Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
1da177e4 LT |
25 | #include <linux/slab.h> |
26 | #include <linux/file.h> | |
9f3acc31 | 27 | #include <linux/fdtable.h> |
ba92a43d | 28 | #include <linux/mm.h> |
1da177e4 LT |
29 | #include <linux/stat.h> |
30 | #include <linux/fcntl.h> | |
ba92a43d | 31 | #include <linux/swap.h> |
74aadce9 | 32 | #include <linux/string.h> |
1da177e4 | 33 | #include <linux/init.h> |
ca5b172b | 34 | #include <linux/pagemap.h> |
cdd6c482 | 35 | #include <linux/perf_event.h> |
1da177e4 LT |
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> | |
1da177e4 | 41 | #include <linux/utsname.h> |
84d73786 | 42 | #include <linux/pid_namespace.h> |
1da177e4 LT |
43 | #include <linux/module.h> |
44 | #include <linux/namei.h> | |
45 | #include <linux/proc_fs.h> | |
1da177e4 LT |
46 | #include <linux/mount.h> |
47 | #include <linux/security.h> | |
48 | #include <linux/syscalls.h> | |
8f0ab514 | 49 | #include <linux/tsacct_kern.h> |
9f46080c | 50 | #include <linux/cn_proc.h> |
473ae30b | 51 | #include <linux/audit.h> |
6341c393 | 52 | #include <linux/tracehook.h> |
5f4123be | 53 | #include <linux/kmod.h> |
6110e3ab | 54 | #include <linux/fsnotify.h> |
5ad4e53b | 55 | #include <linux/fs_struct.h> |
61be228a | 56 | #include <linux/pipe_fs_i.h> |
3d5992d2 | 57 | #include <linux/oom.h> |
0e028465 | 58 | #include <linux/compat.h> |
1da177e4 LT |
59 | |
60 | #include <asm/uaccess.h> | |
61 | #include <asm/mmu_context.h> | |
b6a2fea3 | 62 | #include <asm/tlb.h> |
a6f76f23 | 63 | #include "internal.h" |
1da177e4 | 64 | |
1da177e4 | 65 | int core_uses_pid; |
71ce92f3 | 66 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
a293980c | 67 | unsigned int core_pipe_limit; |
d6e71144 AC |
68 | int suid_dumpable = 0; |
69 | ||
1b0d300b XF |
70 | struct core_name { |
71 | char *corename; | |
72 | int used, size; | |
73 | }; | |
74 | static atomic_t call_count = ATOMIC_INIT(1); | |
75 | ||
1da177e4 LT |
76 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
77 | ||
e4dc1b14 | 78 | static LIST_HEAD(formats); |
1da177e4 LT |
79 | static DEFINE_RWLOCK(binfmt_lock); |
80 | ||
74641f58 | 81 | int __register_binfmt(struct linux_binfmt * fmt, int insert) |
1da177e4 | 82 | { |
1da177e4 LT |
83 | if (!fmt) |
84 | return -EINVAL; | |
1da177e4 | 85 | write_lock(&binfmt_lock); |
74641f58 IK |
86 | insert ? list_add(&fmt->lh, &formats) : |
87 | list_add_tail(&fmt->lh, &formats); | |
1da177e4 LT |
88 | write_unlock(&binfmt_lock); |
89 | return 0; | |
90 | } | |
91 | ||
74641f58 | 92 | EXPORT_SYMBOL(__register_binfmt); |
1da177e4 | 93 | |
f6b450d4 | 94 | void unregister_binfmt(struct linux_binfmt * fmt) |
1da177e4 | 95 | { |
1da177e4 | 96 | write_lock(&binfmt_lock); |
e4dc1b14 | 97 | list_del(&fmt->lh); |
1da177e4 | 98 | write_unlock(&binfmt_lock); |
1da177e4 LT |
99 | } |
100 | ||
101 | EXPORT_SYMBOL(unregister_binfmt); | |
102 | ||
103 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
104 | { | |
105 | module_put(fmt->module); | |
106 | } | |
107 | ||
108 | /* | |
109 | * Note that a shared library must be both readable and executable due to | |
110 | * security reasons. | |
111 | * | |
112 | * Also note that we take the address to load from from the file itself. | |
113 | */ | |
1e7bfb21 | 114 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
1da177e4 | 115 | { |
964bd183 | 116 | struct file *file; |
964bd183 AV |
117 | char *tmp = getname(library); |
118 | int error = PTR_ERR(tmp); | |
47c805dc AV |
119 | static const struct open_flags uselib_flags = { |
120 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
121 | .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, | |
122 | .intent = LOOKUP_OPEN | |
123 | }; | |
964bd183 | 124 | |
6e8341a1 AV |
125 | if (IS_ERR(tmp)) |
126 | goto out; | |
127 | ||
47c805dc | 128 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); |
6e8341a1 AV |
129 | putname(tmp); |
130 | error = PTR_ERR(file); | |
131 | if (IS_ERR(file)) | |
1da177e4 LT |
132 | goto out; |
133 | ||
134 | error = -EINVAL; | |
6e8341a1 | 135 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
1da177e4 LT |
136 | goto exit; |
137 | ||
30524472 | 138 | error = -EACCES; |
6e8341a1 | 139 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
1da177e4 LT |
140 | goto exit; |
141 | ||
2a12a9d7 | 142 | fsnotify_open(file); |
6110e3ab | 143 | |
1da177e4 LT |
144 | error = -ENOEXEC; |
145 | if(file->f_op) { | |
146 | struct linux_binfmt * fmt; | |
147 | ||
148 | read_lock(&binfmt_lock); | |
e4dc1b14 | 149 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
150 | if (!fmt->load_shlib) |
151 | continue; | |
152 | if (!try_module_get(fmt->module)) | |
153 | continue; | |
154 | read_unlock(&binfmt_lock); | |
155 | error = fmt->load_shlib(file); | |
156 | read_lock(&binfmt_lock); | |
157 | put_binfmt(fmt); | |
158 | if (error != -ENOEXEC) | |
159 | break; | |
160 | } | |
161 | read_unlock(&binfmt_lock); | |
162 | } | |
6e8341a1 | 163 | exit: |
1da177e4 LT |
164 | fput(file); |
165 | out: | |
166 | return error; | |
1da177e4 LT |
167 | } |
168 | ||
b6a2fea3 | 169 | #ifdef CONFIG_MMU |
ae6b585e ON |
170 | /* |
171 | * The nascent bprm->mm is not visible until exec_mmap() but it can | |
172 | * use a lot of memory, account these pages in current->mm temporary | |
173 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we | |
174 | * change the counter back via acct_arg_size(0). | |
175 | */ | |
0e028465 | 176 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
177 | { |
178 | struct mm_struct *mm = current->mm; | |
179 | long diff = (long)(pages - bprm->vma_pages); | |
180 | ||
181 | if (!mm || !diff) | |
182 | return; | |
183 | ||
184 | bprm->vma_pages = pages; | |
185 | ||
186 | #ifdef SPLIT_RSS_COUNTING | |
187 | add_mm_counter(mm, MM_ANONPAGES, diff); | |
188 | #else | |
189 | spin_lock(&mm->page_table_lock); | |
190 | add_mm_counter(mm, MM_ANONPAGES, diff); | |
191 | spin_unlock(&mm->page_table_lock); | |
192 | #endif | |
193 | } | |
194 | ||
0e028465 | 195 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
196 | int write) |
197 | { | |
198 | struct page *page; | |
199 | int ret; | |
200 | ||
201 | #ifdef CONFIG_STACK_GROWSUP | |
202 | if (write) { | |
203 | ret = expand_stack_downwards(bprm->vma, pos); | |
204 | if (ret < 0) | |
205 | return NULL; | |
206 | } | |
207 | #endif | |
208 | ret = get_user_pages(current, bprm->mm, pos, | |
209 | 1, write, 1, &page, NULL); | |
210 | if (ret <= 0) | |
211 | return NULL; | |
212 | ||
213 | if (write) { | |
b6a2fea3 | 214 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
a64e715f LT |
215 | struct rlimit *rlim; |
216 | ||
3c77f845 ON |
217 | acct_arg_size(bprm, size / PAGE_SIZE); |
218 | ||
a64e715f LT |
219 | /* |
220 | * We've historically supported up to 32 pages (ARG_MAX) | |
221 | * of argument strings even with small stacks | |
222 | */ | |
223 | if (size <= ARG_MAX) | |
224 | return page; | |
b6a2fea3 OW |
225 | |
226 | /* | |
227 | * Limit to 1/4-th the stack size for the argv+env strings. | |
228 | * This ensures that: | |
229 | * - the remaining binfmt code will not run out of stack space, | |
230 | * - the program will have a reasonable amount of stack left | |
231 | * to work from. | |
232 | */ | |
a64e715f | 233 | rlim = current->signal->rlim; |
d554ed89 | 234 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
b6a2fea3 OW |
235 | put_page(page); |
236 | return NULL; | |
237 | } | |
238 | } | |
239 | ||
240 | return page; | |
241 | } | |
242 | ||
243 | static void put_arg_page(struct page *page) | |
244 | { | |
245 | put_page(page); | |
246 | } | |
247 | ||
248 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
249 | { | |
250 | } | |
251 | ||
252 | static void free_arg_pages(struct linux_binprm *bprm) | |
253 | { | |
254 | } | |
255 | ||
256 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
257 | struct page *page) | |
258 | { | |
259 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); | |
260 | } | |
261 | ||
262 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
263 | { | |
eaccbfa5 | 264 | int err; |
b6a2fea3 OW |
265 | struct vm_area_struct *vma = NULL; |
266 | struct mm_struct *mm = bprm->mm; | |
267 | ||
268 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
269 | if (!vma) | |
eaccbfa5 | 270 | return -ENOMEM; |
b6a2fea3 OW |
271 | |
272 | down_write(&mm->mmap_sem); | |
273 | vma->vm_mm = mm; | |
274 | ||
275 | /* | |
276 | * Place the stack at the largest stack address the architecture | |
277 | * supports. Later, we'll move this to an appropriate place. We don't | |
278 | * use STACK_TOP because that can depend on attributes which aren't | |
279 | * configured yet. | |
280 | */ | |
a8bef8ff | 281 | BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
b6a2fea3 OW |
282 | vma->vm_end = STACK_TOP_MAX; |
283 | vma->vm_start = vma->vm_end - PAGE_SIZE; | |
a8bef8ff | 284 | vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
3ed75eb8 | 285 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
5beb4930 | 286 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
462e635e TO |
287 | |
288 | err = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1); | |
289 | if (err) | |
290 | goto err; | |
291 | ||
b6a2fea3 | 292 | err = insert_vm_struct(mm, vma); |
eaccbfa5 | 293 | if (err) |
b6a2fea3 | 294 | goto err; |
b6a2fea3 OW |
295 | |
296 | mm->stack_vm = mm->total_vm = 1; | |
297 | up_write(&mm->mmap_sem); | |
b6a2fea3 | 298 | bprm->p = vma->vm_end - sizeof(void *); |
b6a2fea3 | 299 | return 0; |
b6a2fea3 | 300 | err: |
eaccbfa5 LFC |
301 | up_write(&mm->mmap_sem); |
302 | bprm->vma = NULL; | |
303 | kmem_cache_free(vm_area_cachep, vma); | |
b6a2fea3 OW |
304 | return err; |
305 | } | |
306 | ||
307 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
308 | { | |
309 | return len <= MAX_ARG_STRLEN; | |
310 | } | |
311 | ||
312 | #else | |
313 | ||
0e028465 | 314 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
315 | { |
316 | } | |
317 | ||
0e028465 | 318 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
319 | int write) |
320 | { | |
321 | struct page *page; | |
322 | ||
323 | page = bprm->page[pos / PAGE_SIZE]; | |
324 | if (!page && write) { | |
325 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); | |
326 | if (!page) | |
327 | return NULL; | |
328 | bprm->page[pos / PAGE_SIZE] = page; | |
329 | } | |
330 | ||
331 | return page; | |
332 | } | |
333 | ||
334 | static void put_arg_page(struct page *page) | |
335 | { | |
336 | } | |
337 | ||
338 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
339 | { | |
340 | if (bprm->page[i]) { | |
341 | __free_page(bprm->page[i]); | |
342 | bprm->page[i] = NULL; | |
343 | } | |
344 | } | |
345 | ||
346 | static void free_arg_pages(struct linux_binprm *bprm) | |
347 | { | |
348 | int i; | |
349 | ||
350 | for (i = 0; i < MAX_ARG_PAGES; i++) | |
351 | free_arg_page(bprm, i); | |
352 | } | |
353 | ||
354 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
355 | struct page *page) | |
356 | { | |
357 | } | |
358 | ||
359 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
360 | { | |
361 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); | |
362 | return 0; | |
363 | } | |
364 | ||
365 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
366 | { | |
367 | return len <= bprm->p; | |
368 | } | |
369 | ||
370 | #endif /* CONFIG_MMU */ | |
371 | ||
372 | /* | |
373 | * Create a new mm_struct and populate it with a temporary stack | |
374 | * vm_area_struct. We don't have enough context at this point to set the stack | |
375 | * flags, permissions, and offset, so we use temporary values. We'll update | |
376 | * them later in setup_arg_pages(). | |
377 | */ | |
378 | int bprm_mm_init(struct linux_binprm *bprm) | |
379 | { | |
380 | int err; | |
381 | struct mm_struct *mm = NULL; | |
382 | ||
383 | bprm->mm = mm = mm_alloc(); | |
384 | err = -ENOMEM; | |
385 | if (!mm) | |
386 | goto err; | |
387 | ||
388 | err = init_new_context(current, mm); | |
389 | if (err) | |
390 | goto err; | |
391 | ||
392 | err = __bprm_mm_init(bprm); | |
393 | if (err) | |
394 | goto err; | |
395 | ||
396 | return 0; | |
397 | ||
398 | err: | |
399 | if (mm) { | |
400 | bprm->mm = NULL; | |
401 | mmdrop(mm); | |
402 | } | |
403 | ||
404 | return err; | |
405 | } | |
406 | ||
ba2d0162 | 407 | struct user_arg_ptr { |
0e028465 ON |
408 | #ifdef CONFIG_COMPAT |
409 | bool is_compat; | |
410 | #endif | |
411 | union { | |
412 | const char __user *const __user *native; | |
413 | #ifdef CONFIG_COMPAT | |
414 | compat_uptr_t __user *compat; | |
415 | #endif | |
416 | } ptr; | |
ba2d0162 ON |
417 | }; |
418 | ||
419 | static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) | |
1d1dbf81 | 420 | { |
0e028465 ON |
421 | const char __user *native; |
422 | ||
423 | #ifdef CONFIG_COMPAT | |
424 | if (unlikely(argv.is_compat)) { | |
425 | compat_uptr_t compat; | |
426 | ||
427 | if (get_user(compat, argv.ptr.compat + nr)) | |
428 | return ERR_PTR(-EFAULT); | |
1d1dbf81 | 429 | |
0e028465 ON |
430 | return compat_ptr(compat); |
431 | } | |
432 | #endif | |
433 | ||
434 | if (get_user(native, argv.ptr.native + nr)) | |
1d1dbf81 ON |
435 | return ERR_PTR(-EFAULT); |
436 | ||
0e028465 | 437 | return native; |
1d1dbf81 ON |
438 | } |
439 | ||
1da177e4 LT |
440 | /* |
441 | * count() counts the number of strings in array ARGV. | |
442 | */ | |
ba2d0162 | 443 | static int count(struct user_arg_ptr argv, int max) |
1da177e4 LT |
444 | { |
445 | int i = 0; | |
446 | ||
0e028465 | 447 | if (argv.ptr.native != NULL) { |
1da177e4 | 448 | for (;;) { |
1d1dbf81 | 449 | const char __user *p = get_user_arg_ptr(argv, i); |
1da177e4 | 450 | |
1da177e4 LT |
451 | if (!p) |
452 | break; | |
1d1dbf81 ON |
453 | |
454 | if (IS_ERR(p)) | |
455 | return -EFAULT; | |
456 | ||
362e6663 | 457 | if (i++ >= max) |
1da177e4 | 458 | return -E2BIG; |
9aea5a65 RM |
459 | |
460 | if (fatal_signal_pending(current)) | |
461 | return -ERESTARTNOHAND; | |
1da177e4 LT |
462 | cond_resched(); |
463 | } | |
464 | } | |
465 | return i; | |
466 | } | |
467 | ||
468 | /* | |
b6a2fea3 OW |
469 | * 'copy_strings()' copies argument/environment strings from the old |
470 | * processes's memory to the new process's stack. The call to get_user_pages() | |
471 | * ensures the destination page is created and not swapped out. | |
1da177e4 | 472 | */ |
ba2d0162 | 473 | static int copy_strings(int argc, struct user_arg_ptr argv, |
75c96f85 | 474 | struct linux_binprm *bprm) |
1da177e4 LT |
475 | { |
476 | struct page *kmapped_page = NULL; | |
477 | char *kaddr = NULL; | |
b6a2fea3 | 478 | unsigned long kpos = 0; |
1da177e4 LT |
479 | int ret; |
480 | ||
481 | while (argc-- > 0) { | |
d7627467 | 482 | const char __user *str; |
1da177e4 LT |
483 | int len; |
484 | unsigned long pos; | |
485 | ||
1d1dbf81 ON |
486 | ret = -EFAULT; |
487 | str = get_user_arg_ptr(argv, argc); | |
488 | if (IS_ERR(str)) | |
1da177e4 | 489 | goto out; |
1da177e4 | 490 | |
1d1dbf81 ON |
491 | len = strnlen_user(str, MAX_ARG_STRLEN); |
492 | if (!len) | |
493 | goto out; | |
494 | ||
495 | ret = -E2BIG; | |
496 | if (!valid_arg_len(bprm, len)) | |
1da177e4 | 497 | goto out; |
1da177e4 | 498 | |
b6a2fea3 | 499 | /* We're going to work our way backwords. */ |
1da177e4 | 500 | pos = bprm->p; |
b6a2fea3 OW |
501 | str += len; |
502 | bprm->p -= len; | |
1da177e4 LT |
503 | |
504 | while (len > 0) { | |
1da177e4 | 505 | int offset, bytes_to_copy; |
1da177e4 | 506 | |
9aea5a65 RM |
507 | if (fatal_signal_pending(current)) { |
508 | ret = -ERESTARTNOHAND; | |
509 | goto out; | |
510 | } | |
7993bc1f RM |
511 | cond_resched(); |
512 | ||
1da177e4 | 513 | offset = pos % PAGE_SIZE; |
b6a2fea3 OW |
514 | if (offset == 0) |
515 | offset = PAGE_SIZE; | |
516 | ||
517 | bytes_to_copy = offset; | |
518 | if (bytes_to_copy > len) | |
519 | bytes_to_copy = len; | |
520 | ||
521 | offset -= bytes_to_copy; | |
522 | pos -= bytes_to_copy; | |
523 | str -= bytes_to_copy; | |
524 | len -= bytes_to_copy; | |
525 | ||
526 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { | |
527 | struct page *page; | |
528 | ||
529 | page = get_arg_page(bprm, pos, 1); | |
1da177e4 | 530 | if (!page) { |
b6a2fea3 | 531 | ret = -E2BIG; |
1da177e4 LT |
532 | goto out; |
533 | } | |
1da177e4 | 534 | |
b6a2fea3 OW |
535 | if (kmapped_page) { |
536 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 537 | kunmap(kmapped_page); |
b6a2fea3 OW |
538 | put_arg_page(kmapped_page); |
539 | } | |
1da177e4 LT |
540 | kmapped_page = page; |
541 | kaddr = kmap(kmapped_page); | |
b6a2fea3 OW |
542 | kpos = pos & PAGE_MASK; |
543 | flush_arg_page(bprm, kpos, kmapped_page); | |
1da177e4 | 544 | } |
b6a2fea3 | 545 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
1da177e4 LT |
546 | ret = -EFAULT; |
547 | goto out; | |
548 | } | |
1da177e4 LT |
549 | } |
550 | } | |
551 | ret = 0; | |
552 | out: | |
b6a2fea3 OW |
553 | if (kmapped_page) { |
554 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 555 | kunmap(kmapped_page); |
b6a2fea3 OW |
556 | put_arg_page(kmapped_page); |
557 | } | |
1da177e4 LT |
558 | return ret; |
559 | } | |
560 | ||
561 | /* | |
562 | * Like copy_strings, but get argv and its values from kernel memory. | |
563 | */ | |
ba2d0162 | 564 | int copy_strings_kernel(int argc, const char *const *__argv, |
d7627467 | 565 | struct linux_binprm *bprm) |
1da177e4 LT |
566 | { |
567 | int r; | |
568 | mm_segment_t oldfs = get_fs(); | |
ba2d0162 | 569 | struct user_arg_ptr argv = { |
0e028465 | 570 | .ptr.native = (const char __user *const __user *)__argv, |
ba2d0162 ON |
571 | }; |
572 | ||
1da177e4 | 573 | set_fs(KERNEL_DS); |
ba2d0162 | 574 | r = copy_strings(argc, argv, bprm); |
1da177e4 | 575 | set_fs(oldfs); |
ba2d0162 | 576 | |
1da177e4 LT |
577 | return r; |
578 | } | |
1da177e4 LT |
579 | EXPORT_SYMBOL(copy_strings_kernel); |
580 | ||
581 | #ifdef CONFIG_MMU | |
b6a2fea3 | 582 | |
1da177e4 | 583 | /* |
b6a2fea3 OW |
584 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
585 | * the binfmt code determines where the new stack should reside, we shift it to | |
586 | * its final location. The process proceeds as follows: | |
1da177e4 | 587 | * |
b6a2fea3 OW |
588 | * 1) Use shift to calculate the new vma endpoints. |
589 | * 2) Extend vma to cover both the old and new ranges. This ensures the | |
590 | * arguments passed to subsequent functions are consistent. | |
591 | * 3) Move vma's page tables to the new range. | |
592 | * 4) Free up any cleared pgd range. | |
593 | * 5) Shrink the vma to cover only the new range. | |
1da177e4 | 594 | */ |
b6a2fea3 | 595 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
1da177e4 LT |
596 | { |
597 | struct mm_struct *mm = vma->vm_mm; | |
b6a2fea3 OW |
598 | unsigned long old_start = vma->vm_start; |
599 | unsigned long old_end = vma->vm_end; | |
600 | unsigned long length = old_end - old_start; | |
601 | unsigned long new_start = old_start - shift; | |
602 | unsigned long new_end = old_end - shift; | |
603 | struct mmu_gather *tlb; | |
1da177e4 | 604 | |
b6a2fea3 | 605 | BUG_ON(new_start > new_end); |
1da177e4 | 606 | |
b6a2fea3 OW |
607 | /* |
608 | * ensure there are no vmas between where we want to go | |
609 | * and where we are | |
610 | */ | |
611 | if (vma != find_vma(mm, new_start)) | |
612 | return -EFAULT; | |
613 | ||
614 | /* | |
615 | * cover the whole range: [new_start, old_end) | |
616 | */ | |
5beb4930 RR |
617 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
618 | return -ENOMEM; | |
b6a2fea3 OW |
619 | |
620 | /* | |
621 | * move the page tables downwards, on failure we rely on | |
622 | * process cleanup to remove whatever mess we made. | |
623 | */ | |
624 | if (length != move_page_tables(vma, old_start, | |
625 | vma, new_start, length)) | |
626 | return -ENOMEM; | |
627 | ||
628 | lru_add_drain(); | |
629 | tlb = tlb_gather_mmu(mm, 0); | |
630 | if (new_end > old_start) { | |
631 | /* | |
632 | * when the old and new regions overlap clear from new_end. | |
633 | */ | |
42b77728 | 634 | free_pgd_range(tlb, new_end, old_end, new_end, |
b6a2fea3 OW |
635 | vma->vm_next ? vma->vm_next->vm_start : 0); |
636 | } else { | |
637 | /* | |
638 | * otherwise, clean from old_start; this is done to not touch | |
639 | * the address space in [new_end, old_start) some architectures | |
640 | * have constraints on va-space that make this illegal (IA64) - | |
641 | * for the others its just a little faster. | |
642 | */ | |
42b77728 | 643 | free_pgd_range(tlb, old_start, old_end, new_end, |
b6a2fea3 | 644 | vma->vm_next ? vma->vm_next->vm_start : 0); |
1da177e4 | 645 | } |
b6a2fea3 OW |
646 | tlb_finish_mmu(tlb, new_end, old_end); |
647 | ||
648 | /* | |
5beb4930 | 649 | * Shrink the vma to just the new range. Always succeeds. |
b6a2fea3 OW |
650 | */ |
651 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); | |
652 | ||
653 | return 0; | |
1da177e4 LT |
654 | } |
655 | ||
b6a2fea3 OW |
656 | /* |
657 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, | |
658 | * the stack is optionally relocated, and some extra space is added. | |
659 | */ | |
1da177e4 LT |
660 | int setup_arg_pages(struct linux_binprm *bprm, |
661 | unsigned long stack_top, | |
662 | int executable_stack) | |
663 | { | |
b6a2fea3 OW |
664 | unsigned long ret; |
665 | unsigned long stack_shift; | |
1da177e4 | 666 | struct mm_struct *mm = current->mm; |
b6a2fea3 OW |
667 | struct vm_area_struct *vma = bprm->vma; |
668 | struct vm_area_struct *prev = NULL; | |
669 | unsigned long vm_flags; | |
670 | unsigned long stack_base; | |
803bf5ec MN |
671 | unsigned long stack_size; |
672 | unsigned long stack_expand; | |
673 | unsigned long rlim_stack; | |
1da177e4 LT |
674 | |
675 | #ifdef CONFIG_STACK_GROWSUP | |
1da177e4 | 676 | /* Limit stack size to 1GB */ |
d554ed89 | 677 | stack_base = rlimit_max(RLIMIT_STACK); |
1da177e4 LT |
678 | if (stack_base > (1 << 30)) |
679 | stack_base = 1 << 30; | |
1da177e4 | 680 | |
b6a2fea3 OW |
681 | /* Make sure we didn't let the argument array grow too large. */ |
682 | if (vma->vm_end - vma->vm_start > stack_base) | |
683 | return -ENOMEM; | |
1da177e4 | 684 | |
b6a2fea3 | 685 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
1da177e4 | 686 | |
b6a2fea3 OW |
687 | stack_shift = vma->vm_start - stack_base; |
688 | mm->arg_start = bprm->p - stack_shift; | |
689 | bprm->p = vma->vm_end - stack_shift; | |
1da177e4 | 690 | #else |
b6a2fea3 OW |
691 | stack_top = arch_align_stack(stack_top); |
692 | stack_top = PAGE_ALIGN(stack_top); | |
1b528181 RM |
693 | |
694 | if (unlikely(stack_top < mmap_min_addr) || | |
695 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) | |
696 | return -ENOMEM; | |
697 | ||
b6a2fea3 OW |
698 | stack_shift = vma->vm_end - stack_top; |
699 | ||
700 | bprm->p -= stack_shift; | |
1da177e4 | 701 | mm->arg_start = bprm->p; |
1da177e4 LT |
702 | #endif |
703 | ||
1da177e4 | 704 | if (bprm->loader) |
b6a2fea3 OW |
705 | bprm->loader -= stack_shift; |
706 | bprm->exec -= stack_shift; | |
1da177e4 | 707 | |
1da177e4 | 708 | down_write(&mm->mmap_sem); |
96a8e13e | 709 | vm_flags = VM_STACK_FLAGS; |
b6a2fea3 OW |
710 | |
711 | /* | |
712 | * Adjust stack execute permissions; explicitly enable for | |
713 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone | |
714 | * (arch default) otherwise. | |
715 | */ | |
716 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
717 | vm_flags |= VM_EXEC; | |
718 | else if (executable_stack == EXSTACK_DISABLE_X) | |
719 | vm_flags &= ~VM_EXEC; | |
720 | vm_flags |= mm->def_flags; | |
a8bef8ff | 721 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
b6a2fea3 OW |
722 | |
723 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, | |
724 | vm_flags); | |
725 | if (ret) | |
726 | goto out_unlock; | |
727 | BUG_ON(prev != vma); | |
728 | ||
729 | /* Move stack pages down in memory. */ | |
730 | if (stack_shift) { | |
731 | ret = shift_arg_pages(vma, stack_shift); | |
fc63cf23 AB |
732 | if (ret) |
733 | goto out_unlock; | |
1da177e4 LT |
734 | } |
735 | ||
a8bef8ff MG |
736 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
737 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; | |
738 | ||
5ef097dd | 739 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
803bf5ec MN |
740 | stack_size = vma->vm_end - vma->vm_start; |
741 | /* | |
742 | * Align this down to a page boundary as expand_stack | |
743 | * will align it up. | |
744 | */ | |
745 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; | |
b6a2fea3 | 746 | #ifdef CONFIG_STACK_GROWSUP |
803bf5ec MN |
747 | if (stack_size + stack_expand > rlim_stack) |
748 | stack_base = vma->vm_start + rlim_stack; | |
749 | else | |
750 | stack_base = vma->vm_end + stack_expand; | |
b6a2fea3 | 751 | #else |
803bf5ec MN |
752 | if (stack_size + stack_expand > rlim_stack) |
753 | stack_base = vma->vm_end - rlim_stack; | |
754 | else | |
755 | stack_base = vma->vm_start - stack_expand; | |
b6a2fea3 | 756 | #endif |
3af9e859 | 757 | current->mm->start_stack = bprm->p; |
b6a2fea3 OW |
758 | ret = expand_stack(vma, stack_base); |
759 | if (ret) | |
760 | ret = -EFAULT; | |
761 | ||
762 | out_unlock: | |
1da177e4 | 763 | up_write(&mm->mmap_sem); |
fc63cf23 | 764 | return ret; |
1da177e4 | 765 | } |
1da177e4 LT |
766 | EXPORT_SYMBOL(setup_arg_pages); |
767 | ||
1da177e4 LT |
768 | #endif /* CONFIG_MMU */ |
769 | ||
770 | struct file *open_exec(const char *name) | |
771 | { | |
1da177e4 | 772 | struct file *file; |
e56b6a5d | 773 | int err; |
47c805dc AV |
774 | static const struct open_flags open_exec_flags = { |
775 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
776 | .acc_mode = MAY_EXEC | MAY_OPEN, | |
777 | .intent = LOOKUP_OPEN | |
778 | }; | |
1da177e4 | 779 | |
47c805dc | 780 | file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); |
6e8341a1 | 781 | if (IS_ERR(file)) |
e56b6a5d CH |
782 | goto out; |
783 | ||
784 | err = -EACCES; | |
6e8341a1 AV |
785 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
786 | goto exit; | |
e56b6a5d | 787 | |
6e8341a1 AV |
788 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
789 | goto exit; | |
e56b6a5d | 790 | |
2a12a9d7 | 791 | fsnotify_open(file); |
6110e3ab | 792 | |
e56b6a5d | 793 | err = deny_write_access(file); |
6e8341a1 AV |
794 | if (err) |
795 | goto exit; | |
1da177e4 | 796 | |
6e8341a1 | 797 | out: |
e56b6a5d CH |
798 | return file; |
799 | ||
6e8341a1 AV |
800 | exit: |
801 | fput(file); | |
e56b6a5d CH |
802 | return ERR_PTR(err); |
803 | } | |
1da177e4 LT |
804 | EXPORT_SYMBOL(open_exec); |
805 | ||
6777d773 MZ |
806 | int kernel_read(struct file *file, loff_t offset, |
807 | char *addr, unsigned long count) | |
1da177e4 LT |
808 | { |
809 | mm_segment_t old_fs; | |
810 | loff_t pos = offset; | |
811 | int result; | |
812 | ||
813 | old_fs = get_fs(); | |
814 | set_fs(get_ds()); | |
815 | /* The cast to a user pointer is valid due to the set_fs() */ | |
816 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
817 | set_fs(old_fs); | |
818 | return result; | |
819 | } | |
820 | ||
821 | EXPORT_SYMBOL(kernel_read); | |
822 | ||
823 | static int exec_mmap(struct mm_struct *mm) | |
824 | { | |
825 | struct task_struct *tsk; | |
826 | struct mm_struct * old_mm, *active_mm; | |
827 | ||
828 | /* Notify parent that we're no longer interested in the old VM */ | |
829 | tsk = current; | |
830 | old_mm = current->mm; | |
34e55232 | 831 | sync_mm_rss(tsk, old_mm); |
1da177e4 LT |
832 | mm_release(tsk, old_mm); |
833 | ||
834 | if (old_mm) { | |
835 | /* | |
836 | * Make sure that if there is a core dump in progress | |
837 | * for the old mm, we get out and die instead of going | |
838 | * through with the exec. We must hold mmap_sem around | |
999d9fc1 | 839 | * checking core_state and changing tsk->mm. |
1da177e4 LT |
840 | */ |
841 | down_read(&old_mm->mmap_sem); | |
999d9fc1 | 842 | if (unlikely(old_mm->core_state)) { |
1da177e4 LT |
843 | up_read(&old_mm->mmap_sem); |
844 | return -EINTR; | |
845 | } | |
846 | } | |
847 | task_lock(tsk); | |
848 | active_mm = tsk->active_mm; | |
849 | tsk->mm = mm; | |
850 | tsk->active_mm = mm; | |
851 | activate_mm(active_mm, mm); | |
3d5992d2 YH |
852 | if (old_mm && tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { |
853 | atomic_dec(&old_mm->oom_disable_count); | |
854 | atomic_inc(&tsk->mm->oom_disable_count); | |
855 | } | |
1da177e4 LT |
856 | task_unlock(tsk); |
857 | arch_pick_mmap_layout(mm); | |
858 | if (old_mm) { | |
859 | up_read(&old_mm->mmap_sem); | |
7dddb12c | 860 | BUG_ON(active_mm != old_mm); |
31a78f23 | 861 | mm_update_next_owner(old_mm); |
1da177e4 LT |
862 | mmput(old_mm); |
863 | return 0; | |
864 | } | |
865 | mmdrop(active_mm); | |
866 | return 0; | |
867 | } | |
868 | ||
869 | /* | |
870 | * This function makes sure the current process has its own signal table, | |
871 | * so that flush_signal_handlers can later reset the handlers without | |
872 | * disturbing other processes. (Other processes might share the signal | |
873 | * table via the CLONE_SIGHAND option to clone().) | |
874 | */ | |
858119e1 | 875 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
876 | { |
877 | struct signal_struct *sig = tsk->signal; | |
b2c903b8 | 878 | struct sighand_struct *oldsighand = tsk->sighand; |
1da177e4 | 879 | spinlock_t *lock = &oldsighand->siglock; |
1da177e4 | 880 | |
aafe6c2a | 881 | if (thread_group_empty(tsk)) |
1da177e4 LT |
882 | goto no_thread_group; |
883 | ||
884 | /* | |
885 | * Kill all other threads in the thread group. | |
1da177e4 | 886 | */ |
1da177e4 | 887 | spin_lock_irq(lock); |
ed5d2cac | 888 | if (signal_group_exit(sig)) { |
1da177e4 LT |
889 | /* |
890 | * Another group action in progress, just | |
891 | * return so that the signal is processed. | |
892 | */ | |
893 | spin_unlock_irq(lock); | |
1da177e4 LT |
894 | return -EAGAIN; |
895 | } | |
d344193a | 896 | |
ed5d2cac | 897 | sig->group_exit_task = tsk; |
d344193a ON |
898 | sig->notify_count = zap_other_threads(tsk); |
899 | if (!thread_group_leader(tsk)) | |
900 | sig->notify_count--; | |
1da177e4 | 901 | |
d344193a | 902 | while (sig->notify_count) { |
1da177e4 LT |
903 | __set_current_state(TASK_UNINTERRUPTIBLE); |
904 | spin_unlock_irq(lock); | |
905 | schedule(); | |
906 | spin_lock_irq(lock); | |
907 | } | |
1da177e4 LT |
908 | spin_unlock_irq(lock); |
909 | ||
910 | /* | |
911 | * At this point all other threads have exited, all we have to | |
912 | * do is to wait for the thread group leader to become inactive, | |
913 | * and to assume its PID: | |
914 | */ | |
aafe6c2a | 915 | if (!thread_group_leader(tsk)) { |
8187926b | 916 | struct task_struct *leader = tsk->group_leader; |
6db840fa | 917 | |
2800d8d1 | 918 | sig->notify_count = -1; /* for exit_notify() */ |
6db840fa ON |
919 | for (;;) { |
920 | write_lock_irq(&tasklist_lock); | |
921 | if (likely(leader->exit_state)) | |
922 | break; | |
923 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
924 | write_unlock_irq(&tasklist_lock); | |
925 | schedule(); | |
926 | } | |
1da177e4 | 927 | |
f5e90281 RM |
928 | /* |
929 | * The only record we have of the real-time age of a | |
930 | * process, regardless of execs it's done, is start_time. | |
931 | * All the past CPU time is accumulated in signal_struct | |
932 | * from sister threads now dead. But in this non-leader | |
933 | * exec, nothing survives from the original leader thread, | |
934 | * whose birth marks the true age of this process now. | |
935 | * When we take on its identity by switching to its PID, we | |
936 | * also take its birthdate (always earlier than our own). | |
937 | */ | |
aafe6c2a | 938 | tsk->start_time = leader->start_time; |
f5e90281 | 939 | |
bac0abd6 PE |
940 | BUG_ON(!same_thread_group(leader, tsk)); |
941 | BUG_ON(has_group_leader_pid(tsk)); | |
1da177e4 LT |
942 | /* |
943 | * An exec() starts a new thread group with the | |
944 | * TGID of the previous thread group. Rehash the | |
945 | * two threads with a switched PID, and release | |
946 | * the former thread group leader: | |
947 | */ | |
d73d6529 EB |
948 | |
949 | /* Become a process group leader with the old leader's pid. | |
c18258c6 EB |
950 | * The old leader becomes a thread of the this thread group. |
951 | * Note: The old leader also uses this pid until release_task | |
d73d6529 EB |
952 | * is called. Odd but simple and correct. |
953 | */ | |
aafe6c2a EB |
954 | detach_pid(tsk, PIDTYPE_PID); |
955 | tsk->pid = leader->pid; | |
3743ca05 | 956 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
aafe6c2a EB |
957 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
958 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
9cd80bbb | 959 | |
aafe6c2a | 960 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
9cd80bbb | 961 | list_replace_init(&leader->sibling, &tsk->sibling); |
1da177e4 | 962 | |
aafe6c2a EB |
963 | tsk->group_leader = tsk; |
964 | leader->group_leader = tsk; | |
de12a787 | 965 | |
aafe6c2a | 966 | tsk->exit_signal = SIGCHLD; |
962b564c ON |
967 | |
968 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
969 | leader->exit_state = EXIT_DEAD; | |
1da177e4 | 970 | write_unlock_irq(&tasklist_lock); |
8187926b ON |
971 | |
972 | release_task(leader); | |
ed5d2cac | 973 | } |
1da177e4 | 974 | |
6db840fa ON |
975 | sig->group_exit_task = NULL; |
976 | sig->notify_count = 0; | |
1da177e4 LT |
977 | |
978 | no_thread_group: | |
1f10206c JP |
979 | if (current->mm) |
980 | setmax_mm_hiwater_rss(&sig->maxrss, current->mm); | |
981 | ||
1da177e4 | 982 | exit_itimers(sig); |
cbaffba1 | 983 | flush_itimer_signals(); |
329f7dba | 984 | |
b2c903b8 ON |
985 | if (atomic_read(&oldsighand->count) != 1) { |
986 | struct sighand_struct *newsighand; | |
1da177e4 | 987 | /* |
b2c903b8 ON |
988 | * This ->sighand is shared with the CLONE_SIGHAND |
989 | * but not CLONE_THREAD task, switch to the new one. | |
1da177e4 | 990 | */ |
b2c903b8 ON |
991 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
992 | if (!newsighand) | |
993 | return -ENOMEM; | |
994 | ||
1da177e4 LT |
995 | atomic_set(&newsighand->count, 1); |
996 | memcpy(newsighand->action, oldsighand->action, | |
997 | sizeof(newsighand->action)); | |
998 | ||
999 | write_lock_irq(&tasklist_lock); | |
1000 | spin_lock(&oldsighand->siglock); | |
aafe6c2a | 1001 | rcu_assign_pointer(tsk->sighand, newsighand); |
1da177e4 LT |
1002 | spin_unlock(&oldsighand->siglock); |
1003 | write_unlock_irq(&tasklist_lock); | |
1004 | ||
fba2afaa | 1005 | __cleanup_sighand(oldsighand); |
1da177e4 LT |
1006 | } |
1007 | ||
aafe6c2a | 1008 | BUG_ON(!thread_group_leader(tsk)); |
1da177e4 LT |
1009 | return 0; |
1010 | } | |
0840a90d | 1011 | |
1da177e4 LT |
1012 | /* |
1013 | * These functions flushes out all traces of the currently running executable | |
1014 | * so that a new one can be started | |
1015 | */ | |
858119e1 | 1016 | static void flush_old_files(struct files_struct * files) |
1da177e4 LT |
1017 | { |
1018 | long j = -1; | |
badf1662 | 1019 | struct fdtable *fdt; |
1da177e4 LT |
1020 | |
1021 | spin_lock(&files->file_lock); | |
1022 | for (;;) { | |
1023 | unsigned long set, i; | |
1024 | ||
1025 | j++; | |
1026 | i = j * __NFDBITS; | |
badf1662 | 1027 | fdt = files_fdtable(files); |
bbea9f69 | 1028 | if (i >= fdt->max_fds) |
1da177e4 | 1029 | break; |
badf1662 | 1030 | set = fdt->close_on_exec->fds_bits[j]; |
1da177e4 LT |
1031 | if (!set) |
1032 | continue; | |
badf1662 | 1033 | fdt->close_on_exec->fds_bits[j] = 0; |
1da177e4 LT |
1034 | spin_unlock(&files->file_lock); |
1035 | for ( ; set ; i++,set >>= 1) { | |
1036 | if (set & 1) { | |
1037 | sys_close(i); | |
1038 | } | |
1039 | } | |
1040 | spin_lock(&files->file_lock); | |
1041 | ||
1042 | } | |
1043 | spin_unlock(&files->file_lock); | |
1044 | } | |
1045 | ||
59714d65 | 1046 | char *get_task_comm(char *buf, struct task_struct *tsk) |
1da177e4 LT |
1047 | { |
1048 | /* buf must be at least sizeof(tsk->comm) in size */ | |
1049 | task_lock(tsk); | |
1050 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
1051 | task_unlock(tsk); | |
59714d65 | 1052 | return buf; |
1da177e4 | 1053 | } |
7d74f492 | 1054 | EXPORT_SYMBOL_GPL(get_task_comm); |
1da177e4 LT |
1055 | |
1056 | void set_task_comm(struct task_struct *tsk, char *buf) | |
1057 | { | |
1058 | task_lock(tsk); | |
4614a696 | 1059 | |
1060 | /* | |
1061 | * Threads may access current->comm without holding | |
1062 | * the task lock, so write the string carefully. | |
1063 | * Readers without a lock may see incomplete new | |
1064 | * names but are safe from non-terminating string reads. | |
1065 | */ | |
1066 | memset(tsk->comm, 0, TASK_COMM_LEN); | |
1067 | wmb(); | |
1da177e4 LT |
1068 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
1069 | task_unlock(tsk); | |
cdd6c482 | 1070 | perf_event_comm(tsk); |
1da177e4 LT |
1071 | } |
1072 | ||
1073 | int flush_old_exec(struct linux_binprm * bprm) | |
1074 | { | |
221af7f8 | 1075 | int retval; |
1da177e4 LT |
1076 | |
1077 | /* | |
1078 | * Make sure we have a private signal table and that | |
1079 | * we are unassociated from the previous thread group. | |
1080 | */ | |
1081 | retval = de_thread(current); | |
1082 | if (retval) | |
1083 | goto out; | |
1084 | ||
925d1c40 MH |
1085 | set_mm_exe_file(bprm->mm, bprm->file); |
1086 | ||
1da177e4 LT |
1087 | /* |
1088 | * Release all of the old mmap stuff | |
1089 | */ | |
3c77f845 | 1090 | acct_arg_size(bprm, 0); |
1da177e4 LT |
1091 | retval = exec_mmap(bprm->mm); |
1092 | if (retval) | |
fd8328be | 1093 | goto out; |
1da177e4 LT |
1094 | |
1095 | bprm->mm = NULL; /* We're using it now */ | |
7ab02af4 | 1096 | |
98391cf4 | 1097 | current->flags &= ~(PF_RANDOMIZE | PF_KTHREAD); |
7ab02af4 LT |
1098 | flush_thread(); |
1099 | current->personality &= ~bprm->per_clear; | |
1100 | ||
221af7f8 LT |
1101 | return 0; |
1102 | ||
1103 | out: | |
1104 | return retval; | |
1105 | } | |
1106 | EXPORT_SYMBOL(flush_old_exec); | |
1107 | ||
1108 | void setup_new_exec(struct linux_binprm * bprm) | |
1109 | { | |
1110 | int i, ch; | |
d7627467 | 1111 | const char *name; |
221af7f8 LT |
1112 | char tcomm[sizeof(current->comm)]; |
1113 | ||
1114 | arch_pick_mmap_layout(current->mm); | |
1da177e4 LT |
1115 | |
1116 | /* This is the point of no return */ | |
1da177e4 LT |
1117 | current->sas_ss_sp = current->sas_ss_size = 0; |
1118 | ||
da9592ed | 1119 | if (current_euid() == current_uid() && current_egid() == current_gid()) |
6c5d5238 | 1120 | set_dumpable(current->mm, 1); |
d6e71144 | 1121 | else |
6c5d5238 | 1122 | set_dumpable(current->mm, suid_dumpable); |
d6e71144 | 1123 | |
1da177e4 | 1124 | name = bprm->filename; |
36772092 PBG |
1125 | |
1126 | /* Copies the binary name from after last slash */ | |
1da177e4 LT |
1127 | for (i=0; (ch = *(name++)) != '\0';) { |
1128 | if (ch == '/') | |
36772092 | 1129 | i = 0; /* overwrite what we wrote */ |
1da177e4 LT |
1130 | else |
1131 | if (i < (sizeof(tcomm) - 1)) | |
1132 | tcomm[i++] = ch; | |
1133 | } | |
1134 | tcomm[i] = '\0'; | |
1135 | set_task_comm(current, tcomm); | |
1136 | ||
0551fbd2 BH |
1137 | /* Set the new mm task size. We have to do that late because it may |
1138 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
1139 | * some architectures like powerpc | |
1140 | */ | |
1141 | current->mm->task_size = TASK_SIZE; | |
1142 | ||
a6f76f23 DH |
1143 | /* install the new credentials */ |
1144 | if (bprm->cred->uid != current_euid() || | |
1145 | bprm->cred->gid != current_egid()) { | |
d2d56c5f MH |
1146 | current->pdeath_signal = 0; |
1147 | } else if (file_permission(bprm->file, MAY_READ) || | |
a6f76f23 | 1148 | bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) { |
6c5d5238 | 1149 | set_dumpable(current->mm, suid_dumpable); |
1da177e4 LT |
1150 | } |
1151 | ||
f65cb45c IM |
1152 | /* |
1153 | * Flush performance counters when crossing a | |
1154 | * security domain: | |
1155 | */ | |
1156 | if (!get_dumpable(current->mm)) | |
cdd6c482 | 1157 | perf_event_exit_task(current); |
f65cb45c | 1158 | |
1da177e4 LT |
1159 | /* An exec changes our domain. We are no longer part of the thread |
1160 | group */ | |
1161 | ||
1162 | current->self_exec_id++; | |
1163 | ||
1164 | flush_signal_handlers(current, 0); | |
1165 | flush_old_files(current->files); | |
1da177e4 | 1166 | } |
221af7f8 | 1167 | EXPORT_SYMBOL(setup_new_exec); |
1da177e4 | 1168 | |
a2a8474c ON |
1169 | /* |
1170 | * Prepare credentials and lock ->cred_guard_mutex. | |
1171 | * install_exec_creds() commits the new creds and drops the lock. | |
1172 | * Or, if exec fails before, free_bprm() should release ->cred and | |
1173 | * and unlock. | |
1174 | */ | |
1175 | int prepare_bprm_creds(struct linux_binprm *bprm) | |
1176 | { | |
9b1bf12d | 1177 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
a2a8474c ON |
1178 | return -ERESTARTNOINTR; |
1179 | ||
1180 | bprm->cred = prepare_exec_creds(); | |
1181 | if (likely(bprm->cred)) | |
1182 | return 0; | |
1183 | ||
9b1bf12d | 1184 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1185 | return -ENOMEM; |
1186 | } | |
1187 | ||
1188 | void free_bprm(struct linux_binprm *bprm) | |
1189 | { | |
1190 | free_arg_pages(bprm); | |
1191 | if (bprm->cred) { | |
9b1bf12d | 1192 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1193 | abort_creds(bprm->cred); |
1194 | } | |
1195 | kfree(bprm); | |
1196 | } | |
1197 | ||
a6f76f23 DH |
1198 | /* |
1199 | * install the new credentials for this executable | |
1200 | */ | |
1201 | void install_exec_creds(struct linux_binprm *bprm) | |
1202 | { | |
1203 | security_bprm_committing_creds(bprm); | |
1204 | ||
1205 | commit_creds(bprm->cred); | |
1206 | bprm->cred = NULL; | |
a2a8474c ON |
1207 | /* |
1208 | * cred_guard_mutex must be held at least to this point to prevent | |
a6f76f23 | 1209 | * ptrace_attach() from altering our determination of the task's |
a2a8474c ON |
1210 | * credentials; any time after this it may be unlocked. |
1211 | */ | |
a6f76f23 | 1212 | security_bprm_committed_creds(bprm); |
9b1bf12d | 1213 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a6f76f23 DH |
1214 | } |
1215 | EXPORT_SYMBOL(install_exec_creds); | |
1216 | ||
1217 | /* | |
1218 | * determine how safe it is to execute the proposed program | |
9b1bf12d | 1219 | * - the caller must hold ->cred_guard_mutex to protect against |
a6f76f23 DH |
1220 | * PTRACE_ATTACH |
1221 | */ | |
498052bb | 1222 | int check_unsafe_exec(struct linux_binprm *bprm) |
a6f76f23 | 1223 | { |
0bf2f3ae | 1224 | struct task_struct *p = current, *t; |
f1191b50 | 1225 | unsigned n_fs; |
498052bb | 1226 | int res = 0; |
a6f76f23 DH |
1227 | |
1228 | bprm->unsafe = tracehook_unsafe_exec(p); | |
1229 | ||
0bf2f3ae | 1230 | n_fs = 1; |
2a4419b5 | 1231 | spin_lock(&p->fs->lock); |
437f7fdb | 1232 | rcu_read_lock(); |
0bf2f3ae DH |
1233 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
1234 | if (t->fs == p->fs) | |
1235 | n_fs++; | |
0bf2f3ae | 1236 | } |
437f7fdb | 1237 | rcu_read_unlock(); |
0bf2f3ae | 1238 | |
f1191b50 | 1239 | if (p->fs->users > n_fs) { |
a6f76f23 | 1240 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
498052bb | 1241 | } else { |
8c652f96 ON |
1242 | res = -EAGAIN; |
1243 | if (!p->fs->in_exec) { | |
1244 | p->fs->in_exec = 1; | |
1245 | res = 1; | |
1246 | } | |
498052bb | 1247 | } |
2a4419b5 | 1248 | spin_unlock(&p->fs->lock); |
498052bb AV |
1249 | |
1250 | return res; | |
a6f76f23 DH |
1251 | } |
1252 | ||
1da177e4 LT |
1253 | /* |
1254 | * Fill the binprm structure from the inode. | |
1255 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
a6f76f23 DH |
1256 | * |
1257 | * This may be called multiple times for binary chains (scripts for example). | |
1da177e4 LT |
1258 | */ |
1259 | int prepare_binprm(struct linux_binprm *bprm) | |
1260 | { | |
a6f76f23 | 1261 | umode_t mode; |
0f7fc9e4 | 1262 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
1263 | int retval; |
1264 | ||
1265 | mode = inode->i_mode; | |
1da177e4 LT |
1266 | if (bprm->file->f_op == NULL) |
1267 | return -EACCES; | |
1268 | ||
a6f76f23 DH |
1269 | /* clear any previous set[ug]id data from a previous binary */ |
1270 | bprm->cred->euid = current_euid(); | |
1271 | bprm->cred->egid = current_egid(); | |
1da177e4 | 1272 | |
a6f76f23 | 1273 | if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
1da177e4 LT |
1274 | /* Set-uid? */ |
1275 | if (mode & S_ISUID) { | |
a6f76f23 DH |
1276 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1277 | bprm->cred->euid = inode->i_uid; | |
1da177e4 LT |
1278 | } |
1279 | ||
1280 | /* Set-gid? */ | |
1281 | /* | |
1282 | * If setgid is set but no group execute bit then this | |
1283 | * is a candidate for mandatory locking, not a setgid | |
1284 | * executable. | |
1285 | */ | |
1286 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
a6f76f23 DH |
1287 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1288 | bprm->cred->egid = inode->i_gid; | |
1da177e4 LT |
1289 | } |
1290 | } | |
1291 | ||
1292 | /* fill in binprm security blob */ | |
a6f76f23 | 1293 | retval = security_bprm_set_creds(bprm); |
1da177e4 LT |
1294 | if (retval) |
1295 | return retval; | |
a6f76f23 | 1296 | bprm->cred_prepared = 1; |
1da177e4 | 1297 | |
a6f76f23 DH |
1298 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
1299 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); | |
1da177e4 LT |
1300 | } |
1301 | ||
1302 | EXPORT_SYMBOL(prepare_binprm); | |
1303 | ||
4fc75ff4 NP |
1304 | /* |
1305 | * Arguments are '\0' separated strings found at the location bprm->p | |
1306 | * points to; chop off the first by relocating brpm->p to right after | |
1307 | * the first '\0' encountered. | |
1308 | */ | |
b6a2fea3 | 1309 | int remove_arg_zero(struct linux_binprm *bprm) |
1da177e4 | 1310 | { |
b6a2fea3 OW |
1311 | int ret = 0; |
1312 | unsigned long offset; | |
1313 | char *kaddr; | |
1314 | struct page *page; | |
4fc75ff4 | 1315 | |
b6a2fea3 OW |
1316 | if (!bprm->argc) |
1317 | return 0; | |
1da177e4 | 1318 | |
b6a2fea3 OW |
1319 | do { |
1320 | offset = bprm->p & ~PAGE_MASK; | |
1321 | page = get_arg_page(bprm, bprm->p, 0); | |
1322 | if (!page) { | |
1323 | ret = -EFAULT; | |
1324 | goto out; | |
1325 | } | |
1326 | kaddr = kmap_atomic(page, KM_USER0); | |
4fc75ff4 | 1327 | |
b6a2fea3 OW |
1328 | for (; offset < PAGE_SIZE && kaddr[offset]; |
1329 | offset++, bprm->p++) | |
1330 | ; | |
4fc75ff4 | 1331 | |
b6a2fea3 OW |
1332 | kunmap_atomic(kaddr, KM_USER0); |
1333 | put_arg_page(page); | |
4fc75ff4 | 1334 | |
b6a2fea3 OW |
1335 | if (offset == PAGE_SIZE) |
1336 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); | |
1337 | } while (offset == PAGE_SIZE); | |
4fc75ff4 | 1338 | |
b6a2fea3 OW |
1339 | bprm->p++; |
1340 | bprm->argc--; | |
1341 | ret = 0; | |
4fc75ff4 | 1342 | |
b6a2fea3 OW |
1343 | out: |
1344 | return ret; | |
1da177e4 | 1345 | } |
1da177e4 LT |
1346 | EXPORT_SYMBOL(remove_arg_zero); |
1347 | ||
1348 | /* | |
1349 | * cycle the list of binary formats handler, until one recognizes the image | |
1350 | */ | |
1351 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1352 | { | |
85f33466 | 1353 | unsigned int depth = bprm->recursion_depth; |
1da177e4 LT |
1354 | int try,retval; |
1355 | struct linux_binfmt *fmt; | |
1da177e4 | 1356 | |
1da177e4 LT |
1357 | retval = security_bprm_check(bprm); |
1358 | if (retval) | |
1359 | return retval; | |
1360 | ||
1361 | /* kernel module loader fixup */ | |
1362 | /* so we don't try to load run modprobe in kernel space. */ | |
1363 | set_fs(USER_DS); | |
473ae30b AV |
1364 | |
1365 | retval = audit_bprm(bprm); | |
1366 | if (retval) | |
1367 | return retval; | |
1368 | ||
1da177e4 LT |
1369 | retval = -ENOENT; |
1370 | for (try=0; try<2; try++) { | |
1371 | read_lock(&binfmt_lock); | |
e4dc1b14 | 1372 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
1373 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
1374 | if (!fn) | |
1375 | continue; | |
1376 | if (!try_module_get(fmt->module)) | |
1377 | continue; | |
1378 | read_unlock(&binfmt_lock); | |
1379 | retval = fn(bprm, regs); | |
85f33466 RM |
1380 | /* |
1381 | * Restore the depth counter to its starting value | |
1382 | * in this call, so we don't have to rely on every | |
1383 | * load_binary function to restore it on return. | |
1384 | */ | |
1385 | bprm->recursion_depth = depth; | |
1da177e4 | 1386 | if (retval >= 0) { |
85f33466 RM |
1387 | if (depth == 0) |
1388 | tracehook_report_exec(fmt, bprm, regs); | |
1da177e4 LT |
1389 | put_binfmt(fmt); |
1390 | allow_write_access(bprm->file); | |
1391 | if (bprm->file) | |
1392 | fput(bprm->file); | |
1393 | bprm->file = NULL; | |
1394 | current->did_exec = 1; | |
9f46080c | 1395 | proc_exec_connector(current); |
1da177e4 LT |
1396 | return retval; |
1397 | } | |
1398 | read_lock(&binfmt_lock); | |
1399 | put_binfmt(fmt); | |
1400 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1401 | break; | |
1402 | if (!bprm->file) { | |
1403 | read_unlock(&binfmt_lock); | |
1404 | return retval; | |
1405 | } | |
1406 | } | |
1407 | read_unlock(&binfmt_lock); | |
1408 | if (retval != -ENOEXEC || bprm->mm == NULL) { | |
1409 | break; | |
5f4123be JB |
1410 | #ifdef CONFIG_MODULES |
1411 | } else { | |
1da177e4 LT |
1412 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
1413 | if (printable(bprm->buf[0]) && | |
1414 | printable(bprm->buf[1]) && | |
1415 | printable(bprm->buf[2]) && | |
1416 | printable(bprm->buf[3])) | |
1417 | break; /* -ENOEXEC */ | |
1418 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); | |
1419 | #endif | |
1420 | } | |
1421 | } | |
1422 | return retval; | |
1423 | } | |
1424 | ||
1425 | EXPORT_SYMBOL(search_binary_handler); | |
1426 | ||
1427 | /* | |
1428 | * sys_execve() executes a new program. | |
1429 | */ | |
ba2d0162 ON |
1430 | static int do_execve_common(const char *filename, |
1431 | struct user_arg_ptr argv, | |
1432 | struct user_arg_ptr envp, | |
1433 | struct pt_regs *regs) | |
1da177e4 LT |
1434 | { |
1435 | struct linux_binprm *bprm; | |
1436 | struct file *file; | |
3b125388 | 1437 | struct files_struct *displaced; |
8c652f96 | 1438 | bool clear_in_exec; |
1da177e4 | 1439 | int retval; |
1da177e4 | 1440 | |
3b125388 | 1441 | retval = unshare_files(&displaced); |
fd8328be AV |
1442 | if (retval) |
1443 | goto out_ret; | |
1444 | ||
1da177e4 | 1445 | retval = -ENOMEM; |
11b0b5ab | 1446 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1da177e4 | 1447 | if (!bprm) |
fd8328be | 1448 | goto out_files; |
1da177e4 | 1449 | |
a2a8474c ON |
1450 | retval = prepare_bprm_creds(bprm); |
1451 | if (retval) | |
a6f76f23 | 1452 | goto out_free; |
498052bb AV |
1453 | |
1454 | retval = check_unsafe_exec(bprm); | |
8c652f96 | 1455 | if (retval < 0) |
a2a8474c | 1456 | goto out_free; |
8c652f96 | 1457 | clear_in_exec = retval; |
a2a8474c | 1458 | current->in_execve = 1; |
a6f76f23 | 1459 | |
1da177e4 LT |
1460 | file = open_exec(filename); |
1461 | retval = PTR_ERR(file); | |
1462 | if (IS_ERR(file)) | |
498052bb | 1463 | goto out_unmark; |
1da177e4 LT |
1464 | |
1465 | sched_exec(); | |
1466 | ||
1da177e4 LT |
1467 | bprm->file = file; |
1468 | bprm->filename = filename; | |
1469 | bprm->interp = filename; | |
1da177e4 | 1470 | |
b6a2fea3 OW |
1471 | retval = bprm_mm_init(bprm); |
1472 | if (retval) | |
1473 | goto out_file; | |
1da177e4 | 1474 | |
b6a2fea3 | 1475 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
1da177e4 | 1476 | if ((retval = bprm->argc) < 0) |
a6f76f23 | 1477 | goto out; |
1da177e4 | 1478 | |
b6a2fea3 | 1479 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
1da177e4 | 1480 | if ((retval = bprm->envc) < 0) |
1da177e4 LT |
1481 | goto out; |
1482 | ||
1483 | retval = prepare_binprm(bprm); | |
1484 | if (retval < 0) | |
1485 | goto out; | |
1486 | ||
1487 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1488 | if (retval < 0) | |
1489 | goto out; | |
1490 | ||
1491 | bprm->exec = bprm->p; | |
1492 | retval = copy_strings(bprm->envc, envp, bprm); | |
1493 | if (retval < 0) | |
1494 | goto out; | |
1495 | ||
1496 | retval = copy_strings(bprm->argc, argv, bprm); | |
1497 | if (retval < 0) | |
1498 | goto out; | |
1499 | ||
1500 | retval = search_binary_handler(bprm,regs); | |
a6f76f23 DH |
1501 | if (retval < 0) |
1502 | goto out; | |
1da177e4 | 1503 | |
a6f76f23 | 1504 | /* execve succeeded */ |
498052bb | 1505 | current->fs->in_exec = 0; |
f9ce1f1c | 1506 | current->in_execve = 0; |
a6f76f23 DH |
1507 | acct_update_integrals(current); |
1508 | free_bprm(bprm); | |
1509 | if (displaced) | |
1510 | put_files_struct(displaced); | |
1511 | return retval; | |
1da177e4 | 1512 | |
a6f76f23 | 1513 | out: |
3c77f845 ON |
1514 | if (bprm->mm) { |
1515 | acct_arg_size(bprm, 0); | |
1516 | mmput(bprm->mm); | |
1517 | } | |
1da177e4 LT |
1518 | |
1519 | out_file: | |
1520 | if (bprm->file) { | |
1521 | allow_write_access(bprm->file); | |
1522 | fput(bprm->file); | |
1523 | } | |
a6f76f23 | 1524 | |
498052bb | 1525 | out_unmark: |
8c652f96 ON |
1526 | if (clear_in_exec) |
1527 | current->fs->in_exec = 0; | |
f9ce1f1c | 1528 | current->in_execve = 0; |
a6f76f23 DH |
1529 | |
1530 | out_free: | |
08a6fac1 | 1531 | free_bprm(bprm); |
1da177e4 | 1532 | |
fd8328be | 1533 | out_files: |
3b125388 AV |
1534 | if (displaced) |
1535 | reset_files_struct(displaced); | |
1da177e4 LT |
1536 | out_ret: |
1537 | return retval; | |
1538 | } | |
1539 | ||
ba2d0162 ON |
1540 | int do_execve(const char *filename, |
1541 | const char __user *const __user *__argv, | |
1542 | const char __user *const __user *__envp, | |
1543 | struct pt_regs *regs) | |
1544 | { | |
0e028465 ON |
1545 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
1546 | struct user_arg_ptr envp = { .ptr.native = __envp }; | |
1547 | return do_execve_common(filename, argv, envp, regs); | |
1548 | } | |
1549 | ||
1550 | #ifdef CONFIG_COMPAT | |
1551 | int compat_do_execve(char *filename, | |
1552 | compat_uptr_t __user *__argv, | |
1553 | compat_uptr_t __user *__envp, | |
1554 | struct pt_regs *regs) | |
1555 | { | |
1556 | struct user_arg_ptr argv = { | |
1557 | .is_compat = true, | |
1558 | .ptr.compat = __argv, | |
1559 | }; | |
1560 | struct user_arg_ptr envp = { | |
1561 | .is_compat = true, | |
1562 | .ptr.compat = __envp, | |
1563 | }; | |
ba2d0162 ON |
1564 | return do_execve_common(filename, argv, envp, regs); |
1565 | } | |
0e028465 | 1566 | #endif |
ba2d0162 | 1567 | |
964ee7df | 1568 | void set_binfmt(struct linux_binfmt *new) |
1da177e4 | 1569 | { |
801460d0 HS |
1570 | struct mm_struct *mm = current->mm; |
1571 | ||
1572 | if (mm->binfmt) | |
1573 | module_put(mm->binfmt->module); | |
1da177e4 | 1574 | |
801460d0 | 1575 | mm->binfmt = new; |
964ee7df ON |
1576 | if (new) |
1577 | __module_get(new->module); | |
1da177e4 LT |
1578 | } |
1579 | ||
1580 | EXPORT_SYMBOL(set_binfmt); | |
1581 | ||
1b0d300b XF |
1582 | static int expand_corename(struct core_name *cn) |
1583 | { | |
1584 | char *old_corename = cn->corename; | |
1585 | ||
1586 | cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count); | |
1587 | cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL); | |
1588 | ||
1589 | if (!cn->corename) { | |
1590 | kfree(old_corename); | |
1591 | return -ENOMEM; | |
1592 | } | |
1593 | ||
1594 | return 0; | |
1595 | } | |
1596 | ||
1597 | static int cn_printf(struct core_name *cn, const char *fmt, ...) | |
1598 | { | |
1599 | char *cur; | |
1600 | int need; | |
1601 | int ret; | |
1602 | va_list arg; | |
1603 | ||
1604 | va_start(arg, fmt); | |
1605 | need = vsnprintf(NULL, 0, fmt, arg); | |
1606 | va_end(arg); | |
1607 | ||
1608 | if (likely(need < cn->size - cn->used - 1)) | |
1609 | goto out_printf; | |
1610 | ||
1611 | ret = expand_corename(cn); | |
1612 | if (ret) | |
1613 | goto expand_fail; | |
1614 | ||
1615 | out_printf: | |
1616 | cur = cn->corename + cn->used; | |
1617 | va_start(arg, fmt); | |
1618 | vsnprintf(cur, need + 1, fmt, arg); | |
1619 | va_end(arg); | |
1620 | cn->used += need; | |
1621 | return 0; | |
1622 | ||
1623 | expand_fail: | |
1624 | return ret; | |
1625 | } | |
1626 | ||
1da177e4 LT |
1627 | /* format_corename will inspect the pattern parameter, and output a |
1628 | * name into corename, which must have space for at least | |
1629 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
1630 | */ | |
1b0d300b | 1631 | static int format_corename(struct core_name *cn, long signr) |
1da177e4 | 1632 | { |
86a264ab | 1633 | const struct cred *cred = current_cred(); |
565b9b14 ON |
1634 | const char *pat_ptr = core_pattern; |
1635 | int ispipe = (*pat_ptr == '|'); | |
1da177e4 | 1636 | int pid_in_pattern = 0; |
1b0d300b XF |
1637 | int err = 0; |
1638 | ||
1639 | cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count); | |
1640 | cn->corename = kmalloc(cn->size, GFP_KERNEL); | |
1641 | cn->used = 0; | |
1642 | ||
1643 | if (!cn->corename) | |
1644 | return -ENOMEM; | |
1da177e4 LT |
1645 | |
1646 | /* Repeat as long as we have more pattern to process and more output | |
1647 | space */ | |
1648 | while (*pat_ptr) { | |
1649 | if (*pat_ptr != '%') { | |
1b0d300b | 1650 | if (*pat_ptr == 0) |
1da177e4 | 1651 | goto out; |
1b0d300b | 1652 | err = cn_printf(cn, "%c", *pat_ptr++); |
1da177e4 LT |
1653 | } else { |
1654 | switch (*++pat_ptr) { | |
1b0d300b | 1655 | /* single % at the end, drop that */ |
1da177e4 LT |
1656 | case 0: |
1657 | goto out; | |
1658 | /* Double percent, output one percent */ | |
1659 | case '%': | |
1b0d300b | 1660 | err = cn_printf(cn, "%c", '%'); |
1da177e4 LT |
1661 | break; |
1662 | /* pid */ | |
1663 | case 'p': | |
1664 | pid_in_pattern = 1; | |
1b0d300b XF |
1665 | err = cn_printf(cn, "%d", |
1666 | task_tgid_vnr(current)); | |
1da177e4 LT |
1667 | break; |
1668 | /* uid */ | |
1669 | case 'u': | |
1b0d300b | 1670 | err = cn_printf(cn, "%d", cred->uid); |
1da177e4 LT |
1671 | break; |
1672 | /* gid */ | |
1673 | case 'g': | |
1b0d300b | 1674 | err = cn_printf(cn, "%d", cred->gid); |
1da177e4 LT |
1675 | break; |
1676 | /* signal that caused the coredump */ | |
1677 | case 's': | |
1b0d300b | 1678 | err = cn_printf(cn, "%ld", signr); |
1da177e4 LT |
1679 | break; |
1680 | /* UNIX time of coredump */ | |
1681 | case 't': { | |
1682 | struct timeval tv; | |
1683 | do_gettimeofday(&tv); | |
1b0d300b | 1684 | err = cn_printf(cn, "%lu", tv.tv_sec); |
1da177e4 LT |
1685 | break; |
1686 | } | |
1687 | /* hostname */ | |
1688 | case 'h': | |
1689 | down_read(&uts_sem); | |
1b0d300b XF |
1690 | err = cn_printf(cn, "%s", |
1691 | utsname()->nodename); | |
1da177e4 | 1692 | up_read(&uts_sem); |
1da177e4 LT |
1693 | break; |
1694 | /* executable */ | |
1695 | case 'e': | |
1b0d300b | 1696 | err = cn_printf(cn, "%s", current->comm); |
1da177e4 | 1697 | break; |
74aadce9 NH |
1698 | /* core limit size */ |
1699 | case 'c': | |
1b0d300b XF |
1700 | err = cn_printf(cn, "%lu", |
1701 | rlimit(RLIMIT_CORE)); | |
74aadce9 | 1702 | break; |
1da177e4 LT |
1703 | default: |
1704 | break; | |
1705 | } | |
1706 | ++pat_ptr; | |
1707 | } | |
1b0d300b XF |
1708 | |
1709 | if (err) | |
1710 | return err; | |
1da177e4 | 1711 | } |
1b0d300b | 1712 | |
1da177e4 LT |
1713 | /* Backward compatibility with core_uses_pid: |
1714 | * | |
1715 | * If core_pattern does not include a %p (as is the default) | |
1716 | * and core_uses_pid is set, then .%pid will be appended to | |
c4bbafda | 1717 | * the filename. Do not do this for piped commands. */ |
6409324b | 1718 | if (!ispipe && !pid_in_pattern && core_uses_pid) { |
1b0d300b XF |
1719 | err = cn_printf(cn, ".%d", task_tgid_vnr(current)); |
1720 | if (err) | |
1721 | return err; | |
1da177e4 | 1722 | } |
c4bbafda | 1723 | out: |
c4bbafda | 1724 | return ispipe; |
1da177e4 LT |
1725 | } |
1726 | ||
5c99cbf4 | 1727 | static int zap_process(struct task_struct *start, int exit_code) |
aceecc04 ON |
1728 | { |
1729 | struct task_struct *t; | |
8cd9c249 | 1730 | int nr = 0; |
281de339 | 1731 | |
d5f70c00 | 1732 | start->signal->flags = SIGNAL_GROUP_EXIT; |
5c99cbf4 | 1733 | start->signal->group_exit_code = exit_code; |
d5f70c00 | 1734 | start->signal->group_stop_count = 0; |
aceecc04 ON |
1735 | |
1736 | t = start; | |
1737 | do { | |
39efa3ef | 1738 | task_clear_group_stop_pending(t); |
aceecc04 | 1739 | if (t != current && t->mm) { |
281de339 ON |
1740 | sigaddset(&t->pending.signal, SIGKILL); |
1741 | signal_wake_up(t, 1); | |
8cd9c249 | 1742 | nr++; |
aceecc04 | 1743 | } |
e4901f92 | 1744 | } while_each_thread(start, t); |
8cd9c249 ON |
1745 | |
1746 | return nr; | |
aceecc04 ON |
1747 | } |
1748 | ||
dcf560c5 | 1749 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
8cd9c249 | 1750 | struct core_state *core_state, int exit_code) |
1da177e4 LT |
1751 | { |
1752 | struct task_struct *g, *p; | |
5debfa6d | 1753 | unsigned long flags; |
8cd9c249 | 1754 | int nr = -EAGAIN; |
dcf560c5 ON |
1755 | |
1756 | spin_lock_irq(&tsk->sighand->siglock); | |
ed5d2cac | 1757 | if (!signal_group_exit(tsk->signal)) { |
8cd9c249 | 1758 | mm->core_state = core_state; |
5c99cbf4 | 1759 | nr = zap_process(tsk, exit_code); |
1da177e4 | 1760 | } |
dcf560c5 | 1761 | spin_unlock_irq(&tsk->sighand->siglock); |
8cd9c249 ON |
1762 | if (unlikely(nr < 0)) |
1763 | return nr; | |
1da177e4 | 1764 | |
8cd9c249 | 1765 | if (atomic_read(&mm->mm_users) == nr + 1) |
5debfa6d | 1766 | goto done; |
e4901f92 ON |
1767 | /* |
1768 | * We should find and kill all tasks which use this mm, and we should | |
999d9fc1 | 1769 | * count them correctly into ->nr_threads. We don't take tasklist |
e4901f92 ON |
1770 | * lock, but this is safe wrt: |
1771 | * | |
1772 | * fork: | |
1773 | * None of sub-threads can fork after zap_process(leader). All | |
1774 | * processes which were created before this point should be | |
1775 | * visible to zap_threads() because copy_process() adds the new | |
1776 | * process to the tail of init_task.tasks list, and lock/unlock | |
1777 | * of ->siglock provides a memory barrier. | |
1778 | * | |
1779 | * do_exit: | |
1780 | * The caller holds mm->mmap_sem. This means that the task which | |
1781 | * uses this mm can't pass exit_mm(), so it can't exit or clear | |
1782 | * its ->mm. | |
1783 | * | |
1784 | * de_thread: | |
1785 | * It does list_replace_rcu(&leader->tasks, ¤t->tasks), | |
1786 | * we must see either old or new leader, this does not matter. | |
1787 | * However, it can change p->sighand, so lock_task_sighand(p) | |
1788 | * must be used. Since p->mm != NULL and we hold ->mmap_sem | |
1789 | * it can't fail. | |
1790 | * | |
1791 | * Note also that "g" can be the old leader with ->mm == NULL | |
1792 | * and already unhashed and thus removed from ->thread_group. | |
1793 | * This is OK, __unhash_process()->list_del_rcu() does not | |
1794 | * clear the ->next pointer, we will find the new leader via | |
1795 | * next_thread(). | |
1796 | */ | |
7b1c6154 | 1797 | rcu_read_lock(); |
aceecc04 | 1798 | for_each_process(g) { |
5debfa6d ON |
1799 | if (g == tsk->group_leader) |
1800 | continue; | |
15b9f360 ON |
1801 | if (g->flags & PF_KTHREAD) |
1802 | continue; | |
aceecc04 ON |
1803 | p = g; |
1804 | do { | |
1805 | if (p->mm) { | |
15b9f360 | 1806 | if (unlikely(p->mm == mm)) { |
5debfa6d | 1807 | lock_task_sighand(p, &flags); |
5c99cbf4 | 1808 | nr += zap_process(p, exit_code); |
5debfa6d ON |
1809 | unlock_task_sighand(p, &flags); |
1810 | } | |
aceecc04 ON |
1811 | break; |
1812 | } | |
e4901f92 | 1813 | } while_each_thread(g, p); |
aceecc04 | 1814 | } |
7b1c6154 | 1815 | rcu_read_unlock(); |
5debfa6d | 1816 | done: |
c5f1cc8c | 1817 | atomic_set(&core_state->nr_threads, nr); |
8cd9c249 | 1818 | return nr; |
1da177e4 LT |
1819 | } |
1820 | ||
9d5b327b | 1821 | static int coredump_wait(int exit_code, struct core_state *core_state) |
1da177e4 | 1822 | { |
dcf560c5 ON |
1823 | struct task_struct *tsk = current; |
1824 | struct mm_struct *mm = tsk->mm; | |
dcf560c5 | 1825 | struct completion *vfork_done; |
269b005a | 1826 | int core_waiters = -EBUSY; |
1da177e4 | 1827 | |
9d5b327b | 1828 | init_completion(&core_state->startup); |
b564daf8 ON |
1829 | core_state->dumper.task = tsk; |
1830 | core_state->dumper.next = NULL; | |
269b005a ON |
1831 | |
1832 | down_write(&mm->mmap_sem); | |
1833 | if (!mm->core_state) | |
1834 | core_waiters = zap_threads(tsk, mm, core_state, exit_code); | |
2384f55f ON |
1835 | up_write(&mm->mmap_sem); |
1836 | ||
dcf560c5 ON |
1837 | if (unlikely(core_waiters < 0)) |
1838 | goto fail; | |
1839 | ||
1840 | /* | |
1841 | * Make sure nobody is waiting for us to release the VM, | |
1842 | * otherwise we can deadlock when we wait on each other | |
1843 | */ | |
1844 | vfork_done = tsk->vfork_done; | |
1845 | if (vfork_done) { | |
1846 | tsk->vfork_done = NULL; | |
1847 | complete(vfork_done); | |
1848 | } | |
1849 | ||
2384f55f | 1850 | if (core_waiters) |
9d5b327b | 1851 | wait_for_completion(&core_state->startup); |
dcf560c5 | 1852 | fail: |
dcf560c5 | 1853 | return core_waiters; |
1da177e4 LT |
1854 | } |
1855 | ||
a94e2d40 ON |
1856 | static void coredump_finish(struct mm_struct *mm) |
1857 | { | |
1858 | struct core_thread *curr, *next; | |
1859 | struct task_struct *task; | |
1860 | ||
1861 | next = mm->core_state->dumper.next; | |
1862 | while ((curr = next) != NULL) { | |
1863 | next = curr->next; | |
1864 | task = curr->task; | |
1865 | /* | |
1866 | * see exit_mm(), curr->task must not see | |
1867 | * ->task == NULL before we read ->next. | |
1868 | */ | |
1869 | smp_mb(); | |
1870 | curr->task = NULL; | |
1871 | wake_up_process(task); | |
1872 | } | |
1873 | ||
1874 | mm->core_state = NULL; | |
1875 | } | |
1876 | ||
6c5d5238 KH |
1877 | /* |
1878 | * set_dumpable converts traditional three-value dumpable to two flags and | |
1879 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but | |
1880 | * these bits are not changed atomically. So get_dumpable can observe the | |
1881 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable | |
1882 | * return either old dumpable or new one by paying attention to the order of | |
1883 | * modifying the bits. | |
1884 | * | |
1885 | * dumpable | mm->flags (binary) | |
1886 | * old new | initial interim final | |
1887 | * ---------+----------------------- | |
1888 | * 0 1 | 00 01 01 | |
1889 | * 0 2 | 00 10(*) 11 | |
1890 | * 1 0 | 01 00 00 | |
1891 | * 1 2 | 01 11 11 | |
1892 | * 2 0 | 11 10(*) 00 | |
1893 | * 2 1 | 11 11 01 | |
1894 | * | |
1895 | * (*) get_dumpable regards interim value of 10 as 11. | |
1896 | */ | |
1897 | void set_dumpable(struct mm_struct *mm, int value) | |
1898 | { | |
1899 | switch (value) { | |
1900 | case 0: | |
1901 | clear_bit(MMF_DUMPABLE, &mm->flags); | |
1902 | smp_wmb(); | |
1903 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1904 | break; | |
1905 | case 1: | |
1906 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1907 | smp_wmb(); | |
1908 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1909 | break; | |
1910 | case 2: | |
1911 | set_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1912 | smp_wmb(); | |
1913 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1914 | break; | |
1915 | } | |
1916 | } | |
6c5d5238 | 1917 | |
30736a4d | 1918 | static int __get_dumpable(unsigned long mm_flags) |
6c5d5238 KH |
1919 | { |
1920 | int ret; | |
1921 | ||
30736a4d | 1922 | ret = mm_flags & MMF_DUMPABLE_MASK; |
6c5d5238 KH |
1923 | return (ret >= 2) ? 2 : ret; |
1924 | } | |
1925 | ||
30736a4d MH |
1926 | int get_dumpable(struct mm_struct *mm) |
1927 | { | |
1928 | return __get_dumpable(mm->flags); | |
1929 | } | |
1930 | ||
61be228a NH |
1931 | static void wait_for_dump_helpers(struct file *file) |
1932 | { | |
1933 | struct pipe_inode_info *pipe; | |
1934 | ||
1935 | pipe = file->f_path.dentry->d_inode->i_pipe; | |
1936 | ||
1937 | pipe_lock(pipe); | |
1938 | pipe->readers++; | |
1939 | pipe->writers--; | |
1940 | ||
1941 | while ((pipe->readers > 1) && (!signal_pending(current))) { | |
1942 | wake_up_interruptible_sync(&pipe->wait); | |
1943 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); | |
1944 | pipe_wait(pipe); | |
1945 | } | |
1946 | ||
1947 | pipe->readers--; | |
1948 | pipe->writers++; | |
1949 | pipe_unlock(pipe); | |
1950 | ||
1951 | } | |
1952 | ||
1953 | ||
898b374a | 1954 | /* |
1bef8291 | 1955 | * umh_pipe_setup |
898b374a NH |
1956 | * helper function to customize the process used |
1957 | * to collect the core in userspace. Specifically | |
1958 | * it sets up a pipe and installs it as fd 0 (stdin) | |
1959 | * for the process. Returns 0 on success, or | |
1960 | * PTR_ERR on failure. | |
1961 | * Note that it also sets the core limit to 1. This | |
1962 | * is a special value that we use to trap recursive | |
1963 | * core dumps | |
1964 | */ | |
1965 | static int umh_pipe_setup(struct subprocess_info *info) | |
1966 | { | |
1967 | struct file *rp, *wp; | |
1968 | struct fdtable *fdt; | |
1969 | struct coredump_params *cp = (struct coredump_params *)info->data; | |
1970 | struct files_struct *cf = current->files; | |
1971 | ||
1972 | wp = create_write_pipe(0); | |
1973 | if (IS_ERR(wp)) | |
1974 | return PTR_ERR(wp); | |
1975 | ||
1976 | rp = create_read_pipe(wp, 0); | |
1977 | if (IS_ERR(rp)) { | |
1978 | free_write_pipe(wp); | |
1979 | return PTR_ERR(rp); | |
1980 | } | |
1981 | ||
1982 | cp->file = wp; | |
1983 | ||
1984 | sys_close(0); | |
1985 | fd_install(0, rp); | |
1986 | spin_lock(&cf->file_lock); | |
1987 | fdt = files_fdtable(cf); | |
1988 | FD_SET(0, fdt->open_fds); | |
1989 | FD_CLR(0, fdt->close_on_exec); | |
1990 | spin_unlock(&cf->file_lock); | |
1991 | ||
1992 | /* and disallow core files too */ | |
1993 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; | |
1994 | ||
1995 | return 0; | |
1996 | } | |
1997 | ||
8cd3ac3a | 1998 | void do_coredump(long signr, int exit_code, struct pt_regs *regs) |
1da177e4 | 1999 | { |
9d5b327b | 2000 | struct core_state core_state; |
1b0d300b | 2001 | struct core_name cn; |
1da177e4 LT |
2002 | struct mm_struct *mm = current->mm; |
2003 | struct linux_binfmt * binfmt; | |
d84f4f99 DH |
2004 | const struct cred *old_cred; |
2005 | struct cred *cred; | |
1da177e4 | 2006 | int retval = 0; |
d6e71144 | 2007 | int flag = 0; |
d5bf4c4f | 2008 | int ispipe; |
a293980c | 2009 | static atomic_t core_dump_count = ATOMIC_INIT(0); |
f6151dfe MH |
2010 | struct coredump_params cprm = { |
2011 | .signr = signr, | |
2012 | .regs = regs, | |
d554ed89 | 2013 | .limit = rlimit(RLIMIT_CORE), |
30736a4d MH |
2014 | /* |
2015 | * We must use the same mm->flags while dumping core to avoid | |
2016 | * inconsistency of bit flags, since this flag is not protected | |
2017 | * by any locks. | |
2018 | */ | |
2019 | .mm_flags = mm->flags, | |
f6151dfe | 2020 | }; |
1da177e4 | 2021 | |
0a4ff8c2 SG |
2022 | audit_core_dumps(signr); |
2023 | ||
801460d0 | 2024 | binfmt = mm->binfmt; |
1da177e4 LT |
2025 | if (!binfmt || !binfmt->core_dump) |
2026 | goto fail; | |
269b005a ON |
2027 | if (!__get_dumpable(cprm.mm_flags)) |
2028 | goto fail; | |
d84f4f99 DH |
2029 | |
2030 | cred = prepare_creds(); | |
5e43aef5 | 2031 | if (!cred) |
d84f4f99 | 2032 | goto fail; |
d6e71144 AC |
2033 | /* |
2034 | * We cannot trust fsuid as being the "true" uid of the | |
2035 | * process nor do we know its entire history. We only know it | |
2036 | * was tainted so we dump it as root in mode 2. | |
2037 | */ | |
30736a4d MH |
2038 | if (__get_dumpable(cprm.mm_flags) == 2) { |
2039 | /* Setuid core dump mode */ | |
d6e71144 | 2040 | flag = O_EXCL; /* Stop rewrite attacks */ |
d84f4f99 | 2041 | cred->fsuid = 0; /* Dump root private */ |
d6e71144 | 2042 | } |
1291cf41 | 2043 | |
9d5b327b | 2044 | retval = coredump_wait(exit_code, &core_state); |
5e43aef5 ON |
2045 | if (retval < 0) |
2046 | goto fail_creds; | |
d84f4f99 DH |
2047 | |
2048 | old_cred = override_creds(cred); | |
1da177e4 LT |
2049 | |
2050 | /* | |
2051 | * Clear any false indication of pending signals that might | |
2052 | * be seen by the filesystem code called to write the core file. | |
2053 | */ | |
1da177e4 LT |
2054 | clear_thread_flag(TIF_SIGPENDING); |
2055 | ||
1b0d300b XF |
2056 | ispipe = format_corename(&cn, signr); |
2057 | ||
2058 | if (ispipe == -ENOMEM) { | |
2059 | printk(KERN_WARNING "format_corename failed\n"); | |
2060 | printk(KERN_WARNING "Aborting core\n"); | |
2061 | goto fail_corename; | |
2062 | } | |
725eae32 | 2063 | |
c4bbafda | 2064 | if (ispipe) { |
d5bf4c4f ON |
2065 | int dump_count; |
2066 | char **helper_argv; | |
2067 | ||
898b374a | 2068 | if (cprm.limit == 1) { |
725eae32 NH |
2069 | /* |
2070 | * Normally core limits are irrelevant to pipes, since | |
2071 | * we're not writing to the file system, but we use | |
898b374a NH |
2072 | * cprm.limit of 1 here as a speacial value. Any |
2073 | * non-1 limit gets set to RLIM_INFINITY below, but | |
725eae32 NH |
2074 | * a limit of 0 skips the dump. This is a consistent |
2075 | * way to catch recursive crashes. We can still crash | |
898b374a | 2076 | * if the core_pattern binary sets RLIM_CORE = !1 |
725eae32 NH |
2077 | * but it runs as root, and can do lots of stupid things |
2078 | * Note that we use task_tgid_vnr here to grab the pid | |
2079 | * of the process group leader. That way we get the | |
2080 | * right pid if a thread in a multi-threaded | |
2081 | * core_pattern process dies. | |
2082 | */ | |
2083 | printk(KERN_WARNING | |
898b374a | 2084 | "Process %d(%s) has RLIMIT_CORE set to 1\n", |
725eae32 NH |
2085 | task_tgid_vnr(current), current->comm); |
2086 | printk(KERN_WARNING "Aborting core\n"); | |
2087 | goto fail_unlock; | |
2088 | } | |
d5bf4c4f | 2089 | cprm.limit = RLIM_INFINITY; |
725eae32 | 2090 | |
a293980c NH |
2091 | dump_count = atomic_inc_return(&core_dump_count); |
2092 | if (core_pipe_limit && (core_pipe_limit < dump_count)) { | |
2093 | printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", | |
2094 | task_tgid_vnr(current), current->comm); | |
2095 | printk(KERN_WARNING "Skipping core dump\n"); | |
2096 | goto fail_dropcount; | |
2097 | } | |
2098 | ||
1b0d300b | 2099 | helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL); |
350eaf79 TH |
2100 | if (!helper_argv) { |
2101 | printk(KERN_WARNING "%s failed to allocate memory\n", | |
2102 | __func__); | |
a293980c | 2103 | goto fail_dropcount; |
350eaf79 | 2104 | } |
32321137 | 2105 | |
d5bf4c4f ON |
2106 | retval = call_usermodehelper_fns(helper_argv[0], helper_argv, |
2107 | NULL, UMH_WAIT_EXEC, umh_pipe_setup, | |
2108 | NULL, &cprm); | |
2109 | argv_free(helper_argv); | |
2110 | if (retval) { | |
d025c9db | 2111 | printk(KERN_INFO "Core dump to %s pipe failed\n", |
1b0d300b | 2112 | cn.corename); |
d5bf4c4f | 2113 | goto close_fail; |
d025c9db | 2114 | } |
c7135411 ON |
2115 | } else { |
2116 | struct inode *inode; | |
2117 | ||
2118 | if (cprm.limit < binfmt->min_coredump) | |
2119 | goto fail_unlock; | |
2120 | ||
1b0d300b | 2121 | cprm.file = filp_open(cn.corename, |
6d4df677 AD |
2122 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
2123 | 0600); | |
c7135411 ON |
2124 | if (IS_ERR(cprm.file)) |
2125 | goto fail_unlock; | |
1da177e4 | 2126 | |
c7135411 ON |
2127 | inode = cprm.file->f_path.dentry->d_inode; |
2128 | if (inode->i_nlink > 1) | |
2129 | goto close_fail; | |
2130 | if (d_unhashed(cprm.file->f_path.dentry)) | |
2131 | goto close_fail; | |
2132 | /* | |
2133 | * AK: actually i see no reason to not allow this for named | |
2134 | * pipes etc, but keep the previous behaviour for now. | |
2135 | */ | |
2136 | if (!S_ISREG(inode->i_mode)) | |
2137 | goto close_fail; | |
2138 | /* | |
2139 | * Dont allow local users get cute and trick others to coredump | |
2140 | * into their pre-created files. | |
2141 | */ | |
2142 | if (inode->i_uid != current_fsuid()) | |
2143 | goto close_fail; | |
2144 | if (!cprm.file->f_op || !cprm.file->f_op->write) | |
2145 | goto close_fail; | |
2146 | if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file)) | |
2147 | goto close_fail; | |
2148 | } | |
1da177e4 | 2149 | |
c7135411 | 2150 | retval = binfmt->core_dump(&cprm); |
1da177e4 LT |
2151 | if (retval) |
2152 | current->signal->group_exit_code |= 0x80; | |
d5bf4c4f | 2153 | |
61be228a | 2154 | if (ispipe && core_pipe_limit) |
f6151dfe | 2155 | wait_for_dump_helpers(cprm.file); |
d5bf4c4f ON |
2156 | close_fail: |
2157 | if (cprm.file) | |
2158 | filp_close(cprm.file, NULL); | |
a293980c | 2159 | fail_dropcount: |
d5bf4c4f | 2160 | if (ispipe) |
a293980c | 2161 | atomic_dec(&core_dump_count); |
1da177e4 | 2162 | fail_unlock: |
1b0d300b XF |
2163 | kfree(cn.corename); |
2164 | fail_corename: | |
5e43aef5 | 2165 | coredump_finish(mm); |
d84f4f99 | 2166 | revert_creds(old_cred); |
5e43aef5 | 2167 | fail_creds: |
d84f4f99 | 2168 | put_cred(cred); |
1da177e4 | 2169 | fail: |
8cd3ac3a | 2170 | return; |
1da177e4 | 2171 | } |
3aa0ce82 LT |
2172 | |
2173 | /* | |
2174 | * Core dumping helper functions. These are the only things you should | |
2175 | * do on a core-file: use only these functions to write out all the | |
2176 | * necessary info. | |
2177 | */ | |
2178 | int dump_write(struct file *file, const void *addr, int nr) | |
2179 | { | |
2180 | return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr; | |
2181 | } | |
8fd01d6c | 2182 | EXPORT_SYMBOL(dump_write); |
3aa0ce82 LT |
2183 | |
2184 | int dump_seek(struct file *file, loff_t off) | |
2185 | { | |
2186 | int ret = 1; | |
2187 | ||
2188 | if (file->f_op->llseek && file->f_op->llseek != no_llseek) { | |
2189 | if (file->f_op->llseek(file, off, SEEK_CUR) < 0) | |
2190 | return 0; | |
2191 | } else { | |
2192 | char *buf = (char *)get_zeroed_page(GFP_KERNEL); | |
2193 | ||
2194 | if (!buf) | |
2195 | return 0; | |
2196 | while (off > 0) { | |
2197 | unsigned long n = off; | |
2198 | ||
2199 | if (n > PAGE_SIZE) | |
2200 | n = PAGE_SIZE; | |
2201 | if (!dump_write(file, buf, n)) { | |
2202 | ret = 0; | |
2203 | break; | |
2204 | } | |
2205 | off -= n; | |
2206 | } | |
2207 | free_page((unsigned long)buf); | |
2208 | } | |
2209 | return ret; | |
2210 | } | |
8fd01d6c | 2211 | EXPORT_SYMBOL(dump_seek); |