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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Implement CPU time clocks for the POSIX clock interface. | |
3 | */ | |
4 | ||
5 | #include <linux/sched.h> | |
6 | #include <linux/posix-timers.h> | |
1da177e4 | 7 | #include <linux/errno.h> |
f8bd2258 RZ |
8 | #include <linux/math64.h> |
9 | #include <asm/uaccess.h> | |
bb34d92f | 10 | #include <linux/kernel_stat.h> |
3f0a525e | 11 | #include <trace/events/timer.h> |
61337054 | 12 | #include <linux/random.h> |
a8572160 FW |
13 | #include <linux/tick.h> |
14 | #include <linux/workqueue.h> | |
1da177e4 | 15 | |
f06febc9 | 16 | /* |
f55db609 SG |
17 | * Called after updating RLIMIT_CPU to run cpu timer and update |
18 | * tsk->signal->cputime_expires expiration cache if necessary. Needs | |
19 | * siglock protection since other code may update expiration cache as | |
20 | * well. | |
f06febc9 | 21 | */ |
5ab46b34 | 22 | void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new) |
f06febc9 | 23 | { |
42c4ab41 | 24 | cputime_t cputime = secs_to_cputime(rlim_new); |
f06febc9 | 25 | |
5ab46b34 JS |
26 | spin_lock_irq(&task->sighand->siglock); |
27 | set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL); | |
28 | spin_unlock_irq(&task->sighand->siglock); | |
f06febc9 FM |
29 | } |
30 | ||
a924b04d | 31 | static int check_clock(const clockid_t which_clock) |
1da177e4 LT |
32 | { |
33 | int error = 0; | |
34 | struct task_struct *p; | |
35 | const pid_t pid = CPUCLOCK_PID(which_clock); | |
36 | ||
37 | if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX) | |
38 | return -EINVAL; | |
39 | ||
40 | if (pid == 0) | |
41 | return 0; | |
42 | ||
c0deae8c | 43 | rcu_read_lock(); |
8dc86af0 | 44 | p = find_task_by_vpid(pid); |
bac0abd6 | 45 | if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ? |
c0deae8c | 46 | same_thread_group(p, current) : has_group_leader_pid(p))) { |
1da177e4 LT |
47 | error = -EINVAL; |
48 | } | |
c0deae8c | 49 | rcu_read_unlock(); |
1da177e4 LT |
50 | |
51 | return error; | |
52 | } | |
53 | ||
55ccb616 | 54 | static inline unsigned long long |
a924b04d | 55 | timespec_to_sample(const clockid_t which_clock, const struct timespec *tp) |
1da177e4 | 56 | { |
55ccb616 FW |
57 | unsigned long long ret; |
58 | ||
59 | ret = 0; /* high half always zero when .cpu used */ | |
1da177e4 | 60 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
55ccb616 | 61 | ret = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec; |
1da177e4 | 62 | } else { |
55ccb616 | 63 | ret = cputime_to_expires(timespec_to_cputime(tp)); |
1da177e4 LT |
64 | } |
65 | return ret; | |
66 | } | |
67 | ||
a924b04d | 68 | static void sample_to_timespec(const clockid_t which_clock, |
55ccb616 | 69 | unsigned long long expires, |
1da177e4 LT |
70 | struct timespec *tp) |
71 | { | |
f8bd2258 | 72 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) |
55ccb616 | 73 | *tp = ns_to_timespec(expires); |
f8bd2258 | 74 | else |
55ccb616 | 75 | cputime_to_timespec((__force cputime_t)expires, tp); |
1da177e4 LT |
76 | } |
77 | ||
78 | /* | |
79 | * Update expiry time from increment, and increase overrun count, | |
80 | * given the current clock sample. | |
81 | */ | |
7a4ed937 | 82 | static void bump_cpu_timer(struct k_itimer *timer, |
55ccb616 | 83 | unsigned long long now) |
1da177e4 LT |
84 | { |
85 | int i; | |
55ccb616 | 86 | unsigned long long delta, incr; |
1da177e4 | 87 | |
55ccb616 | 88 | if (timer->it.cpu.incr == 0) |
1da177e4 LT |
89 | return; |
90 | ||
55ccb616 FW |
91 | if (now < timer->it.cpu.expires) |
92 | return; | |
1da177e4 | 93 | |
55ccb616 FW |
94 | incr = timer->it.cpu.incr; |
95 | delta = now + incr - timer->it.cpu.expires; | |
1da177e4 | 96 | |
55ccb616 FW |
97 | /* Don't use (incr*2 < delta), incr*2 might overflow. */ |
98 | for (i = 0; incr < delta - incr; i++) | |
99 | incr = incr << 1; | |
100 | ||
101 | for (; i >= 0; incr >>= 1, i--) { | |
102 | if (delta < incr) | |
103 | continue; | |
104 | ||
105 | timer->it.cpu.expires += incr; | |
106 | timer->it_overrun += 1 << i; | |
107 | delta -= incr; | |
1da177e4 LT |
108 | } |
109 | } | |
110 | ||
555347f6 FW |
111 | /** |
112 | * task_cputime_zero - Check a task_cputime struct for all zero fields. | |
113 | * | |
114 | * @cputime: The struct to compare. | |
115 | * | |
116 | * Checks @cputime to see if all fields are zero. Returns true if all fields | |
117 | * are zero, false if any field is nonzero. | |
118 | */ | |
119 | static inline int task_cputime_zero(const struct task_cputime *cputime) | |
120 | { | |
121 | if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) | |
122 | return 1; | |
123 | return 0; | |
124 | } | |
125 | ||
55ccb616 | 126 | static inline unsigned long long prof_ticks(struct task_struct *p) |
1da177e4 | 127 | { |
6fac4829 FW |
128 | cputime_t utime, stime; |
129 | ||
130 | task_cputime(p, &utime, &stime); | |
131 | ||
55ccb616 | 132 | return cputime_to_expires(utime + stime); |
1da177e4 | 133 | } |
55ccb616 | 134 | static inline unsigned long long virt_ticks(struct task_struct *p) |
1da177e4 | 135 | { |
6fac4829 FW |
136 | cputime_t utime; |
137 | ||
138 | task_cputime(p, &utime, NULL); | |
139 | ||
55ccb616 | 140 | return cputime_to_expires(utime); |
1da177e4 | 141 | } |
1da177e4 | 142 | |
bc2c8ea4 TG |
143 | static int |
144 | posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) | |
1da177e4 LT |
145 | { |
146 | int error = check_clock(which_clock); | |
147 | if (!error) { | |
148 | tp->tv_sec = 0; | |
149 | tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ); | |
150 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { | |
151 | /* | |
152 | * If sched_clock is using a cycle counter, we | |
153 | * don't have any idea of its true resolution | |
154 | * exported, but it is much more than 1s/HZ. | |
155 | */ | |
156 | tp->tv_nsec = 1; | |
157 | } | |
158 | } | |
159 | return error; | |
160 | } | |
161 | ||
bc2c8ea4 TG |
162 | static int |
163 | posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) | |
1da177e4 LT |
164 | { |
165 | /* | |
166 | * You can never reset a CPU clock, but we check for other errors | |
167 | * in the call before failing with EPERM. | |
168 | */ | |
169 | int error = check_clock(which_clock); | |
170 | if (error == 0) { | |
171 | error = -EPERM; | |
172 | } | |
173 | return error; | |
174 | } | |
175 | ||
176 | ||
177 | /* | |
178 | * Sample a per-thread clock for the given task. | |
179 | */ | |
a924b04d | 180 | static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, |
55ccb616 | 181 | unsigned long long *sample) |
1da177e4 LT |
182 | { |
183 | switch (CPUCLOCK_WHICH(which_clock)) { | |
184 | default: | |
185 | return -EINVAL; | |
186 | case CPUCLOCK_PROF: | |
55ccb616 | 187 | *sample = prof_ticks(p); |
1da177e4 LT |
188 | break; |
189 | case CPUCLOCK_VIRT: | |
55ccb616 | 190 | *sample = virt_ticks(p); |
1da177e4 LT |
191 | break; |
192 | case CPUCLOCK_SCHED: | |
55ccb616 | 193 | *sample = task_sched_runtime(p); |
1da177e4 LT |
194 | break; |
195 | } | |
196 | return 0; | |
197 | } | |
198 | ||
1018016c JL |
199 | /* |
200 | * Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg | |
201 | * to avoid race conditions with concurrent updates to cputime. | |
202 | */ | |
203 | static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime) | |
4da94d49 | 204 | { |
1018016c JL |
205 | u64 curr_cputime; |
206 | retry: | |
207 | curr_cputime = atomic64_read(cputime); | |
208 | if (sum_cputime > curr_cputime) { | |
209 | if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime) | |
210 | goto retry; | |
211 | } | |
212 | } | |
4da94d49 | 213 | |
71107445 | 214 | static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum) |
1018016c | 215 | { |
71107445 JL |
216 | __update_gt_cputime(&cputime_atomic->utime, sum->utime); |
217 | __update_gt_cputime(&cputime_atomic->stime, sum->stime); | |
218 | __update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime); | |
1018016c | 219 | } |
4da94d49 | 220 | |
71107445 JL |
221 | /* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */ |
222 | static inline void sample_cputime_atomic(struct task_cputime *times, | |
223 | struct task_cputime_atomic *atomic_times) | |
1018016c | 224 | { |
71107445 JL |
225 | times->utime = atomic64_read(&atomic_times->utime); |
226 | times->stime = atomic64_read(&atomic_times->stime); | |
227 | times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime); | |
4da94d49 PZ |
228 | } |
229 | ||
230 | void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) | |
231 | { | |
232 | struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; | |
233 | struct task_cputime sum; | |
4da94d49 | 234 | |
1018016c JL |
235 | /* Check if cputimer isn't running. This is accessed without locking. */ |
236 | if (!READ_ONCE(cputimer->running)) { | |
4da94d49 PZ |
237 | /* |
238 | * The POSIX timer interface allows for absolute time expiry | |
239 | * values through the TIMER_ABSTIME flag, therefore we have | |
1018016c | 240 | * to synchronize the timer to the clock every time we start it. |
4da94d49 PZ |
241 | */ |
242 | thread_group_cputime(tsk, &sum); | |
71107445 | 243 | update_gt_cputime(&cputimer->cputime_atomic, &sum); |
1018016c JL |
244 | |
245 | /* | |
246 | * We're setting cputimer->running without a lock. Ensure | |
247 | * this only gets written to in one operation. We set | |
248 | * running after update_gt_cputime() as a small optimization, | |
249 | * but barriers are not required because update_gt_cputime() | |
250 | * can handle concurrent updates. | |
251 | */ | |
d5c373eb | 252 | WRITE_ONCE(cputimer->running, true); |
1018016c | 253 | } |
71107445 | 254 | sample_cputime_atomic(times, &cputimer->cputime_atomic); |
4da94d49 PZ |
255 | } |
256 | ||
1da177e4 LT |
257 | /* |
258 | * Sample a process (thread group) clock for the given group_leader task. | |
e73d84e3 FW |
259 | * Must be called with task sighand lock held for safe while_each_thread() |
260 | * traversal. | |
1da177e4 | 261 | */ |
bb34d92f FM |
262 | static int cpu_clock_sample_group(const clockid_t which_clock, |
263 | struct task_struct *p, | |
55ccb616 | 264 | unsigned long long *sample) |
1da177e4 | 265 | { |
f06febc9 FM |
266 | struct task_cputime cputime; |
267 | ||
eccdaeaf | 268 | switch (CPUCLOCK_WHICH(which_clock)) { |
1da177e4 LT |
269 | default: |
270 | return -EINVAL; | |
271 | case CPUCLOCK_PROF: | |
c5f8d995 | 272 | thread_group_cputime(p, &cputime); |
55ccb616 | 273 | *sample = cputime_to_expires(cputime.utime + cputime.stime); |
1da177e4 LT |
274 | break; |
275 | case CPUCLOCK_VIRT: | |
c5f8d995 | 276 | thread_group_cputime(p, &cputime); |
55ccb616 | 277 | *sample = cputime_to_expires(cputime.utime); |
1da177e4 LT |
278 | break; |
279 | case CPUCLOCK_SCHED: | |
d670ec13 | 280 | thread_group_cputime(p, &cputime); |
55ccb616 | 281 | *sample = cputime.sum_exec_runtime; |
1da177e4 LT |
282 | break; |
283 | } | |
284 | return 0; | |
285 | } | |
286 | ||
33ab0fec FW |
287 | static int posix_cpu_clock_get_task(struct task_struct *tsk, |
288 | const clockid_t which_clock, | |
289 | struct timespec *tp) | |
290 | { | |
291 | int err = -EINVAL; | |
292 | unsigned long long rtn; | |
293 | ||
294 | if (CPUCLOCK_PERTHREAD(which_clock)) { | |
295 | if (same_thread_group(tsk, current)) | |
296 | err = cpu_clock_sample(which_clock, tsk, &rtn); | |
297 | } else { | |
50875788 | 298 | if (tsk == current || thread_group_leader(tsk)) |
33ab0fec | 299 | err = cpu_clock_sample_group(which_clock, tsk, &rtn); |
33ab0fec FW |
300 | } |
301 | ||
302 | if (!err) | |
303 | sample_to_timespec(which_clock, rtn, tp); | |
304 | ||
305 | return err; | |
306 | } | |
307 | ||
1da177e4 | 308 | |
bc2c8ea4 | 309 | static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) |
1da177e4 LT |
310 | { |
311 | const pid_t pid = CPUCLOCK_PID(which_clock); | |
33ab0fec | 312 | int err = -EINVAL; |
1da177e4 LT |
313 | |
314 | if (pid == 0) { | |
315 | /* | |
316 | * Special case constant value for our own clocks. | |
317 | * We don't have to do any lookup to find ourselves. | |
318 | */ | |
33ab0fec | 319 | err = posix_cpu_clock_get_task(current, which_clock, tp); |
1da177e4 LT |
320 | } else { |
321 | /* | |
322 | * Find the given PID, and validate that the caller | |
323 | * should be able to see it. | |
324 | */ | |
325 | struct task_struct *p; | |
1f2ea083 | 326 | rcu_read_lock(); |
8dc86af0 | 327 | p = find_task_by_vpid(pid); |
33ab0fec FW |
328 | if (p) |
329 | err = posix_cpu_clock_get_task(p, which_clock, tp); | |
1f2ea083 | 330 | rcu_read_unlock(); |
1da177e4 LT |
331 | } |
332 | ||
33ab0fec | 333 | return err; |
1da177e4 LT |
334 | } |
335 | ||
1da177e4 LT |
336 | /* |
337 | * Validate the clockid_t for a new CPU-clock timer, and initialize the timer. | |
ba5ea951 SG |
338 | * This is called from sys_timer_create() and do_cpu_nanosleep() with the |
339 | * new timer already all-zeros initialized. | |
1da177e4 | 340 | */ |
bc2c8ea4 | 341 | static int posix_cpu_timer_create(struct k_itimer *new_timer) |
1da177e4 LT |
342 | { |
343 | int ret = 0; | |
344 | const pid_t pid = CPUCLOCK_PID(new_timer->it_clock); | |
345 | struct task_struct *p; | |
346 | ||
347 | if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX) | |
348 | return -EINVAL; | |
349 | ||
350 | INIT_LIST_HEAD(&new_timer->it.cpu.entry); | |
1da177e4 | 351 | |
c0deae8c | 352 | rcu_read_lock(); |
1da177e4 LT |
353 | if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { |
354 | if (pid == 0) { | |
355 | p = current; | |
356 | } else { | |
8dc86af0 | 357 | p = find_task_by_vpid(pid); |
bac0abd6 | 358 | if (p && !same_thread_group(p, current)) |
1da177e4 LT |
359 | p = NULL; |
360 | } | |
361 | } else { | |
362 | if (pid == 0) { | |
363 | p = current->group_leader; | |
364 | } else { | |
8dc86af0 | 365 | p = find_task_by_vpid(pid); |
c0deae8c | 366 | if (p && !has_group_leader_pid(p)) |
1da177e4 LT |
367 | p = NULL; |
368 | } | |
369 | } | |
370 | new_timer->it.cpu.task = p; | |
371 | if (p) { | |
372 | get_task_struct(p); | |
373 | } else { | |
374 | ret = -EINVAL; | |
375 | } | |
c0deae8c | 376 | rcu_read_unlock(); |
1da177e4 LT |
377 | |
378 | return ret; | |
379 | } | |
380 | ||
381 | /* | |
382 | * Clean up a CPU-clock timer that is about to be destroyed. | |
383 | * This is called from timer deletion with the timer already locked. | |
384 | * If we return TIMER_RETRY, it's necessary to release the timer's lock | |
385 | * and try again. (This happens when the timer is in the middle of firing.) | |
386 | */ | |
bc2c8ea4 | 387 | static int posix_cpu_timer_del(struct k_itimer *timer) |
1da177e4 | 388 | { |
108150ea | 389 | int ret = 0; |
3d7a1427 FW |
390 | unsigned long flags; |
391 | struct sighand_struct *sighand; | |
392 | struct task_struct *p = timer->it.cpu.task; | |
1da177e4 | 393 | |
a3222f88 | 394 | WARN_ON_ONCE(p == NULL); |
108150ea | 395 | |
3d7a1427 FW |
396 | /* |
397 | * Protect against sighand release/switch in exit/exec and process/ | |
398 | * thread timer list entry concurrent read/writes. | |
399 | */ | |
400 | sighand = lock_task_sighand(p, &flags); | |
401 | if (unlikely(sighand == NULL)) { | |
a3222f88 FW |
402 | /* |
403 | * We raced with the reaping of the task. | |
404 | * The deletion should have cleared us off the list. | |
405 | */ | |
531f64fd | 406 | WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry)); |
a3222f88 | 407 | } else { |
a3222f88 FW |
408 | if (timer->it.cpu.firing) |
409 | ret = TIMER_RETRY; | |
410 | else | |
411 | list_del(&timer->it.cpu.entry); | |
3d7a1427 FW |
412 | |
413 | unlock_task_sighand(p, &flags); | |
1da177e4 | 414 | } |
a3222f88 FW |
415 | |
416 | if (!ret) | |
417 | put_task_struct(p); | |
1da177e4 | 418 | |
108150ea | 419 | return ret; |
1da177e4 LT |
420 | } |
421 | ||
af82eb3c | 422 | static void cleanup_timers_list(struct list_head *head) |
1a7fa510 FW |
423 | { |
424 | struct cpu_timer_list *timer, *next; | |
425 | ||
a0b2062b | 426 | list_for_each_entry_safe(timer, next, head, entry) |
1a7fa510 | 427 | list_del_init(&timer->entry); |
1a7fa510 FW |
428 | } |
429 | ||
1da177e4 LT |
430 | /* |
431 | * Clean out CPU timers still ticking when a thread exited. The task | |
432 | * pointer is cleared, and the expiry time is replaced with the residual | |
433 | * time for later timer_gettime calls to return. | |
434 | * This must be called with the siglock held. | |
435 | */ | |
af82eb3c | 436 | static void cleanup_timers(struct list_head *head) |
1da177e4 | 437 | { |
af82eb3c FW |
438 | cleanup_timers_list(head); |
439 | cleanup_timers_list(++head); | |
440 | cleanup_timers_list(++head); | |
1da177e4 LT |
441 | } |
442 | ||
443 | /* | |
444 | * These are both called with the siglock held, when the current thread | |
445 | * is being reaped. When the final (leader) thread in the group is reaped, | |
446 | * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit. | |
447 | */ | |
448 | void posix_cpu_timers_exit(struct task_struct *tsk) | |
449 | { | |
61337054 NK |
450 | add_device_randomness((const void*) &tsk->se.sum_exec_runtime, |
451 | sizeof(unsigned long long)); | |
af82eb3c | 452 | cleanup_timers(tsk->cpu_timers); |
1da177e4 LT |
453 | |
454 | } | |
455 | void posix_cpu_timers_exit_group(struct task_struct *tsk) | |
456 | { | |
af82eb3c | 457 | cleanup_timers(tsk->signal->cpu_timers); |
1da177e4 LT |
458 | } |
459 | ||
d1e3b6d1 SG |
460 | static inline int expires_gt(cputime_t expires, cputime_t new_exp) |
461 | { | |
64861634 | 462 | return expires == 0 || expires > new_exp; |
d1e3b6d1 SG |
463 | } |
464 | ||
1da177e4 LT |
465 | /* |
466 | * Insert the timer on the appropriate list before any timers that | |
e73d84e3 | 467 | * expire later. This must be called with the sighand lock held. |
1da177e4 | 468 | */ |
5eb9aa64 | 469 | static void arm_timer(struct k_itimer *timer) |
1da177e4 LT |
470 | { |
471 | struct task_struct *p = timer->it.cpu.task; | |
472 | struct list_head *head, *listpos; | |
5eb9aa64 | 473 | struct task_cputime *cputime_expires; |
1da177e4 LT |
474 | struct cpu_timer_list *const nt = &timer->it.cpu; |
475 | struct cpu_timer_list *next; | |
1da177e4 | 476 | |
5eb9aa64 SG |
477 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
478 | head = p->cpu_timers; | |
479 | cputime_expires = &p->cputime_expires; | |
480 | } else { | |
481 | head = p->signal->cpu_timers; | |
482 | cputime_expires = &p->signal->cputime_expires; | |
483 | } | |
1da177e4 LT |
484 | head += CPUCLOCK_WHICH(timer->it_clock); |
485 | ||
1da177e4 | 486 | listpos = head; |
5eb9aa64 | 487 | list_for_each_entry(next, head, entry) { |
55ccb616 | 488 | if (nt->expires < next->expires) |
5eb9aa64 SG |
489 | break; |
490 | listpos = &next->entry; | |
1da177e4 LT |
491 | } |
492 | list_add(&nt->entry, listpos); | |
493 | ||
494 | if (listpos == head) { | |
55ccb616 | 495 | unsigned long long exp = nt->expires; |
5eb9aa64 | 496 | |
1da177e4 | 497 | /* |
5eb9aa64 SG |
498 | * We are the new earliest-expiring POSIX 1.b timer, hence |
499 | * need to update expiration cache. Take into account that | |
500 | * for process timers we share expiration cache with itimers | |
501 | * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME. | |
1da177e4 LT |
502 | */ |
503 | ||
5eb9aa64 SG |
504 | switch (CPUCLOCK_WHICH(timer->it_clock)) { |
505 | case CPUCLOCK_PROF: | |
55ccb616 FW |
506 | if (expires_gt(cputime_expires->prof_exp, expires_to_cputime(exp))) |
507 | cputime_expires->prof_exp = expires_to_cputime(exp); | |
5eb9aa64 SG |
508 | break; |
509 | case CPUCLOCK_VIRT: | |
55ccb616 FW |
510 | if (expires_gt(cputime_expires->virt_exp, expires_to_cputime(exp))) |
511 | cputime_expires->virt_exp = expires_to_cputime(exp); | |
5eb9aa64 SG |
512 | break; |
513 | case CPUCLOCK_SCHED: | |
514 | if (cputime_expires->sched_exp == 0 || | |
55ccb616 FW |
515 | cputime_expires->sched_exp > exp) |
516 | cputime_expires->sched_exp = exp; | |
5eb9aa64 | 517 | break; |
1da177e4 | 518 | } |
b7878300 FW |
519 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) |
520 | tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER); | |
521 | else | |
522 | tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER); | |
1da177e4 | 523 | } |
1da177e4 LT |
524 | } |
525 | ||
526 | /* | |
527 | * The timer is locked, fire it and arrange for its reload. | |
528 | */ | |
529 | static void cpu_timer_fire(struct k_itimer *timer) | |
530 | { | |
1f169f84 SG |
531 | if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { |
532 | /* | |
533 | * User don't want any signal. | |
534 | */ | |
55ccb616 | 535 | timer->it.cpu.expires = 0; |
1f169f84 | 536 | } else if (unlikely(timer->sigq == NULL)) { |
1da177e4 LT |
537 | /* |
538 | * This a special case for clock_nanosleep, | |
539 | * not a normal timer from sys_timer_create. | |
540 | */ | |
541 | wake_up_process(timer->it_process); | |
55ccb616 FW |
542 | timer->it.cpu.expires = 0; |
543 | } else if (timer->it.cpu.incr == 0) { | |
1da177e4 LT |
544 | /* |
545 | * One-shot timer. Clear it as soon as it's fired. | |
546 | */ | |
547 | posix_timer_event(timer, 0); | |
55ccb616 | 548 | timer->it.cpu.expires = 0; |
1da177e4 LT |
549 | } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) { |
550 | /* | |
551 | * The signal did not get queued because the signal | |
552 | * was ignored, so we won't get any callback to | |
553 | * reload the timer. But we need to keep it | |
554 | * ticking in case the signal is deliverable next time. | |
555 | */ | |
556 | posix_cpu_timer_schedule(timer); | |
557 | } | |
558 | } | |
559 | ||
3997ad31 PZ |
560 | /* |
561 | * Sample a process (thread group) timer for the given group_leader task. | |
e73d84e3 FW |
562 | * Must be called with task sighand lock held for safe while_each_thread() |
563 | * traversal. | |
3997ad31 PZ |
564 | */ |
565 | static int cpu_timer_sample_group(const clockid_t which_clock, | |
566 | struct task_struct *p, | |
55ccb616 | 567 | unsigned long long *sample) |
3997ad31 PZ |
568 | { |
569 | struct task_cputime cputime; | |
570 | ||
571 | thread_group_cputimer(p, &cputime); | |
572 | switch (CPUCLOCK_WHICH(which_clock)) { | |
573 | default: | |
574 | return -EINVAL; | |
575 | case CPUCLOCK_PROF: | |
55ccb616 | 576 | *sample = cputime_to_expires(cputime.utime + cputime.stime); |
3997ad31 PZ |
577 | break; |
578 | case CPUCLOCK_VIRT: | |
55ccb616 | 579 | *sample = cputime_to_expires(cputime.utime); |
3997ad31 PZ |
580 | break; |
581 | case CPUCLOCK_SCHED: | |
23cfa361 | 582 | *sample = cputime.sum_exec_runtime; |
3997ad31 PZ |
583 | break; |
584 | } | |
585 | return 0; | |
586 | } | |
587 | ||
1da177e4 LT |
588 | /* |
589 | * Guts of sys_timer_settime for CPU timers. | |
590 | * This is called with the timer locked and interrupts disabled. | |
591 | * If we return TIMER_RETRY, it's necessary to release the timer's lock | |
592 | * and try again. (This happens when the timer is in the middle of firing.) | |
593 | */ | |
e73d84e3 | 594 | static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, |
bc2c8ea4 | 595 | struct itimerspec *new, struct itimerspec *old) |
1da177e4 | 596 | { |
e73d84e3 FW |
597 | unsigned long flags; |
598 | struct sighand_struct *sighand; | |
1da177e4 | 599 | struct task_struct *p = timer->it.cpu.task; |
55ccb616 | 600 | unsigned long long old_expires, new_expires, old_incr, val; |
1da177e4 LT |
601 | int ret; |
602 | ||
a3222f88 | 603 | WARN_ON_ONCE(p == NULL); |
1da177e4 LT |
604 | |
605 | new_expires = timespec_to_sample(timer->it_clock, &new->it_value); | |
606 | ||
1da177e4 | 607 | /* |
e73d84e3 FW |
608 | * Protect against sighand release/switch in exit/exec and p->cpu_timers |
609 | * and p->signal->cpu_timers read/write in arm_timer() | |
610 | */ | |
611 | sighand = lock_task_sighand(p, &flags); | |
612 | /* | |
613 | * If p has just been reaped, we can no | |
1da177e4 LT |
614 | * longer get any information about it at all. |
615 | */ | |
e73d84e3 | 616 | if (unlikely(sighand == NULL)) { |
1da177e4 LT |
617 | return -ESRCH; |
618 | } | |
619 | ||
620 | /* | |
621 | * Disarm any old timer after extracting its expiry time. | |
622 | */ | |
531f64fd | 623 | WARN_ON_ONCE(!irqs_disabled()); |
a69ac4a7 ON |
624 | |
625 | ret = 0; | |
ae1a78ee | 626 | old_incr = timer->it.cpu.incr; |
1da177e4 | 627 | old_expires = timer->it.cpu.expires; |
a69ac4a7 ON |
628 | if (unlikely(timer->it.cpu.firing)) { |
629 | timer->it.cpu.firing = -1; | |
630 | ret = TIMER_RETRY; | |
631 | } else | |
632 | list_del_init(&timer->it.cpu.entry); | |
1da177e4 LT |
633 | |
634 | /* | |
635 | * We need to sample the current value to convert the new | |
636 | * value from to relative and absolute, and to convert the | |
637 | * old value from absolute to relative. To set a process | |
638 | * timer, we need a sample to balance the thread expiry | |
639 | * times (in arm_timer). With an absolute time, we must | |
640 | * check if it's already passed. In short, we need a sample. | |
641 | */ | |
642 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
643 | cpu_clock_sample(timer->it_clock, p, &val); | |
644 | } else { | |
3997ad31 | 645 | cpu_timer_sample_group(timer->it_clock, p, &val); |
1da177e4 LT |
646 | } |
647 | ||
648 | if (old) { | |
55ccb616 | 649 | if (old_expires == 0) { |
1da177e4 LT |
650 | old->it_value.tv_sec = 0; |
651 | old->it_value.tv_nsec = 0; | |
652 | } else { | |
653 | /* | |
654 | * Update the timer in case it has | |
655 | * overrun already. If it has, | |
656 | * we'll report it as having overrun | |
657 | * and with the next reloaded timer | |
658 | * already ticking, though we are | |
659 | * swallowing that pending | |
660 | * notification here to install the | |
661 | * new setting. | |
662 | */ | |
663 | bump_cpu_timer(timer, val); | |
55ccb616 FW |
664 | if (val < timer->it.cpu.expires) { |
665 | old_expires = timer->it.cpu.expires - val; | |
1da177e4 LT |
666 | sample_to_timespec(timer->it_clock, |
667 | old_expires, | |
668 | &old->it_value); | |
669 | } else { | |
670 | old->it_value.tv_nsec = 1; | |
671 | old->it_value.tv_sec = 0; | |
672 | } | |
673 | } | |
674 | } | |
675 | ||
a69ac4a7 | 676 | if (unlikely(ret)) { |
1da177e4 LT |
677 | /* |
678 | * We are colliding with the timer actually firing. | |
679 | * Punt after filling in the timer's old value, and | |
680 | * disable this firing since we are already reporting | |
681 | * it as an overrun (thanks to bump_cpu_timer above). | |
682 | */ | |
e73d84e3 | 683 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
684 | goto out; |
685 | } | |
686 | ||
e73d84e3 | 687 | if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) { |
55ccb616 | 688 | new_expires += val; |
1da177e4 LT |
689 | } |
690 | ||
691 | /* | |
692 | * Install the new expiry time (or zero). | |
693 | * For a timer with no notification action, we don't actually | |
694 | * arm the timer (we'll just fake it for timer_gettime). | |
695 | */ | |
696 | timer->it.cpu.expires = new_expires; | |
55ccb616 | 697 | if (new_expires != 0 && val < new_expires) { |
5eb9aa64 | 698 | arm_timer(timer); |
1da177e4 LT |
699 | } |
700 | ||
e73d84e3 | 701 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
702 | /* |
703 | * Install the new reload setting, and | |
704 | * set up the signal and overrun bookkeeping. | |
705 | */ | |
706 | timer->it.cpu.incr = timespec_to_sample(timer->it_clock, | |
707 | &new->it_interval); | |
708 | ||
709 | /* | |
710 | * This acts as a modification timestamp for the timer, | |
711 | * so any automatic reload attempt will punt on seeing | |
712 | * that we have reset the timer manually. | |
713 | */ | |
714 | timer->it_requeue_pending = (timer->it_requeue_pending + 2) & | |
715 | ~REQUEUE_PENDING; | |
716 | timer->it_overrun_last = 0; | |
717 | timer->it_overrun = -1; | |
718 | ||
55ccb616 | 719 | if (new_expires != 0 && !(val < new_expires)) { |
1da177e4 LT |
720 | /* |
721 | * The designated time already passed, so we notify | |
722 | * immediately, even if the thread never runs to | |
723 | * accumulate more time on this clock. | |
724 | */ | |
725 | cpu_timer_fire(timer); | |
726 | } | |
727 | ||
728 | ret = 0; | |
729 | out: | |
730 | if (old) { | |
731 | sample_to_timespec(timer->it_clock, | |
ae1a78ee | 732 | old_incr, &old->it_interval); |
1da177e4 | 733 | } |
b7878300 | 734 | |
1da177e4 LT |
735 | return ret; |
736 | } | |
737 | ||
bc2c8ea4 | 738 | static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) |
1da177e4 | 739 | { |
55ccb616 | 740 | unsigned long long now; |
1da177e4 | 741 | struct task_struct *p = timer->it.cpu.task; |
1da177e4 | 742 | |
a3222f88 FW |
743 | WARN_ON_ONCE(p == NULL); |
744 | ||
1da177e4 LT |
745 | /* |
746 | * Easy part: convert the reload time. | |
747 | */ | |
748 | sample_to_timespec(timer->it_clock, | |
749 | timer->it.cpu.incr, &itp->it_interval); | |
750 | ||
55ccb616 | 751 | if (timer->it.cpu.expires == 0) { /* Timer not armed at all. */ |
1da177e4 LT |
752 | itp->it_value.tv_sec = itp->it_value.tv_nsec = 0; |
753 | return; | |
754 | } | |
755 | ||
1da177e4 LT |
756 | /* |
757 | * Sample the clock to take the difference with the expiry time. | |
758 | */ | |
759 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
760 | cpu_clock_sample(timer->it_clock, p, &now); | |
1da177e4 | 761 | } else { |
e73d84e3 FW |
762 | struct sighand_struct *sighand; |
763 | unsigned long flags; | |
764 | ||
765 | /* | |
766 | * Protect against sighand release/switch in exit/exec and | |
767 | * also make timer sampling safe if it ends up calling | |
768 | * thread_group_cputime(). | |
769 | */ | |
770 | sighand = lock_task_sighand(p, &flags); | |
771 | if (unlikely(sighand == NULL)) { | |
1da177e4 LT |
772 | /* |
773 | * The process has been reaped. | |
774 | * We can't even collect a sample any more. | |
775 | * Call the timer disarmed, nothing else to do. | |
776 | */ | |
55ccb616 | 777 | timer->it.cpu.expires = 0; |
a3222f88 FW |
778 | sample_to_timespec(timer->it_clock, timer->it.cpu.expires, |
779 | &itp->it_value); | |
1da177e4 | 780 | } else { |
3997ad31 | 781 | cpu_timer_sample_group(timer->it_clock, p, &now); |
e73d84e3 | 782 | unlock_task_sighand(p, &flags); |
1da177e4 | 783 | } |
1da177e4 LT |
784 | } |
785 | ||
55ccb616 | 786 | if (now < timer->it.cpu.expires) { |
1da177e4 | 787 | sample_to_timespec(timer->it_clock, |
55ccb616 | 788 | timer->it.cpu.expires - now, |
1da177e4 LT |
789 | &itp->it_value); |
790 | } else { | |
791 | /* | |
792 | * The timer should have expired already, but the firing | |
793 | * hasn't taken place yet. Say it's just about to expire. | |
794 | */ | |
795 | itp->it_value.tv_nsec = 1; | |
796 | itp->it_value.tv_sec = 0; | |
797 | } | |
798 | } | |
799 | ||
2473f3e7 FW |
800 | static unsigned long long |
801 | check_timers_list(struct list_head *timers, | |
802 | struct list_head *firing, | |
803 | unsigned long long curr) | |
804 | { | |
805 | int maxfire = 20; | |
806 | ||
807 | while (!list_empty(timers)) { | |
808 | struct cpu_timer_list *t; | |
809 | ||
810 | t = list_first_entry(timers, struct cpu_timer_list, entry); | |
811 | ||
812 | if (!--maxfire || curr < t->expires) | |
813 | return t->expires; | |
814 | ||
815 | t->firing = 1; | |
816 | list_move_tail(&t->entry, firing); | |
817 | } | |
818 | ||
819 | return 0; | |
820 | } | |
821 | ||
1da177e4 LT |
822 | /* |
823 | * Check for any per-thread CPU timers that have fired and move them off | |
824 | * the tsk->cpu_timers[N] list onto the firing list. Here we update the | |
825 | * tsk->it_*_expires values to reflect the remaining thread CPU timers. | |
826 | */ | |
827 | static void check_thread_timers(struct task_struct *tsk, | |
828 | struct list_head *firing) | |
829 | { | |
830 | struct list_head *timers = tsk->cpu_timers; | |
78f2c7db | 831 | struct signal_struct *const sig = tsk->signal; |
2473f3e7 FW |
832 | struct task_cputime *tsk_expires = &tsk->cputime_expires; |
833 | unsigned long long expires; | |
d4bb5274 | 834 | unsigned long soft; |
1da177e4 | 835 | |
934715a1 JL |
836 | /* |
837 | * If cputime_expires is zero, then there are no active | |
838 | * per thread CPU timers. | |
839 | */ | |
840 | if (task_cputime_zero(&tsk->cputime_expires)) | |
841 | return; | |
842 | ||
2473f3e7 FW |
843 | expires = check_timers_list(timers, firing, prof_ticks(tsk)); |
844 | tsk_expires->prof_exp = expires_to_cputime(expires); | |
1da177e4 | 845 | |
2473f3e7 FW |
846 | expires = check_timers_list(++timers, firing, virt_ticks(tsk)); |
847 | tsk_expires->virt_exp = expires_to_cputime(expires); | |
1da177e4 | 848 | |
2473f3e7 FW |
849 | tsk_expires->sched_exp = check_timers_list(++timers, firing, |
850 | tsk->se.sum_exec_runtime); | |
78f2c7db PZ |
851 | |
852 | /* | |
853 | * Check for the special case thread timers. | |
854 | */ | |
316c1608 | 855 | soft = READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur); |
d4bb5274 | 856 | if (soft != RLIM_INFINITY) { |
78d7d407 | 857 | unsigned long hard = |
316c1608 | 858 | READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max); |
78f2c7db | 859 | |
5a52dd50 PZ |
860 | if (hard != RLIM_INFINITY && |
861 | tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) { | |
78f2c7db PZ |
862 | /* |
863 | * At the hard limit, we just die. | |
864 | * No need to calculate anything else now. | |
865 | */ | |
866 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); | |
867 | return; | |
868 | } | |
d4bb5274 | 869 | if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) { |
78f2c7db PZ |
870 | /* |
871 | * At the soft limit, send a SIGXCPU every second. | |
872 | */ | |
d4bb5274 JS |
873 | if (soft < hard) { |
874 | soft += USEC_PER_SEC; | |
875 | sig->rlim[RLIMIT_RTTIME].rlim_cur = soft; | |
78f2c7db | 876 | } |
81d50bb2 HS |
877 | printk(KERN_INFO |
878 | "RT Watchdog Timeout: %s[%d]\n", | |
879 | tsk->comm, task_pid_nr(tsk)); | |
78f2c7db PZ |
880 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); |
881 | } | |
882 | } | |
b7878300 FW |
883 | if (task_cputime_zero(tsk_expires)) |
884 | tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER); | |
1da177e4 LT |
885 | } |
886 | ||
1018016c | 887 | static inline void stop_process_timers(struct signal_struct *sig) |
3fccfd67 | 888 | { |
15365c10 | 889 | struct thread_group_cputimer *cputimer = &sig->cputimer; |
3fccfd67 | 890 | |
1018016c | 891 | /* Turn off cputimer->running. This is done without locking. */ |
d5c373eb | 892 | WRITE_ONCE(cputimer->running, false); |
b7878300 | 893 | tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER); |
3fccfd67 PZ |
894 | } |
895 | ||
8356b5f9 SG |
896 | static u32 onecputick; |
897 | ||
42c4ab41 | 898 | static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, |
55ccb616 FW |
899 | unsigned long long *expires, |
900 | unsigned long long cur_time, int signo) | |
42c4ab41 | 901 | { |
64861634 | 902 | if (!it->expires) |
42c4ab41 SG |
903 | return; |
904 | ||
64861634 MS |
905 | if (cur_time >= it->expires) { |
906 | if (it->incr) { | |
907 | it->expires += it->incr; | |
8356b5f9 SG |
908 | it->error += it->incr_error; |
909 | if (it->error >= onecputick) { | |
64861634 | 910 | it->expires -= cputime_one_jiffy; |
8356b5f9 SG |
911 | it->error -= onecputick; |
912 | } | |
3f0a525e | 913 | } else { |
64861634 | 914 | it->expires = 0; |
3f0a525e | 915 | } |
42c4ab41 | 916 | |
3f0a525e XG |
917 | trace_itimer_expire(signo == SIGPROF ? |
918 | ITIMER_PROF : ITIMER_VIRTUAL, | |
919 | tsk->signal->leader_pid, cur_time); | |
42c4ab41 SG |
920 | __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); |
921 | } | |
922 | ||
64861634 | 923 | if (it->expires && (!*expires || it->expires < *expires)) { |
42c4ab41 SG |
924 | *expires = it->expires; |
925 | } | |
926 | } | |
927 | ||
1da177e4 LT |
928 | /* |
929 | * Check for any per-thread CPU timers that have fired and move them | |
930 | * off the tsk->*_timers list onto the firing list. Per-thread timers | |
931 | * have already been taken off. | |
932 | */ | |
933 | static void check_process_timers(struct task_struct *tsk, | |
934 | struct list_head *firing) | |
935 | { | |
936 | struct signal_struct *const sig = tsk->signal; | |
55ccb616 | 937 | unsigned long long utime, ptime, virt_expires, prof_expires; |
41b86e9c | 938 | unsigned long long sum_sched_runtime, sched_expires; |
1da177e4 | 939 | struct list_head *timers = sig->cpu_timers; |
f06febc9 | 940 | struct task_cputime cputime; |
d4bb5274 | 941 | unsigned long soft; |
1da177e4 | 942 | |
934715a1 JL |
943 | /* |
944 | * If cputimer is not running, then there are no active | |
945 | * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU). | |
946 | */ | |
947 | if (!READ_ONCE(tsk->signal->cputimer.running)) | |
948 | return; | |
949 | ||
c8d75aa4 JL |
950 | /* |
951 | * Signify that a thread is checking for process timers. | |
952 | * Write access to this field is protected by the sighand lock. | |
953 | */ | |
954 | sig->cputimer.checking_timer = true; | |
955 | ||
1da177e4 LT |
956 | /* |
957 | * Collect the current process totals. | |
958 | */ | |
4cd4c1b4 | 959 | thread_group_cputimer(tsk, &cputime); |
55ccb616 FW |
960 | utime = cputime_to_expires(cputime.utime); |
961 | ptime = utime + cputime_to_expires(cputime.stime); | |
f06febc9 | 962 | sum_sched_runtime = cputime.sum_exec_runtime; |
1da177e4 | 963 | |
2473f3e7 FW |
964 | prof_expires = check_timers_list(timers, firing, ptime); |
965 | virt_expires = check_timers_list(++timers, firing, utime); | |
966 | sched_expires = check_timers_list(++timers, firing, sum_sched_runtime); | |
1da177e4 LT |
967 | |
968 | /* | |
969 | * Check for the special case process timers. | |
970 | */ | |
42c4ab41 SG |
971 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime, |
972 | SIGPROF); | |
973 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime, | |
974 | SIGVTALRM); | |
316c1608 | 975 | soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur); |
d4bb5274 | 976 | if (soft != RLIM_INFINITY) { |
1da177e4 | 977 | unsigned long psecs = cputime_to_secs(ptime); |
78d7d407 | 978 | unsigned long hard = |
316c1608 | 979 | READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_max); |
1da177e4 | 980 | cputime_t x; |
d4bb5274 | 981 | if (psecs >= hard) { |
1da177e4 LT |
982 | /* |
983 | * At the hard limit, we just die. | |
984 | * No need to calculate anything else now. | |
985 | */ | |
986 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); | |
987 | return; | |
988 | } | |
d4bb5274 | 989 | if (psecs >= soft) { |
1da177e4 LT |
990 | /* |
991 | * At the soft limit, send a SIGXCPU every second. | |
992 | */ | |
993 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); | |
d4bb5274 JS |
994 | if (soft < hard) { |
995 | soft++; | |
996 | sig->rlim[RLIMIT_CPU].rlim_cur = soft; | |
1da177e4 LT |
997 | } |
998 | } | |
d4bb5274 | 999 | x = secs_to_cputime(soft); |
64861634 | 1000 | if (!prof_expires || x < prof_expires) { |
1da177e4 LT |
1001 | prof_expires = x; |
1002 | } | |
1003 | } | |
1004 | ||
55ccb616 FW |
1005 | sig->cputime_expires.prof_exp = expires_to_cputime(prof_expires); |
1006 | sig->cputime_expires.virt_exp = expires_to_cputime(virt_expires); | |
29f87b79 SG |
1007 | sig->cputime_expires.sched_exp = sched_expires; |
1008 | if (task_cputime_zero(&sig->cputime_expires)) | |
1009 | stop_process_timers(sig); | |
c8d75aa4 JL |
1010 | |
1011 | sig->cputimer.checking_timer = false; | |
1da177e4 LT |
1012 | } |
1013 | ||
1014 | /* | |
1015 | * This is called from the signal code (via do_schedule_next_timer) | |
1016 | * when the last timer signal was delivered and we have to reload the timer. | |
1017 | */ | |
1018 | void posix_cpu_timer_schedule(struct k_itimer *timer) | |
1019 | { | |
e73d84e3 FW |
1020 | struct sighand_struct *sighand; |
1021 | unsigned long flags; | |
1da177e4 | 1022 | struct task_struct *p = timer->it.cpu.task; |
55ccb616 | 1023 | unsigned long long now; |
1da177e4 | 1024 | |
a3222f88 | 1025 | WARN_ON_ONCE(p == NULL); |
1da177e4 LT |
1026 | |
1027 | /* | |
1028 | * Fetch the current sample and update the timer's expiry time. | |
1029 | */ | |
1030 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
1031 | cpu_clock_sample(timer->it_clock, p, &now); | |
1032 | bump_cpu_timer(timer, now); | |
724a3713 | 1033 | if (unlikely(p->exit_state)) |
708f430d | 1034 | goto out; |
724a3713 | 1035 | |
e73d84e3 FW |
1036 | /* Protect timer list r/w in arm_timer() */ |
1037 | sighand = lock_task_sighand(p, &flags); | |
1038 | if (!sighand) | |
1039 | goto out; | |
1da177e4 | 1040 | } else { |
e73d84e3 FW |
1041 | /* |
1042 | * Protect arm_timer() and timer sampling in case of call to | |
1043 | * thread_group_cputime(). | |
1044 | */ | |
1045 | sighand = lock_task_sighand(p, &flags); | |
1046 | if (unlikely(sighand == NULL)) { | |
1da177e4 LT |
1047 | /* |
1048 | * The process has been reaped. | |
1049 | * We can't even collect a sample any more. | |
1050 | */ | |
55ccb616 | 1051 | timer->it.cpu.expires = 0; |
c925077c | 1052 | goto out; |
1da177e4 | 1053 | } else if (unlikely(p->exit_state) && thread_group_empty(p)) { |
e73d84e3 | 1054 | unlock_task_sighand(p, &flags); |
d430b917 | 1055 | /* Optimizations: if the process is dying, no need to rearm */ |
c925077c | 1056 | goto out; |
1da177e4 | 1057 | } |
3997ad31 | 1058 | cpu_timer_sample_group(timer->it_clock, p, &now); |
1da177e4 | 1059 | bump_cpu_timer(timer, now); |
e73d84e3 | 1060 | /* Leave the sighand locked for the call below. */ |
1da177e4 LT |
1061 | } |
1062 | ||
1063 | /* | |
1064 | * Now re-arm for the new expiry time. | |
1065 | */ | |
531f64fd | 1066 | WARN_ON_ONCE(!irqs_disabled()); |
5eb9aa64 | 1067 | arm_timer(timer); |
e73d84e3 | 1068 | unlock_task_sighand(p, &flags); |
708f430d RM |
1069 | |
1070 | out: | |
1071 | timer->it_overrun_last = timer->it_overrun; | |
1072 | timer->it_overrun = -1; | |
1073 | ++timer->it_requeue_pending; | |
1da177e4 LT |
1074 | } |
1075 | ||
f06febc9 FM |
1076 | /** |
1077 | * task_cputime_expired - Compare two task_cputime entities. | |
1078 | * | |
1079 | * @sample: The task_cputime structure to be checked for expiration. | |
1080 | * @expires: Expiration times, against which @sample will be checked. | |
1081 | * | |
1082 | * Checks @sample against @expires to see if any field of @sample has expired. | |
1083 | * Returns true if any field of the former is greater than the corresponding | |
1084 | * field of the latter if the latter field is set. Otherwise returns false. | |
1085 | */ | |
1086 | static inline int task_cputime_expired(const struct task_cputime *sample, | |
1087 | const struct task_cputime *expires) | |
1088 | { | |
64861634 | 1089 | if (expires->utime && sample->utime >= expires->utime) |
f06febc9 | 1090 | return 1; |
64861634 | 1091 | if (expires->stime && sample->utime + sample->stime >= expires->stime) |
f06febc9 FM |
1092 | return 1; |
1093 | if (expires->sum_exec_runtime != 0 && | |
1094 | sample->sum_exec_runtime >= expires->sum_exec_runtime) | |
1095 | return 1; | |
1096 | return 0; | |
1097 | } | |
1098 | ||
1099 | /** | |
1100 | * fastpath_timer_check - POSIX CPU timers fast path. | |
1101 | * | |
1102 | * @tsk: The task (thread) being checked. | |
f06febc9 | 1103 | * |
bb34d92f FM |
1104 | * Check the task and thread group timers. If both are zero (there are no |
1105 | * timers set) return false. Otherwise snapshot the task and thread group | |
1106 | * timers and compare them with the corresponding expiration times. Return | |
1107 | * true if a timer has expired, else return false. | |
f06febc9 | 1108 | */ |
bb34d92f | 1109 | static inline int fastpath_timer_check(struct task_struct *tsk) |
f06febc9 | 1110 | { |
ad133ba3 | 1111 | struct signal_struct *sig; |
bb34d92f | 1112 | |
bb34d92f | 1113 | if (!task_cputime_zero(&tsk->cputime_expires)) { |
7c177d99 | 1114 | struct task_cputime task_sample; |
bb34d92f | 1115 | |
7c177d99 JL |
1116 | task_cputime(tsk, &task_sample.utime, &task_sample.stime); |
1117 | task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime; | |
bb34d92f FM |
1118 | if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) |
1119 | return 1; | |
1120 | } | |
ad133ba3 ON |
1121 | |
1122 | sig = tsk->signal; | |
c8d75aa4 JL |
1123 | /* |
1124 | * Check if thread group timers expired when the cputimer is | |
1125 | * running and no other thread in the group is already checking | |
1126 | * for thread group cputimers. These fields are read without the | |
1127 | * sighand lock. However, this is fine because this is meant to | |
1128 | * be a fastpath heuristic to determine whether we should try to | |
1129 | * acquire the sighand lock to check/handle timers. | |
1130 | * | |
1131 | * In the worst case scenario, if 'running' or 'checking_timer' gets | |
1132 | * set but the current thread doesn't see the change yet, we'll wait | |
1133 | * until the next thread in the group gets a scheduler interrupt to | |
1134 | * handle the timer. This isn't an issue in practice because these | |
1135 | * types of delays with signals actually getting sent are expected. | |
1136 | */ | |
1137 | if (READ_ONCE(sig->cputimer.running) && | |
1138 | !READ_ONCE(sig->cputimer.checking_timer)) { | |
bb34d92f FM |
1139 | struct task_cputime group_sample; |
1140 | ||
71107445 | 1141 | sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic); |
8d1f431c | 1142 | |
bb34d92f FM |
1143 | if (task_cputime_expired(&group_sample, &sig->cputime_expires)) |
1144 | return 1; | |
1145 | } | |
37bebc70 | 1146 | |
f55db609 | 1147 | return 0; |
f06febc9 FM |
1148 | } |
1149 | ||
1da177e4 LT |
1150 | /* |
1151 | * This is called from the timer interrupt handler. The irq handler has | |
1152 | * already updated our counts. We need to check if any timers fire now. | |
1153 | * Interrupts are disabled. | |
1154 | */ | |
1155 | void run_posix_cpu_timers(struct task_struct *tsk) | |
1156 | { | |
1157 | LIST_HEAD(firing); | |
1158 | struct k_itimer *timer, *next; | |
0bdd2ed4 | 1159 | unsigned long flags; |
1da177e4 | 1160 | |
531f64fd | 1161 | WARN_ON_ONCE(!irqs_disabled()); |
1da177e4 | 1162 | |
1da177e4 | 1163 | /* |
f06febc9 | 1164 | * The fast path checks that there are no expired thread or thread |
bb34d92f | 1165 | * group timers. If that's so, just return. |
1da177e4 | 1166 | */ |
bb34d92f | 1167 | if (!fastpath_timer_check(tsk)) |
f06febc9 | 1168 | return; |
5ce73a4a | 1169 | |
0bdd2ed4 ON |
1170 | if (!lock_task_sighand(tsk, &flags)) |
1171 | return; | |
bb34d92f FM |
1172 | /* |
1173 | * Here we take off tsk->signal->cpu_timers[N] and | |
1174 | * tsk->cpu_timers[N] all the timers that are firing, and | |
1175 | * put them on the firing list. | |
1176 | */ | |
1177 | check_thread_timers(tsk, &firing); | |
934715a1 JL |
1178 | |
1179 | check_process_timers(tsk, &firing); | |
1da177e4 | 1180 | |
bb34d92f FM |
1181 | /* |
1182 | * We must release these locks before taking any timer's lock. | |
1183 | * There is a potential race with timer deletion here, as the | |
1184 | * siglock now protects our private firing list. We have set | |
1185 | * the firing flag in each timer, so that a deletion attempt | |
1186 | * that gets the timer lock before we do will give it up and | |
1187 | * spin until we've taken care of that timer below. | |
1188 | */ | |
0bdd2ed4 | 1189 | unlock_task_sighand(tsk, &flags); |
1da177e4 LT |
1190 | |
1191 | /* | |
1192 | * Now that all the timers on our list have the firing flag, | |
25985edc | 1193 | * no one will touch their list entries but us. We'll take |
1da177e4 LT |
1194 | * each timer's lock before clearing its firing flag, so no |
1195 | * timer call will interfere. | |
1196 | */ | |
1197 | list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) { | |
6e85c5ba HS |
1198 | int cpu_firing; |
1199 | ||
1da177e4 LT |
1200 | spin_lock(&timer->it_lock); |
1201 | list_del_init(&timer->it.cpu.entry); | |
6e85c5ba | 1202 | cpu_firing = timer->it.cpu.firing; |
1da177e4 LT |
1203 | timer->it.cpu.firing = 0; |
1204 | /* | |
1205 | * The firing flag is -1 if we collided with a reset | |
1206 | * of the timer, which already reported this | |
1207 | * almost-firing as an overrun. So don't generate an event. | |
1208 | */ | |
6e85c5ba | 1209 | if (likely(cpu_firing >= 0)) |
1da177e4 | 1210 | cpu_timer_fire(timer); |
1da177e4 LT |
1211 | spin_unlock(&timer->it_lock); |
1212 | } | |
1213 | } | |
1214 | ||
1215 | /* | |
f55db609 | 1216 | * Set one of the process-wide special case CPU timers or RLIMIT_CPU. |
f06febc9 | 1217 | * The tsk->sighand->siglock must be held by the caller. |
1da177e4 LT |
1218 | */ |
1219 | void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, | |
1220 | cputime_t *newval, cputime_t *oldval) | |
1221 | { | |
55ccb616 | 1222 | unsigned long long now; |
1da177e4 | 1223 | |
531f64fd | 1224 | WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED); |
4cd4c1b4 | 1225 | cpu_timer_sample_group(clock_idx, tsk, &now); |
1da177e4 LT |
1226 | |
1227 | if (oldval) { | |
f55db609 SG |
1228 | /* |
1229 | * We are setting itimer. The *oldval is absolute and we update | |
1230 | * it to be relative, *newval argument is relative and we update | |
1231 | * it to be absolute. | |
1232 | */ | |
64861634 | 1233 | if (*oldval) { |
55ccb616 | 1234 | if (*oldval <= now) { |
1da177e4 | 1235 | /* Just about to fire. */ |
a42548a1 | 1236 | *oldval = cputime_one_jiffy; |
1da177e4 | 1237 | } else { |
55ccb616 | 1238 | *oldval -= now; |
1da177e4 LT |
1239 | } |
1240 | } | |
1241 | ||
64861634 | 1242 | if (!*newval) |
b7878300 | 1243 | return; |
55ccb616 | 1244 | *newval += now; |
1da177e4 LT |
1245 | } |
1246 | ||
1247 | /* | |
f55db609 SG |
1248 | * Update expiration cache if we are the earliest timer, or eventually |
1249 | * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire. | |
1da177e4 | 1250 | */ |
f55db609 SG |
1251 | switch (clock_idx) { |
1252 | case CPUCLOCK_PROF: | |
1253 | if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval)) | |
f06febc9 | 1254 | tsk->signal->cputime_expires.prof_exp = *newval; |
f55db609 SG |
1255 | break; |
1256 | case CPUCLOCK_VIRT: | |
1257 | if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval)) | |
f06febc9 | 1258 | tsk->signal->cputime_expires.virt_exp = *newval; |
f55db609 | 1259 | break; |
1da177e4 | 1260 | } |
b7878300 FW |
1261 | |
1262 | tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER); | |
1da177e4 LT |
1263 | } |
1264 | ||
e4b76555 TA |
1265 | static int do_cpu_nanosleep(const clockid_t which_clock, int flags, |
1266 | struct timespec *rqtp, struct itimerspec *it) | |
1da177e4 | 1267 | { |
1da177e4 LT |
1268 | struct k_itimer timer; |
1269 | int error; | |
1270 | ||
1da177e4 LT |
1271 | /* |
1272 | * Set up a temporary timer and then wait for it to go off. | |
1273 | */ | |
1274 | memset(&timer, 0, sizeof timer); | |
1275 | spin_lock_init(&timer.it_lock); | |
1276 | timer.it_clock = which_clock; | |
1277 | timer.it_overrun = -1; | |
1278 | error = posix_cpu_timer_create(&timer); | |
1279 | timer.it_process = current; | |
1280 | if (!error) { | |
1da177e4 | 1281 | static struct itimerspec zero_it; |
e4b76555 TA |
1282 | |
1283 | memset(it, 0, sizeof *it); | |
1284 | it->it_value = *rqtp; | |
1da177e4 LT |
1285 | |
1286 | spin_lock_irq(&timer.it_lock); | |
e4b76555 | 1287 | error = posix_cpu_timer_set(&timer, flags, it, NULL); |
1da177e4 LT |
1288 | if (error) { |
1289 | spin_unlock_irq(&timer.it_lock); | |
1290 | return error; | |
1291 | } | |
1292 | ||
1293 | while (!signal_pending(current)) { | |
55ccb616 | 1294 | if (timer.it.cpu.expires == 0) { |
1da177e4 | 1295 | /* |
e6c42c29 SG |
1296 | * Our timer fired and was reset, below |
1297 | * deletion can not fail. | |
1da177e4 | 1298 | */ |
e6c42c29 | 1299 | posix_cpu_timer_del(&timer); |
1da177e4 LT |
1300 | spin_unlock_irq(&timer.it_lock); |
1301 | return 0; | |
1302 | } | |
1303 | ||
1304 | /* | |
1305 | * Block until cpu_timer_fire (or a signal) wakes us. | |
1306 | */ | |
1307 | __set_current_state(TASK_INTERRUPTIBLE); | |
1308 | spin_unlock_irq(&timer.it_lock); | |
1309 | schedule(); | |
1310 | spin_lock_irq(&timer.it_lock); | |
1311 | } | |
1312 | ||
1313 | /* | |
1314 | * We were interrupted by a signal. | |
1315 | */ | |
1316 | sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); | |
e6c42c29 SG |
1317 | error = posix_cpu_timer_set(&timer, 0, &zero_it, it); |
1318 | if (!error) { | |
1319 | /* | |
1320 | * Timer is now unarmed, deletion can not fail. | |
1321 | */ | |
1322 | posix_cpu_timer_del(&timer); | |
1323 | } | |
1da177e4 LT |
1324 | spin_unlock_irq(&timer.it_lock); |
1325 | ||
e6c42c29 SG |
1326 | while (error == TIMER_RETRY) { |
1327 | /* | |
1328 | * We need to handle case when timer was or is in the | |
1329 | * middle of firing. In other cases we already freed | |
1330 | * resources. | |
1331 | */ | |
1332 | spin_lock_irq(&timer.it_lock); | |
1333 | error = posix_cpu_timer_del(&timer); | |
1334 | spin_unlock_irq(&timer.it_lock); | |
1335 | } | |
1336 | ||
e4b76555 | 1337 | if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { |
1da177e4 LT |
1338 | /* |
1339 | * It actually did fire already. | |
1340 | */ | |
1341 | return 0; | |
1342 | } | |
1343 | ||
e4b76555 TA |
1344 | error = -ERESTART_RESTARTBLOCK; |
1345 | } | |
1346 | ||
1347 | return error; | |
1348 | } | |
1349 | ||
bc2c8ea4 TG |
1350 | static long posix_cpu_nsleep_restart(struct restart_block *restart_block); |
1351 | ||
1352 | static int posix_cpu_nsleep(const clockid_t which_clock, int flags, | |
1353 | struct timespec *rqtp, struct timespec __user *rmtp) | |
e4b76555 | 1354 | { |
f56141e3 | 1355 | struct restart_block *restart_block = ¤t->restart_block; |
e4b76555 TA |
1356 | struct itimerspec it; |
1357 | int error; | |
1358 | ||
1359 | /* | |
1360 | * Diagnose required errors first. | |
1361 | */ | |
1362 | if (CPUCLOCK_PERTHREAD(which_clock) && | |
1363 | (CPUCLOCK_PID(which_clock) == 0 || | |
1364 | CPUCLOCK_PID(which_clock) == current->pid)) | |
1365 | return -EINVAL; | |
1366 | ||
1367 | error = do_cpu_nanosleep(which_clock, flags, rqtp, &it); | |
1368 | ||
1369 | if (error == -ERESTART_RESTARTBLOCK) { | |
1370 | ||
3751f9f2 | 1371 | if (flags & TIMER_ABSTIME) |
e4b76555 | 1372 | return -ERESTARTNOHAND; |
1da177e4 | 1373 | /* |
3751f9f2 TG |
1374 | * Report back to the user the time still remaining. |
1375 | */ | |
1376 | if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) | |
1da177e4 LT |
1377 | return -EFAULT; |
1378 | ||
1711ef38 | 1379 | restart_block->fn = posix_cpu_nsleep_restart; |
ab8177bc | 1380 | restart_block->nanosleep.clockid = which_clock; |
3751f9f2 TG |
1381 | restart_block->nanosleep.rmtp = rmtp; |
1382 | restart_block->nanosleep.expires = timespec_to_ns(rqtp); | |
1da177e4 | 1383 | } |
1da177e4 LT |
1384 | return error; |
1385 | } | |
1386 | ||
bc2c8ea4 | 1387 | static long posix_cpu_nsleep_restart(struct restart_block *restart_block) |
1da177e4 | 1388 | { |
ab8177bc | 1389 | clockid_t which_clock = restart_block->nanosleep.clockid; |
97735f25 | 1390 | struct timespec t; |
e4b76555 TA |
1391 | struct itimerspec it; |
1392 | int error; | |
97735f25 | 1393 | |
3751f9f2 | 1394 | t = ns_to_timespec(restart_block->nanosleep.expires); |
97735f25 | 1395 | |
e4b76555 TA |
1396 | error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it); |
1397 | ||
1398 | if (error == -ERESTART_RESTARTBLOCK) { | |
3751f9f2 | 1399 | struct timespec __user *rmtp = restart_block->nanosleep.rmtp; |
e4b76555 | 1400 | /* |
3751f9f2 TG |
1401 | * Report back to the user the time still remaining. |
1402 | */ | |
1403 | if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) | |
e4b76555 TA |
1404 | return -EFAULT; |
1405 | ||
3751f9f2 | 1406 | restart_block->nanosleep.expires = timespec_to_ns(&t); |
e4b76555 TA |
1407 | } |
1408 | return error; | |
1409 | ||
1da177e4 LT |
1410 | } |
1411 | ||
1da177e4 LT |
1412 | #define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED) |
1413 | #define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED) | |
1414 | ||
a924b04d TG |
1415 | static int process_cpu_clock_getres(const clockid_t which_clock, |
1416 | struct timespec *tp) | |
1da177e4 LT |
1417 | { |
1418 | return posix_cpu_clock_getres(PROCESS_CLOCK, tp); | |
1419 | } | |
a924b04d TG |
1420 | static int process_cpu_clock_get(const clockid_t which_clock, |
1421 | struct timespec *tp) | |
1da177e4 LT |
1422 | { |
1423 | return posix_cpu_clock_get(PROCESS_CLOCK, tp); | |
1424 | } | |
1425 | static int process_cpu_timer_create(struct k_itimer *timer) | |
1426 | { | |
1427 | timer->it_clock = PROCESS_CLOCK; | |
1428 | return posix_cpu_timer_create(timer); | |
1429 | } | |
a924b04d | 1430 | static int process_cpu_nsleep(const clockid_t which_clock, int flags, |
97735f25 TG |
1431 | struct timespec *rqtp, |
1432 | struct timespec __user *rmtp) | |
1da177e4 | 1433 | { |
97735f25 | 1434 | return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp); |
1da177e4 | 1435 | } |
1711ef38 TA |
1436 | static long process_cpu_nsleep_restart(struct restart_block *restart_block) |
1437 | { | |
1438 | return -EINVAL; | |
1439 | } | |
a924b04d TG |
1440 | static int thread_cpu_clock_getres(const clockid_t which_clock, |
1441 | struct timespec *tp) | |
1da177e4 LT |
1442 | { |
1443 | return posix_cpu_clock_getres(THREAD_CLOCK, tp); | |
1444 | } | |
a924b04d TG |
1445 | static int thread_cpu_clock_get(const clockid_t which_clock, |
1446 | struct timespec *tp) | |
1da177e4 LT |
1447 | { |
1448 | return posix_cpu_clock_get(THREAD_CLOCK, tp); | |
1449 | } | |
1450 | static int thread_cpu_timer_create(struct k_itimer *timer) | |
1451 | { | |
1452 | timer->it_clock = THREAD_CLOCK; | |
1453 | return posix_cpu_timer_create(timer); | |
1454 | } | |
1da177e4 | 1455 | |
1976945e TG |
1456 | struct k_clock clock_posix_cpu = { |
1457 | .clock_getres = posix_cpu_clock_getres, | |
1458 | .clock_set = posix_cpu_clock_set, | |
1459 | .clock_get = posix_cpu_clock_get, | |
1460 | .timer_create = posix_cpu_timer_create, | |
1461 | .nsleep = posix_cpu_nsleep, | |
1462 | .nsleep_restart = posix_cpu_nsleep_restart, | |
1463 | .timer_set = posix_cpu_timer_set, | |
1464 | .timer_del = posix_cpu_timer_del, | |
1465 | .timer_get = posix_cpu_timer_get, | |
1466 | }; | |
1467 | ||
1da177e4 LT |
1468 | static __init int init_posix_cpu_timers(void) |
1469 | { | |
1470 | struct k_clock process = { | |
2fd1f040 TG |
1471 | .clock_getres = process_cpu_clock_getres, |
1472 | .clock_get = process_cpu_clock_get, | |
2fd1f040 TG |
1473 | .timer_create = process_cpu_timer_create, |
1474 | .nsleep = process_cpu_nsleep, | |
1475 | .nsleep_restart = process_cpu_nsleep_restart, | |
1da177e4 LT |
1476 | }; |
1477 | struct k_clock thread = { | |
2fd1f040 TG |
1478 | .clock_getres = thread_cpu_clock_getres, |
1479 | .clock_get = thread_cpu_clock_get, | |
2fd1f040 | 1480 | .timer_create = thread_cpu_timer_create, |
1da177e4 | 1481 | }; |
8356b5f9 | 1482 | struct timespec ts; |
1da177e4 | 1483 | |
52708737 TG |
1484 | posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process); |
1485 | posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread); | |
1da177e4 | 1486 | |
a42548a1 | 1487 | cputime_to_timespec(cputime_one_jiffy, &ts); |
8356b5f9 SG |
1488 | onecputick = ts.tv_nsec; |
1489 | WARN_ON(ts.tv_sec != 0); | |
1490 | ||
1da177e4 LT |
1491 | return 0; |
1492 | } | |
1493 | __initcall(init_posix_cpu_timers); |