Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/posix_timers.c | |
3 | * | |
4 | * | |
5 | * 2002-10-15 Posix Clocks & timers | |
6 | * by George Anzinger george@mvista.com | |
7 | * | |
8 | * Copyright (C) 2002 2003 by MontaVista Software. | |
9 | * | |
10 | * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug. | |
11 | * Copyright (C) 2004 Boris Hu | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify | |
14 | * it under the terms of the GNU General Public License as published by | |
15 | * the Free Software Foundation; either version 2 of the License, or (at | |
16 | * your option) any later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, but | |
19 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
21 | * General Public License for more details. | |
22 | ||
23 | * You should have received a copy of the GNU General Public License | |
24 | * along with this program; if not, write to the Free Software | |
25 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
26 | * | |
27 | * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA | |
28 | */ | |
29 | ||
30 | /* These are all the functions necessary to implement | |
31 | * POSIX clocks & timers | |
32 | */ | |
33 | #include <linux/mm.h> | |
34 | #include <linux/smp_lock.h> | |
35 | #include <linux/interrupt.h> | |
36 | #include <linux/slab.h> | |
37 | #include <linux/time.h> | |
38 | ||
39 | #include <asm/uaccess.h> | |
40 | #include <asm/semaphore.h> | |
41 | #include <linux/list.h> | |
42 | #include <linux/init.h> | |
43 | #include <linux/compiler.h> | |
44 | #include <linux/idr.h> | |
45 | #include <linux/posix-timers.h> | |
46 | #include <linux/syscalls.h> | |
47 | #include <linux/wait.h> | |
48 | #include <linux/workqueue.h> | |
49 | #include <linux/module.h> | |
50 | ||
1da177e4 LT |
51 | /* |
52 | * Management arrays for POSIX timers. Timers are kept in slab memory | |
53 | * Timer ids are allocated by an external routine that keeps track of the | |
54 | * id and the timer. The external interface is: | |
55 | * | |
56 | * void *idr_find(struct idr *idp, int id); to find timer_id <id> | |
57 | * int idr_get_new(struct idr *idp, void *ptr); to get a new id and | |
58 | * related it to <ptr> | |
59 | * void idr_remove(struct idr *idp, int id); to release <id> | |
60 | * void idr_init(struct idr *idp); to initialize <idp> | |
61 | * which we supply. | |
62 | * The idr_get_new *may* call slab for more memory so it must not be | |
63 | * called under a spin lock. Likewise idr_remore may release memory | |
64 | * (but it may be ok to do this under a lock...). | |
65 | * idr_find is just a memory look up and is quite fast. A -1 return | |
66 | * indicates that the requested id does not exist. | |
67 | */ | |
68 | ||
69 | /* | |
70 | * Lets keep our timers in a slab cache :-) | |
71 | */ | |
72 | static kmem_cache_t *posix_timers_cache; | |
73 | static struct idr posix_timers_id; | |
74 | static DEFINE_SPINLOCK(idr_lock); | |
75 | ||
1da177e4 LT |
76 | /* |
77 | * we assume that the new SIGEV_THREAD_ID shares no bits with the other | |
78 | * SIGEV values. Here we put out an error if this assumption fails. | |
79 | */ | |
80 | #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \ | |
81 | ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD)) | |
82 | #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!" | |
83 | #endif | |
84 | ||
85 | ||
86 | /* | |
87 | * The timer ID is turned into a timer address by idr_find(). | |
88 | * Verifying a valid ID consists of: | |
89 | * | |
90 | * a) checking that idr_find() returns other than -1. | |
91 | * b) checking that the timer id matches the one in the timer itself. | |
92 | * c) that the timer owner is in the callers thread group. | |
93 | */ | |
94 | ||
95 | /* | |
96 | * CLOCKs: The POSIX standard calls for a couple of clocks and allows us | |
97 | * to implement others. This structure defines the various | |
98 | * clocks and allows the possibility of adding others. We | |
99 | * provide an interface to add clocks to the table and expect | |
100 | * the "arch" code to add at least one clock that is high | |
101 | * resolution. Here we define the standard CLOCK_REALTIME as a | |
102 | * 1/HZ resolution clock. | |
103 | * | |
104 | * RESOLUTION: Clock resolution is used to round up timer and interval | |
105 | * times, NOT to report clock times, which are reported with as | |
106 | * much resolution as the system can muster. In some cases this | |
107 | * resolution may depend on the underlying clock hardware and | |
108 | * may not be quantifiable until run time, and only then is the | |
109 | * necessary code is written. The standard says we should say | |
110 | * something about this issue in the documentation... | |
111 | * | |
112 | * FUNCTIONS: The CLOCKs structure defines possible functions to handle | |
113 | * various clock functions. For clocks that use the standard | |
114 | * system timer code these entries should be NULL. This will | |
115 | * allow dispatch without the overhead of indirect function | |
116 | * calls. CLOCKS that depend on other sources (e.g. WWV or GPS) | |
117 | * must supply functions here, even if the function just returns | |
118 | * ENOSYS. The standard POSIX timer management code assumes the | |
119 | * following: 1.) The k_itimer struct (sched.h) is used for the | |
120 | * timer. 2.) The list, it_lock, it_clock, it_id and it_process | |
121 | * fields are not modified by timer code. | |
122 | * | |
123 | * At this time all functions EXCEPT clock_nanosleep can be | |
124 | * redirected by the CLOCKS structure. Clock_nanosleep is in | |
125 | * there, but the code ignores it. | |
126 | * | |
127 | * Permissions: It is assumed that the clock_settime() function defined | |
128 | * for each clock will take care of permission checks. Some | |
129 | * clocks may be set able by any user (i.e. local process | |
130 | * clocks) others not. Currently the only set able clock we | |
131 | * have is CLOCK_REALTIME and its high res counter part, both of | |
132 | * which we beg off on and pass to do_sys_settimeofday(). | |
133 | */ | |
134 | ||
135 | static struct k_clock posix_clocks[MAX_CLOCKS]; | |
becf8b5d | 136 | |
1da177e4 | 137 | /* |
becf8b5d | 138 | * These ones are defined below. |
1da177e4 | 139 | */ |
becf8b5d TG |
140 | static int common_nsleep(const clockid_t, int flags, struct timespec *t, |
141 | struct timespec __user *rmtp); | |
142 | static void common_timer_get(struct k_itimer *, struct itimerspec *); | |
143 | static int common_timer_set(struct k_itimer *, int, | |
144 | struct itimerspec *, struct itimerspec *); | |
145 | static int common_timer_del(struct k_itimer *timer); | |
1da177e4 | 146 | |
becf8b5d | 147 | static int posix_timer_fn(void *data); |
1da177e4 LT |
148 | |
149 | static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags); | |
150 | ||
151 | static inline void unlock_timer(struct k_itimer *timr, unsigned long flags) | |
152 | { | |
153 | spin_unlock_irqrestore(&timr->it_lock, flags); | |
154 | } | |
155 | ||
156 | /* | |
157 | * Call the k_clock hook function if non-null, or the default function. | |
158 | */ | |
159 | #define CLOCK_DISPATCH(clock, call, arglist) \ | |
160 | ((clock) < 0 ? posix_cpu_##call arglist : \ | |
161 | (posix_clocks[clock].call != NULL \ | |
162 | ? (*posix_clocks[clock].call) arglist : common_##call arglist)) | |
163 | ||
164 | /* | |
165 | * Default clock hook functions when the struct k_clock passed | |
166 | * to register_posix_clock leaves a function pointer null. | |
167 | * | |
168 | * The function common_CALL is the default implementation for | |
169 | * the function pointer CALL in struct k_clock. | |
170 | */ | |
171 | ||
a924b04d | 172 | static inline int common_clock_getres(const clockid_t which_clock, |
1da177e4 LT |
173 | struct timespec *tp) |
174 | { | |
175 | tp->tv_sec = 0; | |
176 | tp->tv_nsec = posix_clocks[which_clock].res; | |
177 | return 0; | |
178 | } | |
179 | ||
becf8b5d TG |
180 | /* |
181 | * Get real time for posix timers | |
182 | */ | |
183 | static int common_clock_get(clockid_t which_clock, struct timespec *tp) | |
1da177e4 | 184 | { |
becf8b5d | 185 | ktime_get_real_ts(tp); |
1da177e4 LT |
186 | return 0; |
187 | } | |
188 | ||
a924b04d TG |
189 | static inline int common_clock_set(const clockid_t which_clock, |
190 | struct timespec *tp) | |
1da177e4 LT |
191 | { |
192 | return do_sys_settimeofday(tp, NULL); | |
193 | } | |
194 | ||
858119e1 | 195 | static int common_timer_create(struct k_itimer *new_timer) |
1da177e4 | 196 | { |
becf8b5d TG |
197 | hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock); |
198 | new_timer->it.real.timer.data = new_timer; | |
1da177e4 | 199 | new_timer->it.real.timer.function = posix_timer_fn; |
1da177e4 LT |
200 | return 0; |
201 | } | |
202 | ||
203 | /* | |
becf8b5d | 204 | * Return nonzero if we know a priori this clockid_t value is bogus. |
1da177e4 | 205 | */ |
a924b04d | 206 | static inline int invalid_clockid(const clockid_t which_clock) |
1da177e4 LT |
207 | { |
208 | if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */ | |
209 | return 0; | |
210 | if ((unsigned) which_clock >= MAX_CLOCKS) | |
211 | return 1; | |
212 | if (posix_clocks[which_clock].clock_getres != NULL) | |
213 | return 0; | |
1da177e4 LT |
214 | if (posix_clocks[which_clock].res != 0) |
215 | return 0; | |
1da177e4 LT |
216 | return 1; |
217 | } | |
218 | ||
becf8b5d TG |
219 | /* |
220 | * Get monotonic time for posix timers | |
221 | */ | |
222 | static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp) | |
223 | { | |
224 | ktime_get_ts(tp); | |
225 | return 0; | |
226 | } | |
1da177e4 LT |
227 | |
228 | /* | |
229 | * Initialize everything, well, just everything in Posix clocks/timers ;) | |
230 | */ | |
231 | static __init int init_posix_timers(void) | |
232 | { | |
becf8b5d TG |
233 | struct k_clock clock_realtime = { |
234 | .clock_getres = hrtimer_get_res, | |
1da177e4 | 235 | }; |
becf8b5d TG |
236 | struct k_clock clock_monotonic = { |
237 | .clock_getres = hrtimer_get_res, | |
238 | .clock_get = posix_ktime_get_ts, | |
239 | .clock_set = do_posix_clock_nosettime, | |
1da177e4 LT |
240 | }; |
241 | ||
242 | register_posix_clock(CLOCK_REALTIME, &clock_realtime); | |
243 | register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); | |
244 | ||
245 | posix_timers_cache = kmem_cache_create("posix_timers_cache", | |
246 | sizeof (struct k_itimer), 0, 0, NULL, NULL); | |
247 | idr_init(&posix_timers_id); | |
248 | return 0; | |
249 | } | |
250 | ||
251 | __initcall(init_posix_timers); | |
252 | ||
1da177e4 LT |
253 | static void schedule_next_timer(struct k_itimer *timr) |
254 | { | |
becf8b5d | 255 | if (timr->it.real.interval.tv64 == 0) |
1da177e4 LT |
256 | return; |
257 | ||
becf8b5d TG |
258 | timr->it_overrun += hrtimer_forward(&timr->it.real.timer, |
259 | timr->it.real.interval); | |
1da177e4 LT |
260 | timr->it_overrun_last = timr->it_overrun; |
261 | timr->it_overrun = -1; | |
262 | ++timr->it_requeue_pending; | |
becf8b5d | 263 | hrtimer_restart(&timr->it.real.timer); |
1da177e4 LT |
264 | } |
265 | ||
266 | /* | |
267 | * This function is exported for use by the signal deliver code. It is | |
268 | * called just prior to the info block being released and passes that | |
269 | * block to us. It's function is to update the overrun entry AND to | |
270 | * restart the timer. It should only be called if the timer is to be | |
271 | * restarted (i.e. we have flagged this in the sys_private entry of the | |
272 | * info block). | |
273 | * | |
274 | * To protect aginst the timer going away while the interrupt is queued, | |
275 | * we require that the it_requeue_pending flag be set. | |
276 | */ | |
277 | void do_schedule_next_timer(struct siginfo *info) | |
278 | { | |
279 | struct k_itimer *timr; | |
280 | unsigned long flags; | |
281 | ||
282 | timr = lock_timer(info->si_tid, &flags); | |
283 | ||
becf8b5d TG |
284 | if (timr && timr->it_requeue_pending == info->si_sys_private) { |
285 | if (timr->it_clock < 0) | |
286 | posix_cpu_timer_schedule(timr); | |
287 | else | |
288 | schedule_next_timer(timr); | |
1da177e4 | 289 | |
becf8b5d TG |
290 | info->si_overrun = timr->it_overrun_last; |
291 | } | |
292 | ||
293 | unlock_timer(timr, flags); | |
1da177e4 LT |
294 | } |
295 | ||
296 | int posix_timer_event(struct k_itimer *timr,int si_private) | |
297 | { | |
298 | memset(&timr->sigq->info, 0, sizeof(siginfo_t)); | |
299 | timr->sigq->info.si_sys_private = si_private; | |
becf8b5d | 300 | /* Send signal to the process that owns this timer.*/ |
1da177e4 LT |
301 | |
302 | timr->sigq->info.si_signo = timr->it_sigev_signo; | |
303 | timr->sigq->info.si_errno = 0; | |
304 | timr->sigq->info.si_code = SI_TIMER; | |
305 | timr->sigq->info.si_tid = timr->it_id; | |
306 | timr->sigq->info.si_value = timr->it_sigev_value; | |
e752dd6c | 307 | |
1da177e4 | 308 | if (timr->it_sigev_notify & SIGEV_THREAD_ID) { |
e752dd6c ON |
309 | struct task_struct *leader; |
310 | int ret = send_sigqueue(timr->it_sigev_signo, timr->sigq, | |
311 | timr->it_process); | |
312 | ||
313 | if (likely(ret >= 0)) | |
314 | return ret; | |
315 | ||
316 | timr->it_sigev_notify = SIGEV_SIGNAL; | |
317 | leader = timr->it_process->group_leader; | |
318 | put_task_struct(timr->it_process); | |
319 | timr->it_process = leader; | |
1da177e4 | 320 | } |
e752dd6c ON |
321 | |
322 | return send_group_sigqueue(timr->it_sigev_signo, timr->sigq, | |
323 | timr->it_process); | |
1da177e4 LT |
324 | } |
325 | EXPORT_SYMBOL_GPL(posix_timer_event); | |
326 | ||
327 | /* | |
328 | * This function gets called when a POSIX.1b interval timer expires. It | |
329 | * is used as a callback from the kernel internal timer. The | |
330 | * run_timer_list code ALWAYS calls with interrupts on. | |
331 | ||
332 | * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers. | |
333 | */ | |
becf8b5d | 334 | static int posix_timer_fn(void *data) |
1da177e4 | 335 | { |
becf8b5d | 336 | struct k_itimer *timr = data; |
1da177e4 | 337 | unsigned long flags; |
becf8b5d TG |
338 | int si_private = 0; |
339 | int ret = HRTIMER_NORESTART; | |
1da177e4 LT |
340 | |
341 | spin_lock_irqsave(&timr->it_lock, flags); | |
1da177e4 | 342 | |
becf8b5d TG |
343 | if (timr->it.real.interval.tv64 != 0) |
344 | si_private = ++timr->it_requeue_pending; | |
1da177e4 | 345 | |
becf8b5d TG |
346 | if (posix_timer_event(timr, si_private)) { |
347 | /* | |
348 | * signal was not sent because of sig_ignor | |
349 | * we will not get a call back to restart it AND | |
350 | * it should be restarted. | |
351 | */ | |
352 | if (timr->it.real.interval.tv64 != 0) { | |
353 | timr->it_overrun += | |
354 | hrtimer_forward(&timr->it.real.timer, | |
355 | timr->it.real.interval); | |
356 | ret = HRTIMER_RESTART; | |
1da177e4 | 357 | } |
1da177e4 | 358 | } |
1da177e4 | 359 | |
becf8b5d TG |
360 | unlock_timer(timr, flags); |
361 | return ret; | |
362 | } | |
1da177e4 | 363 | |
858119e1 | 364 | static struct task_struct * good_sigevent(sigevent_t * event) |
1da177e4 LT |
365 | { |
366 | struct task_struct *rtn = current->group_leader; | |
367 | ||
368 | if ((event->sigev_notify & SIGEV_THREAD_ID ) && | |
369 | (!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) || | |
370 | rtn->tgid != current->tgid || | |
371 | (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) | |
372 | return NULL; | |
373 | ||
374 | if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) && | |
375 | ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX))) | |
376 | return NULL; | |
377 | ||
378 | return rtn; | |
379 | } | |
380 | ||
a924b04d | 381 | void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock) |
1da177e4 LT |
382 | { |
383 | if ((unsigned) clock_id >= MAX_CLOCKS) { | |
384 | printk("POSIX clock register failed for clock_id %d\n", | |
385 | clock_id); | |
386 | return; | |
387 | } | |
388 | ||
389 | posix_clocks[clock_id] = *new_clock; | |
390 | } | |
391 | EXPORT_SYMBOL_GPL(register_posix_clock); | |
392 | ||
393 | static struct k_itimer * alloc_posix_timer(void) | |
394 | { | |
395 | struct k_itimer *tmr; | |
396 | tmr = kmem_cache_alloc(posix_timers_cache, GFP_KERNEL); | |
397 | if (!tmr) | |
398 | return tmr; | |
399 | memset(tmr, 0, sizeof (struct k_itimer)); | |
400 | if (unlikely(!(tmr->sigq = sigqueue_alloc()))) { | |
401 | kmem_cache_free(posix_timers_cache, tmr); | |
402 | tmr = NULL; | |
403 | } | |
404 | return tmr; | |
405 | } | |
406 | ||
407 | #define IT_ID_SET 1 | |
408 | #define IT_ID_NOT_SET 0 | |
409 | static void release_posix_timer(struct k_itimer *tmr, int it_id_set) | |
410 | { | |
411 | if (it_id_set) { | |
412 | unsigned long flags; | |
413 | spin_lock_irqsave(&idr_lock, flags); | |
414 | idr_remove(&posix_timers_id, tmr->it_id); | |
415 | spin_unlock_irqrestore(&idr_lock, flags); | |
416 | } | |
417 | sigqueue_free(tmr->sigq); | |
418 | if (unlikely(tmr->it_process) && | |
419 | tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) | |
420 | put_task_struct(tmr->it_process); | |
421 | kmem_cache_free(posix_timers_cache, tmr); | |
422 | } | |
423 | ||
424 | /* Create a POSIX.1b interval timer. */ | |
425 | ||
426 | asmlinkage long | |
a924b04d | 427 | sys_timer_create(const clockid_t which_clock, |
1da177e4 LT |
428 | struct sigevent __user *timer_event_spec, |
429 | timer_t __user * created_timer_id) | |
430 | { | |
431 | int error = 0; | |
432 | struct k_itimer *new_timer = NULL; | |
433 | int new_timer_id; | |
434 | struct task_struct *process = NULL; | |
435 | unsigned long flags; | |
436 | sigevent_t event; | |
437 | int it_id_set = IT_ID_NOT_SET; | |
438 | ||
439 | if (invalid_clockid(which_clock)) | |
440 | return -EINVAL; | |
441 | ||
442 | new_timer = alloc_posix_timer(); | |
443 | if (unlikely(!new_timer)) | |
444 | return -EAGAIN; | |
445 | ||
446 | spin_lock_init(&new_timer->it_lock); | |
447 | retry: | |
448 | if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) { | |
449 | error = -EAGAIN; | |
450 | goto out; | |
451 | } | |
452 | spin_lock_irq(&idr_lock); | |
becf8b5d | 453 | error = idr_get_new(&posix_timers_id, (void *) new_timer, |
1da177e4 LT |
454 | &new_timer_id); |
455 | spin_unlock_irq(&idr_lock); | |
456 | if (error == -EAGAIN) | |
457 | goto retry; | |
458 | else if (error) { | |
459 | /* | |
460 | * Wierd looking, but we return EAGAIN if the IDR is | |
461 | * full (proper POSIX return value for this) | |
462 | */ | |
463 | error = -EAGAIN; | |
464 | goto out; | |
465 | } | |
466 | ||
467 | it_id_set = IT_ID_SET; | |
468 | new_timer->it_id = (timer_t) new_timer_id; | |
469 | new_timer->it_clock = which_clock; | |
470 | new_timer->it_overrun = -1; | |
471 | error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer)); | |
472 | if (error) | |
473 | goto out; | |
474 | ||
475 | /* | |
476 | * return the timer_id now. The next step is hard to | |
477 | * back out if there is an error. | |
478 | */ | |
479 | if (copy_to_user(created_timer_id, | |
480 | &new_timer_id, sizeof (new_timer_id))) { | |
481 | error = -EFAULT; | |
482 | goto out; | |
483 | } | |
484 | if (timer_event_spec) { | |
485 | if (copy_from_user(&event, timer_event_spec, sizeof (event))) { | |
486 | error = -EFAULT; | |
487 | goto out; | |
488 | } | |
489 | new_timer->it_sigev_notify = event.sigev_notify; | |
490 | new_timer->it_sigev_signo = event.sigev_signo; | |
491 | new_timer->it_sigev_value = event.sigev_value; | |
492 | ||
493 | read_lock(&tasklist_lock); | |
494 | if ((process = good_sigevent(&event))) { | |
495 | /* | |
496 | * We may be setting up this process for another | |
497 | * thread. It may be exiting. To catch this | |
498 | * case the we check the PF_EXITING flag. If | |
499 | * the flag is not set, the siglock will catch | |
500 | * him before it is too late (in exit_itimers). | |
501 | * | |
502 | * The exec case is a bit more invloved but easy | |
503 | * to code. If the process is in our thread | |
504 | * group (and it must be or we would not allow | |
505 | * it here) and is doing an exec, it will cause | |
506 | * us to be killed. In this case it will wait | |
507 | * for us to die which means we can finish this | |
508 | * linkage with our last gasp. I.e. no code :) | |
509 | */ | |
510 | spin_lock_irqsave(&process->sighand->siglock, flags); | |
511 | if (!(process->flags & PF_EXITING)) { | |
512 | new_timer->it_process = process; | |
513 | list_add(&new_timer->list, | |
514 | &process->signal->posix_timers); | |
515 | spin_unlock_irqrestore(&process->sighand->siglock, flags); | |
516 | if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) | |
517 | get_task_struct(process); | |
518 | } else { | |
519 | spin_unlock_irqrestore(&process->sighand->siglock, flags); | |
520 | process = NULL; | |
521 | } | |
522 | } | |
523 | read_unlock(&tasklist_lock); | |
524 | if (!process) { | |
525 | error = -EINVAL; | |
526 | goto out; | |
527 | } | |
528 | } else { | |
529 | new_timer->it_sigev_notify = SIGEV_SIGNAL; | |
530 | new_timer->it_sigev_signo = SIGALRM; | |
531 | new_timer->it_sigev_value.sival_int = new_timer->it_id; | |
532 | process = current->group_leader; | |
533 | spin_lock_irqsave(&process->sighand->siglock, flags); | |
534 | new_timer->it_process = process; | |
535 | list_add(&new_timer->list, &process->signal->posix_timers); | |
536 | spin_unlock_irqrestore(&process->sighand->siglock, flags); | |
537 | } | |
538 | ||
539 | /* | |
540 | * In the case of the timer belonging to another task, after | |
541 | * the task is unlocked, the timer is owned by the other task | |
542 | * and may cease to exist at any time. Don't use or modify | |
543 | * new_timer after the unlock call. | |
544 | */ | |
545 | ||
546 | out: | |
547 | if (error) | |
548 | release_posix_timer(new_timer, it_id_set); | |
549 | ||
550 | return error; | |
551 | } | |
552 | ||
1da177e4 LT |
553 | /* |
554 | * Locking issues: We need to protect the result of the id look up until | |
555 | * we get the timer locked down so it is not deleted under us. The | |
556 | * removal is done under the idr spinlock so we use that here to bridge | |
557 | * the find to the timer lock. To avoid a dead lock, the timer id MUST | |
558 | * be release with out holding the timer lock. | |
559 | */ | |
560 | static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) | |
561 | { | |
562 | struct k_itimer *timr; | |
563 | /* | |
564 | * Watch out here. We do a irqsave on the idr_lock and pass the | |
565 | * flags part over to the timer lock. Must not let interrupts in | |
566 | * while we are moving the lock. | |
567 | */ | |
568 | ||
569 | spin_lock_irqsave(&idr_lock, *flags); | |
570 | timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id); | |
571 | if (timr) { | |
572 | spin_lock(&timr->it_lock); | |
573 | spin_unlock(&idr_lock); | |
574 | ||
575 | if ((timr->it_id != timer_id) || !(timr->it_process) || | |
576 | timr->it_process->tgid != current->tgid) { | |
577 | unlock_timer(timr, *flags); | |
578 | timr = NULL; | |
579 | } | |
580 | } else | |
581 | spin_unlock_irqrestore(&idr_lock, *flags); | |
582 | ||
583 | return timr; | |
584 | } | |
585 | ||
586 | /* | |
587 | * Get the time remaining on a POSIX.1b interval timer. This function | |
588 | * is ALWAYS called with spin_lock_irq on the timer, thus it must not | |
589 | * mess with irq. | |
590 | * | |
591 | * We have a couple of messes to clean up here. First there is the case | |
592 | * of a timer that has a requeue pending. These timers should appear to | |
593 | * be in the timer list with an expiry as if we were to requeue them | |
594 | * now. | |
595 | * | |
596 | * The second issue is the SIGEV_NONE timer which may be active but is | |
597 | * not really ever put in the timer list (to save system resources). | |
598 | * This timer may be expired, and if so, we will do it here. Otherwise | |
599 | * it is the same as a requeue pending timer WRT to what we should | |
600 | * report. | |
601 | */ | |
602 | static void | |
603 | common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) | |
604 | { | |
becf8b5d TG |
605 | ktime_t remaining; |
606 | struct hrtimer *timer = &timr->it.real.timer; | |
1da177e4 | 607 | |
becf8b5d TG |
608 | memset(cur_setting, 0, sizeof(struct itimerspec)); |
609 | remaining = hrtimer_get_remaining(timer); | |
610 | ||
611 | /* Time left ? or timer pending */ | |
612 | if (remaining.tv64 > 0 || hrtimer_active(timer)) | |
613 | goto calci; | |
614 | /* interval timer ? */ | |
615 | if (timr->it.real.interval.tv64 == 0) | |
616 | return; | |
617 | /* | |
618 | * When a requeue is pending or this is a SIGEV_NONE timer | |
619 | * move the expiry time forward by intervals, so expiry is > | |
620 | * now. | |
621 | */ | |
622 | if (timr->it_requeue_pending & REQUEUE_PENDING || | |
623 | (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { | |
624 | timr->it_overrun += | |
625 | hrtimer_forward(timer, timr->it.real.interval); | |
626 | remaining = hrtimer_get_remaining(timer); | |
1da177e4 | 627 | } |
becf8b5d TG |
628 | calci: |
629 | /* interval timer ? */ | |
630 | if (timr->it.real.interval.tv64 != 0) | |
631 | cur_setting->it_interval = | |
632 | ktime_to_timespec(timr->it.real.interval); | |
633 | /* Return 0 only, when the timer is expired and not pending */ | |
634 | if (remaining.tv64 <= 0) | |
635 | cur_setting->it_value.tv_nsec = 1; | |
636 | else | |
637 | cur_setting->it_value = ktime_to_timespec(remaining); | |
1da177e4 LT |
638 | } |
639 | ||
640 | /* Get the time remaining on a POSIX.1b interval timer. */ | |
641 | asmlinkage long | |
642 | sys_timer_gettime(timer_t timer_id, struct itimerspec __user *setting) | |
643 | { | |
644 | struct k_itimer *timr; | |
645 | struct itimerspec cur_setting; | |
646 | unsigned long flags; | |
647 | ||
648 | timr = lock_timer(timer_id, &flags); | |
649 | if (!timr) | |
650 | return -EINVAL; | |
651 | ||
652 | CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting)); | |
653 | ||
654 | unlock_timer(timr, flags); | |
655 | ||
656 | if (copy_to_user(setting, &cur_setting, sizeof (cur_setting))) | |
657 | return -EFAULT; | |
658 | ||
659 | return 0; | |
660 | } | |
becf8b5d | 661 | |
1da177e4 LT |
662 | /* |
663 | * Get the number of overruns of a POSIX.1b interval timer. This is to | |
664 | * be the overrun of the timer last delivered. At the same time we are | |
665 | * accumulating overruns on the next timer. The overrun is frozen when | |
666 | * the signal is delivered, either at the notify time (if the info block | |
667 | * is not queued) or at the actual delivery time (as we are informed by | |
668 | * the call back to do_schedule_next_timer(). So all we need to do is | |
669 | * to pick up the frozen overrun. | |
670 | */ | |
1da177e4 LT |
671 | asmlinkage long |
672 | sys_timer_getoverrun(timer_t timer_id) | |
673 | { | |
674 | struct k_itimer *timr; | |
675 | int overrun; | |
676 | long flags; | |
677 | ||
678 | timr = lock_timer(timer_id, &flags); | |
679 | if (!timr) | |
680 | return -EINVAL; | |
681 | ||
682 | overrun = timr->it_overrun_last; | |
683 | unlock_timer(timr, flags); | |
684 | ||
685 | return overrun; | |
686 | } | |
1da177e4 LT |
687 | |
688 | /* Set a POSIX.1b interval timer. */ | |
689 | /* timr->it_lock is taken. */ | |
858119e1 | 690 | static int |
1da177e4 LT |
691 | common_timer_set(struct k_itimer *timr, int flags, |
692 | struct itimerspec *new_setting, struct itimerspec *old_setting) | |
693 | { | |
becf8b5d | 694 | struct hrtimer *timer = &timr->it.real.timer; |
1da177e4 LT |
695 | |
696 | if (old_setting) | |
697 | common_timer_get(timr, old_setting); | |
698 | ||
699 | /* disable the timer */ | |
becf8b5d | 700 | timr->it.real.interval.tv64 = 0; |
1da177e4 LT |
701 | /* |
702 | * careful here. If smp we could be in the "fire" routine which will | |
703 | * be spinning as we hold the lock. But this is ONLY an SMP issue. | |
704 | */ | |
becf8b5d | 705 | if (hrtimer_try_to_cancel(timer) < 0) |
1da177e4 | 706 | return TIMER_RETRY; |
1da177e4 LT |
707 | |
708 | timr->it_requeue_pending = (timr->it_requeue_pending + 2) & | |
709 | ~REQUEUE_PENDING; | |
710 | timr->it_overrun_last = 0; | |
1da177e4 | 711 | |
becf8b5d TG |
712 | /* switch off the timer when it_value is zero */ |
713 | if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) | |
714 | return 0; | |
1da177e4 | 715 | |
becf8b5d TG |
716 | /* Posix madness. Only absolute CLOCK_REALTIME timers |
717 | * are affected by clock sets. So we must reiniatilize | |
718 | * the timer. | |
1da177e4 | 719 | */ |
becf8b5d TG |
720 | if (timr->it_clock == CLOCK_REALTIME && (flags & TIMER_ABSTIME)) |
721 | hrtimer_rebase(timer, CLOCK_REALTIME); | |
722 | else | |
723 | hrtimer_rebase(timer, CLOCK_MONOTONIC); | |
724 | ||
725 | timer->expires = timespec_to_ktime(new_setting->it_value); | |
726 | ||
727 | /* Convert interval */ | |
728 | timr->it.real.interval = timespec_to_ktime(new_setting->it_interval); | |
729 | ||
730 | /* SIGEV_NONE timers are not queued ! See common_timer_get */ | |
731 | if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) | |
732 | return 0; | |
733 | ||
734 | hrtimer_start(timer, timer->expires, (flags & TIMER_ABSTIME) ? | |
735 | HRTIMER_ABS : HRTIMER_REL); | |
1da177e4 LT |
736 | return 0; |
737 | } | |
738 | ||
739 | /* Set a POSIX.1b interval timer */ | |
740 | asmlinkage long | |
741 | sys_timer_settime(timer_t timer_id, int flags, | |
742 | const struct itimerspec __user *new_setting, | |
743 | struct itimerspec __user *old_setting) | |
744 | { | |
745 | struct k_itimer *timr; | |
746 | struct itimerspec new_spec, old_spec; | |
747 | int error = 0; | |
748 | long flag; | |
749 | struct itimerspec *rtn = old_setting ? &old_spec : NULL; | |
750 | ||
751 | if (!new_setting) | |
752 | return -EINVAL; | |
753 | ||
754 | if (copy_from_user(&new_spec, new_setting, sizeof (new_spec))) | |
755 | return -EFAULT; | |
756 | ||
becf8b5d TG |
757 | if (!timespec_valid(&new_spec.it_interval) || |
758 | !timespec_valid(&new_spec.it_value)) | |
1da177e4 LT |
759 | return -EINVAL; |
760 | retry: | |
761 | timr = lock_timer(timer_id, &flag); | |
762 | if (!timr) | |
763 | return -EINVAL; | |
764 | ||
765 | error = CLOCK_DISPATCH(timr->it_clock, timer_set, | |
766 | (timr, flags, &new_spec, rtn)); | |
767 | ||
768 | unlock_timer(timr, flag); | |
769 | if (error == TIMER_RETRY) { | |
770 | rtn = NULL; // We already got the old time... | |
771 | goto retry; | |
772 | } | |
773 | ||
becf8b5d TG |
774 | if (old_setting && !error && |
775 | copy_to_user(old_setting, &old_spec, sizeof (old_spec))) | |
1da177e4 LT |
776 | error = -EFAULT; |
777 | ||
778 | return error; | |
779 | } | |
780 | ||
781 | static inline int common_timer_del(struct k_itimer *timer) | |
782 | { | |
becf8b5d | 783 | timer->it.real.interval.tv64 = 0; |
f972be33 | 784 | |
becf8b5d | 785 | if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0) |
1da177e4 | 786 | return TIMER_RETRY; |
1da177e4 LT |
787 | return 0; |
788 | } | |
789 | ||
790 | static inline int timer_delete_hook(struct k_itimer *timer) | |
791 | { | |
792 | return CLOCK_DISPATCH(timer->it_clock, timer_del, (timer)); | |
793 | } | |
794 | ||
795 | /* Delete a POSIX.1b interval timer. */ | |
796 | asmlinkage long | |
797 | sys_timer_delete(timer_t timer_id) | |
798 | { | |
799 | struct k_itimer *timer; | |
800 | long flags; | |
801 | ||
1da177e4 | 802 | retry_delete: |
1da177e4 LT |
803 | timer = lock_timer(timer_id, &flags); |
804 | if (!timer) | |
805 | return -EINVAL; | |
806 | ||
becf8b5d | 807 | if (timer_delete_hook(timer) == TIMER_RETRY) { |
1da177e4 LT |
808 | unlock_timer(timer, flags); |
809 | goto retry_delete; | |
810 | } | |
becf8b5d | 811 | |
1da177e4 LT |
812 | spin_lock(¤t->sighand->siglock); |
813 | list_del(&timer->list); | |
814 | spin_unlock(¤t->sighand->siglock); | |
815 | /* | |
816 | * This keeps any tasks waiting on the spin lock from thinking | |
817 | * they got something (see the lock code above). | |
818 | */ | |
819 | if (timer->it_process) { | |
820 | if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) | |
821 | put_task_struct(timer->it_process); | |
822 | timer->it_process = NULL; | |
823 | } | |
824 | unlock_timer(timer, flags); | |
825 | release_posix_timer(timer, IT_ID_SET); | |
826 | return 0; | |
827 | } | |
becf8b5d | 828 | |
1da177e4 LT |
829 | /* |
830 | * return timer owned by the process, used by exit_itimers | |
831 | */ | |
858119e1 | 832 | static void itimer_delete(struct k_itimer *timer) |
1da177e4 LT |
833 | { |
834 | unsigned long flags; | |
835 | ||
1da177e4 | 836 | retry_delete: |
1da177e4 LT |
837 | spin_lock_irqsave(&timer->it_lock, flags); |
838 | ||
becf8b5d | 839 | if (timer_delete_hook(timer) == TIMER_RETRY) { |
1da177e4 LT |
840 | unlock_timer(timer, flags); |
841 | goto retry_delete; | |
842 | } | |
1da177e4 LT |
843 | list_del(&timer->list); |
844 | /* | |
845 | * This keeps any tasks waiting on the spin lock from thinking | |
846 | * they got something (see the lock code above). | |
847 | */ | |
848 | if (timer->it_process) { | |
849 | if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) | |
850 | put_task_struct(timer->it_process); | |
851 | timer->it_process = NULL; | |
852 | } | |
853 | unlock_timer(timer, flags); | |
854 | release_posix_timer(timer, IT_ID_SET); | |
855 | } | |
856 | ||
857 | /* | |
25f407f0 | 858 | * This is called by do_exit or de_thread, only when there are no more |
1da177e4 LT |
859 | * references to the shared signal_struct. |
860 | */ | |
861 | void exit_itimers(struct signal_struct *sig) | |
862 | { | |
863 | struct k_itimer *tmr; | |
864 | ||
865 | while (!list_empty(&sig->posix_timers)) { | |
866 | tmr = list_entry(sig->posix_timers.next, struct k_itimer, list); | |
867 | itimer_delete(tmr); | |
868 | } | |
869 | } | |
870 | ||
becf8b5d | 871 | /* Not available / possible... functions */ |
a924b04d | 872 | int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp) |
1da177e4 LT |
873 | { |
874 | return -EINVAL; | |
875 | } | |
876 | EXPORT_SYMBOL_GPL(do_posix_clock_nosettime); | |
877 | ||
878 | int do_posix_clock_notimer_create(struct k_itimer *timer) | |
879 | { | |
880 | return -EINVAL; | |
881 | } | |
882 | EXPORT_SYMBOL_GPL(do_posix_clock_notimer_create); | |
883 | ||
a924b04d | 884 | int do_posix_clock_nonanosleep(const clockid_t clock, int flags, |
97735f25 | 885 | struct timespec *t, struct timespec __user *r) |
1da177e4 LT |
886 | { |
887 | #ifndef ENOTSUP | |
888 | return -EOPNOTSUPP; /* aka ENOTSUP in userland for POSIX */ | |
889 | #else /* parisc does define it separately. */ | |
890 | return -ENOTSUP; | |
891 | #endif | |
892 | } | |
893 | EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep); | |
894 | ||
a924b04d TG |
895 | asmlinkage long sys_clock_settime(const clockid_t which_clock, |
896 | const struct timespec __user *tp) | |
1da177e4 LT |
897 | { |
898 | struct timespec new_tp; | |
899 | ||
900 | if (invalid_clockid(which_clock)) | |
901 | return -EINVAL; | |
902 | if (copy_from_user(&new_tp, tp, sizeof (*tp))) | |
903 | return -EFAULT; | |
904 | ||
905 | return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp)); | |
906 | } | |
907 | ||
908 | asmlinkage long | |
a924b04d | 909 | sys_clock_gettime(const clockid_t which_clock, struct timespec __user *tp) |
1da177e4 LT |
910 | { |
911 | struct timespec kernel_tp; | |
912 | int error; | |
913 | ||
914 | if (invalid_clockid(which_clock)) | |
915 | return -EINVAL; | |
916 | error = CLOCK_DISPATCH(which_clock, clock_get, | |
917 | (which_clock, &kernel_tp)); | |
918 | if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp))) | |
919 | error = -EFAULT; | |
920 | ||
921 | return error; | |
922 | ||
923 | } | |
924 | ||
925 | asmlinkage long | |
a924b04d | 926 | sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp) |
1da177e4 LT |
927 | { |
928 | struct timespec rtn_tp; | |
929 | int error; | |
930 | ||
931 | if (invalid_clockid(which_clock)) | |
932 | return -EINVAL; | |
933 | ||
934 | error = CLOCK_DISPATCH(which_clock, clock_getres, | |
935 | (which_clock, &rtn_tp)); | |
936 | ||
937 | if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp))) { | |
938 | error = -EFAULT; | |
939 | } | |
940 | ||
941 | return error; | |
942 | } | |
943 | ||
97735f25 TG |
944 | /* |
945 | * nanosleep for monotonic and realtime clocks | |
946 | */ | |
947 | static int common_nsleep(const clockid_t which_clock, int flags, | |
948 | struct timespec *tsave, struct timespec __user *rmtp) | |
949 | { | |
950 | int mode = flags & TIMER_ABSTIME ? HRTIMER_ABS : HRTIMER_REL; | |
951 | int clockid = which_clock; | |
952 | ||
953 | switch (which_clock) { | |
954 | case CLOCK_REALTIME: | |
955 | /* Posix madness. Only absolute timers on clock realtime | |
956 | are affected by clock set. */ | |
becf8b5d | 957 | if (mode != HRTIMER_ABS) |
97735f25 TG |
958 | clockid = CLOCK_MONOTONIC; |
959 | case CLOCK_MONOTONIC: | |
960 | break; | |
961 | default: | |
962 | return -EINVAL; | |
963 | } | |
964 | return hrtimer_nanosleep(tsave, rmtp, mode, clockid); | |
965 | } | |
1da177e4 LT |
966 | |
967 | asmlinkage long | |
a924b04d | 968 | sys_clock_nanosleep(const clockid_t which_clock, int flags, |
1da177e4 LT |
969 | const struct timespec __user *rqtp, |
970 | struct timespec __user *rmtp) | |
971 | { | |
972 | struct timespec t; | |
1da177e4 LT |
973 | |
974 | if (invalid_clockid(which_clock)) | |
975 | return -EINVAL; | |
976 | ||
977 | if (copy_from_user(&t, rqtp, sizeof (struct timespec))) | |
978 | return -EFAULT; | |
979 | ||
5f82b2b7 | 980 | if (!timespec_valid(&t)) |
1da177e4 LT |
981 | return -EINVAL; |
982 | ||
97735f25 TG |
983 | return CLOCK_DISPATCH(which_clock, nsleep, |
984 | (which_clock, flags, &t, rmtp)); | |
1da177e4 | 985 | } |