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1da177e4 LT |
1 | /* |
2 | * linux/kernel/sys.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
1da177e4 LT |
7 | #include <linux/module.h> |
8 | #include <linux/mm.h> | |
9 | #include <linux/utsname.h> | |
10 | #include <linux/mman.h> | |
11 | #include <linux/smp_lock.h> | |
12 | #include <linux/notifier.h> | |
13 | #include <linux/reboot.h> | |
14 | #include <linux/prctl.h> | |
1da177e4 LT |
15 | #include <linux/highuid.h> |
16 | #include <linux/fs.h> | |
dc009d92 EB |
17 | #include <linux/kernel.h> |
18 | #include <linux/kexec.h> | |
1da177e4 | 19 | #include <linux/workqueue.h> |
c59ede7b | 20 | #include <linux/capability.h> |
1da177e4 LT |
21 | #include <linux/device.h> |
22 | #include <linux/key.h> | |
23 | #include <linux/times.h> | |
24 | #include <linux/posix-timers.h> | |
25 | #include <linux/security.h> | |
26 | #include <linux/dcookies.h> | |
27 | #include <linux/suspend.h> | |
28 | #include <linux/tty.h> | |
7ed20e1a | 29 | #include <linux/signal.h> |
9f46080c | 30 | #include <linux/cn_proc.h> |
3cfc348b | 31 | #include <linux/getcpu.h> |
1da177e4 LT |
32 | |
33 | #include <linux/compat.h> | |
34 | #include <linux/syscalls.h> | |
00d7c05a | 35 | #include <linux/kprobes.h> |
1da177e4 LT |
36 | |
37 | #include <asm/uaccess.h> | |
38 | #include <asm/io.h> | |
39 | #include <asm/unistd.h> | |
40 | ||
41 | #ifndef SET_UNALIGN_CTL | |
42 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) | |
43 | #endif | |
44 | #ifndef GET_UNALIGN_CTL | |
45 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) | |
46 | #endif | |
47 | #ifndef SET_FPEMU_CTL | |
48 | # define SET_FPEMU_CTL(a,b) (-EINVAL) | |
49 | #endif | |
50 | #ifndef GET_FPEMU_CTL | |
51 | # define GET_FPEMU_CTL(a,b) (-EINVAL) | |
52 | #endif | |
53 | #ifndef SET_FPEXC_CTL | |
54 | # define SET_FPEXC_CTL(a,b) (-EINVAL) | |
55 | #endif | |
56 | #ifndef GET_FPEXC_CTL | |
57 | # define GET_FPEXC_CTL(a,b) (-EINVAL) | |
58 | #endif | |
651d765d AB |
59 | #ifndef GET_ENDIAN |
60 | # define GET_ENDIAN(a,b) (-EINVAL) | |
61 | #endif | |
62 | #ifndef SET_ENDIAN | |
63 | # define SET_ENDIAN(a,b) (-EINVAL) | |
64 | #endif | |
1da177e4 LT |
65 | |
66 | /* | |
67 | * this is where the system-wide overflow UID and GID are defined, for | |
68 | * architectures that now have 32-bit UID/GID but didn't in the past | |
69 | */ | |
70 | ||
71 | int overflowuid = DEFAULT_OVERFLOWUID; | |
72 | int overflowgid = DEFAULT_OVERFLOWGID; | |
73 | ||
74 | #ifdef CONFIG_UID16 | |
75 | EXPORT_SYMBOL(overflowuid); | |
76 | EXPORT_SYMBOL(overflowgid); | |
77 | #endif | |
78 | ||
79 | /* | |
80 | * the same as above, but for filesystems which can only store a 16-bit | |
81 | * UID and GID. as such, this is needed on all architectures | |
82 | */ | |
83 | ||
84 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; | |
85 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; | |
86 | ||
87 | EXPORT_SYMBOL(fs_overflowuid); | |
88 | EXPORT_SYMBOL(fs_overflowgid); | |
89 | ||
90 | /* | |
91 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes | |
92 | */ | |
93 | ||
94 | int C_A_D = 1; | |
9ec52099 CLG |
95 | struct pid *cad_pid; |
96 | EXPORT_SYMBOL(cad_pid); | |
1da177e4 LT |
97 | |
98 | /* | |
99 | * Notifier list for kernel code which wants to be called | |
100 | * at shutdown. This is used to stop any idling DMA operations | |
101 | * and the like. | |
102 | */ | |
103 | ||
e041c683 AS |
104 | static BLOCKING_NOTIFIER_HEAD(reboot_notifier_list); |
105 | ||
106 | /* | |
107 | * Notifier chain core routines. The exported routines below | |
108 | * are layered on top of these, with appropriate locking added. | |
109 | */ | |
110 | ||
111 | static int notifier_chain_register(struct notifier_block **nl, | |
112 | struct notifier_block *n) | |
113 | { | |
114 | while ((*nl) != NULL) { | |
115 | if (n->priority > (*nl)->priority) | |
116 | break; | |
117 | nl = &((*nl)->next); | |
118 | } | |
119 | n->next = *nl; | |
120 | rcu_assign_pointer(*nl, n); | |
121 | return 0; | |
122 | } | |
123 | ||
124 | static int notifier_chain_unregister(struct notifier_block **nl, | |
125 | struct notifier_block *n) | |
126 | { | |
127 | while ((*nl) != NULL) { | |
128 | if ((*nl) == n) { | |
129 | rcu_assign_pointer(*nl, n->next); | |
130 | return 0; | |
131 | } | |
132 | nl = &((*nl)->next); | |
133 | } | |
134 | return -ENOENT; | |
135 | } | |
136 | ||
137 | static int __kprobes notifier_call_chain(struct notifier_block **nl, | |
138 | unsigned long val, void *v) | |
139 | { | |
140 | int ret = NOTIFY_DONE; | |
bbb1747d | 141 | struct notifier_block *nb, *next_nb; |
e041c683 AS |
142 | |
143 | nb = rcu_dereference(*nl); | |
144 | while (nb) { | |
bbb1747d | 145 | next_nb = rcu_dereference(nb->next); |
e041c683 AS |
146 | ret = nb->notifier_call(nb, val, v); |
147 | if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK) | |
148 | break; | |
bbb1747d | 149 | nb = next_nb; |
e041c683 AS |
150 | } |
151 | return ret; | |
152 | } | |
153 | ||
154 | /* | |
155 | * Atomic notifier chain routines. Registration and unregistration | |
eabc0694 | 156 | * use a spinlock, and call_chain is synchronized by RCU (no locks). |
e041c683 | 157 | */ |
1da177e4 LT |
158 | |
159 | /** | |
e041c683 AS |
160 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain |
161 | * @nh: Pointer to head of the atomic notifier chain | |
1da177e4 LT |
162 | * @n: New entry in notifier chain |
163 | * | |
e041c683 | 164 | * Adds a notifier to an atomic notifier chain. |
1da177e4 LT |
165 | * |
166 | * Currently always returns zero. | |
167 | */ | |
e041c683 AS |
168 | |
169 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
170 | struct notifier_block *n) | |
171 | { | |
172 | unsigned long flags; | |
173 | int ret; | |
174 | ||
175 | spin_lock_irqsave(&nh->lock, flags); | |
176 | ret = notifier_chain_register(&nh->head, n); | |
177 | spin_unlock_irqrestore(&nh->lock, flags); | |
178 | return ret; | |
179 | } | |
180 | ||
181 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
182 | ||
183 | /** | |
184 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
185 | * @nh: Pointer to head of the atomic notifier chain | |
186 | * @n: Entry to remove from notifier chain | |
187 | * | |
188 | * Removes a notifier from an atomic notifier chain. | |
189 | * | |
190 | * Returns zero on success or %-ENOENT on failure. | |
191 | */ | |
192 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
193 | struct notifier_block *n) | |
194 | { | |
195 | unsigned long flags; | |
196 | int ret; | |
197 | ||
198 | spin_lock_irqsave(&nh->lock, flags); | |
199 | ret = notifier_chain_unregister(&nh->head, n); | |
200 | spin_unlock_irqrestore(&nh->lock, flags); | |
201 | synchronize_rcu(); | |
202 | return ret; | |
203 | } | |
204 | ||
205 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
206 | ||
207 | /** | |
208 | * atomic_notifier_call_chain - Call functions in an atomic notifier chain | |
209 | * @nh: Pointer to head of the atomic notifier chain | |
210 | * @val: Value passed unmodified to notifier function | |
211 | * @v: Pointer passed unmodified to notifier function | |
212 | * | |
213 | * Calls each function in a notifier chain in turn. The functions | |
214 | * run in an atomic context, so they must not block. | |
215 | * This routine uses RCU to synchronize with changes to the chain. | |
216 | * | |
217 | * If the return value of the notifier can be and'ed | |
218 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain | |
219 | * will return immediately, with the return value of | |
220 | * the notifier function which halted execution. | |
221 | * Otherwise the return value is the return value | |
222 | * of the last notifier function called. | |
223 | */ | |
1da177e4 | 224 | |
f2aa85a0 | 225 | int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
e041c683 | 226 | unsigned long val, void *v) |
1da177e4 | 227 | { |
e041c683 AS |
228 | int ret; |
229 | ||
230 | rcu_read_lock(); | |
231 | ret = notifier_call_chain(&nh->head, val, v); | |
232 | rcu_read_unlock(); | |
233 | return ret; | |
1da177e4 LT |
234 | } |
235 | ||
e041c683 AS |
236 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); |
237 | ||
238 | /* | |
239 | * Blocking notifier chain routines. All access to the chain is | |
240 | * synchronized by an rwsem. | |
241 | */ | |
1da177e4 LT |
242 | |
243 | /** | |
e041c683 AS |
244 | * blocking_notifier_chain_register - Add notifier to a blocking notifier chain |
245 | * @nh: Pointer to head of the blocking notifier chain | |
1da177e4 LT |
246 | * @n: New entry in notifier chain |
247 | * | |
e041c683 AS |
248 | * Adds a notifier to a blocking notifier chain. |
249 | * Must be called in process context. | |
1da177e4 | 250 | * |
e041c683 | 251 | * Currently always returns zero. |
1da177e4 LT |
252 | */ |
253 | ||
e041c683 AS |
254 | int blocking_notifier_chain_register(struct blocking_notifier_head *nh, |
255 | struct notifier_block *n) | |
1da177e4 | 256 | { |
e041c683 AS |
257 | int ret; |
258 | ||
259 | /* | |
260 | * This code gets used during boot-up, when task switching is | |
261 | * not yet working and interrupts must remain disabled. At | |
262 | * such times we must not call down_write(). | |
263 | */ | |
264 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
265 | return notifier_chain_register(&nh->head, n); | |
266 | ||
267 | down_write(&nh->rwsem); | |
268 | ret = notifier_chain_register(&nh->head, n); | |
269 | up_write(&nh->rwsem); | |
270 | return ret; | |
1da177e4 LT |
271 | } |
272 | ||
e041c683 | 273 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); |
1da177e4 LT |
274 | |
275 | /** | |
e041c683 AS |
276 | * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain |
277 | * @nh: Pointer to head of the blocking notifier chain | |
278 | * @n: Entry to remove from notifier chain | |
279 | * | |
280 | * Removes a notifier from a blocking notifier chain. | |
281 | * Must be called from process context. | |
282 | * | |
283 | * Returns zero on success or %-ENOENT on failure. | |
284 | */ | |
285 | int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, | |
286 | struct notifier_block *n) | |
287 | { | |
288 | int ret; | |
289 | ||
290 | /* | |
291 | * This code gets used during boot-up, when task switching is | |
292 | * not yet working and interrupts must remain disabled. At | |
293 | * such times we must not call down_write(). | |
294 | */ | |
295 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
296 | return notifier_chain_unregister(&nh->head, n); | |
297 | ||
298 | down_write(&nh->rwsem); | |
299 | ret = notifier_chain_unregister(&nh->head, n); | |
300 | up_write(&nh->rwsem); | |
301 | return ret; | |
302 | } | |
303 | ||
304 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister); | |
305 | ||
306 | /** | |
307 | * blocking_notifier_call_chain - Call functions in a blocking notifier chain | |
308 | * @nh: Pointer to head of the blocking notifier chain | |
1da177e4 LT |
309 | * @val: Value passed unmodified to notifier function |
310 | * @v: Pointer passed unmodified to notifier function | |
311 | * | |
e041c683 AS |
312 | * Calls each function in a notifier chain in turn. The functions |
313 | * run in a process context, so they are allowed to block. | |
1da177e4 | 314 | * |
e041c683 AS |
315 | * If the return value of the notifier can be and'ed |
316 | * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain | |
1da177e4 LT |
317 | * will return immediately, with the return value of |
318 | * the notifier function which halted execution. | |
e041c683 | 319 | * Otherwise the return value is the return value |
1da177e4 LT |
320 | * of the last notifier function called. |
321 | */ | |
322 | ||
e041c683 AS |
323 | int blocking_notifier_call_chain(struct blocking_notifier_head *nh, |
324 | unsigned long val, void *v) | |
1da177e4 | 325 | { |
e041c683 AS |
326 | int ret; |
327 | ||
328 | down_read(&nh->rwsem); | |
329 | ret = notifier_call_chain(&nh->head, val, v); | |
330 | up_read(&nh->rwsem); | |
1da177e4 LT |
331 | return ret; |
332 | } | |
333 | ||
e041c683 AS |
334 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); |
335 | ||
336 | /* | |
337 | * Raw notifier chain routines. There is no protection; | |
338 | * the caller must provide it. Use at your own risk! | |
339 | */ | |
340 | ||
341 | /** | |
342 | * raw_notifier_chain_register - Add notifier to a raw notifier chain | |
343 | * @nh: Pointer to head of the raw notifier chain | |
344 | * @n: New entry in notifier chain | |
345 | * | |
346 | * Adds a notifier to a raw notifier chain. | |
347 | * All locking must be provided by the caller. | |
348 | * | |
349 | * Currently always returns zero. | |
350 | */ | |
351 | ||
352 | int raw_notifier_chain_register(struct raw_notifier_head *nh, | |
353 | struct notifier_block *n) | |
354 | { | |
355 | return notifier_chain_register(&nh->head, n); | |
356 | } | |
357 | ||
358 | EXPORT_SYMBOL_GPL(raw_notifier_chain_register); | |
359 | ||
360 | /** | |
361 | * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain | |
362 | * @nh: Pointer to head of the raw notifier chain | |
363 | * @n: Entry to remove from notifier chain | |
364 | * | |
365 | * Removes a notifier from a raw notifier chain. | |
366 | * All locking must be provided by the caller. | |
367 | * | |
368 | * Returns zero on success or %-ENOENT on failure. | |
369 | */ | |
370 | int raw_notifier_chain_unregister(struct raw_notifier_head *nh, | |
371 | struct notifier_block *n) | |
372 | { | |
373 | return notifier_chain_unregister(&nh->head, n); | |
374 | } | |
375 | ||
376 | EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister); | |
377 | ||
378 | /** | |
379 | * raw_notifier_call_chain - Call functions in a raw notifier chain | |
380 | * @nh: Pointer to head of the raw notifier chain | |
381 | * @val: Value passed unmodified to notifier function | |
382 | * @v: Pointer passed unmodified to notifier function | |
383 | * | |
384 | * Calls each function in a notifier chain in turn. The functions | |
385 | * run in an undefined context. | |
386 | * All locking must be provided by the caller. | |
387 | * | |
388 | * If the return value of the notifier can be and'ed | |
389 | * with %NOTIFY_STOP_MASK then raw_notifier_call_chain | |
390 | * will return immediately, with the return value of | |
391 | * the notifier function which halted execution. | |
392 | * Otherwise the return value is the return value | |
393 | * of the last notifier function called. | |
394 | */ | |
395 | ||
396 | int raw_notifier_call_chain(struct raw_notifier_head *nh, | |
397 | unsigned long val, void *v) | |
398 | { | |
399 | return notifier_call_chain(&nh->head, val, v); | |
400 | } | |
401 | ||
402 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain); | |
1da177e4 | 403 | |
eabc0694 AS |
404 | /* |
405 | * SRCU notifier chain routines. Registration and unregistration | |
406 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
407 | */ | |
408 | ||
409 | /** | |
410 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
411 | * @nh: Pointer to head of the SRCU notifier chain | |
412 | * @n: New entry in notifier chain | |
413 | * | |
414 | * Adds a notifier to an SRCU notifier chain. | |
415 | * Must be called in process context. | |
416 | * | |
417 | * Currently always returns zero. | |
418 | */ | |
419 | ||
420 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
421 | struct notifier_block *n) | |
422 | { | |
423 | int ret; | |
424 | ||
425 | /* | |
426 | * This code gets used during boot-up, when task switching is | |
427 | * not yet working and interrupts must remain disabled. At | |
428 | * such times we must not call mutex_lock(). | |
429 | */ | |
430 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
431 | return notifier_chain_register(&nh->head, n); | |
432 | ||
433 | mutex_lock(&nh->mutex); | |
434 | ret = notifier_chain_register(&nh->head, n); | |
435 | mutex_unlock(&nh->mutex); | |
436 | return ret; | |
437 | } | |
438 | ||
439 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
440 | ||
441 | /** | |
442 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
443 | * @nh: Pointer to head of the SRCU notifier chain | |
444 | * @n: Entry to remove from notifier chain | |
445 | * | |
446 | * Removes a notifier from an SRCU notifier chain. | |
447 | * Must be called from process context. | |
448 | * | |
449 | * Returns zero on success or %-ENOENT on failure. | |
450 | */ | |
451 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
452 | struct notifier_block *n) | |
453 | { | |
454 | int ret; | |
455 | ||
456 | /* | |
457 | * This code gets used during boot-up, when task switching is | |
458 | * not yet working and interrupts must remain disabled. At | |
459 | * such times we must not call mutex_lock(). | |
460 | */ | |
461 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
462 | return notifier_chain_unregister(&nh->head, n); | |
463 | ||
464 | mutex_lock(&nh->mutex); | |
465 | ret = notifier_chain_unregister(&nh->head, n); | |
466 | mutex_unlock(&nh->mutex); | |
467 | synchronize_srcu(&nh->srcu); | |
468 | return ret; | |
469 | } | |
470 | ||
471 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
472 | ||
473 | /** | |
474 | * srcu_notifier_call_chain - Call functions in an SRCU notifier chain | |
475 | * @nh: Pointer to head of the SRCU notifier chain | |
476 | * @val: Value passed unmodified to notifier function | |
477 | * @v: Pointer passed unmodified to notifier function | |
478 | * | |
479 | * Calls each function in a notifier chain in turn. The functions | |
480 | * run in a process context, so they are allowed to block. | |
481 | * | |
482 | * If the return value of the notifier can be and'ed | |
483 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain | |
484 | * will return immediately, with the return value of | |
485 | * the notifier function which halted execution. | |
486 | * Otherwise the return value is the return value | |
487 | * of the last notifier function called. | |
488 | */ | |
489 | ||
490 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, | |
491 | unsigned long val, void *v) | |
492 | { | |
493 | int ret; | |
494 | int idx; | |
495 | ||
496 | idx = srcu_read_lock(&nh->srcu); | |
497 | ret = notifier_call_chain(&nh->head, val, v); | |
498 | srcu_read_unlock(&nh->srcu, idx); | |
499 | return ret; | |
500 | } | |
501 | ||
502 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); | |
503 | ||
504 | /** | |
505 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
506 | * @nh: Pointer to head of the srcu notifier chain | |
507 | * | |
508 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
509 | * dynamic initialization. Be sure to call this routine before | |
510 | * calling any of the other SRCU notifier routines for this head. | |
511 | * | |
512 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
513 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
514 | * per-cpu data (used by the SRCU mechanism) will leak. | |
515 | */ | |
516 | ||
517 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
518 | { | |
519 | mutex_init(&nh->mutex); | |
e6a92013 AS |
520 | if (init_srcu_struct(&nh->srcu) < 0) |
521 | BUG(); | |
eabc0694 AS |
522 | nh->head = NULL; |
523 | } | |
524 | ||
525 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
526 | ||
1da177e4 LT |
527 | /** |
528 | * register_reboot_notifier - Register function to be called at reboot time | |
529 | * @nb: Info about notifier function to be called | |
530 | * | |
531 | * Registers a function with the list of functions | |
532 | * to be called at reboot time. | |
533 | * | |
e041c683 | 534 | * Currently always returns zero, as blocking_notifier_chain_register |
1da177e4 LT |
535 | * always returns zero. |
536 | */ | |
537 | ||
538 | int register_reboot_notifier(struct notifier_block * nb) | |
539 | { | |
e041c683 | 540 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); |
1da177e4 LT |
541 | } |
542 | ||
543 | EXPORT_SYMBOL(register_reboot_notifier); | |
544 | ||
545 | /** | |
546 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
547 | * @nb: Hook to be unregistered | |
548 | * | |
549 | * Unregisters a previously registered reboot | |
550 | * notifier function. | |
551 | * | |
552 | * Returns zero on success, or %-ENOENT on failure. | |
553 | */ | |
554 | ||
555 | int unregister_reboot_notifier(struct notifier_block * nb) | |
556 | { | |
e041c683 | 557 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); |
1da177e4 LT |
558 | } |
559 | ||
560 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
561 | ||
562 | static int set_one_prio(struct task_struct *p, int niceval, int error) | |
563 | { | |
564 | int no_nice; | |
565 | ||
566 | if (p->uid != current->euid && | |
567 | p->euid != current->euid && !capable(CAP_SYS_NICE)) { | |
568 | error = -EPERM; | |
569 | goto out; | |
570 | } | |
e43379f1 | 571 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
1da177e4 LT |
572 | error = -EACCES; |
573 | goto out; | |
574 | } | |
575 | no_nice = security_task_setnice(p, niceval); | |
576 | if (no_nice) { | |
577 | error = no_nice; | |
578 | goto out; | |
579 | } | |
580 | if (error == -ESRCH) | |
581 | error = 0; | |
582 | set_user_nice(p, niceval); | |
583 | out: | |
584 | return error; | |
585 | } | |
586 | ||
587 | asmlinkage long sys_setpriority(int which, int who, int niceval) | |
588 | { | |
589 | struct task_struct *g, *p; | |
590 | struct user_struct *user; | |
591 | int error = -EINVAL; | |
592 | ||
593 | if (which > 2 || which < 0) | |
594 | goto out; | |
595 | ||
596 | /* normalize: avoid signed division (rounding problems) */ | |
597 | error = -ESRCH; | |
598 | if (niceval < -20) | |
599 | niceval = -20; | |
600 | if (niceval > 19) | |
601 | niceval = 19; | |
602 | ||
603 | read_lock(&tasklist_lock); | |
604 | switch (which) { | |
605 | case PRIO_PROCESS: | |
606 | if (!who) | |
607 | who = current->pid; | |
608 | p = find_task_by_pid(who); | |
609 | if (p) | |
610 | error = set_one_prio(p, niceval, error); | |
611 | break; | |
612 | case PRIO_PGRP: | |
613 | if (!who) | |
614 | who = process_group(current); | |
615 | do_each_task_pid(who, PIDTYPE_PGID, p) { | |
616 | error = set_one_prio(p, niceval, error); | |
617 | } while_each_task_pid(who, PIDTYPE_PGID, p); | |
618 | break; | |
619 | case PRIO_USER: | |
620 | user = current->user; | |
621 | if (!who) | |
622 | who = current->uid; | |
623 | else | |
624 | if ((who != current->uid) && !(user = find_user(who))) | |
625 | goto out_unlock; /* No processes for this user */ | |
626 | ||
627 | do_each_thread(g, p) | |
628 | if (p->uid == who) | |
629 | error = set_one_prio(p, niceval, error); | |
630 | while_each_thread(g, p); | |
631 | if (who != current->uid) | |
632 | free_uid(user); /* For find_user() */ | |
633 | break; | |
634 | } | |
635 | out_unlock: | |
636 | read_unlock(&tasklist_lock); | |
637 | out: | |
638 | return error; | |
639 | } | |
640 | ||
641 | /* | |
642 | * Ugh. To avoid negative return values, "getpriority()" will | |
643 | * not return the normal nice-value, but a negated value that | |
644 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | |
645 | * to stay compatible. | |
646 | */ | |
647 | asmlinkage long sys_getpriority(int which, int who) | |
648 | { | |
649 | struct task_struct *g, *p; | |
650 | struct user_struct *user; | |
651 | long niceval, retval = -ESRCH; | |
652 | ||
653 | if (which > 2 || which < 0) | |
654 | return -EINVAL; | |
655 | ||
656 | read_lock(&tasklist_lock); | |
657 | switch (which) { | |
658 | case PRIO_PROCESS: | |
659 | if (!who) | |
660 | who = current->pid; | |
661 | p = find_task_by_pid(who); | |
662 | if (p) { | |
663 | niceval = 20 - task_nice(p); | |
664 | if (niceval > retval) | |
665 | retval = niceval; | |
666 | } | |
667 | break; | |
668 | case PRIO_PGRP: | |
669 | if (!who) | |
670 | who = process_group(current); | |
671 | do_each_task_pid(who, PIDTYPE_PGID, p) { | |
672 | niceval = 20 - task_nice(p); | |
673 | if (niceval > retval) | |
674 | retval = niceval; | |
675 | } while_each_task_pid(who, PIDTYPE_PGID, p); | |
676 | break; | |
677 | case PRIO_USER: | |
678 | user = current->user; | |
679 | if (!who) | |
680 | who = current->uid; | |
681 | else | |
682 | if ((who != current->uid) && !(user = find_user(who))) | |
683 | goto out_unlock; /* No processes for this user */ | |
684 | ||
685 | do_each_thread(g, p) | |
686 | if (p->uid == who) { | |
687 | niceval = 20 - task_nice(p); | |
688 | if (niceval > retval) | |
689 | retval = niceval; | |
690 | } | |
691 | while_each_thread(g, p); | |
692 | if (who != current->uid) | |
693 | free_uid(user); /* for find_user() */ | |
694 | break; | |
695 | } | |
696 | out_unlock: | |
697 | read_unlock(&tasklist_lock); | |
698 | ||
699 | return retval; | |
700 | } | |
701 | ||
e4c94330 EB |
702 | /** |
703 | * emergency_restart - reboot the system | |
704 | * | |
705 | * Without shutting down any hardware or taking any locks | |
706 | * reboot the system. This is called when we know we are in | |
707 | * trouble so this is our best effort to reboot. This is | |
708 | * safe to call in interrupt context. | |
709 | */ | |
7c903473 EB |
710 | void emergency_restart(void) |
711 | { | |
712 | machine_emergency_restart(); | |
713 | } | |
714 | EXPORT_SYMBOL_GPL(emergency_restart); | |
715 | ||
83cc5ed3 | 716 | static void kernel_restart_prepare(char *cmd) |
4a00ea1e | 717 | { |
e041c683 | 718 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
4a00ea1e | 719 | system_state = SYSTEM_RESTART; |
4a00ea1e | 720 | device_shutdown(); |
e4c94330 | 721 | } |
1e5d5331 RD |
722 | |
723 | /** | |
724 | * kernel_restart - reboot the system | |
725 | * @cmd: pointer to buffer containing command to execute for restart | |
b8887e6e | 726 | * or %NULL |
1e5d5331 RD |
727 | * |
728 | * Shutdown everything and perform a clean reboot. | |
729 | * This is not safe to call in interrupt context. | |
730 | */ | |
e4c94330 EB |
731 | void kernel_restart(char *cmd) |
732 | { | |
733 | kernel_restart_prepare(cmd); | |
756184b7 | 734 | if (!cmd) |
4a00ea1e | 735 | printk(KERN_EMERG "Restarting system.\n"); |
756184b7 | 736 | else |
4a00ea1e | 737 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
4a00ea1e EB |
738 | machine_restart(cmd); |
739 | } | |
740 | EXPORT_SYMBOL_GPL(kernel_restart); | |
741 | ||
e4c94330 EB |
742 | /** |
743 | * kernel_kexec - reboot the system | |
744 | * | |
745 | * Move into place and start executing a preloaded standalone | |
746 | * executable. If nothing was preloaded return an error. | |
747 | */ | |
83cc5ed3 | 748 | static void kernel_kexec(void) |
4a00ea1e EB |
749 | { |
750 | #ifdef CONFIG_KEXEC | |
751 | struct kimage *image; | |
4bb8089c | 752 | image = xchg(&kexec_image, NULL); |
756184b7 | 753 | if (!image) |
4a00ea1e | 754 | return; |
e4c94330 | 755 | kernel_restart_prepare(NULL); |
4a00ea1e EB |
756 | printk(KERN_EMERG "Starting new kernel\n"); |
757 | machine_shutdown(); | |
758 | machine_kexec(image); | |
759 | #endif | |
760 | } | |
4a00ea1e | 761 | |
729b4d4c AS |
762 | void kernel_shutdown_prepare(enum system_states state) |
763 | { | |
e041c683 | 764 | blocking_notifier_call_chain(&reboot_notifier_list, |
729b4d4c AS |
765 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
766 | system_state = state; | |
767 | device_shutdown(); | |
768 | } | |
e4c94330 EB |
769 | /** |
770 | * kernel_halt - halt the system | |
771 | * | |
772 | * Shutdown everything and perform a clean system halt. | |
773 | */ | |
e4c94330 EB |
774 | void kernel_halt(void) |
775 | { | |
729b4d4c | 776 | kernel_shutdown_prepare(SYSTEM_HALT); |
4a00ea1e EB |
777 | printk(KERN_EMERG "System halted.\n"); |
778 | machine_halt(); | |
779 | } | |
729b4d4c | 780 | |
4a00ea1e EB |
781 | EXPORT_SYMBOL_GPL(kernel_halt); |
782 | ||
e4c94330 EB |
783 | /** |
784 | * kernel_power_off - power_off the system | |
785 | * | |
786 | * Shutdown everything and perform a clean system power_off. | |
787 | */ | |
e4c94330 EB |
788 | void kernel_power_off(void) |
789 | { | |
729b4d4c | 790 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
4a00ea1e EB |
791 | printk(KERN_EMERG "Power down.\n"); |
792 | machine_power_off(); | |
793 | } | |
794 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
1da177e4 LT |
795 | /* |
796 | * Reboot system call: for obvious reasons only root may call it, | |
797 | * and even root needs to set up some magic numbers in the registers | |
798 | * so that some mistake won't make this reboot the whole machine. | |
799 | * You can also set the meaning of the ctrl-alt-del-key here. | |
800 | * | |
801 | * reboot doesn't sync: do that yourself before calling this. | |
802 | */ | |
803 | asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg) | |
804 | { | |
805 | char buffer[256]; | |
806 | ||
807 | /* We only trust the superuser with rebooting the system. */ | |
808 | if (!capable(CAP_SYS_BOOT)) | |
809 | return -EPERM; | |
810 | ||
811 | /* For safety, we require "magic" arguments. */ | |
812 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
813 | (magic2 != LINUX_REBOOT_MAGIC2 && | |
814 | magic2 != LINUX_REBOOT_MAGIC2A && | |
815 | magic2 != LINUX_REBOOT_MAGIC2B && | |
816 | magic2 != LINUX_REBOOT_MAGIC2C)) | |
817 | return -EINVAL; | |
818 | ||
5e38291d EB |
819 | /* Instead of trying to make the power_off code look like |
820 | * halt when pm_power_off is not set do it the easy way. | |
821 | */ | |
822 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) | |
823 | cmd = LINUX_REBOOT_CMD_HALT; | |
824 | ||
1da177e4 LT |
825 | lock_kernel(); |
826 | switch (cmd) { | |
827 | case LINUX_REBOOT_CMD_RESTART: | |
4a00ea1e | 828 | kernel_restart(NULL); |
1da177e4 LT |
829 | break; |
830 | ||
831 | case LINUX_REBOOT_CMD_CAD_ON: | |
832 | C_A_D = 1; | |
833 | break; | |
834 | ||
835 | case LINUX_REBOOT_CMD_CAD_OFF: | |
836 | C_A_D = 0; | |
837 | break; | |
838 | ||
839 | case LINUX_REBOOT_CMD_HALT: | |
4a00ea1e | 840 | kernel_halt(); |
1da177e4 LT |
841 | unlock_kernel(); |
842 | do_exit(0); | |
843 | break; | |
844 | ||
845 | case LINUX_REBOOT_CMD_POWER_OFF: | |
4a00ea1e | 846 | kernel_power_off(); |
1da177e4 LT |
847 | unlock_kernel(); |
848 | do_exit(0); | |
849 | break; | |
850 | ||
851 | case LINUX_REBOOT_CMD_RESTART2: | |
852 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | |
853 | unlock_kernel(); | |
854 | return -EFAULT; | |
855 | } | |
856 | buffer[sizeof(buffer) - 1] = '\0'; | |
857 | ||
4a00ea1e | 858 | kernel_restart(buffer); |
1da177e4 LT |
859 | break; |
860 | ||
dc009d92 | 861 | case LINUX_REBOOT_CMD_KEXEC: |
4a00ea1e EB |
862 | kernel_kexec(); |
863 | unlock_kernel(); | |
864 | return -EINVAL; | |
865 | ||
1da177e4 LT |
866 | #ifdef CONFIG_SOFTWARE_SUSPEND |
867 | case LINUX_REBOOT_CMD_SW_SUSPEND: | |
868 | { | |
869 | int ret = software_suspend(); | |
870 | unlock_kernel(); | |
871 | return ret; | |
872 | } | |
873 | #endif | |
874 | ||
875 | default: | |
876 | unlock_kernel(); | |
877 | return -EINVAL; | |
878 | } | |
879 | unlock_kernel(); | |
880 | return 0; | |
881 | } | |
882 | ||
65f27f38 | 883 | static void deferred_cad(struct work_struct *dummy) |
1da177e4 | 884 | { |
abcd9e51 | 885 | kernel_restart(NULL); |
1da177e4 LT |
886 | } |
887 | ||
888 | /* | |
889 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
890 | * As it's called within an interrupt, it may NOT sync: the only choice | |
891 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
892 | */ | |
893 | void ctrl_alt_del(void) | |
894 | { | |
65f27f38 | 895 | static DECLARE_WORK(cad_work, deferred_cad); |
1da177e4 LT |
896 | |
897 | if (C_A_D) | |
898 | schedule_work(&cad_work); | |
899 | else | |
9ec52099 | 900 | kill_cad_pid(SIGINT, 1); |
1da177e4 LT |
901 | } |
902 | ||
1da177e4 LT |
903 | /* |
904 | * Unprivileged users may change the real gid to the effective gid | |
905 | * or vice versa. (BSD-style) | |
906 | * | |
907 | * If you set the real gid at all, or set the effective gid to a value not | |
908 | * equal to the real gid, then the saved gid is set to the new effective gid. | |
909 | * | |
910 | * This makes it possible for a setgid program to completely drop its | |
911 | * privileges, which is often a useful assertion to make when you are doing | |
912 | * a security audit over a program. | |
913 | * | |
914 | * The general idea is that a program which uses just setregid() will be | |
915 | * 100% compatible with BSD. A program which uses just setgid() will be | |
916 | * 100% compatible with POSIX with saved IDs. | |
917 | * | |
918 | * SMP: There are not races, the GIDs are checked only by filesystem | |
919 | * operations (as far as semantic preservation is concerned). | |
920 | */ | |
921 | asmlinkage long sys_setregid(gid_t rgid, gid_t egid) | |
922 | { | |
923 | int old_rgid = current->gid; | |
924 | int old_egid = current->egid; | |
925 | int new_rgid = old_rgid; | |
926 | int new_egid = old_egid; | |
927 | int retval; | |
928 | ||
929 | retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); | |
930 | if (retval) | |
931 | return retval; | |
932 | ||
933 | if (rgid != (gid_t) -1) { | |
934 | if ((old_rgid == rgid) || | |
935 | (current->egid==rgid) || | |
936 | capable(CAP_SETGID)) | |
937 | new_rgid = rgid; | |
938 | else | |
939 | return -EPERM; | |
940 | } | |
941 | if (egid != (gid_t) -1) { | |
942 | if ((old_rgid == egid) || | |
943 | (current->egid == egid) || | |
944 | (current->sgid == egid) || | |
945 | capable(CAP_SETGID)) | |
946 | new_egid = egid; | |
756184b7 | 947 | else |
1da177e4 | 948 | return -EPERM; |
1da177e4 | 949 | } |
756184b7 | 950 | if (new_egid != old_egid) { |
d6e71144 | 951 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 952 | smp_wmb(); |
1da177e4 LT |
953 | } |
954 | if (rgid != (gid_t) -1 || | |
955 | (egid != (gid_t) -1 && egid != old_rgid)) | |
956 | current->sgid = new_egid; | |
957 | current->fsgid = new_egid; | |
958 | current->egid = new_egid; | |
959 | current->gid = new_rgid; | |
960 | key_fsgid_changed(current); | |
9f46080c | 961 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
962 | return 0; |
963 | } | |
964 | ||
965 | /* | |
966 | * setgid() is implemented like SysV w/ SAVED_IDS | |
967 | * | |
968 | * SMP: Same implicit races as above. | |
969 | */ | |
970 | asmlinkage long sys_setgid(gid_t gid) | |
971 | { | |
972 | int old_egid = current->egid; | |
973 | int retval; | |
974 | ||
975 | retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); | |
976 | if (retval) | |
977 | return retval; | |
978 | ||
756184b7 CP |
979 | if (capable(CAP_SETGID)) { |
980 | if (old_egid != gid) { | |
d6e71144 | 981 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 982 | smp_wmb(); |
1da177e4 LT |
983 | } |
984 | current->gid = current->egid = current->sgid = current->fsgid = gid; | |
756184b7 CP |
985 | } else if ((gid == current->gid) || (gid == current->sgid)) { |
986 | if (old_egid != gid) { | |
d6e71144 | 987 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 988 | smp_wmb(); |
1da177e4 LT |
989 | } |
990 | current->egid = current->fsgid = gid; | |
991 | } | |
992 | else | |
993 | return -EPERM; | |
994 | ||
995 | key_fsgid_changed(current); | |
9f46080c | 996 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
997 | return 0; |
998 | } | |
999 | ||
1000 | static int set_user(uid_t new_ruid, int dumpclear) | |
1001 | { | |
1002 | struct user_struct *new_user; | |
1003 | ||
1004 | new_user = alloc_uid(new_ruid); | |
1005 | if (!new_user) | |
1006 | return -EAGAIN; | |
1007 | ||
1008 | if (atomic_read(&new_user->processes) >= | |
1009 | current->signal->rlim[RLIMIT_NPROC].rlim_cur && | |
1010 | new_user != &root_user) { | |
1011 | free_uid(new_user); | |
1012 | return -EAGAIN; | |
1013 | } | |
1014 | ||
1015 | switch_uid(new_user); | |
1016 | ||
756184b7 | 1017 | if (dumpclear) { |
d6e71144 | 1018 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1019 | smp_wmb(); |
1da177e4 LT |
1020 | } |
1021 | current->uid = new_ruid; | |
1022 | return 0; | |
1023 | } | |
1024 | ||
1025 | /* | |
1026 | * Unprivileged users may change the real uid to the effective uid | |
1027 | * or vice versa. (BSD-style) | |
1028 | * | |
1029 | * If you set the real uid at all, or set the effective uid to a value not | |
1030 | * equal to the real uid, then the saved uid is set to the new effective uid. | |
1031 | * | |
1032 | * This makes it possible for a setuid program to completely drop its | |
1033 | * privileges, which is often a useful assertion to make when you are doing | |
1034 | * a security audit over a program. | |
1035 | * | |
1036 | * The general idea is that a program which uses just setreuid() will be | |
1037 | * 100% compatible with BSD. A program which uses just setuid() will be | |
1038 | * 100% compatible with POSIX with saved IDs. | |
1039 | */ | |
1040 | asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) | |
1041 | { | |
1042 | int old_ruid, old_euid, old_suid, new_ruid, new_euid; | |
1043 | int retval; | |
1044 | ||
1045 | retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); | |
1046 | if (retval) | |
1047 | return retval; | |
1048 | ||
1049 | new_ruid = old_ruid = current->uid; | |
1050 | new_euid = old_euid = current->euid; | |
1051 | old_suid = current->suid; | |
1052 | ||
1053 | if (ruid != (uid_t) -1) { | |
1054 | new_ruid = ruid; | |
1055 | if ((old_ruid != ruid) && | |
1056 | (current->euid != ruid) && | |
1057 | !capable(CAP_SETUID)) | |
1058 | return -EPERM; | |
1059 | } | |
1060 | ||
1061 | if (euid != (uid_t) -1) { | |
1062 | new_euid = euid; | |
1063 | if ((old_ruid != euid) && | |
1064 | (current->euid != euid) && | |
1065 | (current->suid != euid) && | |
1066 | !capable(CAP_SETUID)) | |
1067 | return -EPERM; | |
1068 | } | |
1069 | ||
1070 | if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0) | |
1071 | return -EAGAIN; | |
1072 | ||
756184b7 | 1073 | if (new_euid != old_euid) { |
d6e71144 | 1074 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1075 | smp_wmb(); |
1da177e4 LT |
1076 | } |
1077 | current->fsuid = current->euid = new_euid; | |
1078 | if (ruid != (uid_t) -1 || | |
1079 | (euid != (uid_t) -1 && euid != old_ruid)) | |
1080 | current->suid = current->euid; | |
1081 | current->fsuid = current->euid; | |
1082 | ||
1083 | key_fsuid_changed(current); | |
9f46080c | 1084 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1085 | |
1086 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE); | |
1087 | } | |
1088 | ||
1089 | ||
1090 | ||
1091 | /* | |
1092 | * setuid() is implemented like SysV with SAVED_IDS | |
1093 | * | |
1094 | * Note that SAVED_ID's is deficient in that a setuid root program | |
1095 | * like sendmail, for example, cannot set its uid to be a normal | |
1096 | * user and then switch back, because if you're root, setuid() sets | |
1097 | * the saved uid too. If you don't like this, blame the bright people | |
1098 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | |
1099 | * will allow a root program to temporarily drop privileges and be able to | |
1100 | * regain them by swapping the real and effective uid. | |
1101 | */ | |
1102 | asmlinkage long sys_setuid(uid_t uid) | |
1103 | { | |
1104 | int old_euid = current->euid; | |
a09c17a6 | 1105 | int old_ruid, old_suid, new_suid; |
1da177e4 LT |
1106 | int retval; |
1107 | ||
1108 | retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); | |
1109 | if (retval) | |
1110 | return retval; | |
1111 | ||
a09c17a6 | 1112 | old_ruid = current->uid; |
1da177e4 LT |
1113 | old_suid = current->suid; |
1114 | new_suid = old_suid; | |
1115 | ||
1116 | if (capable(CAP_SETUID)) { | |
1117 | if (uid != old_ruid && set_user(uid, old_euid != uid) < 0) | |
1118 | return -EAGAIN; | |
1119 | new_suid = uid; | |
1120 | } else if ((uid != current->uid) && (uid != new_suid)) | |
1121 | return -EPERM; | |
1122 | ||
756184b7 | 1123 | if (old_euid != uid) { |
d6e71144 | 1124 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1125 | smp_wmb(); |
1da177e4 LT |
1126 | } |
1127 | current->fsuid = current->euid = uid; | |
1128 | current->suid = new_suid; | |
1129 | ||
1130 | key_fsuid_changed(current); | |
9f46080c | 1131 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1132 | |
1133 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID); | |
1134 | } | |
1135 | ||
1136 | ||
1137 | /* | |
1138 | * This function implements a generic ability to update ruid, euid, | |
1139 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | |
1140 | */ | |
1141 | asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) | |
1142 | { | |
1143 | int old_ruid = current->uid; | |
1144 | int old_euid = current->euid; | |
1145 | int old_suid = current->suid; | |
1146 | int retval; | |
1147 | ||
1148 | retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); | |
1149 | if (retval) | |
1150 | return retval; | |
1151 | ||
1152 | if (!capable(CAP_SETUID)) { | |
1153 | if ((ruid != (uid_t) -1) && (ruid != current->uid) && | |
1154 | (ruid != current->euid) && (ruid != current->suid)) | |
1155 | return -EPERM; | |
1156 | if ((euid != (uid_t) -1) && (euid != current->uid) && | |
1157 | (euid != current->euid) && (euid != current->suid)) | |
1158 | return -EPERM; | |
1159 | if ((suid != (uid_t) -1) && (suid != current->uid) && | |
1160 | (suid != current->euid) && (suid != current->suid)) | |
1161 | return -EPERM; | |
1162 | } | |
1163 | if (ruid != (uid_t) -1) { | |
1164 | if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0) | |
1165 | return -EAGAIN; | |
1166 | } | |
1167 | if (euid != (uid_t) -1) { | |
756184b7 | 1168 | if (euid != current->euid) { |
d6e71144 | 1169 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1170 | smp_wmb(); |
1da177e4 LT |
1171 | } |
1172 | current->euid = euid; | |
1173 | } | |
1174 | current->fsuid = current->euid; | |
1175 | if (suid != (uid_t) -1) | |
1176 | current->suid = suid; | |
1177 | ||
1178 | key_fsuid_changed(current); | |
9f46080c | 1179 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1180 | |
1181 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); | |
1182 | } | |
1183 | ||
1184 | asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) | |
1185 | { | |
1186 | int retval; | |
1187 | ||
1188 | if (!(retval = put_user(current->uid, ruid)) && | |
1189 | !(retval = put_user(current->euid, euid))) | |
1190 | retval = put_user(current->suid, suid); | |
1191 | ||
1192 | return retval; | |
1193 | } | |
1194 | ||
1195 | /* | |
1196 | * Same as above, but for rgid, egid, sgid. | |
1197 | */ | |
1198 | asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) | |
1199 | { | |
1200 | int retval; | |
1201 | ||
1202 | retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); | |
1203 | if (retval) | |
1204 | return retval; | |
1205 | ||
1206 | if (!capable(CAP_SETGID)) { | |
1207 | if ((rgid != (gid_t) -1) && (rgid != current->gid) && | |
1208 | (rgid != current->egid) && (rgid != current->sgid)) | |
1209 | return -EPERM; | |
1210 | if ((egid != (gid_t) -1) && (egid != current->gid) && | |
1211 | (egid != current->egid) && (egid != current->sgid)) | |
1212 | return -EPERM; | |
1213 | if ((sgid != (gid_t) -1) && (sgid != current->gid) && | |
1214 | (sgid != current->egid) && (sgid != current->sgid)) | |
1215 | return -EPERM; | |
1216 | } | |
1217 | if (egid != (gid_t) -1) { | |
756184b7 | 1218 | if (egid != current->egid) { |
d6e71144 | 1219 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1220 | smp_wmb(); |
1da177e4 LT |
1221 | } |
1222 | current->egid = egid; | |
1223 | } | |
1224 | current->fsgid = current->egid; | |
1225 | if (rgid != (gid_t) -1) | |
1226 | current->gid = rgid; | |
1227 | if (sgid != (gid_t) -1) | |
1228 | current->sgid = sgid; | |
1229 | ||
1230 | key_fsgid_changed(current); | |
9f46080c | 1231 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1232 | return 0; |
1233 | } | |
1234 | ||
1235 | asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) | |
1236 | { | |
1237 | int retval; | |
1238 | ||
1239 | if (!(retval = put_user(current->gid, rgid)) && | |
1240 | !(retval = put_user(current->egid, egid))) | |
1241 | retval = put_user(current->sgid, sgid); | |
1242 | ||
1243 | return retval; | |
1244 | } | |
1245 | ||
1246 | ||
1247 | /* | |
1248 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | |
1249 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | |
1250 | * whatever uid it wants to). It normally shadows "euid", except when | |
1251 | * explicitly set by setfsuid() or for access.. | |
1252 | */ | |
1253 | asmlinkage long sys_setfsuid(uid_t uid) | |
1254 | { | |
1255 | int old_fsuid; | |
1256 | ||
1257 | old_fsuid = current->fsuid; | |
1258 | if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) | |
1259 | return old_fsuid; | |
1260 | ||
1261 | if (uid == current->uid || uid == current->euid || | |
1262 | uid == current->suid || uid == current->fsuid || | |
756184b7 CP |
1263 | capable(CAP_SETUID)) { |
1264 | if (uid != old_fsuid) { | |
d6e71144 | 1265 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1266 | smp_wmb(); |
1da177e4 LT |
1267 | } |
1268 | current->fsuid = uid; | |
1269 | } | |
1270 | ||
1271 | key_fsuid_changed(current); | |
9f46080c | 1272 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1273 | |
1274 | security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); | |
1275 | ||
1276 | return old_fsuid; | |
1277 | } | |
1278 | ||
1279 | /* | |
1280 |