Commit | Line | Data |
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1da177e4 | 1 | /* |
f30c2269 | 2 | * linux/kernel/posix-timers.c |
1da177e4 LT |
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> | |
1da177e4 LT |
34 | #include <linux/interrupt.h> |
35 | #include <linux/slab.h> | |
36 | #include <linux/time.h> | |
97d1f15b | 37 | #include <linux/mutex.h> |
1da177e4 LT |
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 | */ | |
e18b890b | 72 | static struct kmem_cache *posix_timers_cache; |
1da177e4 LT |
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 | |
c9cb2e3d | 147 | static enum hrtimer_restart posix_timer_fn(struct hrtimer *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 | { |
7978672c | 197 | hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); |
1da177e4 LT |
198 | return 0; |
199 | } | |
200 | ||
201 | /* | |
becf8b5d | 202 | * Return nonzero if we know a priori this clockid_t value is bogus. |
1da177e4 | 203 | */ |
a924b04d | 204 | static inline int invalid_clockid(const clockid_t which_clock) |
1da177e4 LT |
205 | { |
206 | if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */ | |
207 | return 0; | |
208 | if ((unsigned) which_clock >= MAX_CLOCKS) | |
209 | return 1; | |
210 | if (posix_clocks[which_clock].clock_getres != NULL) | |
211 | return 0; | |
1da177e4 LT |
212 | if (posix_clocks[which_clock].res != 0) |
213 | return 0; | |
1da177e4 LT |
214 | return 1; |
215 | } | |
216 | ||
becf8b5d TG |
217 | /* |
218 | * Get monotonic time for posix timers | |
219 | */ | |
220 | static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp) | |
221 | { | |
222 | ktime_get_ts(tp); | |
223 | return 0; | |
224 | } | |
1da177e4 LT |
225 | |
226 | /* | |
227 | * Initialize everything, well, just everything in Posix clocks/timers ;) | |
228 | */ | |
229 | static __init int init_posix_timers(void) | |
230 | { | |
becf8b5d TG |
231 | struct k_clock clock_realtime = { |
232 | .clock_getres = hrtimer_get_res, | |
1da177e4 | 233 | }; |
becf8b5d TG |
234 | struct k_clock clock_monotonic = { |
235 | .clock_getres = hrtimer_get_res, | |
236 | .clock_get = posix_ktime_get_ts, | |
237 | .clock_set = do_posix_clock_nosettime, | |
1da177e4 LT |
238 | }; |
239 | ||
240 | register_posix_clock(CLOCK_REALTIME, &clock_realtime); | |
241 | register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); | |
242 | ||
243 | posix_timers_cache = kmem_cache_create("posix_timers_cache", | |
040b5c6f AD |
244 | sizeof (struct k_itimer), 0, SLAB_PANIC, |
245 | NULL); | |
1da177e4 LT |
246 | idr_init(&posix_timers_id); |
247 | return 0; | |
248 | } | |
249 | ||
250 | __initcall(init_posix_timers); | |
251 | ||
1da177e4 LT |
252 | static void schedule_next_timer(struct k_itimer *timr) |
253 | { | |
44f21475 RZ |
254 | struct hrtimer *timer = &timr->it.real.timer; |
255 | ||
becf8b5d | 256 | if (timr->it.real.interval.tv64 == 0) |
1da177e4 LT |
257 | return; |
258 | ||
44f21475 | 259 | timr->it_overrun += hrtimer_forward(timer, timer->base->get_time(), |
becf8b5d | 260 | timr->it.real.interval); |
44f21475 | 261 | |
1da177e4 LT |
262 | timr->it_overrun_last = timr->it_overrun; |
263 | timr->it_overrun = -1; | |
264 | ++timr->it_requeue_pending; | |
44f21475 | 265 | hrtimer_restart(timer); |
1da177e4 LT |
266 | } |
267 | ||
268 | /* | |
269 | * This function is exported for use by the signal deliver code. It is | |
270 | * called just prior to the info block being released and passes that | |
271 | * block to us. It's function is to update the overrun entry AND to | |
272 | * restart the timer. It should only be called if the timer is to be | |
273 | * restarted (i.e. we have flagged this in the sys_private entry of the | |
274 | * info block). | |
275 | * | |
276 | * To protect aginst the timer going away while the interrupt is queued, | |
277 | * we require that the it_requeue_pending flag be set. | |
278 | */ | |
279 | void do_schedule_next_timer(struct siginfo *info) | |
280 | { | |
281 | struct k_itimer *timr; | |
282 | unsigned long flags; | |
283 | ||
284 | timr = lock_timer(info->si_tid, &flags); | |
285 | ||
becf8b5d TG |
286 | if (timr && timr->it_requeue_pending == info->si_sys_private) { |
287 | if (timr->it_clock < 0) | |
288 | posix_cpu_timer_schedule(timr); | |
289 | else | |
290 | schedule_next_timer(timr); | |
1da177e4 | 291 | |
becf8b5d TG |
292 | info->si_overrun = timr->it_overrun_last; |
293 | } | |
294 | ||
b6557fbc TG |
295 | if (timr) |
296 | unlock_timer(timr, flags); | |
1da177e4 LT |
297 | } |
298 | ||
299 | int posix_timer_event(struct k_itimer *timr,int si_private) | |
300 | { | |
301 | memset(&timr->sigq->info, 0, sizeof(siginfo_t)); | |
302 | timr->sigq->info.si_sys_private = si_private; | |
becf8b5d | 303 | /* Send signal to the process that owns this timer.*/ |
1da177e4 LT |
304 | |
305 | timr->sigq->info.si_signo = timr->it_sigev_signo; | |
306 | timr->sigq->info.si_errno = 0; | |
307 | timr->sigq->info.si_code = SI_TIMER; | |
308 | timr->sigq->info.si_tid = timr->it_id; | |
309 | timr->sigq->info.si_value = timr->it_sigev_value; | |
e752dd6c | 310 | |
1da177e4 | 311 | if (timr->it_sigev_notify & SIGEV_THREAD_ID) { |
e752dd6c ON |
312 | struct task_struct *leader; |
313 | int ret = send_sigqueue(timr->it_sigev_signo, timr->sigq, | |
314 | timr->it_process); | |
315 | ||
316 | if (likely(ret >= 0)) | |
317 | return ret; | |
318 | ||
319 | timr->it_sigev_notify = SIGEV_SIGNAL; | |
320 | leader = timr->it_process->group_leader; | |
321 | put_task_struct(timr->it_process); | |
322 | timr->it_process = leader; | |
1da177e4 | 323 | } |
e752dd6c ON |
324 | |
325 | return send_group_sigqueue(timr->it_sigev_signo, timr->sigq, | |
326 | timr->it_process); | |
1da177e4 LT |
327 | } |
328 | EXPORT_SYMBOL_GPL(posix_timer_event); | |
329 | ||
330 | /* | |
331 | * This function gets called when a POSIX.1b interval timer expires. It | |
332 | * is used as a callback from the kernel internal timer. The | |
333 | * run_timer_list code ALWAYS calls with interrupts on. | |
334 | ||
335 | * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers. | |
336 | */ | |
c9cb2e3d | 337 | static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) |
1da177e4 | 338 | { |
05cfb614 | 339 | struct k_itimer *timr; |
1da177e4 | 340 | unsigned long flags; |
becf8b5d | 341 | int si_private = 0; |
c9cb2e3d | 342 | enum hrtimer_restart ret = HRTIMER_NORESTART; |
1da177e4 | 343 | |
05cfb614 | 344 | timr = container_of(timer, struct k_itimer, it.real.timer); |
1da177e4 | 345 | spin_lock_irqsave(&timr->it_lock, flags); |
1da177e4 | 346 | |
becf8b5d TG |
347 | if (timr->it.real.interval.tv64 != 0) |
348 | si_private = ++timr->it_requeue_pending; | |
1da177e4 | 349 | |
becf8b5d TG |
350 | if (posix_timer_event(timr, si_private)) { |
351 | /* | |
352 | * signal was not sent because of sig_ignor | |
353 | * we will not get a call back to restart it AND | |
354 | * it should be restarted. | |
355 | */ | |
356 | if (timr->it.real.interval.tv64 != 0) { | |
58229a18 TG |
357 | ktime_t now = hrtimer_cb_get_time(timer); |
358 | ||
359 | /* | |
360 | * FIXME: What we really want, is to stop this | |
361 | * timer completely and restart it in case the | |
362 | * SIG_IGN is removed. This is a non trivial | |
363 | * change which involves sighand locking | |
364 | * (sigh !), which we don't want to do late in | |
365 | * the release cycle. | |
366 | * | |
367 | * For now we just let timers with an interval | |
368 | * less than a jiffie expire every jiffie to | |
369 | * avoid softirq starvation in case of SIG_IGN | |
370 | * and a very small interval, which would put | |
371 | * the timer right back on the softirq pending | |
372 | * list. By moving now ahead of time we trick | |
373 | * hrtimer_forward() to expire the timer | |
374 | * later, while we still maintain the overrun | |
375 | * accuracy, but have some inconsistency in | |
376 | * the timer_gettime() case. This is at least | |
377 | * better than a starved softirq. A more | |
378 | * complex fix which solves also another related | |
379 | * inconsistency is already in the pipeline. | |
380 | */ | |
381 | #ifdef CONFIG_HIGH_RES_TIMERS | |
382 | { | |
383 | ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ); | |
384 | ||
385 | if (timr->it.real.interval.tv64 < kj.tv64) | |
386 | now = ktime_add(now, kj); | |
387 | } | |
388 | #endif | |
becf8b5d | 389 | timr->it_overrun += |
58229a18 | 390 | hrtimer_forward(timer, now, |
becf8b5d TG |
391 | timr->it.real.interval); |
392 | ret = HRTIMER_RESTART; | |
a0a0c28c | 393 | ++timr->it_requeue_pending; |
1da177e4 | 394 | } |
1da177e4 | 395 | } |
1da177e4 | 396 | |
becf8b5d TG |
397 | unlock_timer(timr, flags); |
398 | return ret; | |
399 | } | |
1da177e4 | 400 | |
858119e1 | 401 | static struct task_struct * good_sigevent(sigevent_t * event) |
1da177e4 LT |
402 | { |
403 | struct task_struct *rtn = current->group_leader; | |
404 | ||
405 | if ((event->sigev_notify & SIGEV_THREAD_ID ) && | |
406 | (!(rtn = find_task_by_pid(event->sigev_notify_thread_id)) || | |
bac0abd6 | 407 | !same_thread_group(rtn, current) || |
1da177e4 LT |
408 | (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) |
409 | return NULL; | |
410 | ||
411 | if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) && | |
412 | ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX))) | |
413 | return NULL; | |
414 | ||
415 | return rtn; | |
416 | } | |
417 | ||
a924b04d | 418 | void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock) |
1da177e4 LT |
419 | { |
420 | if ((unsigned) clock_id >= MAX_CLOCKS) { | |
421 | printk("POSIX clock register failed for clock_id %d\n", | |
422 | clock_id); | |
423 | return; | |
424 | } | |
425 | ||
426 | posix_clocks[clock_id] = *new_clock; | |
427 | } | |
428 | EXPORT_SYMBOL_GPL(register_posix_clock); | |
429 | ||
430 | static struct k_itimer * alloc_posix_timer(void) | |
431 | { | |
432 | struct k_itimer *tmr; | |
c3762229 | 433 | tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL); |
1da177e4 LT |
434 | if (!tmr) |
435 | return tmr; | |
1da177e4 LT |
436 | if (unlikely(!(tmr->sigq = sigqueue_alloc()))) { |
437 | kmem_cache_free(posix_timers_cache, tmr); | |
438 | tmr = NULL; | |
439 | } | |
440 | return tmr; | |
441 | } | |
442 | ||
443 | #define IT_ID_SET 1 | |
444 | #define IT_ID_NOT_SET 0 | |
445 | static void release_posix_timer(struct k_itimer *tmr, int it_id_set) | |
446 | { | |
447 | if (it_id_set) { | |
448 | unsigned long flags; | |
449 | spin_lock_irqsave(&idr_lock, flags); | |
450 | idr_remove(&posix_timers_id, tmr->it_id); | |
451 | spin_unlock_irqrestore(&idr_lock, flags); | |
452 | } | |
453 | sigqueue_free(tmr->sigq); | |
454 | if (unlikely(tmr->it_process) && | |
455 | tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) | |
456 | put_task_struct(tmr->it_process); | |
457 | kmem_cache_free(posix_timers_cache, tmr); | |
458 | } | |
459 | ||
460 | /* Create a POSIX.1b interval timer. */ | |
461 | ||
462 | asmlinkage long | |
a924b04d | 463 | sys_timer_create(const clockid_t which_clock, |
1da177e4 LT |
464 | struct sigevent __user *timer_event_spec, |
465 | timer_t __user * created_timer_id) | |
466 | { | |
467 | int error = 0; | |
468 | struct k_itimer *new_timer = NULL; | |
469 | int new_timer_id; | |
470 | struct task_struct *process = NULL; | |
471 | unsigned long flags; | |
472 | sigevent_t event; | |
473 | int it_id_set = IT_ID_NOT_SET; | |
474 | ||
475 | if (invalid_clockid(which_clock)) | |
476 | return -EINVAL; | |
477 | ||
478 | new_timer = alloc_posix_timer(); | |
479 | if (unlikely(!new_timer)) | |
480 | return -EAGAIN; | |
481 | ||
482 | spin_lock_init(&new_timer->it_lock); | |
483 | retry: | |
484 | if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) { | |
485 | error = -EAGAIN; | |
486 | goto out; | |
487 | } | |
488 | spin_lock_irq(&idr_lock); | |
becf8b5d | 489 | error = idr_get_new(&posix_timers_id, (void *) new_timer, |
1da177e4 LT |
490 | &new_timer_id); |
491 | spin_unlock_irq(&idr_lock); | |
492 | if (error == -EAGAIN) | |
493 | goto retry; | |
494 | else if (error) { | |
495 | /* | |
496 | * Wierd looking, but we return EAGAIN if the IDR is | |
497 | * full (proper POSIX return value for this) | |
498 | */ | |
499 | error = -EAGAIN; | |
500 | goto out; | |
501 | } | |
502 | ||
503 | it_id_set = IT_ID_SET; | |
504 | new_timer->it_id = (timer_t) new_timer_id; | |
505 | new_timer->it_clock = which_clock; | |
506 | new_timer->it_overrun = -1; | |
507 | error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer)); | |
508 | if (error) | |
509 | goto out; | |
510 | ||
511 | /* | |
512 | * return the timer_id now. The next step is hard to | |
513 | * back out if there is an error. | |
514 | */ | |
515 | if (copy_to_user(created_timer_id, | |
516 | &new_timer_id, sizeof (new_timer_id))) { | |
517 | error = -EFAULT; | |
518 | goto out; | |
519 | } | |
520 | if (timer_event_spec) { | |
521 | if (copy_from_user(&event, timer_event_spec, sizeof (event))) { | |
522 | error = -EFAULT; | |
523 | goto out; | |
524 | } | |
525 | new_timer->it_sigev_notify = event.sigev_notify; | |
526 | new_timer->it_sigev_signo = event.sigev_signo; | |
527 | new_timer->it_sigev_value = event.sigev_value; | |
528 | ||
529 | read_lock(&tasklist_lock); | |
530 | if ((process = good_sigevent(&event))) { | |
531 | /* | |
532 | * We may be setting up this process for another | |
533 | * thread. It may be exiting. To catch this | |
534 | * case the we check the PF_EXITING flag. If | |
535 | * the flag is not set, the siglock will catch | |
536 | * him before it is too late (in exit_itimers). | |
537 | * | |
538 | * The exec case is a bit more invloved but easy | |
539 | * to code. If the process is in our thread | |
540 | * group (and it must be or we would not allow | |
541 | * it here) and is doing an exec, it will cause | |
542 | * us to be killed. In this case it will wait | |
543 | * for us to die which means we can finish this | |
544 | * linkage with our last gasp. I.e. no code :) | |
545 | */ | |
546 | spin_lock_irqsave(&process->sighand->siglock, flags); | |
547 | if (!(process->flags & PF_EXITING)) { | |
548 | new_timer->it_process = process; | |
549 | list_add(&new_timer->list, | |
550 | &process->signal->posix_timers); | |
1da177e4 LT |
551 | if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
552 | get_task_struct(process); | |
d02479bd | 553 | spin_unlock_irqrestore(&process->sighand->siglock, flags); |
1da177e4 LT |
554 | } else { |
555 | spin_unlock_irqrestore(&process->sighand->siglock, flags); | |
556 | process = NULL; | |
557 | } | |
558 | } | |
559 | read_unlock(&tasklist_lock); | |
560 | if (!process) { | |
561 | error = -EINVAL; | |
562 | goto out; | |
563 | } | |
564 | } else { | |
565 | new_timer->it_sigev_notify = SIGEV_SIGNAL; | |
566 | new_timer->it_sigev_signo = SIGALRM; | |
567 | new_timer->it_sigev_value.sival_int = new_timer->it_id; | |
568 | process = current->group_leader; | |
569 | spin_lock_irqsave(&process->sighand->siglock, flags); | |
570 | new_timer->it_process = process; | |
571 | list_add(&new_timer->list, &process->signal->posix_timers); | |
572 | spin_unlock_irqrestore(&process->sighand->siglock, flags); | |
573 | } | |
574 | ||
575 | /* | |
576 | * In the case of the timer belonging to another task, after | |
577 | * the task is unlocked, the timer is owned by the other task | |
578 | * and may cease to exist at any time. Don't use or modify | |
579 | * new_timer after the unlock call. | |
580 | */ | |
581 | ||
582 | out: | |
583 | if (error) | |
584 | release_posix_timer(new_timer, it_id_set); | |
585 | ||
586 | return error; | |
587 | } | |
588 | ||
1da177e4 LT |
589 | /* |
590 | * Locking issues: We need to protect the result of the id look up until | |
591 | * we get the timer locked down so it is not deleted under us. The | |
592 | * removal is done under the idr spinlock so we use that here to bridge | |
593 | * the find to the timer lock. To avoid a dead lock, the timer id MUST | |
594 | * be release with out holding the timer lock. | |
595 | */ | |
596 | static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) | |
597 | { | |
598 | struct k_itimer *timr; | |
599 | /* | |
600 | * Watch out here. We do a irqsave on the idr_lock and pass the | |
601 | * flags part over to the timer lock. Must not let interrupts in | |
602 | * while we are moving the lock. | |
603 | */ | |
604 | ||
605 | spin_lock_irqsave(&idr_lock, *flags); | |
606 | timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id); | |
607 | if (timr) { | |
608 | spin_lock(&timr->it_lock); | |
1da177e4 LT |
609 | |
610 | if ((timr->it_id != timer_id) || !(timr->it_process) || | |
bac0abd6 | 611 | !same_thread_group(timr->it_process, current)) { |
179394af TG |
612 | spin_unlock(&timr->it_lock); |
613 | spin_unlock_irqrestore(&idr_lock, *flags); | |
1da177e4 | 614 | timr = NULL; |
179394af TG |
615 | } else |
616 | spin_unlock(&idr_lock); | |
1da177e4 LT |
617 | } else |
618 | spin_unlock_irqrestore(&idr_lock, *flags); | |
619 | ||
620 | return timr; | |
621 | } | |
622 | ||
623 | /* | |
624 | * Get the time remaining on a POSIX.1b interval timer. This function | |
625 | * is ALWAYS called with spin_lock_irq on the timer, thus it must not | |
626 | * mess with irq. | |
627 | * | |
628 | * We have a couple of messes to clean up here. First there is the case | |
629 | * of a timer that has a requeue pending. These timers should appear to | |
630 | * be in the timer list with an expiry as if we were to requeue them | |
631 | * now. | |
632 | * | |
633 | * The second issue is the SIGEV_NONE timer which may be active but is | |
634 | * not really ever put in the timer list (to save system resources). | |
635 | * This timer may be expired, and if so, we will do it here. Otherwise | |
636 | * it is the same as a requeue pending timer WRT to what we should | |
637 | * report. | |
638 | */ | |
639 | static void | |
640 | common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) | |
641 | { | |
3b98a532 | 642 | ktime_t now, remaining, iv; |
becf8b5d | 643 | struct hrtimer *timer = &timr->it.real.timer; |
1da177e4 | 644 | |
becf8b5d | 645 | memset(cur_setting, 0, sizeof(struct itimerspec)); |
becf8b5d | 646 | |
3b98a532 RZ |
647 | iv = timr->it.real.interval; |
648 | ||
becf8b5d | 649 | /* interval timer ? */ |
3b98a532 RZ |
650 | if (iv.tv64) |
651 | cur_setting->it_interval = ktime_to_timespec(iv); | |
652 | else if (!hrtimer_active(timer) && | |
653 | (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) | |
becf8b5d | 654 | return; |
3b98a532 RZ |
655 | |
656 | now = timer->base->get_time(); | |
657 | ||
becf8b5d | 658 | /* |
3b98a532 RZ |
659 | * When a requeue is pending or this is a SIGEV_NONE |
660 | * timer move the expiry time forward by intervals, so | |
661 | * expiry is > now. | |
becf8b5d | 662 | */ |
3b98a532 RZ |
663 | if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING || |
664 | (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) | |
665 | timr->it_overrun += hrtimer_forward(timer, now, iv); | |
666 | ||
667 | remaining = ktime_sub(timer->expires, now); | |
becf8b5d | 668 | /* Return 0 only, when the timer is expired and not pending */ |
3b98a532 RZ |
669 | if (remaining.tv64 <= 0) { |
670 | /* | |
671 | * A single shot SIGEV_NONE timer must return 0, when | |
672 | * it is expired ! | |
673 | */ | |
674 | if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) | |
675 | cur_setting->it_value.tv_nsec = 1; | |
676 | } else | |
becf8b5d | 677 | cur_setting->it_value = ktime_to_timespec(remaining); |
1da177e4 LT |
678 | } |
679 | ||
680 | /* Get the time remaining on a POSIX.1b interval timer. */ | |
681 | asmlinkage long | |
682 | sys_timer_gettime(timer_t timer_id, struct itimerspec __user *setting) | |
683 | { | |
684 | struct k_itimer *timr; | |
685 | struct itimerspec cur_setting; | |
686 | unsigned long flags; | |
687 | ||
688 | timr = lock_timer(timer_id, &flags); | |
689 | if (!timr) | |
690 | return -EINVAL; | |
691 | ||
692 | CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting)); | |
693 | ||
694 | unlock_timer(timr, flags); | |
695 | ||
696 | if (copy_to_user(setting, &cur_setting, sizeof (cur_setting))) | |
697 | return -EFAULT; | |
698 | ||
699 | return 0; | |
700 | } | |
becf8b5d | 701 | |
1da177e4 LT |
702 | /* |
703 | * Get the number of overruns of a POSIX.1b interval timer. This is to | |
704 | * be the overrun of the timer last delivered. At the same time we are | |
705 | * accumulating overruns on the next timer. The overrun is frozen when | |
706 | * the signal is delivered, either at the notify time (if the info block | |
707 | * is not queued) or at the actual delivery time (as we are informed by | |
708 | * the call back to do_schedule_next_timer(). So all we need to do is | |
709 | * to pick up the frozen overrun. | |
710 | */ | |
1da177e4 LT |
711 | asmlinkage long |
712 | sys_timer_getoverrun(timer_t timer_id) | |
713 | { | |
714 | struct k_itimer *timr; | |
715 | int overrun; | |
5ba25331 | 716 | unsigned long flags; |
1da177e4 LT |
717 | |
718 | timr = lock_timer(timer_id, &flags); | |
719 | if (!timr) | |
720 | return -EINVAL; | |
721 | ||
722 | overrun = timr->it_overrun_last; | |
723 | unlock_timer(timr, flags); | |
724 | ||
725 | return overrun; | |
726 | } | |
1da177e4 LT |
727 | |
728 | /* Set a POSIX.1b interval timer. */ | |
729 | /* timr->it_lock is taken. */ | |
858119e1 | 730 | static int |
1da177e4 LT |
731 | common_timer_set(struct k_itimer *timr, int flags, |
732 | struct itimerspec *new_setting, struct itimerspec *old_setting) | |
733 | { | |
becf8b5d | 734 | struct hrtimer *timer = &timr->it.real.timer; |
7978672c | 735 | enum hrtimer_mode mode; |
1da177e4 LT |
736 | |
737 | if (old_setting) | |
738 | common_timer_get(timr, old_setting); | |
739 | ||
740 | /* disable the timer */ | |
becf8b5d | 741 | timr->it.real.interval.tv64 = 0; |
1da177e4 LT |
742 | /* |
743 | * careful here. If smp we could be in the "fire" routine which will | |
744 | * be spinning as we hold the lock. But this is ONLY an SMP issue. | |
745 | */ | |
becf8b5d | 746 | if (hrtimer_try_to_cancel(timer) < 0) |
1da177e4 | 747 | return TIMER_RETRY; |
1da177e4 LT |
748 | |
749 | timr->it_requeue_pending = (timr->it_requeue_pending + 2) & | |
750 | ~REQUEUE_PENDING; | |
751 | timr->it_overrun_last = 0; | |
1da177e4 | 752 | |
becf8b5d TG |
753 | /* switch off the timer when it_value is zero */ |
754 | if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) | |
755 | return 0; | |
1da177e4 | 756 | |
c9cb2e3d | 757 | mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; |
7978672c | 758 | hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); |
7978672c | 759 | timr->it.real.timer.function = posix_timer_fn; |
becf8b5d TG |
760 | |
761 | timer->expires = timespec_to_ktime(new_setting->it_value); | |
762 | ||
763 | /* Convert interval */ | |
764 | timr->it.real.interval = timespec_to_ktime(new_setting->it_interval); | |
765 | ||
766 | /* SIGEV_NONE timers are not queued ! See common_timer_get */ | |
952bbc87 TG |
767 | if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) { |
768 | /* Setup correct expiry time for relative timers */ | |
c9cb2e3d | 769 | if (mode == HRTIMER_MODE_REL) |
952bbc87 TG |
770 | timer->expires = ktime_add(timer->expires, |
771 | timer->base->get_time()); | |
becf8b5d | 772 | return 0; |
952bbc87 | 773 | } |
becf8b5d | 774 | |
7978672c | 775 | hrtimer_start(timer, timer->expires, mode); |
1da177e4 LT |
776 | return 0; |
777 | } | |
778 | ||
779 | /* Set a POSIX.1b interval timer */ | |
780 | asmlinkage long | |
781 | sys_timer_settime(timer_t timer_id, int flags, | |
782 | const struct itimerspec __user *new_setting, | |
783 | struct itimerspec __user *old_setting) | |
784 | { | |
785 | struct k_itimer *timr; | |
786 | struct itimerspec new_spec, old_spec; | |
787 | int error = 0; | |
5ba25331 | 788 | unsigned long flag; |
1da177e4 LT |
789 | struct itimerspec *rtn = old_setting ? &old_spec : NULL; |
790 | ||
791 | if (!new_setting) | |
792 | return -EINVAL; | |
793 | ||
794 | if (copy_from_user(&new_spec, new_setting, sizeof (new_spec))) | |
795 | return -EFAULT; | |
796 | ||
becf8b5d TG |
797 | if (!timespec_valid(&new_spec.it_interval) || |
798 | !timespec_valid(&new_spec.it_value)) | |
1da177e4 LT |
799 | return -EINVAL; |
800 | retry: | |
801 | timr = lock_timer(timer_id, &flag); | |
802 | if (!timr) | |
803 | return -EINVAL; | |
804 | ||
805 | error = CLOCK_DISPATCH(timr->it_clock, timer_set, | |
806 | (timr, flags, &new_spec, rtn)); | |
807 | ||
808 | unlock_timer(timr, flag); | |
809 | if (error == TIMER_RETRY) { | |
810 | rtn = NULL; // We already got the old time... | |
811 | goto retry; | |
812 | } | |
813 | ||
becf8b5d TG |
814 | if (old_setting && !error && |
815 | copy_to_user(old_setting, &old_spec, sizeof (old_spec))) | |
1da177e4 LT |
816 | error = -EFAULT; |
817 | ||
818 | return error; | |
819 | } | |
820 | ||
821 | static inline int common_timer_del(struct k_itimer *timer) | |
822 | { | |
becf8b5d | 823 | timer->it.real.interval.tv64 = 0; |
f972be33 | 824 | |
becf8b5d | 825 | if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0) |
1da177e4 | 826 | return TIMER_RETRY; |
1da177e4 LT |
827 | return 0; |
828 | } | |
829 | ||
830 | static inline int timer_delete_hook(struct k_itimer *timer) | |
831 | { | |
832 | return CLOCK_DISPATCH(timer->it_clock, timer_del, (timer)); | |
833 | } | |
834 | ||
835 | /* Delete a POSIX.1b interval timer. */ | |
836 | asmlinkage long | |
837 | sys_timer_delete(timer_t timer_id) | |
838 | { | |
839 | struct k_itimer *timer; | |
5ba25331 | 840 | unsigned long flags; |
1da177e4 | 841 | |
1da177e4 | 842 | retry_delete: |
1da177e4 LT |
843 | timer = lock_timer(timer_id, &flags); |
844 | if (!timer) | |
845 | return -EINVAL; | |
846 | ||
becf8b5d | 847 | if (timer_delete_hook(timer) == TIMER_RETRY) { |
1da177e4 LT |
848 | unlock_timer(timer, flags); |
849 | goto retry_delete; | |
850 | } | |
becf8b5d | 851 | |
1da177e4 LT |
852 | spin_lock(¤t->sighand->siglock); |
853 | list_del(&timer->list); | |
854 | spin_unlock(¤t->sighand->siglock); | |
855 | /* | |
856 | * This keeps any tasks waiting on the spin lock from thinking | |
857 | * they got something (see the lock code above). | |
858 | */ | |
859 | if (timer->it_process) { | |
860 | if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) | |
861 | put_task_struct(timer->it_process); | |
862 | timer->it_process = NULL; | |
863 | } | |
864 | unlock_timer(timer, flags); | |
865 | release_posix_timer(timer, IT_ID_SET); | |
866 | return 0; | |
867 | } | |
becf8b5d | 868 | |
1da177e4 LT |
869 | /* |
870 | * return timer owned by the process, used by exit_itimers | |
871 | */ | |
858119e1 | 872 | static void itimer_delete(struct k_itimer *timer) |
1da177e4 LT |
873 | { |
874 | unsigned long flags; | |
875 | ||
1da177e4 | 876 | retry_delete: |
1da177e4 LT |
877 | spin_lock_irqsave(&timer->it_lock, flags); |
878 | ||
becf8b5d | 879 | if (timer_delete_hook(timer) == TIMER_RETRY) { |
1da177e4 LT |
880 | unlock_timer(timer, flags); |
881 | goto retry_delete; | |
882 | } | |
1da177e4 LT |
883 | list_del(&timer->list); |
884 | /* | |
885 | * This keeps any tasks waiting on the spin lock from thinking | |
886 | * they got something (see the lock code above). | |
887 | */ | |
888 | if (timer->it_process) { | |
889 | if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) | |
890 | put_task_struct(timer->it_process); | |
891 | timer->it_process = NULL; | |
892 | } | |
893 | unlock_timer(timer, flags); | |
894 | release_posix_timer(timer, IT_ID_SET); | |
895 | } | |
896 | ||
897 | /* | |
25f407f0 | 898 | * This is called by do_exit or de_thread, only when there are no more |
1da177e4 LT |
899 | * references to the shared signal_struct. |
900 | */ | |
901 | void exit_itimers(struct signal_struct *sig) | |
902 | { | |
903 | struct k_itimer *tmr; | |
904 | ||
905 | while (!list_empty(&sig->posix_timers)) { | |
906 | tmr = list_entry(sig->posix_timers.next, struct k_itimer, list); | |
907 | itimer_delete(tmr); | |
908 | } | |
909 | } | |
910 | ||
becf8b5d | 911 | /* Not available / possible... functions */ |
a924b04d | 912 | int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp) |
1da177e4 LT |
913 | { |
914 | return -EINVAL; | |
915 | } | |
916 | EXPORT_SYMBOL_GPL(do_posix_clock_nosettime); | |
917 | ||
a924b04d | 918 | int do_posix_clock_nonanosleep(const clockid_t clock, int flags, |
97735f25 | 919 | struct timespec *t, struct timespec __user *r) |
1da177e4 LT |
920 | { |
921 | #ifndef ENOTSUP | |
922 | return -EOPNOTSUPP; /* aka ENOTSUP in userland for POSIX */ | |
923 | #else /* parisc does define it separately. */ | |
924 | return -ENOTSUP; | |
925 | #endif | |
926 | } | |
927 | EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep); | |
928 | ||
a924b04d TG |
929 | asmlinkage long sys_clock_settime(const clockid_t which_clock, |
930 | const struct timespec __user *tp) | |
1da177e4 LT |
931 | { |
932 | struct timespec new_tp; | |
933 | ||
934 | if (invalid_clockid(which_clock)) | |
935 | return -EINVAL; | |
936 | if (copy_from_user(&new_tp, tp, sizeof (*tp))) | |
937 | return -EFAULT; | |
938 | ||
939 | return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp)); | |
940 | } | |
941 | ||
942 | asmlinkage long | |
a924b04d | 943 | sys_clock_gettime(const clockid_t which_clock, struct timespec __user *tp) |
1da177e4 LT |
944 | { |
945 | struct timespec kernel_tp; | |
946 | int error; | |
947 | ||
948 | if (invalid_clockid(which_clock)) | |
949 | return -EINVAL; | |
950 | error = CLOCK_DISPATCH(which_clock, clock_get, | |
951 | (which_clock, &kernel_tp)); | |
952 | if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp))) | |
953 | error = -EFAULT; | |
954 | ||
955 | return error; | |
956 | ||
957 | } | |
958 | ||
959 | asmlinkage long | |
a924b04d | 960 | sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp) |
1da177e4 LT |
961 | { |
962 | struct timespec rtn_tp; | |
963 | int error; | |
964 | ||
965 | if (invalid_clockid(which_clock)) | |
966 | return -EINVAL; | |
967 | ||
968 | error = CLOCK_DISPATCH(which_clock, clock_getres, | |
969 | (which_clock, &rtn_tp)); | |
970 | ||
971 | if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp))) { | |
972 | error = -EFAULT; | |
973 | } | |
974 | ||
975 | return error; | |
976 | } | |
977 | ||
97735f25 TG |
978 | /* |
979 | * nanosleep for monotonic and realtime clocks | |
980 | */ | |
981 | static int common_nsleep(const clockid_t which_clock, int flags, | |
982 | struct timespec *tsave, struct timespec __user *rmtp) | |
983 | { | |
04c22714 AB |
984 | struct timespec rmt; |
985 | int ret; | |
986 | ||
987 | ret = hrtimer_nanosleep(tsave, rmtp ? &rmt : NULL, | |
988 | flags & TIMER_ABSTIME ? | |
989 | HRTIMER_MODE_ABS : HRTIMER_MODE_REL, | |
990 | which_clock); | |
991 | ||
992 | if (ret && rmtp) { | |
993 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
994 | return -EFAULT; | |
995 | } | |
996 | ||
997 | return ret; | |
97735f25 | 998 | } |
1da177e4 LT |
999 | |
1000 | asmlinkage long | |
a924b04d | 1001 | sys_clock_nanosleep(const clockid_t which_clock, int flags, |
1da177e4 LT |
1002 | const struct timespec __user *rqtp, |
1003 | struct timespec __user *rmtp) | |
1004 | { | |
1005 | struct timespec t; | |
1da177e4 LT |
1006 | |
1007 | if (invalid_clockid(which_clock)) | |
1008 | return -EINVAL; | |
1009 | ||
1010 | if (copy_from_user(&t, rqtp, sizeof (struct timespec))) | |
1011 | return -EFAULT; | |
1012 | ||
5f82b2b7 | 1013 | if (!timespec_valid(&t)) |
1da177e4 LT |
1014 | return -EINVAL; |
1015 | ||
97735f25 TG |
1016 | return CLOCK_DISPATCH(which_clock, nsleep, |
1017 | (which_clock, flags, &t, rmtp)); | |
1da177e4 | 1018 | } |
1711ef38 TA |
1019 | |
1020 | /* | |
1021 | * nanosleep_restart for monotonic and realtime clocks | |
1022 | */ | |
1023 | static int common_nsleep_restart(struct restart_block *restart_block) | |
1024 | { | |
1025 | return hrtimer_nanosleep_restart(restart_block); | |
1026 | } | |
1027 | ||
1028 | /* | |
1029 | * This will restart clock_nanosleep. This is required only by | |
1030 | * compat_clock_nanosleep_restart for now. | |
1031 | */ | |
1032 | long | |
1033 | clock_nanosleep_restart(struct restart_block *restart_block) | |
1034 | { | |
1035 | clockid_t which_clock = restart_block->arg0; | |
1036 | ||
1037 | return CLOCK_DISPATCH(which_clock, nsleep_restart, | |
1038 | (restart_block)); | |
1039 | } |