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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 | ||
1da177e4 LT |
25 | #include <linux/slab.h> |
26 | #include <linux/file.h> | |
27 | #include <linux/mman.h> | |
28 | #include <linux/a.out.h> | |
29 | #include <linux/stat.h> | |
30 | #include <linux/fcntl.h> | |
31 | #include <linux/smp_lock.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/pagemap.h> | |
34 | #include <linux/highmem.h> | |
35 | #include <linux/spinlock.h> | |
36 | #include <linux/key.h> | |
37 | #include <linux/personality.h> | |
38 | #include <linux/binfmts.h> | |
39 | #include <linux/swap.h> | |
40 | #include <linux/utsname.h> | |
84d73786 | 41 | #include <linux/pid_namespace.h> |
1da177e4 LT |
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> | |
8f0ab514 | 50 | #include <linux/tsacct_kern.h> |
9f46080c | 51 | #include <linux/cn_proc.h> |
473ae30b | 52 | #include <linux/audit.h> |
fba2afaa | 53 | #include <linux/signalfd.h> |
1da177e4 LT |
54 | |
55 | #include <asm/uaccess.h> | |
56 | #include <asm/mmu_context.h> | |
57 | ||
58 | #ifdef CONFIG_KMOD | |
59 | #include <linux/kmod.h> | |
60 | #endif | |
61 | ||
62 | int core_uses_pid; | |
d025c9db | 63 | char core_pattern[128] = "core"; |
d6e71144 AC |
64 | int suid_dumpable = 0; |
65 | ||
66 | EXPORT_SYMBOL(suid_dumpable); | |
1da177e4 LT |
67 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
68 | ||
69 | static struct linux_binfmt *formats; | |
70 | static DEFINE_RWLOCK(binfmt_lock); | |
71 | ||
72 | int register_binfmt(struct linux_binfmt * fmt) | |
73 | { | |
74 | struct linux_binfmt ** tmp = &formats; | |
75 | ||
76 | if (!fmt) | |
77 | return -EINVAL; | |
78 | if (fmt->next) | |
79 | return -EBUSY; | |
80 | write_lock(&binfmt_lock); | |
81 | while (*tmp) { | |
82 | if (fmt == *tmp) { | |
83 | write_unlock(&binfmt_lock); | |
84 | return -EBUSY; | |
85 | } | |
86 | tmp = &(*tmp)->next; | |
87 | } | |
88 | fmt->next = formats; | |
89 | formats = fmt; | |
90 | write_unlock(&binfmt_lock); | |
91 | return 0; | |
92 | } | |
93 | ||
94 | EXPORT_SYMBOL(register_binfmt); | |
95 | ||
96 | int unregister_binfmt(struct linux_binfmt * fmt) | |
97 | { | |
98 | struct linux_binfmt ** tmp = &formats; | |
99 | ||
100 | write_lock(&binfmt_lock); | |
101 | while (*tmp) { | |
102 | if (fmt == *tmp) { | |
103 | *tmp = fmt->next; | |
98701d1b | 104 | fmt->next = NULL; |
1da177e4 LT |
105 | write_unlock(&binfmt_lock); |
106 | return 0; | |
107 | } | |
108 | tmp = &(*tmp)->next; | |
109 | } | |
110 | write_unlock(&binfmt_lock); | |
111 | return -EINVAL; | |
112 | } | |
113 | ||
114 | EXPORT_SYMBOL(unregister_binfmt); | |
115 | ||
116 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
117 | { | |
118 | module_put(fmt->module); | |
119 | } | |
120 | ||
121 | /* | |
122 | * Note that a shared library must be both readable and executable due to | |
123 | * security reasons. | |
124 | * | |
125 | * Also note that we take the address to load from from the file itself. | |
126 | */ | |
127 | asmlinkage long sys_uselib(const char __user * library) | |
128 | { | |
129 | struct file * file; | |
130 | struct nameidata nd; | |
131 | int error; | |
132 | ||
b500531e | 133 | error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); |
1da177e4 LT |
134 | if (error) |
135 | goto out; | |
136 | ||
137 | error = -EINVAL; | |
138 | if (!S_ISREG(nd.dentry->d_inode->i_mode)) | |
139 | goto exit; | |
140 | ||
e4543edd | 141 | error = vfs_permission(&nd, MAY_READ | MAY_EXEC); |
1da177e4 LT |
142 | if (error) |
143 | goto exit; | |
144 | ||
834f2a4a | 145 | file = nameidata_to_filp(&nd, O_RDONLY); |
1da177e4 LT |
146 | error = PTR_ERR(file); |
147 | if (IS_ERR(file)) | |
148 | goto out; | |
149 | ||
150 | error = -ENOEXEC; | |
151 | if(file->f_op) { | |
152 | struct linux_binfmt * fmt; | |
153 | ||
154 | read_lock(&binfmt_lock); | |
155 | for (fmt = formats ; fmt ; fmt = fmt->next) { | |
156 | if (!fmt->load_shlib) | |
157 | continue; | |
158 | if (!try_module_get(fmt->module)) | |
159 | continue; | |
160 | read_unlock(&binfmt_lock); | |
161 | error = fmt->load_shlib(file); | |
162 | read_lock(&binfmt_lock); | |
163 | put_binfmt(fmt); | |
164 | if (error != -ENOEXEC) | |
165 | break; | |
166 | } | |
167 | read_unlock(&binfmt_lock); | |
168 | } | |
169 | fput(file); | |
170 | out: | |
171 | return error; | |
172 | exit: | |
834f2a4a | 173 | release_open_intent(&nd); |
1da177e4 LT |
174 | path_release(&nd); |
175 | goto out; | |
176 | } | |
177 | ||
178 | /* | |
179 | * count() counts the number of strings in array ARGV. | |
180 | */ | |
181 | static int count(char __user * __user * argv, int max) | |
182 | { | |
183 | int i = 0; | |
184 | ||
185 | if (argv != NULL) { | |
186 | for (;;) { | |
187 | char __user * p; | |
188 | ||
189 | if (get_user(p, argv)) | |
190 | return -EFAULT; | |
191 | if (!p) | |
192 | break; | |
193 | argv++; | |
194 | if(++i > max) | |
195 | return -E2BIG; | |
196 | cond_resched(); | |
197 | } | |
198 | } | |
199 | return i; | |
200 | } | |
201 | ||
202 | /* | |
203 | * 'copy_strings()' copies argument/environment strings from user | |
204 | * memory to free pages in kernel mem. These are in a format ready | |
205 | * to be put directly into the top of new user memory. | |
206 | */ | |
75c96f85 AB |
207 | static int copy_strings(int argc, char __user * __user * argv, |
208 | struct linux_binprm *bprm) | |
1da177e4 LT |
209 | { |
210 | struct page *kmapped_page = NULL; | |
211 | char *kaddr = NULL; | |
212 | int ret; | |
213 | ||
214 | while (argc-- > 0) { | |
215 | char __user *str; | |
216 | int len; | |
217 | unsigned long pos; | |
218 | ||
219 | if (get_user(str, argv+argc) || | |
220 | !(len = strnlen_user(str, bprm->p))) { | |
221 | ret = -EFAULT; | |
222 | goto out; | |
223 | } | |
224 | ||
225 | if (bprm->p < len) { | |
226 | ret = -E2BIG; | |
227 | goto out; | |
228 | } | |
229 | ||
230 | bprm->p -= len; | |
231 | /* XXX: add architecture specific overflow check here. */ | |
232 | pos = bprm->p; | |
233 | ||
234 | while (len > 0) { | |
235 | int i, new, err; | |
236 | int offset, bytes_to_copy; | |
237 | struct page *page; | |
238 | ||
239 | offset = pos % PAGE_SIZE; | |
240 | i = pos/PAGE_SIZE; | |
241 | page = bprm->page[i]; | |
242 | new = 0; | |
243 | if (!page) { | |
244 | page = alloc_page(GFP_HIGHUSER); | |
245 | bprm->page[i] = page; | |
246 | if (!page) { | |
247 | ret = -ENOMEM; | |
248 | goto out; | |
249 | } | |
250 | new = 1; | |
251 | } | |
252 | ||
253 | if (page != kmapped_page) { | |
254 | if (kmapped_page) | |
255 | kunmap(kmapped_page); | |
256 | kmapped_page = page; | |
257 | kaddr = kmap(kmapped_page); | |
258 | } | |
259 | if (new && offset) | |
260 | memset(kaddr, 0, offset); | |
261 | bytes_to_copy = PAGE_SIZE - offset; | |
262 | if (bytes_to_copy > len) { | |
263 | bytes_to_copy = len; | |
264 | if (new) | |
265 | memset(kaddr+offset+len, 0, | |
266 | PAGE_SIZE-offset-len); | |
267 | } | |
268 | err = copy_from_user(kaddr+offset, str, bytes_to_copy); | |
269 | if (err) { | |
270 | ret = -EFAULT; | |
271 | goto out; | |
272 | } | |
273 | ||
274 | pos += bytes_to_copy; | |
275 | str += bytes_to_copy; | |
276 | len -= bytes_to_copy; | |
277 | } | |
278 | } | |
279 | ret = 0; | |
280 | out: | |
281 | if (kmapped_page) | |
282 | kunmap(kmapped_page); | |
283 | return ret; | |
284 | } | |
285 | ||
286 | /* | |
287 | * Like copy_strings, but get argv and its values from kernel memory. | |
288 | */ | |
289 | int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) | |
290 | { | |
291 | int r; | |
292 | mm_segment_t oldfs = get_fs(); | |
293 | set_fs(KERNEL_DS); | |
294 | r = copy_strings(argc, (char __user * __user *)argv, bprm); | |
295 | set_fs(oldfs); | |
296 | return r; | |
297 | } | |
298 | ||
299 | EXPORT_SYMBOL(copy_strings_kernel); | |
300 | ||
301 | #ifdef CONFIG_MMU | |
302 | /* | |
303 | * This routine is used to map in a page into an address space: needed by | |
304 | * execve() for the initial stack and environment pages. | |
305 | * | |
306 | * vma->vm_mm->mmap_sem is held for writing. | |
307 | */ | |
308 | void install_arg_page(struct vm_area_struct *vma, | |
309 | struct page *page, unsigned long address) | |
310 | { | |
311 | struct mm_struct *mm = vma->vm_mm; | |
1da177e4 | 312 | pte_t * pte; |
c74df32c | 313 | spinlock_t *ptl; |
1da177e4 LT |
314 | |
315 | if (unlikely(anon_vma_prepare(vma))) | |
c74df32c | 316 | goto out; |
1da177e4 LT |
317 | |
318 | flush_dcache_page(page); | |
c9cfcddf | 319 | pte = get_locked_pte(mm, address, &ptl); |
1da177e4 LT |
320 | if (!pte) |
321 | goto out; | |
322 | if (!pte_none(*pte)) { | |
c74df32c | 323 | pte_unmap_unlock(pte, ptl); |
1da177e4 LT |
324 | goto out; |
325 | } | |
4294621f | 326 | inc_mm_counter(mm, anon_rss); |
1da177e4 LT |
327 | lru_cache_add_active(page); |
328 | set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte( | |
329 | page, vma->vm_page_prot)))); | |
9617d95e | 330 | page_add_new_anon_rmap(page, vma, address); |
c74df32c | 331 | pte_unmap_unlock(pte, ptl); |
1da177e4 LT |
332 | |
333 | /* no need for flush_tlb */ | |
334 | return; | |
335 | out: | |
1da177e4 LT |
336 | __free_page(page); |
337 | force_sig(SIGKILL, current); | |
338 | } | |
339 | ||
340 | #define EXTRA_STACK_VM_PAGES 20 /* random */ | |
341 | ||
342 | int setup_arg_pages(struct linux_binprm *bprm, | |
343 | unsigned long stack_top, | |
344 | int executable_stack) | |
345 | { | |
346 | unsigned long stack_base; | |
347 | struct vm_area_struct *mpnt; | |
348 | struct mm_struct *mm = current->mm; | |
349 | int i, ret; | |
350 | long arg_size; | |
351 | ||
352 | #ifdef CONFIG_STACK_GROWSUP | |
353 | /* Move the argument and environment strings to the bottom of the | |
354 | * stack space. | |
355 | */ | |
356 | int offset, j; | |
357 | char *to, *from; | |
358 | ||
359 | /* Start by shifting all the pages down */ | |
360 | i = 0; | |
361 | for (j = 0; j < MAX_ARG_PAGES; j++) { | |
362 | struct page *page = bprm->page[j]; | |
363 | if (!page) | |
364 | continue; | |
365 | bprm->page[i++] = page; | |
366 | } | |
367 | ||
368 | /* Now move them within their pages */ | |
369 | offset = bprm->p % PAGE_SIZE; | |
370 | to = kmap(bprm->page[0]); | |
371 | for (j = 1; j < i; j++) { | |
372 | memmove(to, to + offset, PAGE_SIZE - offset); | |
373 | from = kmap(bprm->page[j]); | |
374 | memcpy(to + PAGE_SIZE - offset, from, offset); | |
375 | kunmap(bprm->page[j - 1]); | |
376 | to = from; | |
377 | } | |
378 | memmove(to, to + offset, PAGE_SIZE - offset); | |
379 | kunmap(bprm->page[j - 1]); | |
380 | ||
381 | /* Limit stack size to 1GB */ | |
382 | stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max; | |
383 | if (stack_base > (1 << 30)) | |
384 | stack_base = 1 << 30; | |
385 | stack_base = PAGE_ALIGN(stack_top - stack_base); | |
386 | ||
387 | /* Adjust bprm->p to point to the end of the strings. */ | |
388 | bprm->p = stack_base + PAGE_SIZE * i - offset; | |
389 | ||
390 | mm->arg_start = stack_base; | |
391 | arg_size = i << PAGE_SHIFT; | |
392 | ||
393 | /* zero pages that were copied above */ | |
394 | while (i < MAX_ARG_PAGES) | |
395 | bprm->page[i++] = NULL; | |
396 | #else | |
397 | stack_base = arch_align_stack(stack_top - MAX_ARG_PAGES*PAGE_SIZE); | |
398 | stack_base = PAGE_ALIGN(stack_base); | |
399 | bprm->p += stack_base; | |
400 | mm->arg_start = bprm->p; | |
401 | arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start); | |
402 | #endif | |
403 | ||
404 | arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE; | |
405 | ||
406 | if (bprm->loader) | |
407 | bprm->loader += stack_base; | |
408 | bprm->exec += stack_base; | |
409 | ||
c3762229 | 410 | mpnt = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
411 | if (!mpnt) |
412 | return -ENOMEM; | |
413 | ||
1da177e4 LT |
414 | down_write(&mm->mmap_sem); |
415 | { | |
416 | mpnt->vm_mm = mm; | |
417 | #ifdef CONFIG_STACK_GROWSUP | |
418 | mpnt->vm_start = stack_base; | |
419 | mpnt->vm_end = stack_base + arg_size; | |
420 | #else | |
421 | mpnt->vm_end = stack_top; | |
422 | mpnt->vm_start = mpnt->vm_end - arg_size; | |
423 | #endif | |
424 | /* Adjust stack execute permissions; explicitly enable | |
425 | * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X | |
426 | * and leave alone (arch default) otherwise. */ | |
427 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
428 | mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC; | |
429 | else if (executable_stack == EXSTACK_DISABLE_X) | |
430 | mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC; | |
431 | else | |
432 | mpnt->vm_flags = VM_STACK_FLAGS; | |
433 | mpnt->vm_flags |= mm->def_flags; | |
434 | mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7]; | |
435 | if ((ret = insert_vm_struct(mm, mpnt))) { | |
436 | up_write(&mm->mmap_sem); | |
437 | kmem_cache_free(vm_area_cachep, mpnt); | |
438 | return ret; | |
439 | } | |
440 | mm->stack_vm = mm->total_vm = vma_pages(mpnt); | |
441 | } | |
442 | ||
443 | for (i = 0 ; i < MAX_ARG_PAGES ; i++) { | |
444 | struct page *page = bprm->page[i]; | |
445 | if (page) { | |
446 | bprm->page[i] = NULL; | |
447 | install_arg_page(mpnt, page, stack_base); | |
448 | } | |
449 | stack_base += PAGE_SIZE; | |
450 | } | |
451 | up_write(&mm->mmap_sem); | |
452 | ||
453 | return 0; | |
454 | } | |
455 | ||
456 | EXPORT_SYMBOL(setup_arg_pages); | |
457 | ||
458 | #define free_arg_pages(bprm) do { } while (0) | |
459 | ||
460 | #else | |
461 | ||
462 | static inline void free_arg_pages(struct linux_binprm *bprm) | |
463 | { | |
464 | int i; | |
465 | ||
466 | for (i = 0; i < MAX_ARG_PAGES; i++) { | |
467 | if (bprm->page[i]) | |
468 | __free_page(bprm->page[i]); | |
469 | bprm->page[i] = NULL; | |
470 | } | |
471 | } | |
472 | ||
473 | #endif /* CONFIG_MMU */ | |
474 | ||
475 | struct file *open_exec(const char *name) | |
476 | { | |
477 | struct nameidata nd; | |
478 | int err; | |
479 | struct file *file; | |
480 | ||
b500531e | 481 | err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); |
1da177e4 LT |
482 | file = ERR_PTR(err); |
483 | ||
484 | if (!err) { | |
485 | struct inode *inode = nd.dentry->d_inode; | |
486 | file = ERR_PTR(-EACCES); | |
487 | if (!(nd.mnt->mnt_flags & MNT_NOEXEC) && | |
488 | S_ISREG(inode->i_mode)) { | |
e4543edd | 489 | int err = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
490 | file = ERR_PTR(err); |
491 | if (!err) { | |
834f2a4a | 492 | file = nameidata_to_filp(&nd, O_RDONLY); |
1da177e4 LT |
493 | if (!IS_ERR(file)) { |
494 | err = deny_write_access(file); | |
495 | if (err) { | |
496 | fput(file); | |
497 | file = ERR_PTR(err); | |
498 | } | |
499 | } | |
500 | out: | |
501 | return file; | |
502 | } | |
503 | } | |
834f2a4a | 504 | release_open_intent(&nd); |
1da177e4 LT |
505 | path_release(&nd); |
506 | } | |
507 | goto out; | |
508 | } | |
509 | ||
510 | EXPORT_SYMBOL(open_exec); | |
511 | ||
512 | int kernel_read(struct file *file, unsigned long offset, | |
513 | char *addr, unsigned long count) | |
514 | { | |
515 | mm_segment_t old_fs; | |
516 | loff_t pos = offset; | |
517 | int result; | |
518 | ||
519 | old_fs = get_fs(); | |
520 | set_fs(get_ds()); | |
521 | /* The cast to a user pointer is valid due to the set_fs() */ | |
522 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
523 | set_fs(old_fs); | |
524 | return result; | |
525 | } | |
526 | ||
527 | EXPORT_SYMBOL(kernel_read); | |
528 | ||
529 | static int exec_mmap(struct mm_struct *mm) | |
530 | { | |
531 | struct task_struct *tsk; | |
532 | struct mm_struct * old_mm, *active_mm; | |
533 | ||
534 | /* Notify parent that we're no longer interested in the old VM */ | |
535 | tsk = current; | |
536 | old_mm = current->mm; | |
537 | mm_release(tsk, old_mm); | |
538 | ||
539 | if (old_mm) { | |
540 | /* | |
541 | * Make sure that if there is a core dump in progress | |
542 | * for the old mm, we get out and die instead of going | |
543 | * through with the exec. We must hold mmap_sem around | |
544 | * checking core_waiters and changing tsk->mm. The | |
545 | * core-inducing thread will increment core_waiters for | |
546 | * each thread whose ->mm == old_mm. | |
547 | */ | |
548 | down_read(&old_mm->mmap_sem); | |
549 | if (unlikely(old_mm->core_waiters)) { | |
550 | up_read(&old_mm->mmap_sem); | |
551 | return -EINTR; | |
552 | } | |
553 | } | |
554 | task_lock(tsk); | |
555 | active_mm = tsk->active_mm; | |
556 | tsk->mm = mm; | |
557 | tsk->active_mm = mm; | |
558 | activate_mm(active_mm, mm); | |
559 | task_unlock(tsk); | |
560 | arch_pick_mmap_layout(mm); | |
561 | if (old_mm) { | |
562 | up_read(&old_mm->mmap_sem); | |
7dddb12c | 563 | BUG_ON(active_mm != old_mm); |
1da177e4 LT |
564 | mmput(old_mm); |
565 | return 0; | |
566 | } | |
567 | mmdrop(active_mm); | |
568 | return 0; | |
569 | } | |
570 | ||
571 | /* | |
572 | * This function makes sure the current process has its own signal table, | |
573 | * so that flush_signal_handlers can later reset the handlers without | |
574 | * disturbing other processes. (Other processes might share the signal | |
575 | * table via the CLONE_SIGHAND option to clone().) | |
576 | */ | |
858119e1 | 577 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
578 | { |
579 | struct signal_struct *sig = tsk->signal; | |
580 | struct sighand_struct *newsighand, *oldsighand = tsk->sighand; | |
581 | spinlock_t *lock = &oldsighand->siglock; | |
329f7dba | 582 | struct task_struct *leader = NULL; |
1da177e4 LT |
583 | int count; |
584 | ||
fba2afaa DL |
585 | /* |
586 | * Tell all the sighand listeners that this sighand has | |
587 | * been detached. The signalfd_detach() function grabs the | |
588 | * sighand lock, if signal listeners are present on the sighand. | |
589 | */ | |
590 | signalfd_detach(tsk); | |
591 | ||
1da177e4 LT |
592 | /* |
593 | * If we don't share sighandlers, then we aren't sharing anything | |
594 | * and we can just re-use it all. | |
595 | */ | |
596 | if (atomic_read(&oldsighand->count) <= 1) { | |
597 | BUG_ON(atomic_read(&sig->count) != 1); | |
598 | exit_itimers(sig); | |
599 | return 0; | |
600 | } | |
601 | ||
602 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); | |
603 | if (!newsighand) | |
604 | return -ENOMEM; | |
605 | ||
aafe6c2a | 606 | if (thread_group_empty(tsk)) |
1da177e4 LT |
607 | goto no_thread_group; |
608 | ||
609 | /* | |
610 | * Kill all other threads in the thread group. | |
611 | * We must hold tasklist_lock to call zap_other_threads. | |
612 | */ | |
613 | read_lock(&tasklist_lock); | |
614 | spin_lock_irq(lock); | |
615 | if (sig->flags & SIGNAL_GROUP_EXIT) { | |
616 | /* | |
617 | * Another group action in progress, just | |
618 | * return so that the signal is processed. | |
619 | */ | |
620 | spin_unlock_irq(lock); | |
621 | read_unlock(&tasklist_lock); | |
622 | kmem_cache_free(sighand_cachep, newsighand); | |
623 | return -EAGAIN; | |
624 | } | |
1434261c ON |
625 | |
626 | /* | |
627 | * child_reaper ignores SIGKILL, change it now. | |
628 | * Reparenting needs write_lock on tasklist_lock, | |
629 | * so it is safe to do it under read_lock. | |
630 | */ | |
84d73786 SB |
631 | if (unlikely(tsk->group_leader == child_reaper(tsk))) |
632 | tsk->nsproxy->pid_ns->child_reaper = tsk; | |
1434261c | 633 | |
aafe6c2a | 634 | zap_other_threads(tsk); |
1da177e4 LT |
635 | read_unlock(&tasklist_lock); |
636 | ||
637 | /* | |
638 | * Account for the thread group leader hanging around: | |
639 | */ | |
9e4e23bc | 640 | count = 1; |
aafe6c2a | 641 | if (!thread_group_leader(tsk)) { |
9e4e23bc | 642 | count = 2; |
53231250 RM |
643 | /* |
644 | * The SIGALRM timer survives the exec, but needs to point | |
645 | * at us as the new group leader now. We have a race with | |
646 | * a timer firing now getting the old leader, so we need to | |
647 | * synchronize with any firing (by calling del_timer_sync) | |
648 | * before we can safely let the old group leader die. | |
649 | */ | |
aafe6c2a | 650 | sig->tsk = tsk; |
932aeafb | 651 | spin_unlock_irq(lock); |
2ff678b8 TG |
652 | if (hrtimer_cancel(&sig->real_timer)) |
653 | hrtimer_restart(&sig->real_timer); | |
932aeafb | 654 | spin_lock_irq(lock); |
53231250 | 655 | } |
1da177e4 | 656 | while (atomic_read(&sig->count) > count) { |
aafe6c2a | 657 | sig->group_exit_task = tsk; |
1da177e4 LT |
658 | sig->notify_count = count; |
659 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
660 | spin_unlock_irq(lock); | |
661 | schedule(); | |
662 | spin_lock_irq(lock); | |
663 | } | |
664 | sig->group_exit_task = NULL; | |
665 | sig->notify_count = 0; | |
666 | spin_unlock_irq(lock); | |
667 | ||
668 | /* | |
669 | * At this point all other threads have exited, all we have to | |
670 | * do is to wait for the thread group leader to become inactive, | |
671 | * and to assume its PID: | |
672 | */ | |
aafe6c2a | 673 | if (!thread_group_leader(tsk)) { |
1da177e4 LT |
674 | /* |
675 | * Wait for the thread group leader to be a zombie. | |
676 | * It should already be zombie at this point, most | |
677 | * of the time. | |
678 | */ | |
aafe6c2a | 679 | leader = tsk->group_leader; |
1da177e4 LT |
680 | while (leader->exit_state != EXIT_ZOMBIE) |
681 | yield(); | |
682 | ||
f5e90281 RM |
683 | /* |
684 | * The only record we have of the real-time age of a | |
685 | * process, regardless of execs it's done, is start_time. | |
686 | * All the past CPU time is accumulated in signal_struct | |
687 | * from sister threads now dead. But in this non-leader | |
688 | * exec, nothing survives from the original leader thread, | |
689 | * whose birth marks the true age of this process now. | |
690 | * When we take on its identity by switching to its PID, we | |
691 | * also take its birthdate (always earlier than our own). | |
692 | */ | |
aafe6c2a | 693 | tsk->start_time = leader->start_time; |
f5e90281 | 694 | |
1da177e4 LT |
695 | write_lock_irq(&tasklist_lock); |
696 | ||
aafe6c2a EB |
697 | BUG_ON(leader->tgid != tsk->tgid); |
698 | BUG_ON(tsk->pid == tsk->tgid); | |
1da177e4 LT |
699 | /* |
700 | * An exec() starts a new thread group with the | |
701 | * TGID of the previous thread group. Rehash the | |
702 | * two threads with a switched PID, and release | |
703 | * the former thread group leader: | |
704 | */ | |
d73d6529 EB |
705 | |
706 | /* Become a process group leader with the old leader's pid. | |
c18258c6 EB |
707 | * The old leader becomes a thread of the this thread group. |
708 | * Note: The old leader also uses this pid until release_task | |
d73d6529 EB |
709 | * is called. Odd but simple and correct. |
710 | */ | |
aafe6c2a EB |
711 | detach_pid(tsk, PIDTYPE_PID); |
712 | tsk->pid = leader->pid; | |
e713d0da | 713 | attach_pid(tsk, PIDTYPE_PID, find_pid(tsk->pid)); |
aafe6c2a EB |
714 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
715 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
716 | list_replace_rcu(&leader->tasks, &tsk->tasks); | |
1da177e4 | 717 | |
aafe6c2a EB |
718 | tsk->group_leader = tsk; |
719 | leader->group_leader = tsk; | |
de12a787 | 720 | |
aafe6c2a | 721 | tsk->exit_signal = SIGCHLD; |
962b564c ON |
722 | |
723 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
724 | leader->exit_state = EXIT_DEAD; | |
1da177e4 LT |
725 | |
726 | write_unlock_irq(&tasklist_lock); | |
1da177e4 LT |
727 | } |
728 | ||
729 | /* | |
fb085cf1 AN |
730 | * There may be one thread left which is just exiting, |
731 | * but it's safe to stop telling the group to kill themselves. | |
1da177e4 LT |
732 | */ |
733 | sig->flags = 0; | |
734 | ||
735 | no_thread_group: | |
1da177e4 | 736 | exit_itimers(sig); |
329f7dba ON |
737 | if (leader) |
738 | release_task(leader); | |
739 | ||
740 | BUG_ON(atomic_read(&sig->count) != 1); | |
1da177e4 LT |
741 | |
742 | if (atomic_read(&oldsighand->count) == 1) { | |
743 | /* | |
744 | * Now that we nuked the rest of the thread group, | |
745 | * it turns out we are not sharing sighand any more either. | |
746 | * So we can just keep it. | |
747 | */ | |
748 | kmem_cache_free(sighand_cachep, newsighand); | |
749 | } else { | |
750 | /* | |
751 | * Move our state over to newsighand and switch it in. | |
752 | */ | |
1da177e4 LT |
753 | atomic_set(&newsighand->count, 1); |
754 | memcpy(newsighand->action, oldsighand->action, | |
755 | sizeof(newsighand->action)); | |
756 | ||
757 | write_lock_irq(&tasklist_lock); | |
758 | spin_lock(&oldsighand->siglock); | |
513627d7 | 759 | spin_lock_nested(&newsighand->siglock, SINGLE_DEPTH_NESTING); |
1da177e4 | 760 | |
aafe6c2a | 761 | rcu_assign_pointer(tsk->sighand, newsighand); |
1da177e4 LT |
762 | recalc_sigpending(); |
763 | ||
764 | spin_unlock(&newsighand->siglock); | |
765 | spin_unlock(&oldsighand->siglock); | |
766 | write_unlock_irq(&tasklist_lock); | |
767 | ||
fba2afaa | 768 | __cleanup_sighand(oldsighand); |
1da177e4 LT |
769 | } |
770 | ||
aafe6c2a | 771 | BUG_ON(!thread_group_leader(tsk)); |
1da177e4 LT |
772 | return 0; |
773 | } | |
774 | ||
775 | /* | |
776 | * These functions flushes out all traces of the currently running executable | |
777 | * so that a new one can be started | |
778 | */ | |
779 | ||
858119e1 | 780 | static void flush_old_files(struct files_struct * files) |
1da177e4 LT |
781 | { |
782 | long j = -1; | |
badf1662 | 783 | struct fdtable *fdt; |
1da177e4 LT |
784 | |
785 | spin_lock(&files->file_lock); | |
786 | for (;;) { | |
787 | unsigned long set, i; | |
788 | ||
789 | j++; | |
790 | i = j * __NFDBITS; | |
badf1662 | 791 | fdt = files_fdtable(files); |
bbea9f69 | 792 | if (i >= fdt->max_fds) |
1da177e4 | 793 | break; |
badf1662 | 794 | set = fdt->close_on_exec->fds_bits[j]; |
1da177e4 LT |
795 | if (!set) |
796 | continue; | |
badf1662 | 797 | fdt->close_on_exec->fds_bits[j] = 0; |
1da177e4 LT |
798 | spin_unlock(&files->file_lock); |
799 | for ( ; set ; i++,set >>= 1) { | |
800 | if (set & 1) { | |
801 | sys_close(i); | |
802 | } | |
803 | } | |
804 | spin_lock(&files->file_lock); | |
805 | ||
806 | } | |
807 | spin_unlock(&files->file_lock); | |
808 | } | |
809 | ||
810 | void get_task_comm(char *buf, struct task_struct *tsk) | |
811 | { | |
812 | /* buf must be at least sizeof(tsk->comm) in size */ | |
813 | task_lock(tsk); | |
814 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
815 | task_unlock(tsk); | |
816 | } | |
817 | ||
818 | void set_task_comm(struct task_struct *tsk, char *buf) | |
819 | { | |
820 | task_lock(tsk); | |
821 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); | |
822 | task_unlock(tsk); | |
823 | } | |
824 | ||
825 | int flush_old_exec(struct linux_binprm * bprm) | |
826 | { | |
827 | char * name; | |
828 | int i, ch, retval; | |
829 | struct files_struct *files; | |
830 | char tcomm[sizeof(current->comm)]; | |
831 | ||
832 | /* | |
833 | * Make sure we have a private signal table and that | |
834 | * we are unassociated from the previous thread group. | |
835 | */ | |
836 | retval = de_thread(current); | |
837 | if (retval) | |
838 | goto out; | |
839 | ||
840 | /* | |
841 | * Make sure we have private file handles. Ask the | |
842 | * fork helper to do the work for us and the exit | |
843 | * helper to do the cleanup of the old one. | |
844 | */ | |
845 | files = current->files; /* refcounted so safe to hold */ | |
846 | retval = unshare_files(); | |
847 | if (retval) | |
848 | goto out; | |
849 | /* | |
850 | * Release all of the old mmap stuff | |
851 | */ | |
852 | retval = exec_mmap(bprm->mm); | |
853 | if (retval) | |
854 | goto mmap_failed; | |
855 | ||
856 | bprm->mm = NULL; /* We're using it now */ | |
857 | ||
858 | /* This is the point of no return */ | |
1da177e4 LT |
859 | put_files_struct(files); |
860 | ||
861 | current->sas_ss_sp = current->sas_ss_size = 0; | |
862 | ||
863 | if (current->euid == current->uid && current->egid == current->gid) | |
864 | current->mm->dumpable = 1; | |
d6e71144 AC |
865 | else |
866 | current->mm->dumpable = suid_dumpable; | |
867 | ||
1da177e4 | 868 | name = bprm->filename; |
36772092 PBG |
869 | |
870 | /* Copies the binary name from after last slash */ | |
1da177e4 LT |
871 | for (i=0; (ch = *(name++)) != '\0';) { |
872 | if (ch == '/') | |
36772092 | 873 | i = 0; /* overwrite what we wrote */ |
1da177e4 LT |
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 | ||
0551fbd2 BH |
884 | /* Set the new mm task size. We have to do that late because it may |
885 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
886 | * some architectures like powerpc | |
887 | */ | |
888 | current->mm->task_size = TASK_SIZE; | |
889 | ||
1da177e4 | 890 | if (bprm->e_uid != current->euid || bprm->e_gid != current->egid || |
8c744fb8 | 891 | file_permission(bprm->file, MAY_READ) || |
1da177e4 LT |
892 | (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { |
893 | suid_keys(current); | |
d6e71144 | 894 | current->mm->dumpable = suid_dumpable; |
1da177e4 LT |
895 | } |
896 | ||
897 | /* An exec changes our domain. We are no longer part of the thread | |
898 | group */ | |
899 | ||
900 | current->self_exec_id++; | |
901 | ||
902 | flush_signal_handlers(current, 0); | |
903 | flush_old_files(current->files); | |
904 | ||
905 | return 0; | |
906 | ||
907 | mmap_failed: | |
3b9b8ab6 | 908 | reset_files_struct(current, files); |
1da177e4 LT |
909 | out: |
910 | return retval; | |
911 | } | |
912 | ||
913 | EXPORT_SYMBOL(flush_old_exec); | |
914 | ||
915 | /* | |
916 | * Fill the binprm structure from the inode. | |
917 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
918 | */ | |
919 | int prepare_binprm(struct linux_binprm *bprm) | |
920 | { | |
921 | int mode; | |
0f7fc9e4 | 922 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
923 | int retval; |
924 | ||
925 | mode = inode->i_mode; | |
1da177e4 LT |
926 | if (bprm->file->f_op == NULL) |
927 | return -EACCES; | |
928 | ||
929 | bprm->e_uid = current->euid; | |
930 | bprm->e_gid = current->egid; | |
931 | ||
0f7fc9e4 | 932 | if(!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
1da177e4 LT |
933 | /* Set-uid? */ |
934 | if (mode & S_ISUID) { | |
935 | current->personality &= ~PER_CLEAR_ON_SETID; | |
936 | bprm->e_uid = inode->i_uid; | |
937 | } | |
938 | ||
939 | /* Set-gid? */ | |
940 | /* | |
941 | * If setgid is set but no group execute bit then this | |
942 | * is a candidate for mandatory locking, not a setgid | |
943 | * executable. | |
944 | */ | |
945 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
946 | current->personality &= ~PER_CLEAR_ON_SETID; | |
947 | bprm->e_gid = inode->i_gid; | |
948 | } | |
949 | } | |
950 | ||
951 | /* fill in binprm security blob */ | |
952 | retval = security_bprm_set(bprm); | |
953 | if (retval) | |
954 | return retval; | |
955 | ||
956 | memset(bprm->buf,0,BINPRM_BUF_SIZE); | |
957 | return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE); | |
958 | } | |
959 | ||
960 | EXPORT_SYMBOL(prepare_binprm); | |
961 | ||
858119e1 | 962 | static int unsafe_exec(struct task_struct *p) |
1da177e4 LT |
963 | { |
964 | int unsafe = 0; | |
965 | if (p->ptrace & PT_PTRACED) { | |
966 | if (p->ptrace & PT_PTRACE_CAP) | |
967 | unsafe |= LSM_UNSAFE_PTRACE_CAP; | |
968 | else | |
969 | unsafe |= LSM_UNSAFE_PTRACE; | |
970 | } | |
971 | if (atomic_read(&p->fs->count) > 1 || | |
972 | atomic_read(&p->files->count) > 1 || | |
973 | atomic_read(&p->sighand->count) > 1) | |
974 | unsafe |= LSM_UNSAFE_SHARE; | |
975 | ||
976 | return unsafe; | |
977 | } | |
978 | ||
979 | void compute_creds(struct linux_binprm *bprm) | |
980 | { | |
981 | int unsafe; | |
982 | ||
983 | if (bprm->e_uid != current->uid) | |
984 | suid_keys(current); | |
985 | exec_keys(current); | |
986 | ||
987 | task_lock(current); | |
988 | unsafe = unsafe_exec(current); | |
989 | security_bprm_apply_creds(bprm, unsafe); | |
990 | task_unlock(current); | |
991 | security_bprm_post_apply_creds(bprm); | |
992 | } | |
1da177e4 LT |
993 | EXPORT_SYMBOL(compute_creds); |
994 | ||
4fc75ff4 NP |
995 | /* |
996 | * Arguments are '\0' separated strings found at the location bprm->p | |
997 | * points to; chop off the first by relocating brpm->p to right after | |
998 | * the first '\0' encountered. | |
999 | */ | |
1da177e4 LT |
1000 | void remove_arg_zero(struct linux_binprm *bprm) |
1001 | { | |
1002 | if (bprm->argc) { | |
4fc75ff4 NP |
1003 | char ch; |
1004 | ||
1005 | do { | |
1006 | unsigned long offset; | |
1007 | unsigned long index; | |
1008 | char *kaddr; | |
1009 | struct page *page; | |
1da177e4 | 1010 | |
4fc75ff4 NP |
1011 | offset = bprm->p & ~PAGE_MASK; |
1012 | index = bprm->p >> PAGE_SHIFT; | |
1da177e4 | 1013 | |
4fc75ff4 | 1014 | page = bprm->page[index]; |
1da177e4 | 1015 | kaddr = kmap_atomic(page, KM_USER0); |
4fc75ff4 NP |
1016 | |
1017 | /* run through page until we reach end or find NUL */ | |
1018 | do { | |
1019 | ch = *(kaddr + offset); | |
1020 | ||
1021 | /* discard that character... */ | |
1022 | bprm->p++; | |
1023 | offset++; | |
1024 | } while (offset < PAGE_SIZE && ch != '\0'); | |
1025 | ||
1026 | kunmap_atomic(kaddr, KM_USER0); | |
1027 | ||
1028 | /* free the old page */ | |
1029 | if (offset == PAGE_SIZE) { | |
1030 | __free_page(page); | |
1031 | bprm->page[index] = NULL; | |
1032 | } | |
1033 | } while (ch != '\0'); | |
1034 | ||
1da177e4 LT |
1035 | bprm->argc--; |
1036 | } | |
1037 | } | |
1da177e4 LT |
1038 | EXPORT_SYMBOL(remove_arg_zero); |
1039 | ||
1040 | /* | |
1041 | * cycle the list of binary formats handler, until one recognizes the image | |
1042 | */ | |
1043 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1044 | { | |
1045 | int try,retval; | |
1046 | struct linux_binfmt *fmt; | |
1047 | #ifdef __alpha__ | |
1048 | /* handle /sbin/loader.. */ | |
1049 | { | |
1050 | struct exec * eh = (struct exec *) bprm->buf; | |
1051 | ||
1052 | if (!bprm->loader && eh->fh.f_magic == 0x183 && | |
1053 | (eh->fh.f_flags & 0x3000) == 0x3000) | |
1054 | { | |
1055 | struct file * file; | |
1056 | unsigned long loader; | |
1057 | ||
1058 | allow_write_access(bprm->file); | |
1059 | fput(bprm->file); | |
1060 | bprm->file = NULL; | |
1061 | ||
1062 | loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); | |
1063 | ||
1064 | file = open_exec("/sbin/loader"); | |
1065 | retval = PTR_ERR(file); | |
1066 | if (IS_ERR(file)) | |
1067 | return retval; | |
1068 | ||
1069 | /* Remember if the application is TASO. */ | |
1070 | bprm->sh_bang = eh->ah.entry < 0x100000000UL; | |
1071 | ||
1072 | bprm->file = file; | |
1073 | bprm->loader = loader; | |
1074 | retval = prepare_binprm(bprm); | |
1075 | if (retval<0) | |
1076 | return retval; | |
1077 | /* should call search_binary_handler recursively here, | |
1078 | but it does not matter */ | |
1079 | } | |
1080 | } | |
1081 | #endif | |
1082 | retval = security_bprm_check(bprm); | |
1083 | if (retval) | |
1084 | return retval; | |
1085 | ||
1086 | /* kernel module loader fixup */ | |
1087 | /* so we don't try to load run modprobe in kernel space. */ | |
1088 | set_fs(USER_DS); | |
473ae30b AV |
1089 | |
1090 | retval = audit_bprm(bprm); | |
1091 | if (retval) | |
1092 | return retval; | |
1093 | ||
1da177e4 LT |
1094 | retval = -ENOENT; |
1095 | for (try=0; try<2; try++) { | |
1096 | read_lock(&binfmt_lock); | |
1097 | for (fmt = formats ; fmt ; fmt = fmt->next) { | |
1098 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; | |
1099 | if (!fn) | |
1100 | continue; | |
1101 | if (!try_module_get(fmt->module)) | |
1102 | continue; | |
1103 | read_unlock(&binfmt_lock); | |
1104 | retval = fn(bprm, regs); | |
1105 | if (retval >= 0) { | |
1106 | put_binfmt(fmt); | |
1107 | allow_write_access(bprm->file); | |
1108 | if (bprm->file) | |
1109 | fput(bprm->file); | |
1110 | bprm->file = NULL; | |
1111 | current->did_exec = 1; | |
9f46080c | 1112 | proc_exec_connector(current); |
1da177e4 LT |
1113 | return retval; |
1114 | } | |
1115 | read_lock(&binfmt_lock); | |
1116 | put_binfmt(fmt); | |
1117 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1118 | break; | |
1119 | if (!bprm->file) { | |
1120 | read_unlock(&binfmt_lock); | |
1121 | return retval; | |
1122 | } | |
1123 | } | |
1124 | read_unlock(&binfmt_lock); | |
1125 | if (retval != -ENOEXEC || bprm->mm == NULL) { | |
1126 | break; | |
1127 | #ifdef CONFIG_KMOD | |
1128 | }else{ | |
1129 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) | |
1130 | if (printable(bprm->buf[0]) && | |
1131 | printable(bprm->buf[1]) && | |
1132 | printable(bprm->buf[2]) && | |
1133 | printable(bprm->buf[3])) | |
1134 | break; /* -ENOEXEC */ | |
1135 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); | |
1136 | #endif | |
1137 | } | |
1138 | } | |
1139 | return retval; | |
1140 | } | |
1141 | ||
1142 | EXPORT_SYMBOL(search_binary_handler); | |
1143 | ||
1144 | /* | |
1145 | * sys_execve() executes a new program. | |
1146 | */ | |
1147 | int do_execve(char * filename, | |
1148 | char __user *__user *argv, | |
1149 | char __user *__user *envp, | |
1150 | struct pt_regs * regs) | |
1151 | { | |
1152 | struct linux_binprm *bprm; | |
1153 | struct file *file; | |
1154 | int retval; | |
1155 | int i; | |
1156 | ||
1157 | retval = -ENOMEM; | |
11b0b5ab | 1158 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1da177e4 LT |
1159 | if (!bprm) |
1160 | goto out_ret; | |
1da177e4 LT |
1161 | |
1162 | file = open_exec(filename); | |
1163 | retval = PTR_ERR(file); | |
1164 | if (IS_ERR(file)) | |
1165 | goto out_kfree; | |
1166 | ||
1167 | sched_exec(); | |
1168 | ||
1169 | bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); | |
1170 | ||
1171 | bprm->file = file; | |
1172 | bprm->filename = filename; | |
1173 | bprm->interp = filename; | |
1174 | bprm->mm = mm_alloc(); | |
1175 | retval = -ENOMEM; | |
1176 | if (!bprm->mm) | |
1177 | goto out_file; | |
1178 | ||
1179 | retval = init_new_context(current, bprm->mm); | |
1180 | if (retval < 0) | |
1181 | goto out_mm; | |
1182 | ||
1183 | bprm->argc = count(argv, bprm->p / sizeof(void *)); | |
1184 | if ((retval = bprm->argc) < 0) | |
1185 | goto out_mm; | |
1186 | ||
1187 | bprm->envc = count(envp, bprm->p / sizeof(void *)); | |
1188 | if ((retval = bprm->envc) < 0) | |
1189 | goto out_mm; | |
1190 | ||
1191 | retval = security_bprm_alloc(bprm); | |
1192 | if (retval) | |
1193 | goto out; | |
1194 | ||
1195 | retval = prepare_binprm(bprm); | |
1196 | if (retval < 0) | |
1197 | goto out; | |
1198 | ||
1199 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1200 | if (retval < 0) | |
1201 | goto out; | |
1202 | ||
1203 | bprm->exec = bprm->p; | |
1204 | retval = copy_strings(bprm->envc, envp, bprm); | |
1205 | if (retval < 0) | |
1206 | goto out; | |
1207 | ||
1208 | retval = copy_strings(bprm->argc, argv, bprm); | |
1209 | if (retval < 0) | |
1210 | goto out; | |
1211 | ||
1212 | retval = search_binary_handler(bprm,regs); | |
1213 | if (retval >= 0) { | |
1214 | free_arg_pages(bprm); | |
1215 | ||
1216 | /* execve success */ | |
1217 | security_bprm_free(bprm); | |
1218 | acct_update_integrals(current); | |
1da177e4 LT |
1219 | kfree(bprm); |
1220 | return retval; | |
1221 | } | |
1222 | ||
1223 | out: | |
1224 | /* Something went wrong, return the inode and free the argument pages*/ | |
1225 | for (i = 0 ; i < MAX_ARG_PAGES ; i++) { | |
1226 | struct page * page = bprm->page[i]; | |
1227 | if (page) | |
1228 | __free_page(page); | |
1229 | } | |
1230 | ||
1231 | if (bprm->security) | |
1232 | security_bprm_free(bprm); | |
1233 | ||
1234 | out_mm: | |
1235 | if (bprm->mm) | |
1236 | mmdrop(bprm->mm); | |
1237 | ||
1238 | out_file: | |
1239 | if (bprm->file) { | |
1240 | allow_write_access(bprm->file); | |
1241 | fput(bprm->file); | |
1242 | } | |
1243 | ||
1244 | out_kfree: | |
1245 | kfree(bprm); | |
1246 | ||
1247 | out_ret: | |
1248 | return retval; | |
1249 | } | |
1250 | ||
1251 | int set_binfmt(struct linux_binfmt *new) | |
1252 | { | |
1253 | struct linux_binfmt *old = current->binfmt; | |
1254 | ||
1255 | if (new) { | |
1256 | if (!try_module_get(new->module)) | |
1257 | return -1; | |
1258 | } | |
1259 | current->binfmt = new; | |
1260 | if (old) | |
1261 | module_put(old->module); | |
1262 | return 0; | |
1263 | } | |
1264 | ||
1265 | EXPORT_SYMBOL(set_binfmt); | |
1266 | ||
1267 | #define CORENAME_MAX_SIZE 64 | |
1268 | ||
1269 | /* format_corename will inspect the pattern parameter, and output a | |
1270 | * name into corename, which must have space for at least | |
1271 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
1272 | */ | |
c4bbafda | 1273 | static int format_corename(char *corename, const char *pattern, long signr) |
1da177e4 LT |
1274 | { |
1275 | const char *pat_ptr = pattern; | |
1276 | char *out_ptr = corename; | |
1277 | char *const out_end = corename + CORENAME_MAX_SIZE; | |
1278 | int rc; | |
1279 | int pid_in_pattern = 0; | |
c4bbafda AC |
1280 | int ispipe = 0; |
1281 | ||
1282 | if (*pattern == '|') | |
1283 | ispipe = 1; | |
1da177e4 LT |
1284 | |
1285 | /* Repeat as long as we have more pattern to process and more output | |
1286 | space */ | |
1287 | while (*pat_ptr) { | |
1288 | if (*pat_ptr != '%') { | |
1289 | if (out_ptr == out_end) | |
1290 | goto out; | |
1291 | *out_ptr++ = *pat_ptr++; | |
1292 | } else { | |
1293 | switch (*++pat_ptr) { | |
1294 | case 0: | |
1295 | goto out; | |
1296 | /* Double percent, output one percent */ | |
1297 | case '%': | |
1298 | if (out_ptr == out_end) | |
1299 | goto out; | |
1300 | *out_ptr++ = '%'; | |
1301 | break; | |
1302 | /* pid */ | |
1303 | case 'p': | |
1304 | pid_in_pattern = 1; | |
1305 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1306 | "%d", current->tgid); | |
1307 | if (rc > out_end - out_ptr) | |
1308 | goto out; | |
1309 | out_ptr += rc; | |
1310 | break; | |
1311 | /* uid */ | |
1312 | case 'u': | |
1313 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1314 | "%d", current->uid); | |
1315 | if (rc > out_end - out_ptr) | |
1316 | goto out; | |
1317 | out_ptr += rc; | |
1318 | break; | |
1319 | /* gid */ | |
1320 | case 'g': | |
1321 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1322 | "%d", current->gid); | |
1323 | if (rc > out_end - out_ptr) | |
1324 | goto out; | |
1325 | out_ptr += rc; | |
1326 | break; | |
1327 | /* signal that caused the coredump */ | |
1328 | case 's': | |
1329 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1330 | "%ld", signr); | |
1331 | if (rc > out_end - out_ptr) | |
1332 | goto out; | |
1333 | out_ptr += rc; | |
1334 | break; | |
1335 | /* UNIX time of coredump */ | |
1336 | case 't': { | |
1337 | struct timeval tv; | |
1338 | do_gettimeofday(&tv); | |
1339 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1340 | "%lu", tv.tv_sec); | |
1341 | if (rc > out_end - out_ptr) | |
1342 | goto out; | |
1343 | out_ptr += rc; | |
1344 | break; | |
1345 | } | |
1346 | /* hostname */ | |
1347 | case 'h': | |
1348 | down_read(&uts_sem); | |
1349 | rc = snprintf(out_ptr, out_end - out_ptr, | |
e9ff3990 | 1350 | "%s", utsname()->nodename); |
1da177e4 LT |
1351 | up_read(&uts_sem); |
1352 | if (rc > out_end - out_ptr) | |
1353 | goto out; | |
1354 | out_ptr += rc; | |
1355 | break; | |
1356 | /* executable */ | |
1357 | case 'e': | |
1358 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1359 | "%s", current->comm); | |
1360 | if (rc > out_end - out_ptr) | |
1361 | goto out; | |
1362 | out_ptr += rc; | |
1363 | break; | |
1364 | default: | |
1365 | break; | |
1366 | } | |
1367 | ++pat_ptr; | |
1368 | } | |
1369 | } | |
1370 | /* Backward compatibility with core_uses_pid: | |
1371 | * | |
1372 | * If core_pattern does not include a %p (as is the default) | |
1373 | * and core_uses_pid is set, then .%pid will be appended to | |
c4bbafda AC |
1374 | * the filename. Do not do this for piped commands. */ |
1375 | if (!ispipe && !pid_in_pattern | |
1da177e4 LT |
1376 | && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) { |
1377 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1378 | ".%d", current->tgid); | |
1379 | if (rc > out_end - out_ptr) | |
1380 | goto out; | |
1381 | out_ptr += rc; | |
1382 | } | |
c4bbafda | 1383 | out: |
1da177e4 | 1384 | *out_ptr = 0; |
c4bbafda | 1385 | return ispipe; |
1da177e4 LT |
1386 | } |
1387 | ||
d5f70c00 | 1388 | static void zap_process(struct task_struct *start) |
aceecc04 ON |
1389 | { |
1390 | struct task_struct *t; | |
281de339 | 1391 | |
d5f70c00 ON |
1392 | start->signal->flags = SIGNAL_GROUP_EXIT; |
1393 | start->signal->group_stop_count = 0; | |
aceecc04 ON |
1394 | |
1395 | t = start; | |
1396 | do { | |
1397 | if (t != current && t->mm) { | |
1398 | t->mm->core_waiters++; | |
281de339 ON |
1399 | sigaddset(&t->pending.signal, SIGKILL); |
1400 | signal_wake_up(t, 1); | |
aceecc04 ON |
1401 | } |
1402 | } while ((t = next_thread(t)) != start); | |
1403 | } | |
1404 | ||
dcf560c5 ON |
1405 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
1406 | int exit_code) | |
1da177e4 LT |
1407 | { |
1408 | struct task_struct *g, *p; | |
5debfa6d | 1409 | unsigned long flags; |
dcf560c5 ON |
1410 | int err = -EAGAIN; |
1411 | ||
1412 | spin_lock_irq(&tsk->sighand->siglock); | |
1413 | if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) { | |
dcf560c5 | 1414 | tsk->signal->group_exit_code = exit_code; |
5debfa6d | 1415 | zap_process(tsk); |
dcf560c5 | 1416 | err = 0; |
1da177e4 | 1417 | } |
dcf560c5 ON |
1418 | spin_unlock_irq(&tsk->sighand->siglock); |
1419 | if (err) | |
1420 | return err; | |
1da177e4 | 1421 | |
5debfa6d ON |
1422 | if (atomic_read(&mm->mm_users) == mm->core_waiters + 1) |
1423 | goto done; | |
1424 | ||
7b1c6154 | 1425 | rcu_read_lock(); |
aceecc04 | 1426 | for_each_process(g) { |
5debfa6d ON |
1427 | if (g == tsk->group_leader) |
1428 | continue; | |
1429 | ||
aceecc04 ON |
1430 | p = g; |
1431 | do { | |
1432 | if (p->mm) { | |
5debfa6d ON |
1433 | if (p->mm == mm) { |
1434 | /* | |
1435 | * p->sighand can't disappear, but | |
1436 | * may be changed by de_thread() | |
1437 | */ | |
1438 | lock_task_sighand(p, &flags); | |
d5f70c00 | 1439 | zap_process(p); |
5debfa6d ON |
1440 | unlock_task_sighand(p, &flags); |
1441 | } | |
aceecc04 ON |
1442 | break; |
1443 | } | |
1444 | } while ((p = next_thread(p)) != g); | |
1445 | } | |
7b1c6154 | 1446 | rcu_read_unlock(); |
5debfa6d | 1447 | done: |
dcf560c5 | 1448 | return mm->core_waiters; |
1da177e4 LT |
1449 | } |
1450 | ||
dcf560c5 | 1451 | static int coredump_wait(int exit_code) |
1da177e4 | 1452 | { |
dcf560c5 ON |
1453 | struct task_struct *tsk = current; |
1454 | struct mm_struct *mm = tsk->mm; | |
1455 | struct completion startup_done; | |
1456 | struct completion *vfork_done; | |
2384f55f | 1457 | int core_waiters; |
1da177e4 | 1458 | |
dcf560c5 ON |
1459 | init_completion(&mm->core_done); |
1460 | init_completion(&startup_done); | |
1da177e4 LT |
1461 | mm->core_startup_done = &startup_done; |
1462 | ||
dcf560c5 | 1463 | core_waiters = zap_threads(tsk, mm, exit_code); |
2384f55f ON |
1464 | up_write(&mm->mmap_sem); |
1465 | ||
dcf560c5 ON |
1466 | if (unlikely(core_waiters < 0)) |
1467 | goto fail; | |
1468 | ||
1469 | /* | |
1470 | * Make sure nobody is waiting for us to release the VM, | |
1471 | * otherwise we can deadlock when we wait on each other | |
1472 | */ | |
1473 | vfork_done = tsk->vfork_done; | |
1474 | if (vfork_done) { | |
1475 | tsk->vfork_done = NULL; | |
1476 | complete(vfork_done); | |
1477 | } | |
1478 | ||
2384f55f | 1479 | if (core_waiters) |
1da177e4 | 1480 | wait_for_completion(&startup_done); |
dcf560c5 | 1481 | fail: |
1da177e4 | 1482 | BUG_ON(mm->core_waiters); |
dcf560c5 | 1483 | return core_waiters; |
1da177e4 LT |
1484 | } |
1485 | ||
1486 | int do_coredump(long signr, int exit_code, struct pt_regs * regs) | |
1487 | { | |
1488 | char corename[CORENAME_MAX_SIZE + 1]; | |
1489 | struct mm_struct *mm = current->mm; | |
1490 | struct linux_binfmt * binfmt; | |
1491 | struct inode * inode; | |
1492 | struct file * file; | |
1493 | int retval = 0; | |
d6e71144 AC |
1494 | int fsuid = current->fsuid; |
1495 | int flag = 0; | |
d025c9db | 1496 | int ispipe = 0; |
1da177e4 | 1497 | |
0a4ff8c2 SG |
1498 | audit_core_dumps(signr); |
1499 | ||
1da177e4 LT |
1500 | binfmt = current->binfmt; |
1501 | if (!binfmt || !binfmt->core_dump) | |
1502 | goto fail; | |
1503 | down_write(&mm->mmap_sem); | |
1504 | if (!mm->dumpable) { | |
1505 | up_write(&mm->mmap_sem); | |
1506 | goto fail; | |
1507 | } | |
d6e71144 AC |
1508 | |
1509 | /* | |
1510 | * We cannot trust fsuid as being the "true" uid of the | |
1511 | * process nor do we know its entire history. We only know it | |
1512 | * was tainted so we dump it as root in mode 2. | |
1513 | */ | |
1514 | if (mm->dumpable == 2) { /* Setuid core dump mode */ | |
1515 | flag = O_EXCL; /* Stop rewrite attacks */ | |
1516 | current->fsuid = 0; /* Dump root private */ | |
1517 | } | |
1da177e4 | 1518 | mm->dumpable = 0; |
1291cf41 | 1519 | |
dcf560c5 ON |
1520 | retval = coredump_wait(exit_code); |
1521 | if (retval < 0) | |
1291cf41 | 1522 | goto fail; |
1da177e4 LT |
1523 | |
1524 | /* | |
1525 | * Clear any false indication of pending signals that might | |
1526 | * be seen by the filesystem code called to write the core file. | |
1527 | */ | |
1da177e4 LT |
1528 | clear_thread_flag(TIF_SIGPENDING); |
1529 | ||
1530 | if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump) | |
1531 | goto fail_unlock; | |
1532 | ||
1533 | /* | |
1534 | * lock_kernel() because format_corename() is controlled by sysctl, which | |
1535 | * uses lock_kernel() | |
1536 | */ | |
1537 | lock_kernel(); | |
c4bbafda | 1538 | ispipe = format_corename(corename, core_pattern, signr); |
1da177e4 | 1539 | unlock_kernel(); |
c4bbafda | 1540 | if (ispipe) { |
d025c9db AK |
1541 | /* SIGPIPE can happen, but it's just never processed */ |
1542 | if(call_usermodehelper_pipe(corename+1, NULL, NULL, &file)) { | |
1543 | printk(KERN_INFO "Core dump to %s pipe failed\n", | |
1544 | corename); | |
1545 | goto fail_unlock; | |
1546 | } | |
d025c9db AK |
1547 | } else |
1548 | file = filp_open(corename, | |
6d4df677 AD |
1549 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
1550 | 0600); | |
1da177e4 LT |
1551 | if (IS_ERR(file)) |
1552 | goto fail_unlock; | |
0f7fc9e4 | 1553 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1554 | if (inode->i_nlink > 1) |
1555 | goto close_fail; /* multiple links - don't dump */ | |
0f7fc9e4 | 1556 | if (!ispipe && d_unhashed(file->f_path.dentry)) |
1da177e4 LT |
1557 | goto close_fail; |
1558 | ||
d025c9db AK |
1559 | /* AK: actually i see no reason to not allow this for named pipes etc., |
1560 | but keep the previous behaviour for now. */ | |
1561 | if (!ispipe && !S_ISREG(inode->i_mode)) | |
1da177e4 LT |
1562 | goto close_fail; |
1563 | if (!file->f_op) | |
1564 | goto close_fail; | |
1565 | if (!file->f_op->write) | |
1566 | goto close_fail; | |
0f7fc9e4 | 1567 | if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0) |
1da177e4 LT |
1568 | goto close_fail; |
1569 | ||
1570 | retval = binfmt->core_dump(signr, regs, file); | |
1571 | ||
1572 | if (retval) | |
1573 | current->signal->group_exit_code |= 0x80; | |
1574 | close_fail: | |
1575 | filp_close(file, NULL); | |
1576 | fail_unlock: | |
d6e71144 | 1577 | current->fsuid = fsuid; |
1da177e4 LT |
1578 | complete_all(&mm->core_done); |
1579 | fail: | |
1580 | return retval; | |
1581 | } |