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> |
43d2b113 KH |
62 | |
63 | #include <trace/events/task.h> | |
a6f76f23 | 64 | #include "internal.h" |
1da177e4 | 65 | |
4ff16c25 DS |
66 | #include <trace/events/sched.h> |
67 | ||
1da177e4 | 68 | int core_uses_pid; |
71ce92f3 | 69 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
a293980c | 70 | unsigned int core_pipe_limit; |
d6e71144 AC |
71 | int suid_dumpable = 0; |
72 | ||
1b0d300b XF |
73 | struct core_name { |
74 | char *corename; | |
75 | int used, size; | |
76 | }; | |
77 | static atomic_t call_count = ATOMIC_INIT(1); | |
78 | ||
1da177e4 LT |
79 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
80 | ||
e4dc1b14 | 81 | static LIST_HEAD(formats); |
1da177e4 LT |
82 | static DEFINE_RWLOCK(binfmt_lock); |
83 | ||
74641f58 | 84 | int __register_binfmt(struct linux_binfmt * fmt, int insert) |
1da177e4 | 85 | { |
1da177e4 LT |
86 | if (!fmt) |
87 | return -EINVAL; | |
1da177e4 | 88 | write_lock(&binfmt_lock); |
74641f58 IK |
89 | insert ? list_add(&fmt->lh, &formats) : |
90 | list_add_tail(&fmt->lh, &formats); | |
1da177e4 LT |
91 | write_unlock(&binfmt_lock); |
92 | return 0; | |
93 | } | |
94 | ||
74641f58 | 95 | EXPORT_SYMBOL(__register_binfmt); |
1da177e4 | 96 | |
f6b450d4 | 97 | void unregister_binfmt(struct linux_binfmt * fmt) |
1da177e4 | 98 | { |
1da177e4 | 99 | write_lock(&binfmt_lock); |
e4dc1b14 | 100 | list_del(&fmt->lh); |
1da177e4 | 101 | write_unlock(&binfmt_lock); |
1da177e4 LT |
102 | } |
103 | ||
104 | EXPORT_SYMBOL(unregister_binfmt); | |
105 | ||
106 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
107 | { | |
108 | module_put(fmt->module); | |
109 | } | |
110 | ||
111 | /* | |
112 | * Note that a shared library must be both readable and executable due to | |
113 | * security reasons. | |
114 | * | |
115 | * Also note that we take the address to load from from the file itself. | |
116 | */ | |
1e7bfb21 | 117 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
1da177e4 | 118 | { |
964bd183 | 119 | struct file *file; |
964bd183 AV |
120 | char *tmp = getname(library); |
121 | int error = PTR_ERR(tmp); | |
47c805dc AV |
122 | static const struct open_flags uselib_flags = { |
123 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
124 | .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, | |
125 | .intent = LOOKUP_OPEN | |
126 | }; | |
964bd183 | 127 | |
6e8341a1 AV |
128 | if (IS_ERR(tmp)) |
129 | goto out; | |
130 | ||
47c805dc | 131 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); |
6e8341a1 AV |
132 | putname(tmp); |
133 | error = PTR_ERR(file); | |
134 | if (IS_ERR(file)) | |
1da177e4 LT |
135 | goto out; |
136 | ||
137 | error = -EINVAL; | |
6e8341a1 | 138 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
1da177e4 LT |
139 | goto exit; |
140 | ||
30524472 | 141 | error = -EACCES; |
6e8341a1 | 142 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
1da177e4 LT |
143 | goto exit; |
144 | ||
2a12a9d7 | 145 | fsnotify_open(file); |
6110e3ab | 146 | |
1da177e4 LT |
147 | error = -ENOEXEC; |
148 | if(file->f_op) { | |
149 | struct linux_binfmt * fmt; | |
150 | ||
151 | read_lock(&binfmt_lock); | |
e4dc1b14 | 152 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
153 | if (!fmt->load_shlib) |
154 | continue; | |
155 | if (!try_module_get(fmt->module)) | |
156 | continue; | |
157 | read_unlock(&binfmt_lock); | |
158 | error = fmt->load_shlib(file); | |
159 | read_lock(&binfmt_lock); | |
160 | put_binfmt(fmt); | |
161 | if (error != -ENOEXEC) | |
162 | break; | |
163 | } | |
164 | read_unlock(&binfmt_lock); | |
165 | } | |
6e8341a1 | 166 | exit: |
1da177e4 LT |
167 | fput(file); |
168 | out: | |
169 | return error; | |
1da177e4 LT |
170 | } |
171 | ||
b6a2fea3 | 172 | #ifdef CONFIG_MMU |
ae6b585e ON |
173 | /* |
174 | * The nascent bprm->mm is not visible until exec_mmap() but it can | |
175 | * use a lot of memory, account these pages in current->mm temporary | |
176 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we | |
177 | * change the counter back via acct_arg_size(0). | |
178 | */ | |
0e028465 | 179 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
180 | { |
181 | struct mm_struct *mm = current->mm; | |
182 | long diff = (long)(pages - bprm->vma_pages); | |
183 | ||
184 | if (!mm || !diff) | |
185 | return; | |
186 | ||
187 | bprm->vma_pages = pages; | |
3c77f845 | 188 | add_mm_counter(mm, MM_ANONPAGES, diff); |
3c77f845 ON |
189 | } |
190 | ||
0e028465 | 191 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
192 | int write) |
193 | { | |
194 | struct page *page; | |
195 | int ret; | |
196 | ||
197 | #ifdef CONFIG_STACK_GROWSUP | |
198 | if (write) { | |
d05f3169 | 199 | ret = expand_downwards(bprm->vma, pos); |
b6a2fea3 OW |
200 | if (ret < 0) |
201 | return NULL; | |
202 | } | |
203 | #endif | |
204 | ret = get_user_pages(current, bprm->mm, pos, | |
205 | 1, write, 1, &page, NULL); | |
206 | if (ret <= 0) | |
207 | return NULL; | |
208 | ||
209 | if (write) { | |
b6a2fea3 | 210 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
a64e715f LT |
211 | struct rlimit *rlim; |
212 | ||
3c77f845 ON |
213 | acct_arg_size(bprm, size / PAGE_SIZE); |
214 | ||
a64e715f LT |
215 | /* |
216 | * We've historically supported up to 32 pages (ARG_MAX) | |
217 | * of argument strings even with small stacks | |
218 | */ | |
219 | if (size <= ARG_MAX) | |
220 | return page; | |
b6a2fea3 OW |
221 | |
222 | /* | |
223 | * Limit to 1/4-th the stack size for the argv+env strings. | |
224 | * This ensures that: | |
225 | * - the remaining binfmt code will not run out of stack space, | |
226 | * - the program will have a reasonable amount of stack left | |
227 | * to work from. | |
228 | */ | |
a64e715f | 229 | rlim = current->signal->rlim; |
d554ed89 | 230 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
b6a2fea3 OW |
231 | put_page(page); |
232 | return NULL; | |
233 | } | |
234 | } | |
235 | ||
236 | return page; | |
237 | } | |
238 | ||
239 | static void put_arg_page(struct page *page) | |
240 | { | |
241 | put_page(page); | |
242 | } | |
243 | ||
244 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
245 | { | |
246 | } | |
247 | ||
248 | static void free_arg_pages(struct linux_binprm *bprm) | |
249 | { | |
250 | } | |
251 | ||
252 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
253 | struct page *page) | |
254 | { | |
255 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); | |
256 | } | |
257 | ||
258 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
259 | { | |
eaccbfa5 | 260 | int err; |
b6a2fea3 OW |
261 | struct vm_area_struct *vma = NULL; |
262 | struct mm_struct *mm = bprm->mm; | |
263 | ||
264 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
265 | if (!vma) | |
eaccbfa5 | 266 | return -ENOMEM; |
b6a2fea3 OW |
267 | |
268 | down_write(&mm->mmap_sem); | |
269 | vma->vm_mm = mm; | |
270 | ||
271 | /* | |
272 | * Place the stack at the largest stack address the architecture | |
273 | * supports. Later, we'll move this to an appropriate place. We don't | |
274 | * use STACK_TOP because that can depend on attributes which aren't | |
275 | * configured yet. | |
276 | */ | |
aacb3d17 | 277 | BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
b6a2fea3 OW |
278 | vma->vm_end = STACK_TOP_MAX; |
279 | vma->vm_start = vma->vm_end - PAGE_SIZE; | |
a8bef8ff | 280 | vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
3ed75eb8 | 281 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
5beb4930 | 282 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
462e635e TO |
283 | |
284 | err = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1); | |
285 | if (err) | |
286 | goto err; | |
287 | ||
b6a2fea3 | 288 | err = insert_vm_struct(mm, vma); |
eaccbfa5 | 289 | if (err) |
b6a2fea3 | 290 | goto err; |
b6a2fea3 OW |
291 | |
292 | mm->stack_vm = mm->total_vm = 1; | |
293 | up_write(&mm->mmap_sem); | |
b6a2fea3 | 294 | bprm->p = vma->vm_end - sizeof(void *); |
b6a2fea3 | 295 | return 0; |
b6a2fea3 | 296 | err: |
eaccbfa5 LFC |
297 | up_write(&mm->mmap_sem); |
298 | bprm->vma = NULL; | |
299 | kmem_cache_free(vm_area_cachep, vma); | |
b6a2fea3 OW |
300 | return err; |
301 | } | |
302 | ||
303 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
304 | { | |
305 | return len <= MAX_ARG_STRLEN; | |
306 | } | |
307 | ||
308 | #else | |
309 | ||
0e028465 | 310 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
311 | { |
312 | } | |
313 | ||
0e028465 | 314 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
315 | int write) |
316 | { | |
317 | struct page *page; | |
318 | ||
319 | page = bprm->page[pos / PAGE_SIZE]; | |
320 | if (!page && write) { | |
321 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); | |
322 | if (!page) | |
323 | return NULL; | |
324 | bprm->page[pos / PAGE_SIZE] = page; | |
325 | } | |
326 | ||
327 | return page; | |
328 | } | |
329 | ||
330 | static void put_arg_page(struct page *page) | |
331 | { | |
332 | } | |
333 | ||
334 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
335 | { | |
336 | if (bprm->page[i]) { | |
337 | __free_page(bprm->page[i]); | |
338 | bprm->page[i] = NULL; | |
339 | } | |
340 | } | |
341 | ||
342 | static void free_arg_pages(struct linux_binprm *bprm) | |
343 | { | |
344 | int i; | |
345 | ||
346 | for (i = 0; i < MAX_ARG_PAGES; i++) | |
347 | free_arg_page(bprm, i); | |
348 | } | |
349 | ||
350 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
351 | struct page *page) | |
352 | { | |
353 | } | |
354 | ||
355 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
356 | { | |
357 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); | |
358 | return 0; | |
359 | } | |
360 | ||
361 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
362 | { | |
363 | return len <= bprm->p; | |
364 | } | |
365 | ||
366 | #endif /* CONFIG_MMU */ | |
367 | ||
368 | /* | |
369 | * Create a new mm_struct and populate it with a temporary stack | |
370 | * vm_area_struct. We don't have enough context at this point to set the stack | |
371 | * flags, permissions, and offset, so we use temporary values. We'll update | |
372 | * them later in setup_arg_pages(). | |
373 | */ | |
374 | int bprm_mm_init(struct linux_binprm *bprm) | |
375 | { | |
376 | int err; | |
377 | struct mm_struct *mm = NULL; | |
378 | ||
379 | bprm->mm = mm = mm_alloc(); | |
380 | err = -ENOMEM; | |
381 | if (!mm) | |
382 | goto err; | |
383 | ||
384 | err = init_new_context(current, mm); | |
385 | if (err) | |
386 | goto err; | |
387 | ||
388 | err = __bprm_mm_init(bprm); | |
389 | if (err) | |
390 | goto err; | |
391 | ||
392 | return 0; | |
393 | ||
394 | err: | |
395 | if (mm) { | |
396 | bprm->mm = NULL; | |
397 | mmdrop(mm); | |
398 | } | |
399 | ||
400 | return err; | |
401 | } | |
402 | ||
ba2d0162 | 403 | struct user_arg_ptr { |
0e028465 ON |
404 | #ifdef CONFIG_COMPAT |
405 | bool is_compat; | |
406 | #endif | |
407 | union { | |
408 | const char __user *const __user *native; | |
409 | #ifdef CONFIG_COMPAT | |
410 | compat_uptr_t __user *compat; | |
411 | #endif | |
412 | } ptr; | |
ba2d0162 ON |
413 | }; |
414 | ||
415 | static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr) | |
1d1dbf81 | 416 | { |
0e028465 ON |
417 | const char __user *native; |
418 | ||
419 | #ifdef CONFIG_COMPAT | |
420 | if (unlikely(argv.is_compat)) { | |
421 | compat_uptr_t compat; | |
422 | ||
423 | if (get_user(compat, argv.ptr.compat + nr)) | |
424 | return ERR_PTR(-EFAULT); | |
1d1dbf81 | 425 | |
0e028465 ON |
426 | return compat_ptr(compat); |
427 | } | |
428 | #endif | |
429 | ||
430 | if (get_user(native, argv.ptr.native + nr)) | |
1d1dbf81 ON |
431 | return ERR_PTR(-EFAULT); |
432 | ||
0e028465 | 433 | return native; |
1d1dbf81 ON |
434 | } |
435 | ||
1da177e4 LT |
436 | /* |
437 | * count() counts the number of strings in array ARGV. | |
438 | */ | |
ba2d0162 | 439 | static int count(struct user_arg_ptr argv, int max) |
1da177e4 LT |
440 | { |
441 | int i = 0; | |
442 | ||
0e028465 | 443 | if (argv.ptr.native != NULL) { |
1da177e4 | 444 | for (;;) { |
1d1dbf81 | 445 | const char __user *p = get_user_arg_ptr(argv, i); |
1da177e4 | 446 | |
1da177e4 LT |
447 | if (!p) |
448 | break; | |
1d1dbf81 ON |
449 | |
450 | if (IS_ERR(p)) | |
451 | return -EFAULT; | |
452 | ||
362e6663 | 453 | if (i++ >= max) |
1da177e4 | 454 | return -E2BIG; |
9aea5a65 RM |
455 | |
456 | if (fatal_signal_pending(current)) | |
457 | return -ERESTARTNOHAND; | |
1da177e4 LT |
458 | cond_resched(); |
459 | } | |
460 | } | |
461 | return i; | |
462 | } | |
463 | ||
464 | /* | |
b6a2fea3 OW |
465 | * 'copy_strings()' copies argument/environment strings from the old |
466 | * processes's memory to the new process's stack. The call to get_user_pages() | |
467 | * ensures the destination page is created and not swapped out. | |
1da177e4 | 468 | */ |
ba2d0162 | 469 | static int copy_strings(int argc, struct user_arg_ptr argv, |
75c96f85 | 470 | struct linux_binprm *bprm) |
1da177e4 LT |
471 | { |
472 | struct page *kmapped_page = NULL; | |
473 | char *kaddr = NULL; | |
b6a2fea3 | 474 | unsigned long kpos = 0; |
1da177e4 LT |
475 | int ret; |
476 | ||
477 | while (argc-- > 0) { | |
d7627467 | 478 | const char __user *str; |
1da177e4 LT |
479 | int len; |
480 | unsigned long pos; | |
481 | ||
1d1dbf81 ON |
482 | ret = -EFAULT; |
483 | str = get_user_arg_ptr(argv, argc); | |
484 | if (IS_ERR(str)) | |
1da177e4 | 485 | goto out; |
1da177e4 | 486 | |
1d1dbf81 ON |
487 | len = strnlen_user(str, MAX_ARG_STRLEN); |
488 | if (!len) | |
489 | goto out; | |
490 | ||
491 | ret = -E2BIG; | |
492 | if (!valid_arg_len(bprm, len)) | |
1da177e4 | 493 | goto out; |
1da177e4 | 494 | |
b6a2fea3 | 495 | /* We're going to work our way backwords. */ |
1da177e4 | 496 | pos = bprm->p; |
b6a2fea3 OW |
497 | str += len; |
498 | bprm->p -= len; | |
1da177e4 LT |
499 | |
500 | while (len > 0) { | |
1da177e4 | 501 | int offset, bytes_to_copy; |
1da177e4 | 502 | |
9aea5a65 RM |
503 | if (fatal_signal_pending(current)) { |
504 | ret = -ERESTARTNOHAND; | |
505 | goto out; | |
506 | } | |
7993bc1f RM |
507 | cond_resched(); |
508 | ||
1da177e4 | 509 | offset = pos % PAGE_SIZE; |
b6a2fea3 OW |
510 | if (offset == 0) |
511 | offset = PAGE_SIZE; | |
512 | ||
513 | bytes_to_copy = offset; | |
514 | if (bytes_to_copy > len) | |
515 | bytes_to_copy = len; | |
516 | ||
517 | offset -= bytes_to_copy; | |
518 | pos -= bytes_to_copy; | |
519 | str -= bytes_to_copy; | |
520 | len -= bytes_to_copy; | |
521 | ||
522 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { | |
523 | struct page *page; | |
524 | ||
525 | page = get_arg_page(bprm, pos, 1); | |
1da177e4 | 526 | if (!page) { |
b6a2fea3 | 527 | ret = -E2BIG; |
1da177e4 LT |
528 | goto out; |
529 | } | |
1da177e4 | 530 | |
b6a2fea3 OW |
531 | if (kmapped_page) { |
532 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 533 | kunmap(kmapped_page); |
b6a2fea3 OW |
534 | put_arg_page(kmapped_page); |
535 | } | |
1da177e4 LT |
536 | kmapped_page = page; |
537 | kaddr = kmap(kmapped_page); | |
b6a2fea3 OW |
538 | kpos = pos & PAGE_MASK; |
539 | flush_arg_page(bprm, kpos, kmapped_page); | |
1da177e4 | 540 | } |
b6a2fea3 | 541 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
1da177e4 LT |
542 | ret = -EFAULT; |
543 | goto out; | |
544 | } | |
1da177e4 LT |
545 | } |
546 | } | |
547 | ret = 0; | |
548 | out: | |
b6a2fea3 OW |
549 | if (kmapped_page) { |
550 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 551 | kunmap(kmapped_page); |
b6a2fea3 OW |
552 | put_arg_page(kmapped_page); |
553 | } | |
1da177e4 LT |
554 | return ret; |
555 | } | |
556 | ||
557 | /* | |
558 | * Like copy_strings, but get argv and its values from kernel memory. | |
559 | */ | |
ba2d0162 | 560 | int copy_strings_kernel(int argc, const char *const *__argv, |
d7627467 | 561 | struct linux_binprm *bprm) |
1da177e4 LT |
562 | { |
563 | int r; | |
564 | mm_segment_t oldfs = get_fs(); | |
ba2d0162 | 565 | struct user_arg_ptr argv = { |
0e028465 | 566 | .ptr.native = (const char __user *const __user *)__argv, |
ba2d0162 ON |
567 | }; |
568 | ||
1da177e4 | 569 | set_fs(KERNEL_DS); |
ba2d0162 | 570 | r = copy_strings(argc, argv, bprm); |
1da177e4 | 571 | set_fs(oldfs); |
ba2d0162 | 572 | |
1da177e4 LT |
573 | return r; |
574 | } | |
1da177e4 LT |
575 | EXPORT_SYMBOL(copy_strings_kernel); |
576 | ||
577 | #ifdef CONFIG_MMU | |
b6a2fea3 | 578 | |
1da177e4 | 579 | /* |
b6a2fea3 OW |
580 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
581 | * the binfmt code determines where the new stack should reside, we shift it to | |
582 | * its final location. The process proceeds as follows: | |
1da177e4 | 583 | * |
b6a2fea3 OW |
584 | * 1) Use shift to calculate the new vma endpoints. |
585 | * 2) Extend vma to cover both the old and new ranges. This ensures the | |
586 | * arguments passed to subsequent functions are consistent. | |
587 | * 3) Move vma's page tables to the new range. | |
588 | * 4) Free up any cleared pgd range. | |
589 | * 5) Shrink the vma to cover only the new range. | |
1da177e4 | 590 | */ |
b6a2fea3 | 591 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
1da177e4 LT |
592 | { |
593 | struct mm_struct *mm = vma->vm_mm; | |
b6a2fea3 OW |
594 | unsigned long old_start = vma->vm_start; |
595 | unsigned long old_end = vma->vm_end; | |
596 | unsigned long length = old_end - old_start; | |
597 | unsigned long new_start = old_start - shift; | |
598 | unsigned long new_end = old_end - shift; | |
d16dfc55 | 599 | struct mmu_gather tlb; |
1da177e4 | 600 | |
b6a2fea3 | 601 | BUG_ON(new_start > new_end); |
1da177e4 | 602 | |
b6a2fea3 OW |
603 | /* |
604 | * ensure there are no vmas between where we want to go | |
605 | * and where we are | |
606 | */ | |
607 | if (vma != find_vma(mm, new_start)) | |
608 | return -EFAULT; | |
609 | ||
610 | /* | |
611 | * cover the whole range: [new_start, old_end) | |
612 | */ | |
5beb4930 RR |
613 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
614 | return -ENOMEM; | |
b6a2fea3 OW |
615 | |
616 | /* | |
617 | * move the page tables downwards, on failure we rely on | |
618 | * process cleanup to remove whatever mess we made. | |
619 | */ | |
620 | if (length != move_page_tables(vma, old_start, | |
621 | vma, new_start, length)) | |
622 | return -ENOMEM; | |
623 | ||
624 | lru_add_drain(); | |
d16dfc55 | 625 | tlb_gather_mmu(&tlb, mm, 0); |
b6a2fea3 OW |
626 | if (new_end > old_start) { |
627 | /* | |
628 | * when the old and new regions overlap clear from new_end. | |
629 | */ | |
d16dfc55 | 630 | free_pgd_range(&tlb, new_end, old_end, new_end, |
b6a2fea3 OW |
631 | vma->vm_next ? vma->vm_next->vm_start : 0); |
632 | } else { | |
633 | /* | |
634 | * otherwise, clean from old_start; this is done to not touch | |
635 | * the address space in [new_end, old_start) some architectures | |
636 | * have constraints on va-space that make this illegal (IA64) - | |
637 | * for the others its just a little faster. | |
638 | */ | |
d16dfc55 | 639 | free_pgd_range(&tlb, old_start, old_end, new_end, |
b6a2fea3 | 640 | vma->vm_next ? vma->vm_next->vm_start : 0); |
1da177e4 | 641 | } |
d16dfc55 | 642 | tlb_finish_mmu(&tlb, new_end, old_end); |
b6a2fea3 OW |
643 | |
644 | /* | |
5beb4930 | 645 | * Shrink the vma to just the new range. Always succeeds. |
b6a2fea3 OW |
646 | */ |
647 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); | |
648 | ||
649 | return 0; | |
1da177e4 LT |
650 | } |
651 | ||
b6a2fea3 OW |
652 | /* |
653 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, | |
654 | * the stack is optionally relocated, and some extra space is added. | |
655 | */ | |
1da177e4 LT |
656 | int setup_arg_pages(struct linux_binprm *bprm, |
657 | unsigned long stack_top, | |
658 | int executable_stack) | |
659 | { | |
b6a2fea3 OW |
660 | unsigned long ret; |
661 | unsigned long stack_shift; | |
1da177e4 | 662 | struct mm_struct *mm = current->mm; |
b6a2fea3 OW |
663 | struct vm_area_struct *vma = bprm->vma; |
664 | struct vm_area_struct *prev = NULL; | |
665 | unsigned long vm_flags; | |
666 | unsigned long stack_base; | |
803bf5ec MN |
667 | unsigned long stack_size; |
668 | unsigned long stack_expand; | |
669 | unsigned long rlim_stack; | |
1da177e4 LT |
670 | |
671 | #ifdef CONFIG_STACK_GROWSUP | |
1da177e4 | 672 | /* Limit stack size to 1GB */ |
d554ed89 | 673 | stack_base = rlimit_max(RLIMIT_STACK); |
1da177e4 LT |
674 | if (stack_base > (1 << 30)) |
675 | stack_base = 1 << 30; | |
1da177e4 | 676 | |
b6a2fea3 OW |
677 | /* Make sure we didn't let the argument array grow too large. */ |
678 | if (vma->vm_end - vma->vm_start > stack_base) | |
679 | return -ENOMEM; | |
1da177e4 | 680 | |
b6a2fea3 | 681 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
1da177e4 | 682 | |
b6a2fea3 OW |
683 | stack_shift = vma->vm_start - stack_base; |
684 | mm->arg_start = bprm->p - stack_shift; | |
685 | bprm->p = vma->vm_end - stack_shift; | |
1da177e4 | 686 | #else |
b6a2fea3 OW |
687 | stack_top = arch_align_stack(stack_top); |
688 | stack_top = PAGE_ALIGN(stack_top); | |
1b528181 RM |
689 | |
690 | if (unlikely(stack_top < mmap_min_addr) || | |
691 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) | |
692 | return -ENOMEM; | |
693 | ||
b6a2fea3 OW |
694 | stack_shift = vma->vm_end - stack_top; |
695 | ||
696 | bprm->p -= stack_shift; | |
1da177e4 | 697 | mm->arg_start = bprm->p; |
1da177e4 LT |
698 | #endif |
699 | ||
1da177e4 | 700 | if (bprm->loader) |
b6a2fea3 OW |
701 | bprm->loader -= stack_shift; |
702 | bprm->exec -= stack_shift; | |
1da177e4 | 703 | |
1da177e4 | 704 | down_write(&mm->mmap_sem); |
96a8e13e | 705 | vm_flags = VM_STACK_FLAGS; |
b6a2fea3 OW |
706 | |
707 | /* | |
708 | * Adjust stack execute permissions; explicitly enable for | |
709 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone | |
710 | * (arch default) otherwise. | |
711 | */ | |
712 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
713 | vm_flags |= VM_EXEC; | |
714 | else if (executable_stack == EXSTACK_DISABLE_X) | |
715 | vm_flags &= ~VM_EXEC; | |
716 | vm_flags |= mm->def_flags; | |
a8bef8ff | 717 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
b6a2fea3 OW |
718 | |
719 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, | |
720 | vm_flags); | |
721 | if (ret) | |
722 | goto out_unlock; | |
723 | BUG_ON(prev != vma); | |
724 | ||
725 | /* Move stack pages down in memory. */ | |
726 | if (stack_shift) { | |
727 | ret = shift_arg_pages(vma, stack_shift); | |
fc63cf23 AB |
728 | if (ret) |
729 | goto out_unlock; | |
1da177e4 LT |
730 | } |
731 | ||
a8bef8ff MG |
732 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
733 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; | |
734 | ||
5ef097dd | 735 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
803bf5ec MN |
736 | stack_size = vma->vm_end - vma->vm_start; |
737 | /* | |
738 | * Align this down to a page boundary as expand_stack | |
739 | * will align it up. | |
740 | */ | |
741 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; | |
b6a2fea3 | 742 | #ifdef CONFIG_STACK_GROWSUP |
803bf5ec MN |
743 | if (stack_size + stack_expand > rlim_stack) |
744 | stack_base = vma->vm_start + rlim_stack; | |
745 | else | |
746 | stack_base = vma->vm_end + stack_expand; | |
b6a2fea3 | 747 | #else |
803bf5ec MN |
748 | if (stack_size + stack_expand > rlim_stack) |
749 | stack_base = vma->vm_end - rlim_stack; | |
750 | else | |
751 | stack_base = vma->vm_start - stack_expand; | |
b6a2fea3 | 752 | #endif |
3af9e859 | 753 | current->mm->start_stack = bprm->p; |
b6a2fea3 OW |
754 | ret = expand_stack(vma, stack_base); |
755 | if (ret) | |
756 | ret = -EFAULT; | |
757 | ||
758 | out_unlock: | |
1da177e4 | 759 | up_write(&mm->mmap_sem); |
fc63cf23 | 760 | return ret; |
1da177e4 | 761 | } |
1da177e4 LT |
762 | EXPORT_SYMBOL(setup_arg_pages); |
763 | ||
1da177e4 LT |
764 | #endif /* CONFIG_MMU */ |
765 | ||
766 | struct file *open_exec(const char *name) | |
767 | { | |
1da177e4 | 768 | struct file *file; |
e56b6a5d | 769 | int err; |
47c805dc AV |
770 | static const struct open_flags open_exec_flags = { |
771 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
772 | .acc_mode = MAY_EXEC | MAY_OPEN, | |
773 | .intent = LOOKUP_OPEN | |
774 | }; | |
1da177e4 | 775 | |
47c805dc | 776 | file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); |
6e8341a1 | 777 | if (IS_ERR(file)) |
e56b6a5d CH |
778 | goto out; |
779 | ||
780 | err = -EACCES; | |
6e8341a1 AV |
781 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
782 | goto exit; | |
e56b6a5d | 783 | |
6e8341a1 AV |
784 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
785 | goto exit; | |
e56b6a5d | 786 | |
2a12a9d7 | 787 | fsnotify_open(file); |
6110e3ab | 788 | |
e56b6a5d | 789 | err = deny_write_access(file); |
6e8341a1 AV |
790 | if (err) |
791 | goto exit; | |
1da177e4 | 792 | |
6e8341a1 | 793 | out: |
e56b6a5d CH |
794 | return file; |
795 | ||
6e8341a1 AV |
796 | exit: |
797 | fput(file); | |
e56b6a5d CH |
798 | return ERR_PTR(err); |
799 | } | |
1da177e4 LT |
800 | EXPORT_SYMBOL(open_exec); |
801 | ||
6777d773 MZ |
802 | int kernel_read(struct file *file, loff_t offset, |
803 | char *addr, unsigned long count) | |
1da177e4 LT |
804 | { |
805 | mm_segment_t old_fs; | |
806 | loff_t pos = offset; | |
807 | int result; | |
808 | ||
809 | old_fs = get_fs(); | |
810 | set_fs(get_ds()); | |
811 | /* The cast to a user pointer is valid due to the set_fs() */ | |
812 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
813 | set_fs(old_fs); | |
814 | return result; | |
815 | } | |
816 | ||
817 | EXPORT_SYMBOL(kernel_read); | |
818 | ||
819 | static int exec_mmap(struct mm_struct *mm) | |
820 | { | |
821 | struct task_struct *tsk; | |
822 | struct mm_struct * old_mm, *active_mm; | |
823 | ||
824 | /* Notify parent that we're no longer interested in the old VM */ | |
825 | tsk = current; | |
826 | old_mm = current->mm; | |
34e55232 | 827 | sync_mm_rss(tsk, old_mm); |
1da177e4 LT |
828 | mm_release(tsk, old_mm); |
829 | ||
830 | if (old_mm) { | |
831 | /* | |
832 | * Make sure that if there is a core dump in progress | |
833 | * for the old mm, we get out and die instead of going | |
834 | * through with the exec. We must hold mmap_sem around | |
999d9fc1 | 835 | * checking core_state and changing tsk->mm. |
1da177e4 LT |
836 | */ |
837 | down_read(&old_mm->mmap_sem); | |
999d9fc1 | 838 | if (unlikely(old_mm->core_state)) { |
1da177e4 LT |
839 | up_read(&old_mm->mmap_sem); |
840 | return -EINTR; | |
841 | } | |
842 | } | |
843 | task_lock(tsk); | |
844 | active_mm = tsk->active_mm; | |
845 | tsk->mm = mm; | |
846 | tsk->active_mm = mm; | |
847 | activate_mm(active_mm, mm); | |
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); |
701085b2 | 853 | setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm); |
31a78f23 | 854 | mm_update_next_owner(old_mm); |
1da177e4 LT |
855 | mmput(old_mm); |
856 | return 0; | |
857 | } | |
858 | mmdrop(active_mm); | |
859 | return 0; | |
860 | } | |
861 | ||
862 | /* | |
863 | * This function makes sure the current process has its own signal table, | |
864 | * so that flush_signal_handlers can later reset the handlers without | |
865 | * disturbing other processes. (Other processes might share the signal | |
866 | * table via the CLONE_SIGHAND option to clone().) | |
867 | */ | |
858119e1 | 868 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
869 | { |
870 | struct signal_struct *sig = tsk->signal; | |
b2c903b8 | 871 | struct sighand_struct *oldsighand = tsk->sighand; |
1da177e4 | 872 | spinlock_t *lock = &oldsighand->siglock; |
1da177e4 | 873 | |
aafe6c2a | 874 | if (thread_group_empty(tsk)) |
1da177e4 LT |
875 | goto no_thread_group; |
876 | ||
877 | /* | |
878 | * Kill all other threads in the thread group. | |
1da177e4 | 879 | */ |
1da177e4 | 880 | spin_lock_irq(lock); |
ed5d2cac | 881 | if (signal_group_exit(sig)) { |
1da177e4 LT |
882 | /* |
883 | * Another group action in progress, just | |
884 | * return so that the signal is processed. | |
885 | */ | |
886 | spin_unlock_irq(lock); | |
1da177e4 LT |
887 | return -EAGAIN; |
888 | } | |
d344193a | 889 | |
ed5d2cac | 890 | sig->group_exit_task = tsk; |
d344193a ON |
891 | sig->notify_count = zap_other_threads(tsk); |
892 | if (!thread_group_leader(tsk)) | |
893 | sig->notify_count--; | |
1da177e4 | 894 | |
d344193a | 895 | while (sig->notify_count) { |
1da177e4 LT |
896 | __set_current_state(TASK_UNINTERRUPTIBLE); |
897 | spin_unlock_irq(lock); | |
898 | schedule(); | |
899 | spin_lock_irq(lock); | |
900 | } | |
1da177e4 LT |
901 | spin_unlock_irq(lock); |
902 | ||
903 | /* | |
904 | * At this point all other threads have exited, all we have to | |
905 | * do is to wait for the thread group leader to become inactive, | |
906 | * and to assume its PID: | |
907 | */ | |
aafe6c2a | 908 | if (!thread_group_leader(tsk)) { |
8187926b | 909 | struct task_struct *leader = tsk->group_leader; |
6db840fa | 910 | |
2800d8d1 | 911 | sig->notify_count = -1; /* for exit_notify() */ |
6db840fa ON |
912 | for (;;) { |
913 | write_lock_irq(&tasklist_lock); | |
914 | if (likely(leader->exit_state)) | |
915 | break; | |
916 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
917 | write_unlock_irq(&tasklist_lock); | |
918 | schedule(); | |
919 | } | |
1da177e4 | 920 | |
f5e90281 RM |
921 | /* |
922 | * The only record we have of the real-time age of a | |
923 | * process, regardless of execs it's done, is start_time. | |
924 | * All the past CPU time is accumulated in signal_struct | |
925 | * from sister threads now dead. But in this non-leader | |
926 | * exec, nothing survives from the original leader thread, | |
927 | * whose birth marks the true age of this process now. | |
928 | * When we take on its identity by switching to its PID, we | |
929 | * also take its birthdate (always earlier than our own). | |
930 | */ | |
aafe6c2a | 931 | tsk->start_time = leader->start_time; |
f5e90281 | 932 | |
bac0abd6 PE |
933 | BUG_ON(!same_thread_group(leader, tsk)); |
934 | BUG_ON(has_group_leader_pid(tsk)); | |
1da177e4 LT |
935 | /* |
936 | * An exec() starts a new thread group with the | |
937 | * TGID of the previous thread group. Rehash the | |
938 | * two threads with a switched PID, and release | |
939 | * the former thread group leader: | |
940 | */ | |
d73d6529 EB |
941 | |
942 | /* Become a process group leader with the old leader's pid. | |
c18258c6 EB |
943 | * The old leader becomes a thread of the this thread group. |
944 | * Note: The old leader also uses this pid until release_task | |
d73d6529 EB |
945 | * is called. Odd but simple and correct. |
946 | */ | |
aafe6c2a EB |
947 | detach_pid(tsk, PIDTYPE_PID); |
948 | tsk->pid = leader->pid; | |
3743ca05 | 949 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
aafe6c2a EB |
950 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
951 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
9cd80bbb | 952 | |
aafe6c2a | 953 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
9cd80bbb | 954 | list_replace_init(&leader->sibling, &tsk->sibling); |
1da177e4 | 955 | |
aafe6c2a EB |
956 | tsk->group_leader = tsk; |
957 | leader->group_leader = tsk; | |
de12a787 | 958 | |
aafe6c2a | 959 | tsk->exit_signal = SIGCHLD; |
087806b1 | 960 | leader->exit_signal = -1; |
962b564c ON |
961 | |
962 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
963 | leader->exit_state = EXIT_DEAD; | |
eac1b5e5 ON |
964 | |
965 | /* | |
966 | * We are going to release_task()->ptrace_unlink() silently, | |
967 | * the tracer can sleep in do_wait(). EXIT_DEAD guarantees | |
968 | * the tracer wont't block again waiting for this thread. | |
969 | */ | |
970 | if (unlikely(leader->ptrace)) | |
971 | __wake_up_parent(leader, leader->parent); | |
1da177e4 | 972 | write_unlock_irq(&tasklist_lock); |
8187926b ON |
973 | |
974 | release_task(leader); | |
ed5d2cac | 975 | } |
1da177e4 | 976 | |
6db840fa ON |
977 | sig->group_exit_task = NULL; |
978 | sig->notify_count = 0; | |
1da177e4 LT |
979 | |
980 | no_thread_group: | |
e6368253 ON |
981 | /* we have changed execution domain */ |
982 | tsk->exit_signal = SIGCHLD; | |
983 | ||
1da177e4 | 984 | exit_itimers(sig); |
cbaffba1 | 985 | flush_itimer_signals(); |
329f7dba | 986 | |
b2c903b8 ON |
987 | if (atomic_read(&oldsighand->count) != 1) { |
988 | struct sighand_struct *newsighand; | |
1da177e4 | 989 | /* |
b2c903b8 ON |
990 | * This ->sighand is shared with the CLONE_SIGHAND |
991 | * but not CLONE_THREAD task, switch to the new one. | |
1da177e4 | 992 | */ |
b2c903b8 ON |
993 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
994 | if (!newsighand) | |
995 | return -ENOMEM; | |
996 | ||
1da177e4 LT |
997 | atomic_set(&newsighand->count, 1); |
998 | memcpy(newsighand->action, oldsighand->action, | |
999 | sizeof(newsighand->action)); | |
1000 | ||
1001 | write_lock_irq(&tasklist_lock); | |
1002 | spin_lock(&oldsighand->siglock); | |
aafe6c2a | 1003 | rcu_assign_pointer(tsk->sighand, newsighand); |
1da177e4 LT |
1004 | spin_unlock(&oldsighand->siglock); |
1005 | write_unlock_irq(&tasklist_lock); | |
1006 | ||
fba2afaa | 1007 | __cleanup_sighand(oldsighand); |
1da177e4 LT |
1008 | } |
1009 | ||
aafe6c2a | 1010 | BUG_ON(!thread_group_leader(tsk)); |
1da177e4 LT |
1011 | return 0; |
1012 | } | |
0840a90d | 1013 | |
1da177e4 LT |
1014 | /* |
1015 | * These functions flushes out all traces of the currently running executable | |
1016 | * so that a new one can be started | |
1017 | */ | |
858119e1 | 1018 | static void flush_old_files(struct files_struct * files) |
1da177e4 LT |
1019 | { |
1020 | long j = -1; | |
badf1662 | 1021 | struct fdtable *fdt; |
1da177e4 LT |
1022 | |
1023 | spin_lock(&files->file_lock); | |
1024 | for (;;) { | |
1025 | unsigned long set, i; | |
1026 | ||
1027 | j++; | |
1028 | i = j * __NFDBITS; | |
badf1662 | 1029 | fdt = files_fdtable(files); |
bbea9f69 | 1030 | if (i >= fdt->max_fds) |
1da177e4 | 1031 | break; |
badf1662 | 1032 | set = fdt->close_on_exec->fds_bits[j]; |
1da177e4 LT |
1033 | if (!set) |
1034 | continue; | |
badf1662 | 1035 | fdt->close_on_exec->fds_bits[j] = 0; |
1da177e4 LT |
1036 | spin_unlock(&files->file_lock); |
1037 | for ( ; set ; i++,set >>= 1) { | |
1038 | if (set & 1) { | |
1039 | sys_close(i); | |
1040 | } | |
1041 | } | |
1042 | spin_lock(&files->file_lock); | |
1043 | ||
1044 | } | |
1045 | spin_unlock(&files->file_lock); | |
1046 | } | |
1047 | ||
59714d65 | 1048 | char *get_task_comm(char *buf, struct task_struct *tsk) |
1da177e4 LT |
1049 | { |
1050 | /* buf must be at least sizeof(tsk->comm) in size */ | |
1051 | task_lock(tsk); | |
1052 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
1053 | task_unlock(tsk); | |
59714d65 | 1054 | return buf; |
1da177e4 | 1055 | } |
7d74f492 | 1056 | EXPORT_SYMBOL_GPL(get_task_comm); |
1da177e4 LT |
1057 | |
1058 | void set_task_comm(struct task_struct *tsk, char *buf) | |
1059 | { | |
1060 | task_lock(tsk); | |
4614a696 | 1061 | |
43d2b113 KH |
1062 | trace_task_rename(tsk, buf); |
1063 | ||
4614a696 | 1064 | /* |
1065 | * Threads may access current->comm without holding | |
1066 | * the task lock, so write the string carefully. | |
1067 | * Readers without a lock may see incomplete new | |
1068 | * names but are safe from non-terminating string reads. | |
1069 | */ | |
1070 | memset(tsk->comm, 0, TASK_COMM_LEN); | |
1071 | wmb(); | |
1da177e4 LT |
1072 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
1073 | task_unlock(tsk); | |
cdd6c482 | 1074 | perf_event_comm(tsk); |
1da177e4 LT |
1075 | } |
1076 | ||
96e02d15 HC |
1077 | static void filename_to_taskname(char *tcomm, const char *fn, unsigned int len) |
1078 | { | |
1079 | int i, ch; | |
1080 | ||
1081 | /* Copies the binary name from after last slash */ | |
1082 | for (i = 0; (ch = *(fn++)) != '\0';) { | |
1083 | if (ch == '/') | |
1084 | i = 0; /* overwrite what we wrote */ | |
1085 | else | |
1086 | if (i < len - 1) | |
1087 | tcomm[i++] = ch; | |
1088 | } | |
1089 | tcomm[i] = '\0'; | |
1090 | } | |
1091 | ||
1da177e4 LT |
1092 | int flush_old_exec(struct linux_binprm * bprm) |
1093 | { | |
221af7f8 | 1094 | int retval; |
1da177e4 LT |
1095 | |
1096 | /* | |
1097 | * Make sure we have a private signal table and that | |
1098 | * we are unassociated from the previous thread group. | |
1099 | */ | |
1100 | retval = de_thread(current); | |
1101 | if (retval) | |
1102 | goto out; | |
1103 | ||
925d1c40 MH |
1104 | set_mm_exe_file(bprm->mm, bprm->file); |
1105 | ||
96e02d15 | 1106 | filename_to_taskname(bprm->tcomm, bprm->filename, sizeof(bprm->tcomm)); |
1da177e4 LT |
1107 | /* |
1108 | * Release all of the old mmap stuff | |
1109 | */ | |
3c77f845 | 1110 | acct_arg_size(bprm, 0); |
1da177e4 LT |
1111 | retval = exec_mmap(bprm->mm); |
1112 | if (retval) | |
fd8328be | 1113 | goto out; |
1da177e4 LT |
1114 | |
1115 | bprm->mm = NULL; /* We're using it now */ | |
7ab02af4 | 1116 | |
dac853ae | 1117 | set_fs(USER_DS); |
98391cf4 | 1118 | current->flags &= ~(PF_RANDOMIZE | PF_KTHREAD); |
7ab02af4 LT |
1119 | flush_thread(); |
1120 | current->personality &= ~bprm->per_clear; | |
1121 | ||
221af7f8 LT |
1122 | return 0; |
1123 | ||
1124 | out: | |
1125 | return retval; | |
1126 | } | |
1127 | EXPORT_SYMBOL(flush_old_exec); | |
1128 | ||
1b5d783c AV |
1129 | void would_dump(struct linux_binprm *bprm, struct file *file) |
1130 | { | |
1131 | if (inode_permission(file->f_path.dentry->d_inode, MAY_READ) < 0) | |
1132 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; | |
1133 | } | |
1134 | EXPORT_SYMBOL(would_dump); | |
1135 | ||
221af7f8 LT |
1136 | void setup_new_exec(struct linux_binprm * bprm) |
1137 | { | |
221af7f8 | 1138 | arch_pick_mmap_layout(current->mm); |
1da177e4 LT |
1139 | |
1140 | /* This is the point of no return */ | |
1da177e4 LT |
1141 | current->sas_ss_sp = current->sas_ss_size = 0; |
1142 | ||
da9592ed | 1143 | if (current_euid() == current_uid() && current_egid() == current_gid()) |
6c5d5238 | 1144 | set_dumpable(current->mm, 1); |
d6e71144 | 1145 | else |
6c5d5238 | 1146 | set_dumpable(current->mm, suid_dumpable); |
d6e71144 | 1147 | |
96e02d15 | 1148 | set_task_comm(current, bprm->tcomm); |
1da177e4 | 1149 | |
0551fbd2 BH |
1150 | /* Set the new mm task size. We have to do that late because it may |
1151 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
1152 | * some architectures like powerpc | |
1153 | */ | |
1154 | current->mm->task_size = TASK_SIZE; | |
1155 | ||
a6f76f23 DH |
1156 | /* install the new credentials */ |
1157 | if (bprm->cred->uid != current_euid() || | |
1158 | bprm->cred->gid != current_egid()) { | |
d2d56c5f | 1159 | current->pdeath_signal = 0; |
1b5d783c AV |
1160 | } else { |
1161 | would_dump(bprm, bprm->file); | |
1162 | if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) | |
1163 | set_dumpable(current->mm, suid_dumpable); | |
1da177e4 LT |
1164 | } |
1165 | ||
f65cb45c IM |
1166 | /* |
1167 | * Flush performance counters when crossing a | |
1168 | * security domain: | |
1169 | */ | |
1170 | if (!get_dumpable(current->mm)) | |
cdd6c482 | 1171 | perf_event_exit_task(current); |
f65cb45c | 1172 | |
1da177e4 LT |
1173 | /* An exec changes our domain. We are no longer part of the thread |
1174 | group */ | |
1175 | ||
1176 | current->self_exec_id++; | |
1177 | ||
1178 | flush_signal_handlers(current, 0); | |
1179 | flush_old_files(current->files); | |
1da177e4 | 1180 | } |
221af7f8 | 1181 | EXPORT_SYMBOL(setup_new_exec); |
1da177e4 | 1182 | |
a2a8474c ON |
1183 | /* |
1184 | * Prepare credentials and lock ->cred_guard_mutex. | |
1185 | * install_exec_creds() commits the new creds and drops the lock. | |
1186 | * Or, if exec fails before, free_bprm() should release ->cred and | |
1187 | * and unlock. | |
1188 | */ | |
1189 | int prepare_bprm_creds(struct linux_binprm *bprm) | |
1190 | { | |
9b1bf12d | 1191 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
a2a8474c ON |
1192 | return -ERESTARTNOINTR; |
1193 | ||
1194 | bprm->cred = prepare_exec_creds(); | |
1195 | if (likely(bprm->cred)) | |
1196 | return 0; | |
1197 | ||
9b1bf12d | 1198 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1199 | return -ENOMEM; |
1200 | } | |
1201 | ||
1202 | void free_bprm(struct linux_binprm *bprm) | |
1203 | { | |
1204 | free_arg_pages(bprm); | |
1205 | if (bprm->cred) { | |
9b1bf12d | 1206 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1207 | abort_creds(bprm->cred); |
1208 | } | |
1209 | kfree(bprm); | |
1210 | } | |
1211 | ||
a6f76f23 DH |
1212 | /* |
1213 | * install the new credentials for this executable | |
1214 | */ | |
1215 | void install_exec_creds(struct linux_binprm *bprm) | |
1216 | { | |
1217 | security_bprm_committing_creds(bprm); | |
1218 | ||
1219 | commit_creds(bprm->cred); | |
1220 | bprm->cred = NULL; | |
a2a8474c ON |
1221 | /* |
1222 | * cred_guard_mutex must be held at least to this point to prevent | |
a6f76f23 | 1223 | * ptrace_attach() from altering our determination of the task's |
a2a8474c ON |
1224 | * credentials; any time after this it may be unlocked. |
1225 | */ | |
a6f76f23 | 1226 | security_bprm_committed_creds(bprm); |
9b1bf12d | 1227 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a6f76f23 DH |
1228 | } |
1229 | EXPORT_SYMBOL(install_exec_creds); | |
1230 | ||
1231 | /* | |
1232 | * determine how safe it is to execute the proposed program | |
9b1bf12d | 1233 | * - the caller must hold ->cred_guard_mutex to protect against |
a6f76f23 DH |
1234 | * PTRACE_ATTACH |
1235 | */ | |
f47ec3f2 | 1236 | static int check_unsafe_exec(struct linux_binprm *bprm) |
a6f76f23 | 1237 | { |
0bf2f3ae | 1238 | struct task_struct *p = current, *t; |
f1191b50 | 1239 | unsigned n_fs; |
498052bb | 1240 | int res = 0; |
a6f76f23 | 1241 | |
4b9d33e6 TH |
1242 | if (p->ptrace) { |
1243 | if (p->ptrace & PT_PTRACE_CAP) | |
1244 | bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP; | |
1245 | else | |
1246 | bprm->unsafe |= LSM_UNSAFE_PTRACE; | |
1247 | } | |
a6f76f23 | 1248 | |
0bf2f3ae | 1249 | n_fs = 1; |
2a4419b5 | 1250 | spin_lock(&p->fs->lock); |
437f7fdb | 1251 | rcu_read_lock(); |
0bf2f3ae DH |
1252 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
1253 | if (t->fs == p->fs) | |
1254 | n_fs++; | |
0bf2f3ae | 1255 | } |
437f7fdb | 1256 | rcu_read_unlock(); |
0bf2f3ae | 1257 | |
f1191b50 | 1258 | if (p->fs->users > n_fs) { |
a6f76f23 | 1259 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
498052bb | 1260 | } else { |
8c652f96 ON |
1261 | res = -EAGAIN; |
1262 | if (!p->fs->in_exec) { | |
1263 | p->fs->in_exec = 1; | |
1264 | res = 1; | |
1265 | } | |
498052bb | 1266 | } |
2a4419b5 | 1267 | spin_unlock(&p->fs->lock); |
498052bb AV |
1268 | |
1269 | return res; | |
a6f76f23 DH |
1270 | } |
1271 | ||
1da177e4 LT |
1272 | /* |
1273 | * Fill the binprm structure from the inode. | |
1274 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
a6f76f23 DH |
1275 | * |
1276 | * This may be called multiple times for binary chains (scripts for example). | |
1da177e4 LT |
1277 | */ |
1278 | int prepare_binprm(struct linux_binprm *bprm) | |
1279 | { | |
a6f76f23 | 1280 | umode_t mode; |
0f7fc9e4 | 1281 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
1282 | int retval; |
1283 | ||
1284 | mode = inode->i_mode; | |
1da177e4 LT |
1285 | if (bprm->file->f_op == NULL) |
1286 | return -EACCES; | |
1287 | ||
a6f76f23 DH |
1288 | /* clear any previous set[ug]id data from a previous binary */ |
1289 | bprm->cred->euid = current_euid(); | |
1290 | bprm->cred->egid = current_egid(); | |
1da177e4 | 1291 | |
a6f76f23 | 1292 | if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
1da177e4 LT |
1293 | /* Set-uid? */ |
1294 | if (mode & S_ISUID) { | |
a6f76f23 DH |
1295 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1296 | bprm->cred->euid = inode->i_uid; | |
1da177e4 LT |
1297 | } |
1298 | ||
1299 | /* Set-gid? */ | |
1300 | /* | |
1301 | * If setgid is set but no group execute bit then this | |
1302 | * is a candidate for mandatory locking, not a setgid | |
1303 | * executable. | |
1304 | */ | |
1305 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
a6f76f23 DH |
1306 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1307 | bprm->cred->egid = inode->i_gid; | |
1da177e4 LT |
1308 | } |
1309 | } | |
1310 | ||
1311 | /* fill in binprm security blob */ | |
a6f76f23 | 1312 | retval = security_bprm_set_creds(bprm); |
1da177e4 LT |
1313 | if (retval) |
1314 | return retval; | |
a6f76f23 | 1315 | bprm->cred_prepared = 1; |
1da177e4 | 1316 | |
a6f76f23 DH |
1317 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
1318 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); | |
1da177e4 LT |
1319 | } |
1320 | ||
1321 | EXPORT_SYMBOL(prepare_binprm); | |
1322 | ||
4fc75ff4 NP |
1323 | /* |
1324 | * Arguments are '\0' separated strings found at the location bprm->p | |
1325 | * points to; chop off the first by relocating brpm->p to right after | |
1326 | * the first '\0' encountered. | |
1327 | */ | |
b6a2fea3 | 1328 | int remove_arg_zero(struct linux_binprm *bprm) |
1da177e4 | 1329 | { |
b6a2fea3 OW |
1330 | int ret = 0; |
1331 | unsigned long offset; | |
1332 | char *kaddr; | |
1333 | struct page *page; | |
4fc75ff4 | 1334 | |
b6a2fea3 OW |
1335 | if (!bprm->argc) |
1336 | return 0; | |
1da177e4 | 1337 | |
b6a2fea3 OW |
1338 | do { |
1339 | offset = bprm->p & ~PAGE_MASK; | |
1340 | page = get_arg_page(bprm, bprm->p, 0); | |
1341 | if (!page) { | |
1342 | ret = -EFAULT; | |
1343 | goto out; | |
1344 | } | |
e8e3c3d6 | 1345 | kaddr = kmap_atomic(page); |
4fc75ff4 | 1346 | |
b6a2fea3 OW |
1347 | for (; offset < PAGE_SIZE && kaddr[offset]; |
1348 | offset++, bprm->p++) | |
1349 | ; | |
4fc75ff4 | 1350 | |
e8e3c3d6 | 1351 | kunmap_atomic(kaddr); |
b6a2fea3 | 1352 | put_arg_page(page); |
4fc75ff4 | 1353 | |
b6a2fea3 OW |
1354 | if (offset == PAGE_SIZE) |
1355 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); | |
1356 | } while (offset == PAGE_SIZE); | |
4fc75ff4 | 1357 | |
b6a2fea3 OW |
1358 | bprm->p++; |
1359 | bprm->argc--; | |
1360 | ret = 0; | |
4fc75ff4 | 1361 | |
b6a2fea3 OW |
1362 | out: |
1363 | return ret; | |
1da177e4 | 1364 | } |
1da177e4 LT |
1365 | EXPORT_SYMBOL(remove_arg_zero); |
1366 | ||
1367 | /* | |
1368 | * cycle the list of binary formats handler, until one recognizes the image | |
1369 | */ | |
1370 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1371 | { | |
85f33466 | 1372 | unsigned int depth = bprm->recursion_depth; |
1da177e4 LT |
1373 | int try,retval; |
1374 | struct linux_binfmt *fmt; | |
bb188d7e | 1375 | pid_t old_pid; |
1da177e4 | 1376 | |
1da177e4 LT |
1377 | retval = security_bprm_check(bprm); |
1378 | if (retval) | |
1379 | return retval; | |
1380 | ||
473ae30b AV |
1381 | retval = audit_bprm(bprm); |
1382 | if (retval) | |
1383 | return retval; | |
1384 | ||
bb188d7e DV |
1385 | /* Need to fetch pid before load_binary changes it */ |
1386 | rcu_read_lock(); | |
1387 | old_pid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); | |
1388 | rcu_read_unlock(); | |
1389 | ||
1da177e4 LT |
1390 | retval = -ENOENT; |
1391 | for (try=0; try<2; try++) { | |
1392 | read_lock(&binfmt_lock); | |
e4dc1b14 | 1393 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
1394 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
1395 | if (!fn) | |
1396 | continue; | |
1397 | if (!try_module_get(fmt->module)) | |
1398 | continue; | |
1399 | read_unlock(&binfmt_lock); | |
1400 | retval = fn(bprm, regs); | |
85f33466 RM |
1401 | /* |
1402 | * Restore the depth counter to its starting value | |
1403 | * in this call, so we don't have to rely on every | |
1404 | * load_binary function to restore it on return. | |
1405 | */ | |
1406 | bprm->recursion_depth = depth; | |
1da177e4 | 1407 | if (retval >= 0) { |
4ff16c25 DS |
1408 | if (depth == 0) { |
1409 | trace_sched_process_exec(current, old_pid, bprm); | |
1410 | ptrace_event(PTRACE_EVENT_EXEC, old_pid); | |
1411 | } | |
1da177e4 LT |
1412 | put_binfmt(fmt); |
1413 | allow_write_access(bprm->file); | |
1414 | if (bprm->file) | |
1415 | fput(bprm->file); | |
1416 | bprm->file = NULL; | |
1417 | current->did_exec = 1; | |
9f46080c | 1418 | proc_exec_connector(current); |
1da177e4 LT |
1419 | return retval; |
1420 | } | |
1421 | read_lock(&binfmt_lock); | |
1422 | put_binfmt(fmt); | |
1423 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1424 | break; | |
1425 | if (!bprm->file) { | |
1426 | read_unlock(&binfmt_lock); | |
1427 | return retval; | |
1428 | } | |
1429 | } | |
1430 | read_unlock(&binfmt_lock); | |
b4edf8bd | 1431 | #ifdef CONFIG_MODULES |
1da177e4 LT |
1432 | if (retval != -ENOEXEC || bprm->mm == NULL) { |
1433 | break; | |
5f4123be | 1434 | } else { |
1da177e4 LT |
1435 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
1436 | if (printable(bprm->buf[0]) && | |
1437 | printable(bprm->buf[1]) && | |
1438 | printable(bprm->buf[2]) && | |
1439 | printable(bprm->buf[3])) | |
1440 | break; /* -ENOEXEC */ | |
91219352 TH |
1441 | if (try) |
1442 | break; /* -ENOEXEC */ | |
1da177e4 | 1443 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); |
1da177e4 | 1444 | } |
b4edf8bd TH |
1445 | #else |
1446 | break; | |
1447 | #endif | |
1da177e4 LT |
1448 | } |
1449 | return retval; | |
1450 | } | |
1451 | ||
1452 | EXPORT_SYMBOL(search_binary_handler); | |
1453 | ||
1454 | /* | |
1455 | * sys_execve() executes a new program. | |
1456 | */ | |
ba2d0162 ON |
1457 | static int do_execve_common(const char *filename, |
1458 | struct user_arg_ptr argv, | |
1459 | struct user_arg_ptr envp, | |
1460 | struct pt_regs *regs) | |
1da177e4 LT |
1461 | { |
1462 | struct linux_binprm *bprm; | |
1463 | struct file *file; | |
3b125388 | 1464 | struct files_struct *displaced; |
8c652f96 | 1465 | bool clear_in_exec; |
1da177e4 | 1466 | int retval; |
72fa5997 VK |
1467 | const struct cred *cred = current_cred(); |
1468 | ||
1469 | /* | |
1470 | * We move the actual failure in case of RLIMIT_NPROC excess from | |
1471 | * set*uid() to execve() because too many poorly written programs | |
1472 | * don't check setuid() return code. Here we additionally recheck | |
1473 | * whether NPROC limit is still exceeded. | |
1474 | */ | |
1475 | if ((current->flags & PF_NPROC_EXCEEDED) && | |
1476 | atomic_read(&cred->user->processes) > rlimit(RLIMIT_NPROC)) { | |
1477 | retval = -EAGAIN; | |
1478 | goto out_ret; | |
1479 | } | |
1480 | ||
1481 | /* We're below the limit (still or again), so we don't want to make | |
1482 | * further execve() calls fail. */ | |
1483 | current->flags &= ~PF_NPROC_EXCEEDED; | |
1da177e4 | 1484 | |
3b125388 | 1485 | retval = unshare_files(&displaced); |
fd8328be AV |
1486 | if (retval) |
1487 | goto out_ret; | |
1488 | ||
1da177e4 | 1489 | retval = -ENOMEM; |
11b0b5ab | 1490 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1da177e4 | 1491 | if (!bprm) |
fd8328be | 1492 | goto out_files; |
1da177e4 | 1493 | |
a2a8474c ON |
1494 | retval = prepare_bprm_creds(bprm); |
1495 | if (retval) | |
a6f76f23 | 1496 | goto out_free; |
498052bb AV |
1497 | |
1498 | retval = check_unsafe_exec(bprm); | |
8c652f96 | 1499 | if (retval < 0) |
a2a8474c | 1500 | goto out_free; |
8c652f96 | 1501 | clear_in_exec = retval; |
a2a8474c | 1502 | current->in_execve = 1; |
a6f76f23 | 1503 | |
1da177e4 LT |
1504 | file = open_exec(filename); |
1505 | retval = PTR_ERR(file); | |
1506 | if (IS_ERR(file)) | |
498052bb | 1507 | goto out_unmark; |
1da177e4 LT |
1508 | |
1509 | sched_exec(); | |
1510 | ||
1da177e4 LT |
1511 | bprm->file = file; |
1512 | bprm->filename = filename; | |
1513 | bprm->interp = filename; | |
1da177e4 | 1514 | |
b6a2fea3 OW |
1515 | retval = bprm_mm_init(bprm); |
1516 | if (retval) | |
1517 | goto out_file; | |
1da177e4 | 1518 | |
b6a2fea3 | 1519 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
1da177e4 | 1520 | if ((retval = bprm->argc) < 0) |
a6f76f23 | 1521 | goto out; |
1da177e4 | 1522 | |
b6a2fea3 | 1523 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
1da177e4 | 1524 | if ((retval = bprm->envc) < 0) |
1da177e4 LT |
1525 | goto out; |
1526 | ||
1527 | retval = prepare_binprm(bprm); | |
1528 | if (retval < 0) | |
1529 | goto out; | |
1530 | ||
1531 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1532 | if (retval < 0) | |
1533 | goto out; | |
1534 | ||
1535 | bprm->exec = bprm->p; | |
1536 | retval = copy_strings(bprm->envc, envp, bprm); | |
1537 | if (retval < 0) | |
1538 | goto out; | |
1539 | ||
1540 | retval = copy_strings(bprm->argc, argv, bprm); | |
1541 | if (retval < 0) | |
1542 | goto out; | |
1543 | ||
1544 | retval = search_binary_handler(bprm,regs); | |
a6f76f23 DH |
1545 | if (retval < 0) |
1546 | goto out; | |
1da177e4 | 1547 | |
a6f76f23 | 1548 | /* execve succeeded */ |
498052bb | 1549 | current->fs->in_exec = 0; |
f9ce1f1c | 1550 | current->in_execve = 0; |
a6f76f23 DH |
1551 | acct_update_integrals(current); |
1552 | free_bprm(bprm); | |
1553 | if (displaced) | |
1554 | put_files_struct(displaced); | |
1555 | return retval; | |
1da177e4 | 1556 | |
a6f76f23 | 1557 | out: |
3c77f845 ON |
1558 | if (bprm->mm) { |
1559 | acct_arg_size(bprm, 0); | |
1560 | mmput(bprm->mm); | |
1561 | } | |
1da177e4 LT |
1562 | |
1563 | out_file: | |
1564 | if (bprm->file) { | |
1565 | allow_write_access(bprm->file); | |
1566 | fput(bprm->file); | |
1567 | } | |
a6f76f23 | 1568 | |
498052bb | 1569 | out_unmark: |
8c652f96 ON |
1570 | if (clear_in_exec) |
1571 | current->fs->in_exec = 0; | |
f9ce1f1c | 1572 | current->in_execve = 0; |
a6f76f23 DH |
1573 | |
1574 | out_free: | |
08a6fac1 | 1575 | free_bprm(bprm); |
1da177e4 | 1576 | |
fd8328be | 1577 | out_files: |
3b125388 AV |
1578 | if (displaced) |
1579 | reset_files_struct(displaced); | |
1da177e4 LT |
1580 | out_ret: |
1581 | return retval; | |
1582 | } | |
1583 | ||
ba2d0162 ON |
1584 | int do_execve(const char *filename, |
1585 | const char __user *const __user *__argv, | |
1586 | const char __user *const __user *__envp, | |
1587 | struct pt_regs *regs) | |
1588 | { | |
0e028465 ON |
1589 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
1590 | struct user_arg_ptr envp = { .ptr.native = __envp }; | |
1591 | return do_execve_common(filename, argv, envp, regs); | |
1592 | } | |
1593 | ||
1594 | #ifdef CONFIG_COMPAT | |
1595 | int compat_do_execve(char *filename, | |
1596 | compat_uptr_t __user *__argv, | |
1597 | compat_uptr_t __user *__envp, | |
1598 | struct pt_regs *regs) | |
1599 | { | |
1600 | struct user_arg_ptr argv = { | |
1601 | .is_compat = true, | |
1602 | .ptr.compat = __argv, | |
1603 | }; | |
1604 | struct user_arg_ptr envp = { | |
1605 | .is_compat = true, | |
1606 | .ptr.compat = __envp, | |
1607 | }; | |
ba2d0162 ON |
1608 | return do_execve_common(filename, argv, envp, regs); |
1609 | } | |
0e028465 | 1610 | #endif |
ba2d0162 | 1611 | |
964ee7df | 1612 | void set_binfmt(struct linux_binfmt *new) |
1da177e4 | 1613 | { |
801460d0 HS |
1614 | struct mm_struct *mm = current->mm; |
1615 | ||
1616 | if (mm->binfmt) | |
1617 | module_put(mm->binfmt->module); | |
1da177e4 | 1618 | |
801460d0 | 1619 | mm->binfmt = new; |
964ee7df ON |
1620 | if (new) |
1621 | __module_get(new->module); | |
1da177e4 LT |
1622 | } |
1623 | ||
1624 | EXPORT_SYMBOL(set_binfmt); | |
1625 | ||
1b0d300b XF |
1626 | static int expand_corename(struct core_name *cn) |
1627 | { | |
1628 | char *old_corename = cn->corename; | |
1629 | ||
1630 | cn->size = CORENAME_MAX_SIZE * atomic_inc_return(&call_count); | |
1631 | cn->corename = krealloc(old_corename, cn->size, GFP_KERNEL); | |
1632 | ||
1633 | if (!cn->corename) { | |
1634 | kfree(old_corename); | |
1635 | return -ENOMEM; | |
1636 | } | |
1637 | ||
1638 | return 0; | |
1639 | } | |
1640 | ||
1641 | static int cn_printf(struct core_name *cn, const char *fmt, ...) | |
1642 | { | |
1643 | char *cur; | |
1644 | int need; | |
1645 | int ret; | |
1646 | va_list arg; | |
1647 | ||
1648 | va_start(arg, fmt); | |
1649 | need = vsnprintf(NULL, 0, fmt, arg); | |
1650 | va_end(arg); | |
1651 | ||
1652 | if (likely(need < cn->size - cn->used - 1)) | |
1653 | goto out_printf; | |
1654 | ||
1655 | ret = expand_corename(cn); | |
1656 | if (ret) | |
1657 | goto expand_fail; | |
1658 | ||
1659 | out_printf: | |
1660 | cur = cn->corename + cn->used; | |
1661 | va_start(arg, fmt); | |
1662 | vsnprintf(cur, need + 1, fmt, arg); | |
1663 | va_end(arg); | |
1664 | cn->used += need; | |
1665 | return 0; | |
1666 | ||
1667 | expand_fail: | |
1668 | return ret; | |
1669 | } | |
1670 | ||
2c563731 JS |
1671 | static void cn_escape(char *str) |
1672 | { | |
1673 | for (; *str; str++) | |
1674 | if (*str == '/') | |
1675 | *str = '!'; | |
1676 | } | |
1677 | ||
57cc083a JS |
1678 | static int cn_print_exe_file(struct core_name *cn) |
1679 | { | |
1680 | struct file *exe_file; | |
2c563731 | 1681 | char *pathbuf, *path; |
57cc083a JS |
1682 | int ret; |
1683 | ||
1684 | exe_file = get_mm_exe_file(current->mm); | |
2c563731 JS |
1685 | if (!exe_file) { |
1686 | char *commstart = cn->corename + cn->used; | |
1687 | ret = cn_printf(cn, "%s (path unknown)", current->comm); | |
1688 | cn_escape(commstart); | |
1689 | return ret; | |
1690 | } | |
57cc083a JS |
1691 | |
1692 | pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY); | |
1693 | if (!pathbuf) { | |
1694 | ret = -ENOMEM; | |
1695 | goto put_exe_file; | |
1696 | } | |
1697 | ||
1698 | path = d_path(&exe_file->f_path, pathbuf, PATH_MAX); | |
1699 | if (IS_ERR(path)) { | |
1700 | ret = PTR_ERR(path); | |
1701 | goto free_buf; | |
1702 | } | |
1703 | ||
2c563731 | 1704 | cn_escape(path); |
57cc083a JS |
1705 | |
1706 | ret = cn_printf(cn, "%s", path); | |
1707 | ||
1708 | free_buf: | |
1709 | kfree(pathbuf); | |
1710 | put_exe_file: | |
1711 | fput(exe_file); | |
1712 | return ret; | |
1713 | } | |
1714 | ||
1da177e4 LT |
1715 | /* format_corename will inspect the pattern parameter, and output a |
1716 | * name into corename, which must have space for at least | |
1717 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
1718 | */ | |
1b0d300b | 1719 | static int format_corename(struct core_name *cn, long signr) |
1da177e4 | 1720 | { |
86a264ab | 1721 | const struct cred *cred = current_cred(); |
565b9b14 ON |
1722 | const char *pat_ptr = core_pattern; |
1723 | int ispipe = (*pat_ptr == '|'); | |
1da177e4 | 1724 | int pid_in_pattern = 0; |
1b0d300b XF |
1725 | int err = 0; |
1726 | ||
1727 | cn->size = CORENAME_MAX_SIZE * atomic_read(&call_count); | |
1728 | cn->corename = kmalloc(cn->size, GFP_KERNEL); | |
1729 | cn->used = 0; | |
1730 | ||
1731 | if (!cn->corename) | |
1732 | return -ENOMEM; | |
1da177e4 LT |
1733 | |
1734 | /* Repeat as long as we have more pattern to process and more output | |
1735 | space */ | |
1736 | while (*pat_ptr) { | |
1737 | if (*pat_ptr != '%') { | |
1b0d300b | 1738 | if (*pat_ptr == 0) |
1da177e4 | 1739 | goto out; |
1b0d300b | 1740 | err = cn_printf(cn, "%c", *pat_ptr++); |
1da177e4 LT |
1741 | } else { |
1742 | switch (*++pat_ptr) { | |
1b0d300b | 1743 | /* single % at the end, drop that */ |
1da177e4 LT |
1744 | case 0: |
1745 | goto out; | |
1746 | /* Double percent, output one percent */ | |
1747 | case '%': | |
1b0d300b | 1748 | err = cn_printf(cn, "%c", '%'); |
1da177e4 LT |
1749 | break; |
1750 | /* pid */ | |
1751 | case 'p': | |
1752 | pid_in_pattern = 1; | |
1b0d300b XF |
1753 | err = cn_printf(cn, "%d", |
1754 | task_tgid_vnr(current)); | |
1da177e4 LT |
1755 | break; |
1756 | /* uid */ | |
1757 | case 'u': | |
1b0d300b | 1758 | err = cn_printf(cn, "%d", cred->uid); |
1da177e4 LT |
1759 | break; |
1760 | /* gid */ | |
1761 | case 'g': | |
1b0d300b | 1762 | err = cn_printf(cn, "%d", cred->gid); |
1da177e4 LT |
1763 | break; |
1764 | /* signal that caused the coredump */ | |
1765 | case 's': | |
1b0d300b | 1766 | err = cn_printf(cn, "%ld", signr); |
1da177e4 LT |
1767 | break; |
1768 | /* UNIX time of coredump */ | |
1769 | case 't': { | |
1770 | struct timeval tv; | |
1771 | do_gettimeofday(&tv); | |
1b0d300b | 1772 | err = cn_printf(cn, "%lu", tv.tv_sec); |
1da177e4 LT |
1773 | break; |
1774 | } | |
1775 | /* hostname */ | |
2c563731 JS |
1776 | case 'h': { |
1777 | char *namestart = cn->corename + cn->used; | |
1da177e4 | 1778 | down_read(&uts_sem); |
1b0d300b XF |
1779 | err = cn_printf(cn, "%s", |
1780 | utsname()->nodename); | |
1da177e4 | 1781 | up_read(&uts_sem); |
2c563731 | 1782 | cn_escape(namestart); |
1da177e4 | 1783 | break; |
2c563731 | 1784 | } |
1da177e4 | 1785 | /* executable */ |
2c563731 JS |
1786 | case 'e': { |
1787 | char *commstart = cn->corename + cn->used; | |
1b0d300b | 1788 | err = cn_printf(cn, "%s", current->comm); |
2c563731 | 1789 | cn_escape(commstart); |
1da177e4 | 1790 | break; |
2c563731 | 1791 | } |
57cc083a JS |
1792 | case 'E': |
1793 | err = cn_print_exe_file(cn); | |
1794 | break; | |
74aadce9 NH |
1795 | /* core limit size */ |
1796 | case 'c': | |
1b0d300b XF |
1797 | err = cn_printf(cn, "%lu", |
1798 | rlimit(RLIMIT_CORE)); | |
74aadce9 | 1799 | break; |
1da177e4 LT |
1800 | default: |
1801 | break; | |
1802 | } | |
1803 | ++pat_ptr; | |
1804 | } | |
1b0d300b XF |
1805 | |
1806 | if (err) | |
1807 | return err; | |
1da177e4 | 1808 | } |
1b0d300b | 1809 | |
1da177e4 LT |
1810 | /* Backward compatibility with core_uses_pid: |
1811 | * | |
1812 | * If core_pattern does not include a %p (as is the default) | |
1813 | * and core_uses_pid is set, then .%pid will be appended to | |
c4bbafda | 1814 | * the filename. Do not do this for piped commands. */ |
6409324b | 1815 | if (!ispipe && !pid_in_pattern && core_uses_pid) { |
1b0d300b XF |
1816 | err = cn_printf(cn, ".%d", task_tgid_vnr(current)); |
1817 | if (err) | |
1818 | return err; | |
1da177e4 | 1819 | } |
c4bbafda | 1820 | out: |
c4bbafda | 1821 | return ispipe; |
1da177e4 LT |
1822 | } |
1823 | ||
5c99cbf4 | 1824 | static int zap_process(struct task_struct *start, int exit_code) |
aceecc04 ON |
1825 | { |
1826 | struct task_struct *t; | |
8cd9c249 | 1827 | int nr = 0; |
281de339 | 1828 | |
d5f70c00 | 1829 | start->signal->flags = SIGNAL_GROUP_EXIT; |
5c99cbf4 | 1830 | start->signal->group_exit_code = exit_code; |
d5f70c00 | 1831 | start->signal->group_stop_count = 0; |
aceecc04 ON |
1832 | |
1833 | t = start; | |
1834 | do { | |
6dfca329 | 1835 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); |
aceecc04 | 1836 | if (t != current && t->mm) { |
281de339 ON |
1837 | sigaddset(&t->pending.signal, SIGKILL); |
1838 | signal_wake_up(t, 1); | |
8cd9c249 | 1839 | nr++; |
aceecc04 | 1840 | } |
e4901f92 | 1841 | } while_each_thread(start, t); |
8cd9c249 ON |
1842 | |
1843 | return nr; | |
aceecc04 ON |
1844 | } |
1845 | ||
dcf560c5 | 1846 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
8cd9c249 | 1847 | struct core_state *core_state, int exit_code) |
1da177e4 LT |
1848 | { |
1849 | struct task_struct *g, *p; | |
5debfa6d | 1850 | unsigned long flags; |
8cd9c249 | 1851 | int nr = -EAGAIN; |
dcf560c5 ON |
1852 | |
1853 | spin_lock_irq(&tsk->sighand->siglock); | |
ed5d2cac | 1854 | if (!signal_group_exit(tsk->signal)) { |
8cd9c249 | 1855 | mm->core_state = core_state; |
5c99cbf4 | 1856 | nr = zap_process(tsk, exit_code); |
1da177e4 | 1857 | } |
dcf560c5 | 1858 | spin_unlock_irq(&tsk->sighand->siglock); |
8cd9c249 ON |
1859 | if (unlikely(nr < 0)) |
1860 | return nr; | |
1da177e4 | 1861 | |
8cd9c249 | 1862 | if (atomic_read(&mm->mm_users) == nr + 1) |
5debfa6d | 1863 | goto done; |
e4901f92 ON |
1864 | /* |
1865 | * We should find and kill all tasks which use this mm, and we should | |
999d9fc1 | 1866 | * count them correctly into ->nr_threads. We don't take tasklist |
e4901f92 ON |
1867 | * lock, but this is safe wrt: |
1868 | * | |
1869 | * fork: | |
1870 | * None of sub-threads can fork after zap_process(leader). All | |
1871 | * processes which were created before this point should be | |
1872 | * visible to zap_threads() because copy_process() adds the new | |
1873 | * process to the tail of init_task.tasks list, and lock/unlock | |
1874 | * of ->siglock provides a memory barrier. | |
1875 | * | |
1876 | * do_exit: | |
1877 | * The caller holds mm->mmap_sem. This means that the task which | |
1878 | * uses this mm can't pass exit_mm(), so it can't exit or clear | |
1879 | * its ->mm. | |
1880 | * | |
1881 | * de_thread: | |
1882 | * It does list_replace_rcu(&leader->tasks, ¤t->tasks), | |
1883 | * we must see either old or new leader, this does not matter. | |
1884 | * However, it can change p->sighand, so lock_task_sighand(p) | |
1885 | * must be used. Since p->mm != NULL and we hold ->mmap_sem | |
1886 | * it can't fail. | |
1887 | * | |
1888 | * Note also that "g" can be the old leader with ->mm == NULL | |
1889 | * and already unhashed and thus removed from ->thread_group. | |
1890 | * This is OK, __unhash_process()->list_del_rcu() does not | |
1891 | * clear the ->next pointer, we will find the new leader via | |
1892 | * next_thread(). | |
1893 | */ | |
7b1c6154 | 1894 | rcu_read_lock(); |
aceecc04 | 1895 | for_each_process(g) { |
5debfa6d ON |
1896 | if (g == tsk->group_leader) |
1897 | continue; | |
15b9f360 ON |
1898 | if (g->flags & PF_KTHREAD) |
1899 | continue; | |
aceecc04 ON |
1900 | p = g; |
1901 | do { | |
1902 | if (p->mm) { | |
15b9f360 | 1903 | if (unlikely(p->mm == mm)) { |
5debfa6d | 1904 | lock_task_sighand(p, &flags); |
5c99cbf4 | 1905 | nr += zap_process(p, exit_code); |
5debfa6d ON |
1906 | unlock_task_sighand(p, &flags); |
1907 | } | |
aceecc04 ON |
1908 | break; |
1909 | } | |
e4901f92 | 1910 | } while_each_thread(g, p); |
aceecc04 | 1911 | } |
7b1c6154 | 1912 | rcu_read_unlock(); |
5debfa6d | 1913 | done: |
c5f1cc8c | 1914 | atomic_set(&core_state->nr_threads, nr); |
8cd9c249 | 1915 | return nr; |
1da177e4 LT |
1916 | } |
1917 | ||
9d5b327b | 1918 | static int coredump_wait(int exit_code, struct core_state *core_state) |
1da177e4 | 1919 | { |
dcf560c5 ON |
1920 | struct task_struct *tsk = current; |
1921 | struct mm_struct *mm = tsk->mm; | |
269b005a | 1922 | int core_waiters = -EBUSY; |
1da177e4 | 1923 | |
9d5b327b | 1924 | init_completion(&core_state->startup); |
b564daf8 ON |
1925 | core_state->dumper.task = tsk; |
1926 | core_state->dumper.next = NULL; | |
269b005a ON |
1927 | |
1928 | down_write(&mm->mmap_sem); | |
1929 | if (!mm->core_state) | |
1930 | core_waiters = zap_threads(tsk, mm, core_state, exit_code); | |
2384f55f ON |
1931 | up_write(&mm->mmap_sem); |
1932 | ||
57b59c4a | 1933 | if (core_waiters > 0) |
9d5b327b | 1934 | wait_for_completion(&core_state->startup); |
57b59c4a | 1935 | |
dcf560c5 | 1936 | return core_waiters; |
1da177e4 LT |
1937 | } |
1938 | ||
a94e2d40 ON |
1939 | static void coredump_finish(struct mm_struct *mm) |
1940 | { | |
1941 | struct core_thread *curr, *next; | |
1942 | struct task_struct *task; | |
1943 | ||
1944 | next = mm->core_state->dumper.next; | |
1945 | while ((curr = next) != NULL) { | |
1946 | next = curr->next; | |
1947 | task = curr->task; | |
1948 | /* | |
1949 | * see exit_mm(), curr->task must not see | |
1950 | * ->task == NULL before we read ->next. | |
1951 | */ | |
1952 | smp_mb(); | |
1953 | curr->task = NULL; | |
1954 | wake_up_process(task); | |
1955 | } | |
1956 | ||
1957 | mm->core_state = NULL; | |
1958 | } | |
1959 | ||
6c5d5238 KH |
1960 | /* |
1961 | * set_dumpable converts traditional three-value dumpable to two flags and | |
1962 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but | |
1963 | * these bits are not changed atomically. So get_dumpable can observe the | |
1964 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable | |
1965 | * return either old dumpable or new one by paying attention to the order of | |
1966 | * modifying the bits. | |
1967 | * | |
1968 | * dumpable | mm->flags (binary) | |
1969 | * old new | initial interim final | |
1970 | * ---------+----------------------- | |
1971 | * 0 1 | 00 01 01 | |
1972 | * 0 2 | 00 10(*) 11 | |
1973 | * 1 0 | 01 00 00 | |
1974 | * 1 2 | 01 11 11 | |
1975 | * 2 0 | 11 10(*) 00 | |
1976 | * 2 1 | 11 11 01 | |
1977 | * | |
1978 | * (*) get_dumpable regards interim value of 10 as 11. | |
1979 | */ | |
1980 | void set_dumpable(struct mm_struct *mm, int value) | |
1981 | { | |
1982 | switch (value) { | |
1983 | case 0: | |
1984 | clear_bit(MMF_DUMPABLE, &mm->flags); | |
1985 | smp_wmb(); | |
1986 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1987 | break; | |
1988 | case 1: | |
1989 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1990 | smp_wmb(); | |
1991 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1992 | break; | |
1993 | case 2: | |
1994 | set_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1995 | smp_wmb(); | |
1996 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1997 | break; | |
1998 | } | |
1999 | } | |
6c5d5238 | 2000 | |
30736a4d | 2001 | static int __get_dumpable(unsigned long mm_flags) |
6c5d5238 KH |
2002 | { |
2003 | int ret; | |
2004 | ||
30736a4d | 2005 | ret = mm_flags & MMF_DUMPABLE_MASK; |
6c5d5238 KH |
2006 | return (ret >= 2) ? 2 : ret; |
2007 | } | |
2008 | ||
30736a4d MH |
2009 | int get_dumpable(struct mm_struct *mm) |
2010 | { | |
2011 | return __get_dumpable(mm->flags); | |
2012 | } | |
2013 | ||
61be228a NH |
2014 | static void wait_for_dump_helpers(struct file *file) |
2015 | { | |
2016 | struct pipe_inode_info *pipe; | |
2017 | ||
2018 | pipe = file->f_path.dentry->d_inode->i_pipe; | |
2019 | ||
2020 | pipe_lock(pipe); | |
2021 | pipe->readers++; | |
2022 | pipe->writers--; | |
2023 | ||
2024 | while ((pipe->readers > 1) && (!signal_pending(current))) { | |
2025 | wake_up_interruptible_sync(&pipe->wait); | |
2026 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); | |
2027 | pipe_wait(pipe); | |
2028 | } | |
2029 | ||
2030 | pipe->readers--; | |
2031 | pipe->writers++; | |
2032 | pipe_unlock(pipe); | |
2033 | ||
2034 | } | |
2035 | ||
2036 | ||
898b374a | 2037 | /* |
1bef8291 | 2038 | * umh_pipe_setup |
898b374a NH |
2039 | * helper function to customize the process used |
2040 | * to collect the core in userspace. Specifically | |
2041 | * it sets up a pipe and installs it as fd 0 (stdin) | |
2042 | * for the process. Returns 0 on success, or | |
2043 | * PTR_ERR on failure. | |
2044 | * Note that it also sets the core limit to 1. This | |
2045 | * is a special value that we use to trap recursive | |
2046 | * core dumps | |
2047 | */ | |
87966996 | 2048 | static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) |
898b374a NH |
2049 | { |
2050 | struct file *rp, *wp; | |
2051 | struct fdtable *fdt; | |
2052 | struct coredump_params *cp = (struct coredump_params *)info->data; | |
2053 | struct files_struct *cf = current->files; | |
2054 | ||
2055 | wp = create_write_pipe(0); | |
2056 | if (IS_ERR(wp)) | |
2057 | return PTR_ERR(wp); | |
2058 | ||
2059 | rp = create_read_pipe(wp, 0); | |
2060 | if (IS_ERR(rp)) { | |
2061 | free_write_pipe(wp); | |
2062 | return PTR_ERR(rp); | |
2063 | } | |
2064 | ||
2065 | cp->file = wp; | |
2066 | ||
2067 | sys_close(0); | |
2068 | fd_install(0, rp); | |
2069 | spin_lock(&cf->file_lock); | |
2070 | fdt = files_fdtable(cf); | |
2071 | FD_SET(0, fdt->open_fds); | |
2072 | FD_CLR(0, fdt->close_on_exec); | |
2073 | spin_unlock(&cf->file_lock); | |
2074 | ||
2075 | /* and disallow core files too */ | |
2076 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; | |
2077 | ||
2078 | return 0; | |
2079 | } | |
2080 | ||
8cd3ac3a | 2081 | void do_coredump(long signr, int exit_code, struct pt_regs *regs) |
1da177e4 | 2082 | { |
9d5b327b | 2083 | struct core_state core_state; |
1b0d300b | 2084 | struct core_name cn; |
1da177e4 LT |
2085 | struct mm_struct *mm = current->mm; |
2086 | struct linux_binfmt * binfmt; | |
d84f4f99 DH |
2087 | const struct cred *old_cred; |
2088 | struct cred *cred; | |
1da177e4 | 2089 | int retval = 0; |
d6e71144 | 2090 | int flag = 0; |
d5bf4c4f | 2091 | int ispipe; |
a293980c | 2092 | static atomic_t core_dump_count = ATOMIC_INIT(0); |
f6151dfe MH |
2093 | struct coredump_params cprm = { |
2094 | .signr = signr, | |
2095 | .regs = regs, | |
d554ed89 | 2096 | .limit = rlimit(RLIMIT_CORE), |
30736a4d MH |
2097 | /* |
2098 | * We must use the same mm->flags while dumping core to avoid | |
2099 | * inconsistency of bit flags, since this flag is not protected | |
2100 | * by any locks. | |
2101 | */ | |
2102 | .mm_flags = mm->flags, | |
f6151dfe | 2103 | }; |
1da177e4 | 2104 | |
0a4ff8c2 SG |
2105 | audit_core_dumps(signr); |
2106 | ||
801460d0 | 2107 | binfmt = mm->binfmt; |
1da177e4 LT |
2108 | if (!binfmt || !binfmt->core_dump) |
2109 | goto fail; | |
269b005a ON |
2110 | if (!__get_dumpable(cprm.mm_flags)) |
2111 | goto fail; | |
d84f4f99 DH |
2112 | |
2113 | cred = prepare_creds(); | |
5e43aef5 | 2114 | if (!cred) |
d84f4f99 | 2115 | goto fail; |
d6e71144 AC |
2116 | /* |
2117 | * We cannot trust fsuid as being the "true" uid of the | |
2118 | * process nor do we know its entire history. We only know it | |
2119 | * was tainted so we dump it as root in mode 2. | |
2120 | */ | |
30736a4d MH |
2121 | if (__get_dumpable(cprm.mm_flags) == 2) { |
2122 | /* Setuid core dump mode */ | |
d6e71144 | 2123 | flag = O_EXCL; /* Stop rewrite attacks */ |
d84f4f99 | 2124 | cred->fsuid = 0; /* Dump root private */ |
d6e71144 | 2125 | } |
1291cf41 | 2126 | |
9d5b327b | 2127 | retval = coredump_wait(exit_code, &core_state); |
5e43aef5 ON |
2128 | if (retval < 0) |
2129 | goto fail_creds; | |
d84f4f99 DH |
2130 | |
2131 | old_cred = override_creds(cred); | |
1da177e4 LT |
2132 | |
2133 | /* | |
2134 | * Clear any false indication of pending signals that might | |
2135 | * be seen by the filesystem code called to write the core file. | |
2136 | */ | |
1da177e4 LT |
2137 | clear_thread_flag(TIF_SIGPENDING); |
2138 | ||
1b0d300b XF |
2139 | ispipe = format_corename(&cn, signr); |
2140 | ||
c4bbafda | 2141 | if (ispipe) { |
d5bf4c4f ON |
2142 | int dump_count; |
2143 | char **helper_argv; | |
2144 | ||
99b64567 ON |
2145 | if (ispipe < 0) { |
2146 | printk(KERN_WARNING "format_corename failed\n"); | |
2147 | printk(KERN_WARNING "Aborting core\n"); | |
2148 | goto fail_corename; | |
2149 | } | |
2150 | ||
898b374a | 2151 | if (cprm.limit == 1) { |
725eae32 NH |
2152 | /* |
2153 | * Normally core limits are irrelevant to pipes, since | |
2154 | * we're not writing to the file system, but we use | |
898b374a NH |
2155 | * cprm.limit of 1 here as a speacial value. Any |
2156 | * non-1 limit gets set to RLIM_INFINITY below, but | |
725eae32 NH |
2157 | * a limit of 0 skips the dump. This is a consistent |
2158 | * way to catch recursive crashes. We can still crash | |
898b374a | 2159 | * if the core_pattern binary sets RLIM_CORE = !1 |
725eae32 NH |
2160 | * but it runs as root, and can do lots of stupid things |
2161 | * Note that we use task_tgid_vnr here to grab the pid | |
2162 | * of the process group leader. That way we get the | |
2163 | * right pid if a thread in a multi-threaded | |
2164 | * core_pattern process dies. | |
2165 | */ | |
2166 | printk(KERN_WARNING | |
898b374a | 2167 | "Process %d(%s) has RLIMIT_CORE set to 1\n", |
725eae32 NH |
2168 | task_tgid_vnr(current), current->comm); |
2169 | printk(KERN_WARNING "Aborting core\n"); | |
2170 | goto fail_unlock; | |
2171 | } | |
d5bf4c4f | 2172 | cprm.limit = RLIM_INFINITY; |
725eae32 | 2173 | |
a293980c NH |
2174 | dump_count = atomic_inc_return(&core_dump_count); |
2175 | if (core_pipe_limit && (core_pipe_limit < dump_count)) { | |
2176 | printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", | |
2177 | task_tgid_vnr(current), current->comm); | |
2178 | printk(KERN_WARNING "Skipping core dump\n"); | |
2179 | goto fail_dropcount; | |
2180 | } | |
2181 | ||
1b0d300b | 2182 | helper_argv = argv_split(GFP_KERNEL, cn.corename+1, NULL); |
350eaf79 TH |
2183 | if (!helper_argv) { |
2184 | printk(KERN_WARNING "%s failed to allocate memory\n", | |
2185 | __func__); | |
a293980c | 2186 | goto fail_dropcount; |
350eaf79 | 2187 | } |
32321137 | 2188 | |
d5bf4c4f ON |
2189 | retval = call_usermodehelper_fns(helper_argv[0], helper_argv, |
2190 | NULL, UMH_WAIT_EXEC, umh_pipe_setup, | |
2191 | NULL, &cprm); | |
2192 | argv_free(helper_argv); | |
2193 | if (retval) { | |
d025c9db | 2194 | printk(KERN_INFO "Core dump to %s pipe failed\n", |
1b0d300b | 2195 | cn.corename); |
d5bf4c4f | 2196 | goto close_fail; |
d025c9db | 2197 | } |
c7135411 ON |
2198 | } else { |
2199 | struct inode *inode; | |
2200 | ||
2201 | if (cprm.limit < binfmt->min_coredump) | |
2202 | goto fail_unlock; | |
2203 | ||
1b0d300b | 2204 | cprm.file = filp_open(cn.corename, |
6d4df677 AD |
2205 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
2206 | 0600); | |
c7135411 ON |
2207 | if (IS_ERR(cprm.file)) |
2208 | goto fail_unlock; | |
1da177e4 | 2209 | |
c7135411 ON |
2210 | inode = cprm.file->f_path.dentry->d_inode; |
2211 | if (inode->i_nlink > 1) | |
2212 | goto close_fail; | |
2213 | if (d_unhashed(cprm.file->f_path.dentry)) | |
2214 | goto close_fail; | |
2215 | /* | |
2216 | * AK: actually i see no reason to not allow this for named | |
2217 | * pipes etc, but keep the previous behaviour for now. | |
2218 | */ | |
2219 | if (!S_ISREG(inode->i_mode)) | |
2220 | goto close_fail; | |
2221 | /* | |
2222 | * Dont allow local users get cute and trick others to coredump | |
2223 | * into their pre-created files. | |
2224 | */ | |
2225 | if (inode->i_uid != current_fsuid()) | |
2226 | goto close_fail; | |
2227 | if (!cprm.file->f_op || !cprm.file->f_op->write) | |
2228 | goto close_fail; | |
2229 | if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file)) | |
2230 | goto close_fail; | |
2231 | } | |
1da177e4 | 2232 | |
c7135411 | 2233 | retval = binfmt->core_dump(&cprm); |
1da177e4 LT |
2234 | if (retval) |
2235 | current->signal->group_exit_code |= 0x80; | |
d5bf4c4f | 2236 | |
61be228a | 2237 | if (ispipe && core_pipe_limit) |
f6151dfe | 2238 | wait_for_dump_helpers(cprm.file); |
d5bf4c4f ON |
2239 | close_fail: |
2240 | if (cprm.file) | |
2241 | filp_close(cprm.file, NULL); | |
a293980c | 2242 | fail_dropcount: |
d5bf4c4f | 2243 | if (ispipe) |
a293980c | 2244 | atomic_dec(&core_dump_count); |
1da177e4 | 2245 | fail_unlock: |
1b0d300b XF |
2246 | kfree(cn.corename); |
2247 | fail_corename: | |
5e43aef5 | 2248 | coredump_finish(mm); |
d84f4f99 | 2249 | revert_creds(old_cred); |
5e43aef5 | 2250 | fail_creds: |
d84f4f99 | 2251 | put_cred(cred); |
1da177e4 | 2252 | fail: |
8cd3ac3a | 2253 | return; |
1da177e4 | 2254 | } |
3aa0ce82 LT |
2255 | |
2256 | /* | |
2257 | * Core dumping helper functions. These are the only things you should | |
2258 | * do on a core-file: use only these functions to write out all the | |
2259 | * necessary info. | |
2260 | */ | |
2261 | int dump_write(struct file *file, const void *addr, int nr) | |
2262 | { | |
2263 | return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr; | |
2264 | } | |
8fd01d6c | 2265 | EXPORT_SYMBOL(dump_write); |
3aa0ce82 LT |
2266 | |
2267 | int dump_seek(struct file *file, loff_t off) | |
2268 | { | |
2269 | int ret = 1; | |
2270 | ||
2271 | if (file->f_op->llseek && file->f_op->llseek != no_llseek) { | |
2272 | if (file->f_op->llseek(file, off, SEEK_CUR) < 0) | |
2273 | return 0; | |
2274 | } else { | |
2275 | char *buf = (char *)get_zeroed_page(GFP_KERNEL); | |
2276 | ||
2277 | if (!buf) | |
2278 | return 0; | |
2279 | while (off > 0) { | |
2280 | unsigned long n = off; | |
2281 | ||
2282 | if (n > PAGE_SIZE) | |
2283 | n = PAGE_SIZE; | |
2284 | if (!dump_write(file, buf, n)) { | |
2285 | ret = 0; | |
2286 | break; | |
2287 | } | |
2288 | off -= n; | |
2289 | } | |
2290 | free_page((unsigned long)buf); | |
2291 | } | |
2292 | return ret; | |
2293 | } | |
8fd01d6c | 2294 | EXPORT_SYMBOL(dump_seek); |