 | [diff] [blame] | 55 | #include <linux/fs_struct.h> |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 56 | #include <linux/pipe_fs_i.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
| 58 | #include <asm/uaccess.h> |
| 59 | #include <asm/mmu_context.h> |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 60 | #include <asm/tlb.h> |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 61 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | int core_uses_pid; |
Dan Aloni | 71ce92f | 2007-05-16 22:11:16 -0700 | [diff] [blame] | 64 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 65 | unsigned int core_pipe_limit; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 66 | int suid_dumpable = 0; |
| 67 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
| 69 | |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 70 | static LIST_HEAD(formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | static DEFINE_RWLOCK(binfmt_lock); |
| 72 | |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 73 | int __register_binfmt(struct linux_binfmt * fmt, int insert) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | if (!fmt) |
| 76 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | write_lock(&binfmt_lock); |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 78 | insert ? list_add(&fmt->lh, &formats) : |
| 79 | list_add_tail(&fmt->lh, &formats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | write_unlock(&binfmt_lock); |
| 81 | return 0; |
| 82 | } |
| 83 | |
Ivan Kokshaysky | 74641f5 | 2009-04-30 15:08:49 -0700 | [diff] [blame] | 84 | EXPORT_SYMBOL(__register_binfmt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | |
Alexey Dobriyan | f6b450d | 2007-10-16 23:26:04 -0700 | [diff] [blame] | 86 | void unregister_binfmt(struct linux_binfmt * fmt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | write_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 89 | list_del(&fmt->lh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | write_unlock(&binfmt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | } |
| 92 | |
| 93 | EXPORT_SYMBOL(unregister_binfmt); |
| 94 | |
| 95 | static inline void put_binfmt(struct linux_binfmt * fmt) |
| 96 | { |
| 97 | module_put(fmt->module); |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * Note that a shared library must be both readable and executable due to |
| 102 | * security reasons. |
| 103 | * |
| 104 | * Also note that we take the address to load from from the file itself. |
| 105 | */ |
Heiko Carstens | 1e7bfb2 | 2009-01-14 14:14:29 +0100 | [diff] [blame] | 106 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | { |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 108 | struct file *file; |
Al Viro | 964bd18 | 2008-07-26 03:33:14 -0400 | [diff] [blame] | 109 | char *tmp = getname(library); |
| 110 | int error = PTR_ERR(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 112 | if (IS_ERR(tmp)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | goto out; |
| 114 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 115 | file = do_filp_open(AT_FDCWD, tmp, |
| 116 | O_LARGEFILE | O_RDONLY | FMODE_EXEC, 0, |
| 117 | MAY_READ | MAY_EXEC | MAY_OPEN); |
| 118 | putname(tmp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | error = PTR_ERR(file); |
| 120 | if (IS_ERR(file)) |
| 121 | goto out; |
| 122 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 123 | error = -EINVAL; |
| 124 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
| 125 | goto exit; |
| 126 | |
| 127 | error = -EACCES; |
| 128 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 129 | goto exit; |
| 130 | |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 131 | fsnotify_open(file->f_path.dentry); |
| 132 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | error = -ENOEXEC; |
| 134 | if(file->f_op) { |
| 135 | struct linux_binfmt * fmt; |
| 136 | |
| 137 | read_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 138 | list_for_each_entry(fmt, &formats, lh) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | if (!fmt->load_shlib) |
| 140 | continue; |
| 141 | if (!try_module_get(fmt->module)) |
| 142 | continue; |
| 143 | read_unlock(&binfmt_lock); |
| 144 | error = fmt->load_shlib(file); |
| 145 | read_lock(&binfmt_lock); |
| 146 | put_binfmt(fmt); |
| 147 | if (error != -ENOEXEC) |
| 148 | break; |
| 149 | } |
| 150 | read_unlock(&binfmt_lock); |
| 151 | } |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 152 | exit: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | fput(file); |
| 154 | out: |
| 155 | return error; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | } |
| 157 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 158 | #ifdef CONFIG_MMU |
| 159 | |
| 160 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 161 | int write) |
| 162 | { |
| 163 | struct page *page; |
| 164 | int ret; |
| 165 | |
| 166 | #ifdef CONFIG_STACK_GROWSUP |
| 167 | if (write) { |
| 168 | ret = expand_stack_downwards(bprm->vma, pos); |
| 169 | if (ret < 0) |
| 170 | return NULL; |
| 171 | } |
| 172 | #endif |
| 173 | ret = get_user_pages(current, bprm->mm, pos, |
| 174 | 1, write, 1, &page, NULL); |
| 175 | if (ret <= 0) |
| 176 | return NULL; |
| 177 | |
| 178 | if (write) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 179 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 180 | struct rlimit *rlim; |
| 181 | |
| 182 | /* |
| 183 | * We've historically supported up to 32 pages (ARG_MAX) |
| 184 | * of argument strings even with small stacks |
| 185 | */ |
| 186 | if (size <= ARG_MAX) |
| 187 | return page; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 188 | |
| 189 | /* |
| 190 | * Limit to 1/4-th the stack size for the argv+env strings. |
| 191 | * This ensures that: |
| 192 | * - the remaining binfmt code will not run out of stack space, |
| 193 | * - the program will have a reasonable amount of stack left |
| 194 | * to work from. |
| 195 | */ |
Linus Torvalds | a64e715 | 2008-03-03 10:12:14 -0800 | [diff] [blame] | 196 | rlim = current->signal->rlim; |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 197 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 198 | put_page(page); |
| 199 | return NULL; |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | return page; |
| 204 | } |
| 205 | |
| 206 | static void put_arg_page(struct page *page) |
| 207 | { |
| 208 | put_page(page); |
| 209 | } |
| 210 | |
| 211 | static void free_arg_page(struct linux_binprm *bprm, int i) |
| 212 | { |
| 213 | } |
| 214 | |
| 215 | static void free_arg_pages(struct linux_binprm *bprm) |
| 216 | { |
| 217 | } |
| 218 | |
| 219 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 220 | struct page *page) |
| 221 | { |
| 222 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); |
| 223 | } |
| 224 | |
| 225 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 226 | { |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 227 | int err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 228 | struct vm_area_struct *vma = NULL; |
| 229 | struct mm_struct *mm = bprm->mm; |
| 230 | |
| 231 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
| 232 | if (!vma) |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 233 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 234 | |
| 235 | down_write(&mm->mmap_sem); |
| 236 | vma->vm_mm = mm; |
| 237 | |
| 238 | /* |
| 239 | * Place the stack at the largest stack address the architecture |
| 240 | * supports. Later, we'll move this to an appropriate place. We don't |
| 241 | * use STACK_TOP because that can depend on attributes which aren't |
| 242 | * configured yet. |
| 243 | */ |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 244 | BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 245 | vma->vm_end = STACK_TOP_MAX; |
| 246 | vma->vm_start = vma->vm_end - PAGE_SIZE; |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 247 | vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
Coly Li | 3ed75eb | 2007-10-18 23:39:15 -0700 | [diff] [blame] | 248 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 249 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 250 | err = insert_vm_struct(mm, vma); |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 251 | if (err) |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 252 | goto err; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 253 | |
| 254 | mm->stack_vm = mm->total_vm = 1; |
| 255 | up_write(&mm->mmap_sem); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 256 | bprm->p = vma->vm_end - sizeof(void *); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 257 | return 0; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 258 | err: |
Luiz Fernando N. Capitulino | eaccbfa | 2009-01-06 14:40:44 -0800 | [diff] [blame] | 259 | up_write(&mm->mmap_sem); |
| 260 | bprm->vma = NULL; |
| 261 | kmem_cache_free(vm_area_cachep, vma); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 262 | return err; |
| 263 | } |
| 264 | |
| 265 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 266 | { |
| 267 | return len <= MAX_ARG_STRLEN; |
| 268 | } |
| 269 | |
| 270 | #else |
| 271 | |
| 272 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 273 | int write) |
| 274 | { |
| 275 | struct page *page; |
| 276 | |
| 277 | page = bprm->page[pos / PAGE_SIZE]; |
| 278 | if (!page && write) { |
| 279 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); |
| 280 | if (!page) |
| 281 | return NULL; |
| 282 | bprm->page[pos / PAGE_SIZE] = page; |
| 283 | } |
| 284 | |
| 285 | return page; |
| 286 | } |
| 287 | |
| 288 | static void put_arg_page(struct page *page) |
| 289 | { |
| 290 | } |
| 291 | |
| 292 | static void free_arg_page(struct linux_binprm *bprm, int i) |
| 293 | { |
| 294 | if (bprm->page[i]) { |
| 295 | __free_page(bprm->page[i]); |
| 296 | bprm->page[i] = NULL; |
| 297 | } |
| 298 | } |
| 299 | |
| 300 | static void free_arg_pages(struct linux_binprm *bprm) |
| 301 | { |
| 302 | int i; |
| 303 | |
| 304 | for (i = 0; i < MAX_ARG_PAGES; i++) |
| 305 | free_arg_page(bprm, i); |
| 306 | } |
| 307 | |
| 308 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, |
| 309 | struct page *page) |
| 310 | { |
| 311 | } |
| 312 | |
| 313 | static int __bprm_mm_init(struct linux_binprm *bprm) |
| 314 | { |
| 315 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); |
| 316 | return 0; |
| 317 | } |
| 318 | |
| 319 | static bool valid_arg_len(struct linux_binprm *bprm, long len) |
| 320 | { |
| 321 | return len <= bprm->p; |
| 322 | } |
| 323 | |
| 324 | #endif /* CONFIG_MMU */ |
| 325 | |
| 326 | /* |
| 327 | * Create a new mm_struct and populate it with a temporary stack |
| 328 | * vm_area_struct. We don't have enough context at this point to set the stack |
| 329 | * flags, permissions, and offset, so we use temporary values. We'll update |
| 330 | * them later in setup_arg_pages(). |
| 331 | */ |
| 332 | int bprm_mm_init(struct linux_binprm *bprm) |
| 333 | { |
| 334 | int err; |
| 335 | struct mm_struct *mm = NULL; |
| 336 | |
| 337 | bprm->mm = mm = mm_alloc(); |
| 338 | err = -ENOMEM; |
| 339 | if (!mm) |
| 340 | goto err; |
| 341 | |
| 342 | err = init_new_context(current, mm); |
| 343 | if (err) |
| 344 | goto err; |
| 345 | |
| 346 | err = __bprm_mm_init(bprm); |
| 347 | if (err) |
| 348 | goto err; |
| 349 | |
| 350 | return 0; |
| 351 | |
| 352 | err: |
| 353 | if (mm) { |
| 354 | bprm->mm = NULL; |
| 355 | mmdrop(mm); |
| 356 | } |
| 357 | |
| 358 | return err; |
| 359 | } |
| 360 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | /* |
| 362 | * count() counts the number of strings in array ARGV. |
| 363 | */ |
| 364 | static int count(char __user * __user * argv, int max) |
| 365 | { |
| 366 | int i = 0; |
| 367 | |
| 368 | if (argv != NULL) { |
| 369 | for (;;) { |
| 370 | char __user * p; |
| 371 | |
| 372 | if (get_user(p, argv)) |
| 373 | return -EFAULT; |
| 374 | if (!p) |
| 375 | break; |
| 376 | argv++; |
Jason Baron | 362e666 | 2008-10-15 22:01:52 -0700 | [diff] [blame] | 377 | if (i++ >= max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | return -E2BIG; |
| 379 | cond_resched(); |
| 380 | } |
| 381 | } |
| 382 | return i; |
| 383 | } |
| 384 | |
| 385 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 386 | * 'copy_strings()' copies argument/environment strings from the old |
| 387 | * processes's memory to the new process's stack. The call to get_user_pages() |
| 388 | * ensures the destination page is created and not swapped out. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | */ |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 390 | static int copy_strings(int argc, char __user * __user * argv, |
| 391 | struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | { |
| 393 | struct page *kmapped_page = NULL; |
| 394 | char *kaddr = NULL; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 395 | unsigned long kpos = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | int ret; |
| 397 | |
| 398 | while (argc-- > 0) { |
| 399 | char __user *str; |
| 400 | int len; |
| 401 | unsigned long pos; |
| 402 | |
| 403 | if (get_user(str, argv+argc) || |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 404 | !(len = strnlen_user(str, MAX_ARG_STRLEN))) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | ret = -EFAULT; |
| 406 | goto out; |
| 407 | } |
| 408 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 409 | if (!valid_arg_len(bprm, len)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | ret = -E2BIG; |
| 411 | goto out; |
| 412 | } |
| 413 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 414 | /* We're going to work our way backwords. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | pos = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 416 | str += len; |
| 417 | bprm->p -= len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | |
| 419 | while (len > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | int offset, bytes_to_copy; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | |
| 422 | offset = pos % PAGE_SIZE; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 423 | if (offset == 0) |
| 424 | offset = PAGE_SIZE; |
| 425 | |
| 426 | bytes_to_copy = offset; |
| 427 | if (bytes_to_copy > len) |
| 428 | bytes_to_copy = len; |
| 429 | |
| 430 | offset -= bytes_to_copy; |
| 431 | pos -= bytes_to_copy; |
| 432 | str -= bytes_to_copy; |
| 433 | len -= bytes_to_copy; |
| 434 | |
| 435 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { |
| 436 | struct page *page; |
| 437 | |
| 438 | page = get_arg_page(bprm, pos, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | if (!page) { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 440 | ret = -E2BIG; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | goto out; |
| 442 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 444 | if (kmapped_page) { |
| 445 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 447 | put_arg_page(kmapped_page); |
| 448 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | kmapped_page = page; |
| 450 | kaddr = kmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 451 | kpos = pos & PAGE_MASK; |
| 452 | flush_arg_page(bprm, kpos, kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | } |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 454 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | ret = -EFAULT; |
| 456 | goto out; |
| 457 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | } |
| 459 | } |
| 460 | ret = 0; |
| 461 | out: |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 462 | if (kmapped_page) { |
| 463 | flush_kernel_dcache_page(kmapped_page); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | kunmap(kmapped_page); |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 465 | put_arg_page(kmapped_page); |
| 466 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | return ret; |
| 468 | } |
| 469 | |
| 470 | /* |
| 471 | * Like copy_strings, but get argv and its values from kernel memory. |
| 472 | */ |
| 473 | int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) |
| 474 | { |
| 475 | int r; |
| 476 | mm_segment_t oldfs = get_fs(); |
| 477 | set_fs(KERNEL_DS); |
| 478 | r = copy_strings(argc, (char __user * __user *)argv, bprm); |
| 479 | set_fs(oldfs); |
| 480 | return r; |
| 481 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | EXPORT_SYMBOL(copy_strings_kernel); |
| 483 | |
| 484 | #ifdef CONFIG_MMU |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 485 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 486 | /* |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 487 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
| 488 | * the binfmt code determines where the new stack should reside, we shift it to |
| 489 | * its final location. The process proceeds as follows: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | * |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 491 | * 1) Use shift to calculate the new vma endpoints. |
| 492 | * 2) Extend vma to cover both the old and new ranges. This ensures the |
| 493 | * arguments passed to subsequent functions are consistent. |
| 494 | * 3) Move vma's page tables to the new range. |
| 495 | * 4) Free up any cleared pgd range. |
| 496 | * 5) Shrink the vma to cover only the new range. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 498 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | { |
| 500 | struct mm_struct *mm = vma->vm_mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 501 | unsigned long old_start = vma->vm_start; |
| 502 | unsigned long old_end = vma->vm_end; |
| 503 | unsigned long length = old_end - old_start; |
| 504 | unsigned long new_start = old_start - shift; |
| 505 | unsigned long new_end = old_end - shift; |
| 506 | struct mmu_gather *tlb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 507 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 508 | BUG_ON(new_start > new_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 510 | /* |
| 511 | * ensure there are no vmas between where we want to go |
| 512 | * and where we are |
| 513 | */ |
| 514 | if (vma != find_vma(mm, new_start)) |
| 515 | return -EFAULT; |
| 516 | |
| 517 | /* |
| 518 | * cover the whole range: [new_start, old_end) |
| 519 | */ |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 520 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
| 521 | return -ENOMEM; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 522 | |
| 523 | /* |
| 524 | * move the page tables downwards, on failure we rely on |
| 525 | * process cleanup to remove whatever mess we made. |
| 526 | */ |
| 527 | if (length != move_page_tables(vma, old_start, |
| 528 | vma, new_start, length)) |
| 529 | return -ENOMEM; |
| 530 | |
| 531 | lru_add_drain(); |
| 532 | tlb = tlb_gather_mmu(mm, 0); |
| 533 | if (new_end > old_start) { |
| 534 | /* |
| 535 | * when the old and new regions overlap clear from new_end. |
| 536 | */ |
Jan Beulich | 42b7772 | 2008-07-23 21:27:10 -0700 | [diff] [blame] | 537 | free_pgd_range(tlb, new_end, old_end, new_end, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 538 | vma->vm_next ? vma->vm_next->vm_start : 0); |
| 539 | } else { |
| 540 | /* |
| 541 | * otherwise, clean from old_start; this is done to not touch |
| 542 | * the address space in [new_end, old_start) some architectures |
| 543 | * have constraints on va-space that make this illegal (IA64) - |
| 544 | * for the others its just a little faster. |
| 545 | */ |
Jan Beulich | 42b7772 | 2008-07-23 21:27:10 -0700 | [diff] [blame] | 546 | free_pgd_range(tlb, old_start, old_end, new_end, |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 547 | vma->vm_next ? vma->vm_next->vm_start : 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | } |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 549 | tlb_finish_mmu(tlb, new_end, old_end); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 551 | /* |
Rik van Riel | 5beb493 | 2010-03-05 13:42:07 -0800 | [diff] [blame] | 552 | * Shrink the vma to just the new range. Always succeeds. |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 553 | */ |
| 554 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); |
| 555 | |
| 556 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | } |
| 558 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 559 | /* |
| 560 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, |
| 561 | * the stack is optionally relocated, and some extra space is added. |
| 562 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | int setup_arg_pages(struct linux_binprm *bprm, |
| 564 | unsigned long stack_top, |
| 565 | int executable_stack) |
| 566 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 567 | unsigned long ret; |
| 568 | unsigned long stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | struct mm_struct *mm = current->mm; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 570 | struct vm_area_struct *vma = bprm->vma; |
| 571 | struct vm_area_struct *prev = NULL; |
| 572 | unsigned long vm_flags; |
| 573 | unsigned long stack_base; |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 574 | unsigned long stack_size; |
| 575 | unsigned long stack_expand; |
| 576 | unsigned long rlim_stack; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | |
| 578 | #ifdef CONFIG_STACK_GROWSUP |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | /* Limit stack size to 1GB */ |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 580 | stack_base = rlimit_max(RLIMIT_STACK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | if (stack_base > (1 << 30)) |
| 582 | stack_base = 1 << 30; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 584 | /* Make sure we didn't let the argument array grow too large. */ |
| 585 | if (vma->vm_end - vma->vm_start > stack_base) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 586 | return -ENOMEM; |
| 587 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 588 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
| 589 | |
| 590 | stack_shift = vma->vm_start - stack_base; |
| 591 | mm->arg_start = bprm->p - stack_shift; |
| 592 | bprm->p = vma->vm_end - stack_shift; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | #else |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 594 | stack_top = arch_align_stack(stack_top); |
| 595 | stack_top = PAGE_ALIGN(stack_top); |
| 596 | stack_shift = vma->vm_end - stack_top; |
| 597 | |
| 598 | bprm->p -= stack_shift; |
| 599 | mm->arg_start = bprm->p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | #endif |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 601 | |
| 602 | if (bprm->loader) |
| 603 | bprm->loader -= stack_shift; |
| 604 | bprm->exec -= stack_shift; |
| 605 | |
| 606 | down_write(&mm->mmap_sem); |
Hugh Dickins | 96a8e13 | 2008-07-10 21:19:20 +0100 | [diff] [blame] | 607 | vm_flags = VM_STACK_FLAGS; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 608 | |
| 609 | /* |
| 610 | * Adjust stack execute permissions; explicitly enable for |
| 611 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone |
| 612 | * (arch default) otherwise. |
| 613 | */ |
| 614 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) |
| 615 | vm_flags |= VM_EXEC; |
| 616 | else if (executable_stack == EXSTACK_DISABLE_X) |
| 617 | vm_flags &= ~VM_EXEC; |
| 618 | vm_flags |= mm->def_flags; |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 619 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 620 | |
| 621 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, |
| 622 | vm_flags); |
| 623 | if (ret) |
| 624 | goto out_unlock; |
| 625 | BUG_ON(prev != vma); |
| 626 | |
| 627 | /* Move stack pages down in memory. */ |
| 628 | if (stack_shift) { |
| 629 | ret = shift_arg_pages(vma, stack_shift); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 630 | if (ret) |
| 631 | goto out_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | } |
| 633 | |
Mel Gorman | a8bef8ff | 2010-05-24 14:32:24 -0700 | [diff] [blame] | 634 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
| 635 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; |
| 636 | |
Michael Neuling | 5ef097d | 2010-03-05 13:42:57 -0800 | [diff] [blame] | 637 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 638 | stack_size = vma->vm_end - vma->vm_start; |
| 639 | /* |
| 640 | * Align this down to a page boundary as expand_stack |
| 641 | * will align it up. |
| 642 | */ |
| 643 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 644 | #ifdef CONFIG_STACK_GROWSUP |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 645 | if (stack_size + stack_expand > rlim_stack) |
| 646 | stack_base = vma->vm_start + rlim_stack; |
| 647 | else |
| 648 | stack_base = vma->vm_end + stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 649 | #else |
Michael Neuling | 803bf5e | 2010-02-10 13:56:42 -0800 | [diff] [blame] | 650 | if (stack_size + stack_expand > rlim_stack) |
| 651 | stack_base = vma->vm_end - rlim_stack; |
| 652 | else |
| 653 | stack_base = vma->vm_start - stack_expand; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 654 | #endif |
Eric B Munson | 3af9e85 | 2010-05-18 15:30:49 +0100 | [diff] [blame] | 655 | current->mm->start_stack = bprm->p; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 656 | ret = expand_stack(vma, stack_base); |
| 657 | if (ret) |
| 658 | ret = -EFAULT; |
| 659 | |
| 660 | out_unlock: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | up_write(&mm->mmap_sem); |
Anton Blanchard | fc63cf2 | 2009-11-11 14:26:48 -0800 | [diff] [blame] | 662 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | EXPORT_SYMBOL(setup_arg_pages); |
| 665 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | #endif /* CONFIG_MMU */ |
| 667 | |
| 668 | struct file *open_exec(const char *name) |
| 669 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | struct file *file; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 671 | int err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 673 | file = do_filp_open(AT_FDCWD, name, |
| 674 | O_LARGEFILE | O_RDONLY | FMODE_EXEC, 0, |
| 675 | MAY_EXEC | MAY_OPEN); |
| 676 | if (IS_ERR(file)) |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 677 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 679 | err = -EACCES; |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 680 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
| 681 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 682 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 683 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 684 | goto exit; |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 685 | |
Eric Paris | 6110e3a | 2008-12-17 13:53:20 -0500 | [diff] [blame] | 686 | fsnotify_open(file->f_path.dentry); |
| 687 | |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 688 | err = deny_write_access(file); |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 689 | if (err) |
| 690 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 692 | out: |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 693 | return file; |
| 694 | |
Al Viro | 6e8341a | 2009-04-06 11:16:22 -0400 | [diff] [blame] | 695 | exit: |
| 696 | fput(file); |
Christoph Hellwig | e56b6a5 | 2008-05-19 07:53:34 +0200 | [diff] [blame] | 697 | return ERR_PTR(err); |
| 698 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 699 | EXPORT_SYMBOL(open_exec); |
| 700 | |
Mimi Zohar | 6777d77 | 2009-08-21 14:32:48 -0400 | [diff] [blame] | 701 | int kernel_read(struct file *file, loff_t offset, |
| 702 | char *addr, unsigned long count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | { |
| 704 | mm_segment_t old_fs; |
| 705 | loff_t pos = offset; |
| 706 | int result; |
| 707 | |
| 708 | old_fs = get_fs(); |
| 709 | set_fs(get_ds()); |
| 710 | /* The cast to a user pointer is valid due to the set_fs() */ |
| 711 | result = vfs_read(file, (void __user *)addr, count, &pos); |
| 712 | set_fs(old_fs); |
| 713 | return result; |
| 714 | } |
| 715 | |
| 716 | EXPORT_SYMBOL(kernel_read); |
| 717 | |
| 718 | static int exec_mmap(struct mm_struct *mm) |
| 719 | { |
| 720 | struct task_struct *tsk; |
| 721 | struct mm_struct * old_mm, *active_mm; |
| 722 | |
| 723 | /* Notify parent that we're no longer interested in the old VM */ |
| 724 | tsk = current; |
| 725 | old_mm = current->mm; |
KAMEZAWA Hiroyuki | 34e5523 | 2010-03-05 13:41:40 -0800 | [diff] [blame] | 726 | sync_mm_rss(tsk, old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 727 | mm_release(tsk, old_mm); |
| 728 | |
| 729 | if (old_mm) { |
| 730 | /* |
| 731 | * Make sure that if there is a core dump in progress |
| 732 | * for the old mm, we get out and die instead of going |
| 733 | * through with the exec. We must hold mmap_sem around |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 734 | * checking core_state and changing tsk->mm. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 735 | */ |
| 736 | down_read(&old_mm->mmap_sem); |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 737 | if (unlikely(old_mm->core_state)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 738 | up_read(&old_mm->mmap_sem); |
| 739 | return -EINTR; |
| 740 | } |
| 741 | } |
| 742 | task_lock(tsk); |
| 743 | active_mm = tsk->active_mm; |
| 744 | tsk->mm = mm; |
| 745 | tsk->active_mm = mm; |
| 746 | activate_mm(active_mm, mm); |
| 747 | task_unlock(tsk); |
| 748 | arch_pick_mmap_layout(mm); |
| 749 | if (old_mm) { |
| 750 | up_read(&old_mm->mmap_sem); |
Eric Sesterhenn | 7dddb12 | 2006-04-01 01:13:38 +0200 | [diff] [blame] | 751 | BUG_ON(active_mm != old_mm); |
Balbir Singh | 31a78f2 | 2008-09-28 23:09:31 +0100 | [diff] [blame] | 752 | mm_update_next_owner(old_mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | mmput(old_mm); |
| 754 | return 0; |
| 755 | } |
| 756 | mmdrop(active_mm); |
| 757 | return 0; |
| 758 | } |
| 759 | |
| 760 | /* |
| 761 | * This function makes sure the current process has its own signal table, |
| 762 | * so that flush_signal_handlers can later reset the handlers without |
| 763 | * disturbing other processes. (Other processes might share the signal |
| 764 | * table via the CLONE_SIGHAND option to clone().) |
| 765 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 766 | static int de_thread(struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | { |
| 768 | struct signal_struct *sig = tsk->signal; |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 769 | struct sighand_struct *oldsighand = tsk->sighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | spinlock_t *lock = &oldsighand->siglock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 772 | if (thread_group_empty(tsk)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | goto no_thread_group; |
| 774 | |
| 775 | /* |
| 776 | * Kill all other threads in the thread group. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 778 | spin_lock_irq(lock); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 779 | if (signal_group_exit(sig)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 780 | /* |
| 781 | * Another group action in progress, just |
| 782 | * return so that the signal is processed. |
| 783 | */ |
| 784 | spin_unlock_irq(lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 785 | return -EAGAIN; |
| 786 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | |
Oleg Nesterov | d344193 | 2010-05-26 14:43:11 -0700 | [diff] [blame] | 788 | sig->group_exit_task = tsk; |
| 789 | sig->notify_count = zap_other_threads(tsk); |
| 790 | if (!thread_group_leader(tsk)) |
| 791 | sig->notify_count--; |
| 792 | |
| 793 | while (sig->notify_count) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | __set_current_state(TASK_UNINTERRUPTIBLE); |
| 795 | spin_unlock_irq(lock); |
| 796 | schedule(); |
| 797 | spin_lock_irq(lock); |
| 798 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 799 | spin_unlock_irq(lock); |
| 800 | |
| 801 | /* |
| 802 | * At this point all other threads have exited, all we have to |
| 803 | * do is to wait for the thread group leader to become inactive, |
| 804 | * and to assume its PID: |
| 805 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 806 | if (!thread_group_leader(tsk)) { |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 807 | struct task_struct *leader = tsk->group_leader; |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 808 | |
Oleg Nesterov | 2800d8d | 2008-04-30 00:53:12 -0700 | [diff] [blame] | 809 | sig->notify_count = -1; /* for exit_notify() */ |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 810 | for (;;) { |
| 811 | write_lock_irq(&tasklist_lock); |
| 812 | if (likely(leader->exit_state)) |
| 813 | break; |
| 814 | __set_current_state(TASK_UNINTERRUPTIBLE); |
| 815 | write_unlock_irq(&tasklist_lock); |
| 816 | schedule(); |
| 817 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 819 | /* |
| 820 | * The only record we have of the real-time age of a |
| 821 | * process, regardless of execs it's done, is start_time. |
| 822 | * All the past CPU time is accumulated in signal_struct |
| 823 | * from sister threads now dead. But in this non-leader |
| 824 | * exec, nothing survives from the original leader thread, |
| 825 | * whose birth marks the true age of this process now. |
| 826 | * When we take on its identity by switching to its PID, we |
| 827 | * also take its birthdate (always earlier than our own). |
| 828 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 829 | tsk->start_time = leader->start_time; |
Roland McGrath | f5e9028 | 2006-04-10 22:54:16 -0700 | [diff] [blame] | 830 | |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 831 | BUG_ON(!same_thread_group(leader, tsk)); |
| 832 | BUG_ON(has_group_leader_pid(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 833 | /* |
| 834 | * An exec() starts a new thread group with the |
| 835 | * TGID of the previous thread group. Rehash the |
| 836 | * two threads with a switched PID, and release |
| 837 | * the former thread group leader: |
| 838 | */ |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 839 | |
| 840 | /* Become a process group leader with the old leader's pid. |
Eric W. Biederman | c18258c | 2006-09-27 01:51:06 -0700 | [diff] [blame] | 841 | * The old leader becomes a thread of the this thread group. |
| 842 | * Note: The old leader also uses this pid until release_task |
Eric W. Biederman | d73d652 | 2006-03-28 16:11:03 -0800 | [diff] [blame] | 843 | * is called. Odd but simple and correct. |
| 844 | */ |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 845 | detach_pid(tsk, PIDTYPE_PID); |
| 846 | tsk->pid = leader->pid; |
Sukadev Bhattiprolu | 3743ca0 | 2007-10-18 23:39:51 -0700 | [diff] [blame] | 847 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 848 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
| 849 | transfer_pid(leader, tsk, PIDTYPE_SID); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 850 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 851 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
Oleg Nesterov | 9cd80bb | 2009-12-17 15:27:15 -0800 | [diff] [blame] | 852 | list_replace_init(&leader->sibling, &tsk->sibling); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 854 | tsk->group_leader = tsk; |
| 855 | leader->group_leader = tsk; |
Eric W. Biederman | de12a78 | 2006-04-10 17:16:49 -0600 | [diff] [blame] | 856 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 857 | tsk->exit_signal = SIGCHLD; |
Oleg Nesterov | 962b564 | 2005-11-23 13:37:43 -0800 | [diff] [blame] | 858 | |
| 859 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); |
| 860 | leader->exit_state = EXIT_DEAD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 861 | write_unlock_irq(&tasklist_lock); |
Oleg Nesterov | 8187926 | 2008-12-01 14:18:16 -0800 | [diff] [blame] | 862 | |
| 863 | release_task(leader); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 864 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 865 | |
Oleg Nesterov | 6db840f | 2007-10-16 23:27:23 -0700 | [diff] [blame] | 866 | sig->group_exit_task = NULL; |
| 867 | sig->notify_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | |
| 869 | no_thread_group: |
Jiri Pirko | 1f10206 | 2009-09-22 16:44:10 -0700 | [diff] [blame] | 870 | if (current->mm) |
| 871 | setmax_mm_hiwater_rss(&sig->maxrss, current->mm); |
| 872 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 873 | exit_itimers(sig); |
Oleg Nesterov | cbaffba | 2008-05-26 20:55:42 +0400 | [diff] [blame] | 874 | flush_itimer_signals(); |
Oleg Nesterov | 329f7db | 2005-11-07 21:12:43 +0300 | [diff] [blame] | 875 | |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 876 | if (atomic_read(&oldsighand->count) != 1) { |
| 877 | struct sighand_struct *newsighand; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | /* |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 879 | * This ->sighand is shared with the CLONE_SIGHAND |
| 880 | * but not CLONE_THREAD task, switch to the new one. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 881 | */ |
Oleg Nesterov | b2c903b | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 882 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
| 883 | if (!newsighand) |
| 884 | return -ENOMEM; |
| 885 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 886 | atomic_set(&newsighand->count, 1); |
| 887 | memcpy(newsighand->action, oldsighand->action, |
| 888 | sizeof(newsighand->action)); |
| 889 | |
| 890 | write_lock_irq(&tasklist_lock); |
| 891 | spin_lock(&oldsighand->siglock); |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 892 | rcu_assign_pointer(tsk->sighand, newsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 893 | spin_unlock(&oldsighand->siglock); |
| 894 | write_unlock_irq(&tasklist_lock); |
| 895 | |
Davide Libenzi | fba2afa | 2007-05-10 22:23:13 -0700 | [diff] [blame] | 896 | __cleanup_sighand(oldsighand); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | } |
| 898 | |
Eric W. Biederman | aafe6c2 | 2006-09-27 01:51:13 -0700 | [diff] [blame] | 899 | BUG_ON(!thread_group_leader(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 900 | return 0; |
| 901 | } |
Oleg Nesterov | 0840a90 | 2007-10-16 23:27:22 -0700 | [diff] [blame] | 902 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | /* |
| 904 | * These functions flushes out all traces of the currently running executable |
| 905 | * so that a new one can be started |
| 906 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 907 | static void flush_old_files(struct files_struct * files) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | { |
| 909 | long j = -1; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 910 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | |
| 912 | spin_lock(&files->file_lock); |
| 913 | for (;;) { |
| 914 | unsigned long set, i; |
| 915 | |
| 916 | j++; |
| 917 | i = j * __NFDBITS; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 918 | fdt = files_fdtable(files); |
Vadim Lobanov | bbea9f6 | 2006-12-10 02:21:12 -0800 | [diff] [blame] | 919 | if (i >= fdt->max_fds) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 920 | break; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 921 | set = fdt->close_on_exec->fds_bits[j]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 922 | if (!set) |
| 923 | continue; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 924 | fdt->close_on_exec->fds_bits[j] = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 925 | spin_unlock(&files->file_lock); |
| 926 | for ( ; set ; i++,set >>= 1) { |
| 927 | if (set & 1) { |
| 928 | sys_close(i); |
| 929 | } |
| 930 | } |
| 931 | spin_lock(&files->file_lock); |
| 932 | |
| 933 | } |
| 934 | spin_unlock(&files->file_lock); |
| 935 | } |
| 936 | |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 937 | char *get_task_comm(char *buf, struct task_struct *tsk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 938 | { |
| 939 | /* buf must be at least sizeof(tsk->comm) in size */ |
| 940 | task_lock(tsk); |
| 941 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); |
| 942 | task_unlock(tsk); |
Andrew Morton | 59714d6 | 2008-02-04 22:27:21 -0800 | [diff] [blame] | 943 | return buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 944 | } |
| 945 | |
| 946 | void set_task_comm(struct task_struct *tsk, char *buf) |
| 947 | { |
| 948 | task_lock(tsk); |
john stultz | 4614a696b | 2009-12-14 18:00:05 -0800 | [diff] [blame] | 949 | |
| 950 | /* |
| 951 | * Threads may access current->comm without holding |
| 952 | * the task lock, so write the string carefully. |
| 953 | * Readers without a lock may see incomplete new |
| 954 | * names but are safe from non-terminating string reads. |
| 955 | */ |
| 956 | memset(tsk->comm, 0, TASK_COMM_LEN); |
| 957 | wmb(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 958 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
| 959 | task_unlock(tsk); |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 960 | perf_event_comm(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 961 | } |
| 962 | |
| 963 | int flush_old_exec(struct linux_binprm * bprm) |
| 964 | { |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 965 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | |
| 967 | /* |
| 968 | * Make sure we have a private signal table and that |
| 969 | * we are unassociated from the previous thread group. |
| 970 | */ |
| 971 | retval = de_thread(current); |
| 972 | if (retval) |
| 973 | goto out; |
| 974 | |
Matt Helsley | 925d1c4 | 2008-04-29 01:01:36 -0700 | [diff] [blame] | 975 | set_mm_exe_file(bprm->mm, bprm->file); |
| 976 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 977 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | * Release all of the old mmap stuff |
| 979 | */ |
| 980 | retval = exec_mmap(bprm->mm); |
| 981 | if (retval) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 982 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | |
| 984 | bprm->mm = NULL; /* We're using it now */ |
Linus Torvalds | 7ab02af | 2010-02-02 12:37:44 -0800 | [diff] [blame] | 985 | |
| 986 | current->flags &= ~PF_RANDOMIZE; |
| 987 | flush_thread(); |
| 988 | current->personality &= ~bprm->per_clear; |
| 989 | |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 990 | return 0; |
| 991 | |
| 992 | out: |
| 993 | return retval; |
| 994 | } |
| 995 | EXPORT_SYMBOL(flush_old_exec); |
| 996 | |
| 997 | void setup_new_exec(struct linux_binprm * bprm) |
| 998 | { |
| 999 | int i, ch; |
| 1000 | char * name; |
| 1001 | char tcomm[sizeof(current->comm)]; |
| 1002 | |
| 1003 | arch_pick_mmap_layout(current->mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | |
| 1005 | /* This is the point of no return */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1006 | current->sas_ss_sp = current->sas_ss_size = 0; |
| 1007 | |
David Howells | da9592e | 2008-11-14 10:39:05 +1100 | [diff] [blame] | 1008 | if (current_euid() == current_uid() && current_egid() == current_gid()) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1009 | set_dumpable(current->mm, 1); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1010 | else |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1011 | set_dumpable(current->mm, suid_dumpable); |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1012 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1013 | name = bprm->filename; |
Paolo 'Blaisorblade' Giarrusso | 3677209 | 2005-05-05 16:16:12 -0700 | [diff] [blame] | 1014 | |
| 1015 | /* Copies the binary name from after last slash */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | for (i=0; (ch = *(name++)) != '\0';) { |
| 1017 | if (ch == '/') |
Paolo 'Blaisorblade' Giarrusso | 3677209 | 2005-05-05 16:16:12 -0700 | [diff] [blame] | 1018 | i = 0; /* overwrite what we wrote */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1019 | else |
| 1020 | if (i < (sizeof(tcomm) - 1)) |
| 1021 | tcomm[i++] = ch; |
| 1022 | } |
| 1023 | tcomm[i] = '\0'; |
| 1024 | set_task_comm(current, tcomm); |
| 1025 | |
Benjamin Herrenschmidt | 0551fbd | 2006-02-28 16:59:19 -0800 | [diff] [blame] | 1026 | /* Set the new mm task size. We have to do that late because it may |
| 1027 | * depend on TIF_32BIT which is only updated in flush_thread() on |
| 1028 | * some architectures like powerpc |
| 1029 | */ |
| 1030 | current->mm->task_size = TASK_SIZE; |
| 1031 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1032 | /* install the new credentials */ |
| 1033 | if (bprm->cred->uid != current_euid() || |
| 1034 | bprm->cred->gid != current_egid()) { |
Marcel Holtmann | d2d56c5 | 2007-08-17 21:47:58 +0200 | [diff] [blame] | 1035 | current->pdeath_signal = 0; |
| 1036 | } else if (file_permission(bprm->file, MAY_READ) || |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1037 | bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) { |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1038 | set_dumpable(current->mm, suid_dumpable); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | } |
| 1040 | |
Ingo Molnar | f65cb45 | 2008-12-16 13:40:44 +0100 | [diff] [blame] | 1041 | /* |
| 1042 | * Flush performance counters when crossing a |
| 1043 | * security domain: |
| 1044 | */ |
| 1045 | if (!get_dumpable(current->mm)) |
Ingo Molnar | cdd6c48 | 2009-09-21 12:02:48 +0200 | [diff] [blame] | 1046 | perf_event_exit_task(current); |
Ingo Molnar | f65cb45 | 2008-12-16 13:40:44 +0100 | [diff] [blame] | 1047 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | /* An exec changes our domain. We are no longer part of the thread |
| 1049 | group */ |
| 1050 | |
| 1051 | current->self_exec_id++; |
| 1052 | |
| 1053 | flush_signal_handlers(current, 0); |
| 1054 | flush_old_files(current->files); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1055 | } |
Linus Torvalds | 221af7f | 2010-01-28 22:14:42 -0800 | [diff] [blame] | 1056 | EXPORT_SYMBOL(setup_new_exec); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1057 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1058 | /* |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1059 | * Prepare credentials and lock ->cred_guard_mutex. |
| 1060 | * install_exec_creds() commits the new creds and drops the lock. |
| 1061 | * Or, if exec fails before, free_bprm() should release ->cred and |
| 1062 | * and unlock. |
| 1063 | */ |
| 1064 | int prepare_bprm_creds(struct linux_binprm *bprm) |
| 1065 | { |
| 1066 | if (mutex_lock_interruptible(¤t->cred_guard_mutex)) |
| 1067 | return -ERESTARTNOINTR; |
| 1068 | |
| 1069 | bprm->cred = prepare_exec_creds(); |
| 1070 | if (likely(bprm->cred)) |
| 1071 | return 0; |
| 1072 | |
| 1073 | mutex_unlock(¤t->cred_guard_mutex); |
| 1074 | return -ENOMEM; |
| 1075 | } |
| 1076 | |
| 1077 | void free_bprm(struct linux_binprm *bprm) |
| 1078 | { |
| 1079 | free_arg_pages(bprm); |
| 1080 | if (bprm->cred) { |
| 1081 | mutex_unlock(¤t->cred_guard_mutex); |
| 1082 | abort_creds(bprm->cred); |
| 1083 | } |
| 1084 | kfree(bprm); |
| 1085 | } |
| 1086 | |
| 1087 | /* |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1088 | * install the new credentials for this executable |
| 1089 | */ |
| 1090 | void install_exec_creds(struct linux_binprm *bprm) |
| 1091 | { |
| 1092 | security_bprm_committing_creds(bprm); |
| 1093 | |
| 1094 | commit_creds(bprm->cred); |
| 1095 | bprm->cred = NULL; |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1096 | /* |
| 1097 | * cred_guard_mutex must be held at least to this point to prevent |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1098 | * ptrace_attach() from altering our determination of the task's |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1099 | * credentials; any time after this it may be unlocked. |
| 1100 | */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1101 | security_bprm_committed_creds(bprm); |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1102 | mutex_unlock(¤t->cred_guard_mutex); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1103 | } |
| 1104 | EXPORT_SYMBOL(install_exec_creds); |
| 1105 | |
| 1106 | /* |
| 1107 | * determine how safe it is to execute the proposed program |
David Howells | 5e751e9 | 2009-05-08 13:55:22 +0100 | [diff] [blame] | 1108 | * - the caller must hold current->cred_guard_mutex to protect against |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1109 | * PTRACE_ATTACH |
| 1110 | */ |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1111 | int check_unsafe_exec(struct linux_binprm *bprm) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1112 | { |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1113 | struct task_struct *p = current, *t; |
Al Viro | f1191b5 | 2009-03-30 07:35:18 -0400 | [diff] [blame] | 1114 | unsigned n_fs; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1115 | int res = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1116 | |
| 1117 | bprm->unsafe = tracehook_unsafe_exec(p); |
| 1118 | |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1119 | n_fs = 1; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1120 | write_lock(&p->fs->lock); |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1121 | rcu_read_lock(); |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1122 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
| 1123 | if (t->fs == p->fs) |
| 1124 | n_fs++; |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1125 | } |
Oleg Nesterov | 437f7fd | 2009-04-24 01:02:45 +0200 | [diff] [blame] | 1126 | rcu_read_unlock(); |
David Howells | 0bf2f3a | 2009-02-06 11:45:46 +0000 | [diff] [blame] | 1127 | |
Al Viro | f1191b5 | 2009-03-30 07:35:18 -0400 | [diff] [blame] | 1128 | if (p->fs->users > n_fs) { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1129 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1130 | } else { |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1131 | res = -EAGAIN; |
| 1132 | if (!p->fs->in_exec) { |
| 1133 | p->fs->in_exec = 1; |
| 1134 | res = 1; |
| 1135 | } |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1136 | } |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1137 | write_unlock(&p->fs->lock); |
| 1138 | |
| 1139 | return res; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1140 | } |
| 1141 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1142 | /* |
| 1143 | * Fill the binprm structure from the inode. |
| 1144 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1145 | * |
| 1146 | * This may be called multiple times for binary chains (scripts for example). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1147 | */ |
| 1148 | int prepare_binprm(struct linux_binprm *bprm) |
| 1149 | { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1150 | umode_t mode; |
Josef "Jeff" Sipek | 0f7fc9e | 2006-12-08 02:36:35 -0800 | [diff] [blame] | 1151 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1152 | int retval; |
| 1153 | |
| 1154 | mode = inode->i_mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1155 | if (bprm->file->f_op == NULL) |
| 1156 | return -EACCES; |
| 1157 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1158 | /* clear any previous set[ug]id data from a previous binary */ |
| 1159 | bprm->cred->euid = current_euid(); |
| 1160 | bprm->cred->egid = current_egid(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1161 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1162 | if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1163 | /* Set-uid? */ |
| 1164 | if (mode & S_ISUID) { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1165 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1166 | bprm->cred->euid = inode->i_uid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1167 | } |
| 1168 | |
| 1169 | /* Set-gid? */ |
| 1170 | /* |
| 1171 | * If setgid is set but no group execute bit then this |
| 1172 | * is a candidate for mandatory locking, not a setgid |
| 1173 | * executable. |
| 1174 | */ |
| 1175 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1176 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
| 1177 | bprm->cred->egid = inode->i_gid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1178 | } |
| 1179 | } |
| 1180 | |
| 1181 | /* fill in binprm security blob */ |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1182 | retval = security_bprm_set_creds(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1183 | if (retval) |
| 1184 | return retval; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1185 | bprm->cred_prepared = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1187 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
| 1188 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | } |
| 1190 | |
| 1191 | EXPORT_SYMBOL(prepare_binprm); |
| 1192 | |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1193 | /* |
| 1194 | * Arguments are '\0' separated strings found at the location bprm->p |
| 1195 | * points to; chop off the first by relocating brpm->p to right after |
| 1196 | * the first '\0' encountered. |
| 1197 | */ |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1198 | int remove_arg_zero(struct linux_binprm *bprm) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1199 | { |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1200 | int ret = 0; |
| 1201 | unsigned long offset; |
| 1202 | char *kaddr; |
| 1203 | struct page *page; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1204 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1205 | if (!bprm->argc) |
| 1206 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1207 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1208 | do { |
| 1209 | offset = bprm->p & ~PAGE_MASK; |
| 1210 | page = get_arg_page(bprm, bprm->p, 0); |
| 1211 | if (!page) { |
| 1212 | ret = -EFAULT; |
| 1213 | goto out; |
| 1214 | } |
| 1215 | kaddr = kmap_atomic(page, KM_USER0); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1216 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1217 | for (; offset < PAGE_SIZE && kaddr[offset]; |
| 1218 | offset++, bprm->p++) |
| 1219 | ; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1220 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1221 | kunmap_atomic(kaddr, KM_USER0); |
| 1222 | put_arg_page(page); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1223 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1224 | if (offset == PAGE_SIZE) |
| 1225 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); |
| 1226 | } while (offset == PAGE_SIZE); |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1227 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1228 | bprm->p++; |
| 1229 | bprm->argc--; |
| 1230 | ret = 0; |
Nick Piggin | 4fc75ff | 2007-05-08 00:25:16 -0700 | [diff] [blame] | 1231 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1232 | out: |
| 1233 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1234 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1235 | EXPORT_SYMBOL(remove_arg_zero); |
| 1236 | |
| 1237 | /* |
| 1238 | * cycle the list of binary formats handler, until one recognizes the image |
| 1239 | */ |
| 1240 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) |
| 1241 | { |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1242 | unsigned int depth = bprm->recursion_depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1243 | int try,retval; |
| 1244 | struct linux_binfmt *fmt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1245 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1246 | retval = security_bprm_check(bprm); |
| 1247 | if (retval) |
| 1248 | return retval; |
| 1249 | |
| 1250 | /* kernel module loader fixup */ |
| 1251 | /* so we don't try to load run modprobe in kernel space. */ |
| 1252 | set_fs(USER_DS); |
Al Viro | 473ae30 | 2006-04-26 14:04:08 -0400 | [diff] [blame] | 1253 | |
| 1254 | retval = audit_bprm(bprm); |
| 1255 | if (retval) |
| 1256 | return retval; |
| 1257 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1258 | retval = -ENOENT; |
| 1259 | for (try=0; try<2; try++) { |
| 1260 | read_lock(&binfmt_lock); |
Alexey Dobriyan | e4dc1b1 | 2007-10-16 23:26:03 -0700 | [diff] [blame] | 1261 | list_for_each_entry(fmt, &formats, lh) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1262 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
| 1263 | if (!fn) |
| 1264 | continue; |
| 1265 | if (!try_module_get(fmt->module)) |
| 1266 | continue; |
| 1267 | read_unlock(&binfmt_lock); |
| 1268 | retval = fn(bprm, regs); |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1269 | /* |
| 1270 | * Restore the depth counter to its starting value |
| 1271 | * in this call, so we don't have to rely on every |
| 1272 | * load_binary function to restore it on return. |
| 1273 | */ |
| 1274 | bprm->recursion_depth = depth; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | if (retval >= 0) { |
Roland McGrath | 85f3346 | 2008-12-09 19:36:38 -0800 | [diff] [blame] | 1276 | if (depth == 0) |
| 1277 | tracehook_report_exec(fmt, bprm, regs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | put_binfmt(fmt); |
| 1279 | allow_write_access(bprm->file); |
| 1280 | if (bprm->file) |
| 1281 | fput(bprm->file); |
| 1282 | bprm->file = NULL; |
| 1283 | current->did_exec = 1; |
Matt Helsley | 9f46080 | 2005-11-07 00:59:16 -0800 | [diff] [blame] | 1284 | proc_exec_connector(current); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1285 | return retval; |
| 1286 | } |
| 1287 | read_lock(&binfmt_lock); |
| 1288 | put_binfmt(fmt); |
| 1289 | if (retval != -ENOEXEC || bprm->mm == NULL) |
| 1290 | break; |
| 1291 | if (!bprm->file) { |
| 1292 | read_unlock(&binfmt_lock); |
| 1293 | return retval; |
| 1294 | } |
| 1295 | } |
| 1296 | read_unlock(&binfmt_lock); |
| 1297 | if (retval != -ENOEXEC || bprm->mm == NULL) { |
| 1298 | break; |
Johannes Berg | 5f4123b | 2008-07-09 10:28:40 +0200 | [diff] [blame] | 1299 | #ifdef CONFIG_MODULES |
| 1300 | } else { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1301 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
| 1302 | if (printable(bprm->buf[0]) && |
| 1303 | printable(bprm->buf[1]) && |
| 1304 | printable(bprm->buf[2]) && |
| 1305 | printable(bprm->buf[3])) |
| 1306 | break; /* -ENOEXEC */ |
| 1307 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); |
| 1308 | #endif |
| 1309 | } |
| 1310 | } |
| 1311 | return retval; |
| 1312 | } |
| 1313 | |
| 1314 | EXPORT_SYMBOL(search_binary_handler); |
| 1315 | |
| 1316 | /* |
| 1317 | * sys_execve() executes a new program. |
| 1318 | */ |
| 1319 | int do_execve(char * filename, |
| 1320 | char __user *__user *argv, |
| 1321 | char __user *__user *envp, |
| 1322 | struct pt_regs * regs) |
| 1323 | { |
| 1324 | struct linux_binprm *bprm; |
| 1325 | struct file *file; |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1326 | struct files_struct *displaced; |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1327 | bool clear_in_exec; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1328 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1330 | retval = unshare_files(&displaced); |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1331 | if (retval) |
| 1332 | goto out_ret; |
| 1333 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | retval = -ENOMEM; |
Oliver Neukum | 11b0b5a | 2006-03-25 03:08:13 -0800 | [diff] [blame] | 1335 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1336 | if (!bprm) |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1337 | goto out_files; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1338 | |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1339 | retval = prepare_bprm_creds(bprm); |
| 1340 | if (retval) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1341 | goto out_free; |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1342 | |
| 1343 | retval = check_unsafe_exec(bprm); |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1344 | if (retval < 0) |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1345 | goto out_free; |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1346 | clear_in_exec = retval; |
Oleg Nesterov | a2a8474 | 2009-09-05 11:17:13 -0700 | [diff] [blame] | 1347 | current->in_execve = 1; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1348 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | file = open_exec(filename); |
| 1350 | retval = PTR_ERR(file); |
| 1351 | if (IS_ERR(file)) |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1352 | goto out_unmark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1353 | |
| 1354 | sched_exec(); |
| 1355 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | bprm->file = file; |
| 1357 | bprm->filename = filename; |
| 1358 | bprm->interp = filename; |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1359 | |
| 1360 | retval = bprm_mm_init(bprm); |
| 1361 | if (retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1362 | goto out_file; |
| 1363 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1364 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1365 | if ((retval = bprm->argc) < 0) |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1366 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1368 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1369 | if ((retval = bprm->envc) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1370 | goto out; |
| 1371 | |
| 1372 | retval = prepare_binprm(bprm); |
| 1373 | if (retval < 0) |
| 1374 | goto out; |
| 1375 | |
| 1376 | retval = copy_strings_kernel(1, &bprm->filename, bprm); |
| 1377 | if (retval < 0) |
| 1378 | goto out; |
| 1379 | |
| 1380 | bprm->exec = bprm->p; |
| 1381 | retval = copy_strings(bprm->envc, envp, bprm); |
| 1382 | if (retval < 0) |
| 1383 | goto out; |
| 1384 | |
| 1385 | retval = copy_strings(bprm->argc, argv, bprm); |
| 1386 | if (retval < 0) |
| 1387 | goto out; |
| 1388 | |
Oleg Nesterov | 7b34e42 | 2008-07-25 01:47:37 -0700 | [diff] [blame] | 1389 | current->flags &= ~PF_KTHREAD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1390 | retval = search_binary_handler(bprm,regs); |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1391 | if (retval < 0) |
| 1392 | goto out; |
| 1393 | |
| 1394 | /* execve succeeded */ |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1395 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1396 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1397 | acct_update_integrals(current); |
| 1398 | free_bprm(bprm); |
| 1399 | if (displaced) |
| 1400 | put_files_struct(displaced); |
| 1401 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1402 | |
| 1403 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1404 | if (bprm->mm) |
Ollie Wild | b6a2fea | 2007-07-19 01:48:16 -0700 | [diff] [blame] | 1405 | mmput (bprm->mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1406 | |
| 1407 | out_file: |
| 1408 | if (bprm->file) { |
| 1409 | allow_write_access(bprm->file); |
| 1410 | fput(bprm->file); |
| 1411 | } |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1412 | |
Al Viro | 498052b | 2009-03-30 07:20:30 -0400 | [diff] [blame] | 1413 | out_unmark: |
Oleg Nesterov | 8c652f9 | 2009-04-24 01:01:56 +0200 | [diff] [blame] | 1414 | if (clear_in_exec) |
| 1415 | current->fs->in_exec = 0; |
Kentaro Takeda | f9ce1f1 | 2009-02-05 17:18:11 +0900 | [diff] [blame] | 1416 | current->in_execve = 0; |
David Howells | a6f76f2 | 2008-11-14 10:39:24 +1100 | [diff] [blame] | 1417 | |
| 1418 | out_free: |
Al Viro | 08a6fac | 2008-05-10 16:38:25 -0400 | [diff] [blame] | 1419 | free_bprm(bprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | |
Al Viro | fd8328b | 2008-04-22 05:11:59 -0400 | [diff] [blame] | 1421 | out_files: |
Al Viro | 3b12538 | 2008-04-22 05:31:30 -0400 | [diff] [blame] | 1422 | if (displaced) |
| 1423 | reset_files_struct(displaced); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1424 | out_ret: |
| 1425 | return retval; |
| 1426 | } |
| 1427 | |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1428 | void set_binfmt(struct linux_binfmt *new) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1429 | { |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1430 | struct mm_struct *mm = current->mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1431 | |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1432 | if (mm->binfmt) |
| 1433 | module_put(mm->binfmt->module); |
| 1434 | |
| 1435 | mm->binfmt = new; |
Oleg Nesterov | 964ee7d | 2009-09-23 15:56:59 -0700 | [diff] [blame] | 1436 | if (new) |
| 1437 | __module_get(new->module); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1438 | } |
| 1439 | |
| 1440 | EXPORT_SYMBOL(set_binfmt); |
| 1441 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1442 | /* format_corename will inspect the pattern parameter, and output a |
| 1443 | * name into corename, which must have space for at least |
| 1444 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. |
| 1445 | */ |
Oleg Nesterov | 6409324 | 2008-10-18 20:28:22 -0700 | [diff] [blame] | 1446 | static int format_corename(char *corename, long signr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1447 | { |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 1448 | const struct cred *cred = current_cred(); |
Oleg Nesterov | 565b9b1 | 2008-07-25 01:47:47 -0700 | [diff] [blame] | 1449 | const char *pat_ptr = core_pattern; |
| 1450 | int ispipe = (*pat_ptr == '|'); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1451 | char *out_ptr = corename; |
| 1452 | char *const out_end = corename + CORENAME_MAX_SIZE; |
| 1453 | int rc; |
| 1454 | int pid_in_pattern = 0; |
| 1455 | |
| 1456 | /* Repeat as long as we have more pattern to process and more output |
| 1457 | space */ |
| 1458 | while (*pat_ptr) { |
| 1459 | if (*pat_ptr != '%') { |
| 1460 | if (out_ptr == out_end) |
| 1461 | goto out; |
| 1462 | *out_ptr++ = *pat_ptr++; |
| 1463 | } else { |
| 1464 | switch (*++pat_ptr) { |
| 1465 | case 0: |
| 1466 | goto out; |
| 1467 | /* Double percent, output one percent */ |
| 1468 | case '%': |
| 1469 | if (out_ptr == out_end) |
| 1470 | goto out; |
| 1471 | *out_ptr++ = '%'; |
| 1472 | break; |
| 1473 | /* pid */ |
| 1474 | case 'p': |
| 1475 | pid_in_pattern = 1; |
| 1476 | rc = snprintf(out_ptr, out_end - out_ptr, |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1477 | "%d", task_tgid_vnr(current)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1478 | if (rc > out_end - out_ptr) |
| 1479 | goto out; |
| 1480 | out_ptr += rc; |
| 1481 | break; |
| 1482 | /* uid */ |
| 1483 | case 'u': |
| 1484 | rc = snprintf(out_ptr, out_end - out_ptr, |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 1485 | "%d", cred->uid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1486 | if (rc > out_end - out_ptr) |
| 1487 | goto out; |
| 1488 | out_ptr += rc; |
| 1489 | break; |
| 1490 | /* gid */ |
| 1491 | case 'g': |
| 1492 | rc = snprintf(out_ptr, out_end - out_ptr, |
David Howells | 86a264a | 2008-11-14 10:39:18 +1100 | [diff] [blame] | 1493 | "%d", cred->gid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1494 | if (rc > out_end - out_ptr) |
| 1495 | goto out; |
| 1496 | out_ptr += rc; |
| 1497 | break; |
| 1498 | /* signal that caused the coredump */ |
| 1499 | case 's': |
| 1500 | rc = snprintf(out_ptr, out_end - out_ptr, |
| 1501 | "%ld", signr); |
| 1502 | if (rc > out_end - out_ptr) |
| 1503 | goto out; |
| 1504 | out_ptr += rc; |
| 1505 | break; |
| 1506 | /* UNIX time of coredump */ |
| 1507 | case 't': { |
| 1508 | struct timeval tv; |
| 1509 | do_gettimeofday(&tv); |
| 1510 | rc = snprintf(out_ptr, out_end - out_ptr, |
| 1511 | "%lu", tv.tv_sec); |
| 1512 | if (rc > out_end - out_ptr) |
| 1513 | goto out; |
| 1514 | out_ptr += rc; |
| 1515 | break; |
| 1516 | } |
| 1517 | /* hostname */ |
| 1518 | case 'h': |
| 1519 | down_read(&uts_sem); |
| 1520 | rc = snprintf(out_ptr, out_end - out_ptr, |
Serge E. Hallyn | e9ff399 | 2006-10-02 02:18:11 -0700 | [diff] [blame] | 1521 | "%s", utsname()->nodename); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1522 | up_read(&uts_sem); |
| 1523 | if (rc > out_end - out_ptr) |
| 1524 | goto out; |
| 1525 | out_ptr += rc; |
| 1526 | break; |
| 1527 | /* executable */ |
| 1528 | case 'e': |
| 1529 | rc = snprintf(out_ptr, out_end - out_ptr, |
| 1530 | "%s", current->comm); |
| 1531 | if (rc > out_end - out_ptr) |
| 1532 | goto out; |
| 1533 | out_ptr += rc; |
| 1534 | break; |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 1535 | /* core limit size */ |
| 1536 | case 'c': |
| 1537 | rc = snprintf(out_ptr, out_end - out_ptr, |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 1538 | "%lu", rlimit(RLIMIT_CORE)); |
Neil Horman | 74aadce | 2007-10-16 23:26:35 -0700 | [diff] [blame] | 1539 | if (rc > out_end - out_ptr) |
| 1540 | goto out; |
| 1541 | out_ptr += rc; |
| 1542 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1543 | default: |
| 1544 | break; |
| 1545 | } |
| 1546 | ++pat_ptr; |
| 1547 | } |
| 1548 | } |
| 1549 | /* Backward compatibility with core_uses_pid: |
| 1550 | * |
| 1551 | * If core_pattern does not include a %p (as is the default) |
| 1552 | * and core_uses_pid is set, then .%pid will be appended to |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1553 | * the filename. Do not do this for piped commands. */ |
Oleg Nesterov | 6409324 | 2008-10-18 20:28:22 -0700 | [diff] [blame] | 1554 | if (!ispipe && !pid_in_pattern && core_uses_pid) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1555 | rc = snprintf(out_ptr, out_end - out_ptr, |
Pavel Emelyanov | b488893 | 2007-10-18 23:40:14 -0700 | [diff] [blame] | 1556 | ".%d", task_tgid_vnr(current)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1557 | if (rc > out_end - out_ptr) |
| 1558 | goto out; |
| 1559 | out_ptr += rc; |
| 1560 | } |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1561 | out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1562 | *out_ptr = 0; |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1563 | return ispipe; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1564 | } |
| 1565 | |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1566 | static int zap_process(struct task_struct *start, int exit_code) |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1567 | { |
| 1568 | struct task_struct *t; |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1569 | int nr = 0; |
Oleg Nesterov | 281de33 | 2006-06-26 00:26:06 -0700 | [diff] [blame] | 1570 | |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1571 | start->signal->flags = SIGNAL_GROUP_EXIT; |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1572 | start->signal->group_exit_code = exit_code; |
Oleg Nesterov | d5f70c0 | 2006-06-26 00:26:07 -0700 | [diff] [blame] | 1573 | start->signal->group_stop_count = 0; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1574 | |
| 1575 | t = start; |
| 1576 | do { |
| 1577 | if (t != current && t->mm) { |
Oleg Nesterov | 281de33 | 2006-06-26 00:26:06 -0700 | [diff] [blame] | 1578 | sigaddset(&t->pending.signal, SIGKILL); |
| 1579 | signal_wake_up(t, 1); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1580 | nr++; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1581 | } |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1582 | } while_each_thread(start, t); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1583 | |
| 1584 | return nr; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1585 | } |
| 1586 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1587 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1588 | struct core_state *core_state, int exit_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1589 | { |
| 1590 | struct task_struct *g, *p; |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1591 | unsigned long flags; |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1592 | int nr = -EAGAIN; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1593 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1594 | spin_lock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | ed5d2ca | 2008-02-04 22:27:24 -0800 | [diff] [blame] | 1595 | if (!signal_group_exit(tsk->signal)) { |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1596 | mm->core_state = core_state; |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1597 | nr = zap_process(tsk, exit_code); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1598 | } |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1599 | spin_unlock_irq(&tsk->sighand->siglock); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1600 | if (unlikely(nr < 0)) |
| 1601 | return nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1602 | |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1603 | if (atomic_read(&mm->mm_users) == nr + 1) |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1604 | goto done; |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1605 | /* |
| 1606 | * We should find and kill all tasks which use this mm, and we should |
Oleg Nesterov | 999d9fc | 2008-07-25 01:47:41 -0700 | [diff] [blame] | 1607 | * count them correctly into ->nr_threads. We don't take tasklist |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1608 | * lock, but this is safe wrt: |
| 1609 | * |
| 1610 | * fork: |
| 1611 | * None of sub-threads can fork after zap_process(leader). All |
| 1612 | * processes which were created before this point should be |
| 1613 | * visible to zap_threads() because copy_process() adds the new |
| 1614 | * process to the tail of init_task.tasks list, and lock/unlock |
| 1615 | * of ->siglock provides a memory barrier. |
| 1616 | * |
| 1617 | * do_exit: |
| 1618 | * The caller holds mm->mmap_sem. This means that the task which |
| 1619 | * uses this mm can't pass exit_mm(), so it can't exit or clear |
| 1620 | * its ->mm. |
| 1621 | * |
| 1622 | * de_thread: |
| 1623 | * It does list_replace_rcu(&leader->tasks, ¤t->tasks), |
| 1624 | * we must see either old or new leader, this does not matter. |
| 1625 | * However, it can change p->sighand, so lock_task_sighand(p) |
| 1626 | * must be used. Since p->mm != NULL and we hold ->mmap_sem |
| 1627 | * it can't fail. |
| 1628 | * |
| 1629 | * Note also that "g" can be the old leader with ->mm == NULL |
| 1630 | * and already unhashed and thus removed from ->thread_group. |
| 1631 | * This is OK, __unhash_process()->list_del_rcu() does not |
| 1632 | * clear the ->next pointer, we will find the new leader via |
| 1633 | * next_thread(). |
| 1634 | */ |
Oleg Nesterov | 7b1c615 | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1635 | rcu_read_lock(); |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1636 | for_each_process(g) { |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1637 | if (g == tsk->group_leader) |
| 1638 | continue; |
Oleg Nesterov | 15b9f36 | 2008-07-25 01:47:39 -0700 | [diff] [blame] | 1639 | if (g->flags & PF_KTHREAD) |
| 1640 | continue; |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1641 | p = g; |
| 1642 | do { |
| 1643 | if (p->mm) { |
Oleg Nesterov | 15b9f36 | 2008-07-25 01:47:39 -0700 | [diff] [blame] | 1644 | if (unlikely(p->mm == mm)) { |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1645 | lock_task_sighand(p, &flags); |
Oleg Nesterov | 5c99cbf | 2010-03-05 13:44:14 -0800 | [diff] [blame] | 1646 | nr += zap_process(p, exit_code); |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1647 | unlock_task_sighand(p, &flags); |
| 1648 | } |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1649 | break; |
| 1650 | } |
Oleg Nesterov | e4901f9 | 2008-07-25 01:47:31 -0700 | [diff] [blame] | 1651 | } while_each_thread(g, p); |
Oleg Nesterov | aceecc04 | 2006-06-26 00:26:05 -0700 | [diff] [blame] | 1652 | } |
Oleg Nesterov | 7b1c615 | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1653 | rcu_read_unlock(); |
Oleg Nesterov | 5debfa6 | 2006-06-26 00:26:09 -0700 | [diff] [blame] | 1654 | done: |
Oleg Nesterov | c5f1cc8 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1655 | atomic_set(&core_state->nr_threads, nr); |
Oleg Nesterov | 8cd9c24 | 2008-07-25 01:47:42 -0700 | [diff] [blame] | 1656 | return nr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | } |
| 1658 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1659 | static int coredump_wait(int exit_code, struct core_state *core_state) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1660 | { |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1661 | struct task_struct *tsk = current; |
| 1662 | struct mm_struct *mm = tsk->mm; |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1663 | struct completion *vfork_done; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 1664 | int core_waiters = -EBUSY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1665 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1666 | init_completion(&core_state->startup); |
Oleg Nesterov | b564daf | 2008-07-25 01:47:44 -0700 | [diff] [blame] | 1667 | core_state->dumper.task = tsk; |
| 1668 | core_state->dumper.next = NULL; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 1669 | |
| 1670 | down_write(&mm->mmap_sem); |
| 1671 | if (!mm->core_state) |
| 1672 | core_waiters = zap_threads(tsk, mm, core_state, exit_code); |
Oleg Nesterov | 2384f55 | 2005-10-30 15:02:47 -0800 | [diff] [blame] | 1673 | up_write(&mm->mmap_sem); |
| 1674 | |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1675 | if (unlikely(core_waiters < 0)) |
| 1676 | goto fail; |
| 1677 | |
| 1678 | /* |
| 1679 | * Make sure nobody is waiting for us to release the VM, |
| 1680 | * otherwise we can deadlock when we wait on each other |
| 1681 | */ |
| 1682 | vfork_done = tsk->vfork_done; |
| 1683 | if (vfork_done) { |
| 1684 | tsk->vfork_done = NULL; |
| 1685 | complete(vfork_done); |
| 1686 | } |
| 1687 | |
Oleg Nesterov | 2384f55 | 2005-10-30 15:02:47 -0800 | [diff] [blame] | 1688 | if (core_waiters) |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1689 | wait_for_completion(&core_state->startup); |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1690 | fail: |
Oleg Nesterov | dcf560c | 2006-06-26 00:26:08 -0700 | [diff] [blame] | 1691 | return core_waiters; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1692 | } |
| 1693 | |
Oleg Nesterov | a94e2d4 | 2008-07-25 01:47:46 -0700 | [diff] [blame] | 1694 | static void coredump_finish(struct mm_struct *mm) |
| 1695 | { |
| 1696 | struct core_thread *curr, *next; |
| 1697 | struct task_struct *task; |
| 1698 | |
| 1699 | next = mm->core_state->dumper.next; |
| 1700 | while ((curr = next) != NULL) { |
| 1701 | next = curr->next; |
| 1702 | task = curr->task; |
| 1703 | /* |
| 1704 | * see exit_mm(), curr->task must not see |
| 1705 | * ->task == NULL before we read ->next. |
| 1706 | */ |
| 1707 | smp_mb(); |
| 1708 | curr->task = NULL; |
| 1709 | wake_up_process(task); |
| 1710 | } |
| 1711 | |
| 1712 | mm->core_state = NULL; |
| 1713 | } |
| 1714 | |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1715 | /* |
| 1716 | * set_dumpable converts traditional three-value dumpable to two flags and |
| 1717 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but |
| 1718 | * these bits are not changed atomically. So get_dumpable can observe the |
| 1719 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable |
| 1720 | * return either old dumpable or new one by paying attention to the order of |
| 1721 | * modifying the bits. |
| 1722 | * |
| 1723 | * dumpable | mm->flags (binary) |
| 1724 | * old new | initial interim final |
| 1725 | * ---------+----------------------- |
| 1726 | * 0 1 | 00 01 01 |
| 1727 | * 0 2 | 00 10(*) 11 |
| 1728 | * 1 0 | 01 00 00 |
| 1729 | * 1 2 | 01 11 11 |
| 1730 | * 2 0 | 11 10(*) 00 |
| 1731 | * 2 1 | 11 11 01 |
| 1732 | * |
| 1733 | * (*) get_dumpable regards interim value of 10 as 11. |
| 1734 | */ |
| 1735 | void set_dumpable(struct mm_struct *mm, int value) |
| 1736 | { |
| 1737 | switch (value) { |
| 1738 | case 0: |
| 1739 | clear_bit(MMF_DUMPABLE, &mm->flags); |
| 1740 | smp_wmb(); |
| 1741 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 1742 | break; |
| 1743 | case 1: |
| 1744 | set_bit(MMF_DUMPABLE, &mm->flags); |
| 1745 | smp_wmb(); |
| 1746 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 1747 | break; |
| 1748 | case 2: |
| 1749 | set_bit(MMF_DUMP_SECURELY, &mm->flags); |
| 1750 | smp_wmb(); |
| 1751 | set_bit(MMF_DUMPABLE, &mm->flags); |
| 1752 | break; |
| 1753 | } |
| 1754 | } |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1755 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1756 | static int __get_dumpable(unsigned long mm_flags) |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1757 | { |
| 1758 | int ret; |
| 1759 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1760 | ret = mm_flags & MMF_DUMPABLE_MASK; |
Kawai, Hidehiro | 6c5d523 | 2007-07-19 01:48:27 -0700 | [diff] [blame] | 1761 | return (ret >= 2) ? 2 : ret; |
| 1762 | } |
| 1763 | |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1764 | int get_dumpable(struct mm_struct *mm) |
| 1765 | { |
| 1766 | return __get_dumpable(mm->flags); |
| 1767 | } |
| 1768 | |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 1769 | static void wait_for_dump_helpers(struct file *file) |
| 1770 | { |
| 1771 | struct pipe_inode_info *pipe; |
| 1772 | |
| 1773 | pipe = file->f_path.dentry->d_inode->i_pipe; |
| 1774 | |
| 1775 | pipe_lock(pipe); |
| 1776 | pipe->readers++; |
| 1777 | pipe->writers--; |
| 1778 | |
| 1779 | while ((pipe->readers > 1) && (!signal_pending(current))) { |
| 1780 | wake_up_interruptible_sync(&pipe->wait); |
| 1781 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
| 1782 | pipe_wait(pipe); |
| 1783 | } |
| 1784 | |
| 1785 | pipe->readers--; |
| 1786 | pipe->writers++; |
| 1787 | pipe_unlock(pipe); |
| 1788 | |
| 1789 | } |
| 1790 | |
| 1791 | |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 1792 | /* |
| 1793 | * uhm_pipe_setup |
| 1794 | * helper function to customize the process used |
| 1795 | * to collect the core in userspace. Specifically |
| 1796 | * it sets up a pipe and installs it as fd 0 (stdin) |
| 1797 | * for the process. Returns 0 on success, or |
| 1798 | * PTR_ERR on failure. |
| 1799 | * Note that it also sets the core limit to 1. This |
| 1800 | * is a special value that we use to trap recursive |
| 1801 | * core dumps |
| 1802 | */ |
| 1803 | static int umh_pipe_setup(struct subprocess_info *info) |
| 1804 | { |
| 1805 | struct file *rp, *wp; |
| 1806 | struct fdtable *fdt; |
| 1807 | struct coredump_params *cp = (struct coredump_params *)info->data; |
| 1808 | struct files_struct *cf = current->files; |
| 1809 | |
| 1810 | wp = create_write_pipe(0); |
| 1811 | if (IS_ERR(wp)) |
| 1812 | return PTR_ERR(wp); |
| 1813 | |
| 1814 | rp = create_read_pipe(wp, 0); |
| 1815 | if (IS_ERR(rp)) { |
| 1816 | free_write_pipe(wp); |
| 1817 | return PTR_ERR(rp); |
| 1818 | } |
| 1819 | |
| 1820 | cp->file = wp; |
| 1821 | |
| 1822 | sys_close(0); |
| 1823 | fd_install(0, rp); |
| 1824 | spin_lock(&cf->file_lock); |
| 1825 | fdt = files_fdtable(cf); |
| 1826 | FD_SET(0, fdt->open_fds); |
| 1827 | FD_CLR(0, fdt->close_on_exec); |
| 1828 | spin_unlock(&cf->file_lock); |
| 1829 | |
| 1830 | /* and disallow core files too */ |
| 1831 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; |
| 1832 | |
| 1833 | return 0; |
| 1834 | } |
| 1835 | |
WANG Cong | 8cd3ac3 | 2009-01-06 14:42:48 -0800 | [diff] [blame] | 1836 | void do_coredump(long signr, int exit_code, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1837 | { |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1838 | struct core_state core_state; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1839 | char corename[CORENAME_MAX_SIZE + 1]; |
| 1840 | struct mm_struct *mm = current->mm; |
| 1841 | struct linux_binfmt * binfmt; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1842 | const struct cred *old_cred; |
| 1843 | struct cred *cred; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1844 | int retval = 0; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1845 | int flag = 0; |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1846 | int ispipe; |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 1847 | static atomic_t core_dump_count = ATOMIC_INIT(0); |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 1848 | struct coredump_params cprm = { |
| 1849 | .signr = signr, |
| 1850 | .regs = regs, |
Jiri Slaby | d554ed89 | 2010-03-05 13:42:42 -0800 | [diff] [blame] | 1851 | .limit = rlimit(RLIMIT_CORE), |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1852 | /* |
| 1853 | * We must use the same mm->flags while dumping core to avoid |
| 1854 | * inconsistency of bit flags, since this flag is not protected |
| 1855 | * by any locks. |
| 1856 | */ |
| 1857 | .mm_flags = mm->flags, |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 1858 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1859 | |
Steve Grubb | 0a4ff8c | 2007-04-19 10:28:21 -0400 | [diff] [blame] | 1860 | audit_core_dumps(signr); |
| 1861 | |
Hiroshi Shimamoto | 801460d | 2009-09-23 15:57:41 -0700 | [diff] [blame] | 1862 | binfmt = mm->binfmt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1863 | if (!binfmt || !binfmt->core_dump) |
| 1864 | goto fail; |
Oleg Nesterov | 269b005 | 2010-05-26 14:43:08 -0700 | [diff] [blame] | 1865 | if (!__get_dumpable(cprm.mm_flags)) |
| 1866 | goto fail; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1867 | |
| 1868 | cred = prepare_creds(); |
Oleg Nesterov | 5e43aef5 | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 1869 | if (!cred) |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1870 | goto fail; |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1871 | /* |
| 1872 | * We cannot trust fsuid as being the "true" uid of the |
| 1873 | * process nor do we know its entire history. We only know it |
| 1874 | * was tainted so we dump it as root in mode 2. |
| 1875 | */ |
Masami Hiramatsu | 30736a4 | 2010-03-05 13:44:12 -0800 | [diff] [blame] | 1876 | if (__get_dumpable(cprm.mm_flags) == 2) { |
| 1877 | /* Setuid core dump mode */ |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1878 | flag = O_EXCL; /* Stop rewrite attacks */ |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1879 | cred->fsuid = 0; /* Dump root private */ |
Alan Cox | d6e7114 | 2005-06-23 00:09:43 -0700 | [diff] [blame] | 1880 | } |
Oleg Nesterov | 1291cf4 | 2005-10-30 15:02:54 -0800 | [diff] [blame] | 1881 | |
Oleg Nesterov | 9d5b327 | 2008-07-25 01:47:43 -0700 | [diff] [blame] | 1882 | retval = coredump_wait(exit_code, &core_state); |
Oleg Nesterov | 5e43aef5 | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 1883 | if (retval < 0) |
| 1884 | goto fail_creds; |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 1885 | |
| 1886 | old_cred = override_creds(cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1887 | |
| 1888 | /* |
| 1889 | * Clear any false indication of pending signals that might |
| 1890 | * be seen by the filesystem code called to write the core file. |
| 1891 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1892 | clear_thread_flag(TIF_SIGPENDING); |
| 1893 | |
Oleg Nesterov | 6409324 | 2008-10-18 20:28:22 -0700 | [diff] [blame] | 1894 | ispipe = format_corename(corename, signr); |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 1895 | |
Alan Cox | c4bbafd | 2007-04-16 22:53:13 -0700 | [diff] [blame] | 1896 | if (ispipe) { |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1897 | int dump_count; |
| 1898 | char **helper_argv; |
| 1899 | |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 1900 | if (cprm.limit == 1) { |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 1901 | /* |
| 1902 | * Normally core limits are irrelevant to pipes, since |
| 1903 | * we're not writing to the file system, but we use |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 1904 | * cprm.limit of 1 here as a speacial value. Any |
| 1905 | * non-1 limit gets set to RLIM_INFINITY below, but |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 1906 | * a limit of 0 skips the dump. This is a consistent |
| 1907 | * way to catch recursive crashes. We can still crash |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 1908 | * if the core_pattern binary sets RLIM_CORE = !1 |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 1909 | * but it runs as root, and can do lots of stupid things |
| 1910 | * Note that we use task_tgid_vnr here to grab the pid |
| 1911 | * of the process group leader. That way we get the |
| 1912 | * right pid if a thread in a multi-threaded |
| 1913 | * core_pattern process dies. |
| 1914 | */ |
| 1915 | printk(KERN_WARNING |
Neil Horman | 898b374 | 2010-05-26 14:42:59 -0700 | [diff] [blame] | 1916 | "Process %d(%s) has RLIMIT_CORE set to 1\n", |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 1917 | task_tgid_vnr(current), current->comm); |
| 1918 | printk(KERN_WARNING "Aborting core\n"); |
| 1919 | goto fail_unlock; |
| 1920 | } |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1921 | cprm.limit = RLIM_INFINITY; |
Neil Horman | 725eae3 | 2009-09-23 15:56:54 -0700 | [diff] [blame] | 1922 | |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 1923 | dump_count = atomic_inc_return(&core_dump_count); |
| 1924 | if (core_pipe_limit && (core_pipe_limit < dump_count)) { |
| 1925 | printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", |
| 1926 | task_tgid_vnr(current), current->comm); |
| 1927 | printk(KERN_WARNING "Skipping core dump\n"); |
| 1928 | goto fail_dropcount; |
| 1929 | } |
| 1930 | |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1931 | helper_argv = argv_split(GFP_KERNEL, corename+1, NULL); |
Tetsuo Handa | 350eaf7 | 2009-01-06 14:41:11 -0800 | [diff] [blame] | 1932 | if (!helper_argv) { |
| 1933 | printk(KERN_WARNING "%s failed to allocate memory\n", |
| 1934 | __func__); |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 1935 | goto fail_dropcount; |
Tetsuo Handa | 350eaf7 | 2009-01-06 14:41:11 -0800 | [diff] [blame] | 1936 | } |
Neil Horman | 3232113 | 2007-10-16 23:26:36 -0700 | [diff] [blame] | 1937 | |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1938 | retval = call_usermodehelper_fns(helper_argv[0], helper_argv, |
| 1939 | NULL, UMH_WAIT_EXEC, umh_pipe_setup, |
| 1940 | NULL, &cprm); |
| 1941 | argv_free(helper_argv); |
| 1942 | if (retval) { |
Andi Kleen | d025c9d | 2006-09-30 23:29:28 -0700 | [diff] [blame] | 1943 | printk(KERN_INFO "Core dump to %s pipe failed\n", |
| 1944 | corename); |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1945 | goto close_fail; |
Andi Kleen | d025c9d | 2006-09-30 23:29:28 -0700 | [diff] [blame] | 1946 | } |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 1947 | } else { |
| 1948 | struct inode *inode; |
| 1949 | |
| 1950 | if (cprm.limit < binfmt->min_coredump) |
| 1951 | goto fail_unlock; |
| 1952 | |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 1953 | cprm.file = filp_open(corename, |
Alexey Dobriyan | 6d4df67 | 2006-12-06 20:40:39 -0800 | [diff] [blame] | 1954 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
| 1955 | 0600); |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 1956 | if (IS_ERR(cprm.file)) |
| 1957 | goto fail_unlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1958 | |
Oleg Nesterov | c713541 | 2010-05-26 14:43:05 -0700 | [diff] [blame] | 1959 | inode = cprm.file->f_path.dentry->d_inode; |
| 1960 | if (inode->i_nlink > 1) |
| 1961 | goto close_fail; |
| 1962 | if (d_unhashed(cprm.file->f_path.dentry)) |
| 1963 | goto close_fail; |
| 1964 | /* |
| 1965 | * AK: actually i see no reason to not allow this for named |
| 1966 | * pipes etc, but keep the previous behaviour for now. |
| 1967 | */ |
| 1968 | if (!S_ISREG(inode->i_mode)) |
| 1969 | goto close_fail; |
| 1970 | /* |
| 1971 | * Dont allow local users get cute and trick others to coredump |
| 1972 | * into their pre-created files. |
| 1973 | */ |
| 1974 | if (inode->i_uid != current_fsuid()) |
| 1975 | goto close_fail; |
| 1976 | if (!cprm.file->f_op || !cprm.file->f_op->write) |
| 1977 | goto close_fail; |
| 1978 | if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file)) |
| 1979 | goto close_fail; |
| 1980 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1981 | |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 1982 | retval = binfmt->core_dump(&cprm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1983 | if (retval) |
| 1984 | current->signal->group_exit_code |= 0x80; |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1985 | |
Neil Horman | 61be228 | 2009-09-23 15:56:58 -0700 | [diff] [blame] | 1986 | if (ispipe && core_pipe_limit) |
Masami Hiramatsu | f6151df | 2009-12-17 15:27:16 -0800 | [diff] [blame] | 1987 | wait_for_dump_helpers(cprm.file); |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1988 | close_fail: |
| 1989 | if (cprm.file) |
| 1990 | filp_close(cprm.file, NULL); |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 1991 | fail_dropcount: |
Oleg Nesterov | d5bf4c4 | 2010-05-26 14:43:06 -0700 | [diff] [blame] | 1992 | if (ispipe) |
Neil Horman | a293980 | 2009-09-23 15:56:56 -0700 | [diff] [blame] | 1993 | atomic_dec(&core_dump_count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1994 | fail_unlock: |
Oleg Nesterov | a94e2d4 | 2008-07-25 01:47:46 -0700 | [diff] [blame] | 1995 | coredump_finish(mm); |
Oleg Nesterov | 5e43aef5 | 2010-05-26 14:43:07 -0700 | [diff] [blame] | 1996 | revert_creds(old_cred); |
| 1997 | fail_creds: |
| 1998 | put_cred(cred); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1999 | fail: |
WANG Cong | 8cd3ac3 | 2009-01-06 14:42:48 -0800 | [diff] [blame] | 2000 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2001 | } |