Commit | Line | Data |
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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 | ||
25 | #include <linux/config.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/file.h> | |
28 | #include <linux/mman.h> | |
29 | #include <linux/a.out.h> | |
30 | #include <linux/stat.h> | |
31 | #include <linux/fcntl.h> | |
32 | #include <linux/smp_lock.h> | |
33 | #include <linux/init.h> | |
34 | #include <linux/pagemap.h> | |
35 | #include <linux/highmem.h> | |
36 | #include <linux/spinlock.h> | |
37 | #include <linux/key.h> | |
38 | #include <linux/personality.h> | |
39 | #include <linux/binfmts.h> | |
40 | #include <linux/swap.h> | |
41 | #include <linux/utsname.h> | |
42 | #include <linux/module.h> | |
43 | #include <linux/namei.h> | |
44 | #include <linux/proc_fs.h> | |
45 | #include <linux/ptrace.h> | |
46 | #include <linux/mount.h> | |
47 | #include <linux/security.h> | |
48 | #include <linux/syscalls.h> | |
49 | #include <linux/rmap.h> | |
50 | #include <linux/acct.h> | |
51 | ||
52 | #include <asm/uaccess.h> | |
53 | #include <asm/mmu_context.h> | |
54 | ||
55 | #ifdef CONFIG_KMOD | |
56 | #include <linux/kmod.h> | |
57 | #endif | |
58 | ||
59 | int core_uses_pid; | |
60 | char core_pattern[65] = "core"; | |
61 | /* The maximal length of core_pattern is also specified in sysctl.c */ | |
62 | ||
63 | static struct linux_binfmt *formats; | |
64 | static DEFINE_RWLOCK(binfmt_lock); | |
65 | ||
66 | int register_binfmt(struct linux_binfmt * fmt) | |
67 | { | |
68 | struct linux_binfmt ** tmp = &formats; | |
69 | ||
70 | if (!fmt) | |
71 | return -EINVAL; | |
72 | if (fmt->next) | |
73 | return -EBUSY; | |
74 | write_lock(&binfmt_lock); | |
75 | while (*tmp) { | |
76 | if (fmt == *tmp) { | |
77 | write_unlock(&binfmt_lock); | |
78 | return -EBUSY; | |
79 | } | |
80 | tmp = &(*tmp)->next; | |
81 | } | |
82 | fmt->next = formats; | |
83 | formats = fmt; | |
84 | write_unlock(&binfmt_lock); | |
85 | return 0; | |
86 | } | |
87 | ||
88 | EXPORT_SYMBOL(register_binfmt); | |
89 | ||
90 | int unregister_binfmt(struct linux_binfmt * fmt) | |
91 | { | |
92 | struct linux_binfmt ** tmp = &formats; | |
93 | ||
94 | write_lock(&binfmt_lock); | |
95 | while (*tmp) { | |
96 | if (fmt == *tmp) { | |
97 | *tmp = fmt->next; | |
98 | write_unlock(&binfmt_lock); | |
99 | return 0; | |
100 | } | |
101 | tmp = &(*tmp)->next; | |
102 | } | |
103 | write_unlock(&binfmt_lock); | |
104 | return -EINVAL; | |
105 | } | |
106 | ||
107 | EXPORT_SYMBOL(unregister_binfmt); | |
108 | ||
109 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
110 | { | |
111 | module_put(fmt->module); | |
112 | } | |
113 | ||
114 | /* | |
115 | * Note that a shared library must be both readable and executable due to | |
116 | * security reasons. | |
117 | * | |
118 | * Also note that we take the address to load from from the file itself. | |
119 | */ | |
120 | asmlinkage long sys_uselib(const char __user * library) | |
121 | { | |
122 | struct file * file; | |
123 | struct nameidata nd; | |
124 | int error; | |
125 | ||
126 | nd.intent.open.flags = FMODE_READ; | |
127 | error = __user_walk(library, LOOKUP_FOLLOW|LOOKUP_OPEN, &nd); | |
128 | if (error) | |
129 | goto out; | |
130 | ||
131 | error = -EINVAL; | |
132 | if (!S_ISREG(nd.dentry->d_inode->i_mode)) | |
133 | goto exit; | |
134 | ||
135 | error = permission(nd.dentry->d_inode, MAY_READ | MAY_EXEC, &nd); | |
136 | if (error) | |
137 | goto exit; | |
138 | ||
139 | file = dentry_open(nd.dentry, nd.mnt, O_RDONLY); | |
140 | error = PTR_ERR(file); | |
141 | if (IS_ERR(file)) | |
142 | goto out; | |
143 | ||
144 | error = -ENOEXEC; | |
145 | if(file->f_op) { | |
146 | struct linux_binfmt * fmt; | |
147 | ||
148 | read_lock(&binfmt_lock); | |
149 | for (fmt = formats ; fmt ; fmt = fmt->next) { | |
150 | if (!fmt->load_shlib) | |
151 | continue; | |
152 | if (!try_module_get(fmt->module)) | |
153 | continue; | |
154 | read_unlock(&binfmt_lock); | |
155 | error = fmt->load_shlib(file); | |
156 | read_lock(&binfmt_lock); | |
157 | put_binfmt(fmt); | |
158 | if (error != -ENOEXEC) | |
159 | break; | |
160 | } | |
161 | read_unlock(&binfmt_lock); | |
162 | } | |
163 | fput(file); | |
164 | out: | |
165 | return error; | |
166 | exit: | |
167 | path_release(&nd); | |
168 | goto out; | |
169 | } | |
170 | ||
171 | /* | |
172 | * count() counts the number of strings in array ARGV. | |
173 | */ | |
174 | static int count(char __user * __user * argv, int max) | |
175 | { | |
176 | int i = 0; | |
177 | ||
178 | if (argv != NULL) { | |
179 | for (;;) { | |
180 | char __user * p; | |
181 | ||
182 | if (get_user(p, argv)) | |
183 | return -EFAULT; | |
184 | if (!p) | |
185 | break; | |
186 | argv++; | |
187 | if(++i > max) | |
188 | return -E2BIG; | |
189 | cond_resched(); | |
190 | } | |
191 | } | |
192 | return i; | |
193 | } | |
194 | ||
195 | /* | |
196 | * 'copy_strings()' copies argument/environment strings from user | |
197 | * memory to free pages in kernel mem. These are in a format ready | |
198 | * to be put directly into the top of new user memory. | |
199 | */ | |
200 | int copy_strings(int argc,char __user * __user * argv, struct linux_binprm *bprm) | |
201 | { | |
202 | struct page *kmapped_page = NULL; | |
203 | char *kaddr = NULL; | |
204 | int ret; | |
205 | ||
206 | while (argc-- > 0) { | |
207 | char __user *str; | |
208 | int len; | |
209 | unsigned long pos; | |
210 | ||
211 | if (get_user(str, argv+argc) || | |
212 | !(len = strnlen_user(str, bprm->p))) { | |
213 | ret = -EFAULT; | |
214 | goto out; | |
215 | } | |
216 | ||
217 | if (bprm->p < len) { | |
218 | ret = -E2BIG; | |
219 | goto out; | |
220 | } | |
221 | ||
222 | bprm->p -= len; | |
223 | /* XXX: add architecture specific overflow check here. */ | |
224 | pos = bprm->p; | |
225 | ||
226 | while (len > 0) { | |
227 | int i, new, err; | |
228 | int offset, bytes_to_copy; | |
229 | struct page *page; | |
230 | ||
231 | offset = pos % PAGE_SIZE; | |
232 | i = pos/PAGE_SIZE; | |
233 | page = bprm->page[i]; | |
234 | new = 0; | |
235 | if (!page) { | |
236 | page = alloc_page(GFP_HIGHUSER); | |
237 | bprm->page[i] = page; | |
238 | if (!page) { | |
239 | ret = -ENOMEM; | |
240 | goto out; | |
241 | } | |
242 | new = 1; | |
243 | } | |
244 | ||
245 | if (page != kmapped_page) { | |
246 | if (kmapped_page) | |
247 | kunmap(kmapped_page); | |
248 | kmapped_page = page; | |
249 | kaddr = kmap(kmapped_page); | |
250 | } | |
251 | if (new && offset) | |
252 | memset(kaddr, 0, offset); | |
253 | bytes_to_copy = PAGE_SIZE - offset; | |
254 | if (bytes_to_copy > len) { | |
255 | bytes_to_copy = len; | |
256 | if (new) | |
257 | memset(kaddr+offset+len, 0, | |
258 | PAGE_SIZE-offset-len); | |
259 | } | |
260 | err = copy_from_user(kaddr+offset, str, bytes_to_copy); | |
261 | if (err) { | |
262 | ret = -EFAULT; | |
263 | goto out; | |
264 | } | |
265 | ||
266 | pos += bytes_to_copy; | |
267 | str += bytes_to_copy; | |
268 | len -= bytes_to_copy; | |
269 | } | |
270 | } | |
271 | ret = 0; | |
272 | out: | |
273 | if (kmapped_page) | |
274 | kunmap(kmapped_page); | |
275 | return ret; | |
276 | } | |
277 | ||
278 | /* | |
279 | * Like copy_strings, but get argv and its values from kernel memory. | |
280 | */ | |
281 | int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) | |
282 | { | |
283 | int r; | |
284 | mm_segment_t oldfs = get_fs(); | |
285 | set_fs(KERNEL_DS); | |
286 | r = copy_strings(argc, (char __user * __user *)argv, bprm); | |
287 | set_fs(oldfs); | |
288 | return r; | |
289 | } | |
290 | ||
291 | EXPORT_SYMBOL(copy_strings_kernel); | |
292 | ||
293 | #ifdef CONFIG_MMU | |
294 | /* | |
295 | * This routine is used to map in a page into an address space: needed by | |
296 | * execve() for the initial stack and environment pages. | |
297 | * | |
298 | * vma->vm_mm->mmap_sem is held for writing. | |
299 | */ | |
300 | void install_arg_page(struct vm_area_struct *vma, | |
301 | struct page *page, unsigned long address) | |
302 | { | |
303 | struct mm_struct *mm = vma->vm_mm; | |
304 | pgd_t * pgd; | |
305 | pud_t * pud; | |
306 | pmd_t * pmd; | |
307 | pte_t * pte; | |
308 | ||
309 | if (unlikely(anon_vma_prepare(vma))) | |
310 | goto out_sig; | |
311 | ||
312 | flush_dcache_page(page); | |
313 | pgd = pgd_offset(mm, address); | |
314 | ||
315 | spin_lock(&mm->page_table_lock); | |
316 | pud = pud_alloc(mm, pgd, address); | |
317 | if (!pud) | |
318 | goto out; | |
319 | pmd = pmd_alloc(mm, pud, address); | |
320 | if (!pmd) | |
321 | goto out; | |
322 | pte = pte_alloc_map(mm, pmd, address); | |
323 | if (!pte) | |
324 | goto out; | |
325 | if (!pte_none(*pte)) { | |
326 | pte_unmap(pte); | |
327 | goto out; | |
328 | } | |
329 | inc_mm_counter(mm, rss); | |
330 | lru_cache_add_active(page); | |
331 | set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte( | |
332 | page, vma->vm_page_prot)))); | |
333 | page_add_anon_rmap(page, vma, address); | |
334 | pte_unmap(pte); | |
335 | spin_unlock(&mm->page_table_lock); | |
336 | ||
337 | /* no need for flush_tlb */ | |
338 | return; | |
339 | out: | |
340 | spin_unlock(&mm->page_table_lock); | |
341 | out_sig: | |
342 | __free_page(page); | |
343 | force_sig(SIGKILL, current); | |
344 | } | |
345 | ||
346 | #define EXTRA_STACK_VM_PAGES 20 /* random */ | |
347 | ||
348 | int setup_arg_pages(struct linux_binprm *bprm, | |
349 | unsigned long stack_top, | |
350 | int executable_stack) | |
351 | { | |
352 | unsigned long stack_base; | |
353 | struct vm_area_struct *mpnt; | |
354 | struct mm_struct *mm = current->mm; | |
355 | int i, ret; | |
356 | long arg_size; | |
357 | ||
358 | #ifdef CONFIG_STACK_GROWSUP | |
359 | /* Move the argument and environment strings to the bottom of the | |
360 | * stack space. | |
361 | */ | |
362 | int offset, j; | |
363 | char *to, *from; | |
364 | ||
365 | /* Start by shifting all the pages down */ | |
366 | i = 0; | |
367 | for (j = 0; j < MAX_ARG_PAGES; j++) { | |
368 | struct page *page = bprm->page[j]; | |
369 | if (!page) | |
370 | continue; | |
371 | bprm->page[i++] = page; | |
372 | } | |
373 | ||
374 | /* Now move them within their pages */ | |
375 | offset = bprm->p % PAGE_SIZE; | |
376 | to = kmap(bprm->page[0]); | |
377 | for (j = 1; j < i; j++) { | |
378 | memmove(to, to + offset, PAGE_SIZE - offset); | |
379 | from = kmap(bprm->page[j]); | |
380 | memcpy(to + PAGE_SIZE - offset, from, offset); | |
381 | kunmap(bprm->page[j - 1]); | |
382 | to = from; | |
383 | } | |
384 | memmove(to, to + offset, PAGE_SIZE - offset); | |
385 | kunmap(bprm->page[j - 1]); | |
386 | ||
387 | /* Limit stack size to 1GB */ | |
388 | stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max; | |
389 | if (stack_base > (1 << 30)) | |
390 | stack_base = 1 << 30; | |
391 | stack_base = PAGE_ALIGN(stack_top - stack_base); | |
392 | ||
393 | /* Adjust bprm->p to point to the end of the strings. */ | |
394 | bprm->p = stack_base + PAGE_SIZE * i - offset; | |
395 | ||
396 | mm->arg_start = stack_base; | |
397 | arg_size = i << PAGE_SHIFT; | |
398 | ||
399 | /* zero pages that were copied above */ | |
400 | while (i < MAX_ARG_PAGES) | |
401 | bprm->page[i++] = NULL; | |
402 | #else | |
403 | stack_base = arch_align_stack(stack_top - MAX_ARG_PAGES*PAGE_SIZE); | |
404 | stack_base = PAGE_ALIGN(stack_base); | |
405 | bprm->p += stack_base; | |
406 | mm->arg_start = bprm->p; | |
407 | arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start); | |
408 | #endif | |
409 | ||
410 | arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE; | |
411 | ||
412 | if (bprm->loader) | |
413 | bprm->loader += stack_base; | |
414 | bprm->exec += stack_base; | |
415 | ||
416 | mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); | |
417 | if (!mpnt) | |
418 | return -ENOMEM; | |
419 | ||
420 | if (security_vm_enough_memory(arg_size >> PAGE_SHIFT)) { | |
421 | kmem_cache_free(vm_area_cachep, mpnt); | |
422 | return -ENOMEM; | |
423 | } | |
424 | ||
425 | memset(mpnt, 0, sizeof(*mpnt)); | |
426 | ||
427 | down_write(&mm->mmap_sem); | |
428 | { | |
429 | mpnt->vm_mm = mm; | |
430 | #ifdef CONFIG_STACK_GROWSUP | |
431 | mpnt->vm_start = stack_base; | |
432 | mpnt->vm_end = stack_base + arg_size; | |
433 | #else | |
434 | mpnt->vm_end = stack_top; | |
435 | mpnt->vm_start = mpnt->vm_end - arg_size; | |
436 | #endif | |
437 | /* Adjust stack execute permissions; explicitly enable | |
438 | * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X | |
439 | * and leave alone (arch default) otherwise. */ | |
440 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
441 | mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC; | |
442 | else if (executable_stack == EXSTACK_DISABLE_X) | |
443 | mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC; | |
444 | else | |
445 | mpnt->vm_flags = VM_STACK_FLAGS; | |
446 | mpnt->vm_flags |= mm->def_flags; | |
447 | mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7]; | |
448 | if ((ret = insert_vm_struct(mm, mpnt))) { | |
449 | up_write(&mm->mmap_sem); | |
450 | kmem_cache_free(vm_area_cachep, mpnt); | |
451 | return ret; | |
452 | } | |
453 | mm->stack_vm = mm->total_vm = vma_pages(mpnt); | |
454 | } | |
455 | ||
456 | for (i = 0 ; i < MAX_ARG_PAGES ; i++) { | |
457 | struct page *page = bprm->page[i]; | |
458 | if (page) { | |
459 | bprm->page[i] = NULL; | |
460 | install_arg_page(mpnt, page, stack_base); | |
461 | } | |
462 | stack_base += PAGE_SIZE; | |
463 | } | |
464 | up_write(&mm->mmap_sem); | |
465 | ||
466 | return 0; | |
467 | } | |
468 | ||
469 | EXPORT_SYMBOL(setup_arg_pages); | |
470 | ||
471 | #define free_arg_pages(bprm) do { } while (0) | |
472 | ||
473 | #else | |
474 | ||
475 | static inline void free_arg_pages(struct linux_binprm *bprm) | |
476 | { | |
477 | int i; | |
478 | ||
479 | for (i = 0; i < MAX_ARG_PAGES; i++) { | |
480 | if (bprm->page[i]) | |
481 | __free_page(bprm->page[i]); | |
482 | bprm->page[i] = NULL; | |
483 | } | |
484 | } | |
485 | ||
486 | #endif /* CONFIG_MMU */ | |
487 | ||
488 | struct file *open_exec(const char *name) | |
489 | { | |
490 | struct nameidata nd; | |
491 | int err; | |
492 | struct file *file; | |
493 | ||
494 | nd.intent.open.flags = FMODE_READ; | |
495 | err = path_lookup(name, LOOKUP_FOLLOW|LOOKUP_OPEN, &nd); | |
496 | file = ERR_PTR(err); | |
497 | ||
498 | if (!err) { | |
499 | struct inode *inode = nd.dentry->d_inode; | |
500 | file = ERR_PTR(-EACCES); | |
501 | if (!(nd.mnt->mnt_flags & MNT_NOEXEC) && | |
502 | S_ISREG(inode->i_mode)) { | |
503 | int err = permission(inode, MAY_EXEC, &nd); | |
504 | if (!err && !(inode->i_mode & 0111)) | |
505 | err = -EACCES; | |
506 | file = ERR_PTR(err); | |
507 | if (!err) { | |
508 | file = dentry_open(nd.dentry, nd.mnt, O_RDONLY); | |
509 | if (!IS_ERR(file)) { | |
510 | err = deny_write_access(file); | |
511 | if (err) { | |
512 | fput(file); | |
513 | file = ERR_PTR(err); | |
514 | } | |
515 | } | |
516 | out: | |
517 | return file; | |
518 | } | |
519 | } | |
520 | path_release(&nd); | |
521 | } | |
522 | goto out; | |
523 | } | |
524 | ||
525 | EXPORT_SYMBOL(open_exec); | |
526 | ||
527 | int kernel_read(struct file *file, unsigned long offset, | |
528 | char *addr, unsigned long count) | |
529 | { | |
530 | mm_segment_t old_fs; | |
531 | loff_t pos = offset; | |
532 | int result; | |
533 | ||
534 | old_fs = get_fs(); | |
535 | set_fs(get_ds()); | |
536 | /* The cast to a user pointer is valid due to the set_fs() */ | |
537 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
538 | set_fs(old_fs); | |
539 | return result; | |
540 | } | |
541 | ||
542 | EXPORT_SYMBOL(kernel_read); | |
543 | ||
544 | static int exec_mmap(struct mm_struct *mm) | |
545 | { | |
546 | struct task_struct *tsk; | |
547 | struct mm_struct * old_mm, *active_mm; | |
548 | ||
549 | /* Notify parent that we're no longer interested in the old VM */ | |
550 | tsk = current; | |
551 | old_mm = current->mm; | |
552 | mm_release(tsk, old_mm); | |
553 | ||
554 | if (old_mm) { | |
555 | /* | |
556 | * Make sure that if there is a core dump in progress | |
557 | * for the old mm, we get out and die instead of going | |
558 | * through with the exec. We must hold mmap_sem around | |
559 | * checking core_waiters and changing tsk->mm. The | |
560 | * core-inducing thread will increment core_waiters for | |
561 | * each thread whose ->mm == old_mm. | |
562 | */ | |
563 | down_read(&old_mm->mmap_sem); | |
564 | if (unlikely(old_mm->core_waiters)) { | |
565 | up_read(&old_mm->mmap_sem); | |
566 | return -EINTR; | |
567 | } | |
568 | } | |
569 | task_lock(tsk); | |
570 | active_mm = tsk->active_mm; | |
571 | tsk->mm = mm; | |
572 | tsk->active_mm = mm; | |
573 | activate_mm(active_mm, mm); | |
574 | task_unlock(tsk); | |
575 | arch_pick_mmap_layout(mm); | |
576 | if (old_mm) { | |
577 | up_read(&old_mm->mmap_sem); | |
578 | if (active_mm != old_mm) BUG(); | |
579 | mmput(old_mm); | |
580 | return 0; | |
581 | } | |
582 | mmdrop(active_mm); | |
583 | return 0; | |
584 | } | |
585 | ||
586 | /* | |
587 | * This function makes sure the current process has its own signal table, | |
588 | * so that flush_signal_handlers can later reset the handlers without | |
589 | * disturbing other processes. (Other processes might share the signal | |
590 | * table via the CLONE_SIGHAND option to clone().) | |
591 | */ | |
592 | static inline int de_thread(struct task_struct *tsk) | |
593 | { | |
594 | struct signal_struct *sig = tsk->signal; | |
595 | struct sighand_struct *newsighand, *oldsighand = tsk->sighand; | |
596 | spinlock_t *lock = &oldsighand->siglock; | |
597 | int count; | |
598 | ||
599 | /* | |
600 | * If we don't share sighandlers, then we aren't sharing anything | |
601 | * and we can just re-use it all. | |
602 | */ | |
603 | if (atomic_read(&oldsighand->count) <= 1) { | |
604 | BUG_ON(atomic_read(&sig->count) != 1); | |
605 | exit_itimers(sig); | |
606 | return 0; | |
607 | } | |
608 | ||
609 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); | |
610 | if (!newsighand) | |
611 | return -ENOMEM; | |
612 | ||
613 | if (thread_group_empty(current)) | |
614 | goto no_thread_group; | |
615 | ||
616 | /* | |
617 | * Kill all other threads in the thread group. | |
618 | * We must hold tasklist_lock to call zap_other_threads. | |
619 | */ | |
620 | read_lock(&tasklist_lock); | |
621 | spin_lock_irq(lock); | |
622 | if (sig->flags & SIGNAL_GROUP_EXIT) { | |
623 | /* | |
624 | * Another group action in progress, just | |
625 | * return so that the signal is processed. | |
626 | */ | |
627 | spin_unlock_irq(lock); | |
628 | read_unlock(&tasklist_lock); | |
629 | kmem_cache_free(sighand_cachep, newsighand); | |
630 | return -EAGAIN; | |
631 | } | |
632 | zap_other_threads(current); | |
633 | read_unlock(&tasklist_lock); | |
634 | ||
635 | /* | |
636 | * Account for the thread group leader hanging around: | |
637 | */ | |
638 | count = 2; | |
639 | if (thread_group_leader(current)) | |
640 | count = 1; | |
641 | while (atomic_read(&sig->count) > count) { | |
642 | sig->group_exit_task = current; | |
643 | sig->notify_count = count; | |
644 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
645 | spin_unlock_irq(lock); | |
646 | schedule(); | |
647 | spin_lock_irq(lock); | |
648 | } | |
649 | sig->group_exit_task = NULL; | |
650 | sig->notify_count = 0; | |
651 | spin_unlock_irq(lock); | |
652 | ||
653 | /* | |
654 | * At this point all other threads have exited, all we have to | |
655 | * do is to wait for the thread group leader to become inactive, | |
656 | * and to assume its PID: | |
657 | */ | |
658 | if (!thread_group_leader(current)) { | |
659 | struct task_struct *leader = current->group_leader, *parent; | |
660 | struct dentry *proc_dentry1, *proc_dentry2; | |
661 | unsigned long exit_state, ptrace; | |
662 | ||
663 | /* | |
664 | * Wait for the thread group leader to be a zombie. | |
665 | * It should already be zombie at this point, most | |
666 | * of the time. | |
667 | */ | |
668 | while (leader->exit_state != EXIT_ZOMBIE) | |
669 | yield(); | |
670 | ||
671 | spin_lock(&leader->proc_lock); | |
672 | spin_lock(¤t->proc_lock); | |
673 | proc_dentry1 = proc_pid_unhash(current); | |
674 | proc_dentry2 = proc_pid_unhash(leader); | |
675 | write_lock_irq(&tasklist_lock); | |
676 | ||
677 | if (leader->tgid != current->tgid) | |
678 | BUG(); | |
679 | if (current->pid == current->tgid) | |
680 | BUG(); | |
681 | /* | |
682 | * An exec() starts a new thread group with the | |
683 | * TGID of the previous thread group. Rehash the | |
684 | * two threads with a switched PID, and release | |
685 | * the former thread group leader: | |
686 | */ | |
687 | ptrace = leader->ptrace; | |
688 | parent = leader->parent; | |
689 | if (unlikely(ptrace) && unlikely(parent == current)) { | |
690 | /* | |
691 | * Joker was ptracing his own group leader, | |
692 | * and now he wants to be his own parent! | |
693 | * We can't have that. | |
694 | */ | |
695 | ptrace = 0; | |
696 | } | |
697 | ||
698 | ptrace_unlink(current); | |
699 | ptrace_unlink(leader); | |
700 | remove_parent(current); | |
701 | remove_parent(leader); | |
702 | ||
703 | switch_exec_pids(leader, current); | |
704 | ||
705 | current->parent = current->real_parent = leader->real_parent; | |
706 | leader->parent = leader->real_parent = child_reaper; | |
707 | current->group_leader = current; | |
708 | leader->group_leader = leader; | |
709 | ||
710 | add_parent(current, current->parent); | |
711 | add_parent(leader, leader->parent); | |
712 | if (ptrace) { | |
713 | current->ptrace = ptrace; | |
714 | __ptrace_link(current, parent); | |
715 | } | |
716 | ||
717 | list_del(¤t->tasks); | |
718 | list_add_tail(¤t->tasks, &init_task.tasks); | |
719 | current->exit_signal = SIGCHLD; | |
720 | exit_state = leader->exit_state; | |
721 | ||
722 | write_unlock_irq(&tasklist_lock); | |
723 | spin_unlock(&leader->proc_lock); | |
724 | spin_unlock(¤t->proc_lock); | |
725 | proc_pid_flush(proc_dentry1); | |
726 | proc_pid_flush(proc_dentry2); | |
727 | ||
728 | if (exit_state != EXIT_ZOMBIE) | |
729 | BUG(); | |
730 | release_task(leader); | |
731 | } | |
732 | ||
733 | /* | |
734 | * Now there are really no other threads at all, | |
735 | * so it's safe to stop telling them to kill themselves. | |
736 | */ | |
737 | sig->flags = 0; | |
738 | ||
739 | no_thread_group: | |
740 | BUG_ON(atomic_read(&sig->count) != 1); | |
741 | exit_itimers(sig); | |
742 | ||
743 | if (atomic_read(&oldsighand->count) == 1) { | |
744 | /* | |
745 | * Now that we nuked the rest of the thread group, | |
746 | * it turns out we are not sharing sighand any more either. | |
747 | * So we can just keep it. | |
748 | */ | |
749 | kmem_cache_free(sighand_cachep, newsighand); | |
750 | } else { | |
751 | /* | |
752 | * Move our state over to newsighand and switch it in. | |
753 | */ | |
754 | spin_lock_init(&newsighand->siglock); | |
755 | atomic_set(&newsighand->count, 1); | |
756 | memcpy(newsighand->action, oldsighand->action, | |
757 | sizeof(newsighand->action)); | |
758 | ||
759 | write_lock_irq(&tasklist_lock); | |
760 | spin_lock(&oldsighand->siglock); | |
761 | spin_lock(&newsighand->siglock); | |
762 | ||
763 | current->sighand = newsighand; | |
764 | recalc_sigpending(); | |
765 | ||
766 | spin_unlock(&newsighand->siglock); | |
767 | spin_unlock(&oldsighand->siglock); | |
768 | write_unlock_irq(&tasklist_lock); | |
769 | ||
770 | if (atomic_dec_and_test(&oldsighand->count)) | |
771 | kmem_cache_free(sighand_cachep, oldsighand); | |
772 | } | |
773 | ||
774 | if (!thread_group_empty(current)) | |
775 | BUG(); | |
776 | if (!thread_group_leader(current)) | |
777 | BUG(); | |
778 | return 0; | |
779 | } | |
780 | ||
781 | /* | |
782 | * These functions flushes out all traces of the currently running executable | |
783 | * so that a new one can be started | |
784 | */ | |
785 | ||
786 | static inline void flush_old_files(struct files_struct * files) | |
787 | { | |
788 | long j = -1; | |
789 | ||
790 | spin_lock(&files->file_lock); | |
791 | for (;;) { | |
792 | unsigned long set, i; | |
793 | ||
794 | j++; | |
795 | i = j * __NFDBITS; | |
796 | if (i >= files->max_fds || i >= files->max_fdset) | |
797 | break; | |
798 | set = files->close_on_exec->fds_bits[j]; | |
799 | if (!set) | |
800 | continue; | |
801 | files->close_on_exec->fds_bits[j] = 0; | |
802 | spin_unlock(&files->file_lock); | |
803 | for ( ; set ; i++,set >>= 1) { | |
804 | if (set & 1) { | |
805 | sys_close(i); | |
806 | } | |
807 | } | |
808 | spin_lock(&files->file_lock); | |
809 | ||
810 | } | |
811 | spin_unlock(&files->file_lock); | |
812 | } | |
813 | ||
814 | void get_task_comm(char *buf, struct task_struct *tsk) | |
815 | { | |
816 | /* buf must be at least sizeof(tsk->comm) in size */ | |
817 | task_lock(tsk); | |
818 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
819 | task_unlock(tsk); | |
820 | } | |
821 | ||
822 | void set_task_comm(struct task_struct *tsk, char *buf) | |
823 | { | |
824 | task_lock(tsk); | |
825 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); | |
826 | task_unlock(tsk); | |
827 | } | |
828 | ||
829 | int flush_old_exec(struct linux_binprm * bprm) | |
830 | { | |
831 | char * name; | |
832 | int i, ch, retval; | |
833 | struct files_struct *files; | |
834 | char tcomm[sizeof(current->comm)]; | |
835 | ||
836 | /* | |
837 | * Make sure we have a private signal table and that | |
838 | * we are unassociated from the previous thread group. | |
839 | */ | |
840 | retval = de_thread(current); | |
841 | if (retval) | |
842 | goto out; | |
843 | ||
844 | /* | |
845 | * Make sure we have private file handles. Ask the | |
846 | * fork helper to do the work for us and the exit | |
847 | * helper to do the cleanup of the old one. | |
848 | */ | |
849 | files = current->files; /* refcounted so safe to hold */ | |
850 | retval = unshare_files(); | |
851 | if (retval) | |
852 | goto out; | |
853 | /* | |
854 | * Release all of the old mmap stuff | |
855 | */ | |
856 | retval = exec_mmap(bprm->mm); | |
857 | if (retval) | |
858 | goto mmap_failed; | |
859 | ||
860 | bprm->mm = NULL; /* We're using it now */ | |
861 | ||
862 | /* This is the point of no return */ | |
863 | steal_locks(files); | |
864 | put_files_struct(files); | |
865 | ||
866 | current->sas_ss_sp = current->sas_ss_size = 0; | |
867 | ||
868 | if (current->euid == current->uid && current->egid == current->gid) | |
869 | current->mm->dumpable = 1; | |
870 | name = bprm->filename; | |
871 | for (i=0; (ch = *(name++)) != '\0';) { | |
872 | if (ch == '/') | |
873 | i = 0; | |
874 | else | |
875 | if (i < (sizeof(tcomm) - 1)) | |
876 | tcomm[i++] = ch; | |
877 | } | |
878 | tcomm[i] = '\0'; | |
879 | set_task_comm(current, tcomm); | |
880 | ||
881 | current->flags &= ~PF_RANDOMIZE; | |
882 | flush_thread(); | |
883 | ||
884 | if (bprm->e_uid != current->euid || bprm->e_gid != current->egid || | |
885 | permission(bprm->file->f_dentry->d_inode,MAY_READ, NULL) || | |
886 | (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { | |
887 | suid_keys(current); | |
888 | current->mm->dumpable = 0; | |
889 | } | |
890 | ||
891 | /* An exec changes our domain. We are no longer part of the thread | |
892 | group */ | |
893 | ||
894 | current->self_exec_id++; | |
895 | ||
896 | flush_signal_handlers(current, 0); | |
897 | flush_old_files(current->files); | |
898 | ||
899 | return 0; | |
900 | ||
901 | mmap_failed: | |
902 | put_files_struct(current->files); | |
903 | current->files = files; | |
904 | out: | |
905 | return retval; | |
906 | } | |
907 | ||
908 | EXPORT_SYMBOL(flush_old_exec); | |
909 | ||
910 | /* | |
911 | * Fill the binprm structure from the inode. | |
912 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
913 | */ | |
914 | int prepare_binprm(struct linux_binprm *bprm) | |
915 | { | |
916 | int mode; | |
917 | struct inode * inode = bprm->file->f_dentry->d_inode; | |
918 | int retval; | |
919 | ||
920 | mode = inode->i_mode; | |
921 | /* | |
922 | * Check execute perms again - if the caller has CAP_DAC_OVERRIDE, | |
923 | * generic_permission lets a non-executable through | |
924 | */ | |
925 | if (!(mode & 0111)) /* with at least _one_ execute bit set */ | |
926 | return -EACCES; | |
927 | if (bprm->file->f_op == NULL) | |
928 | return -EACCES; | |
929 | ||
930 | bprm->e_uid = current->euid; | |
931 | bprm->e_gid = current->egid; | |
932 | ||
933 | if(!(bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)) { | |
934 | /* Set-uid? */ | |
935 | if (mode & S_ISUID) { | |
936 | current->personality &= ~PER_CLEAR_ON_SETID; | |
937 | bprm->e_uid = inode->i_uid; | |
938 | } | |
939 | ||
940 | /* Set-gid? */ | |
941 | /* | |
942 | * If setgid is set but no group execute bit then this | |
943 | * is a candidate for mandatory locking, not a setgid | |
944 | * executable. | |
945 | */ | |
946 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
947 | current->personality &= ~PER_CLEAR_ON_SETID; | |
948 | bprm->e_gid = inode->i_gid; | |
949 | } | |
950 | } | |
951 | ||
952 | /* fill in binprm security blob */ | |
953 | retval = security_bprm_set(bprm); | |
954 | if (retval) | |
955 | return retval; | |
956 | ||
957 | memset(bprm->buf,0,BINPRM_BUF_SIZE); | |
958 | return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE); | |
959 | } | |
960 | ||
961 | EXPORT_SYMBOL(prepare_binprm); | |
962 | ||
963 | static inline int unsafe_exec(struct task_struct *p) | |
964 | { | |
965 | int unsafe = 0; | |
966 | if (p->ptrace & PT_PTRACED) { | |
967 | if (p->ptrace & PT_PTRACE_CAP) | |
968 | unsafe |= LSM_UNSAFE_PTRACE_CAP; | |
969 | else | |
970 | unsafe |= LSM_UNSAFE_PTRACE; | |
971 | } | |
972 | if (atomic_read(&p->fs->count) > 1 || | |
973 | atomic_read(&p->files->count) > 1 || | |
974 | atomic_read(&p->sighand->count) > 1) | |
975 | unsafe |= LSM_UNSAFE_SHARE; | |
976 | ||
977 | return unsafe; | |
978 | } | |
979 | ||
980 | void compute_creds(struct linux_binprm *bprm) | |
981 | { | |
982 | int unsafe; | |
983 | ||
984 | if (bprm->e_uid != current->uid) | |
985 | suid_keys(current); | |
986 | exec_keys(current); | |
987 | ||
988 | task_lock(current); | |
989 | unsafe = unsafe_exec(current); | |
990 | security_bprm_apply_creds(bprm, unsafe); | |
991 | task_unlock(current); | |
992 | security_bprm_post_apply_creds(bprm); | |
993 | } | |
994 | ||
995 | EXPORT_SYMBOL(compute_creds); | |
996 | ||
997 | void remove_arg_zero(struct linux_binprm *bprm) | |
998 | { | |
999 | if (bprm->argc) { | |
1000 | unsigned long offset; | |
1001 | char * kaddr; | |
1002 | struct page *page; | |
1003 | ||
1004 | offset = bprm->p % PAGE_SIZE; | |
1005 | goto inside; | |
1006 | ||
1007 | while (bprm->p++, *(kaddr+offset++)) { | |
1008 | if (offset != PAGE_SIZE) | |
1009 | continue; | |
1010 | offset = 0; | |
1011 | kunmap_atomic(kaddr, KM_USER0); | |
1012 | inside: | |
1013 | page = bprm->page[bprm->p/PAGE_SIZE]; | |
1014 | kaddr = kmap_atomic(page, KM_USER0); | |
1015 | } | |
1016 | kunmap_atomic(kaddr, KM_USER0); | |
1017 | bprm->argc--; | |
1018 | } | |
1019 | } | |
1020 | ||
1021 | EXPORT_SYMBOL(remove_arg_zero); | |
1022 | ||
1023 | /* | |
1024 | * cycle the list of binary formats handler, until one recognizes the image | |
1025 | */ | |
1026 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1027 | { | |
1028 | int try,retval; | |
1029 | struct linux_binfmt *fmt; | |
1030 | #ifdef __alpha__ | |
1031 | /* handle /sbin/loader.. */ | |
1032 | { | |
1033 | struct exec * eh = (struct exec *) bprm->buf; | |
1034 | ||
1035 | if (!bprm->loader && eh->fh.f_magic == 0x183 && | |
1036 | (eh->fh.f_flags & 0x3000) == 0x3000) | |
1037 | { | |
1038 | struct file * file; | |
1039 | unsigned long loader; | |
1040 | ||
1041 | allow_write_access(bprm->file); | |
1042 | fput(bprm->file); | |
1043 | bprm->file = NULL; | |
1044 | ||
1045 | loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); | |
1046 | ||
1047 | file = open_exec("/sbin/loader"); | |
1048 | retval = PTR_ERR(file); | |
1049 | if (IS_ERR(file)) | |
1050 | return retval; | |
1051 | ||
1052 | /* Remember if the application is TASO. */ | |
1053 | bprm->sh_bang = eh->ah.entry < 0x100000000UL; | |
1054 | ||
1055 | bprm->file = file; | |
1056 | bprm->loader = loader; | |
1057 | retval = prepare_binprm(bprm); | |
1058 | if (retval<0) | |
1059 | return retval; | |
1060 | /* should call search_binary_handler recursively here, | |
1061 | but it does not matter */ | |
1062 | } | |
1063 | } | |
1064 | #endif | |
1065 | retval = security_bprm_check(bprm); | |
1066 | if (retval) | |
1067 | return retval; | |
1068 | ||
1069 | /* kernel module loader fixup */ | |
1070 | /* so we don't try to load run modprobe in kernel space. */ | |
1071 | set_fs(USER_DS); | |
1072 | retval = -ENOENT; | |
1073 | for (try=0; try<2; try++) { | |
1074 | read_lock(&binfmt_lock); | |
1075 | for (fmt = formats ; fmt ; fmt = fmt->next) { | |
1076 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; | |
1077 | if (!fn) | |
1078 | continue; | |
1079 | if (!try_module_get(fmt->module)) | |
1080 | continue; | |
1081 | read_unlock(&binfmt_lock); | |
1082 | retval = fn(bprm, regs); | |
1083 | if (retval >= 0) { | |
1084 | put_binfmt(fmt); | |
1085 | allow_write_access(bprm->file); | |
1086 | if (bprm->file) | |
1087 | fput(bprm->file); | |
1088 | bprm->file = NULL; | |
1089 | current->did_exec = 1; | |
1090 | return retval; | |
1091 | } | |
1092 | read_lock(&binfmt_lock); | |
1093 | put_binfmt(fmt); | |
1094 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1095 | break; | |
1096 | if (!bprm->file) { | |
1097 | read_unlock(&binfmt_lock); | |
1098 | return retval; | |
1099 | } | |
1100 | } | |
1101 | read_unlock(&binfmt_lock); | |
1102 | if (retval != -ENOEXEC || bprm->mm == NULL) { | |
1103 | break; | |
1104 | #ifdef CONFIG_KMOD | |
1105 | }else{ | |
1106 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) | |
1107 | if (printable(bprm->buf[0]) && | |
1108 | printable(bprm->buf[1]) && | |
1109 | printable(bprm->buf[2]) && | |
1110 | printable(bprm->buf[3])) | |
1111 | break; /* -ENOEXEC */ | |
1112 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); | |
1113 | #endif | |
1114 | } | |
1115 | } | |
1116 | return retval; | |
1117 | } | |
1118 | ||
1119 | EXPORT_SYMBOL(search_binary_handler); | |
1120 | ||
1121 | /* | |
1122 | * sys_execve() executes a new program. | |
1123 | */ | |
1124 | int do_execve(char * filename, | |
1125 | char __user *__user *argv, | |
1126 | char __user *__user *envp, | |
1127 | struct pt_regs * regs) | |
1128 | { | |
1129 | struct linux_binprm *bprm; | |
1130 | struct file *file; | |
1131 | int retval; | |
1132 | int i; | |
1133 | ||
1134 | retval = -ENOMEM; | |
1135 | bprm = kmalloc(sizeof(*bprm), GFP_KERNEL); | |
1136 | if (!bprm) | |
1137 | goto out_ret; | |
1138 | memset(bprm, 0, sizeof(*bprm)); | |
1139 | ||
1140 | file = open_exec(filename); | |
1141 | retval = PTR_ERR(file); | |
1142 | if (IS_ERR(file)) | |
1143 | goto out_kfree; | |
1144 | ||
1145 | sched_exec(); | |
1146 | ||
1147 | bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); | |
1148 | ||
1149 | bprm->file = file; | |
1150 | bprm->filename = filename; | |
1151 | bprm->interp = filename; | |
1152 | bprm->mm = mm_alloc(); | |
1153 | retval = -ENOMEM; | |
1154 | if (!bprm->mm) | |
1155 | goto out_file; | |
1156 | ||
1157 | retval = init_new_context(current, bprm->mm); | |
1158 | if (retval < 0) | |
1159 | goto out_mm; | |
1160 | ||
1161 | bprm->argc = count(argv, bprm->p / sizeof(void *)); | |
1162 | if ((retval = bprm->argc) < 0) | |
1163 | goto out_mm; | |
1164 | ||
1165 | bprm->envc = count(envp, bprm->p / sizeof(void *)); | |
1166 | if ((retval = bprm->envc) < 0) | |
1167 | goto out_mm; | |
1168 | ||
1169 | retval = security_bprm_alloc(bprm); | |
1170 | if (retval) | |
1171 | goto out; | |
1172 | ||
1173 | retval = prepare_binprm(bprm); | |
1174 | if (retval < 0) | |
1175 | goto out; | |
1176 | ||
1177 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1178 | if (retval < 0) | |
1179 | goto out; | |
1180 | ||
1181 | bprm->exec = bprm->p; | |
1182 | retval = copy_strings(bprm->envc, envp, bprm); | |
1183 | if (retval < 0) | |
1184 | goto out; | |
1185 | ||
1186 | retval = copy_strings(bprm->argc, argv, bprm); | |
1187 | if (retval < 0) | |
1188 | goto out; | |
1189 | ||
1190 | retval = search_binary_handler(bprm,regs); | |
1191 | if (retval >= 0) { | |
1192 | free_arg_pages(bprm); | |
1193 | ||
1194 | /* execve success */ | |
1195 | security_bprm_free(bprm); | |
1196 | acct_update_integrals(current); | |
1197 | update_mem_hiwater(current); | |
1198 | kfree(bprm); | |
1199 | return retval; | |
1200 | } | |
1201 | ||
1202 | out: | |
1203 | /* Something went wrong, return the inode and free the argument pages*/ | |
1204 | for (i = 0 ; i < MAX_ARG_PAGES ; i++) { | |
1205 | struct page * page = bprm->page[i]; | |
1206 | if (page) | |
1207 | __free_page(page); | |
1208 | } | |
1209 | ||
1210 | if (bprm->security) | |
1211 | security_bprm_free(bprm); | |
1212 | ||
1213 | out_mm: | |
1214 | if (bprm->mm) | |
1215 | mmdrop(bprm->mm); | |
1216 | ||
1217 | out_file: | |
1218 | if (bprm->file) { | |
1219 | allow_write_access(bprm->file); | |
1220 | fput(bprm->file); | |
1221 | } | |
1222 | ||
1223 | out_kfree: | |
1224 | kfree(bprm); | |
1225 | ||
1226 | out_ret: | |
1227 | return retval; | |
1228 | } | |
1229 | ||
1230 | int set_binfmt(struct linux_binfmt *new) | |
1231 | { | |
1232 | struct linux_binfmt *old = current->binfmt; | |
1233 | ||
1234 | if (new) { | |
1235 | if (!try_module_get(new->module)) | |
1236 | return -1; | |
1237 | } | |
1238 | current->binfmt = new; | |
1239 | if (old) | |
1240 | module_put(old->module); | |
1241 | return 0; | |
1242 | } | |
1243 | ||
1244 | EXPORT_SYMBOL(set_binfmt); | |
1245 | ||
1246 | #define CORENAME_MAX_SIZE 64 | |
1247 | ||
1248 | /* format_corename will inspect the pattern parameter, and output a | |
1249 | * name into corename, which must have space for at least | |
1250 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
1251 | */ | |
1252 | static void format_corename(char *corename, const char *pattern, long signr) | |
1253 | { | |
1254 | const char *pat_ptr = pattern; | |
1255 | char *out_ptr = corename; | |
1256 | char *const out_end = corename + CORENAME_MAX_SIZE; | |
1257 | int rc; | |
1258 | int pid_in_pattern = 0; | |
1259 | ||
1260 | /* Repeat as long as we have more pattern to process and more output | |
1261 | space */ | |
1262 | while (*pat_ptr) { | |
1263 | if (*pat_ptr != '%') { | |
1264 | if (out_ptr == out_end) | |
1265 | goto out; | |
1266 | *out_ptr++ = *pat_ptr++; | |
1267 | } else { | |
1268 | switch (*++pat_ptr) { | |
1269 | case 0: | |
1270 | goto out; | |
1271 | /* Double percent, output one percent */ | |
1272 | case '%': | |
1273 | if (out_ptr == out_end) | |
1274 | goto out; | |
1275 | *out_ptr++ = '%'; | |
1276 | break; | |
1277 | /* pid */ | |
1278 | case 'p': | |
1279 | pid_in_pattern = 1; | |
1280 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1281 | "%d", current->tgid); | |
1282 | if (rc > out_end - out_ptr) | |
1283 | goto out; | |
1284 | out_ptr += rc; | |
1285 | break; | |
1286 | /* uid */ | |
1287 | case 'u': | |
1288 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1289 | "%d", current->uid); | |
1290 | if (rc > out_end - out_ptr) | |
1291 | goto out; | |
1292 | out_ptr += rc; | |
1293 | break; | |
1294 | /* gid */ | |
1295 | case 'g': | |
1296 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1297 | "%d", current->gid); | |
1298 | if (rc > out_end - out_ptr) | |
1299 | goto out; | |
1300 | out_ptr += rc; | |
1301 | break; | |
1302 | /* signal that caused the coredump */ | |
1303 | case 's': | |
1304 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1305 | "%ld", signr); | |
1306 | if (rc > out_end - out_ptr) | |
1307 | goto out; | |
1308 | out_ptr += rc; | |
1309 | break; | |
1310 | /* UNIX time of coredump */ | |
1311 | case 't': { | |
1312 | struct timeval tv; | |
1313 | do_gettimeofday(&tv); | |
1314 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1315 | "%lu", tv.tv_sec); | |
1316 | if (rc > out_end - out_ptr) | |
1317 | goto out; | |
1318 | out_ptr += rc; | |
1319 | break; | |
1320 | } | |
1321 | /* hostname */ | |
1322 | case 'h': | |
1323 | down_read(&uts_sem); | |
1324 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1325 | "%s", system_utsname.nodename); | |
1326 | up_read(&uts_sem); | |
1327 | if (rc > out_end - out_ptr) | |
1328 | goto out; | |
1329 | out_ptr += rc; | |
1330 | break; | |
1331 | /* executable */ | |
1332 | case 'e': | |
1333 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1334 | "%s", current->comm); | |
1335 | if (rc > out_end - out_ptr) | |
1336 | goto out; | |
1337 | out_ptr += rc; | |
1338 | break; | |
1339 | default: | |
1340 | break; | |
1341 | } | |
1342 | ++pat_ptr; | |
1343 | } | |
1344 | } | |
1345 | /* Backward compatibility with core_uses_pid: | |
1346 | * | |
1347 | * If core_pattern does not include a %p (as is the default) | |
1348 | * and core_uses_pid is set, then .%pid will be appended to | |
1349 | * the filename */ | |
1350 | if (!pid_in_pattern | |
1351 | && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) { | |
1352 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1353 | ".%d", current->tgid); | |
1354 | if (rc > out_end - out_ptr) | |
1355 | goto out; | |
1356 | out_ptr += rc; | |
1357 | } | |
1358 | out: | |
1359 | *out_ptr = 0; | |
1360 | } | |
1361 | ||
1362 | static void zap_threads (struct mm_struct *mm) | |
1363 | { | |
1364 | struct task_struct *g, *p; | |
1365 | struct task_struct *tsk = current; | |
1366 | struct completion *vfork_done = tsk->vfork_done; | |
1367 | int traced = 0; | |
1368 | ||
1369 | /* | |
1370 | * Make sure nobody is waiting for us to release the VM, | |
1371 | * otherwise we can deadlock when we wait on each other | |
1372 | */ | |
1373 | if (vfork_done) { | |
1374 | tsk->vfork_done = NULL; | |
1375 | complete(vfork_done); | |
1376 | } | |
1377 | ||
1378 | read_lock(&tasklist_lock); | |
1379 | do_each_thread(g,p) | |
1380 | if (mm == p->mm && p != tsk) { | |
1381 | force_sig_specific(SIGKILL, p); | |
1382 | mm->core_waiters++; | |
1383 | if (unlikely(p->ptrace) && | |
1384 | unlikely(p->parent->mm == mm)) | |
1385 | traced = 1; | |
1386 | } | |
1387 | while_each_thread(g,p); | |
1388 | ||
1389 | read_unlock(&tasklist_lock); | |
1390 | ||
1391 | if (unlikely(traced)) { | |
1392 | /* | |
1393 | * We are zapping a thread and the thread it ptraces. | |
1394 | * If the tracee went into a ptrace stop for exit tracing, | |
1395 | * we could deadlock since the tracer is waiting for this | |
1396 | * coredump to finish. Detach them so they can both die. | |
1397 | */ | |
1398 | write_lock_irq(&tasklist_lock); | |
1399 | do_each_thread(g,p) { | |
1400 | if (mm == p->mm && p != tsk && | |
1401 | p->ptrace && p->parent->mm == mm) { | |
1402 | __ptrace_unlink(p); | |
1403 | } | |
1404 | } while_each_thread(g,p); | |
1405 | write_unlock_irq(&tasklist_lock); | |
1406 | } | |
1407 | } | |
1408 | ||
1409 | static void coredump_wait(struct mm_struct *mm) | |
1410 | { | |
1411 | DECLARE_COMPLETION(startup_done); | |
1412 | ||
1413 | mm->core_waiters++; /* let other threads block */ | |
1414 | mm->core_startup_done = &startup_done; | |
1415 | ||
1416 | /* give other threads a chance to run: */ | |
1417 | yield(); | |
1418 | ||
1419 | zap_threads(mm); | |
1420 | if (--mm->core_waiters) { | |
1421 | up_write(&mm->mmap_sem); | |
1422 | wait_for_completion(&startup_done); | |
1423 | } else | |
1424 | up_write(&mm->mmap_sem); | |
1425 | BUG_ON(mm->core_waiters); | |
1426 | } | |
1427 | ||
1428 | int do_coredump(long signr, int exit_code, struct pt_regs * regs) | |
1429 | { | |
1430 | char corename[CORENAME_MAX_SIZE + 1]; | |
1431 | struct mm_struct *mm = current->mm; | |
1432 | struct linux_binfmt * binfmt; | |
1433 | struct inode * inode; | |
1434 | struct file * file; | |
1435 | int retval = 0; | |
1436 | ||
1437 | binfmt = current->binfmt; | |
1438 | if (!binfmt || !binfmt->core_dump) | |
1439 | goto fail; | |
1440 | down_write(&mm->mmap_sem); | |
1441 | if (!mm->dumpable) { | |
1442 | up_write(&mm->mmap_sem); | |
1443 | goto fail; | |
1444 | } | |
1445 | mm->dumpable = 0; | |
1446 | init_completion(&mm->core_done); | |
1447 | spin_lock_irq(¤t->sighand->siglock); | |
1448 | current->signal->flags = SIGNAL_GROUP_EXIT; | |
1449 | current->signal->group_exit_code = exit_code; | |
1450 | spin_unlock_irq(¤t->sighand->siglock); | |
1451 | coredump_wait(mm); | |
1452 | ||
1453 | /* | |
1454 | * Clear any false indication of pending signals that might | |
1455 | * be seen by the filesystem code called to write the core file. | |
1456 | */ | |
1457 | current->signal->group_stop_count = 0; | |
1458 | clear_thread_flag(TIF_SIGPENDING); | |
1459 | ||
1460 | if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump) | |
1461 | goto fail_unlock; | |
1462 | ||
1463 | /* | |
1464 | * lock_kernel() because format_corename() is controlled by sysctl, which | |
1465 | * uses lock_kernel() | |
1466 | */ | |
1467 | lock_kernel(); | |
1468 | format_corename(corename, core_pattern, signr); | |
1469 | unlock_kernel(); | |
1470 | file = filp_open(corename, O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE, 0600); | |
1471 | if (IS_ERR(file)) | |
1472 | goto fail_unlock; | |
1473 | inode = file->f_dentry->d_inode; | |
1474 | if (inode->i_nlink > 1) | |
1475 | goto close_fail; /* multiple links - don't dump */ | |
1476 | if (d_unhashed(file->f_dentry)) | |
1477 | goto close_fail; | |
1478 | ||
1479 | if (!S_ISREG(inode->i_mode)) | |
1480 | goto close_fail; | |
1481 | if (!file->f_op) | |
1482 | goto close_fail; | |
1483 | if (!file->f_op->write) | |
1484 | goto close_fail; | |
1485 | if (do_truncate(file->f_dentry, 0) != 0) | |
1486 | goto close_fail; | |
1487 | ||
1488 | retval = binfmt->core_dump(signr, regs, file); | |
1489 | ||
1490 | if (retval) | |
1491 | current->signal->group_exit_code |= 0x80; | |
1492 | close_fail: | |
1493 | filp_close(file, NULL); | |
1494 | fail_unlock: | |
1495 | complete_all(&mm->core_done); | |
1496 | fail: | |
1497 | return retval; | |
1498 | } |