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> | |
1da177e4 LT |
45 | #include <linux/mount.h> |
46 | #include <linux/security.h> | |
47 | #include <linux/syscalls.h> | |
8f0ab514 | 48 | #include <linux/tsacct_kern.h> |
9f46080c | 49 | #include <linux/cn_proc.h> |
473ae30b | 50 | #include <linux/audit.h> |
6341c393 | 51 | #include <linux/tracehook.h> |
5f4123be | 52 | #include <linux/kmod.h> |
6110e3ab | 53 | #include <linux/fsnotify.h> |
5ad4e53b | 54 | #include <linux/fs_struct.h> |
61be228a | 55 | #include <linux/pipe_fs_i.h> |
3d5992d2 | 56 | #include <linux/oom.h> |
0e028465 | 57 | #include <linux/compat.h> |
1da177e4 LT |
58 | |
59 | #include <asm/uaccess.h> | |
60 | #include <asm/mmu_context.h> | |
b6a2fea3 | 61 | #include <asm/tlb.h> |
a6f76f23 | 62 | #include "internal.h" |
1da177e4 | 63 | |
1da177e4 | 64 | int core_uses_pid; |
71ce92f3 | 65 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
a293980c | 66 | unsigned int core_pipe_limit; |
d6e71144 AC |
67 | int suid_dumpable = 0; |
68 | ||
1b0d300b XF |
69 | struct core_name { |
70 | char *corename; | |
71 | int used, size; | |
72 | }; | |
73 | static atomic_t call_count = ATOMIC_INIT(1); | |
74 | ||
1da177e4 LT |
75 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
76 | ||
e4dc1b14 | 77 | static LIST_HEAD(formats); |
1da177e4 LT |
78 | static DEFINE_RWLOCK(binfmt_lock); |
79 | ||
74641f58 | 80 | int __register_binfmt(struct linux_binfmt * fmt, int insert) |
1da177e4 | 81 | { |
1da177e4 LT |
82 | if (!fmt) |
83 | return -EINVAL; | |
1da177e4 | 84 | write_lock(&binfmt_lock); |
74641f58 IK |
85 | insert ? list_add(&fmt->lh, &formats) : |
86 | list_add_tail(&fmt->lh, &formats); | |
1da177e4 LT |
87 | write_unlock(&binfmt_lock); |
88 | return 0; | |
89 | } | |
90 | ||
74641f58 | 91 | EXPORT_SYMBOL(__register_binfmt); |
1da177e4 | 92 | |
f6b450d4 | 93 | void unregister_binfmt(struct linux_binfmt * fmt) |
1da177e4 | 94 | { |
1da177e4 | 95 | write_lock(&binfmt_lock); |
e4dc1b14 | 96 | list_del(&fmt->lh); |
1da177e4 | 97 | write_unlock(&binfmt_lock); |
1da177e4 LT |
98 | } |
99 | ||
100 | EXPORT_SYMBOL(unregister_binfmt); | |
101 | ||
102 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
103 | { | |
104 | module_put(fmt->module); | |
105 | } | |
106 | ||
107 | /* | |
108 | * Note that a shared library must be both readable and executable due to | |
109 | * security reasons. | |
110 | * | |
111 | * Also note that we take the address to load from from the file itself. | |
112 | */ | |
1e7bfb21 | 113 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
1da177e4 | 114 | { |
964bd183 | 115 | struct file *file; |
964bd183 AV |
116 | char *tmp = getname(library); |
117 | int error = PTR_ERR(tmp); | |
47c805dc AV |
118 | static const struct open_flags uselib_flags = { |
119 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
120 | .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, | |
121 | .intent = LOOKUP_OPEN | |
122 | }; | |
964bd183 | 123 | |
6e8341a1 AV |
124 | if (IS_ERR(tmp)) |
125 | goto out; | |
126 | ||
47c805dc | 127 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); |
6e8341a1 AV |
128 | putname(tmp); |
129 | error = PTR_ERR(file); | |
130 | if (IS_ERR(file)) | |
1da177e4 LT |
131 | goto out; |
132 | ||
133 | error = -EINVAL; | |
6e8341a1 | 134 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
1da177e4 LT |
135 | goto exit; |
136 | ||
30524472 | 137 | error = -EACCES; |
6e8341a1 | 138 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
1da177e4 LT |
139 | goto exit; |
140 | ||
2a12a9d7 | 141 | fsnotify_open(file); |
6110e3ab | 142 | |
1da177e4 LT |
143 | error = -ENOEXEC; |
144 | if(file->f_op) { | |
145 | struct linux_binfmt * fmt; | |
146 | ||
147 | read_lock(&binfmt_lock); | |
e4dc1b14 | 148 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
149 | if (!fmt->load_shlib) |
150 | continue; | |
151 | if (!try_module_get(fmt->module)) | |
152 | continue; | |
153 | read_unlock(&binfmt_lock); | |
154 | error = fmt->load_shlib(file); | |
155 | read_lock(&binfmt_lock); | |
156 | put_binfmt(fmt); | |
157 | if (error != -ENOEXEC) | |
158 | break; | |
159 | } | |
160 | read_unlock(&binfmt_lock); | |
161 | } | |
6e8341a1 | 162 | exit: |
1da177e4 LT |
163 | fput(file); |
164 | out: | |
165 | return error; | |
1da177e4 LT |
166 | } |
167 | ||
b6a2fea3 | 168 | #ifdef CONFIG_MMU |
ae6b585e ON |
169 | /* |
170 | * The nascent bprm->mm is not visible until exec_mmap() but it can | |
171 | * use a lot of memory, account these pages in current->mm temporary | |
172 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we | |
173 | * change the counter back via acct_arg_size(0). | |
174 | */ | |
0e028465 | 175 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
176 | { |
177 | struct mm_struct *mm = current->mm; | |
178 | long diff = (long)(pages - bprm->vma_pages); | |
179 | ||
180 | if (!mm || !diff) | |
181 | return; | |
182 | ||
183 | bprm->vma_pages = pages; | |
3c77f845 | 184 | add_mm_counter(mm, MM_ANONPAGES, diff); |
3c77f845 ON |
185 | } |
186 | ||
0e028465 | 187 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
188 | int write) |
189 | { | |
190 | struct page *page; | |
191 | int ret; | |
192 | ||
193 | #ifdef CONFIG_STACK_GROWSUP | |
194 | if (write) { | |
d05f3169 | 195 | ret = expand_downwards(bprm->vma, pos); |
b6a2fea3 OW |
196 | if (ret < 0) |
197 | return NULL; | |
198 | } | |
199 | #endif | |
200 | ret = get_user_pages(current, bprm->mm, pos, | |
201 | 1, write, 1, &page, NULL); | |
202 | if (ret <= 0) | |
203 | return NULL; | |
204 | ||
205 | if (write) { | |
b6a2fea3 | 206 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
a64e715f LT |
207 | struct rlimit *rlim; |
208 | ||
3c77f845 ON |
209 | acct_arg_size(bprm, size / PAGE_SIZE); |
210 | ||
a64e715f LT |
211 | /* |
212 | * We've historically supported up to 32 pages (ARG_MAX) | |
213 | * of argument strings even with small stacks | |
214 | */ | |
215 | if (size <= ARG_MAX) | |
216 | return page; | |
b6a2fea3 OW |
217 | |
218 | /* | |
219 | * Limit to 1/4-th the stack size for the argv+env strings. | |
220 | * This ensures that: | |
221 | * - the remaining binfmt code will not run out of stack space, | |
222 | * - the program will have a reasonable amount of stack left | |
223 | * to work from. | |
224 | */ | |
a64e715f | 225 | rlim = current->signal->rlim; |
d554ed89 | 226 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
b6a2fea3 OW |
227 | put_page(page); |
228 | return NULL; | |
229 | } | |
230 | } | |
231 | ||
232 | return page; | |
233 | } | |
234 | ||
235 | static void put_arg_page(struct page *page) | |
236 | { | |
237 | put_page(page); | |
238 | } | |
239 | ||
240 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
241 | { | |
242 | } | |
243 | ||
244 | static void free_arg_pages(struct linux_binprm *bprm) | |
245 | { | |
246 | } | |
247 | ||
248 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
249 | struct page *page) | |
250 | { | |
251 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); | |
252 | } | |
253 | ||
254 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
255 | { | |
eaccbfa5 | 256 | int err; |
b6a2fea3 OW |
257 | struct vm_area_struct *vma = NULL; |
258 | struct mm_struct *mm = bprm->mm; | |
259 | ||
260 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
261 | if (!vma) | |
eaccbfa5 | 262 | return -ENOMEM; |
b6a2fea3 OW |
263 | |
264 | down_write(&mm->mmap_sem); | |
265 | vma->vm_mm = mm; | |
266 | ||
267 | /* | |
268 | * Place the stack at the largest stack address the architecture | |
269 | * supports. Later, we'll move this to an appropriate place. We don't | |
270 | * use STACK_TOP because that can depend on attributes which aren't | |
271 | * configured yet. | |
272 | */ | |
aacb3d17 | 273 | BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
b6a2fea3 OW |
274 | vma->vm_end = STACK_TOP_MAX; |
275 | vma->vm_start = vma->vm_end - PAGE_SIZE; | |
a8bef8ff | 276 | vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
3ed75eb8 | 277 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
5beb4930 | 278 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
462e635e TO |
279 | |
280 | err = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1); | |
281 | if (err) | |
282 | goto err; | |
283 | ||
b6a2fea3 | 284 | err = insert_vm_struct(mm, vma); |
eaccbfa5 | 285 | if (err) |
b6a2fea3 | 286 | goto err; |
b6a2fea3 OW |
287 | |
288 | mm->stack_vm = mm->total_vm = 1; | |
289 | up_write(&mm->mmap_sem); | |
b6a2fea3 | 290 | bprm->p = vma->vm_end - sizeof(void *); |
b6a2fea3 | 291 | return 0; |
b6a2fea3 | 292 | err: |
eaccbfa5 LFC |
293 | up_write(&mm->mmap_sem); |
294 | bprm->vma = NULL; | |
295 | kmem_cache_free(vm_area_cachep, vma); | |
b6a2fea3 OW |
296 | return err; |
297 | } | |
298 | ||
299 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
300 | { | |
301 | return len <= MAX_ARG_STRLEN; | |
302 | } | |
303 | ||
304 | #else | |
305 | ||
0e028465 | 306 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
307 | { |
308 | } | |
309 | ||
0e028465 | 310 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
311 | int write) |
312 | { | |
313 | struct page *page; | |
314 | ||
315 | page = bprm->page[pos / PAGE_SIZE]; | |
316 | if (!page && write) { | |
317 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); | |
318 | if (!page) | |
319 | return NULL; | |
320 | bprm->page[pos / PAGE_SIZE] = page; | |
321 | } | |
322 | ||
323 | return page; | |
324 | } | |
325 | ||
326 | static void put_arg_page(struct page *page) | |
327 | { | |
328 | } | |
329 | ||
330 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
331 | { | |
332 | if (bprm->page[i]) { | |
333 | __free_page(bprm->page[i]); | |
334 | bprm->page[i] = NULL; | |
335 | } | |
336 | } | |
337 | ||
338 | static void free_arg_pages(struct linux_binprm *bprm) | |
339 | { | |
340 | int i; | |
341 | ||
342 | for (i = 0; i < MAX_ARG_PAGES; i++) | |
343 | free_arg_page(bprm, i); | |
344 | } | |
345 | ||
346 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
347 | struct page *page) | |
348 | { | |
349 | } | |
350 | ||
351 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
352 | { | |
353 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); | |
354 | return 0; | |
355 | } | |
356 | ||
357 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
358 | { | |
359 | return len <= bprm->p; | |
360 | } | |
361 | ||
362 | #endif /* CONFIG_MMU */ | |
363 | ||
364 | /* | |
365 | * Create a new mm_struct and populate it with a temporary stack | |
366 | * vm_area_struct. We don't have enough context at this point to set the stack | |
367 | * flags, permissions, and offset, so we use temporary values. We'll update | |
368 | * them later in setup_arg_pages(). | |
369 | */ | |
370 | int bprm_mm_init(struct linux_binprm *bprm) | |
371 | { | |
372 | int err; | |
373 | struct mm_struct *mm = NULL; | |
374 | ||
375 | bprm->mm = mm = mm_alloc(); | |
376 | err = -ENOMEM; | |
377 | if (!mm) | |
378 | goto err; | |
379 | ||
380 | err = init_new_context(current, mm); | |
381 | if (err) | |
382 | goto err; | |
383 | ||
384 | err = __bprm_mm_init(bprm); | |
385 | if (err) | |
386 | goto err; | |
387 | ||
388 | return 0; | |
389 | ||
390 | err: | |
391 | if (mm) { | |
392 | bprm->mm = NULL; | |
393 | mmdrop(mm); | |
394 | } | |
395 | ||
396 | return err; | |
397 | } | |
398 | ||
ba2d0162 | 399 | struct user_arg_ptr { |
0e028465 ON |
400 | #ifdef CONFIG_COMPAT |
401 | bool is_compat; | |
402 | #endif | |
403 | union { | |
404 | const char __user *const __user *native; | |
405 | #ifdef CONFIG_COMPAT | |
406 | compat_uptr_t __user *compat; | |
407 | #endif | |
408 | } ptr; | |
ba2d0162 ON |
409 | }; |
410 | ||
411 | static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) | |
1d1dbf81 | 412 | { |
0e028465 ON |
413 | const char __user *native; |
414 | ||
415 | #ifdef CONFIG_COMPAT | |
416 | if (unlikely(argv.is_compat)) { | |
417 | compat_uptr_t compat; | |
418 | ||
419 | if (get_user(compat, argv.ptr.compat + nr)) | |
420 | return ERR_PTR(-EFAULT); | |
1d1dbf81 | 421 | |
0e028465 ON |
422 | return compat_ptr(compat); |
423 | } | |
424 | #endif | |
425 | ||
426 | if (get_user(native, argv.ptr.native + nr)) | |
1d1dbf81 ON |
427 | return ERR_PTR(-EFAULT); |
428 | ||
0e028465 | 429 | return native; |
1d1dbf81 ON |
430 | } |
431 | ||
1da177e4 LT |
432 | /* |
433 | * count() counts the number of strings in array ARGV. | |
434 | */ | |
ba2d0162 | 435 | static int count(struct user_arg_ptr argv, int max) |
1da177e4 LT |
436 | { |
437 | int i = 0; | |
438 | ||
0e028465 | 439 | if (argv.ptr.native != NULL) { |
1da177e4 | 440 | for (;;) { |
1d1dbf81 | 441 | const char __user *p = get_user_arg_ptr(argv, i); |
1da177e4 | 442 | |
1da177e4 LT |
443 | if (!p) |
444 | break; | |
1d1dbf81 ON |
445 | |
446 | if (IS_ERR(p)) | |
447 | return -EFAULT; | |
448 | ||
362e6663 | 449 | if (i++ >= max) |
1da177e4 | 450 | return -E2BIG; |
9aea5a65 RM |
451 | |
452 | if (fatal_signal_pending(current)) | |
453 | return -ERESTARTNOHAND; | |
1da177e4 LT |
454 | cond_resched(); |
455 | } | |
456 | } | |
457 | return i; | |
458 | } | |
459 | ||
460 | /* | |
b6a2fea3 OW |
461 | * 'copy_strings()' copies argument/environment strings from the old |
462 | * processes's memory to the new process's stack. The call to get_user_pages() | |
463 | * ensures the destination page is created and not swapped out. | |
1da177e4 | 464 | */ |
ba2d0162 | 465 | static int copy_strings(int argc, struct user_arg_ptr argv, |
75c96f85 | 466 | struct linux_binprm *bprm) |
1da177e4 LT |
467 | { |
468 | struct page *kmapped_page = NULL; | |
469 | char *kaddr = NULL; | |
b6a2fea3 | 470 | unsigned long kpos = 0; |
1da177e4 LT |
471 | int ret; |
472 | ||
473 | while (argc-- > 0) { | |
d7627467 | 474 | const char __user *str; |
1da177e4 LT |
475 | int len; |
476 | unsigned long pos; | |
477 | ||
1d1dbf81 ON |
478 | ret = -EFAULT; |
479 | str = get_user_arg_ptr(argv, argc); | |
480 | if (IS_ERR(str)) | |
1da177e4 | 481 | goto out; |
1da177e4 | 482 | |
1d1dbf81 ON |
483 | len = strnlen_user(str, MAX_ARG_STRLEN); |
484 | if (!len) | |
485 | goto out; | |
486 | ||
487 | ret = -E2BIG; | |
488 | if (!valid_arg_len(bprm, len)) | |
1da177e4 | 489 | goto out; |
1da177e4 | 490 | |
b6a2fea3 | 491 | /* We're going to work our way backwords. */ |
1da177e4 | 492 | pos = bprm->p; |
b6a2fea3 OW |
493 | str += len; |
494 | bprm->p -= len; | |
1da177e4 LT |
495 | |
496 | while (len > 0) { | |
1da177e4 | 497 | int offset, bytes_to_copy; |
1da177e4 | 498 | |
9aea5a65 RM |
499 | if (fatal_signal_pending(current)) { |
500 | ret = -ERESTARTNOHAND; | |
501 | goto out; | |
502 | } | |
7993bc1f RM |
503 | cond_resched(); |
504 | ||
1da177e4 | 505 | offset = pos % PAGE_SIZE; |
b6a2fea3 OW |
506 | if (offset == 0) |
507 | offset = PAGE_SIZE; | |
508 | ||
509 | bytes_to_copy = offset; | |
510 | if (bytes_to_copy > len) | |
511 | bytes_to_copy = len; | |
512 | ||
513 | offset -= bytes_to_copy; | |
514 | pos -= bytes_to_copy; | |
515 | str -= bytes_to_copy; | |
516 | len -= bytes_to_copy; | |
517 | ||
518 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { | |
519 | struct page *page; | |
520 | ||
521 | page = get_arg_page(bprm, pos, 1); | |
1da177e4 | 522 | if (!page) { |
b6a2fea3 | 523 | ret = -E2BIG; |
1da177e4 LT |
524 | goto out; |
525 | } | |
1da177e4 | 526 | |
b6a2fea3 OW |
527 | if (kmapped_page) { |
528 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 529 | kunmap(kmapped_page); |
b6a2fea3 OW |
530 | put_arg_page(kmapped_page); |
531 | } | |
1da177e4 LT |
532 | kmapped_page = page; |
533 | kaddr = kmap(kmapped_page); | |
b6a2fea3 OW |
534 | kpos = pos & PAGE_MASK; |
535 | flush_arg_page(bprm, kpos, kmapped_page); | |
1da177e4 | 536 | } |
b6a2fea3 | 537 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
1da177e4 LT |
538 | ret = -EFAULT; |
539 | goto out; | |
540 | } | |
1da177e4 LT |
541 | } |
542 | } | |
543 | ret = 0; | |
544 | out: | |
b6a2fea3 OW |
545 | if (kmapped_page) { |
546 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 547 | kunmap(kmapped_page); |
b6a2fea3 OW |
548 | put_arg_page(kmapped_page); |
549 | } | |
1da177e4 LT |
550 | return ret; |
551 | } | |
552 | ||
553 | /* | |
554 | * Like copy_strings, but get argv and its values from kernel memory. | |
555 | */ | |
ba2d0162 | 556 | int copy_strings_kernel(int argc, const char *const *__argv, |
d7627467 | 557 | struct linux_binprm *bprm) |
1da177e4 LT |
558 | { |
559 | int r; | |
560 | mm_segment_t oldfs = get_fs(); | |
ba2d0162 | 561 | struct user_arg_ptr argv = { |
0e028465 | 562 | .ptr.native = (const char __user *const __user *)__argv, |
ba2d0162 ON |
563 | }; |
564 | ||
1da177e4 | 565 | set_fs(KERNEL_DS); |
ba2d0162 | 566 | r = copy_strings(argc, argv, bprm); |
1da177e4 | 567 | set_fs(oldfs); |
ba2d0162 | 568 | |
1da177e4 LT |
569 | return r; |
570 | } | |
1da177e4 LT |
571 | EXPORT_SYMBOL(copy_strings_kernel); |
572 | ||
573 | #ifdef CONFIG_MMU | |
b6a2fea3 | 574 | |
1da177e4 | 575 | /* |
b6a2fea3 OW |
576 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
577 | * the binfmt code determines where the new stack should reside, we shift it to | |
578 | * its final location. The process proceeds as follows: | |
1da177e4 | 579 | * |
b6a2fea3 OW |
580 | * 1) Use shift to calculate the new vma endpoints. |
581 | * 2) Extend vma to cover both the old and new ranges. This ensures the | |
582 | * arguments passed to subsequent functions are consistent. | |
583 | * 3) Move vma's page tables to the new range. | |
584 | * 4) Free up any cleared pgd range. | |
585 | * 5) Shrink the vma to cover only the new range. | |
1da177e4 | 586 | */ |
b6a2fea3 | 587 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
1da177e4 LT |
588 | { |
589 | struct mm_struct *mm = vma->vm_mm; | |
b6a2fea3 OW |
590 | unsigned long old_start = vma->vm_start; |
591 | unsigned long old_end = vma->vm_end; | |
592 | unsigned long length = old_end - old_start; | |
593 | unsigned long new_start = old_start - shift; | |
594 | unsigned long new_end = old_end - shift; | |
d16dfc55 | 595 | struct mmu_gather tlb; |
1da177e4 | 596 | |
b6a2fea3 | 597 | BUG_ON(new_start > new_end); |
1da177e4 | 598 | |
b6a2fea3 OW |
599 | /* |
600 | * ensure there are no vmas between where we want to go | |
601 | * and where we are | |
602 | */ | |
603 | if (vma != find_vma(mm, new_start)) | |
604 | return -EFAULT; | |
605 | ||
606 | /* | |
607 | * cover the whole range: [new_start, old_end) | |
608 | */ | |
5beb4930 RR |
609 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
610 | return -ENOMEM; | |
b6a2fea3 OW |
611 | |
612 | /* | |
613 | * move the page tables downwards, on failure we rely on | |
614 | * process cleanup to remove whatever mess we made. | |
615 | */ | |
616 | if (length != move_page_tables(vma, old_start, | |
617 | vma, new_start, length)) | |
618 | return -ENOMEM; | |
619 | ||
620 | lru_add_drain(); | |
d16dfc55 | 621 | tlb_gather_mmu(&tlb, mm, 0); |
b6a2fea3 OW |
622 | if (new_end > old_start) { |
623 | /* | |
624 | * when the old and new regions overlap clear from new_end. | |
625 | */ | |
d16dfc55 | 626 | free_pgd_range(&tlb, new_end, old_end, new_end, |
b6a2fea3 OW |
627 | vma->vm_next ? vma->vm_next->vm_start : 0); |
628 | } else { | |
629 | /* | |
630 | * otherwise, clean from old_start; this is done to not touch | |
631 | * the address space in [new_end, old_start) some architectures | |
632 | * have constraints on va-space that make this illegal (IA64) - | |
633 | * for the others its just a little faster. | |
634 | */ | |
d16dfc55 | 635 | free_pgd_range(&tlb, old_start, old_end, new_end, |
b6a2fea3 | 636 | vma->vm_next ? vma->vm_next->vm_start : 0); |
1da177e4 | 637 | } |
d16dfc55 | 638 | tlb_finish_mmu(&tlb, new_end, old_end); |
b6a2fea3 OW |
639 | |
640 | /* | |
5beb4930 | 641 | * Shrink the vma to just the new range. Always succeeds. |
b6a2fea3 OW |
642 | */ |
643 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); | |
644 | ||
645 | return 0; | |
1da177e4 LT |
646 | } |
647 | ||
b6a2fea3 OW |
648 | /* |
649 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, | |
650 | * the stack is optionally relocated, and some extra space is added. | |
651 | */ | |
1da177e4 LT |
652 | int setup_arg_pages(struct linux_binprm *bprm, |
653 | unsigned long stack_top, | |
654 | int executable_stack) | |
655 | { | |
b6a2fea3 OW |
656 | unsigned long ret; |
657 | unsigned long stack_shift; | |
1da177e4 | 658 | struct mm_struct *mm = current->mm; |
b6a2fea3 OW |
659 | struct vm_area_struct *vma = bprm->vma; |
660 | struct vm_area_struct *prev = NULL; | |
661 | unsigned long vm_flags; | |
662 | unsigned long stack_base; | |
803bf5ec MN |
663 | unsigned long stack_size; |
664 | unsigned long stack_expand; | |
665 | unsigned long rlim_stack; | |
1da177e4 LT |
666 | |
667 | #ifdef CONFIG_STACK_GROWSUP | |
1da177e4 | 668 | /* Limit stack size to 1GB */ |
d554ed89 | 669 | stack_base = rlimit_max(RLIMIT_STACK); |
1da177e4 LT |
670 | if (stack_base > (1 << 30)) |
671 | stack_base = 1 << 30; | |
1da177e4 | 672 | |
b6a2fea3 OW |
673 | /* Make sure we didn't let the argument array grow too large. */ |
674 | if (vma->vm_end - vma->vm_start > stack_base) | |
675 | return -ENOMEM; | |
1da177e4 | 676 | |
b6a2fea3 | 677 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
1da177e4 | 678 | |
b6a2fea3 OW |
679 | stack_shift = vma->vm_start - stack_base; |
680 | mm->arg_start = bprm->p - stack_shift; | |
681 | bprm->p = vma->vm_end - stack_shift; | |
1da177e4 | 682 | #else |
b6a2fea3 OW |
683 | stack_top = arch_align_stack(stack_top); |
684 | stack_top = PAGE_ALIGN(stack_top); | |
1b528181 RM |
685 | |
686 | if (unlikely(stack_top < mmap_min_addr) || | |
687 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) | |
688 | return -ENOMEM; | |
689 | ||
b6a2fea3 OW |
690 | stack_shift = vma->vm_end - stack_top; |
691 | ||
692 | bprm->p -= stack_shift; | |
1da177e4 | 693 | mm->arg_start = bprm->p; |
1da177e4 LT |
694 | #endif |
695 | ||
1da177e4 | 696 | if (bprm->loader) |
b6a2fea3 OW |
697 | bprm->loader -= stack_shift; |
698 | bprm->exec -= stack_shift; | |
1da177e4 | 699 | |
1da177e4 | 700 | down_write(&mm->mmap_sem); |
96a8e13e | 701 | vm_flags = VM_STACK_FLAGS; |
b6a2fea3 OW |
702 | |
703 | /* | |
704 | * Adjust stack execute permissions; explicitly enable for | |
705 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone | |
706 | * (arch default) otherwise. | |
707 | */ | |
708 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
709 | vm_flags |= VM_EXEC; | |
710 | else if (executable_stack == EXSTACK_DISABLE_X) | |
711 | vm_flags &= ~VM_EXEC; | |
712 | vm_flags |= mm->def_flags; | |
a8bef8ff | 713 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
b6a2fea3 OW |
714 | |
715 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, | |
716 | vm_flags); | |
717 | if (ret) | |
718 | goto out_unlock; | |
719 | BUG_ON(prev != vma); | |
720 | ||
721 | /* Move stack pages down in memory. */ | |
722 | if (stack_shift) { | |
723 | ret = shift_arg_pages(vma, stack_shift); | |
fc63cf23 AB |
724 | if (ret) |
725 | goto out_unlock; | |
1da177e4 LT |
726 | } |
727 | ||
a8bef8ff MG |
728 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
729 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; | |
730 | ||
5ef097dd | 731 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
803bf5ec MN |
732 | stack_size = vma->vm_end - vma->vm_start; |
733 | /* | |
734 | * Align this down to a page boundary as expand_stack | |
735 | * will align it up. | |
736 | */ | |
737 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; | |
b6a2fea3 | 738 | #ifdef CONFIG_STACK_GROWSUP |
803bf5ec MN |
739 | if (stack_size + stack_expand > rlim_stack) |
740 | stack_base = vma->vm_start + rlim_stack; | |
741 | else | |
742 | stack_base = vma->vm_end + stack_expand; | |
b6a2fea3 | 743 | #else |
803bf5ec MN |
744 | if (stack_size + stack_expand > rlim_stack) |
745 | stack_base = vma->vm_end - rlim_stack; | |
746 | else | |
747 | stack_base = vma->vm_start - stack_expand; | |
b6a2fea3 | 748 | #endif |
3af9e859 | 749 | current->mm->start_stack = bprm->p; |
b6a2fea3 OW |
750 | ret = expand_stack(vma, stack_base); |
751 | if (ret) | |
752 | ret = -EFAULT; | |
753 | ||
754 | out_unlock: | |
1da177e4 | 755 | up_write(&mm->mmap_sem); |
fc63cf23 | 756 | return ret; |
1da177e4 | 757 | } |
1da177e4 LT |
758 | EXPORT_SYMBOL(setup_arg_pages); |
759 | ||
1da177e4 LT |
760 | #endif /* CONFIG_MMU */ |
761 | ||
762 | struct file *open_exec(const char *name) | |
763 | { | |
1da177e4 | 764 | struct file *file; |
e56b6a5d | 765 | int err; |
47c805dc AV |
766 | static const struct open_flags open_exec_flags = { |
767 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
768 | .acc_mode = MAY_EXEC | MAY_OPEN, | |
769 | .intent = LOOKUP_OPEN | |
770 | }; | |
1da177e4 | 771 | |
47c805dc | 772 | file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); |
6e8341a1 | 773 | if (IS_ERR(file)) |
e56b6a5d CH |
774 | goto out; |
775 | ||
776 | err = -EACCES; | |
6e8341a1 AV |
777 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
778 | goto exit; | |
e56b6a5d | 779 | |
6e8341a1 AV |
780 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
781 | goto exit; | |
e56b6a5d | 782 | |
2a12a9d7 | 783 | fsnotify_open(file); |
6110e3ab | 784 | |
e56b6a5d | 785 | err = deny_write_access(file); |
6e8341a1 AV |
786 | if (err) |
787 | goto exit; | |
1da177e4 | 788 | |
6e8341a1 | 789 | out: |
e56b6a5d CH |
790 | return file; |
791 | ||
6e8341a1 AV |
792 | exit: |
793 | fput(file); | |
e56b6a5d CH |
794 | return ERR_PTR(err); |
795 | } | |
1da177e4 LT |
796 | EXPORT_SYMBOL(open_exec); |
797 | ||
6777d773 MZ |
798 | int kernel_read(struct file *file, loff_t offset, |
799 | char *addr, unsigned long count) | |
1da177e4 LT |
800 | { |
801 | mm_segment_t old_fs; | |
802 | loff_t pos = offset; | |
803 | int result; | |
804 | ||
805 | old_fs = get_fs(); | |
806 | set_fs(get_ds()); | |
807 | /* The cast to a user pointer is valid due to the set_fs() */ | |
808 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
809 | set_fs(old_fs); | |
810 | return result; | |
811 | } | |
812 | ||
813 | EXPORT_SYMBOL(kernel_read); | |
814 | ||
815 | static int exec_mmap(struct mm_struct *mm) | |
816 | { | |
817 | struct task_struct *tsk; | |
818 | struct mm_struct * old_mm, *active_mm; | |
819 | ||
820 | /* Notify parent that we're no longer interested in the old VM */ | |
821 | tsk = current; | |
822 | old_mm = current->mm; | |
34e55232 | 823 | sync_mm_rss(tsk, old_mm); |
1da177e4 LT |
824 | mm_release(tsk, old_mm); |
825 | ||
826 | if (old_mm) { | |
827 | /* | |
828 | * Make sure that if there is a core dump in progress | |
829 | * for the old mm, we get out and die instead of going | |
830 | * through with the exec. We must hold mmap_sem around | |
999d9fc1 | 831 | * checking core_state and changing tsk->mm. |
1da177e4 LT |
832 | */ |
833 | down_read(&old_mm->mmap_sem); | |
999d9fc1 | 834 | if (unlikely(old_mm->core_state)) { |
1da177e4 LT |
835 | up_read(&old_mm->mmap_sem); |
836 | return -EINTR; | |
837 | } | |
838 | } | |
839 | task_lock(tsk); | |
840 | active_mm = tsk->active_mm; | |
841 | tsk->mm = mm; | |
842 | tsk->active_mm = mm; | |
843 | activate_mm(active_mm, mm); | |
3d5992d2 YH |
844 | if (old_mm && tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { |
845 | atomic_dec(&old_mm->oom_disable_count); | |
846 | atomic_inc(&tsk->mm->oom_disable_count); | |
847 | } | |
1da177e4 LT |
848 | task_unlock(tsk); |
849 | arch_pick_mmap_layout(mm); | |
850 | if (old_mm) { | |
851 | up_read(&old_mm->mmap_sem); | |
7dddb12c | 852 | BUG_ON(active_mm != old_mm); |
31a78f23 | 853 | mm_update_next_owner(old_mm); |
1da177e4 LT |
854 | mmput(old_mm); |
855 | return 0; | |
856 | } | |
857 | mmdrop(active_mm); | |
858 | return 0; | |
859 | } | |
860 | ||
861 | /* | |
862 | * This function makes sure the current process has its own signal table, | |
863 | * so that flush_signal_handlers can later reset the handlers without | |
864 | * disturbing other processes. (Other processes might share the signal | |
865 | * table via the CLONE_SIGHAND option to clone().) | |
866 | */ | |
858119e1 | 867 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
868 | { |
869 | struct signal_struct *sig = tsk->signal; | |
b2c903b8 | 870 | struct sighand_struct *oldsighand = tsk->sighand; |
1da177e4 | 871 | spinlock_t *lock = &oldsighand->siglock; |
1da177e4 | 872 | |
aafe6c2a | 873 | if (thread_group_empty(tsk)) |
1da177e4 LT |
874 | goto no_thread_group; |
875 | ||
876 | /* | |
877 | * Kill all other threads in the thread group. | |
1da177e4 | 878 | */ |
1da177e4 | 879 | spin_lock_irq(lock); |
ed5d2cac | 880 | if (signal_group_exit(sig)) { |
1da177e4 LT |
881 | /* |
882 | * Another group action in progress, just | |
883 | * return so that the signal is processed. | |
884 | */ | |
885 | spin_unlock_irq(lock); | |
1da177e4 LT |
886 | return -EAGAIN; |
887 | } | |
d344193a | 888 | |
ed5d2cac | 889 | sig->group_exit_task = tsk; |
d344193a ON |
890 | sig->notify_count = zap_other_threads(tsk); |
891 | if (!thread_group_leader(tsk)) | |
892 | sig->notify_count--; | |
1da177e4 | 893 | |
d344193a | 894 | while (sig->notify_count) { |
1da177e4 LT |
895 | __set_current_state(TASK_UNINTERRUPTIBLE); |
896 | spin_unlock_irq(lock); | |
897 | schedule(); | |
898 | spin_lock_irq(lock); | |
899 | } | |
1da177e4 LT |
900 | spin_unlock_irq(lock); |
901 | ||
902 | /* | |
903 | * At this point all other threads have exited, all we have to | |
904 | * do is to wait for the thread group leader to become inactive, | |
905 | * and to assume its PID: | |
906 | */ | |
aafe6c2a | 907 | if (!thread_group_leader(tsk)) { |
8187926b | 908 | struct task_struct *leader = tsk->group_leader; |
6db840fa | 909 | |
2800d8d1 | 910 | sig->notify_count = -1; /* for exit_notify() */ |
6db840fa ON |
911 | for (;;) { |
912 | write_lock_irq(&tasklist_lock); | |
913 | if (likely(leader->exit_state)) | |
914 | break; | |
915 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
916 | write_unlock_irq(&tasklist_lock); | |
917 | schedule(); | |
918 | } | |
1da177e4 | 919 | |
f5e90281 RM |
920 | /* |
921 | * The only record we have of the real-time age of a | |
922 | * process, regardless of execs it's done, is start_time. | |
923 | * All the past CPU time is accumulated in signal_struct | |
924 | * from sister threads now dead. But in this non-leader | |
925 | * exec, nothing survives from the original leader thread, | |
926 | * whose birth marks the true age of this process now. | |
927 | * When we take on its identity by switching to its PID, we | |
928 | * also take its birthdate (always earlier than our own). | |
929 | */ | |
aafe6c2a | 930 | tsk->start_time = leader->start_time; |
f5e90281 | 931 | |
bac0abd6 PE |
932 | BUG_ON(!same_thread_group(leader, tsk)); |
933 | BUG_ON(has_group_leader_pid(tsk)); | |
1da177e4 LT |
934 | /* |
935 | * An exec() starts a new thread group with the | |
936 | * TGID of the previous thread group. Rehash the | |
937 | * two threads with a switched PID, and release | |
938 | * the former thread group leader: | |
939 | */ | |
d73d6529 EB |
940 | |
941 | /* Become a process group leader with the old leader's pid. | |
c18258c6 EB |
942 | * The old leader becomes a thread of the this thread group. |
943 | * Note: The old leader also uses this pid until release_task | |
d73d6529 EB |
944 | * is called. Odd but simple and correct. |
945 | */ | |
aafe6c2a EB |
946 | detach_pid(tsk, PIDTYPE_PID); |
947 | tsk->pid = leader->pid; | |
3743ca05 | 948 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
aafe6c2a EB |
949 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
950 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
9cd80bbb | 951 | |
aafe6c2a | 952 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
9cd80bbb | 953 | list_replace_init(&leader->sibling, &tsk->sibling); |
1da177e4 | 954 | |
aafe6c2a EB |
955 | tsk->group_leader = tsk; |
956 | leader->group_leader = tsk; | |
de12a787 | 957 | |
aafe6c2a | 958 | tsk->exit_signal = SIGCHLD; |
087806b1 | 959 | leader->exit_signal = -1; |
962b564c ON |
960 | |
961 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
962 | leader->exit_state = EXIT_DEAD; | |
eac1b5e5 ON |
963 | |
964 | /* | |
965 | * We are going to release_task()->ptrace_unlink() silently, | |
966 | * the tracer can sleep in do_wait(). EXIT_DEAD guarantees | |
967 | * the tracer wont't block again waiting for this thread. | |
968 | */ | |
969 | if (unlikely(leader->ptrace)) | |
970 | __wake_up_parent(leader, leader->parent); | |
1da177e4 | 971 | write_unlock_irq(&tasklist_lock); |
8187926b ON |
972 | |
973 | release_task(leader); | |
ed5d2cac | 974 | } |
1da177e4 | 975 | |
6db840fa ON |
976 | sig->group_exit_task = NULL; |
977 | sig->notify_count = 0; | |
1da177e4 LT |
978 | |
979 | no_thread_group: | |
1f10206c JP |
980 | if (current->mm) |
981 | setmax_mm_hiwater_rss(&sig->maxrss, current->mm); | |
982 | ||
1da177e4 | 983 | exit_itimers(sig); |
cbaffba1 | 984 | flush_itimer_signals(); |
329f7dba | 985 | |
b2c903b8 ON |
986 | if (atomic_read(&oldsighand->count) != 1) { |
987 | struct sighand_struct *newsighand; | |
1da177e4 | 988 | /* |
b2c903b8 ON |
989 | * This ->sighand is shared with the CLONE_SIGHAND |
990 | * but not CLONE_THREAD task, switch to the new one. | |
1da177e4 | 991 | */ |
b2c903b8 ON |
992 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
993 | if (!newsighand) | |
994 | return -ENOMEM; | |
995 | ||
1da177e4 LT |
996 | atomic_set(&newsighand->count, 1); |
997 | memcpy(newsighand->action, oldsighand->action, | |
998 | sizeof(newsighand->action)); | |
999 | ||
1000 | write_lock_irq(&tasklist_lock); | |
1001 | spin_lock(&oldsighand->siglock); | |
aafe6c2a | 1002 | rcu_assign_pointer(tsk->sighand, newsighand); |
1da177e4 LT |
1003 | spin_unlock(&oldsighand->siglock); |
1004 | write_unlock_irq(&tasklist_lock); | |
1005 | ||
fba2afaa | 1006 | __cleanup_sighand(oldsighand); |
1da177e4 LT |
1007 | } |
1008 | ||
aafe6c2a | 1009 | BUG_ON(!thread_group_leader(tsk)); |
1da177e4 LT |
1010 | return 0; |
1011 | } | |
0840a90d | 1012 | |
1da177e4 LT |
1013 | /* |
1014 | * These functions flushes out all traces of the currently running executable | |
1015 | * so that a new one can be started | |
1016 | */ | |
858119e1 | 1017 | static void flush_old_files(struct files_struct * files) |
1da177e4 LT |
1018 | { |
1019 | long j = -1; | |
badf1662 | 1020 | struct fdtable *fdt; |
1da177e4 LT |
1021 | |
1022 | spin_lock(&files->file_lock); | |
1023 | for (;;) { | |
1024 | unsigned long set, i; | |
1025 | ||
1026 | j++; | |
1027 | i = j * __NFDBITS; | |
badf1662 | 1028 | fdt = files_fdtable(files); |
bbea9f69 | 1029 | if (i >= fdt->max_fds) |
1da177e4 | 1030 | break; |
badf1662 | 1031 | set = fdt->close_on_exec->fds_bits[j]; |
1da177e4 LT |
1032 | if (!set) |
1033 | continue; | |
badf1662 | 1034 | fdt->close_on_exec->fds_bits[j] = 0; |
1da177e4 LT |
1035 | spin_unlock(&files->file_lock); |
1036 | for ( ; set ; i++,set >>= 1) { | |
1037 | if (set & 1) { | |
1038 | sys_close(i); | |
1039 | } | |
1040 | } | |
1041 | spin_lock(&files->file_lock); | |
1042 | ||
1043 | } | |
1044 | spin_unlock(&files->file_lock); | |
1045 | } | |
1046 | ||
59714d65 | 1047 | char *get_task_comm(char *buf, struct task_struct *tsk) |
1da177e4 LT |
1048 | { |
1049 | /* buf must be at least sizeof(tsk->comm) in size */ | |
1050 | task_lock(tsk); | |
1051 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
1052 | task_unlock(tsk); | |
59714d65 | 1053 | return buf; |
1da177e4 | 1054 | } |
7d74f492 | 1055 | EXPORT_SYMBOL_GPL(get_task_comm); |
1da177e4 LT |
1056 | |
1057 | void set_task_comm(struct task_struct *tsk, char *buf) | |
1058 | { | |
1059 | task_lock(tsk); | |
4614a696 JS |
1060 | |
1061 | /* | |
1062 | * Threads may access current->comm without holding | |
1063 | * the task lock, so write the string carefully. | |
1064 | * Readers without a lock may see incomplete new | |
1065 | * names but are safe from non-terminating string reads. | |
1066 | */ | |
1067 | memset(tsk->comm, 0, TASK_COMM_LEN); | |
1068 | wmb(); | |
1da177e4 LT |
1069 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
1070 | task_unlock(tsk); | |
cdd6c482 | 1071 | perf_event_comm(tsk); |
1da177e4 LT |
1072 | } |
1073 | ||
1074 | int flush_old_exec(struct linux_binprm * bprm) | |
1075 | { | |
221af7f8 | 1076 | int retval; |
1da177e4 LT |
1077 | |
1078 | /* | |
1079 | * Make sure we have a private signal table and that | |
1080 | * we are unassociated from the previous thread group. | |
1081 | */ | |
1082 | retval = de_thread(current); | |
1083 | if (retval) | |
1084 | goto out; | |
1085 | ||
925d1c40 MH |
1086 | set_mm_exe_file(bprm->mm, bprm->file); |
1087 | ||
1da177e4 LT |
1088 | /* |
1089 | * Release all of the old mmap stuff | |
1090 | */ | |
3c77f845 | 1091 | acct_arg_size(bprm, 0); |
1da177e4 LT |
1092 | retval = exec_mmap(bprm->mm); |
1093 | if (retval) | |
fd8328be | 1094 | goto out; |
1da177e4 LT |
1095 | |
1096 | bprm->mm = NULL; /* We're using it now */ | |
7ab02af4 | 1097 | |
dac853ae | 1098 | set_fs(USER_DS); |
98391cf4 | 1099 | current->flags &= ~(PF_RANDOMIZE | PF_KTHREAD); |
7ab02af4 LT |
1100 | flush_thread(); |
1101 | current->personality &= ~bprm->per_clear; | |
1102 | ||
221af7f8 LT |
1103 | return 0; |
1104 | ||
1105 | out: | |
1106 | return retval; | |
1107 | } | |
1108 | EXPORT_SYMBOL(flush_old_exec); | |
1109 | ||
1b5d783c AV |
1110 | void would_dump(struct linux_binprm *bprm, struct file *file) |
1111 | { | |
1112 | if (inode_permission(file->f_path.dentry->d_inode, MAY_READ) < 0) | |
1113 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; | |
1114 | } | |
1115 | EXPORT_SYMBOL(would_dump); | |
1116 | ||
221af7f8 LT |
1117 | void setup_new_exec(struct linux_binprm * bprm) |
1118 | { | |
1119 | int i, ch; | |
d7627467 | 1120 | const char *name; |
221af7f8 LT |
1121 | char tcomm[sizeof(current->comm)]; |
1122 | ||
1123 | arch_pick_mmap_layout(current->mm); | |
1da177e4 LT |
1124 | |
1125 | /* This is the point of no return */ | |
1da177e4 LT |
1126 | current->sas_ss_sp = current->sas_ss_size = 0; |
1127 | ||
da9592ed | 1128 | if (current_euid() == current_uid() && current_egid() == current_gid()) |
6c5d5238 | 1129 | set_dumpable(current->mm, 1); |
d6e71144 | 1130 | else |
6c5d5238 | 1131 | set_dumpable(current->mm, suid_dumpable); |
d6e71144 | 1132 | |
1da177e4 | 1133 | name = bprm->filename; |
36772092 PBG |
1134 | |
1135 | /* Copies the binary name from after last slash */ | |
1da177e4 LT |
1136 | for (i=0; (ch = *(name++)) != '\0';) { |
1137 | if (ch == '/') | |
36772092 | 1138 | i = 0; /* overwrite what we wrote */ |
1da177e4 LT |
1139 | else |
1140 | if (i < (sizeof(tcomm) - 1)) | |
1141 | tcomm[i++] = ch; | |
1142 | } | |
1143 | tcomm[i] = '\0'; | |
1144 | set_task_comm(current, tcomm); | |
1145 | ||
0551fbd2 BH |
1146 | /* Set the new mm task size. We have to do that late because it may |
1147 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
1148 | * some architectures like powerpc | |
1149 | */ | |
1150 | current->mm->task_size = TASK_SIZE; | |
1151 | ||
a6f76f23 DH |
1152 | /* install the new credentials */ |
1153 | if (bprm->cred->uid != current_euid() || | |
1154 | bprm->cred->gid != current_egid()) { | |
d2d56c5f | 1155 | current->pdeath_signal = 0; |
1b5d783c AV |
1156 | } else { |
1157 | would_dump(bprm, bprm->file); | |
1158 | if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) | |
1159 | set_dumpable(current->mm, suid_dumpable); | |
1da177e4 LT |
1160 | } |
1161 | ||
f65cb45c IM |
1162 | /* |
1163 | * Flush performance counters when crossing a | |
1164 | * security domain: | |
1165 | */ | |
1166 | if (!get_dumpable(current->mm)) | |
cdd6c482 | 1167 | perf_event_exit_task(current); |
f65cb45c | 1168 | |
1da177e4 LT |
1169 | /* An exec changes our domain. We are no longer part of the thread |
1170 | group */ | |
1171 | ||
1172 | current->self_exec_id++; | |
1173 | ||
1174 | flush_signal_handlers(current, 0); | |
1175 | flush_old_files(current->files); | |
1da177e4 | 1176 | } |
221af7f8 | 1177 | EXPORT_SYMBOL(setup_new_exec); |
1da177e4 | 1178 | |
a2a8474c ON |
1179 | /* |
1180 | * Prepare credentials and lock ->cred_guard_mutex. | |
1181 | * install_exec_creds() commits the new creds and drops the lock. | |
1182 | * Or, if exec fails before, free_bprm() should release ->cred and | |
1183 | * and unlock. | |
1184 | */ | |
1185 | int prepare_bprm_creds(struct linux_binprm *bprm) | |
1186 | { | |
9b1bf12d | 1187 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
a2a8474c ON |
1188 | return -ERESTARTNOINTR; |
1189 | ||
1190 | bprm->cred = prepare_exec_creds(); | |
1191 | if (likely(bprm->cred)) | |
1192 | return 0; | |
1193 | ||
9b1bf12d | 1194 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1195 | return -ENOMEM; |
1196 | } | |
1197 | ||
1198 | void free_bprm(struct linux_binprm *bprm) | |
1199 | { | |
1200 | free_arg_pages(bprm); | |
1201 | if (bprm->cred) { | |
9b1bf12d | 1202 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1203 | abort_creds(bprm->cred); |
1204 | } | |
1205 | kfree(bprm); | |
1206 | } | |
1207 | ||
a6f76f23 DH |
1208 | /* |
1209 | * install the new credentials for this executable | |
1210 | */ | |
1211 | void install_exec_creds(struct linux_binprm *bprm) | |
1212 | { | |
1213 | security_bprm_committing_creds(bprm); | |
1214 | ||
1215 | commit_creds(bprm->cred); | |
1216 | bprm->cred = NULL; | |
a2a8474c ON |
1217 | /* |
1218 | * cred_guard_mutex must be held at least to this point to prevent | |
a6f76f23 | 1219 | * ptrace_attach() from altering our determination of the task's |
a2a8474c ON |
1220 | * credentials; any time after this it may be unlocked. |
1221 | */ | |
a6f76f23 | 1222 | security_bprm_committed_creds(bprm); |
9b1bf12d | 1223 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a6f76f23 DH |
1224 | } |
1225 | EXPORT_SYMBOL(install_exec_creds); | |
1226 | ||
1227 | /* | |
1228 | * determine how safe it is to execute the proposed program | |
9b1bf12d | 1229 | * - the caller must hold ->cred_guard_mutex to protect against |
a6f76f23 DH |
1230 | * PTRACE_ATTACH |
1231 | */ | |
498052bb | 1232 | int check_unsafe_exec(struct linux_binprm *bprm) |
a6f76f23 | 1233 | { |
0bf2f3ae | 1234 | struct task_struct *p = current, *t; |
f1191b50 | 1235 | unsigned n_fs; |
498052bb | 1236 | int res = 0; |
a6f76f23 | 1237 | |
4b9d33e6 TH |
1238 | if (p->ptrace) { |
1239 | if (p->ptrace & PT_PTRACE_CAP) | |
1240 | bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP; | |
1241 | else | |
1242 | bprm->unsafe |= LSM_UNSAFE_PTRACE; | |
1243 | } | |
a6f76f23 | 1244 | |
0bf2f3ae | 1245 | n_fs = 1; |
2a4419b5 | 1246 | spin_lock(&p->fs->lock); |
437f7fdb | 1247 | rcu_read_lock(); |
0bf2f3ae DH |
1248 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
1249 | if (t->fs == p->fs) | |
1250 | n_fs++; | |
0bf2f3ae | 1251 | } |
437f7fdb | 1252 | rcu_read_unlock(); |
0bf2f3ae | 1253 | |
f1191b50 | 1254 | if (p->fs->users > n_fs) { |
a6f76f23 | 1255 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
498052bb | 1256 | } else { |
8c652f96 ON |
1257 | res = -EAGAIN; |
1258 | if (!p->fs->in_exec) { | |
1259 | p->fs->in_exec = 1; | |
1260 | res = 1; | |
1261 | } | |
498052bb | 1262 | } |
2a4419b5 | 1263 | spin_unlock(&p->fs->lock); |
498052bb AV |
1264 | |
1265 | return res; | |
a6f76f23 DH |
1266 | } |
1267 | ||
1da177e4 LT |
1268 | /* |
1269 | * Fill the binprm structure from the inode. | |
1270 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
a6f76f23 DH |
1271 | * |
1272 | * This may be called multiple times for binary chains (scripts for example). | |
1da177e4 LT |
1273 | */ |
1274 | int prepare_binprm(struct linux_binprm *bprm) | |
1275 | { | |
a6f76f23 | 1276 | umode_t mode; |
0f7fc9e4 | 1277 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
1278 | int retval; |
1279 | ||
1280 | mode = inode->i_mode; | |
1da177e4 LT |
1281 | if (bprm->file->f_op == NULL) |
1282 | return -EACCES; | |
1283 | ||
a6f76f23 DH |
1284 | /* clear any previous set[ug]id data from a previous binary */ |
1285 | bprm->cred->euid = current_euid(); | |
1286 | bprm->cred->egid = current_egid(); | |
1da177e4 | 1287 | |
a6f76f23 | 1288 | if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
1da177e4 LT |
1289 | /* Set-uid? */ |
1290 | if (mode & S_ISUID) { | |
a6f76f23 DH |
1291 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1292 | bprm->cred->euid = inode->i_uid; | |
1da177e4 LT |
1293 | } |
1294 | ||
1295 | /* Set-gid? */ | |
1296 | /* | |
1297 | * If setgid is set but no group execute bit then this | |
1298 | * is a candidate for mandatory locking, not a setgid | |
1299 | * executable. | |
1300 | */ | |
1301 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
a6f76f23 DH |
1302 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1303 | bprm->cred->egid = inode->i_gid; | |
1da177e4 LT |
1304 | } |
1305 | } | |
1306 | ||
1307 | /* fill in binprm security blob */ | |
a6f76f23 | 1308 | retval = security_bprm_set_creds(bprm); |
1da177e4 LT |
1309 | if (retval) |
1310 | return retval; | |
a6f76f23 | 1311 | bprm->cred_prepared = 1; |
1da177e4 | 1312 | |
a6f76f23 DH |
1313 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
1314 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); | |
1da177e4 LT |
1315 | } |
1316 | ||
1317 | EXPORT_SYMBOL(prepare_binprm); | |
1318 | ||
4fc75ff4 NP |
1319 | /* |
1320 | * Arguments are '\0' separated strings found at the location bprm->p | |
1321 | * points to; chop off the first by relocating brpm->p to right after | |
1322 | * the first '\0' encountered. | |
1323 | */ | |
b6a2fea3 | 1324 | int remove_arg_zero(struct linux_binprm *bprm) |
1da177e4 | 1325 | { |
b6a2fea3 OW |
1326 | int ret = 0; |
1327 | unsigned long offset; | |
1328 | char *kaddr; | |
1329 | struct page *page; | |
4fc75ff4 | 1330 | |
b6a2fea3 OW |
1331 | if (!bprm->argc) |
1332 | return 0; | |
1da177e4 | 1333 | |
b6a2fea3 OW |
1334 | do { |
1335 | offset = bprm->p & ~PAGE_MASK; | |
1336 | page = get_arg_page(bprm, bprm->p, 0); | |
1337 | if (!page) { | |
1338 | ret = -EFAULT; | |
1339 | goto out; | |
1340 | } | |
1341 | kaddr = kmap_atomic(page, KM_USER0); | |
4fc75ff4 | 1342 | |
b6a2fea3 OW |
1343 | for (; offset < PAGE_SIZE && kaddr[offset]; |
1344 | offset++, bprm->p++) | |
1345 | ; | |
4fc75ff4 | 1346 | |
b6a2fea3 OW |
1347 | kunmap_atomic(kaddr, KM_USER0); |
1348 | put_arg_page(page); | |
4fc75ff4 | 1349 | |
b6a2fea3 OW |
1350 | if (offset == PAGE_SIZE) |
1351 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); | |
1352 | } while (offset == PAGE_SIZE); | |
4fc75ff4 | 1353 | |
b6a2fea3 OW |
1354 | bprm->p++; |
1355 | bprm->argc--; | |
1356 | ret = 0; | |
4fc75ff4 | 1357 | |
b6a2fea3 OW |
1358 | out: |
1359 | return ret; | |
1da177e4 | 1360 | } |
1da177e4 LT |
1361 | EXPORT_SYMBOL(remove_arg_zero); |
1362 | ||
1363 | /* | |
1364 | * cycle the list of binary formats handler, until one recognizes the image | |
1365 | */ | |
1366 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1367 | { | |
85f33466 | 1368 | unsigned int depth = bprm->recursion_depth; |
1da177e4 LT |
1369 | int try,retval; |
1370 | struct linux_binfmt *fmt; | |
bb188d7e | 1371 | pid_t old_pid; |
1da177e4 | 1372 | |
1da177e4 LT |
1373 | retval = security_bprm_check(bprm); |
1374 | if (retval) | |
1375 | return retval; | |
1376 | ||
473ae30b AV |
1377 | retval = audit_bprm(bprm); |
1378 | if (retval) | |
1379 | return retval; | |
1380 | ||
bb188d7e DV |
1381 | /* Need to fetch pid before load_binary changes it */ |
1382 | rcu_read_lock(); | |
1383 | old_pid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); | |
1384 | rcu_read_unlock(); | |
1385 | ||
1da177e4 LT |
1386 | retval = -ENOENT; |
1387 | for (try=0; try<2; try++) { | |
1388 | read_lock(&binfmt_lock); | |
e4dc1b14 | 1389 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
1390 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
1391 | if (!fn) | |
1392 | continue; | |
1393 | if (!try_module_get(fmt->module)) | |
1394 | continue; | |
1395 | read_unlock(&binfmt_lock); | |
1396 | retval = fn(bprm, regs); | |
85f33466 RM |
1397 | /* |
1398 | * Restore the depth counter to its starting value | |
1399 | * in this call, so we don't have to rely on every | |
1400 | * load_binary function to restore it on return. | |
1401 | */ | |
1402 | bprm->recursion_depth = depth; | |
1da177e4 | 1403 | if (retval >= 0) { |
85f33466 | 1404 | if (depth == 0) |
bb188d7e DV |
1405 | ptrace_event(PTRACE_EVENT_EXEC, |
1406 | old_pid); | |
1da177e4 LT |
1407 | put_binfmt(fmt); |
1408 | allow_write_access(bprm->file); | |
1409 | if (bprm->file) | |
1410 | fput(bprm->file); | |
1411 | bprm->file = NULL; | |
1412 | current->did_exec = 1; | |
9f46080c | 1413 | proc_exec_connector(current); |
1da177e4 LT |
1414 | return retval; |
1415 | } | |
1416 | read_lock(&binfmt_lock); | |
1417 | put_binfmt(fmt); | |
1418 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1419 | break; | |
1420 | if (!bprm->file) { | |
1421 | read_unlock(&binfmt_lock); | |
1422 | return retval; | |
1423 | } | |
1424 | } | |
1425 | read_unlock(&binfmt_lock); | |
b4edf8bd | 1426 | #ifdef CONFIG_MODULES |
1da177e4 LT |
1427 | if (retval != -ENOEXEC || bprm->mm == NULL) { |
1428 | break; | |
5f4123be | 1429 | } else { |
1da177e4 LT |
1430 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
1431 | if (printable(bprm->buf[0]) && | |
1432 | printable(bprm->buf[1]) && | |
1433 | printable(bprm->buf[2]) && | |
1434 | printable(bprm->buf[3])) | |
1435 | break; /* -ENOEXEC */ | |
91219352 TH |
1436 | if (try) |
1437 | break; /* -ENOEXEC */ | |
1da177e4 | 1438 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); |
1da177e4 | 1439 | } |
b4edf8bd TH |
1440 | #else |
1441 | break; | |
1442 | #endif | |
1da177e4 LT |
1443 | } |
1444 | return retval; | |
1445 | } | |
1446 | ||
1447 | EXPORT_SYMBOL(search_binary_handler); | |
1448 | ||
1449 | /* | |
1450 | * sys_execve() executes a new program. | |
1451 | */ | |
ba2d0162 ON |
1452 | static int do_execve_common(const char *filename, |
1453 | struct user_arg_ptr argv, | |
1454 | struct user_arg_ptr envp, | |
1455 | struct pt_regs *regs) | |
1da177e4 LT |
1456 | { |
1457 | struct linux_binprm *bprm; | |
1458 | struct file *file; | |
3b125388 | 1459 | struct files_struct *displaced; |
8c652f96 | 1460 | bool clear_in_exec; |
1da177e4 | 1461 | int retval; |
72fa5997 VK |
1462 | const struct cred *cred = current_cred(); |
1463 | ||
1464 | /* | |
1465 | * We move the actual failure in case of RLIMIT_NPROC excess from | |
1466 | * set*uid() to execve() because too many poorly written programs | |
1467 | * don't check setuid() return code. Here we additionally recheck | |
1468 | * whether NPROC limit is still exceeded. | |
1469 | */ | |
1470 | if ((current->flags & PF_NPROC_EXCEEDED) && | |
1471 | atomic_read(&cred->user->processes) > rlimit(RLIMIT_NPROC)) { | |
1472 | retval = -EAGAIN; | |
1473 | goto out_ret; | |
1474 | } | |
1475 | ||
1476 | /* We're below the limit (still or again), so we don't want to make | |
1477 | * further execve() calls fail. */ | |
1478 | current->flags &= ~PF_NPROC_EXCEEDED; | |
1da177e4 | 1479 | |
3b125388 | 1480 | retval = unshare_files(&displaced); |
fd8328be AV |
1481 | if (retval) |
1482 | goto out_ret; | |
1483 | ||
1da177e4 | 1484 | retval = -ENOMEM; |
11b0b5ab | 1485 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1da177e4 | 1486 | if (!bprm) |
fd8328be | 1487 | goto out_files; |
1da177e4 | 1488 | |
a2a8474c ON |
1489 | retval = prepare_bprm_creds(bprm); |
1490 | if (retval) | |
a6f76f23 | 1491 | goto out_free; |
498052bb AV |
1492 | |
1493 | retval = check_unsafe_exec(bprm); | |
8c652f96 | 1494 | if (retval < 0) |
a2a8474c | 1495 | goto out_free; |
8c652f96 | 1496 | clear_in_exec = retval; |
a2a8474c | 1497 | current->in_execve = 1; |
a6f76f23 | 1498 | |
1da177e4 LT |
1499 | file = open_exec(filename); |
1500 | retval = PTR_ERR(file); | |
1501 | if (IS_ERR(file)) | |
498052bb | 1502 | goto out_unmark; |
1da177e4 LT |
1503 | |
1504 | sched_exec(); | |
1505 | ||
1da177e4 LT |
1506 | bprm->file = file; |
1507 | bprm->filename = filename; | |
1508 | bprm->interp = filename; | |
1da177e4 | 1509 | |
b6a2fea3 OW |
1510 | retval = bprm_mm_init(bprm); |
1511 | if (retval) | |
1512 | goto out_file; | |
1da177e4 | 1513 | |
b6a2fea3 | 1514 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
1da177e4 | 1515 | if ((retval = bprm->argc) < 0) |
a6f76f23 | 1516 | goto out; |
1da177e4 | 1517 | |
b6a2fea3 | 1518 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
1da177e4 | 1519 | if ((retval = bprm->envc) < 0) |
1da177e4 LT |
1520 | goto out; |
1521 | ||
1522 | retval = prepare_binprm(bprm); | |
1523 | if (retval < 0) | |
1524 | goto out; | |
1525 | ||
1526 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1527 | if (retval < 0) | |
1528 | goto out; | |
1529 | ||
1530 | bprm->exec = bprm->p; | |
1531 | retval = copy_strings(bprm->envc, envp, bprm); | |
1532 | if (retval < 0) | |
1533 | goto out; | |
1534 | ||
1535 | retval = copy_strings(bprm->argc, argv, bprm); | |
1536 | if (retval < 0) | |
1537 | goto out; | |
1538 | ||
1539 | retval = search_binary_handler(bprm,regs); | |
a6f76f23 DH |
1540 | if (retval < 0) |
1541 | goto out; | |
1da177e4 | 1542 | |
a6f76f23 | 1543 | /* execve succeeded */ |
498052bb | 1544 | current->fs->in_exec = 0; |
f9ce1f1c | 1545 | current->in_execve = 0; |
a6f76f23 DH |
1546 | acct_update_integrals(current); |
1547 | free_bprm(bprm); | |
1548 | if (displaced) | |
1549 | put_files_struct(displaced); | |
1550 | return retval; | |
1da177e4 | 1551 | |
a6f76f23 | 1552 | out: |
3c77f845 ON |
1553 | if (bprm->mm) { |
1554 | acct_arg_size(bprm, 0); | |
1555 | mmput(bprm->mm); | |
1556 | } | |
1da177e4 LT |
1557 | |
1558 | out_file: | |
1559 | if (bprm->file) { | |
1560 | allow_write_access(bprm->file); | |
1561 | fput(bprm->file); | |
1562 | } | |
a6f76f23 | 1563 | |
498052bb | 1564 | out_unmark: |
8c652f96 ON |
1565 | if (clear_in_exec) |
1566 | current->fs->in_exec = 0; | |
f9ce1f1c | 1567 | current->in_execve = 0; |
a6f76f23 DH |
1568 | |
1569 | out_free: | |
08a6fac1 | 1570 | free_bprm(bprm); |
1da177e4 | 1571 | |
fd8328be | 1572 | out_files: |
3b125388 AV |
1573 | if (displaced) |
1574 | reset_files_struct(displaced); | |
1da177e4 LT |
1575 | out_ret: |
1576 | return retval; | |
1577 | } | |
1578 | ||
ba2d0162 ON |
1579 | int do_execve(const char *filename, |
1580 | const char __user *const __user *__argv, | |
1581 | const char __user *const __user *__envp, | |
1582 | struct pt_regs *regs) | |
1583 | { | |
0e028465 ON |
1584 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
1585 | struct user_arg_ptr envp = { .ptr.native = __envp }; | |
1586 | return do_execve_common(filename, argv, envp, regs); | |
1587 | } | |
1588 | ||
1589 | #ifdef CONFIG_COMPAT | |
1590 | int compat_do_execve(char *filename, | |
1591 | compat_uptr_t __user *__argv, | |
1592 | compat_uptr_t __user *__envp, | |
1593 | struct pt_regs *regs) | |
1594 | { | |
1595 | struct user_arg_ptr argv = { | |
1596 | .is_compat = true, | |
1597 | .ptr.compat = __argv, | |
1598 | }; | |
1599 | struct user_arg_ptr envp = { | |
1600 | .is_compat = true, | |
1601 | .ptr.compat = __envp, | |
1602 | }; | |
ba2d0162 ON |
1603 | return do_execve_common(filename, argv, envp, regs); |
1604 | } | |
0e028465 | 1605 | #endif |
ba2d0162 | 1606 | |
964ee7df | 1607 | void set_binfmt(struct linux_binfmt *new) |
1da177e4 | 1608 | { |
801460d0 HS |
1609 | struct mm_struct *mm = current->mm; |
1610 | ||
1611 | if (mm->binfmt) | |
1612 | module_put(mm->binfmt->module); | |
1da177e4 | 1613 | |
801460d0 | 1614 | mm->binfmt = new; |
964ee7df ON |
1615 | if (new) |
1616 | __module_get(new->module); | |
1da177e4 LT |
1617 | } |
1618 | ||
1619 | EXPORT_SYMBOL(set_binfmt); | |
1620 | ||
1b0d300b XF |
1621 | static int expand_corename(struct core_name *cn) |
1622 | { | |
1623 | char *old_corename = cn->corename; | |
1624 | ||
1625 | cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count); | |
1626 | cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL); | |
1627 | ||
1628 | if (!cn->corename) { | |
1629 | kfree(old_corename); | |
1630 | return -ENOMEM; | |
1631 | } | |
1632 | ||
1633 | return 0; | |
1634 | } | |
1635 | ||
1636 | static int cn_printf(struct core_name *cn, const char *fmt, ...) | |
1637 | { | |
1638 | char *cur; | |
1639 | int need; | |
1640 | int ret; | |
1641 | va_list arg; | |
1642 | ||
1643 | va_start(arg, fmt); | |
1644 | need = vsnprintf(NULL, 0, fmt, arg); | |
1645 | va_end(arg); | |
1646 | ||
1647 | if (likely(need < cn->size - cn->used - 1)) | |
1648 | goto out_printf; | |
1649 | ||
1650 | ret = expand_corename(cn); | |
1651 | if (ret) | |
1652 | goto expand_fail; | |
1653 | ||
1654 | out_printf: | |
1655 | cur = cn->corename + cn->used; | |
1656 | va_start(arg, fmt); | |
1657 | vsnprintf(cur, need + 1, fmt, arg); | |
1658 | va_end(arg); | |
1659 | cn->used += need; | |
1660 | return 0; | |
1661 | ||
1662 | expand_fail: | |
1663 | return ret; | |
1664 | } | |
1665 | ||
2c563731 JS |
1666 | static void cn_escape(char *str) |
1667 | { | |
1668 | for (; *str; str++) | |
1669 | if (*str == '/') | |
1670 | *str = '!'; | |
1671 | } | |
1672 | ||
57cc083a JS |
1673 | static int cn_print_exe_file(struct core_name *cn) |
1674 | { | |
1675 | struct file *exe_file; | |
2c563731 | 1676 | char *pathbuf, *path; |
57cc083a JS |
1677 | int ret; |
1678 | ||
1679 | exe_file = get_mm_exe_file(current->mm); | |
2c563731 JS |
1680 | if (!exe_file) { |
1681 | char *commstart = cn->corename + cn->used; | |
1682 | ret = cn_printf(cn, "%s (path unknown)", current->comm); | |
1683 | cn_escape(commstart); | |
1684 | return ret; | |
1685 | } | |
57cc083a JS |
1686 | |
1687 | pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY); | |
1688 | if (!pathbuf) { | |
1689 | ret = -ENOMEM; | |
1690 | goto put_exe_file; | |
1691 | } | |
1692 | ||
1693 | path = d_path(&exe_file->f_path, pathbuf, PATH_MAX); | |
1694 | if (IS_ERR(path)) { | |
1695 | ret = PTR_ERR(path); | |
1696 | goto free_buf; | |
1697 | } | |
1698 | ||
2c563731 | 1699 | cn_escape(path); |
57cc083a JS |
1700 | |
1701 | ret = cn_printf(cn, "%s", path); | |
1702 | ||
1703 | free_buf: | |
1704 | kfree(pathbuf); | |
1705 | put_exe_file: | |
1706 | fput(exe_file); | |
1707 | return ret; | |
1708 | } | |
1709 | ||
1da177e4 LT |
1710 | /* format_corename will inspect the pattern parameter, and output a |
1711 | * name into corename, which must have space for at least | |
1712 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
1713 | */ | |
1b0d300b | 1714 | static int format_corename(struct core_name *cn, long signr) |
1da177e4 | 1715 | { |
86a264ab | 1716 | const struct cred *cred = current_cred(); |
565b9b14 ON |
1717 | const char *pat_ptr = core_pattern; |
1718 | int ispipe = (*pat_ptr == '|'); | |
1da177e4 | 1719 | int pid_in_pattern = 0; |
1b0d300b XF |
1720 | int err = 0; |
1721 | ||
1722 | cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count); | |
1723 | cn->corename = kmalloc(cn->size, GFP_KERNEL); | |
1724 | cn->used = 0; | |
1725 | ||
1726 | if (!cn->corename) | |
1727 | return -ENOMEM; | |
1da177e4 LT |
1728 | |
1729 | /* Repeat as long as we have more pattern to process and more output | |
1730 | space */ | |
1731 | while (*pat_ptr) { | |
1732 | if (*pat_ptr != '%') { | |
1b0d300b | 1733 | if (*pat_ptr == 0) |
1da177e4 | 1734 | goto out; |
1b0d300b | 1735 | err = cn_printf(cn, "%c", *pat_ptr++); |
1da177e4 LT |
1736 | } else { |
1737 | switch (*++pat_ptr) { | |
1b0d300b | 1738 | /* single % at the end, drop that */ |
1da177e4 LT |
1739 | case 0: |
1740 | goto out; | |
1741 | /* Double percent, output one percent */ | |
1742 | case '%': | |
1b0d300b | 1743 | err = cn_printf(cn, "%c", '%'); |
1da177e4 LT |
1744 | break; |
1745 | /* pid */ | |
1746 | case 'p': | |
1747 | pid_in_pattern = 1; | |
1b0d300b XF |
1748 | err = cn_printf(cn, "%d", |
1749 | task_tgid_vnr(current)); | |
1da177e4 LT |
1750 | break; |
1751 | /* uid */ | |
1752 | case 'u': | |
1b0d300b | 1753 | err = cn_printf(cn, "%d", cred->uid); |
1da177e4 LT |
1754 | break; |
1755 | /* gid */ | |
1756 | case 'g': | |
1b0d300b | 1757 | err = cn_printf(cn, "%d", cred->gid); |
1da177e4 LT |
1758 | break; |
1759 | /* signal that caused the coredump */ | |
1760 | case 's': | |
1b0d300b | 1761 | err = cn_printf(cn, "%ld", signr); |
1da177e4 LT |
1762 | break; |
1763 | /* UNIX time of coredump */ | |
1764 | case 't': { | |
1765 | struct timeval tv; | |
1766 | do_gettimeofday(&tv); | |
1b0d300b | 1767 | err = cn_printf(cn, "%lu", tv.tv_sec); |
1da177e4 LT |
1768 | break; |
1769 | } | |
1770 | /* hostname */ | |
2c563731 JS |
1771 | case 'h': { |
1772 | char *namestart = cn->corename + cn->used; | |
1da177e4 | 1773 | down_read(&uts_sem); |
1b0d300b XF |
1774 | err = cn_printf(cn, "%s", |
1775 | utsname()->nodename); | |
1da177e4 | 1776 | up_read(&uts_sem); |
2c563731 | 1777 | cn_escape(namestart); |
1da177e4 | 1778 | break; |
2c563731 | 1779 | } |
1da177e4 | 1780 | /* executable */ |
2c563731 JS |
1781 | case 'e': { |
1782 | char *commstart = cn->corename + cn->used; | |
1b0d300b | 1783 | err = cn_printf(cn, "%s", current->comm); |
2c563731 | 1784 | cn_escape(commstart); |
1da177e4 | 1785 | break; |
2c563731 | 1786 | } |
57cc083a JS |
1787 | case 'E': |
1788 | err = cn_print_exe_file(cn); | |
1789 | break; | |
74aadce9 NH |
1790 | /* core limit size */ |
1791 | case 'c': | |
1b0d300b XF |
1792 | err = cn_printf(cn, "%lu", |
1793 | rlimit(RLIMIT_CORE)); | |
74aadce9 | 1794 | break; |
1da177e4 LT |
1795 | default: |
1796 | break; | |
1797 | } | |
1798 | ++pat_ptr; | |
1799 | } | |
1b0d300b XF |
1800 | |
1801 | if (err) | |
1802 | return err; | |
1da177e4 | 1803 | } |
1b0d300b | 1804 | |
1da177e4 LT |
1805 | /* Backward compatibility with core_uses_pid: |
1806 | * | |
1807 | * If core_pattern does not include a %p (as is the default) | |
1808 | * and core_uses_pid is set, then .%pid will be appended to | |
c4bbafda | 1809 | * the filename. Do not do this for piped commands. */ |
6409324b | 1810 | if (!ispipe && !pid_in_pattern && core_uses_pid) { |
1b0d300b XF |
1811 | err = cn_printf(cn, ".%d", task_tgid_vnr(current)); |
1812 | if (err) | |
1813 | return err; | |
1da177e4 | 1814 | } |
c4bbafda | 1815 | out: |
c4bbafda | 1816 | return ispipe; |
1da177e4 LT |
1817 | } |
1818 | ||
5c99cbf4 | 1819 | static int zap_process(struct task_struct *start, int exit_code) |
aceecc04 ON |
1820 | { |
1821 | struct task_struct *t; | |
8cd9c249 | 1822 | int nr = 0; |
281de339 | 1823 | |
d5f70c00 | 1824 | start->signal->flags = SIGNAL_GROUP_EXIT; |
5c99cbf4 | 1825 | start->signal->group_exit_code = exit_code; |
d5f70c00 | 1826 | start->signal->group_stop_count = 0; |
aceecc04 ON |
1827 | |
1828 | t = start; | |
1829 | do { | |
6dfca329 | 1830 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
aceecc04 | 1831 | if (t != current && t->mm) { |
281de339 ON |
1832 | sigaddset(&t->pending.signal, SIGKILL); |
1833 | signal_wake_up(t, 1); | |
8cd9c249 | 1834 | nr++; |
aceecc04 | 1835 | } |
e4901f92 | 1836 | } while_each_thread(start, t); |
8cd9c249 ON |
1837 | |
1838 | return nr; | |
aceecc04 ON |
1839 | } |
1840 | ||
dcf560c5 | 1841 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
8cd9c249 | 1842 | struct core_state *core_state, int exit_code) |
1da177e4 LT |
1843 | { |
1844 | struct task_struct *g, *p; | |
5debfa6d | 1845 | unsigned long flags; |
8cd9c249 | 1846 | int nr = -EAGAIN; |
dcf560c5 ON |
1847 | |
1848 | spin_lock_irq(&tsk->sighand->siglock); | |
ed5d2cac | 1849 | if (!signal_group_exit(tsk->signal)) { |
8cd9c249 | 1850 | mm->core_state = core_state; |
5c99cbf4 | 1851 | nr = zap_process(tsk, exit_code); |
1da177e4 | 1852 | } |
dcf560c5 | 1853 | spin_unlock_irq(&tsk->sighand->siglock); |
8cd9c249 ON |
1854 | if (unlikely(nr < 0)) |
1855 | return nr; | |
1da177e4 | 1856 | |
8cd9c249 | 1857 | if (atomic_read(&mm->mm_users) == nr + 1) |
5debfa6d | 1858 | goto done; |
e4901f92 ON |
1859 | /* |
1860 | * We should find and kill all tasks which use this mm, and we should | |
999d9fc1 | 1861 | * count them correctly into ->nr_threads. We don't take tasklist |
e4901f92 ON |
1862 | * lock, but this is safe wrt: |
1863 | * | |
1864 | * fork: | |
1865 | * None of sub-threads can fork after zap_process(leader). All | |
1866 | * processes which were created before this point should be | |
1867 | * visible to zap_threads() because copy_process() adds the new | |
1868 | * process to the tail of init_task.tasks list, and lock/unlock | |
1869 | * of ->siglock provides a memory barrier. | |
1870 | * | |
1871 | * do_exit: | |
1872 | * The caller holds mm->mmap_sem. This means that the task which | |
1873 | * uses this mm can't pass exit_mm(), so it can't exit or clear | |
1874 | * its ->mm. | |
1875 | * | |
1876 | * de_thread: | |
1877 | * It does list_replace_rcu(&leader->tasks, ¤t->tasks), | |
1878 | * we must see either old or new leader, this does not matter. | |
1879 | * However, it can change p->sighand, so lock_task_sighand(p) | |
1880 | * must be used. Since p->mm != NULL and we hold ->mmap_sem | |
1881 | * it can't fail. | |
1882 | * | |
1883 | * Note also that "g" can be the old leader with ->mm == NULL | |
1884 | * and already unhashed and thus removed from ->thread_group. | |
1885 | * This is OK, __unhash_process()->list_del_rcu() does not | |
1886 | * clear the ->next pointer, we will find the new leader via | |
1887 | * next_thread(). | |
1888 | */ | |
7b1c6154 | 1889 | rcu_read_lock(); |
aceecc04 | 1890 | for_each_process(g) { |
5debfa6d ON |
1891 | if (g == tsk->group_leader) |
1892 | continue; | |
15b9f360 ON |
1893 | if (g->flags & PF_KTHREAD) |
1894 | continue; | |
aceecc04 ON |
1895 | p = g; |
1896 | do { | |
1897 | if (p->mm) { | |
15b9f360 | 1898 | if (unlikely(p->mm == mm)) { |
5debfa6d | 1899 | lock_task_sighand(p, &flags); |
5c99cbf4 | 1900 | nr += zap_process(p, exit_code); |
5debfa6d ON |
1901 | unlock_task_sighand(p, &flags); |
1902 | } | |
aceecc04 ON |
1903 | break; |
1904 | } | |
e4901f92 | 1905 | } while_each_thread(g, p); |
aceecc04 | 1906 | } |
7b1c6154 | 1907 | rcu_read_unlock(); |
5debfa6d | 1908 | done: |
c5f1cc8c | 1909 | atomic_set(&core_state->nr_threads, nr); |
8cd9c249 | 1910 | return nr; |
1da177e4 LT |
1911 | } |
1912 | ||
9d5b327b | 1913 | static int coredump_wait(int exit_code, struct core_state *core_state) |
1da177e4 | 1914 | { |
dcf560c5 ON |
1915 | struct task_struct *tsk = current; |
1916 | struct mm_struct *mm = tsk->mm; | |
dcf560c5 | 1917 | struct completion *vfork_done; |
269b005a | 1918 | int core_waiters = -EBUSY; |
1da177e4 | 1919 | |
9d5b327b | 1920 | init_completion(&core_state->startup); |
b564daf8 ON |
1921 | core_state->dumper.task = tsk; |
1922 | core_state->dumper.next = NULL; | |
269b005a ON |
1923 | |
1924 | down_write(&mm->mmap_sem); | |
1925 | if (!mm->core_state) | |
1926 | core_waiters = zap_threads(tsk, mm, core_state, exit_code); | |
2384f55f ON |
1927 | up_write(&mm->mmap_sem); |
1928 | ||
dcf560c5 ON |
1929 | if (unlikely(core_waiters < 0)) |
1930 | goto fail; | |
1931 | ||
1932 | /* | |
1933 | * Make sure nobody is waiting for us to release the VM, | |
1934 | * otherwise we can deadlock when we wait on each other | |
1935 | */ | |
1936 | vfork_done = tsk->vfork_done; | |
1937 | if (vfork_done) { | |
1938 | tsk->vfork_done = NULL; | |
1939 | complete(vfork_done); | |
1940 | } | |
1941 | ||
2384f55f | 1942 | if (core_waiters) |
9d5b327b | 1943 | wait_for_completion(&core_state->startup); |
dcf560c5 | 1944 | fail: |
dcf560c5 | 1945 | return core_waiters; |
1da177e4 LT |
1946 | } |
1947 | ||
a94e2d40 ON |
1948 | static void coredump_finish(struct mm_struct *mm) |
1949 | { | |
1950 | struct core_thread *curr, *next; | |
1951 | struct task_struct *task; | |
1952 | ||
1953 | next = mm->core_state->dumper.next; | |
1954 | while ((curr = next) != NULL) { | |
1955 | next = curr->next; | |
1956 | task = curr->task; | |
1957 | /* | |
1958 | * see exit_mm(), curr->task must not see | |
1959 | * ->task == NULL before we read ->next. | |
1960 | */ | |
1961 | smp_mb(); | |
1962 | curr->task = NULL; | |
1963 | wake_up_process(task); | |
1964 | } | |
1965 | ||
1966 | mm->core_state = NULL; | |
1967 | } | |
1968 | ||
6c5d5238 KH |
1969 | /* |
1970 | * set_dumpable converts traditional three-value dumpable to two flags and | |
1971 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but | |
1972 | * these bits are not changed atomically. So get_dumpable can observe the | |
1973 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable | |
1974 | * return either old dumpable or new one by paying attention to the order of | |
1975 | * modifying the bits. | |
1976 | * | |
1977 | * dumpable | mm->flags (binary) | |
1978 | * old new | initial interim final | |
1979 | * ---------+----------------------- | |
1980 | * 0 1 | 00 01 01 | |
1981 | * 0 2 | 00 10(*) 11 | |
1982 | * 1 0 | 01 00 00 | |
1983 | * 1 2 | 01 11 11 | |
1984 | * 2 0 | 11 10(*) 00 | |
1985 | * 2 1 | 11 11 01 | |
1986 | * | |
1987 | * (*) get_dumpable regards interim value of 10 as 11. | |
1988 | */ | |
1989 | void set_dumpable(struct mm_struct *mm, int value) | |
1990 | { | |
1991 | switch (value) { | |
1992 | case 0: | |
1993 | clear_bit(MMF_DUMPABLE, &mm->flags); | |
1994 | smp_wmb(); | |
1995 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1996 | break; | |
1997 | case 1: | |
1998 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1999 | smp_wmb(); | |
2000 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
2001 | break; | |
2002 | case 2: | |
2003 | set_bit(MMF_DUMP_SECURELY, &mm->flags); | |
2004 | smp_wmb(); | |
2005 | set_bit(MMF_DUMPABLE, &mm->flags); | |
2006 | break; | |
2007 | } | |
2008 | } | |
6c5d5238 | 2009 | |
30736a4d | 2010 | static int __get_dumpable(unsigned long mm_flags) |
6c5d5238 KH |
2011 | { |
2012 | int ret; | |
2013 | ||
30736a4d | 2014 | ret = mm_flags & MMF_DUMPABLE_MASK; |
6c5d5238 KH |
2015 | return (ret >= 2) ? 2 : ret; |
2016 | } | |
2017 | ||
30736a4d MH |
2018 | int get_dumpable(struct mm_struct *mm) |
2019 | { | |
2020 | return __get_dumpable(mm->flags); | |
2021 | } | |
2022 | ||
61be228a NH |
2023 | static void wait_for_dump_helpers(struct file *file) |
2024 | { | |
2025 | struct pipe_inode_info *pipe; | |
2026 | ||
2027 | pipe = file->f_path.dentry->d_inode->i_pipe; | |
2028 | ||
2029 | pipe_lock(pipe); | |
2030 | pipe->readers++; | |
2031 | pipe->writers--; | |
2032 | ||
2033 | while ((pipe->readers > 1) && (!signal_pending(current))) { | |
2034 | wake_up_interruptible_sync(&pipe->wait); | |
2035 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); | |
2036 | pipe_wait(pipe); | |
2037 | } | |
2038 | ||
2039 | pipe->readers--; | |
2040 | pipe->writers++; | |
2041 | pipe_unlock(pipe); | |
2042 | ||
2043 | } | |
2044 | ||
2045 | ||
898b374a | 2046 | /* |
1bef8291 | 2047 | * umh_pipe_setup |
898b374a NH |
2048 | * helper function to customize the process used |
2049 | * to collect the core in userspace. Specifically | |
2050 | * it sets up a pipe and installs it as fd 0 (stdin) | |
2051 | * for the process. Returns 0 on success, or | |
2052 | * PTR_ERR on failure. | |
2053 | * Note that it also sets the core limit to 1. This | |
2054 | * is a special value that we use to trap recursive | |
2055 | * core dumps | |
2056 | */ | |
87966996 | 2057 | static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) |
898b374a NH |
2058 | { |
2059 | struct file *rp, *wp; | |
2060 | struct fdtable *fdt; | |
2061 | struct coredump_params *cp = (struct coredump_params *)info->data; | |
2062 | struct files_struct *cf = current->files; | |
2063 | ||
2064 | wp = create_write_pipe(0); | |
2065 | if (IS_ERR(wp)) | |
2066 | return PTR_ERR(wp); | |
2067 | ||
2068 | rp = create_read_pipe(wp, 0); | |
2069 | if (IS_ERR(rp)) { | |
2070 | free_write_pipe(wp); | |
2071 | return PTR_ERR(rp); | |
2072 | } | |
2073 | ||
2074 | cp->file = wp; | |
2075 | ||
2076 | sys_close(0); | |
2077 | fd_install(0, rp); | |
2078 | spin_lock(&cf->file_lock); | |
2079 | fdt = files_fdtable(cf); | |
2080 | FD_SET(0, fdt->open_fds); | |
2081 | FD_CLR(0, fdt->close_on_exec); | |
2082 | spin_unlock(&cf->file_lock); | |
2083 | ||
2084 | /* and disallow core files too */ | |
2085 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; | |
2086 | ||
2087 | return 0; | |
2088 | } | |
2089 | ||
8cd3ac3a | 2090 | void do_coredump(long signr, int exit_code, struct pt_regs *regs) |
1da177e4 | 2091 | { |
9d5b327b | 2092 | struct core_state core_state; |
1b0d300b | 2093 | struct core_name cn; |
1da177e4 LT |
2094 | struct mm_struct *mm = current->mm; |
2095 | struct linux_binfmt * binfmt; | |
d84f4f99 DH |
2096 | const struct cred *old_cred; |
2097 | struct cred *cred; | |
1da177e4 | 2098 | int retval = 0; |
d6e71144 | 2099 | int flag = 0; |
d5bf4c4f | 2100 | int ispipe; |
a293980c | 2101 | static atomic_t core_dump_count = ATOMIC_INIT(0); |
f6151dfe MH |
2102 | struct coredump_params cprm = { |
2103 | .signr = signr, | |
2104 | .regs = regs, | |
d554ed89 | 2105 | .limit = rlimit(RLIMIT_CORE), |
30736a4d MH |
2106 | /* |
2107 | * We must use the same mm->flags while dumping core to avoid | |
2108 | * inconsistency of bit flags, since this flag is not protected | |
2109 | * by any locks. | |
2110 | */ | |
2111 | .mm_flags = mm->flags, | |
f6151dfe | 2112 | }; |
1da177e4 | 2113 | |
0a4ff8c2 SG |
2114 | audit_core_dumps(signr); |
2115 | ||
801460d0 | 2116 | binfmt = mm->binfmt; |
1da177e4 LT |
2117 | if (!binfmt || !binfmt->core_dump) |
2118 | goto fail; | |
269b005a ON |
2119 | if (!__get_dumpable(cprm.mm_flags)) |
2120 | goto fail; | |
d84f4f99 DH |
2121 | |
2122 | cred = prepare_creds(); | |
5e43aef5 | 2123 | if (!cred) |
d84f4f99 | 2124 | goto fail; |
d6e71144 AC |
2125 | /* |
2126 | * We cannot trust fsuid as being the "true" uid of the | |
2127 | * process nor do we know its entire history. We only know it | |
2128 | * was tainted so we dump it as root in mode 2. | |
2129 | */ | |
30736a4d MH |
2130 | if (__get_dumpable(cprm.mm_flags) == 2) { |
2131 | /* Setuid core dump mode */ | |
d6e71144 | 2132 | flag = O_EXCL; /* Stop rewrite attacks */ |
d84f4f99 | 2133 | cred->fsuid = 0; /* Dump root private */ |
d6e71144 | 2134 | } |
1291cf41 | 2135 | |
9d5b327b | 2136 | retval = coredump_wait(exit_code, &core_state); |
5e43aef5 ON |
2137 | if (retval < 0) |
2138 | goto fail_creds; | |
d84f4f99 DH |
2139 | |
2140 | old_cred = override_creds(cred); | |
1da177e4 LT |
2141 | |
2142 | /* | |
2143 | * Clear any false indication of pending signals that might | |
2144 | * be seen by the filesystem code called to write the core file. | |
2145 | */ | |
1da177e4 LT |
2146 | clear_thread_flag(TIF_SIGPENDING); |
2147 | ||
1b0d300b XF |
2148 | ispipe = format_corename(&cn, signr); |
2149 | ||
c4bbafda | 2150 | if (ispipe) { |
d5bf4c4f ON |
2151 | int dump_count; |
2152 | char **helper_argv; | |
2153 | ||
99b64567 ON |
2154 | if (ispipe < 0) { |
2155 | printk(KERN_WARNING "format_corename failed\n"); | |
2156 | printk(KERN_WARNING "Aborting core\n"); | |
2157 | goto fail_corename; | |
2158 | } | |
2159 | ||
898b374a | 2160 | if (cprm.limit == 1) { |
725eae32 NH |
2161 | /* |
2162 | * Normally core limits are irrelevant to pipes, since | |
2163 | * we're not writing to the file system, but we use | |
898b374a NH |
2164 | * cprm.limit of 1 here as a speacial value. Any |
2165 | * non-1 limit gets set to RLIM_INFINITY below, but | |
725eae32 NH |
2166 | * a limit of 0 skips the dump. This is a consistent |
2167 | * way to catch recursive crashes. We can still crash | |
898b374a | 2168 | * if the core_pattern binary sets RLIM_CORE = !1 |
725eae32 NH |
2169 | * but it runs as root, and can do lots of stupid things |
2170 | * Note that we use task_tgid_vnr here to grab the pid | |
2171 | * of the process group leader. That way we get the | |
2172 | * right pid if a thread in a multi-threaded | |
2173 | * core_pattern process dies. | |
2174 | */ | |
2175 | printk(KERN_WARNING | |
898b374a | 2176 | "Process %d(%s) has RLIMIT_CORE set to 1\n", |
725eae32 NH |
2177 | task_tgid_vnr(current), current->comm); |
2178 | printk(KERN_WARNING "Aborting core\n"); | |
2179 | goto fail_unlock; | |
2180 | } | |
d5bf4c4f | 2181 | cprm.limit = RLIM_INFINITY; |
725eae32 | 2182 | |
a293980c NH |
2183 | dump_count = atomic_inc_return(&core_dump_count); |
2184 | if (core_pipe_limit && (core_pipe_limit < dump_count)) { | |
2185 | printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", | |
2186 | task_tgid_vnr(current), current->comm); | |
2187 | printk(KERN_WARNING "Skipping core dump\n"); | |
2188 | goto fail_dropcount; | |
2189 | } | |
2190 | ||
1b0d300b | 2191 | helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL); |
350eaf79 TH |
2192 | if (!helper_argv) { |
2193 | printk(KERN_WARNING "%s failed to allocate memory\n", | |
2194 | __func__); | |
a293980c | 2195 | goto fail_dropcount; |
350eaf79 | 2196 | } |
32321137 | 2197 | |
d5bf4c4f ON |
2198 | retval = call_usermodehelper_fns(helper_argv[0], helper_argv, |
2199 | NULL, UMH_WAIT_EXEC, umh_pipe_setup, | |
2200 | NULL, &cprm); | |
2201 | argv_free(helper_argv); | |
2202 | if (retval) { | |
d025c9db | 2203 | printk(KERN_INFO "Core dump to %s pipe failed\n", |
1b0d300b | 2204 | cn.corename); |
d5bf4c4f | 2205 | goto close_fail; |
d025c9db | 2206 | } |
c7135411 ON |
2207 | } else { |
2208 | struct inode *inode; | |
2209 | ||
2210 | if (cprm.limit < binfmt->min_coredump) | |
2211 | goto fail_unlock; | |
2212 | ||
1b0d300b | 2213 | cprm.file = filp_open(cn.corename, |
6d4df677 AD |
2214 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
2215 | 0600); | |
c7135411 ON |
2216 | if (IS_ERR(cprm.file)) |
2217 | goto fail_unlock; | |
1da177e4 | 2218 | |
c7135411 ON |
2219 | inode = cprm.file->f_path.dentry->d_inode; |
2220 | if (inode->i_nlink > 1) | |
2221 | goto close_fail; | |
2222 | if (d_unhashed(cprm.file->f_path.dentry)) | |
2223 | goto close_fail; | |
2224 | /* | |
2225 | * AK: actually i see no reason to not allow this for named | |
2226 | * pipes etc, but keep the previous behaviour for now. | |
2227 | */ | |
2228 | if (!S_ISREG(inode->i_mode)) | |
2229 | goto close_fail; | |
2230 | /* | |
2231 | * Dont allow local users get cute and trick others to coredump | |
2232 | * into their pre-created files. | |
2233 | */ | |
2234 | if (inode->i_uid != current_fsuid()) | |
2235 | goto close_fail; | |
2236 | if (!cprm.file->f_op || !cprm.file->f_op->write) | |
2237 | goto close_fail; | |
2238 | if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file)) | |
2239 | goto close_fail; | |
2240 | } | |
1da177e4 | 2241 | |
c7135411 | 2242 | retval = binfmt->core_dump(&cprm); |
1da177e4 LT |
2243 | if (retval) |
2244 | current->signal->group_exit_code |= 0x80; | |
d5bf4c4f | 2245 | |
61be228a | 2246 | if (ispipe && core_pipe_limit) |
f6151dfe | 2247 | wait_for_dump_helpers(cprm.file); |
d5bf4c4f ON |
2248 | close_fail: |
2249 | if (cprm.file) | |
2250 | filp_close(cprm.file, NULL); | |
a293980c | 2251 | fail_dropcount: |
d5bf4c4f | 2252 | if (ispipe) |
a293980c | 2253 | atomic_dec(&core_dump_count); |
1da177e4 | 2254 | fail_unlock: |
1b0d300b XF |
2255 | kfree(cn.corename); |
2256 | fail_corename: | |
5e43aef5 | 2257 | coredump_finish(mm); |
d84f4f99 | 2258 | revert_creds(old_cred); |
5e43aef5 | 2259 | fail_creds: |
d84f4f99 | 2260 | put_cred(cred); |
1da177e4 | 2261 | fail: |
8cd3ac3a | 2262 | return; |
1da177e4 | 2263 | } |
3aa0ce82 LT |
2264 | |
2265 | /* | |
2266 | * Core dumping helper functions. These are the only things you should | |
2267 | * do on a core-file: use only these functions to write out all the | |
2268 | * necessary info. | |
2269 | */ | |
2270 | int dump_write(struct file *file, const void *addr, int nr) | |
2271 | { | |
2272 | return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr; | |
2273 | } | |
8fd01d6c | 2274 | EXPORT_SYMBOL(dump_write); |
3aa0ce82 LT |
2275 | |
2276 | int dump_seek(struct file *file, loff_t off) | |
2277 | { | |
2278 | int ret = 1; | |
2279 | ||
2280 | if (file->f_op->llseek && file->f_op->llseek != no_llseek) { | |
2281 | if (file->f_op->llseek(file, off, SEEK_CUR) < 0) | |
2282 | return 0; | |
2283 | } else { | |
2284 | char *buf = (char *)get_zeroed_page(GFP_KERNEL); | |
2285 | ||
2286 | if (!buf) | |
2287 | return 0; | |
2288 | while (off > 0) { | |
2289 | unsigned long n = off; | |
2290 | ||
2291 | if (n > PAGE_SIZE) | |
2292 | n = PAGE_SIZE; | |
2293 | if (!dump_write(file, buf, n)) { | |
2294 | ret = 0; | |
2295 | break; | |
2296 | } | |
2297 | off -= n; | |
2298 | } | |
2299 | free_page((unsigned long)buf); | |
2300 | } | |
2301 | return ret; | |
2302 | } | |
8fd01d6c | 2303 | EXPORT_SYMBOL(dump_seek); |