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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 | ||
6f7cc11a GS |
137 | /** |
138 | * notifier_call_chain - Informs the registered notifiers about an event. | |
139 | * @nl: Pointer to head of the blocking notifier chain | |
140 | * @val: Value passed unmodified to notifier function | |
141 | * @v: Pointer passed unmodified to notifier function | |
142 | * @nr_to_call: Number of notifier functions to be called. Don't care | |
143 | * value of this parameter is -1. | |
144 | * @nr_calls: Records the number of notifications sent. Don't care | |
145 | * value of this field is NULL. | |
146 | * @returns: notifier_call_chain returns the value returned by the | |
147 | * last notifier function called. | |
148 | */ | |
149 | ||
e041c683 | 150 | static int __kprobes notifier_call_chain(struct notifier_block **nl, |
6f7cc11a GS |
151 | unsigned long val, void *v, |
152 | int nr_to_call, int *nr_calls) | |
e041c683 AS |
153 | { |
154 | int ret = NOTIFY_DONE; | |
bbb1747d | 155 | struct notifier_block *nb, *next_nb; |
e041c683 AS |
156 | |
157 | nb = rcu_dereference(*nl); | |
6f7cc11a GS |
158 | |
159 | while (nb && nr_to_call) { | |
bbb1747d | 160 | next_nb = rcu_dereference(nb->next); |
e041c683 | 161 | ret = nb->notifier_call(nb, val, v); |
6f7cc11a GS |
162 | |
163 | if (nr_calls) | |
164 | (*nr_calls)++; | |
165 | ||
e041c683 AS |
166 | if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK) |
167 | break; | |
bbb1747d | 168 | nb = next_nb; |
6f7cc11a | 169 | nr_to_call--; |
e041c683 AS |
170 | } |
171 | return ret; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Atomic notifier chain routines. Registration and unregistration | |
eabc0694 | 176 | * use a spinlock, and call_chain is synchronized by RCU (no locks). |
e041c683 | 177 | */ |
1da177e4 LT |
178 | |
179 | /** | |
e041c683 AS |
180 | * atomic_notifier_chain_register - Add notifier to an atomic notifier chain |
181 | * @nh: Pointer to head of the atomic notifier chain | |
1da177e4 LT |
182 | * @n: New entry in notifier chain |
183 | * | |
e041c683 | 184 | * Adds a notifier to an atomic notifier chain. |
1da177e4 LT |
185 | * |
186 | * Currently always returns zero. | |
187 | */ | |
e041c683 AS |
188 | |
189 | int atomic_notifier_chain_register(struct atomic_notifier_head *nh, | |
190 | struct notifier_block *n) | |
191 | { | |
192 | unsigned long flags; | |
193 | int ret; | |
194 | ||
195 | spin_lock_irqsave(&nh->lock, flags); | |
196 | ret = notifier_chain_register(&nh->head, n); | |
197 | spin_unlock_irqrestore(&nh->lock, flags); | |
198 | return ret; | |
199 | } | |
200 | ||
201 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_register); | |
202 | ||
203 | /** | |
204 | * atomic_notifier_chain_unregister - Remove notifier from an atomic notifier chain | |
205 | * @nh: Pointer to head of the atomic notifier chain | |
206 | * @n: Entry to remove from notifier chain | |
207 | * | |
208 | * Removes a notifier from an atomic notifier chain. | |
209 | * | |
210 | * Returns zero on success or %-ENOENT on failure. | |
211 | */ | |
212 | int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh, | |
213 | struct notifier_block *n) | |
214 | { | |
215 | unsigned long flags; | |
216 | int ret; | |
217 | ||
218 | spin_lock_irqsave(&nh->lock, flags); | |
219 | ret = notifier_chain_unregister(&nh->head, n); | |
220 | spin_unlock_irqrestore(&nh->lock, flags); | |
221 | synchronize_rcu(); | |
222 | return ret; | |
223 | } | |
224 | ||
225 | EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister); | |
226 | ||
227 | /** | |
6f7cc11a | 228 | * __atomic_notifier_call_chain - Call functions in an atomic notifier chain |
e041c683 AS |
229 | * @nh: Pointer to head of the atomic notifier chain |
230 | * @val: Value passed unmodified to notifier function | |
231 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
232 | * @nr_to_call: See the comment for notifier_call_chain. |
233 | * @nr_calls: See the comment for notifier_call_chain. | |
e041c683 AS |
234 | * |
235 | * Calls each function in a notifier chain in turn. The functions | |
236 | * run in an atomic context, so they must not block. | |
237 | * This routine uses RCU to synchronize with changes to the chain. | |
238 | * | |
239 | * If the return value of the notifier can be and'ed | |
72fd4a35 | 240 | * with %NOTIFY_STOP_MASK then atomic_notifier_call_chain() |
e041c683 AS |
241 | * will return immediately, with the return value of |
242 | * the notifier function which halted execution. | |
243 | * Otherwise the return value is the return value | |
244 | * of the last notifier function called. | |
245 | */ | |
1da177e4 | 246 | |
6f7cc11a GS |
247 | int __kprobes __atomic_notifier_call_chain(struct atomic_notifier_head *nh, |
248 | unsigned long val, void *v, | |
249 | int nr_to_call, int *nr_calls) | |
1da177e4 | 250 | { |
e041c683 AS |
251 | int ret; |
252 | ||
253 | rcu_read_lock(); | |
6f7cc11a | 254 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); |
e041c683 AS |
255 | rcu_read_unlock(); |
256 | return ret; | |
1da177e4 LT |
257 | } |
258 | ||
6f7cc11a GS |
259 | EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain); |
260 | ||
261 | int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh, | |
262 | unsigned long val, void *v) | |
263 | { | |
264 | return __atomic_notifier_call_chain(nh, val, v, -1, NULL); | |
265 | } | |
e041c683 | 266 | |
6f7cc11a | 267 | EXPORT_SYMBOL_GPL(atomic_notifier_call_chain); |
e041c683 AS |
268 | /* |
269 | * Blocking notifier chain routines. All access to the chain is | |
270 | * synchronized by an rwsem. | |
271 | */ | |
1da177e4 LT |
272 | |
273 | /** | |
e041c683 AS |
274 | * blocking_notifier_chain_register - Add notifier to a blocking notifier chain |
275 | * @nh: Pointer to head of the blocking notifier chain | |
1da177e4 LT |
276 | * @n: New entry in notifier chain |
277 | * | |
e041c683 AS |
278 | * Adds a notifier to a blocking notifier chain. |
279 | * Must be called in process context. | |
1da177e4 | 280 | * |
e041c683 | 281 | * Currently always returns zero. |
1da177e4 LT |
282 | */ |
283 | ||
e041c683 AS |
284 | int blocking_notifier_chain_register(struct blocking_notifier_head *nh, |
285 | struct notifier_block *n) | |
1da177e4 | 286 | { |
e041c683 AS |
287 | int ret; |
288 | ||
289 | /* | |
290 | * This code gets used during boot-up, when task switching is | |
291 | * not yet working and interrupts must remain disabled. At | |
292 | * such times we must not call down_write(). | |
293 | */ | |
294 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
295 | return notifier_chain_register(&nh->head, n); | |
296 | ||
297 | down_write(&nh->rwsem); | |
298 | ret = notifier_chain_register(&nh->head, n); | |
299 | up_write(&nh->rwsem); | |
300 | return ret; | |
1da177e4 LT |
301 | } |
302 | ||
e041c683 | 303 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_register); |
1da177e4 LT |
304 | |
305 | /** | |
e041c683 AS |
306 | * blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain |
307 | * @nh: Pointer to head of the blocking notifier chain | |
308 | * @n: Entry to remove from notifier chain | |
309 | * | |
310 | * Removes a notifier from a blocking notifier chain. | |
311 | * Must be called from process context. | |
312 | * | |
313 | * Returns zero on success or %-ENOENT on failure. | |
314 | */ | |
315 | int blocking_notifier_chain_unregister(struct blocking_notifier_head *nh, | |
316 | struct notifier_block *n) | |
317 | { | |
318 | int ret; | |
319 | ||
320 | /* | |
321 | * This code gets used during boot-up, when task switching is | |
322 | * not yet working and interrupts must remain disabled. At | |
323 | * such times we must not call down_write(). | |
324 | */ | |
325 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
326 | return notifier_chain_unregister(&nh->head, n); | |
327 | ||
328 | down_write(&nh->rwsem); | |
329 | ret = notifier_chain_unregister(&nh->head, n); | |
330 | up_write(&nh->rwsem); | |
331 | return ret; | |
332 | } | |
333 | ||
334 | EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister); | |
335 | ||
336 | /** | |
6f7cc11a | 337 | * __blocking_notifier_call_chain - Call functions in a blocking notifier chain |
e041c683 | 338 | * @nh: Pointer to head of the blocking notifier chain |
1da177e4 LT |
339 | * @val: Value passed unmodified to notifier function |
340 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
341 | * @nr_to_call: See comment for notifier_call_chain. |
342 | * @nr_calls: See comment for notifier_call_chain. | |
1da177e4 | 343 | * |
e041c683 AS |
344 | * Calls each function in a notifier chain in turn. The functions |
345 | * run in a process context, so they are allowed to block. | |
1da177e4 | 346 | * |
e041c683 | 347 | * If the return value of the notifier can be and'ed |
72fd4a35 | 348 | * with %NOTIFY_STOP_MASK then blocking_notifier_call_chain() |
1da177e4 LT |
349 | * will return immediately, with the return value of |
350 | * the notifier function which halted execution. | |
e041c683 | 351 | * Otherwise the return value is the return value |
1da177e4 LT |
352 | * of the last notifier function called. |
353 | */ | |
354 | ||
6f7cc11a GS |
355 | int __blocking_notifier_call_chain(struct blocking_notifier_head *nh, |
356 | unsigned long val, void *v, | |
357 | int nr_to_call, int *nr_calls) | |
1da177e4 | 358 | { |
1b5180b6 | 359 | int ret = NOTIFY_DONE; |
e041c683 | 360 | |
1b5180b6 IM |
361 | /* |
362 | * We check the head outside the lock, but if this access is | |
363 | * racy then it does not matter what the result of the test | |
364 | * is, we re-check the list after having taken the lock anyway: | |
365 | */ | |
366 | if (rcu_dereference(nh->head)) { | |
367 | down_read(&nh->rwsem); | |
6f7cc11a GS |
368 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, |
369 | nr_calls); | |
1b5180b6 IM |
370 | up_read(&nh->rwsem); |
371 | } | |
1da177e4 LT |
372 | return ret; |
373 | } | |
6f7cc11a | 374 | EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain); |
1da177e4 | 375 | |
6f7cc11a GS |
376 | int blocking_notifier_call_chain(struct blocking_notifier_head *nh, |
377 | unsigned long val, void *v) | |
378 | { | |
379 | return __blocking_notifier_call_chain(nh, val, v, -1, NULL); | |
380 | } | |
e041c683 AS |
381 | EXPORT_SYMBOL_GPL(blocking_notifier_call_chain); |
382 | ||
383 | /* | |
384 | * Raw notifier chain routines. There is no protection; | |
385 | * the caller must provide it. Use at your own risk! | |
386 | */ | |
387 | ||
388 | /** | |
389 | * raw_notifier_chain_register - Add notifier to a raw notifier chain | |
390 | * @nh: Pointer to head of the raw notifier chain | |
391 | * @n: New entry in notifier chain | |
392 | * | |
393 | * Adds a notifier to a raw notifier chain. | |
394 | * All locking must be provided by the caller. | |
395 | * | |
396 | * Currently always returns zero. | |
397 | */ | |
398 | ||
399 | int raw_notifier_chain_register(struct raw_notifier_head *nh, | |
400 | struct notifier_block *n) | |
401 | { | |
402 | return notifier_chain_register(&nh->head, n); | |
403 | } | |
404 | ||
405 | EXPORT_SYMBOL_GPL(raw_notifier_chain_register); | |
406 | ||
407 | /** | |
408 | * raw_notifier_chain_unregister - Remove notifier from a raw notifier chain | |
409 | * @nh: Pointer to head of the raw notifier chain | |
410 | * @n: Entry to remove from notifier chain | |
411 | * | |
412 | * Removes a notifier from a raw notifier chain. | |
413 | * All locking must be provided by the caller. | |
414 | * | |
415 | * Returns zero on success or %-ENOENT on failure. | |
416 | */ | |
417 | int raw_notifier_chain_unregister(struct raw_notifier_head *nh, | |
418 | struct notifier_block *n) | |
419 | { | |
420 | return notifier_chain_unregister(&nh->head, n); | |
421 | } | |
422 | ||
423 | EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister); | |
424 | ||
425 | /** | |
6f7cc11a | 426 | * __raw_notifier_call_chain - Call functions in a raw notifier chain |
e041c683 AS |
427 | * @nh: Pointer to head of the raw notifier chain |
428 | * @val: Value passed unmodified to notifier function | |
429 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
430 | * @nr_to_call: See comment for notifier_call_chain. |
431 | * @nr_calls: See comment for notifier_call_chain | |
e041c683 AS |
432 | * |
433 | * Calls each function in a notifier chain in turn. The functions | |
434 | * run in an undefined context. | |
435 | * All locking must be provided by the caller. | |
436 | * | |
437 | * If the return value of the notifier can be and'ed | |
72fd4a35 | 438 | * with %NOTIFY_STOP_MASK then raw_notifier_call_chain() |
e041c683 AS |
439 | * will return immediately, with the return value of |
440 | * the notifier function which halted execution. | |
441 | * Otherwise the return value is the return value | |
442 | * of the last notifier function called. | |
443 | */ | |
444 | ||
6f7cc11a GS |
445 | int __raw_notifier_call_chain(struct raw_notifier_head *nh, |
446 | unsigned long val, void *v, | |
447 | int nr_to_call, int *nr_calls) | |
448 | { | |
449 | return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); | |
450 | } | |
451 | ||
452 | EXPORT_SYMBOL_GPL(__raw_notifier_call_chain); | |
453 | ||
e041c683 AS |
454 | int raw_notifier_call_chain(struct raw_notifier_head *nh, |
455 | unsigned long val, void *v) | |
456 | { | |
6f7cc11a | 457 | return __raw_notifier_call_chain(nh, val, v, -1, NULL); |
e041c683 AS |
458 | } |
459 | ||
460 | EXPORT_SYMBOL_GPL(raw_notifier_call_chain); | |
1da177e4 | 461 | |
eabc0694 AS |
462 | /* |
463 | * SRCU notifier chain routines. Registration and unregistration | |
464 | * use a mutex, and call_chain is synchronized by SRCU (no locks). | |
465 | */ | |
466 | ||
467 | /** | |
468 | * srcu_notifier_chain_register - Add notifier to an SRCU notifier chain | |
469 | * @nh: Pointer to head of the SRCU notifier chain | |
470 | * @n: New entry in notifier chain | |
471 | * | |
472 | * Adds a notifier to an SRCU notifier chain. | |
473 | * Must be called in process context. | |
474 | * | |
475 | * Currently always returns zero. | |
476 | */ | |
477 | ||
478 | int srcu_notifier_chain_register(struct srcu_notifier_head *nh, | |
479 | struct notifier_block *n) | |
480 | { | |
481 | int ret; | |
482 | ||
483 | /* | |
484 | * This code gets used during boot-up, when task switching is | |
485 | * not yet working and interrupts must remain disabled. At | |
486 | * such times we must not call mutex_lock(). | |
487 | */ | |
488 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
489 | return notifier_chain_register(&nh->head, n); | |
490 | ||
491 | mutex_lock(&nh->mutex); | |
492 | ret = notifier_chain_register(&nh->head, n); | |
493 | mutex_unlock(&nh->mutex); | |
494 | return ret; | |
495 | } | |
496 | ||
497 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_register); | |
498 | ||
499 | /** | |
500 | * srcu_notifier_chain_unregister - Remove notifier from an SRCU notifier chain | |
501 | * @nh: Pointer to head of the SRCU notifier chain | |
502 | * @n: Entry to remove from notifier chain | |
503 | * | |
504 | * Removes a notifier from an SRCU notifier chain. | |
505 | * Must be called from process context. | |
506 | * | |
507 | * Returns zero on success or %-ENOENT on failure. | |
508 | */ | |
509 | int srcu_notifier_chain_unregister(struct srcu_notifier_head *nh, | |
510 | struct notifier_block *n) | |
511 | { | |
512 | int ret; | |
513 | ||
514 | /* | |
515 | * This code gets used during boot-up, when task switching is | |
516 | * not yet working and interrupts must remain disabled. At | |
517 | * such times we must not call mutex_lock(). | |
518 | */ | |
519 | if (unlikely(system_state == SYSTEM_BOOTING)) | |
520 | return notifier_chain_unregister(&nh->head, n); | |
521 | ||
522 | mutex_lock(&nh->mutex); | |
523 | ret = notifier_chain_unregister(&nh->head, n); | |
524 | mutex_unlock(&nh->mutex); | |
525 | synchronize_srcu(&nh->srcu); | |
526 | return ret; | |
527 | } | |
528 | ||
529 | EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister); | |
530 | ||
531 | /** | |
6f7cc11a | 532 | * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain |
eabc0694 AS |
533 | * @nh: Pointer to head of the SRCU notifier chain |
534 | * @val: Value passed unmodified to notifier function | |
535 | * @v: Pointer passed unmodified to notifier function | |
6f7cc11a GS |
536 | * @nr_to_call: See comment for notifier_call_chain. |
537 | * @nr_calls: See comment for notifier_call_chain | |
eabc0694 AS |
538 | * |
539 | * Calls each function in a notifier chain in turn. The functions | |
540 | * run in a process context, so they are allowed to block. | |
541 | * | |
542 | * If the return value of the notifier can be and'ed | |
72fd4a35 | 543 | * with %NOTIFY_STOP_MASK then srcu_notifier_call_chain() |
eabc0694 AS |
544 | * will return immediately, with the return value of |
545 | * the notifier function which halted execution. | |
546 | * Otherwise the return value is the return value | |
547 | * of the last notifier function called. | |
548 | */ | |
549 | ||
6f7cc11a GS |
550 | int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, |
551 | unsigned long val, void *v, | |
552 | int nr_to_call, int *nr_calls) | |
eabc0694 AS |
553 | { |
554 | int ret; | |
555 | int idx; | |
556 | ||
557 | idx = srcu_read_lock(&nh->srcu); | |
6f7cc11a | 558 | ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls); |
eabc0694 AS |
559 | srcu_read_unlock(&nh->srcu, idx); |
560 | return ret; | |
561 | } | |
6f7cc11a | 562 | EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain); |
eabc0694 | 563 | |
6f7cc11a GS |
564 | int srcu_notifier_call_chain(struct srcu_notifier_head *nh, |
565 | unsigned long val, void *v) | |
566 | { | |
567 | return __srcu_notifier_call_chain(nh, val, v, -1, NULL); | |
568 | } | |
eabc0694 AS |
569 | EXPORT_SYMBOL_GPL(srcu_notifier_call_chain); |
570 | ||
571 | /** | |
572 | * srcu_init_notifier_head - Initialize an SRCU notifier head | |
573 | * @nh: Pointer to head of the srcu notifier chain | |
574 | * | |
575 | * Unlike other sorts of notifier heads, SRCU notifier heads require | |
576 | * dynamic initialization. Be sure to call this routine before | |
577 | * calling any of the other SRCU notifier routines for this head. | |
578 | * | |
579 | * If an SRCU notifier head is deallocated, it must first be cleaned | |
580 | * up by calling srcu_cleanup_notifier_head(). Otherwise the head's | |
581 | * per-cpu data (used by the SRCU mechanism) will leak. | |
582 | */ | |
583 | ||
584 | void srcu_init_notifier_head(struct srcu_notifier_head *nh) | |
585 | { | |
586 | mutex_init(&nh->mutex); | |
e6a92013 AS |
587 | if (init_srcu_struct(&nh->srcu) < 0) |
588 | BUG(); | |
eabc0694 AS |
589 | nh->head = NULL; |
590 | } | |
591 | ||
592 | EXPORT_SYMBOL_GPL(srcu_init_notifier_head); | |
593 | ||
1da177e4 LT |
594 | /** |
595 | * register_reboot_notifier - Register function to be called at reboot time | |
596 | * @nb: Info about notifier function to be called | |
597 | * | |
598 | * Registers a function with the list of functions | |
599 | * to be called at reboot time. | |
600 | * | |
72fd4a35 | 601 | * Currently always returns zero, as blocking_notifier_chain_register() |
1da177e4 LT |
602 | * always returns zero. |
603 | */ | |
604 | ||
605 | int register_reboot_notifier(struct notifier_block * nb) | |
606 | { | |
e041c683 | 607 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); |
1da177e4 LT |
608 | } |
609 | ||
610 | EXPORT_SYMBOL(register_reboot_notifier); | |
611 | ||
612 | /** | |
613 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
614 | * @nb: Hook to be unregistered | |
615 | * | |
616 | * Unregisters a previously registered reboot | |
617 | * notifier function. | |
618 | * | |
619 | * Returns zero on success, or %-ENOENT on failure. | |
620 | */ | |
621 | ||
622 | int unregister_reboot_notifier(struct notifier_block * nb) | |
623 | { | |
e041c683 | 624 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); |
1da177e4 LT |
625 | } |
626 | ||
627 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
628 | ||
629 | static int set_one_prio(struct task_struct *p, int niceval, int error) | |
630 | { | |
631 | int no_nice; | |
632 | ||
633 | if (p->uid != current->euid && | |
634 | p->euid != current->euid && !capable(CAP_SYS_NICE)) { | |
635 | error = -EPERM; | |
636 | goto out; | |
637 | } | |
e43379f1 | 638 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
1da177e4 LT |
639 | error = -EACCES; |
640 | goto out; | |
641 | } | |
642 | no_nice = security_task_setnice(p, niceval); | |
643 | if (no_nice) { | |
644 | error = no_nice; | |
645 | goto out; | |
646 | } | |
647 | if (error == -ESRCH) | |
648 | error = 0; | |
649 | set_user_nice(p, niceval); | |
650 | out: | |
651 | return error; | |
652 | } | |
653 | ||
654 | asmlinkage long sys_setpriority(int which, int who, int niceval) | |
655 | { | |
656 | struct task_struct *g, *p; | |
657 | struct user_struct *user; | |
658 | int error = -EINVAL; | |
41487c65 | 659 | struct pid *pgrp; |
1da177e4 LT |
660 | |
661 | if (which > 2 || which < 0) | |
662 | goto out; | |
663 | ||
664 | /* normalize: avoid signed division (rounding problems) */ | |
665 | error = -ESRCH; | |
666 | if (niceval < -20) | |
667 | niceval = -20; | |
668 | if (niceval > 19) | |
669 | niceval = 19; | |
670 | ||
671 | read_lock(&tasklist_lock); | |
672 | switch (which) { | |
673 | case PRIO_PROCESS: | |
41487c65 EB |
674 | if (who) |
675 | p = find_task_by_pid(who); | |
676 | else | |
677 | p = current; | |
1da177e4 LT |
678 | if (p) |
679 | error = set_one_prio(p, niceval, error); | |
680 | break; | |
681 | case PRIO_PGRP: | |
41487c65 EB |
682 | if (who) |
683 | pgrp = find_pid(who); | |
684 | else | |
685 | pgrp = task_pgrp(current); | |
686 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { | |
1da177e4 | 687 | error = set_one_prio(p, niceval, error); |
41487c65 | 688 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
689 | break; |
690 | case PRIO_USER: | |
691 | user = current->user; | |
692 | if (!who) | |
693 | who = current->uid; | |
694 | else | |
695 | if ((who != current->uid) && !(user = find_user(who))) | |
696 | goto out_unlock; /* No processes for this user */ | |
697 | ||
698 | do_each_thread(g, p) | |
699 | if (p->uid == who) | |
700 | error = set_one_prio(p, niceval, error); | |
701 | while_each_thread(g, p); | |
702 | if (who != current->uid) | |
703 | free_uid(user); /* For find_user() */ | |
704 | break; | |
705 | } | |
706 | out_unlock: | |
707 | read_unlock(&tasklist_lock); | |
708 | out: | |
709 | return error; | |
710 | } | |
711 | ||
712 | /* | |
713 | * Ugh. To avoid negative return values, "getpriority()" will | |
714 | * not return the normal nice-value, but a negated value that | |
715 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) | |
716 | * to stay compatible. | |
717 | */ | |
718 | asmlinkage long sys_getpriority(int which, int who) | |
719 | { | |
720 | struct task_struct *g, *p; | |
721 | struct user_struct *user; | |
722 | long niceval, retval = -ESRCH; | |
41487c65 | 723 | struct pid *pgrp; |
1da177e4 LT |
724 | |
725 | if (which > 2 || which < 0) | |
726 | return -EINVAL; | |
727 | ||
728 | read_lock(&tasklist_lock); | |
729 | switch (which) { | |
730 | case PRIO_PROCESS: | |
41487c65 EB |
731 | if (who) |
732 | p = find_task_by_pid(who); | |
733 | else | |
734 | p = current; | |
1da177e4 LT |
735 | if (p) { |
736 | niceval = 20 - task_nice(p); | |
737 | if (niceval > retval) | |
738 | retval = niceval; | |
739 | } | |
740 | break; | |
741 | case PRIO_PGRP: | |
41487c65 EB |
742 | if (who) |
743 | pgrp = find_pid(who); | |
744 | else | |
745 | pgrp = task_pgrp(current); | |
746 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { | |
1da177e4 LT |
747 | niceval = 20 - task_nice(p); |
748 | if (niceval > retval) | |
749 | retval = niceval; | |
41487c65 | 750 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1da177e4 LT |
751 | break; |
752 | case PRIO_USER: | |
753 | user = current->user; | |
754 | if (!who) | |
755 | who = current->uid; | |
756 | else | |
757 | if ((who != current->uid) && !(user = find_user(who))) | |
758 | goto out_unlock; /* No processes for this user */ | |
759 | ||
760 | do_each_thread(g, p) | |
761 | if (p->uid == who) { | |
762 | niceval = 20 - task_nice(p); | |
763 | if (niceval > retval) | |
764 | retval = niceval; | |
765 | } | |
766 | while_each_thread(g, p); | |
767 | if (who != current->uid) | |
768 | free_uid(user); /* for find_user() */ | |
769 | break; | |
770 | } | |
771 | out_unlock: | |
772 | read_unlock(&tasklist_lock); | |
773 | ||
774 | return retval; | |
775 | } | |
776 | ||
e4c94330 EB |
777 | /** |
778 | * emergency_restart - reboot the system | |
779 | * | |
780 | * Without shutting down any hardware or taking any locks | |
781 | * reboot the system. This is called when we know we are in | |
782 | * trouble so this is our best effort to reboot. This is | |
783 | * safe to call in interrupt context. | |
784 | */ | |
7c903473 EB |
785 | void emergency_restart(void) |
786 | { | |
787 | machine_emergency_restart(); | |
788 | } | |
789 | EXPORT_SYMBOL_GPL(emergency_restart); | |
790 | ||
83cc5ed3 | 791 | static void kernel_restart_prepare(char *cmd) |
4a00ea1e | 792 | { |
e041c683 | 793 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
4a00ea1e | 794 | system_state = SYSTEM_RESTART; |
4a00ea1e | 795 | device_shutdown(); |
e4c94330 | 796 | } |
1e5d5331 RD |
797 | |
798 | /** | |
799 | * kernel_restart - reboot the system | |
800 | * @cmd: pointer to buffer containing command to execute for restart | |
b8887e6e | 801 | * or %NULL |
1e5d5331 RD |
802 | * |
803 | * Shutdown everything and perform a clean reboot. | |
804 | * This is not safe to call in interrupt context. | |
805 | */ | |
e4c94330 EB |
806 | void kernel_restart(char *cmd) |
807 | { | |
808 | kernel_restart_prepare(cmd); | |
756184b7 | 809 | if (!cmd) |
4a00ea1e | 810 | printk(KERN_EMERG "Restarting system.\n"); |
756184b7 | 811 | else |
4a00ea1e | 812 | printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); |
4a00ea1e EB |
813 | machine_restart(cmd); |
814 | } | |
815 | EXPORT_SYMBOL_GPL(kernel_restart); | |
816 | ||
e4c94330 EB |
817 | /** |
818 | * kernel_kexec - reboot the system | |
819 | * | |
820 | * Move into place and start executing a preloaded standalone | |
821 | * executable. If nothing was preloaded return an error. | |
822 | */ | |
83cc5ed3 | 823 | static void kernel_kexec(void) |
4a00ea1e EB |
824 | { |
825 | #ifdef CONFIG_KEXEC | |
826 | struct kimage *image; | |
4bb8089c | 827 | image = xchg(&kexec_image, NULL); |
756184b7 | 828 | if (!image) |
4a00ea1e | 829 | return; |
e4c94330 | 830 | kernel_restart_prepare(NULL); |
4a00ea1e EB |
831 | printk(KERN_EMERG "Starting new kernel\n"); |
832 | machine_shutdown(); | |
833 | machine_kexec(image); | |
834 | #endif | |
835 | } | |
4a00ea1e | 836 | |
729b4d4c AS |
837 | void kernel_shutdown_prepare(enum system_states state) |
838 | { | |
e041c683 | 839 | blocking_notifier_call_chain(&reboot_notifier_list, |
729b4d4c AS |
840 | (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); |
841 | system_state = state; | |
842 | device_shutdown(); | |
843 | } | |
e4c94330 EB |
844 | /** |
845 | * kernel_halt - halt the system | |
846 | * | |
847 | * Shutdown everything and perform a clean system halt. | |
848 | */ | |
e4c94330 EB |
849 | void kernel_halt(void) |
850 | { | |
729b4d4c | 851 | kernel_shutdown_prepare(SYSTEM_HALT); |
4a00ea1e EB |
852 | printk(KERN_EMERG "System halted.\n"); |
853 | machine_halt(); | |
854 | } | |
729b4d4c | 855 | |
4a00ea1e EB |
856 | EXPORT_SYMBOL_GPL(kernel_halt); |
857 | ||
e4c94330 EB |
858 | /** |
859 | * kernel_power_off - power_off the system | |
860 | * | |
861 | * Shutdown everything and perform a clean system power_off. | |
862 | */ | |
e4c94330 EB |
863 | void kernel_power_off(void) |
864 | { | |
729b4d4c | 865 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
4a00ea1e EB |
866 | printk(KERN_EMERG "Power down.\n"); |
867 | machine_power_off(); | |
868 | } | |
869 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
1da177e4 LT |
870 | /* |
871 | * Reboot system call: for obvious reasons only root may call it, | |
872 | * and even root needs to set up some magic numbers in the registers | |
873 | * so that some mistake won't make this reboot the whole machine. | |
874 | * You can also set the meaning of the ctrl-alt-del-key here. | |
875 | * | |
876 | * reboot doesn't sync: do that yourself before calling this. | |
877 | */ | |
878 | asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg) | |
879 | { | |
880 | char buffer[256]; | |
881 | ||
882 | /* We only trust the superuser with rebooting the system. */ | |
883 | if (!capable(CAP_SYS_BOOT)) | |
884 | return -EPERM; | |
885 | ||
886 | /* For safety, we require "magic" arguments. */ | |
887 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
888 | (magic2 != LINUX_REBOOT_MAGIC2 && | |
889 | magic2 != LINUX_REBOOT_MAGIC2A && | |
890 | magic2 != LINUX_REBOOT_MAGIC2B && | |
891 | magic2 != LINUX_REBOOT_MAGIC2C)) | |
892 | return -EINVAL; | |
893 | ||
5e38291d EB |
894 | /* Instead of trying to make the power_off code look like |
895 | * halt when pm_power_off is not set do it the easy way. | |
896 | */ | |
897 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) | |
898 | cmd = LINUX_REBOOT_CMD_HALT; | |
899 | ||
1da177e4 LT |
900 | lock_kernel(); |
901 | switch (cmd) { | |
902 | case LINUX_REBOOT_CMD_RESTART: | |
4a00ea1e | 903 | kernel_restart(NULL); |
1da177e4 LT |
904 | break; |
905 | ||
906 | case LINUX_REBOOT_CMD_CAD_ON: | |
907 | C_A_D = 1; | |
908 | break; | |
909 | ||
910 | case LINUX_REBOOT_CMD_CAD_OFF: | |
911 | C_A_D = 0; | |
912 | break; | |
913 | ||
914 | case LINUX_REBOOT_CMD_HALT: | |
4a00ea1e | 915 | kernel_halt(); |
1da177e4 LT |
916 | unlock_kernel(); |
917 | do_exit(0); | |
918 | break; | |
919 | ||
920 | case LINUX_REBOOT_CMD_POWER_OFF: | |
4a00ea1e | 921 | kernel_power_off(); |
1da177e4 LT |
922 | unlock_kernel(); |
923 | do_exit(0); | |
924 | break; | |
925 | ||
926 | case LINUX_REBOOT_CMD_RESTART2: | |
927 | if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | |
928 | unlock_kernel(); | |
929 | return -EFAULT; | |
930 | } | |
931 | buffer[sizeof(buffer) - 1] = '\0'; | |
932 | ||
4a00ea1e | 933 | kernel_restart(buffer); |
1da177e4 LT |
934 | break; |
935 | ||
dc009d92 | 936 | case LINUX_REBOOT_CMD_KEXEC: |
4a00ea1e EB |
937 | kernel_kexec(); |
938 | unlock_kernel(); | |
939 | return -EINVAL; | |
940 | ||
1da177e4 LT |
941 | #ifdef CONFIG_SOFTWARE_SUSPEND |
942 | case LINUX_REBOOT_CMD_SW_SUSPEND: | |
943 | { | |
a3d25c27 | 944 | int ret = hibernate(); |
1da177e4 LT |
945 | unlock_kernel(); |
946 | return ret; | |
947 | } | |
948 | #endif | |
949 | ||
950 | default: | |
951 | unlock_kernel(); | |
952 | return -EINVAL; | |
953 | } | |
954 | unlock_kernel(); | |
955 | return 0; | |
956 | } | |
957 | ||
65f27f38 | 958 | static void deferred_cad(struct work_struct *dummy) |
1da177e4 | 959 | { |
abcd9e51 | 960 | kernel_restart(NULL); |
1da177e4 LT |
961 | } |
962 | ||
963 | /* | |
964 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
965 | * As it's called within an interrupt, it may NOT sync: the only choice | |
966 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
967 | */ | |
968 | void ctrl_alt_del(void) | |
969 | { | |
65f27f38 | 970 | static DECLARE_WORK(cad_work, deferred_cad); |
1da177e4 LT |
971 | |
972 | if (C_A_D) | |
973 | schedule_work(&cad_work); | |
974 | else | |
9ec52099 | 975 | kill_cad_pid(SIGINT, 1); |
1da177e4 LT |
976 | } |
977 | ||
1da177e4 LT |
978 | /* |
979 | * Unprivileged users may change the real gid to the effective gid | |
980 | * or vice versa. (BSD-style) | |
981 | * | |
982 | * If you set the real gid at all, or set the effective gid to a value not | |
983 | * equal to the real gid, then the saved gid is set to the new effective gid. | |
984 | * | |
985 | * This makes it possible for a setgid program to completely drop its | |
986 | * privileges, which is often a useful assertion to make when you are doing | |
987 | * a security audit over a program. | |
988 | * | |
989 | * The general idea is that a program which uses just setregid() will be | |
990 | * 100% compatible with BSD. A program which uses just setgid() will be | |
991 | * 100% compatible with POSIX with saved IDs. | |
992 | * | |
993 | * SMP: There are not races, the GIDs are checked only by filesystem | |
994 | * operations (as far as semantic preservation is concerned). | |
995 | */ | |
996 | asmlinkage long sys_setregid(gid_t rgid, gid_t egid) | |
997 | { | |
998 | int old_rgid = current->gid; | |
999 | int old_egid = current->egid; | |
1000 | int new_rgid = old_rgid; | |
1001 | int new_egid = old_egid; | |
1002 | int retval; | |
1003 | ||
1004 | retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE); | |
1005 | if (retval) | |
1006 | return retval; | |
1007 | ||
1008 | if (rgid != (gid_t) -1) { | |
1009 | if ((old_rgid == rgid) || | |
1010 | (current->egid==rgid) || | |
1011 | capable(CAP_SETGID)) | |
1012 | new_rgid = rgid; | |
1013 | else | |
1014 | return -EPERM; | |
1015 | } | |
1016 | if (egid != (gid_t) -1) { | |
1017 | if ((old_rgid == egid) || | |
1018 | (current->egid == egid) || | |
1019 | (current->sgid == egid) || | |
1020 | capable(CAP_SETGID)) | |
1021 | new_egid = egid; | |
756184b7 | 1022 | else |
1da177e4 | 1023 | return -EPERM; |
1da177e4 | 1024 | } |
756184b7 | 1025 | if (new_egid != old_egid) { |
d6e71144 | 1026 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1027 | smp_wmb(); |
1da177e4 LT |
1028 | } |
1029 | if (rgid != (gid_t) -1 || | |
1030 | (egid != (gid_t) -1 && egid != old_rgid)) | |
1031 | current->sgid = new_egid; | |
1032 | current->fsgid = new_egid; | |
1033 | current->egid = new_egid; | |
1034 | current->gid = new_rgid; | |
1035 | key_fsgid_changed(current); | |
9f46080c | 1036 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1037 | return 0; |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * setgid() is implemented like SysV w/ SAVED_IDS | |
1042 | * | |
1043 | * SMP: Same implicit races as above. | |
1044 | */ | |
1045 | asmlinkage long sys_setgid(gid_t gid) | |
1046 | { | |
1047 | int old_egid = current->egid; | |
1048 | int retval; | |
1049 | ||
1050 | retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID); | |
1051 | if (retval) | |
1052 | return retval; | |
1053 | ||
756184b7 CP |
1054 | if (capable(CAP_SETGID)) { |
1055 | if (old_egid != gid) { | |
d6e71144 | 1056 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1057 | smp_wmb(); |
1da177e4 LT |
1058 | } |
1059 | current->gid = current->egid = current->sgid = current->fsgid = gid; | |
756184b7 CP |
1060 | } else if ((gid == current->gid) || (gid == current->sgid)) { |
1061 | if (old_egid != gid) { | |
d6e71144 | 1062 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1063 | smp_wmb(); |
1da177e4 LT |
1064 | } |
1065 | current->egid = current->fsgid = gid; | |
1066 | } | |
1067 | else | |
1068 | return -EPERM; | |
1069 | ||
1070 | key_fsgid_changed(current); | |
9f46080c | 1071 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1072 | return 0; |
1073 | } | |
1074 | ||
1075 | static int set_user(uid_t new_ruid, int dumpclear) | |
1076 | { | |
1077 | struct user_struct *new_user; | |
1078 | ||
1079 | new_user = alloc_uid(new_ruid); | |
1080 | if (!new_user) | |
1081 | return -EAGAIN; | |
1082 | ||
1083 | if (atomic_read(&new_user->processes) >= | |
1084 | current->signal->rlim[RLIMIT_NPROC].rlim_cur && | |
1085 | new_user != &root_user) { | |
1086 | free_uid(new_user); | |
1087 | return -EAGAIN; | |
1088 | } | |
1089 | ||
1090 | switch_uid(new_user); | |
1091 | ||
756184b7 | 1092 | if (dumpclear) { |
d6e71144 | 1093 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1094 | smp_wmb(); |
1da177e4 LT |
1095 | } |
1096 | current->uid = new_ruid; | |
1097 | return 0; | |
1098 | } | |
1099 | ||
1100 | /* | |
1101 | * Unprivileged users may change the real uid to the effective uid | |
1102 | * or vice versa. (BSD-style) | |
1103 | * | |
1104 | * If you set the real uid at all, or set the effective uid to a value not | |
1105 | * equal to the real uid, then the saved uid is set to the new effective uid. | |
1106 | * | |
1107 | * This makes it possible for a setuid program to completely drop its | |
1108 | * privileges, which is often a useful assertion to make when you are doing | |
1109 | * a security audit over a program. | |
1110 | * | |
1111 | * The general idea is that a program which uses just setreuid() will be | |
1112 | * 100% compatible with BSD. A program which uses just setuid() will be | |
1113 | * 100% compatible with POSIX with saved IDs. | |
1114 | */ | |
1115 | asmlinkage long sys_setreuid(uid_t ruid, uid_t euid) | |
1116 | { | |
1117 | int old_ruid, old_euid, old_suid, new_ruid, new_euid; | |
1118 | int retval; | |
1119 | ||
1120 | retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE); | |
1121 | if (retval) | |
1122 | return retval; | |
1123 | ||
1124 | new_ruid = old_ruid = current->uid; | |
1125 | new_euid = old_euid = current->euid; | |
1126 | old_suid = current->suid; | |
1127 | ||
1128 | if (ruid != (uid_t) -1) { | |
1129 | new_ruid = ruid; | |
1130 | if ((old_ruid != ruid) && | |
1131 | (current->euid != ruid) && | |
1132 | !capable(CAP_SETUID)) | |
1133 | return -EPERM; | |
1134 | } | |
1135 | ||
1136 | if (euid != (uid_t) -1) { | |
1137 | new_euid = euid; | |
1138 | if ((old_ruid != euid) && | |
1139 | (current->euid != euid) && | |
1140 | (current->suid != euid) && | |
1141 | !capable(CAP_SETUID)) | |
1142 | return -EPERM; | |
1143 | } | |
1144 | ||
1145 | if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0) | |
1146 | return -EAGAIN; | |
1147 | ||
756184b7 | 1148 | if (new_euid != old_euid) { |
d6e71144 | 1149 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1150 | smp_wmb(); |
1da177e4 LT |
1151 | } |
1152 | current->fsuid = current->euid = new_euid; | |
1153 | if (ruid != (uid_t) -1 || | |
1154 | (euid != (uid_t) -1 && euid != old_ruid)) | |
1155 | current->suid = current->euid; | |
1156 | current->fsuid = current->euid; | |
1157 | ||
1158 | key_fsuid_changed(current); | |
9f46080c | 1159 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1160 | |
1161 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE); | |
1162 | } | |
1163 | ||
1164 | ||
1165 | ||
1166 | /* | |
1167 | * setuid() is implemented like SysV with SAVED_IDS | |
1168 | * | |
1169 | * Note that SAVED_ID's is deficient in that a setuid root program | |
1170 | * like sendmail, for example, cannot set its uid to be a normal | |
1171 | * user and then switch back, because if you're root, setuid() sets | |
1172 | * the saved uid too. If you don't like this, blame the bright people | |
1173 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() | |
1174 | * will allow a root program to temporarily drop privileges and be able to | |
1175 | * regain them by swapping the real and effective uid. | |
1176 | */ | |
1177 | asmlinkage long sys_setuid(uid_t uid) | |
1178 | { | |
1179 | int old_euid = current->euid; | |
a09c17a6 | 1180 | int old_ruid, old_suid, new_suid; |
1da177e4 LT |
1181 | int retval; |
1182 | ||
1183 | retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID); | |
1184 | if (retval) | |
1185 | return retval; | |
1186 | ||
a09c17a6 | 1187 | old_ruid = current->uid; |
1da177e4 LT |
1188 | old_suid = current->suid; |
1189 | new_suid = old_suid; | |
1190 | ||
1191 | if (capable(CAP_SETUID)) { | |
1192 | if (uid != old_ruid && set_user(uid, old_euid != uid) < 0) | |
1193 | return -EAGAIN; | |
1194 | new_suid = uid; | |
1195 | } else if ((uid != current->uid) && (uid != new_suid)) | |
1196 | return -EPERM; | |
1197 | ||
756184b7 | 1198 | if (old_euid != uid) { |
d6e71144 | 1199 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1200 | smp_wmb(); |
1da177e4 LT |
1201 | } |
1202 | current->fsuid = current->euid = uid; | |
1203 | current->suid = new_suid; | |
1204 | ||
1205 | key_fsuid_changed(current); | |
9f46080c | 1206 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1207 | |
1208 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID); | |
1209 | } | |
1210 | ||
1211 | ||
1212 | /* | |
1213 | * This function implements a generic ability to update ruid, euid, | |
1214 | * and suid. This allows you to implement the 4.4 compatible seteuid(). | |
1215 | */ | |
1216 | asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) | |
1217 | { | |
1218 | int old_ruid = current->uid; | |
1219 | int old_euid = current->euid; | |
1220 | int old_suid = current->suid; | |
1221 | int retval; | |
1222 | ||
1223 | retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES); | |
1224 | if (retval) | |
1225 | return retval; | |
1226 | ||
1227 | if (!capable(CAP_SETUID)) { | |
1228 | if ((ruid != (uid_t) -1) && (ruid != current->uid) && | |
1229 | (ruid != current->euid) && (ruid != current->suid)) | |
1230 | return -EPERM; | |
1231 | if ((euid != (uid_t) -1) && (euid != current->uid) && | |
1232 | (euid != current->euid) && (euid != current->suid)) | |
1233 | return -EPERM; | |
1234 | if ((suid != (uid_t) -1) && (suid != current->uid) && | |
1235 | (suid != current->euid) && (suid != current->suid)) | |
1236 | return -EPERM; | |
1237 | } | |
1238 | if (ruid != (uid_t) -1) { | |
1239 | if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0) | |
1240 | return -EAGAIN; | |
1241 | } | |
1242 | if (euid != (uid_t) -1) { | |
756184b7 | 1243 | if (euid != current->euid) { |
d6e71144 | 1244 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1245 | smp_wmb(); |
1da177e4 LT |
1246 | } |
1247 | current->euid = euid; | |
1248 | } | |
1249 | current->fsuid = current->euid; | |
1250 | if (suid != (uid_t) -1) | |
1251 | current->suid = suid; | |
1252 | ||
1253 | key_fsuid_changed(current); | |
9f46080c | 1254 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1255 | |
1256 | return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES); | |
1257 | } | |
1258 | ||
1259 | asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid) | |
1260 | { | |
1261 | int retval; | |
1262 | ||
1263 | if (!(retval = put_user(current->uid, ruid)) && | |
1264 | !(retval = put_user(current->euid, euid))) | |
1265 | retval = put_user(current->suid, suid); | |
1266 | ||
1267 | return retval; | |
1268 | } | |
1269 | ||
1270 | /* | |
1271 | * Same as above, but for rgid, egid, sgid. | |
1272 | */ | |
1273 | asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) | |
1274 | { | |
1275 | int retval; | |
1276 | ||
1277 | retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES); | |
1278 | if (retval) | |
1279 | return retval; | |
1280 | ||
1281 | if (!capable(CAP_SETGID)) { | |
1282 | if ((rgid != (gid_t) -1) && (rgid != current->gid) && | |
1283 | (rgid != current->egid) && (rgid != current->sgid)) | |
1284 | return -EPERM; | |
1285 | if ((egid != (gid_t) -1) && (egid != current->gid) && | |
1286 | (egid != current->egid) && (egid != current->sgid)) | |
1287 | return -EPERM; | |
1288 | if ((sgid != (gid_t) -1) && (sgid != current->gid) && | |
1289 | (sgid != current->egid) && (sgid != current->sgid)) | |
1290 | return -EPERM; | |
1291 | } | |
1292 | if (egid != (gid_t) -1) { | |
756184b7 | 1293 | if (egid != current->egid) { |
d6e71144 | 1294 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1295 | smp_wmb(); |
1da177e4 LT |
1296 | } |
1297 | current->egid = egid; | |
1298 | } | |
1299 | current->fsgid = current->egid; | |
1300 | if (rgid != (gid_t) -1) | |
1301 | current->gid = rgid; | |
1302 | if (sgid != (gid_t) -1) | |
1303 | current->sgid = sgid; | |
1304 | ||
1305 | key_fsgid_changed(current); | |
9f46080c | 1306 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1307 | return 0; |
1308 | } | |
1309 | ||
1310 | asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid) | |
1311 | { | |
1312 | int retval; | |
1313 | ||
1314 | if (!(retval = put_user(current->gid, rgid)) && | |
1315 | !(retval = put_user(current->egid, egid))) | |
1316 | retval = put_user(current->sgid, sgid); | |
1317 | ||
1318 | return retval; | |
1319 | } | |
1320 | ||
1321 | ||
1322 | /* | |
1323 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This | |
1324 | * is used for "access()" and for the NFS daemon (letting nfsd stay at | |
1325 | * whatever uid it wants to). It normally shadows "euid", except when | |
1326 | * explicitly set by setfsuid() or for access.. | |
1327 | */ | |
1328 | asmlinkage long sys_setfsuid(uid_t uid) | |
1329 | { | |
1330 | int old_fsuid; | |
1331 | ||
1332 | old_fsuid = current->fsuid; | |
1333 | if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS)) | |
1334 | return old_fsuid; | |
1335 | ||
1336 | if (uid == current->uid || uid == current->euid || | |
1337 | uid == current->suid || uid == current->fsuid || | |
756184b7 CP |
1338 | capable(CAP_SETUID)) { |
1339 | if (uid != old_fsuid) { | |
d6e71144 | 1340 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1341 | smp_wmb(); |
1da177e4 LT |
1342 | } |
1343 | current->fsuid = uid; | |
1344 | } | |
1345 | ||
1346 | key_fsuid_changed(current); | |
9f46080c | 1347 | proc_id_connector(current, PROC_EVENT_UID); |
1da177e4 LT |
1348 | |
1349 | security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS); | |
1350 | ||
1351 | return old_fsuid; | |
1352 | } | |
1353 | ||
1354 | /* | |
f42df9e6 | 1355 | * Samma på svenska.. |
1da177e4 LT |
1356 | */ |
1357 | asmlinkage long sys_setfsgid(gid_t gid) | |
1358 | { | |
1359 | int old_fsgid; | |
1360 | ||
1361 | old_fsgid = current->fsgid; | |
1362 | if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS)) | |
1363 | return old_fsgid; | |
1364 | ||
1365 | if (gid == current->gid || gid == current->egid || | |
1366 | gid == current->sgid || gid == current->fsgid || | |
756184b7 CP |
1367 | capable(CAP_SETGID)) { |
1368 | if (gid != old_fsgid) { | |
d6e71144 | 1369 | current->mm->dumpable = suid_dumpable; |
d59dd462 | 1370 | smp_wmb(); |
1da177e4 LT |
1371 | } |
1372 | current->fsgid = gid; | |
1373 | key_fsgid_changed(current); | |
9f46080c | 1374 | proc_id_connector(current, PROC_EVENT_GID); |
1da177e4 LT |
1375 | } |
1376 | return old_fsgid; | |
1377 | } | |
1378 | ||
1379 | asmlinkage long sys_times(struct tms __user * tbuf) | |
1380 | { | |
1381 | /* | |
1382 | * In the SMP world we might just be unlucky and have one of | |
1383 | * the times increment as we use it. Since the value is an | |
1384 | * atomically safe type this is just fine. Conceptually its | |
1385 | * as if the syscall took an instant longer to occur. | |
1386 | */ | |
1387 | if (tbuf) { | |
1388 | struct tms tmp; | |
35f5cad8 ON |
1389 | struct task_struct *tsk = current; |
1390 | struct task_struct *t; | |
1da177e4 LT |
1391 | cputime_t utime, stime, cutime, cstime; |
1392 | ||
7d7185c8 | 1393 | spin_lock_irq(&tsk->sighand->siglock); |
35f5cad8 ON |
1394 | utime = tsk->signal->utime; |
1395 | stime = tsk->signal->stime; | |
1396 | t = tsk; | |
1397 | do { | |
1398 | utime = cputime_add(utime, t->utime); | |
1399 | stime = cputime_add(stime, t->stime); | |
1400 | t = next_thread(t); | |
1401 | } while (t != tsk); | |
1402 | ||
35f5cad8 ON |
1403 | cutime = tsk->signal->cutime; |
1404 | cstime = tsk->signal->cstime; | |
1405 | spin_unlock_irq(&tsk->sighand->siglock); | |
1da177e4 LT |
1406 | |
1407 | tmp.tms_utime = cputime_to_clock_t(utime); | |
1408 | tmp.tms_stime = cputime_to_clock_t(stime); | |
1409 | tmp.tms_cutime = cputime_to_clock_t(cutime); | |
1410 | tmp.tms_cstime = cputime_to_clock_t(cstime); | |
1411 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) | |
1412 | return -EFAULT; | |
1413 | } | |
1414 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); | |
1415 | } | |
1416 | ||
1417 | /* | |
1418 | * This needs some heavy checking ... | |
1419 | * I just haven't the stomach for it. I also don't fully | |
1420 | * understand sessions/pgrp etc. Let somebody who does explain it. | |
1421 | * | |
1422 | * OK, I think I have the protection semantics right.... this is really | |
1423 | * only important on a multi-user system anyway, to make sure one user | |
1424 | * can't send a signal to a process owned by another. -TYT, 12/12/91 | |
1425 | * | |
1426 | * Auch. Had to add the 'did_exec' flag to conform completely to POSIX. | |
1427 | * LBT 04.03.94 | |
1428 | */ | |
1429 | ||
1430 | asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) | |
1431 | { | |
1432 | struct task_struct *p; | |
ee0acf90 | 1433 | struct task_struct *group_leader = current->group_leader; |
1da177e4 LT |
1434 | int err = -EINVAL; |
1435 | ||
1436 | if (!pid) | |
ee0acf90 | 1437 | pid = group_leader->pid; |
1da177e4 LT |
1438 | if (!pgid) |
1439 | pgid = pid; | |
1440 | if (pgid < 0) | |
1441 | return -EINVAL; | |
1442 | ||
1443 | /* From this point forward we keep holding onto the tasklist lock | |
1444 | * so that our parent does not change from under us. -DaveM | |
1445 | */ | |
1446 | write_lock_irq(&tasklist_lock); | |
1447 | ||
1448 | err = -ESRCH; | |
1449 | p = find_task_by_pid(pid); | |
1450 | if (!p) | |
1451 | goto out; | |
1452 | ||
1453 | err = -EINVAL; | |
1454 | if (!thread_group_leader(p)) | |
1455 | goto out; | |
1456 | ||
f7dd795e | 1457 | if (p->real_parent == group_leader) { |
1da177e4 | 1458 | err = -EPERM; |
41487c65 | 1459 | if (task_session(p) != task_session(group_leader)) |
1da177e4 LT |
1460 | goto out; |
1461 | err = -EACCES; | |
1462 | if (p->did_exec) | |
1463 | goto out; | |
1464 | } else { | |
1465 | err = -ESRCH; | |
ee0acf90 | 1466 | if (p != group_leader) |
1da177e4 LT |
1467 | goto out; |
1468 | } | |
1469 | ||
1470 | err = -EPERM; | |
1471 | if (p->signal->leader) | |
1472 | goto out; | |
1473 | ||
1474 | if (pgid != pid) { | |
f020bc46 ON |
1475 | struct task_struct *g = |
1476 | find_task_by_pid_type(PIDTYPE_PGID, pgid); | |
1da177e4 | 1477 | |
41487c65 | 1478 | if (!g || task_session(g) != task_session(group_leader)) |
f020bc46 | 1479 | goto out; |
1da177e4 LT |
1480 | } |
1481 | ||
1da177e4 LT |
1482 | err = security_task_setpgid(p, pgid); |
1483 | if (err) | |
1484 | goto out; | |
1485 | ||
1486 | if (process_group(p) != pgid) { | |
1487 | detach_pid(p, PIDTYPE_PGID); | |
1488 | p->signal->pgrp = pgid; | |
1489 | attach_pid(p, PIDTYPE_PGID, pgid); | |
1490 | } | |
1491 | ||
1492 | err = 0; | |
1493 | out: | |
1494 | /* All paths lead to here, thus we are safe. -DaveM */ | |
1495 | write_unlock_irq(&tasklist_lock); | |
1496 | return err; | |
1497 | } | |
1498 | ||
1499 | asmlinkage long sys_getpgid(pid_t pid) | |
1500 | { | |
756184b7 | 1501 | if (!pid) |
1da177e4 | 1502 | return process_group(current); |
756184b7 | 1503 | else { |
1da177e4 LT |
1504 | int retval; |
1505 | struct task_struct *p; | |
1506 | ||
1507 | read_lock(&tasklist_lock); | |
1508 | p = find_task_by_pid(pid); | |
1509 | ||
1510 | retval = -ESRCH; | |
1511 | if (p) { | |
1512 | retval = security_task_getpgid(p); | |
1513 | if (!retval) | |
1514 | retval = process_group(p); | |
1515 | } | |
1516 | read_unlock(&tasklist_lock); | |
1517 | return retval; | |
1518 | } | |
1519 | } | |
1520 | ||
1521 | #ifdef __ARCH_WANT_SYS_GETPGRP | |
1522 | ||
1523 | asmlinkage long sys_getpgrp(void) | |
1524 | { | |
1525 | /* SMP - assuming writes are word atomic this is fine */ | |
1526 | return process_group(current); | |
1527 | } | |
1528 | ||
1529 | #endif | |
1530 | ||
1531 | asmlinkage long sys_getsid(pid_t pid) | |
1532 | { | |
756184b7 | 1533 | if (!pid) |
937949d9 | 1534 | return process_session(current); |
756184b7 | 1535 | else { |
1da177e4 LT |
1536 | int retval; |
1537 | struct task_struct *p; | |
1538 | ||
1539 | read_lock(&tasklist_lock); | |
1540 | p = find_task_by_pid(pid); | |
1541 | ||
1542 | retval = -ESRCH; | |
756184b7 | 1543 | if (p) { |
1da177e4 LT |
1544 | retval = security_task_getsid(p); |
1545 | if (!retval) | |
937949d9 | 1546 | retval = process_session(p); |
1da177e4 LT |
1547 | } |
1548 | read_unlock(&tasklist_lock); | |
1549 | return retval; | |
1550 | } | |
1551 | } | |
1552 | ||
1553 | asmlinkage long sys_setsid(void) | |
1554 | { | |
e19f247a | 1555 | struct task_struct *group_leader = current->group_leader; |
390e2ff0 | 1556 | pid_t session; |
1da177e4 LT |
1557 | int err = -EPERM; |
1558 | ||
1da177e4 LT |
1559 | write_lock_irq(&tasklist_lock); |
1560 | ||
390e2ff0 EB |
1561 | /* Fail if I am already a session leader */ |
1562 | if (group_leader->signal->leader) | |
1563 | goto out; | |
1564 | ||
1565 | session = group_leader->pid; | |
1566 | /* Fail if a process group id already exists that equals the | |
1567 | * proposed session id. | |
1568 | * | |
1569 | * Don't check if session id == 1 because kernel threads use this | |
1570 | * session id and so the check will always fail and make it so | |
1571 | * init cannot successfully call setsid. | |
1572 | */ | |
1573 | if (session > 1 && find_task_by_pid_type(PIDTYPE_PGID, session)) | |
1da177e4 LT |
1574 | goto out; |
1575 | ||
e19f247a | 1576 | group_leader->signal->leader = 1; |
390e2ff0 | 1577 | __set_special_pids(session, session); |
24ec839c PZ |
1578 | |
1579 | spin_lock(&group_leader->sighand->siglock); | |
e19f247a | 1580 | group_leader->signal->tty = NULL; |
24ec839c PZ |
1581 | spin_unlock(&group_leader->sighand->siglock); |
1582 | ||
e19f247a | 1583 | err = process_group(group_leader); |
1da177e4 LT |
1584 | out: |
1585 | write_unlock_irq(&tasklist_lock); | |
1da177e4 LT |
1586 | return err; |
1587 | } | |
1588 | ||
1589 | /* | |
1590 | * Supplementary group IDs | |
1591 | */ | |
1592 | ||
1593 | /* init to 2 - one for init_task, one to ensure it is never freed */ | |
1594 | struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; | |
1595 | ||
1596 | struct group_info *groups_alloc(int gidsetsize) | |
1597 | { | |
1598 | struct group_info *group_info; | |
1599 | int nblocks; | |
1600 | int i; | |
1601 | ||
1602 | nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK; | |
1603 | /* Make sure we always allocate at least one indirect block pointer */ | |
1604 | nblocks = nblocks ? : 1; | |
1605 | group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER); | |
1606 | if (!group_info) | |
1607 | return NULL; | |
1608 | group_info->ngroups = gidsetsize; | |
1609 | group_info->nblocks = nblocks; | |
1610 | atomic_set(&group_info->usage, 1); | |
1611 | ||
756184b7 | 1612 | if (gidsetsize <= NGROUPS_SMALL) |
1da177e4 | 1613 | group_info->blocks[0] = group_info->small_block; |
756184b7 | 1614 | else { |
1da177e4 LT |
1615 | for (i = 0; i < nblocks; i++) { |
1616 | gid_t *b; | |
1617 | b = (void *)__get_free_page(GFP_USER); | |
1618 | if (!b) | |
1619 | goto out_undo_partial_alloc; | |
1620 | group_info->blocks[i] = b; | |
1621 | } | |
1622 | } | |
1623 | return group_info; | |
1624 | ||
1625 | out_undo_partial_alloc: | |
1626 | while (--i >= 0) { | |
1627 | free_page((unsigned long)group_info->blocks[i]); | |
1628 | } | |
1629 | kfree(group_info); | |
1630 | return NULL; | |
1631 | } | |
1632 | ||
1633 | EXPORT_SYMBOL(groups_alloc); | |
1634 | ||
1635 | void groups_free(struct group_info *group_info) | |
1636 | { | |
1637 | if (group_info->blocks[0] != group_info->small_block) { | |
1638 | int i; | |
1639 | for (i = 0; i < group_info->nblocks; i++) | |
1640 | free_page((unsigned long)group_info->blocks[i]); | |
1641 | } | |
1642 | kfree(group_info); | |
1643 | } | |
1644 | ||
1645 | EXPORT_SYMBOL(groups_free); | |
1646 | ||
1647 | /* export the group_info to a user-space array */ | |
1648 | static int groups_to_user(gid_t __user *grouplist, | |
1649 | struct group_info *group_info) | |
1650 | { | |
1651 | int i; | |
1652 | int count = group_info->ngroups; | |
1653 | ||
1654 | for (i = 0; i < group_info->nblocks; i++) { | |
1655 | int cp_count = min(NGROUPS_PER_BLOCK, count); | |
1656 | int off = i * NGROUPS_PER_BLOCK; | |
1657 | int len = cp_count * sizeof(*grouplist); | |
1658 | ||
1659 | if (copy_to_user(grouplist+off, group_info->blocks[i], len)) | |
1660 | return -EFAULT; | |
1661 | ||
1662 | count -= cp_count; | |
1663 | } | |
1664 | return 0; | |
1665 | } | |
1666 | ||
1667 | /* fill a group_info from a user-space array - it must be allocated already */ | |
1668 | static int groups_from_user(struct group_info *group_info, | |
1669 | gid_t __user *grouplist) | |
756184b7 | 1670 | { |
1da177e4 LT |
1671 | int i; |
1672 | int count = group_info->ngroups; | |
1673 | ||
1674 | for (i = 0; i < group_info->nblocks; i++) { | |
1675 | int cp_count = min(NGROUPS_PER_BLOCK, count); | |
1676 | int off = i * NGROUPS_PER_BLOCK; | |
1677 | int len = cp_count * sizeof(*grouplist); | |
1678 | ||
1679 | if (copy_from_user(group_info->blocks[i], grouplist+off, len)) | |
1680 | return -EFAULT; | |
1681 | ||
1682 | count -= cp_count; | |
1683 | } | |
1684 | return 0; | |
1685 | } | |
1686 | ||
ebe8b541 | 1687 | /* a simple Shell sort */ |
1da177e4 LT |
1688 | static void groups_sort(struct group_info *group_info) |
1689 | { | |
1690 | int base, max, stride; | |
1691 | int gidsetsize = group_info->ngroups; | |
1692 | ||
1693 | for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1) | |
1694 | ; /* nothing */ | |
1695 | stride /= 3; | |
1696 | ||
1697 | while (stride) { | |
1698 | max = gidsetsize - stride; | |
1699 | for (base = 0; base < max; base++) { | |
1700 | int left = base; | |
1701 | int right = left + stride; | |
1702 | gid_t tmp = GROUP_AT(group_info, right); | |
1703 | ||
1704 | while (left >= 0 && GROUP_AT(group_info, left) > tmp) { | |
1705 | GROUP_AT(group_info, right) = | |
1706 | GROUP_AT(group_info, left); | |
1707 | right = left; | |
1708 | left -= stride; | |
1709 | } | |
1710 | GROUP_AT(group_info, right) = tmp; | |
1711 | } | |
1712 | stride /= 3; | |
1713 | } | |
1714 | } | |
1715 | ||
1716 | /* a simple bsearch */ | |
3e30148c | 1717 | int groups_search(struct group_info *group_info, gid_t grp) |
1da177e4 | 1718 | { |
d74beb9f | 1719 | unsigned int left, right; |
1da177e4 LT |
1720 | |
1721 | if (!group_info) | |
1722 | return 0; | |
1723 | ||
1724 | left = 0; | |
1725 | right = group_info->ngroups; | |
1726 | while (left < right) { | |
d74beb9f | 1727 | unsigned int mid = (left+right)/2; |
1da177e4 LT |
1728 | int cmp = grp - GROUP_AT(group_info, mid); |
1729 | if (cmp > 0) | |
1730 | left = mid + 1; | |
1731 | else if (cmp < 0) | |
1732 | right = mid; | |
1733 | else | |
1734 | return 1; | |
1735 | } | |
1736 | return 0; | |
1737 | } | |
1738 | ||
1739 | /* validate and set current->group_info */ | |
1740 | int set_current_groups(struct group_info *group_info) | |
1741 | { | |
1742 | int retval; | |
1743 | struct group_info *old_info; | |
1744 | ||
1745 | retval = security_task_setgroups(group_info); | |
1746 | if (retval) | |
1747 | return retval; | |
1748 | ||
1749 | groups_sort(group_info); | |
1750 | get_group_info(group_info); | |
1751 | ||
1752 | task_lock(current); | |
1753 | old_info = current->group_info; | |
1754 | current->group_info = group_info; | |
1755 | task_unlock(current); | |
1756 | ||
1757 | put_group_info(old_info); | |
1758 | ||
1759 | return 0; | |
1760 | } | |
1761 | ||
1762 | EXPORT_SYMBOL(set_current_groups); | |
1763 | ||
1764 | asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist) | |
1765 | { | |
1766 | int i = 0; | |
1767 | ||
1768 | /* | |
1769 | * SMP: Nobody else can change our grouplist. Thus we are | |
1770 | * safe. | |
1771 | */ | |
1772 | ||
1773 | if (gidsetsize < 0) | |
1774 | return -EINVAL; | |
1775 | ||
1776 | /* no need to grab task_lock here; it cannot change */ | |
1da177e4 LT |
1777 | i = current->group_info->ngroups; |
1778 | if (gidsetsize) { | |
1779 | if (i > gidsetsize) { | |
1780 | i = -EINVAL; | |
1781 | goto out; | |
1782 | } | |
1783 | if (groups_to_user(grouplist, current->group_info)) { | |
1784 | i = -EFAULT; | |
1785 | goto out; | |
1786 | } | |
1787 | } | |
1788 | out: | |
1da177e4 LT |
1789 | return i; |
1790 | } | |
1791 | ||
1792 | /* | |
1793 | * SMP: Our groups are copy-on-write. We can set them safely | |
1794 | * without another task interfering. | |
1795 | */ | |
1796 | ||
1797 | asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist) | |
1798 | { | |
1799 | struct group_info *group_info; | |
1800 | int retval; | |
1801 | ||
1802 | if (!capable(CAP_SETGID)) | |
1803 | return -EPERM; | |
1804 | if ((unsigned)gidsetsize > NGROUPS_MAX) | |
1805 | return -EINVAL; | |
1806 | ||
1807 | group_info = groups_alloc(gidsetsize); | |
1808 | if (!group_info) | |
1809 | return -ENOMEM; | |
1810 | retval = groups_from_user(group_info, grouplist); | |
1811 | if (retval) { | |
1812 | put_group_info(group_info); | |
1813 | return retval; | |
1814 | } | |
1815 | ||
1816 | retval = set_current_groups(group_info); | |
1817 | put_group_info(group_info); | |
1818 | ||
1819 | return retval; | |
1820 | } | |
1821 | ||
1822 | /* | |
1823 | * Check whether we're fsgid/egid or in the supplemental group.. | |
1824 | */ | |
1825 | int in_group_p(gid_t grp) | |
1826 | { | |
1827 | int retval = 1; | |
756184b7 | 1828 | if (grp != current->fsgid) |
1da177e4 | 1829 | retval = groups_search(current->group_info, grp); |
1da177e4 LT |
1830 | return retval; |
1831 | } | |
1832 | ||
1833 | EXPORT_SYMBOL(in_group_p); | |
1834 | ||
1835 | int in_egroup_p(gid_t grp) | |
1836 | { | |
1837 | int retval = 1; | |
756184b7 | 1838 | if (grp != current->egid) |
1da177e4 | 1839 | retval = groups_search(current->group_info, grp); |
1da177e4 LT |
1840 | return retval; |
1841 | } | |
1842 | ||
1843 | EXPORT_SYMBOL(in_egroup_p); | |
1844 | ||
1845 | DECLARE_RWSEM(uts_sem); | |
1846 | ||
393b0725 DM |
1847 | EXPORT_SYMBOL(uts_sem); |
1848 | ||
1da177e4 LT |
1849 | asmlinkage long sys_newuname(struct new_utsname __user * name) |
1850 | { | |
1851 | int errno = 0; | |
1852 | ||
1853 | down_read(&uts_sem); | |
e9ff3990 | 1854 | if (copy_to_user(name, utsname(), sizeof *name)) |
1da177e4 LT |
1855 | errno = -EFAULT; |
1856 | up_read(&uts_sem); | |
1857 | return errno; | |
1858 | } | |
1859 | ||
1860 | asmlinkage long sys_sethostname(char __user *name, int len) | |
1861 | { | |
1862 | int errno; | |
1863 | char tmp[__NEW_UTS_LEN]; | |
1864 | ||
1865 | if (!capable(CAP_SYS_ADMIN)) | |
1866 | return -EPERM; | |
1867 | if (len < 0 || len > __NEW_UTS_LEN) | |
1868 | return -EINVAL; | |
1869 | down_write(&uts_sem); | |
1870 | errno = -EFAULT; | |
1871 | if (!copy_from_user(tmp, name, len)) { | |
e9ff3990 SH |
1872 | memcpy(utsname()->nodename, tmp, len); |
1873 | utsname()->nodename[len] = 0; | |
1da177e4 LT |
1874 | errno = 0; |
1875 | } | |
1876 | up_write(&uts_sem); | |
1877 | return errno; | |
1878 | } | |
1879 | ||
1880 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME | |
1881 | ||
1882 | asmlinkage long sys_gethostname(char __user *name, int len) | |
1883 | { | |
1884 | int i, errno; | |
1885 | ||
1886 | if (len < 0) | |
1887 | return -EINVAL; | |
1888 | down_read(&uts_sem); | |
e9ff3990 | 1889 | i = 1 + strlen(utsname()->nodename); |
1da177e4 LT |
1890 | if (i > len) |
1891 | i = len; | |
1892 | errno = 0; | |
e9ff3990 | 1893 | if (copy_to_user(name, utsname()->nodename, i)) |
1da177e4 LT |
1894 | errno = -EFAULT; |
1895 | up_read(&uts_sem); | |
1896 | return errno; | |
1897 | } | |
1898 | ||
1899 | #endif | |
1900 | ||
1901 | /* | |
1902 | * Only setdomainname; getdomainname can be implemented by calling | |
1903 | * uname() | |
1904 | */ | |
1905 | asmlinkage long sys_setdomainname(char __user *name, int len) | |
1906 | { | |
1907 | int errno; | |
1908 | char tmp[__NEW_UTS_LEN]; | |
1909 | ||
1910 | if (!capable(CAP_SYS_ADMIN)) | |
1911 | return -EPERM; | |
1912 | if (len < 0 || len > __NEW_UTS_LEN) | |
1913 | return -EINVAL; | |
1914 | ||
1915 | down_write(&uts_sem); | |
1916 | errno = -EFAULT; | |
1917 | if (!copy_from_user(tmp, name, len)) { | |
e9ff3990 SH |
1918 | memcpy(utsname()->domainname, tmp, len); |
1919 | utsname()->domainname[len] = 0; | |
1da177e4 LT |
1920 | errno = 0; |
1921 | } | |
1922 | up_write(&uts_sem); | |
1923 | return errno; | |
1924 | } | |
1925 | ||
1926 | asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim) | |
1927 | { | |
1928 | if (resource >= RLIM_NLIMITS) | |
1929 | return -EINVAL; | |
1930 | else { | |
1931 | struct rlimit value; | |
1932 | task_lock(current->group_leader); | |
1933 | value = current->signal->rlim[resource]; | |
1934 | task_unlock(current->group_leader); | |
1935 | return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; | |
1936 | } | |
1937 | } | |
1938 | ||
1939 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT | |
1940 | ||
1941 | /* | |
1942 | * Back compatibility for getrlimit. Needed for some apps. | |
1943 | */ | |
1944 | ||
1945 | asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim) | |
1946 | { | |
1947 | struct rlimit x; | |
1948 | if (resource >= RLIM_NLIMITS) | |
1949 | return -EINVAL; | |
1950 | ||
1951 | task_lock(current->group_leader); | |
1952 | x = current->signal->rlim[resource]; | |
1953 | task_unlock(current->group_leader); | |
756184b7 | 1954 | if (x.rlim_cur > 0x7FFFFFFF) |
1da177e4 | 1955 | x.rlim_cur = 0x7FFFFFFF; |
756184b7 | 1956 | if (x.rlim_max > 0x7FFFFFFF) |
1da177e4 LT |
1957 | x.rlim_max = 0x7FFFFFFF; |
1958 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; | |
1959 | } | |
1960 | ||
1961 | #endif | |
1962 | ||
1963 | asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim) | |
1964 | { | |
1965 | struct rlimit new_rlim, *old_rlim; | |
ec9e16ba | 1966 | unsigned long it_prof_secs; |
1da177e4 LT |
1967 | int retval; |
1968 | ||
1969 | if (resource >= RLIM_NLIMITS) | |
1970 | return -EINVAL; | |
ec9e16ba | 1971 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) |
1da177e4 | 1972 | return -EFAULT; |
ec9e16ba AM |
1973 | if (new_rlim.rlim_cur > new_rlim.rlim_max) |
1974 | return -EINVAL; | |
1da177e4 LT |
1975 | old_rlim = current->signal->rlim + resource; |
1976 | if ((new_rlim.rlim_max > old_rlim->rlim_max) && | |
1977 | !capable(CAP_SYS_RESOURCE)) | |
1978 | return -EPERM; | |
1979 | if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN) | |
ec9e16ba | 1980 | return -EPERM; |
1da177e4 LT |
1981 | |
1982 | retval = security_task_setrlimit(resource, &new_rlim); | |
1983 | if (retval) | |
1984 | return retval; | |
1985 | ||
9926e4c7 TA |
1986 | if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) { |
1987 | /* | |
1988 | * The caller is asking for an immediate RLIMIT_CPU | |
1989 | * expiry. But we use the zero value to mean "it was | |
1990 | * never set". So let's cheat and make it one second | |
1991 | * instead | |
1992 | */ | |
1993 | new_rlim.rlim_cur = 1; | |
1994 | } | |
1995 | ||
1da177e4 LT |
1996 | task_lock(current->group_leader); |
1997 | *old_rlim = new_rlim; | |
1998 | task_unlock(current->group_leader); | |
1999 | ||
ec9e16ba AM |
2000 | if (resource != RLIMIT_CPU) |
2001 | goto out; | |
d3561f78 AM |
2002 | |
2003 | /* | |
2004 | * RLIMIT_CPU handling. Note that the kernel fails to return an error | |
2005 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a | |
2006 | * very long-standing error, and fixing it now risks breakage of | |
2007 | * applications, so we live with it | |
2008 | */ | |
ec9e16ba AM |
2009 | if (new_rlim.rlim_cur == RLIM_INFINITY) |
2010 | goto out; | |
2011 | ||
2012 | it_prof_secs = cputime_to_secs(current->signal->it_prof_expires); | |
2013 | if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) { | |
e0661111 AM |
2014 | unsigned long rlim_cur = new_rlim.rlim_cur; |
2015 | cputime_t cputime; | |
ec9e16ba | 2016 | |
e0661111 | 2017 | cputime = secs_to_cputime(rlim_cur); |
1da177e4 LT |
2018 | read_lock(&tasklist_lock); |
2019 | spin_lock_irq(¤t->sighand->siglock); | |
ec9e16ba | 2020 | set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); |
1da177e4 LT |
2021 | spin_unlock_irq(¤t->sighand->siglock); |
2022 | read_unlock(&tasklist_lock); | |
2023 | } | |
ec9e16ba | 2024 | out: |
1da177e4 LT |
2025 | return 0; |
2026 | } | |
2027 | ||
2028 | /* | |
2029 | * It would make sense to put struct rusage in the task_struct, | |
2030 | * except that would make the task_struct be *really big*. After | |
2031 | * task_struct gets moved into malloc'ed memory, it would | |
2032 | * make sense to do this. It will make moving the rest of the information | |
2033 | * a lot simpler! (Which we're not doing right now because we're not | |
2034 | * measuring them yet). | |
2035 | * | |
1da177e4 LT |
2036 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have |
2037 | * races with threads incrementing their own counters. But since word | |
2038 | * reads are atomic, we either get new values or old values and we don't | |
2039 | * care which for the sums. We always take the siglock to protect reading | |
2040 | * the c* fields from p->signal from races with exit.c updating those | |
2041 | * fields when reaping, so a sample either gets all the additions of a | |
2042 | * given child after it's reaped, or none so this sample is before reaping. | |
2dd0ebcd | 2043 | * |
de047c1b RT |
2044 | * Locking: |
2045 | * We need to take the siglock for CHILDEREN, SELF and BOTH | |
2046 | * for the cases current multithreaded, non-current single threaded | |
2047 | * non-current multithreaded. Thread traversal is now safe with | |
2048 | * the siglock held. | |
2049 | * Strictly speaking, we donot need to take the siglock if we are current and | |
2050 | * single threaded, as no one else can take our signal_struct away, no one | |
2051 | * else can reap the children to update signal->c* counters, and no one else | |
2052 | * can race with the signal-> fields. If we do not take any lock, the | |
2053 | * signal-> fields could be read out of order while another thread was just | |
2054 | * exiting. So we should place a read memory barrier when we avoid the lock. | |
2055 | * On the writer side, write memory barrier is implied in __exit_signal | |
2056 | * as __exit_signal releases the siglock spinlock after updating the signal-> | |
2057 | * fields. But we don't do this yet to keep things simple. | |
2dd0ebcd | 2058 | * |
1da177e4 LT |
2059 | */ |
2060 | ||
2061 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) | |
2062 | { | |
2063 | struct task_struct *t; | |
2064 | unsigned long flags; | |
2065 | cputime_t utime, stime; | |
2066 | ||
2067 | memset((char *) r, 0, sizeof *r); | |
2dd0ebcd | 2068 | utime = stime = cputime_zero; |
1da177e4 | 2069 | |
de047c1b RT |
2070 | rcu_read_lock(); |
2071 | if (!lock_task_sighand(p, &flags)) { | |
2072 | rcu_read_unlock(); | |
2073 | return; | |
2074 | } | |
0f59cc4a | 2075 | |
1da177e4 | 2076 | switch (who) { |
0f59cc4a | 2077 | case RUSAGE_BOTH: |
1da177e4 | 2078 | case RUSAGE_CHILDREN: |
1da177e4 LT |
2079 | utime = p->signal->cutime; |
2080 | stime = p->signal->cstime; | |
2081 | r->ru_nvcsw = p->signal->cnvcsw; | |
2082 | r->ru_nivcsw = p->signal->cnivcsw; | |
2083 | r->ru_minflt = p->signal->cmin_flt; | |
2084 | r->ru_majflt = p->signal->cmaj_flt; | |
0f59cc4a ON |
2085 | |
2086 | if (who == RUSAGE_CHILDREN) | |
2087 | break; | |
2088 | ||
1da177e4 | 2089 | case RUSAGE_SELF: |
1da177e4 LT |
2090 | utime = cputime_add(utime, p->signal->utime); |
2091 | stime = cputime_add(stime, p->signal->stime); | |
2092 | r->ru_nvcsw += p->signal->nvcsw; | |
2093 | r->ru_nivcsw += p->signal->nivcsw; | |
2094 | r->ru_minflt += p->signal->min_flt; | |
2095 | r->ru_majflt += p->signal->maj_flt; | |
2096 | t = p; | |
2097 | do { | |
2098 | utime = cputime_add(utime, t->utime); | |
2099 | stime = cputime_add(stime, t->stime); | |
2100 | r->ru_nvcsw += t->nvcsw; | |
2101 | r->ru_nivcsw += t->nivcsw; | |
2102 | r->ru_minflt += t->min_flt; | |
2103 | r->ru_majflt += t->maj_flt; | |
2104 | t = next_thread(t); | |
2105 | } while (t != p); | |
1da177e4 | 2106 | break; |
0f59cc4a | 2107 | |
1da177e4 LT |
2108 | default: |
2109 | BUG(); | |
2110 | } | |
0f59cc4a | 2111 | |
de047c1b RT |
2112 | unlock_task_sighand(p, &flags); |
2113 | rcu_read_unlock(); | |
2114 | ||
0f59cc4a ON |
2115 | cputime_to_timeval(utime, &r->ru_utime); |
2116 | cputime_to_timeval(stime, &r->ru_stime); | |
1da177e4 LT |
2117 | } |
2118 | ||
2119 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) | |
2120 | { | |
2121 | struct rusage r; | |
1da177e4 | 2122 | k_getrusage(p, who, &r); |
1da177e4 LT |
2123 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; |
2124 | } | |
2125 | ||
2126 | asmlinkage long sys_getrusage(int who, struct rusage __user *ru) | |
2127 | { | |
2128 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN) | |
2129 | return -EINVAL; | |
2130 | return getrusage(current, who, ru); | |
2131 | } | |
2132 | ||
2133 | asmlinkage long sys_umask(int mask) | |
2134 | { | |
2135 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); | |
2136 | return mask; | |
2137 | } | |
2138 | ||
2139 | asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3, | |
2140 | unsigned long arg4, unsigned long arg5) | |
2141 | { | |
2142 | long error; | |
1da177e4 LT |
2143 | |
2144 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); | |
2145 | if (error) | |
2146 | return error; | |
2147 | ||
2148 | switch (option) { | |
2149 | case PR_SET_PDEATHSIG: | |
0730ded5 | 2150 | if (!valid_signal(arg2)) { |
1da177e4 LT |
2151 | error = -EINVAL; |
2152 | break; | |
2153 | } | |
0730ded5 | 2154 | current->pdeath_signal = arg2; |
1da177e4 LT |
2155 | break; |
2156 | case PR_GET_PDEATHSIG: | |
2157 | error = put_user(current->pdeath_signal, (int __user *)arg2); | |
2158 | break; | |
2159 | case PR_GET_DUMPABLE: | |
2030c0fd | 2160 | error = current->mm->dumpable; |
1da177e4 LT |
2161 | break; |
2162 | case PR_SET_DUMPABLE: | |
abf75a50 | 2163 | if (arg2 < 0 || arg2 > 1) { |
1da177e4 LT |
2164 | error = -EINVAL; |
2165 | break; | |
2166 | } | |
2167 | current->mm->dumpable = arg2; | |
2168 | break; | |
2169 | ||
2170 | case PR_SET_UNALIGN: | |
2171 | error = SET_UNALIGN_CTL(current, arg2); | |
2172 | break; | |
2173 | case PR_GET_UNALIGN: | |
2174 | error = GET_UNALIGN_CTL(current, arg2); | |
2175 | break; | |
2176 | case PR_SET_FPEMU: | |
2177 | error = SET_FPEMU_CTL(current, arg2); | |
2178 | break; | |
2179 | case PR_GET_FPEMU: | |
2180 | error = GET_FPEMU_CTL(current, arg2); | |
2181 | break; | |
2182 | case PR_SET_FPEXC: | |
2183 | error = SET_FPEXC_CTL(current, arg2); | |
2184 | break; | |
2185 | case PR_GET_FPEXC: | |
2186 | error = GET_FPEXC_CTL(current, arg2); | |
2187 | break; | |
2188 | case PR_GET_TIMING: | |
2189 | error = PR_TIMING_STATISTICAL; | |
2190 | break; | |
2191 | case PR_SET_TIMING: | |
2192 | if (arg2 == PR_TIMING_STATISTICAL) | |
2193 | error = 0; | |
2194 | else | |
2195 | error = -EINVAL; | |
2196 | break; | |
2197 | ||
2198 | case PR_GET_KEEPCAPS: | |
2199 | if (current->keep_capabilities) | |
2200 | error = 1; | |
2201 | break; | |
2202 | case PR_SET_KEEPCAPS: | |
2203 | if (arg2 != 0 && arg2 != 1) { | |
2204 | error = -EINVAL; | |
2205 | break; | |
2206 | } | |
2207 | current->keep_capabilities = arg2; | |
2208 | break; | |
2209 | case PR_SET_NAME: { | |
2210 | struct task_struct *me = current; | |
2211 | unsigned char ncomm[sizeof(me->comm)]; | |
2212 | ||
2213 | ncomm[sizeof(me->comm)-1] = 0; | |
2214 | if (strncpy_from_user(ncomm, (char __user *)arg2, | |
2215 | sizeof(me->comm)-1) < 0) | |
2216 | return -EFAULT; | |
2217 | set_task_comm(me, ncomm); | |
2218 | return 0; | |
2219 | } | |
2220 | case PR_GET_NAME: { | |
2221 | struct task_struct *me = current; | |
2222 | unsigned char tcomm[sizeof(me->comm)]; | |
2223 | ||
2224 | get_task_comm(tcomm, me); | |
2225 | if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm))) | |
2226 | return -EFAULT; | |
2227 | return 0; | |
2228 | } | |
651d765d AB |
2229 | case PR_GET_ENDIAN: |
2230 | error = GET_ENDIAN(current, arg2); | |
2231 | break; | |
2232 | case PR_SET_ENDIAN: | |
2233 | error = SET_ENDIAN(current, arg2); | |
2234 | break; | |
2235 | ||
1da177e4 LT |
2236 | default: |
2237 | error = -EINVAL; | |
2238 | break; | |
2239 | } | |
2240 | return error; | |
2241 | } | |
3cfc348b AK |
2242 | |
2243 | asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep, | |
2244 | struct getcpu_cache __user *cache) | |
2245 | { | |
2246 | int err = 0; | |
2247 | int cpu = raw_smp_processor_id(); | |
2248 | if (cpup) | |
2249 | err |= put_user(cpu, cpup); | |
2250 | if (nodep) | |
2251 | err |= put_user(cpu_to_node(cpu), nodep); | |
2252 | if (cache) { | |
2253 | /* | |
2254 | * The cache is not needed for this implementation, | |
2255 | * but make sure user programs pass something | |
2256 | * valid. vsyscall implementations can instead make | |
2257 | * good use of the cache. Only use t0 and t1 because | |
2258 | * these are available in both 32bit and 64bit ABI (no | |
2259 | * need for a compat_getcpu). 32bit has enough | |
2260 | * padding | |
2261 | */ | |
2262 | unsigned long t0, t1; | |
34596dc9 AK |
2263 | get_user(t0, &cache->blob[0]); |
2264 | get_user(t1, &cache->blob[1]); | |
3cfc348b AK |
2265 | t0++; |
2266 | t1++; | |
34596dc9 AK |
2267 | put_user(t0, &cache->blob[0]); |
2268 | put_user(t1, &cache->blob[1]); | |
3cfc348b AK |
2269 | } |
2270 | return err ? -EFAULT : 0; | |
2271 | } |