Commit | Line | Data |
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10c28d93 AK |
1 | #include <linux/slab.h> |
2 | #include <linux/file.h> | |
3 | #include <linux/fdtable.h> | |
4 | #include <linux/mm.h> | |
5 | #include <linux/stat.h> | |
6 | #include <linux/fcntl.h> | |
7 | #include <linux/swap.h> | |
8 | #include <linux/string.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/pagemap.h> | |
11 | #include <linux/perf_event.h> | |
12 | #include <linux/highmem.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/key.h> | |
15 | #include <linux/personality.h> | |
16 | #include <linux/binfmts.h> | |
179899fd | 17 | #include <linux/coredump.h> |
10c28d93 AK |
18 | #include <linux/utsname.h> |
19 | #include <linux/pid_namespace.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/namei.h> | |
22 | #include <linux/mount.h> | |
23 | #include <linux/security.h> | |
24 | #include <linux/syscalls.h> | |
25 | #include <linux/tsacct_kern.h> | |
26 | #include <linux/cn_proc.h> | |
27 | #include <linux/audit.h> | |
28 | #include <linux/tracehook.h> | |
29 | #include <linux/kmod.h> | |
30 | #include <linux/fsnotify.h> | |
31 | #include <linux/fs_struct.h> | |
32 | #include <linux/pipe_fs_i.h> | |
33 | #include <linux/oom.h> | |
34 | #include <linux/compat.h> | |
35 | ||
36 | #include <asm/uaccess.h> | |
37 | #include <asm/mmu_context.h> | |
38 | #include <asm/tlb.h> | |
39 | #include <asm/exec.h> | |
40 | ||
41 | #include <trace/events/task.h> | |
42 | #include "internal.h" | |
43 | ||
44 | #include <trace/events/sched.h> | |
45 | ||
46 | int core_uses_pid; | |
10c28d93 | 47 | unsigned int core_pipe_limit; |
3ceadcf6 ON |
48 | char core_pattern[CORENAME_MAX_SIZE] = "core"; |
49 | static int core_name_size = CORENAME_MAX_SIZE; | |
10c28d93 AK |
50 | |
51 | struct core_name { | |
52 | char *corename; | |
53 | int used, size; | |
54 | }; | |
10c28d93 AK |
55 | |
56 | /* The maximal length of core_pattern is also specified in sysctl.c */ | |
57 | ||
3ceadcf6 | 58 | static int expand_corename(struct core_name *cn, int size) |
10c28d93 | 59 | { |
e7fd1549 | 60 | char *corename = krealloc(cn->corename, size, GFP_KERNEL); |
10c28d93 | 61 | |
e7fd1549 | 62 | if (!corename) |
10c28d93 | 63 | return -ENOMEM; |
10c28d93 | 64 | |
3ceadcf6 ON |
65 | if (size > core_name_size) /* racy but harmless */ |
66 | core_name_size = size; | |
67 | ||
68 | cn->size = ksize(corename); | |
e7fd1549 | 69 | cn->corename = corename; |
10c28d93 AK |
70 | return 0; |
71 | } | |
72 | ||
bc03c691 | 73 | static int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg) |
10c28d93 | 74 | { |
5fe9d8ca | 75 | int free, need; |
10c28d93 | 76 | |
5fe9d8ca ON |
77 | again: |
78 | free = cn->size - cn->used; | |
79 | need = vsnprintf(cn->corename + cn->used, free, fmt, arg); | |
80 | if (need < free) { | |
81 | cn->used += need; | |
82 | return 0; | |
83 | } | |
10c28d93 | 84 | |
3ceadcf6 | 85 | if (!expand_corename(cn, cn->size + need - free + 1)) |
5fe9d8ca | 86 | goto again; |
10c28d93 | 87 | |
5fe9d8ca | 88 | return -ENOMEM; |
10c28d93 AK |
89 | } |
90 | ||
bc03c691 ON |
91 | static int cn_printf(struct core_name *cn, const char *fmt, ...) |
92 | { | |
93 | va_list arg; | |
94 | int ret; | |
95 | ||
96 | va_start(arg, fmt); | |
97 | ret = cn_vprintf(cn, fmt, arg); | |
98 | va_end(arg); | |
99 | ||
100 | return ret; | |
101 | } | |
102 | ||
923bed03 | 103 | static int cn_esc_printf(struct core_name *cn, const char *fmt, ...) |
10c28d93 | 104 | { |
923bed03 ON |
105 | int cur = cn->used; |
106 | va_list arg; | |
107 | int ret; | |
108 | ||
109 | va_start(arg, fmt); | |
110 | ret = cn_vprintf(cn, fmt, arg); | |
111 | va_end(arg); | |
112 | ||
113 | for (; cur < cn->used; ++cur) { | |
114 | if (cn->corename[cur] == '/') | |
115 | cn->corename[cur] = '!'; | |
116 | } | |
117 | return ret; | |
10c28d93 AK |
118 | } |
119 | ||
120 | static int cn_print_exe_file(struct core_name *cn) | |
121 | { | |
122 | struct file *exe_file; | |
123 | char *pathbuf, *path; | |
124 | int ret; | |
125 | ||
126 | exe_file = get_mm_exe_file(current->mm); | |
923bed03 ON |
127 | if (!exe_file) |
128 | return cn_esc_printf(cn, "%s (path unknown)", current->comm); | |
10c28d93 AK |
129 | |
130 | pathbuf = kmalloc(PATH_MAX, GFP_TEMPORARY); | |
131 | if (!pathbuf) { | |
132 | ret = -ENOMEM; | |
133 | goto put_exe_file; | |
134 | } | |
135 | ||
136 | path = d_path(&exe_file->f_path, pathbuf, PATH_MAX); | |
137 | if (IS_ERR(path)) { | |
138 | ret = PTR_ERR(path); | |
139 | goto free_buf; | |
140 | } | |
141 | ||
923bed03 | 142 | ret = cn_esc_printf(cn, "%s", path); |
10c28d93 AK |
143 | |
144 | free_buf: | |
145 | kfree(pathbuf); | |
146 | put_exe_file: | |
147 | fput(exe_file); | |
148 | return ret; | |
149 | } | |
150 | ||
151 | /* format_corename will inspect the pattern parameter, and output a | |
152 | * name into corename, which must have space for at least | |
153 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
154 | */ | |
12a2b4b2 | 155 | static int format_corename(struct core_name *cn, struct coredump_params *cprm) |
10c28d93 AK |
156 | { |
157 | const struct cred *cred = current_cred(); | |
158 | const char *pat_ptr = core_pattern; | |
159 | int ispipe = (*pat_ptr == '|'); | |
160 | int pid_in_pattern = 0; | |
161 | int err = 0; | |
162 | ||
e7fd1549 | 163 | cn->used = 0; |
3ceadcf6 ON |
164 | cn->corename = NULL; |
165 | if (expand_corename(cn, core_name_size)) | |
10c28d93 | 166 | return -ENOMEM; |
888ffc59 ON |
167 | cn->corename[0] = '\0'; |
168 | ||
169 | if (ispipe) | |
170 | ++pat_ptr; | |
10c28d93 AK |
171 | |
172 | /* Repeat as long as we have more pattern to process and more output | |
173 | space */ | |
174 | while (*pat_ptr) { | |
175 | if (*pat_ptr != '%') { | |
10c28d93 AK |
176 | err = cn_printf(cn, "%c", *pat_ptr++); |
177 | } else { | |
178 | switch (*++pat_ptr) { | |
179 | /* single % at the end, drop that */ | |
180 | case 0: | |
181 | goto out; | |
182 | /* Double percent, output one percent */ | |
183 | case '%': | |
184 | err = cn_printf(cn, "%c", '%'); | |
185 | break; | |
186 | /* pid */ | |
187 | case 'p': | |
188 | pid_in_pattern = 1; | |
189 | err = cn_printf(cn, "%d", | |
190 | task_tgid_vnr(current)); | |
191 | break; | |
65aafb1e SG |
192 | /* global pid */ |
193 | case 'P': | |
194 | err = cn_printf(cn, "%d", | |
195 | task_tgid_nr(current)); | |
196 | break; | |
10c28d93 AK |
197 | /* uid */ |
198 | case 'u': | |
199 | err = cn_printf(cn, "%d", cred->uid); | |
200 | break; | |
201 | /* gid */ | |
202 | case 'g': | |
203 | err = cn_printf(cn, "%d", cred->gid); | |
204 | break; | |
12a2b4b2 ON |
205 | case 'd': |
206 | err = cn_printf(cn, "%d", | |
207 | __get_dumpable(cprm->mm_flags)); | |
208 | break; | |
10c28d93 AK |
209 | /* signal that caused the coredump */ |
210 | case 's': | |
5ab1c309 | 211 | err = cn_printf(cn, "%ld", cprm->siginfo->si_signo); |
10c28d93 AK |
212 | break; |
213 | /* UNIX time of coredump */ | |
214 | case 't': { | |
215 | struct timeval tv; | |
216 | do_gettimeofday(&tv); | |
217 | err = cn_printf(cn, "%lu", tv.tv_sec); | |
218 | break; | |
219 | } | |
220 | /* hostname */ | |
923bed03 | 221 | case 'h': |
10c28d93 | 222 | down_read(&uts_sem); |
923bed03 | 223 | err = cn_esc_printf(cn, "%s", |
10c28d93 AK |
224 | utsname()->nodename); |
225 | up_read(&uts_sem); | |
10c28d93 | 226 | break; |
10c28d93 | 227 | /* executable */ |
923bed03 ON |
228 | case 'e': |
229 | err = cn_esc_printf(cn, "%s", current->comm); | |
10c28d93 | 230 | break; |
10c28d93 AK |
231 | case 'E': |
232 | err = cn_print_exe_file(cn); | |
233 | break; | |
234 | /* core limit size */ | |
235 | case 'c': | |
236 | err = cn_printf(cn, "%lu", | |
237 | rlimit(RLIMIT_CORE)); | |
238 | break; | |
239 | default: | |
240 | break; | |
241 | } | |
242 | ++pat_ptr; | |
243 | } | |
244 | ||
245 | if (err) | |
246 | return err; | |
247 | } | |
248 | ||
888ffc59 | 249 | out: |
10c28d93 AK |
250 | /* Backward compatibility with core_uses_pid: |
251 | * | |
252 | * If core_pattern does not include a %p (as is the default) | |
253 | * and core_uses_pid is set, then .%pid will be appended to | |
254 | * the filename. Do not do this for piped commands. */ | |
255 | if (!ispipe && !pid_in_pattern && core_uses_pid) { | |
256 | err = cn_printf(cn, ".%d", task_tgid_vnr(current)); | |
257 | if (err) | |
258 | return err; | |
259 | } | |
10c28d93 AK |
260 | return ispipe; |
261 | } | |
262 | ||
263 | static int zap_process(struct task_struct *start, int exit_code) | |
264 | { | |
265 | struct task_struct *t; | |
266 | int nr = 0; | |
267 | ||
10c28d93 AK |
268 | start->signal->group_exit_code = exit_code; |
269 | start->signal->group_stop_count = 0; | |
270 | ||
271 | t = start; | |
272 | do { | |
273 | task_clear_jobctl_pending(t, JOBCTL_PENDING_MASK); | |
274 | if (t != current && t->mm) { | |
275 | sigaddset(&t->pending.signal, SIGKILL); | |
276 | signal_wake_up(t, 1); | |
277 | nr++; | |
278 | } | |
279 | } while_each_thread(start, t); | |
280 | ||
281 | return nr; | |
282 | } | |
283 | ||
403bad72 ON |
284 | static int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
285 | struct core_state *core_state, int exit_code) | |
10c28d93 AK |
286 | { |
287 | struct task_struct *g, *p; | |
288 | unsigned long flags; | |
289 | int nr = -EAGAIN; | |
290 | ||
291 | spin_lock_irq(&tsk->sighand->siglock); | |
292 | if (!signal_group_exit(tsk->signal)) { | |
293 | mm->core_state = core_state; | |
294 | nr = zap_process(tsk, exit_code); | |
6cd8f0ac | 295 | tsk->signal->group_exit_task = tsk; |
403bad72 | 296 | /* ignore all signals except SIGKILL, see prepare_signal() */ |
6cd8f0ac | 297 | tsk->signal->flags = SIGNAL_GROUP_COREDUMP; |
403bad72 | 298 | clear_tsk_thread_flag(tsk, TIF_SIGPENDING); |
10c28d93 AK |
299 | } |
300 | spin_unlock_irq(&tsk->sighand->siglock); | |
301 | if (unlikely(nr < 0)) | |
302 | return nr; | |
303 | ||
079148b9 | 304 | tsk->flags = PF_DUMPCORE; |
10c28d93 AK |
305 | if (atomic_read(&mm->mm_users) == nr + 1) |
306 | goto done; | |
307 | /* | |
308 | * We should find and kill all tasks which use this mm, and we should | |
309 | * count them correctly into ->nr_threads. We don't take tasklist | |
310 | * lock, but this is safe wrt: | |
311 | * | |
312 | * fork: | |
313 | * None of sub-threads can fork after zap_process(leader). All | |
314 | * processes which were created before this point should be | |
315 | * visible to zap_threads() because copy_process() adds the new | |
316 | * process to the tail of init_task.tasks list, and lock/unlock | |
317 | * of ->siglock provides a memory barrier. | |
318 | * | |
319 | * do_exit: | |
320 | * The caller holds mm->mmap_sem. This means that the task which | |
321 | * uses this mm can't pass exit_mm(), so it can't exit or clear | |
322 | * its ->mm. | |
323 | * | |
324 | * de_thread: | |
325 | * It does list_replace_rcu(&leader->tasks, ¤t->tasks), | |
326 | * we must see either old or new leader, this does not matter. | |
327 | * However, it can change p->sighand, so lock_task_sighand(p) | |
328 | * must be used. Since p->mm != NULL and we hold ->mmap_sem | |
329 | * it can't fail. | |
330 | * | |
331 | * Note also that "g" can be the old leader with ->mm == NULL | |
332 | * and already unhashed and thus removed from ->thread_group. | |
333 | * This is OK, __unhash_process()->list_del_rcu() does not | |
334 | * clear the ->next pointer, we will find the new leader via | |
335 | * next_thread(). | |
336 | */ | |
337 | rcu_read_lock(); | |
338 | for_each_process(g) { | |
339 | if (g == tsk->group_leader) | |
340 | continue; | |
341 | if (g->flags & PF_KTHREAD) | |
342 | continue; | |
343 | p = g; | |
344 | do { | |
345 | if (p->mm) { | |
346 | if (unlikely(p->mm == mm)) { | |
347 | lock_task_sighand(p, &flags); | |
348 | nr += zap_process(p, exit_code); | |
6cd8f0ac | 349 | p->signal->flags = SIGNAL_GROUP_EXIT; |
10c28d93 AK |
350 | unlock_task_sighand(p, &flags); |
351 | } | |
352 | break; | |
353 | } | |
354 | } while_each_thread(g, p); | |
355 | } | |
356 | rcu_read_unlock(); | |
357 | done: | |
358 | atomic_set(&core_state->nr_threads, nr); | |
359 | return nr; | |
360 | } | |
361 | ||
362 | static int coredump_wait(int exit_code, struct core_state *core_state) | |
363 | { | |
364 | struct task_struct *tsk = current; | |
365 | struct mm_struct *mm = tsk->mm; | |
366 | int core_waiters = -EBUSY; | |
367 | ||
368 | init_completion(&core_state->startup); | |
369 | core_state->dumper.task = tsk; | |
370 | core_state->dumper.next = NULL; | |
371 | ||
372 | down_write(&mm->mmap_sem); | |
373 | if (!mm->core_state) | |
374 | core_waiters = zap_threads(tsk, mm, core_state, exit_code); | |
375 | up_write(&mm->mmap_sem); | |
376 | ||
377 | if (core_waiters > 0) { | |
378 | struct core_thread *ptr; | |
379 | ||
380 | wait_for_completion(&core_state->startup); | |
381 | /* | |
382 | * Wait for all the threads to become inactive, so that | |
383 | * all the thread context (extended register state, like | |
384 | * fpu etc) gets copied to the memory. | |
385 | */ | |
386 | ptr = core_state->dumper.next; | |
387 | while (ptr != NULL) { | |
388 | wait_task_inactive(ptr->task, 0); | |
389 | ptr = ptr->next; | |
390 | } | |
391 | } | |
392 | ||
393 | return core_waiters; | |
394 | } | |
395 | ||
acdedd99 | 396 | static void coredump_finish(struct mm_struct *mm, bool core_dumped) |
10c28d93 AK |
397 | { |
398 | struct core_thread *curr, *next; | |
399 | struct task_struct *task; | |
400 | ||
6cd8f0ac | 401 | spin_lock_irq(¤t->sighand->siglock); |
acdedd99 ON |
402 | if (core_dumped && !__fatal_signal_pending(current)) |
403 | current->signal->group_exit_code |= 0x80; | |
6cd8f0ac ON |
404 | current->signal->group_exit_task = NULL; |
405 | current->signal->flags = SIGNAL_GROUP_EXIT; | |
406 | spin_unlock_irq(¤t->sighand->siglock); | |
407 | ||
10c28d93 AK |
408 | next = mm->core_state->dumper.next; |
409 | while ((curr = next) != NULL) { | |
410 | next = curr->next; | |
411 | task = curr->task; | |
412 | /* | |
413 | * see exit_mm(), curr->task must not see | |
414 | * ->task == NULL before we read ->next. | |
415 | */ | |
416 | smp_mb(); | |
417 | curr->task = NULL; | |
418 | wake_up_process(task); | |
419 | } | |
420 | ||
421 | mm->core_state = NULL; | |
422 | } | |
423 | ||
528f827e ON |
424 | static bool dump_interrupted(void) |
425 | { | |
426 | /* | |
427 | * SIGKILL or freezing() interrupt the coredumping. Perhaps we | |
428 | * can do try_to_freeze() and check __fatal_signal_pending(), | |
429 | * but then we need to teach dump_write() to restart and clear | |
430 | * TIF_SIGPENDING. | |
431 | */ | |
432 | return signal_pending(current); | |
433 | } | |
434 | ||
10c28d93 AK |
435 | static void wait_for_dump_helpers(struct file *file) |
436 | { | |
de32ec4c | 437 | struct pipe_inode_info *pipe = file->private_data; |
10c28d93 AK |
438 | |
439 | pipe_lock(pipe); | |
440 | pipe->readers++; | |
441 | pipe->writers--; | |
dc7ee2aa ON |
442 | wake_up_interruptible_sync(&pipe->wait); |
443 | kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); | |
444 | pipe_unlock(pipe); | |
10c28d93 | 445 | |
dc7ee2aa ON |
446 | /* |
447 | * We actually want wait_event_freezable() but then we need | |
448 | * to clear TIF_SIGPENDING and improve dump_interrupted(). | |
449 | */ | |
450 | wait_event_interruptible(pipe->wait, pipe->readers == 1); | |
10c28d93 | 451 | |
dc7ee2aa | 452 | pipe_lock(pipe); |
10c28d93 AK |
453 | pipe->readers--; |
454 | pipe->writers++; | |
455 | pipe_unlock(pipe); | |
10c28d93 AK |
456 | } |
457 | ||
458 | /* | |
459 | * umh_pipe_setup | |
460 | * helper function to customize the process used | |
461 | * to collect the core in userspace. Specifically | |
462 | * it sets up a pipe and installs it as fd 0 (stdin) | |
463 | * for the process. Returns 0 on success, or | |
464 | * PTR_ERR on failure. | |
465 | * Note that it also sets the core limit to 1. This | |
466 | * is a special value that we use to trap recursive | |
467 | * core dumps | |
468 | */ | |
469 | static int umh_pipe_setup(struct subprocess_info *info, struct cred *new) | |
470 | { | |
471 | struct file *files[2]; | |
472 | struct coredump_params *cp = (struct coredump_params *)info->data; | |
473 | int err = create_pipe_files(files, 0); | |
474 | if (err) | |
475 | return err; | |
476 | ||
477 | cp->file = files[1]; | |
478 | ||
45525b26 AV |
479 | err = replace_fd(0, files[0], 0); |
480 | fput(files[0]); | |
10c28d93 AK |
481 | /* and disallow core files too */ |
482 | current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1}; | |
483 | ||
45525b26 | 484 | return err; |
10c28d93 AK |
485 | } |
486 | ||
ec57941e | 487 | void do_coredump(const siginfo_t *siginfo) |
10c28d93 AK |
488 | { |
489 | struct core_state core_state; | |
490 | struct core_name cn; | |
491 | struct mm_struct *mm = current->mm; | |
492 | struct linux_binfmt * binfmt; | |
493 | const struct cred *old_cred; | |
494 | struct cred *cred; | |
495 | int retval = 0; | |
496 | int flag = 0; | |
497 | int ispipe; | |
498 | struct files_struct *displaced; | |
499 | bool need_nonrelative = false; | |
acdedd99 | 500 | bool core_dumped = false; |
10c28d93 AK |
501 | static atomic_t core_dump_count = ATOMIC_INIT(0); |
502 | struct coredump_params cprm = { | |
5ab1c309 | 503 | .siginfo = siginfo, |
541880d9 | 504 | .regs = signal_pt_regs(), |
10c28d93 AK |
505 | .limit = rlimit(RLIMIT_CORE), |
506 | /* | |
507 | * We must use the same mm->flags while dumping core to avoid | |
508 | * inconsistency of bit flags, since this flag is not protected | |
509 | * by any locks. | |
510 | */ | |
511 | .mm_flags = mm->flags, | |
512 | }; | |
513 | ||
5ab1c309 | 514 | audit_core_dumps(siginfo->si_signo); |
10c28d93 AK |
515 | |
516 | binfmt = mm->binfmt; | |
517 | if (!binfmt || !binfmt->core_dump) | |
518 | goto fail; | |
519 | if (!__get_dumpable(cprm.mm_flags)) | |
520 | goto fail; | |
521 | ||
522 | cred = prepare_creds(); | |
523 | if (!cred) | |
524 | goto fail; | |
525 | /* | |
526 | * We cannot trust fsuid as being the "true" uid of the process | |
527 | * nor do we know its entire history. We only know it was tainted | |
528 | * so we dump it as root in mode 2, and only into a controlled | |
529 | * environment (pipe handler or fully qualified path). | |
530 | */ | |
e579d2c2 | 531 | if (__get_dumpable(cprm.mm_flags) == SUID_DUMP_ROOT) { |
10c28d93 AK |
532 | /* Setuid core dump mode */ |
533 | flag = O_EXCL; /* Stop rewrite attacks */ | |
534 | cred->fsuid = GLOBAL_ROOT_UID; /* Dump root private */ | |
535 | need_nonrelative = true; | |
536 | } | |
537 | ||
5ab1c309 | 538 | retval = coredump_wait(siginfo->si_signo, &core_state); |
10c28d93 AK |
539 | if (retval < 0) |
540 | goto fail_creds; | |
541 | ||
542 | old_cred = override_creds(cred); | |
543 | ||
12a2b4b2 | 544 | ispipe = format_corename(&cn, &cprm); |
10c28d93 | 545 | |
fb96c475 | 546 | if (ispipe) { |
10c28d93 AK |
547 | int dump_count; |
548 | char **helper_argv; | |
907ed132 | 549 | struct subprocess_info *sub_info; |
10c28d93 AK |
550 | |
551 | if (ispipe < 0) { | |
552 | printk(KERN_WARNING "format_corename failed\n"); | |
553 | printk(KERN_WARNING "Aborting core\n"); | |
e7fd1549 | 554 | goto fail_unlock; |
10c28d93 AK |
555 | } |
556 | ||
557 | if (cprm.limit == 1) { | |
558 | /* See umh_pipe_setup() which sets RLIMIT_CORE = 1. | |
559 | * | |
560 | * Normally core limits are irrelevant to pipes, since | |
561 | * we're not writing to the file system, but we use | |
562 | * cprm.limit of 1 here as a speacial value, this is a | |
563 | * consistent way to catch recursive crashes. | |
564 | * We can still crash if the core_pattern binary sets | |
565 | * RLIM_CORE = !1, but it runs as root, and can do | |
566 | * lots of stupid things. | |
567 | * | |
568 | * Note that we use task_tgid_vnr here to grab the pid | |
569 | * of the process group leader. That way we get the | |
570 | * right pid if a thread in a multi-threaded | |
571 | * core_pattern process dies. | |
572 | */ | |
573 | printk(KERN_WARNING | |
574 | "Process %d(%s) has RLIMIT_CORE set to 1\n", | |
575 | task_tgid_vnr(current), current->comm); | |
576 | printk(KERN_WARNING "Aborting core\n"); | |
577 | goto fail_unlock; | |
578 | } | |
579 | cprm.limit = RLIM_INFINITY; | |
580 | ||
581 | dump_count = atomic_inc_return(&core_dump_count); | |
582 | if (core_pipe_limit && (core_pipe_limit < dump_count)) { | |
583 | printk(KERN_WARNING "Pid %d(%s) over core_pipe_limit\n", | |
584 | task_tgid_vnr(current), current->comm); | |
585 | printk(KERN_WARNING "Skipping core dump\n"); | |
586 | goto fail_dropcount; | |
587 | } | |
588 | ||
888ffc59 | 589 | helper_argv = argv_split(GFP_KERNEL, cn.corename, NULL); |
10c28d93 AK |
590 | if (!helper_argv) { |
591 | printk(KERN_WARNING "%s failed to allocate memory\n", | |
592 | __func__); | |
593 | goto fail_dropcount; | |
594 | } | |
595 | ||
907ed132 LDM |
596 | retval = -ENOMEM; |
597 | sub_info = call_usermodehelper_setup(helper_argv[0], | |
598 | helper_argv, NULL, GFP_KERNEL, | |
599 | umh_pipe_setup, NULL, &cprm); | |
600 | if (sub_info) | |
601 | retval = call_usermodehelper_exec(sub_info, | |
602 | UMH_WAIT_EXEC); | |
603 | ||
10c28d93 AK |
604 | argv_free(helper_argv); |
605 | if (retval) { | |
888ffc59 | 606 | printk(KERN_INFO "Core dump to |%s pipe failed\n", |
10c28d93 AK |
607 | cn.corename); |
608 | goto close_fail; | |
fb96c475 | 609 | } |
10c28d93 AK |
610 | } else { |
611 | struct inode *inode; | |
612 | ||
613 | if (cprm.limit < binfmt->min_coredump) | |
614 | goto fail_unlock; | |
615 | ||
616 | if (need_nonrelative && cn.corename[0] != '/') { | |
617 | printk(KERN_WARNING "Pid %d(%s) can only dump core "\ | |
618 | "to fully qualified path!\n", | |
619 | task_tgid_vnr(current), current->comm); | |
620 | printk(KERN_WARNING "Skipping core dump\n"); | |
621 | goto fail_unlock; | |
622 | } | |
623 | ||
624 | cprm.file = filp_open(cn.corename, | |
625 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, | |
626 | 0600); | |
627 | if (IS_ERR(cprm.file)) | |
628 | goto fail_unlock; | |
629 | ||
496ad9aa | 630 | inode = file_inode(cprm.file); |
10c28d93 AK |
631 | if (inode->i_nlink > 1) |
632 | goto close_fail; | |
633 | if (d_unhashed(cprm.file->f_path.dentry)) | |
634 | goto close_fail; | |
635 | /* | |
636 | * AK: actually i see no reason to not allow this for named | |
637 | * pipes etc, but keep the previous behaviour for now. | |
638 | */ | |
639 | if (!S_ISREG(inode->i_mode)) | |
640 | goto close_fail; | |
641 | /* | |
642 | * Dont allow local users get cute and trick others to coredump | |
643 | * into their pre-created files. | |
644 | */ | |
645 | if (!uid_eq(inode->i_uid, current_fsuid())) | |
646 | goto close_fail; | |
72c2d531 | 647 | if (!cprm.file->f_op->write) |
10c28d93 AK |
648 | goto close_fail; |
649 | if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file)) | |
650 | goto close_fail; | |
651 | } | |
652 | ||
653 | /* get us an unshared descriptor table; almost always a no-op */ | |
654 | retval = unshare_files(&displaced); | |
655 | if (retval) | |
656 | goto close_fail; | |
657 | if (displaced) | |
658 | put_files_struct(displaced); | |
e86d35c3 AV |
659 | if (!dump_interrupted()) { |
660 | file_start_write(cprm.file); | |
661 | core_dumped = binfmt->core_dump(&cprm); | |
662 | file_end_write(cprm.file); | |
663 | } | |
10c28d93 AK |
664 | if (ispipe && core_pipe_limit) |
665 | wait_for_dump_helpers(cprm.file); | |
666 | close_fail: | |
667 | if (cprm.file) | |
668 | filp_close(cprm.file, NULL); | |
669 | fail_dropcount: | |
670 | if (ispipe) | |
671 | atomic_dec(&core_dump_count); | |
672 | fail_unlock: | |
673 | kfree(cn.corename); | |
acdedd99 | 674 | coredump_finish(mm, core_dumped); |
10c28d93 AK |
675 | revert_creds(old_cred); |
676 | fail_creds: | |
677 | put_cred(cred); | |
678 | fail: | |
679 | return; | |
680 | } | |
681 | ||
682 | /* | |
683 | * Core dumping helper functions. These are the only things you should | |
684 | * do on a core-file: use only these functions to write out all the | |
685 | * necessary info. | |
686 | */ | |
ecc8c772 AV |
687 | int dump_emit(struct coredump_params *cprm, const void *addr, int nr) |
688 | { | |
689 | struct file *file = cprm->file; | |
2507a4fb AV |
690 | loff_t pos = file->f_pos; |
691 | ssize_t n; | |
ecc8c772 AV |
692 | if (cprm->written + nr > cprm->limit) |
693 | return 0; | |
2507a4fb AV |
694 | while (nr) { |
695 | if (dump_interrupted()) | |
696 | return 0; | |
52da40ae | 697 | n = __kernel_write(file, addr, nr, &pos); |
2507a4fb AV |
698 | if (n <= 0) |
699 | return 0; | |
700 | file->f_pos = pos; | |
701 | cprm->written += n; | |
702 | nr -= n; | |
703 | } | |
ecc8c772 AV |
704 | return 1; |
705 | } | |
706 | EXPORT_SYMBOL(dump_emit); | |
707 | ||
9b56d543 | 708 | int dump_skip(struct coredump_params *cprm, size_t nr) |
10c28d93 | 709 | { |
9b56d543 AV |
710 | static char zeroes[PAGE_SIZE]; |
711 | struct file *file = cprm->file; | |
10c28d93 | 712 | if (file->f_op->llseek && file->f_op->llseek != no_llseek) { |
9b56d543 AV |
713 | if (cprm->written + nr > cprm->limit) |
714 | return 0; | |
528f827e | 715 | if (dump_interrupted() || |
9b56d543 | 716 | file->f_op->llseek(file, nr, SEEK_CUR) < 0) |
10c28d93 | 717 | return 0; |
9b56d543 AV |
718 | cprm->written += nr; |
719 | return 1; | |
10c28d93 | 720 | } else { |
9b56d543 AV |
721 | while (nr > PAGE_SIZE) { |
722 | if (!dump_emit(cprm, zeroes, PAGE_SIZE)) | |
723 | return 0; | |
724 | nr -= PAGE_SIZE; | |
10c28d93 | 725 | } |
9b56d543 | 726 | return dump_emit(cprm, zeroes, nr); |
10c28d93 | 727 | } |
10c28d93 | 728 | } |
9b56d543 | 729 | EXPORT_SYMBOL(dump_skip); |
22a8cb82 AV |
730 | |
731 | int dump_align(struct coredump_params *cprm, int align) | |
732 | { | |
733 | unsigned mod = cprm->written & (align - 1); | |
734 | if (align & (align - 1)) | |
db51242d AV |
735 | return 0; |
736 | return mod ? dump_skip(cprm, align - mod) : 1; | |
22a8cb82 AV |
737 | } |
738 | EXPORT_SYMBOL(dump_align); |