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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 | 8 | #include <linux/math64.h> |
7c0f6ba6 | 9 | #include <linux/uaccess.h> |
bb34d92f | 10 | #include <linux/kernel_stat.h> |
3f0a525e | 11 | #include <trace/events/timer.h> |
a8572160 FW |
12 | #include <linux/tick.h> |
13 | #include <linux/workqueue.h> | |
1da177e4 | 14 | |
f06febc9 | 15 | /* |
f55db609 SG |
16 | * Called after updating RLIMIT_CPU to run cpu timer and update |
17 | * tsk->signal->cputime_expires expiration cache if necessary. Needs | |
18 | * siglock protection since other code may update expiration cache as | |
19 | * well. | |
f06febc9 | 20 | */ |
5ab46b34 | 21 | void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new) |
f06febc9 | 22 | { |
42c4ab41 | 23 | cputime_t cputime = secs_to_cputime(rlim_new); |
f06febc9 | 24 | |
5ab46b34 JS |
25 | spin_lock_irq(&task->sighand->siglock); |
26 | set_process_cpu_timer(task, CPUCLOCK_PROF, &cputime, NULL); | |
27 | spin_unlock_irq(&task->sighand->siglock); | |
f06febc9 FM |
28 | } |
29 | ||
a924b04d | 30 | static int check_clock(const clockid_t which_clock) |
1da177e4 LT |
31 | { |
32 | int error = 0; | |
33 | struct task_struct *p; | |
34 | const pid_t pid = CPUCLOCK_PID(which_clock); | |
35 | ||
36 | if (CPUCLOCK_WHICH(which_clock) >= CPUCLOCK_MAX) | |
37 | return -EINVAL; | |
38 | ||
39 | if (pid == 0) | |
40 | return 0; | |
41 | ||
c0deae8c | 42 | rcu_read_lock(); |
8dc86af0 | 43 | p = find_task_by_vpid(pid); |
bac0abd6 | 44 | if (!p || !(CPUCLOCK_PERTHREAD(which_clock) ? |
c0deae8c | 45 | same_thread_group(p, current) : has_group_leader_pid(p))) { |
1da177e4 LT |
46 | error = -EINVAL; |
47 | } | |
c0deae8c | 48 | rcu_read_unlock(); |
1da177e4 LT |
49 | |
50 | return error; | |
51 | } | |
52 | ||
55ccb616 | 53 | static inline unsigned long long |
a924b04d | 54 | timespec_to_sample(const clockid_t which_clock, const struct timespec *tp) |
1da177e4 | 55 | { |
55ccb616 FW |
56 | unsigned long long ret; |
57 | ||
58 | ret = 0; /* high half always zero when .cpu used */ | |
1da177e4 | 59 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { |
55ccb616 | 60 | ret = (unsigned long long)tp->tv_sec * NSEC_PER_SEC + tp->tv_nsec; |
1da177e4 | 61 | } else { |
55ccb616 | 62 | ret = cputime_to_expires(timespec_to_cputime(tp)); |
1da177e4 LT |
63 | } |
64 | return ret; | |
65 | } | |
66 | ||
a924b04d | 67 | static void sample_to_timespec(const clockid_t which_clock, |
55ccb616 | 68 | unsigned long long expires, |
1da177e4 LT |
69 | struct timespec *tp) |
70 | { | |
f8bd2258 | 71 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) |
55ccb616 | 72 | *tp = ns_to_timespec(expires); |
f8bd2258 | 73 | else |
55ccb616 | 74 | cputime_to_timespec((__force cputime_t)expires, tp); |
1da177e4 LT |
75 | } |
76 | ||
77 | /* | |
78 | * Update expiry time from increment, and increase overrun count, | |
79 | * given the current clock sample. | |
80 | */ | |
7a4ed937 | 81 | static void bump_cpu_timer(struct k_itimer *timer, |
55ccb616 | 82 | unsigned long long now) |
1da177e4 LT |
83 | { |
84 | int i; | |
55ccb616 | 85 | unsigned long long delta, incr; |
1da177e4 | 86 | |
55ccb616 | 87 | if (timer->it.cpu.incr == 0) |
1da177e4 LT |
88 | return; |
89 | ||
55ccb616 FW |
90 | if (now < timer->it.cpu.expires) |
91 | return; | |
1da177e4 | 92 | |
55ccb616 FW |
93 | incr = timer->it.cpu.incr; |
94 | delta = now + incr - timer->it.cpu.expires; | |
1da177e4 | 95 | |
55ccb616 FW |
96 | /* Don't use (incr*2 < delta), incr*2 might overflow. */ |
97 | for (i = 0; incr < delta - incr; i++) | |
98 | incr = incr << 1; | |
99 | ||
100 | for (; i >= 0; incr >>= 1, i--) { | |
101 | if (delta < incr) | |
102 | continue; | |
103 | ||
104 | timer->it.cpu.expires += incr; | |
105 | timer->it_overrun += 1 << i; | |
106 | delta -= incr; | |
1da177e4 LT |
107 | } |
108 | } | |
109 | ||
555347f6 FW |
110 | /** |
111 | * task_cputime_zero - Check a task_cputime struct for all zero fields. | |
112 | * | |
113 | * @cputime: The struct to compare. | |
114 | * | |
115 | * Checks @cputime to see if all fields are zero. Returns true if all fields | |
116 | * are zero, false if any field is nonzero. | |
117 | */ | |
118 | static inline int task_cputime_zero(const struct task_cputime *cputime) | |
119 | { | |
120 | if (!cputime->utime && !cputime->stime && !cputime->sum_exec_runtime) | |
121 | return 1; | |
122 | return 0; | |
123 | } | |
124 | ||
55ccb616 | 125 | static inline unsigned long long prof_ticks(struct task_struct *p) |
1da177e4 | 126 | { |
6fac4829 FW |
127 | cputime_t utime, stime; |
128 | ||
129 | task_cputime(p, &utime, &stime); | |
130 | ||
55ccb616 | 131 | return cputime_to_expires(utime + stime); |
1da177e4 | 132 | } |
55ccb616 | 133 | static inline unsigned long long virt_ticks(struct task_struct *p) |
1da177e4 | 134 | { |
353c50eb | 135 | cputime_t utime, stime; |
6fac4829 | 136 | |
353c50eb | 137 | task_cputime(p, &utime, &stime); |
6fac4829 | 138 | |
55ccb616 | 139 | return cputime_to_expires(utime); |
1da177e4 | 140 | } |
1da177e4 | 141 | |
bc2c8ea4 TG |
142 | static int |
143 | posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp) | |
1da177e4 LT |
144 | { |
145 | int error = check_clock(which_clock); | |
146 | if (!error) { | |
147 | tp->tv_sec = 0; | |
148 | tp->tv_nsec = ((NSEC_PER_SEC + HZ - 1) / HZ); | |
149 | if (CPUCLOCK_WHICH(which_clock) == CPUCLOCK_SCHED) { | |
150 | /* | |
151 | * If sched_clock is using a cycle counter, we | |
152 | * don't have any idea of its true resolution | |
153 | * exported, but it is much more than 1s/HZ. | |
154 | */ | |
155 | tp->tv_nsec = 1; | |
156 | } | |
157 | } | |
158 | return error; | |
159 | } | |
160 | ||
bc2c8ea4 TG |
161 | static int |
162 | posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp) | |
1da177e4 LT |
163 | { |
164 | /* | |
165 | * You can never reset a CPU clock, but we check for other errors | |
166 | * in the call before failing with EPERM. | |
167 | */ | |
168 | int error = check_clock(which_clock); | |
169 | if (error == 0) { | |
170 | error = -EPERM; | |
171 | } | |
172 | return error; | |
173 | } | |
174 | ||
175 | ||
176 | /* | |
177 | * Sample a per-thread clock for the given task. | |
178 | */ | |
a924b04d | 179 | static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p, |
55ccb616 | 180 | unsigned long long *sample) |
1da177e4 LT |
181 | { |
182 | switch (CPUCLOCK_WHICH(which_clock)) { | |
183 | default: | |
184 | return -EINVAL; | |
185 | case CPUCLOCK_PROF: | |
55ccb616 | 186 | *sample = prof_ticks(p); |
1da177e4 LT |
187 | break; |
188 | case CPUCLOCK_VIRT: | |
55ccb616 | 189 | *sample = virt_ticks(p); |
1da177e4 LT |
190 | break; |
191 | case CPUCLOCK_SCHED: | |
55ccb616 | 192 | *sample = task_sched_runtime(p); |
1da177e4 LT |
193 | break; |
194 | } | |
195 | return 0; | |
196 | } | |
197 | ||
1018016c JL |
198 | /* |
199 | * Set cputime to sum_cputime if sum_cputime > cputime. Use cmpxchg | |
200 | * to avoid race conditions with concurrent updates to cputime. | |
201 | */ | |
202 | static inline void __update_gt_cputime(atomic64_t *cputime, u64 sum_cputime) | |
4da94d49 | 203 | { |
1018016c JL |
204 | u64 curr_cputime; |
205 | retry: | |
206 | curr_cputime = atomic64_read(cputime); | |
207 | if (sum_cputime > curr_cputime) { | |
208 | if (atomic64_cmpxchg(cputime, curr_cputime, sum_cputime) != curr_cputime) | |
209 | goto retry; | |
210 | } | |
211 | } | |
4da94d49 | 212 | |
71107445 | 213 | static void update_gt_cputime(struct task_cputime_atomic *cputime_atomic, struct task_cputime *sum) |
1018016c | 214 | { |
71107445 JL |
215 | __update_gt_cputime(&cputime_atomic->utime, sum->utime); |
216 | __update_gt_cputime(&cputime_atomic->stime, sum->stime); | |
217 | __update_gt_cputime(&cputime_atomic->sum_exec_runtime, sum->sum_exec_runtime); | |
1018016c | 218 | } |
4da94d49 | 219 | |
71107445 JL |
220 | /* Sample task_cputime_atomic values in "atomic_timers", store results in "times". */ |
221 | static inline void sample_cputime_atomic(struct task_cputime *times, | |
222 | struct task_cputime_atomic *atomic_times) | |
1018016c | 223 | { |
71107445 JL |
224 | times->utime = atomic64_read(&atomic_times->utime); |
225 | times->stime = atomic64_read(&atomic_times->stime); | |
226 | times->sum_exec_runtime = atomic64_read(&atomic_times->sum_exec_runtime); | |
4da94d49 PZ |
227 | } |
228 | ||
229 | void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times) | |
230 | { | |
231 | struct thread_group_cputimer *cputimer = &tsk->signal->cputimer; | |
232 | struct task_cputime sum; | |
4da94d49 | 233 | |
1018016c JL |
234 | /* Check if cputimer isn't running. This is accessed without locking. */ |
235 | if (!READ_ONCE(cputimer->running)) { | |
4da94d49 PZ |
236 | /* |
237 | * The POSIX timer interface allows for absolute time expiry | |
238 | * values through the TIMER_ABSTIME flag, therefore we have | |
1018016c | 239 | * to synchronize the timer to the clock every time we start it. |
4da94d49 PZ |
240 | */ |
241 | thread_group_cputime(tsk, &sum); | |
71107445 | 242 | update_gt_cputime(&cputimer->cputime_atomic, &sum); |
1018016c JL |
243 | |
244 | /* | |
245 | * We're setting cputimer->running without a lock. Ensure | |
246 | * this only gets written to in one operation. We set | |
247 | * running after update_gt_cputime() as a small optimization, | |
248 | * but barriers are not required because update_gt_cputime() | |
249 | * can handle concurrent updates. | |
250 | */ | |
d5c373eb | 251 | WRITE_ONCE(cputimer->running, true); |
1018016c | 252 | } |
71107445 | 253 | sample_cputime_atomic(times, &cputimer->cputime_atomic); |
4da94d49 PZ |
254 | } |
255 | ||
1da177e4 LT |
256 | /* |
257 | * Sample a process (thread group) clock for the given group_leader task. | |
e73d84e3 FW |
258 | * Must be called with task sighand lock held for safe while_each_thread() |
259 | * traversal. | |
1da177e4 | 260 | */ |
bb34d92f FM |
261 | static int cpu_clock_sample_group(const clockid_t which_clock, |
262 | struct task_struct *p, | |
55ccb616 | 263 | unsigned long long *sample) |
1da177e4 | 264 | { |
f06febc9 FM |
265 | struct task_cputime cputime; |
266 | ||
eccdaeaf | 267 | switch (CPUCLOCK_WHICH(which_clock)) { |
1da177e4 LT |
268 | default: |
269 | return -EINVAL; | |
270 | case CPUCLOCK_PROF: | |
c5f8d995 | 271 | thread_group_cputime(p, &cputime); |
55ccb616 | 272 | *sample = cputime_to_expires(cputime.utime + cputime.stime); |
1da177e4 LT |
273 | break; |
274 | case CPUCLOCK_VIRT: | |
c5f8d995 | 275 | thread_group_cputime(p, &cputime); |
55ccb616 | 276 | *sample = cputime_to_expires(cputime.utime); |
1da177e4 LT |
277 | break; |
278 | case CPUCLOCK_SCHED: | |
d670ec13 | 279 | thread_group_cputime(p, &cputime); |
55ccb616 | 280 | *sample = cputime.sum_exec_runtime; |
1da177e4 LT |
281 | break; |
282 | } | |
283 | return 0; | |
284 | } | |
285 | ||
33ab0fec FW |
286 | static int posix_cpu_clock_get_task(struct task_struct *tsk, |
287 | const clockid_t which_clock, | |
288 | struct timespec *tp) | |
289 | { | |
290 | int err = -EINVAL; | |
291 | unsigned long long rtn; | |
292 | ||
293 | if (CPUCLOCK_PERTHREAD(which_clock)) { | |
294 | if (same_thread_group(tsk, current)) | |
295 | err = cpu_clock_sample(which_clock, tsk, &rtn); | |
296 | } else { | |
50875788 | 297 | if (tsk == current || thread_group_leader(tsk)) |
33ab0fec | 298 | err = cpu_clock_sample_group(which_clock, tsk, &rtn); |
33ab0fec FW |
299 | } |
300 | ||
301 | if (!err) | |
302 | sample_to_timespec(which_clock, rtn, tp); | |
303 | ||
304 | return err; | |
305 | } | |
306 | ||
1da177e4 | 307 | |
bc2c8ea4 | 308 | static int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *tp) |
1da177e4 LT |
309 | { |
310 | const pid_t pid = CPUCLOCK_PID(which_clock); | |
33ab0fec | 311 | int err = -EINVAL; |
1da177e4 LT |
312 | |
313 | if (pid == 0) { | |
314 | /* | |
315 | * Special case constant value for our own clocks. | |
316 | * We don't have to do any lookup to find ourselves. | |
317 | */ | |
33ab0fec | 318 | err = posix_cpu_clock_get_task(current, which_clock, tp); |
1da177e4 LT |
319 | } else { |
320 | /* | |
321 | * Find the given PID, and validate that the caller | |
322 | * should be able to see it. | |
323 | */ | |
324 | struct task_struct *p; | |
1f2ea083 | 325 | rcu_read_lock(); |
8dc86af0 | 326 | p = find_task_by_vpid(pid); |
33ab0fec FW |
327 | if (p) |
328 | err = posix_cpu_clock_get_task(p, which_clock, tp); | |
1f2ea083 | 329 | rcu_read_unlock(); |
1da177e4 LT |
330 | } |
331 | ||
33ab0fec | 332 | return err; |
1da177e4 LT |
333 | } |
334 | ||
1da177e4 LT |
335 | /* |
336 | * Validate the clockid_t for a new CPU-clock timer, and initialize the timer. | |
ba5ea951 SG |
337 | * This is called from sys_timer_create() and do_cpu_nanosleep() with the |
338 | * new timer already all-zeros initialized. | |
1da177e4 | 339 | */ |
bc2c8ea4 | 340 | static int posix_cpu_timer_create(struct k_itimer *new_timer) |
1da177e4 LT |
341 | { |
342 | int ret = 0; | |
343 | const pid_t pid = CPUCLOCK_PID(new_timer->it_clock); | |
344 | struct task_struct *p; | |
345 | ||
346 | if (CPUCLOCK_WHICH(new_timer->it_clock) >= CPUCLOCK_MAX) | |
347 | return -EINVAL; | |
348 | ||
349 | INIT_LIST_HEAD(&new_timer->it.cpu.entry); | |
1da177e4 | 350 | |
c0deae8c | 351 | rcu_read_lock(); |
1da177e4 LT |
352 | if (CPUCLOCK_PERTHREAD(new_timer->it_clock)) { |
353 | if (pid == 0) { | |
354 | p = current; | |
355 | } else { | |
8dc86af0 | 356 | p = find_task_by_vpid(pid); |
bac0abd6 | 357 | if (p && !same_thread_group(p, current)) |
1da177e4 LT |
358 | p = NULL; |
359 | } | |
360 | } else { | |
361 | if (pid == 0) { | |
362 | p = current->group_leader; | |
363 | } else { | |
8dc86af0 | 364 | p = find_task_by_vpid(pid); |
c0deae8c | 365 | if (p && !has_group_leader_pid(p)) |
1da177e4 LT |
366 | p = NULL; |
367 | } | |
368 | } | |
369 | new_timer->it.cpu.task = p; | |
370 | if (p) { | |
371 | get_task_struct(p); | |
372 | } else { | |
373 | ret = -EINVAL; | |
374 | } | |
c0deae8c | 375 | rcu_read_unlock(); |
1da177e4 LT |
376 | |
377 | return ret; | |
378 | } | |
379 | ||
380 | /* | |
381 | * Clean up a CPU-clock timer that is about to be destroyed. | |
382 | * This is called from timer deletion with the timer already locked. | |
383 | * If we return TIMER_RETRY, it's necessary to release the timer's lock | |
384 | * and try again. (This happens when the timer is in the middle of firing.) | |
385 | */ | |
bc2c8ea4 | 386 | static int posix_cpu_timer_del(struct k_itimer *timer) |
1da177e4 | 387 | { |
108150ea | 388 | int ret = 0; |
3d7a1427 FW |
389 | unsigned long flags; |
390 | struct sighand_struct *sighand; | |
391 | struct task_struct *p = timer->it.cpu.task; | |
1da177e4 | 392 | |
a3222f88 | 393 | WARN_ON_ONCE(p == NULL); |
108150ea | 394 | |
3d7a1427 FW |
395 | /* |
396 | * Protect against sighand release/switch in exit/exec and process/ | |
397 | * thread timer list entry concurrent read/writes. | |
398 | */ | |
399 | sighand = lock_task_sighand(p, &flags); | |
400 | if (unlikely(sighand == NULL)) { | |
a3222f88 FW |
401 | /* |
402 | * We raced with the reaping of the task. | |
403 | * The deletion should have cleared us off the list. | |
404 | */ | |
531f64fd | 405 | WARN_ON_ONCE(!list_empty(&timer->it.cpu.entry)); |
a3222f88 | 406 | } else { |
a3222f88 FW |
407 | if (timer->it.cpu.firing) |
408 | ret = TIMER_RETRY; | |
409 | else | |
410 | list_del(&timer->it.cpu.entry); | |
3d7a1427 FW |
411 | |
412 | unlock_task_sighand(p, &flags); | |
1da177e4 | 413 | } |
a3222f88 FW |
414 | |
415 | if (!ret) | |
416 | put_task_struct(p); | |
1da177e4 | 417 | |
108150ea | 418 | return ret; |
1da177e4 LT |
419 | } |
420 | ||
af82eb3c | 421 | static void cleanup_timers_list(struct list_head *head) |
1a7fa510 FW |
422 | { |
423 | struct cpu_timer_list *timer, *next; | |
424 | ||
a0b2062b | 425 | list_for_each_entry_safe(timer, next, head, entry) |
1a7fa510 | 426 | list_del_init(&timer->entry); |
1a7fa510 FW |
427 | } |
428 | ||
1da177e4 LT |
429 | /* |
430 | * Clean out CPU timers still ticking when a thread exited. The task | |
431 | * pointer is cleared, and the expiry time is replaced with the residual | |
432 | * time for later timer_gettime calls to return. | |
433 | * This must be called with the siglock held. | |
434 | */ | |
af82eb3c | 435 | static void cleanup_timers(struct list_head *head) |
1da177e4 | 436 | { |
af82eb3c FW |
437 | cleanup_timers_list(head); |
438 | cleanup_timers_list(++head); | |
439 | cleanup_timers_list(++head); | |
1da177e4 LT |
440 | } |
441 | ||
442 | /* | |
443 | * These are both called with the siglock held, when the current thread | |
444 | * is being reaped. When the final (leader) thread in the group is reaped, | |
445 | * posix_cpu_timers_exit_group will be called after posix_cpu_timers_exit. | |
446 | */ | |
447 | void posix_cpu_timers_exit(struct task_struct *tsk) | |
448 | { | |
af82eb3c | 449 | cleanup_timers(tsk->cpu_timers); |
1da177e4 LT |
450 | } |
451 | void posix_cpu_timers_exit_group(struct task_struct *tsk) | |
452 | { | |
af82eb3c | 453 | cleanup_timers(tsk->signal->cpu_timers); |
1da177e4 LT |
454 | } |
455 | ||
d1e3b6d1 SG |
456 | static inline int expires_gt(cputime_t expires, cputime_t new_exp) |
457 | { | |
64861634 | 458 | return expires == 0 || expires > new_exp; |
d1e3b6d1 SG |
459 | } |
460 | ||
1da177e4 LT |
461 | /* |
462 | * Insert the timer on the appropriate list before any timers that | |
e73d84e3 | 463 | * expire later. This must be called with the sighand lock held. |
1da177e4 | 464 | */ |
5eb9aa64 | 465 | static void arm_timer(struct k_itimer *timer) |
1da177e4 LT |
466 | { |
467 | struct task_struct *p = timer->it.cpu.task; | |
468 | struct list_head *head, *listpos; | |
5eb9aa64 | 469 | struct task_cputime *cputime_expires; |
1da177e4 LT |
470 | struct cpu_timer_list *const nt = &timer->it.cpu; |
471 | struct cpu_timer_list *next; | |
1da177e4 | 472 | |
5eb9aa64 SG |
473 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { |
474 | head = p->cpu_timers; | |
475 | cputime_expires = &p->cputime_expires; | |
476 | } else { | |
477 | head = p->signal->cpu_timers; | |
478 | cputime_expires = &p->signal->cputime_expires; | |
479 | } | |
1da177e4 LT |
480 | head += CPUCLOCK_WHICH(timer->it_clock); |
481 | ||
1da177e4 | 482 | listpos = head; |
5eb9aa64 | 483 | list_for_each_entry(next, head, entry) { |
55ccb616 | 484 | if (nt->expires < next->expires) |
5eb9aa64 SG |
485 | break; |
486 | listpos = &next->entry; | |
1da177e4 LT |
487 | } |
488 | list_add(&nt->entry, listpos); | |
489 | ||
490 | if (listpos == head) { | |
55ccb616 | 491 | unsigned long long exp = nt->expires; |
5eb9aa64 | 492 | |
1da177e4 | 493 | /* |
5eb9aa64 SG |
494 | * We are the new earliest-expiring POSIX 1.b timer, hence |
495 | * need to update expiration cache. Take into account that | |
496 | * for process timers we share expiration cache with itimers | |
497 | * and RLIMIT_CPU and for thread timers with RLIMIT_RTTIME. | |
1da177e4 LT |
498 | */ |
499 | ||
5eb9aa64 SG |
500 | switch (CPUCLOCK_WHICH(timer->it_clock)) { |
501 | case CPUCLOCK_PROF: | |
55ccb616 FW |
502 | if (expires_gt(cputime_expires->prof_exp, expires_to_cputime(exp))) |
503 | cputime_expires->prof_exp = expires_to_cputime(exp); | |
5eb9aa64 SG |
504 | break; |
505 | case CPUCLOCK_VIRT: | |
55ccb616 FW |
506 | if (expires_gt(cputime_expires->virt_exp, expires_to_cputime(exp))) |
507 | cputime_expires->virt_exp = expires_to_cputime(exp); | |
5eb9aa64 SG |
508 | break; |
509 | case CPUCLOCK_SCHED: | |
510 | if (cputime_expires->sched_exp == 0 || | |
55ccb616 FW |
511 | cputime_expires->sched_exp > exp) |
512 | cputime_expires->sched_exp = exp; | |
5eb9aa64 | 513 | break; |
1da177e4 | 514 | } |
b7878300 FW |
515 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) |
516 | tick_dep_set_task(p, TICK_DEP_BIT_POSIX_TIMER); | |
517 | else | |
518 | tick_dep_set_signal(p->signal, TICK_DEP_BIT_POSIX_TIMER); | |
1da177e4 | 519 | } |
1da177e4 LT |
520 | } |
521 | ||
522 | /* | |
523 | * The timer is locked, fire it and arrange for its reload. | |
524 | */ | |
525 | static void cpu_timer_fire(struct k_itimer *timer) | |
526 | { | |
1f169f84 SG |
527 | if ((timer->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE) { |
528 | /* | |
529 | * User don't want any signal. | |
530 | */ | |
55ccb616 | 531 | timer->it.cpu.expires = 0; |
1f169f84 | 532 | } else if (unlikely(timer->sigq == NULL)) { |
1da177e4 LT |
533 | /* |
534 | * This a special case for clock_nanosleep, | |
535 | * not a normal timer from sys_timer_create. | |
536 | */ | |
537 | wake_up_process(timer->it_process); | |
55ccb616 FW |
538 | timer->it.cpu.expires = 0; |
539 | } else if (timer->it.cpu.incr == 0) { | |
1da177e4 LT |
540 | /* |
541 | * One-shot timer. Clear it as soon as it's fired. | |
542 | */ | |
543 | posix_timer_event(timer, 0); | |
55ccb616 | 544 | timer->it.cpu.expires = 0; |
1da177e4 LT |
545 | } else if (posix_timer_event(timer, ++timer->it_requeue_pending)) { |
546 | /* | |
547 | * The signal did not get queued because the signal | |
548 | * was ignored, so we won't get any callback to | |
549 | * reload the timer. But we need to keep it | |
550 | * ticking in case the signal is deliverable next time. | |
551 | */ | |
552 | posix_cpu_timer_schedule(timer); | |
553 | } | |
554 | } | |
555 | ||
3997ad31 PZ |
556 | /* |
557 | * Sample a process (thread group) timer for the given group_leader task. | |
e73d84e3 FW |
558 | * Must be called with task sighand lock held for safe while_each_thread() |
559 | * traversal. | |
3997ad31 PZ |
560 | */ |
561 | static int cpu_timer_sample_group(const clockid_t which_clock, | |
562 | struct task_struct *p, | |
55ccb616 | 563 | unsigned long long *sample) |
3997ad31 PZ |
564 | { |
565 | struct task_cputime cputime; | |
566 | ||
567 | thread_group_cputimer(p, &cputime); | |
568 | switch (CPUCLOCK_WHICH(which_clock)) { | |
569 | default: | |
570 | return -EINVAL; | |
571 | case CPUCLOCK_PROF: | |
55ccb616 | 572 | *sample = cputime_to_expires(cputime.utime + cputime.stime); |
3997ad31 PZ |
573 | break; |
574 | case CPUCLOCK_VIRT: | |
55ccb616 | 575 | *sample = cputime_to_expires(cputime.utime); |
3997ad31 PZ |
576 | break; |
577 | case CPUCLOCK_SCHED: | |
23cfa361 | 578 | *sample = cputime.sum_exec_runtime; |
3997ad31 PZ |
579 | break; |
580 | } | |
581 | return 0; | |
582 | } | |
583 | ||
1da177e4 LT |
584 | /* |
585 | * Guts of sys_timer_settime for CPU timers. | |
586 | * This is called with the timer locked and interrupts disabled. | |
587 | * If we return TIMER_RETRY, it's necessary to release the timer's lock | |
588 | * and try again. (This happens when the timer is in the middle of firing.) | |
589 | */ | |
e73d84e3 | 590 | static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags, |
bc2c8ea4 | 591 | struct itimerspec *new, struct itimerspec *old) |
1da177e4 | 592 | { |
e73d84e3 FW |
593 | unsigned long flags; |
594 | struct sighand_struct *sighand; | |
1da177e4 | 595 | struct task_struct *p = timer->it.cpu.task; |
55ccb616 | 596 | unsigned long long old_expires, new_expires, old_incr, val; |
1da177e4 LT |
597 | int ret; |
598 | ||
a3222f88 | 599 | WARN_ON_ONCE(p == NULL); |
1da177e4 LT |
600 | |
601 | new_expires = timespec_to_sample(timer->it_clock, &new->it_value); | |
602 | ||
1da177e4 | 603 | /* |
e73d84e3 FW |
604 | * Protect against sighand release/switch in exit/exec and p->cpu_timers |
605 | * and p->signal->cpu_timers read/write in arm_timer() | |
606 | */ | |
607 | sighand = lock_task_sighand(p, &flags); | |
608 | /* | |
609 | * If p has just been reaped, we can no | |
1da177e4 LT |
610 | * longer get any information about it at all. |
611 | */ | |
e73d84e3 | 612 | if (unlikely(sighand == NULL)) { |
1da177e4 LT |
613 | return -ESRCH; |
614 | } | |
615 | ||
616 | /* | |
617 | * Disarm any old timer after extracting its expiry time. | |
618 | */ | |
531f64fd | 619 | WARN_ON_ONCE(!irqs_disabled()); |
a69ac4a7 ON |
620 | |
621 | ret = 0; | |
ae1a78ee | 622 | old_incr = timer->it.cpu.incr; |
1da177e4 | 623 | old_expires = timer->it.cpu.expires; |
a69ac4a7 ON |
624 | if (unlikely(timer->it.cpu.firing)) { |
625 | timer->it.cpu.firing = -1; | |
626 | ret = TIMER_RETRY; | |
627 | } else | |
628 | list_del_init(&timer->it.cpu.entry); | |
1da177e4 LT |
629 | |
630 | /* | |
631 | * We need to sample the current value to convert the new | |
632 | * value from to relative and absolute, and to convert the | |
633 | * old value from absolute to relative. To set a process | |
634 | * timer, we need a sample to balance the thread expiry | |
635 | * times (in arm_timer). With an absolute time, we must | |
636 | * check if it's already passed. In short, we need a sample. | |
637 | */ | |
638 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
639 | cpu_clock_sample(timer->it_clock, p, &val); | |
640 | } else { | |
3997ad31 | 641 | cpu_timer_sample_group(timer->it_clock, p, &val); |
1da177e4 LT |
642 | } |
643 | ||
644 | if (old) { | |
55ccb616 | 645 | if (old_expires == 0) { |
1da177e4 LT |
646 | old->it_value.tv_sec = 0; |
647 | old->it_value.tv_nsec = 0; | |
648 | } else { | |
649 | /* | |
650 | * Update the timer in case it has | |
651 | * overrun already. If it has, | |
652 | * we'll report it as having overrun | |
653 | * and with the next reloaded timer | |
654 | * already ticking, though we are | |
655 | * swallowing that pending | |
656 | * notification here to install the | |
657 | * new setting. | |
658 | */ | |
659 | bump_cpu_timer(timer, val); | |
55ccb616 FW |
660 | if (val < timer->it.cpu.expires) { |
661 | old_expires = timer->it.cpu.expires - val; | |
1da177e4 LT |
662 | sample_to_timespec(timer->it_clock, |
663 | old_expires, | |
664 | &old->it_value); | |
665 | } else { | |
666 | old->it_value.tv_nsec = 1; | |
667 | old->it_value.tv_sec = 0; | |
668 | } | |
669 | } | |
670 | } | |
671 | ||
a69ac4a7 | 672 | if (unlikely(ret)) { |
1da177e4 LT |
673 | /* |
674 | * We are colliding with the timer actually firing. | |
675 | * Punt after filling in the timer's old value, and | |
676 | * disable this firing since we are already reporting | |
677 | * it as an overrun (thanks to bump_cpu_timer above). | |
678 | */ | |
e73d84e3 | 679 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
680 | goto out; |
681 | } | |
682 | ||
e73d84e3 | 683 | if (new_expires != 0 && !(timer_flags & TIMER_ABSTIME)) { |
55ccb616 | 684 | new_expires += val; |
1da177e4 LT |
685 | } |
686 | ||
687 | /* | |
688 | * Install the new expiry time (or zero). | |
689 | * For a timer with no notification action, we don't actually | |
690 | * arm the timer (we'll just fake it for timer_gettime). | |
691 | */ | |
692 | timer->it.cpu.expires = new_expires; | |
55ccb616 | 693 | if (new_expires != 0 && val < new_expires) { |
5eb9aa64 | 694 | arm_timer(timer); |
1da177e4 LT |
695 | } |
696 | ||
e73d84e3 | 697 | unlock_task_sighand(p, &flags); |
1da177e4 LT |
698 | /* |
699 | * Install the new reload setting, and | |
700 | * set up the signal and overrun bookkeeping. | |
701 | */ | |
702 | timer->it.cpu.incr = timespec_to_sample(timer->it_clock, | |
703 | &new->it_interval); | |
704 | ||
705 | /* | |
706 | * This acts as a modification timestamp for the timer, | |
707 | * so any automatic reload attempt will punt on seeing | |
708 | * that we have reset the timer manually. | |
709 | */ | |
710 | timer->it_requeue_pending = (timer->it_requeue_pending + 2) & | |
711 | ~REQUEUE_PENDING; | |
712 | timer->it_overrun_last = 0; | |
713 | timer->it_overrun = -1; | |
714 | ||
55ccb616 | 715 | if (new_expires != 0 && !(val < new_expires)) { |
1da177e4 LT |
716 | /* |
717 | * The designated time already passed, so we notify | |
718 | * immediately, even if the thread never runs to | |
719 | * accumulate more time on this clock. | |
720 | */ | |
721 | cpu_timer_fire(timer); | |
722 | } | |
723 | ||
724 | ret = 0; | |
725 | out: | |
726 | if (old) { | |
727 | sample_to_timespec(timer->it_clock, | |
ae1a78ee | 728 | old_incr, &old->it_interval); |
1da177e4 | 729 | } |
b7878300 | 730 | |
1da177e4 LT |
731 | return ret; |
732 | } | |
733 | ||
bc2c8ea4 | 734 | static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp) |
1da177e4 | 735 | { |
55ccb616 | 736 | unsigned long long now; |
1da177e4 | 737 | struct task_struct *p = timer->it.cpu.task; |
1da177e4 | 738 | |
a3222f88 FW |
739 | WARN_ON_ONCE(p == NULL); |
740 | ||
1da177e4 LT |
741 | /* |
742 | * Easy part: convert the reload time. | |
743 | */ | |
744 | sample_to_timespec(timer->it_clock, | |
745 | timer->it.cpu.incr, &itp->it_interval); | |
746 | ||
55ccb616 | 747 | if (timer->it.cpu.expires == 0) { /* Timer not armed at all. */ |
1da177e4 LT |
748 | itp->it_value.tv_sec = itp->it_value.tv_nsec = 0; |
749 | return; | |
750 | } | |
751 | ||
1da177e4 LT |
752 | /* |
753 | * Sample the clock to take the difference with the expiry time. | |
754 | */ | |
755 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
756 | cpu_clock_sample(timer->it_clock, p, &now); | |
1da177e4 | 757 | } else { |
e73d84e3 FW |
758 | struct sighand_struct *sighand; |
759 | unsigned long flags; | |
760 | ||
761 | /* | |
762 | * Protect against sighand release/switch in exit/exec and | |
763 | * also make timer sampling safe if it ends up calling | |
764 | * thread_group_cputime(). | |
765 | */ | |
766 | sighand = lock_task_sighand(p, &flags); | |
767 | if (unlikely(sighand == NULL)) { | |
1da177e4 LT |
768 | /* |
769 | * The process has been reaped. | |
770 | * We can't even collect a sample any more. | |
771 | * Call the timer disarmed, nothing else to do. | |
772 | */ | |
55ccb616 | 773 | timer->it.cpu.expires = 0; |
a3222f88 FW |
774 | sample_to_timespec(timer->it_clock, timer->it.cpu.expires, |
775 | &itp->it_value); | |
2c13ce8f | 776 | return; |
1da177e4 | 777 | } else { |
3997ad31 | 778 | cpu_timer_sample_group(timer->it_clock, p, &now); |
e73d84e3 | 779 | unlock_task_sighand(p, &flags); |
1da177e4 | 780 | } |
1da177e4 LT |
781 | } |
782 | ||
55ccb616 | 783 | if (now < timer->it.cpu.expires) { |
1da177e4 | 784 | sample_to_timespec(timer->it_clock, |
55ccb616 | 785 | timer->it.cpu.expires - now, |
1da177e4 LT |
786 | &itp->it_value); |
787 | } else { | |
788 | /* | |
789 | * The timer should have expired already, but the firing | |
790 | * hasn't taken place yet. Say it's just about to expire. | |
791 | */ | |
792 | itp->it_value.tv_nsec = 1; | |
793 | itp->it_value.tv_sec = 0; | |
794 | } | |
795 | } | |
796 | ||
2473f3e7 FW |
797 | static unsigned long long |
798 | check_timers_list(struct list_head *timers, | |
799 | struct list_head *firing, | |
800 | unsigned long long curr) | |
801 | { | |
802 | int maxfire = 20; | |
803 | ||
804 | while (!list_empty(timers)) { | |
805 | struct cpu_timer_list *t; | |
806 | ||
807 | t = list_first_entry(timers, struct cpu_timer_list, entry); | |
808 | ||
809 | if (!--maxfire || curr < t->expires) | |
810 | return t->expires; | |
811 | ||
812 | t->firing = 1; | |
813 | list_move_tail(&t->entry, firing); | |
814 | } | |
815 | ||
816 | return 0; | |
817 | } | |
818 | ||
1da177e4 LT |
819 | /* |
820 | * Check for any per-thread CPU timers that have fired and move them off | |
821 | * the tsk->cpu_timers[N] list onto the firing list. Here we update the | |
822 | * tsk->it_*_expires values to reflect the remaining thread CPU timers. | |
823 | */ | |
824 | static void check_thread_timers(struct task_struct *tsk, | |
825 | struct list_head *firing) | |
826 | { | |
827 | struct list_head *timers = tsk->cpu_timers; | |
78f2c7db | 828 | struct signal_struct *const sig = tsk->signal; |
2473f3e7 FW |
829 | struct task_cputime *tsk_expires = &tsk->cputime_expires; |
830 | unsigned long long expires; | |
d4bb5274 | 831 | unsigned long soft; |
1da177e4 | 832 | |
934715a1 JL |
833 | /* |
834 | * If cputime_expires is zero, then there are no active | |
835 | * per thread CPU timers. | |
836 | */ | |
837 | if (task_cputime_zero(&tsk->cputime_expires)) | |
838 | return; | |
839 | ||
2473f3e7 FW |
840 | expires = check_timers_list(timers, firing, prof_ticks(tsk)); |
841 | tsk_expires->prof_exp = expires_to_cputime(expires); | |
1da177e4 | 842 | |
2473f3e7 FW |
843 | expires = check_timers_list(++timers, firing, virt_ticks(tsk)); |
844 | tsk_expires->virt_exp = expires_to_cputime(expires); | |
1da177e4 | 845 | |
2473f3e7 FW |
846 | tsk_expires->sched_exp = check_timers_list(++timers, firing, |
847 | tsk->se.sum_exec_runtime); | |
78f2c7db PZ |
848 | |
849 | /* | |
850 | * Check for the special case thread timers. | |
851 | */ | |
316c1608 | 852 | soft = READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur); |
d4bb5274 | 853 | if (soft != RLIM_INFINITY) { |
78d7d407 | 854 | unsigned long hard = |
316c1608 | 855 | READ_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max); |
78f2c7db | 856 | |
5a52dd50 PZ |
857 | if (hard != RLIM_INFINITY && |
858 | tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) { | |
78f2c7db PZ |
859 | /* |
860 | * At the hard limit, we just die. | |
861 | * No need to calculate anything else now. | |
862 | */ | |
863 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); | |
864 | return; | |
865 | } | |
d4bb5274 | 866 | if (tsk->rt.timeout > DIV_ROUND_UP(soft, USEC_PER_SEC/HZ)) { |
78f2c7db PZ |
867 | /* |
868 | * At the soft limit, send a SIGXCPU every second. | |
869 | */ | |
d4bb5274 JS |
870 | if (soft < hard) { |
871 | soft += USEC_PER_SEC; | |
872 | sig->rlim[RLIMIT_RTTIME].rlim_cur = soft; | |
78f2c7db | 873 | } |
81d50bb2 HS |
874 | printk(KERN_INFO |
875 | "RT Watchdog Timeout: %s[%d]\n", | |
876 | tsk->comm, task_pid_nr(tsk)); | |
78f2c7db PZ |
877 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); |
878 | } | |
879 | } | |
b7878300 FW |
880 | if (task_cputime_zero(tsk_expires)) |
881 | tick_dep_clear_task(tsk, TICK_DEP_BIT_POSIX_TIMER); | |
1da177e4 LT |
882 | } |
883 | ||
1018016c | 884 | static inline void stop_process_timers(struct signal_struct *sig) |
3fccfd67 | 885 | { |
15365c10 | 886 | struct thread_group_cputimer *cputimer = &sig->cputimer; |
3fccfd67 | 887 | |
1018016c | 888 | /* Turn off cputimer->running. This is done without locking. */ |
d5c373eb | 889 | WRITE_ONCE(cputimer->running, false); |
b7878300 | 890 | tick_dep_clear_signal(sig, TICK_DEP_BIT_POSIX_TIMER); |
3fccfd67 PZ |
891 | } |
892 | ||
8356b5f9 SG |
893 | static u32 onecputick; |
894 | ||
42c4ab41 | 895 | static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, |
55ccb616 FW |
896 | unsigned long long *expires, |
897 | unsigned long long cur_time, int signo) | |
42c4ab41 | 898 | { |
64861634 | 899 | if (!it->expires) |
42c4ab41 SG |
900 | return; |
901 | ||
64861634 MS |
902 | if (cur_time >= it->expires) { |
903 | if (it->incr) { | |
904 | it->expires += it->incr; | |
8356b5f9 SG |
905 | it->error += it->incr_error; |
906 | if (it->error >= onecputick) { | |
64861634 | 907 | it->expires -= cputime_one_jiffy; |
8356b5f9 SG |
908 | it->error -= onecputick; |
909 | } | |
3f0a525e | 910 | } else { |
64861634 | 911 | it->expires = 0; |
3f0a525e | 912 | } |
42c4ab41 | 913 | |
3f0a525e XG |
914 | trace_itimer_expire(signo == SIGPROF ? |
915 | ITIMER_PROF : ITIMER_VIRTUAL, | |
916 | tsk->signal->leader_pid, cur_time); | |
42c4ab41 SG |
917 | __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); |
918 | } | |
919 | ||
64861634 | 920 | if (it->expires && (!*expires || it->expires < *expires)) { |
42c4ab41 SG |
921 | *expires = it->expires; |
922 | } | |
923 | } | |
924 | ||
1da177e4 LT |
925 | /* |
926 | * Check for any per-thread CPU timers that have fired and move them | |
927 | * off the tsk->*_timers list onto the firing list. Per-thread timers | |
928 | * have already been taken off. | |
929 | */ | |
930 | static void check_process_timers(struct task_struct *tsk, | |
931 | struct list_head *firing) | |
932 | { | |
933 | struct signal_struct *const sig = tsk->signal; | |
55ccb616 | 934 | unsigned long long utime, ptime, virt_expires, prof_expires; |
41b86e9c | 935 | unsigned long long sum_sched_runtime, sched_expires; |
1da177e4 | 936 | struct list_head *timers = sig->cpu_timers; |
f06febc9 | 937 | struct task_cputime cputime; |
d4bb5274 | 938 | unsigned long soft; |
1da177e4 | 939 | |
934715a1 JL |
940 | /* |
941 | * If cputimer is not running, then there are no active | |
942 | * process wide timers (POSIX 1.b, itimers, RLIMIT_CPU). | |
943 | */ | |
944 | if (!READ_ONCE(tsk->signal->cputimer.running)) | |
945 | return; | |
946 | ||
c8d75aa4 JL |
947 | /* |
948 | * Signify that a thread is checking for process timers. | |
949 | * Write access to this field is protected by the sighand lock. | |
950 | */ | |
951 | sig->cputimer.checking_timer = true; | |
952 | ||
1da177e4 LT |
953 | /* |
954 | * Collect the current process totals. | |
955 | */ | |
4cd4c1b4 | 956 | thread_group_cputimer(tsk, &cputime); |
55ccb616 FW |
957 | utime = cputime_to_expires(cputime.utime); |
958 | ptime = utime + cputime_to_expires(cputime.stime); | |
f06febc9 | 959 | sum_sched_runtime = cputime.sum_exec_runtime; |
1da177e4 | 960 | |
2473f3e7 FW |
961 | prof_expires = check_timers_list(timers, firing, ptime); |
962 | virt_expires = check_timers_list(++timers, firing, utime); | |
963 | sched_expires = check_timers_list(++timers, firing, sum_sched_runtime); | |
1da177e4 LT |
964 | |
965 | /* | |
966 | * Check for the special case process timers. | |
967 | */ | |
42c4ab41 SG |
968 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime, |
969 | SIGPROF); | |
970 | check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime, | |
971 | SIGVTALRM); | |
316c1608 | 972 | soft = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur); |
d4bb5274 | 973 | if (soft != RLIM_INFINITY) { |
1da177e4 | 974 | unsigned long psecs = cputime_to_secs(ptime); |
78d7d407 | 975 | unsigned long hard = |
316c1608 | 976 | READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_max); |
1da177e4 | 977 | cputime_t x; |
d4bb5274 | 978 | if (psecs >= hard) { |
1da177e4 LT |
979 | /* |
980 | * At the hard limit, we just die. | |
981 | * No need to calculate anything else now. | |
982 | */ | |
983 | __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk); | |
984 | return; | |
985 | } | |
d4bb5274 | 986 | if (psecs >= soft) { |
1da177e4 LT |
987 | /* |
988 | * At the soft limit, send a SIGXCPU every second. | |
989 | */ | |
990 | __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); | |
d4bb5274 JS |
991 | if (soft < hard) { |
992 | soft++; | |
993 | sig->rlim[RLIMIT_CPU].rlim_cur = soft; | |
1da177e4 LT |
994 | } |
995 | } | |
d4bb5274 | 996 | x = secs_to_cputime(soft); |
64861634 | 997 | if (!prof_expires || x < prof_expires) { |
1da177e4 LT |
998 | prof_expires = x; |
999 | } | |
1000 | } | |
1001 | ||
55ccb616 FW |
1002 | sig->cputime_expires.prof_exp = expires_to_cputime(prof_expires); |
1003 | sig->cputime_expires.virt_exp = expires_to_cputime(virt_expires); | |
29f87b79 SG |
1004 | sig->cputime_expires.sched_exp = sched_expires; |
1005 | if (task_cputime_zero(&sig->cputime_expires)) | |
1006 | stop_process_timers(sig); | |
c8d75aa4 JL |
1007 | |
1008 | sig->cputimer.checking_timer = false; | |
1da177e4 LT |
1009 | } |
1010 | ||
1011 | /* | |
1012 | * This is called from the signal code (via do_schedule_next_timer) | |
1013 | * when the last timer signal was delivered and we have to reload the timer. | |
1014 | */ | |
1015 | void posix_cpu_timer_schedule(struct k_itimer *timer) | |
1016 | { | |
e73d84e3 FW |
1017 | struct sighand_struct *sighand; |
1018 | unsigned long flags; | |
1da177e4 | 1019 | struct task_struct *p = timer->it.cpu.task; |
55ccb616 | 1020 | unsigned long long now; |
1da177e4 | 1021 | |
a3222f88 | 1022 | WARN_ON_ONCE(p == NULL); |
1da177e4 LT |
1023 | |
1024 | /* | |
1025 | * Fetch the current sample and update the timer's expiry time. | |
1026 | */ | |
1027 | if (CPUCLOCK_PERTHREAD(timer->it_clock)) { | |
1028 | cpu_clock_sample(timer->it_clock, p, &now); | |
1029 | bump_cpu_timer(timer, now); | |
724a3713 | 1030 | if (unlikely(p->exit_state)) |
708f430d | 1031 | goto out; |
724a3713 | 1032 | |
e73d84e3 FW |
1033 | /* Protect timer list r/w in arm_timer() */ |
1034 | sighand = lock_task_sighand(p, &flags); | |
1035 | if (!sighand) | |
1036 | goto out; | |
1da177e4 | 1037 | } else { |
e73d84e3 FW |
1038 | /* |
1039 | * Protect arm_timer() and timer sampling in case of call to | |
1040 | * thread_group_cputime(). | |
1041 | */ | |
1042 | sighand = lock_task_sighand(p, &flags); | |
1043 | if (unlikely(sighand == NULL)) { | |
1da177e4 LT |
1044 | /* |
1045 | * The process has been reaped. | |
1046 | * We can't even collect a sample any more. | |
1047 | */ | |
55ccb616 | 1048 | timer->it.cpu.expires = 0; |
c925077c | 1049 | goto out; |
1da177e4 | 1050 | } else if (unlikely(p->exit_state) && thread_group_empty(p)) { |
e73d84e3 | 1051 | unlock_task_sighand(p, &flags); |
d430b917 | 1052 | /* Optimizations: if the process is dying, no need to rearm */ |
c925077c | 1053 | goto out; |
1da177e4 | 1054 | } |
3997ad31 | 1055 | cpu_timer_sample_group(timer->it_clock, p, &now); |
1da177e4 | 1056 | bump_cpu_timer(timer, now); |
e73d84e3 | 1057 | /* Leave the sighand locked for the call below. */ |
1da177e4 LT |
1058 | } |
1059 | ||
1060 | /* | |
1061 | * Now re-arm for the new expiry time. | |
1062 | */ | |
531f64fd | 1063 | WARN_ON_ONCE(!irqs_disabled()); |
5eb9aa64 | 1064 | arm_timer(timer); |
e73d84e3 | 1065 | unlock_task_sighand(p, &flags); |
708f430d RM |
1066 | |
1067 | out: | |
1068 | timer->it_overrun_last = timer->it_overrun; | |
1069 | timer->it_overrun = -1; | |
1070 | ++timer->it_requeue_pending; | |
1da177e4 LT |
1071 | } |
1072 | ||
f06febc9 FM |
1073 | /** |
1074 | * task_cputime_expired - Compare two task_cputime entities. | |
1075 | * | |
1076 | * @sample: The task_cputime structure to be checked for expiration. | |
1077 | * @expires: Expiration times, against which @sample will be checked. | |
1078 | * | |
1079 | * Checks @sample against @expires to see if any field of @sample has expired. | |
1080 | * Returns true if any field of the former is greater than the corresponding | |
1081 | * field of the latter if the latter field is set. Otherwise returns false. | |
1082 | */ | |
1083 | static inline int task_cputime_expired(const struct task_cputime *sample, | |
1084 | const struct task_cputime *expires) | |
1085 | { | |
64861634 | 1086 | if (expires->utime && sample->utime >= expires->utime) |
f06febc9 | 1087 | return 1; |
64861634 | 1088 | if (expires->stime && sample->utime + sample->stime >= expires->stime) |
f06febc9 FM |
1089 | return 1; |
1090 | if (expires->sum_exec_runtime != 0 && | |
1091 | sample->sum_exec_runtime >= expires->sum_exec_runtime) | |
1092 | return 1; | |
1093 | return 0; | |
1094 | } | |
1095 | ||
1096 | /** | |
1097 | * fastpath_timer_check - POSIX CPU timers fast path. | |
1098 | * | |
1099 | * @tsk: The task (thread) being checked. | |
f06febc9 | 1100 | * |
bb34d92f FM |
1101 | * Check the task and thread group timers. If both are zero (there are no |
1102 | * timers set) return false. Otherwise snapshot the task and thread group | |
1103 | * timers and compare them with the corresponding expiration times. Return | |
1104 | * true if a timer has expired, else return false. | |
f06febc9 | 1105 | */ |
bb34d92f | 1106 | static inline int fastpath_timer_check(struct task_struct *tsk) |
f06febc9 | 1107 | { |
ad133ba3 | 1108 | struct signal_struct *sig; |
bb34d92f | 1109 | |
bb34d92f | 1110 | if (!task_cputime_zero(&tsk->cputime_expires)) { |
7c177d99 | 1111 | struct task_cputime task_sample; |
bb34d92f | 1112 | |
7c177d99 JL |
1113 | task_cputime(tsk, &task_sample.utime, &task_sample.stime); |
1114 | task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime; | |
bb34d92f FM |
1115 | if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) |
1116 | return 1; | |
1117 | } | |
ad133ba3 ON |
1118 | |
1119 | sig = tsk->signal; | |
c8d75aa4 JL |
1120 | /* |
1121 | * Check if thread group timers expired when the cputimer is | |
1122 | * running and no other thread in the group is already checking | |
1123 | * for thread group cputimers. These fields are read without the | |
1124 | * sighand lock. However, this is fine because this is meant to | |
1125 | * be a fastpath heuristic to determine whether we should try to | |
1126 | * acquire the sighand lock to check/handle timers. | |
1127 | * | |
1128 | * In the worst case scenario, if 'running' or 'checking_timer' gets | |
1129 | * set but the current thread doesn't see the change yet, we'll wait | |
1130 | * until the next thread in the group gets a scheduler interrupt to | |
1131 | * handle the timer. This isn't an issue in practice because these | |
1132 | * types of delays with signals actually getting sent are expected. | |
1133 | */ | |
1134 | if (READ_ONCE(sig->cputimer.running) && | |
1135 | !READ_ONCE(sig->cputimer.checking_timer)) { | |
bb34d92f FM |
1136 | struct task_cputime group_sample; |
1137 | ||
71107445 | 1138 | sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic); |
8d1f431c | 1139 | |
bb34d92f FM |
1140 | if (task_cputime_expired(&group_sample, &sig->cputime_expires)) |
1141 | return 1; | |
1142 | } | |
37bebc70 | 1143 | |
f55db609 | 1144 | return 0; |
f06febc9 FM |
1145 | } |
1146 | ||
1da177e4 LT |
1147 | /* |
1148 | * This is called from the timer interrupt handler. The irq handler has | |
1149 | * already updated our counts. We need to check if any timers fire now. | |
1150 | * Interrupts are disabled. | |
1151 | */ | |
1152 | void run_posix_cpu_timers(struct task_struct *tsk) | |
1153 | { | |
1154 | LIST_HEAD(firing); | |
1155 | struct k_itimer *timer, *next; | |
0bdd2ed4 | 1156 | unsigned long flags; |
1da177e4 | 1157 | |
531f64fd | 1158 | WARN_ON_ONCE(!irqs_disabled()); |
1da177e4 | 1159 | |
1da177e4 | 1160 | /* |
f06febc9 | 1161 | * The fast path checks that there are no expired thread or thread |
bb34d92f | 1162 | * group timers. If that's so, just return. |
1da177e4 | 1163 | */ |
bb34d92f | 1164 | if (!fastpath_timer_check(tsk)) |
f06febc9 | 1165 | return; |
5ce73a4a | 1166 | |
0bdd2ed4 ON |
1167 | if (!lock_task_sighand(tsk, &flags)) |
1168 | return; | |
bb34d92f FM |
1169 | /* |
1170 | * Here we take off tsk->signal->cpu_timers[N] and | |
1171 | * tsk->cpu_timers[N] all the timers that are firing, and | |
1172 | * put them on the firing list. | |
1173 | */ | |
1174 | check_thread_timers(tsk, &firing); | |
934715a1 JL |
1175 | |
1176 | check_process_timers(tsk, &firing); | |
1da177e4 | 1177 | |
bb34d92f FM |
1178 | /* |
1179 | * We must release these locks before taking any timer's lock. | |
1180 | * There is a potential race with timer deletion here, as the | |
1181 | * siglock now protects our private firing list. We have set | |
1182 | * the firing flag in each timer, so that a deletion attempt | |
1183 | * that gets the timer lock before we do will give it up and | |
1184 | * spin until we've taken care of that timer below. | |
1185 | */ | |
0bdd2ed4 | 1186 | unlock_task_sighand(tsk, &flags); |
1da177e4 LT |
1187 | |
1188 | /* | |
1189 | * Now that all the timers on our list have the firing flag, | |
25985edc | 1190 | * no one will touch their list entries but us. We'll take |
1da177e4 LT |
1191 | * each timer's lock before clearing its firing flag, so no |
1192 | * timer call will interfere. | |
1193 | */ | |
1194 | list_for_each_entry_safe(timer, next, &firing, it.cpu.entry) { | |
6e85c5ba HS |
1195 | int cpu_firing; |
1196 | ||
1da177e4 LT |
1197 | spin_lock(&timer->it_lock); |
1198 | list_del_init(&timer->it.cpu.entry); | |
6e85c5ba | 1199 | cpu_firing = timer->it.cpu.firing; |
1da177e4 LT |
1200 | timer->it.cpu.firing = 0; |
1201 | /* | |
1202 | * The firing flag is -1 if we collided with a reset | |
1203 | * of the timer, which already reported this | |
1204 | * almost-firing as an overrun. So don't generate an event. | |
1205 | */ | |
6e85c5ba | 1206 | if (likely(cpu_firing >= 0)) |
1da177e4 | 1207 | cpu_timer_fire(timer); |
1da177e4 LT |
1208 | spin_unlock(&timer->it_lock); |
1209 | } | |
1210 | } | |
1211 | ||
1212 | /* | |
f55db609 | 1213 | * Set one of the process-wide special case CPU timers or RLIMIT_CPU. |
f06febc9 | 1214 | * The tsk->sighand->siglock must be held by the caller. |
1da177e4 LT |
1215 | */ |
1216 | void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx, | |
1217 | cputime_t *newval, cputime_t *oldval) | |
1218 | { | |
55ccb616 | 1219 | unsigned long long now; |
1da177e4 | 1220 | |
531f64fd | 1221 | WARN_ON_ONCE(clock_idx == CPUCLOCK_SCHED); |
4cd4c1b4 | 1222 | cpu_timer_sample_group(clock_idx, tsk, &now); |
1da177e4 LT |
1223 | |
1224 | if (oldval) { | |
f55db609 SG |
1225 | /* |
1226 | * We are setting itimer. The *oldval is absolute and we update | |
1227 | * it to be relative, *newval argument is relative and we update | |
1228 | * it to be absolute. | |
1229 | */ | |
64861634 | 1230 | if (*oldval) { |
55ccb616 | 1231 | if (*oldval <= now) { |
1da177e4 | 1232 | /* Just about to fire. */ |
a42548a1 | 1233 | *oldval = cputime_one_jiffy; |
1da177e4 | 1234 | } else { |
55ccb616 | 1235 | *oldval -= now; |
1da177e4 LT |
1236 | } |
1237 | } | |
1238 | ||
64861634 | 1239 | if (!*newval) |
b7878300 | 1240 | return; |
55ccb616 | 1241 | *newval += now; |
1da177e4 LT |
1242 | } |
1243 | ||
1244 | /* | |
f55db609 SG |
1245 | * Update expiration cache if we are the earliest timer, or eventually |
1246 | * RLIMIT_CPU limit is earlier than prof_exp cpu timer expire. | |
1da177e4 | 1247 | */ |
f55db609 SG |
1248 | switch (clock_idx) { |
1249 | case CPUCLOCK_PROF: | |
1250 | if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval)) | |
f06febc9 | 1251 | tsk->signal->cputime_expires.prof_exp = *newval; |
f55db609 SG |
1252 | break; |
1253 | case CPUCLOCK_VIRT: | |
1254 | if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval)) | |
f06febc9 | 1255 | tsk->signal->cputime_expires.virt_exp = *newval; |
f55db609 | 1256 | break; |
1da177e4 | 1257 | } |
b7878300 FW |
1258 | |
1259 | tick_dep_set_signal(tsk->signal, TICK_DEP_BIT_POSIX_TIMER); | |
1da177e4 LT |
1260 | } |
1261 | ||
e4b76555 TA |
1262 | static int do_cpu_nanosleep(const clockid_t which_clock, int flags, |
1263 | struct timespec *rqtp, struct itimerspec *it) | |
1da177e4 | 1264 | { |
1da177e4 LT |
1265 | struct k_itimer timer; |
1266 | int error; | |
1267 | ||
1da177e4 LT |
1268 | /* |
1269 | * Set up a temporary timer and then wait for it to go off. | |
1270 | */ | |
1271 | memset(&timer, 0, sizeof timer); | |
1272 | spin_lock_init(&timer.it_lock); | |
1273 | timer.it_clock = which_clock; | |
1274 | timer.it_overrun = -1; | |
1275 | error = posix_cpu_timer_create(&timer); | |
1276 | timer.it_process = current; | |
1277 | if (!error) { | |
1da177e4 | 1278 | static struct itimerspec zero_it; |
e4b76555 TA |
1279 | |
1280 | memset(it, 0, sizeof *it); | |
1281 | it->it_value = *rqtp; | |
1da177e4 LT |
1282 | |
1283 | spin_lock_irq(&timer.it_lock); | |
e4b76555 | 1284 | error = posix_cpu_timer_set(&timer, flags, it, NULL); |
1da177e4 LT |
1285 | if (error) { |
1286 | spin_unlock_irq(&timer.it_lock); | |
1287 | return error; | |
1288 | } | |
1289 | ||
1290 | while (!signal_pending(current)) { | |
55ccb616 | 1291 | if (timer.it.cpu.expires == 0) { |
1da177e4 | 1292 | /* |
e6c42c29 SG |
1293 | * Our timer fired and was reset, below |
1294 | * deletion can not fail. | |
1da177e4 | 1295 | */ |
e6c42c29 | 1296 | posix_cpu_timer_del(&timer); |
1da177e4 LT |
1297 | spin_unlock_irq(&timer.it_lock); |
1298 | return 0; | |
1299 | } | |
1300 | ||
1301 | /* | |
1302 | * Block until cpu_timer_fire (or a signal) wakes us. | |
1303 | */ | |
1304 | __set_current_state(TASK_INTERRUPTIBLE); | |
1305 | spin_unlock_irq(&timer.it_lock); | |
1306 | schedule(); | |
1307 | spin_lock_irq(&timer.it_lock); | |
1308 | } | |
1309 | ||
1310 | /* | |
1311 | * We were interrupted by a signal. | |
1312 | */ | |
1313 | sample_to_timespec(which_clock, timer.it.cpu.expires, rqtp); | |
e6c42c29 SG |
1314 | error = posix_cpu_timer_set(&timer, 0, &zero_it, it); |
1315 | if (!error) { | |
1316 | /* | |
1317 | * Timer is now unarmed, deletion can not fail. | |
1318 | */ | |
1319 | posix_cpu_timer_del(&timer); | |
1320 | } | |
1da177e4 LT |
1321 | spin_unlock_irq(&timer.it_lock); |
1322 | ||
e6c42c29 SG |
1323 | while (error == TIMER_RETRY) { |
1324 | /* | |
1325 | * We need to handle case when timer was or is in the | |
1326 | * middle of firing. In other cases we already freed | |
1327 | * resources. | |
1328 | */ | |
1329 | spin_lock_irq(&timer.it_lock); | |
1330 | error = posix_cpu_timer_del(&timer); | |
1331 | spin_unlock_irq(&timer.it_lock); | |
1332 | } | |
1333 | ||
e4b76555 | 1334 | if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) { |
1da177e4 LT |
1335 | /* |
1336 | * It actually did fire already. | |
1337 | */ | |
1338 | return 0; | |
1339 | } | |
1340 | ||
e4b76555 TA |
1341 | error = -ERESTART_RESTARTBLOCK; |
1342 | } | |
1343 | ||
1344 | return error; | |
1345 | } | |
1346 | ||
bc2c8ea4 TG |
1347 | static long posix_cpu_nsleep_restart(struct restart_block *restart_block); |
1348 | ||
1349 | static int posix_cpu_nsleep(const clockid_t which_clock, int flags, | |
1350 | struct timespec *rqtp, struct timespec __user *rmtp) | |
e4b76555 | 1351 | { |
f56141e3 | 1352 | struct restart_block *restart_block = ¤t->restart_block; |
e4b76555 TA |
1353 | struct itimerspec it; |
1354 | int error; | |
1355 | ||
1356 | /* | |
1357 | * Diagnose required errors first. | |
1358 | */ | |
1359 | if (CPUCLOCK_PERTHREAD(which_clock) && | |
1360 | (CPUCLOCK_PID(which_clock) == 0 || | |
1361 | CPUCLOCK_PID(which_clock) == current->pid)) | |
1362 | return -EINVAL; | |
1363 | ||
1364 | error = do_cpu_nanosleep(which_clock, flags, rqtp, &it); | |
1365 | ||
1366 | if (error == -ERESTART_RESTARTBLOCK) { | |
1367 | ||
3751f9f2 | 1368 | if (flags & TIMER_ABSTIME) |
e4b76555 | 1369 | return -ERESTARTNOHAND; |
1da177e4 | 1370 | /* |
3751f9f2 TG |
1371 | * Report back to the user the time still remaining. |
1372 | */ | |
1373 | if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) | |
1da177e4 LT |
1374 | return -EFAULT; |
1375 | ||
1711ef38 | 1376 | restart_block->fn = posix_cpu_nsleep_restart; |
ab8177bc | 1377 | restart_block->nanosleep.clockid = which_clock; |
3751f9f2 TG |
1378 | restart_block->nanosleep.rmtp = rmtp; |
1379 | restart_block->nanosleep.expires = timespec_to_ns(rqtp); | |
1da177e4 | 1380 | } |
1da177e4 LT |
1381 | return error; |
1382 | } | |
1383 | ||
bc2c8ea4 | 1384 | static long posix_cpu_nsleep_restart(struct restart_block *restart_block) |
1da177e4 | 1385 | { |
ab8177bc | 1386 | clockid_t which_clock = restart_block->nanosleep.clockid; |
97735f25 | 1387 | struct timespec t; |
e4b76555 TA |
1388 | struct itimerspec it; |
1389 | int error; | |
97735f25 | 1390 | |
3751f9f2 | 1391 | t = ns_to_timespec(restart_block->nanosleep.expires); |
97735f25 | 1392 | |
e4b76555 TA |
1393 | error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it); |
1394 | ||
1395 | if (error == -ERESTART_RESTARTBLOCK) { | |
3751f9f2 | 1396 | struct timespec __user *rmtp = restart_block->nanosleep.rmtp; |
e4b76555 | 1397 | /* |
3751f9f2 TG |
1398 | * Report back to the user the time still remaining. |
1399 | */ | |
1400 | if (rmtp && copy_to_user(rmtp, &it.it_value, sizeof *rmtp)) | |
e4b76555 TA |
1401 | return -EFAULT; |
1402 | ||
3751f9f2 | 1403 | restart_block->nanosleep.expires = timespec_to_ns(&t); |
e4b76555 TA |
1404 | } |
1405 | return error; | |
1406 | ||
1da177e4 LT |
1407 | } |
1408 | ||
1da177e4 LT |
1409 | #define PROCESS_CLOCK MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED) |
1410 | #define THREAD_CLOCK MAKE_THREAD_CPUCLOCK(0, CPUCLOCK_SCHED) | |
1411 | ||
a924b04d TG |
1412 | static int process_cpu_clock_getres(const clockid_t which_clock, |
1413 | struct timespec *tp) | |
1da177e4 LT |
1414 | { |
1415 | return posix_cpu_clock_getres(PROCESS_CLOCK, tp); | |
1416 | } | |
a924b04d TG |
1417 | static int process_cpu_clock_get(const clockid_t which_clock, |
1418 | struct timespec *tp) | |
1da177e4 LT |
1419 | { |
1420 | return posix_cpu_clock_get(PROCESS_CLOCK, tp); | |
1421 | } | |
1422 | static int process_cpu_timer_create(struct k_itimer *timer) | |
1423 | { | |
1424 | timer->it_clock = PROCESS_CLOCK; | |
1425 | return posix_cpu_timer_create(timer); | |
1426 | } | |
a924b04d | 1427 | static int process_cpu_nsleep(const clockid_t which_clock, int flags, |
97735f25 TG |
1428 | struct timespec *rqtp, |
1429 | struct timespec __user *rmtp) | |
1da177e4 | 1430 | { |
97735f25 | 1431 | return posix_cpu_nsleep(PROCESS_CLOCK, flags, rqtp, rmtp); |
1da177e4 | 1432 | } |
1711ef38 TA |
1433 | static long process_cpu_nsleep_restart(struct restart_block *restart_block) |
1434 | { | |
1435 | return -EINVAL; | |
1436 | } | |
a924b04d TG |
1437 | static int thread_cpu_clock_getres(const clockid_t which_clock, |
1438 | struct timespec *tp) | |
1da177e4 LT |
1439 | { |
1440 | return posix_cpu_clock_getres(THREAD_CLOCK, tp); | |
1441 | } | |
a924b04d TG |
1442 | static int thread_cpu_clock_get(const clockid_t which_clock, |
1443 | struct timespec *tp) | |
1da177e4 LT |
1444 | { |
1445 | return posix_cpu_clock_get(THREAD_CLOCK, tp); | |
1446 | } | |
1447 | static int thread_cpu_timer_create(struct k_itimer *timer) | |
1448 | { | |
1449 | timer->it_clock = THREAD_CLOCK; | |
1450 | return posix_cpu_timer_create(timer); | |
1451 | } | |
1da177e4 | 1452 | |
1976945e TG |
1453 | struct k_clock clock_posix_cpu = { |
1454 | .clock_getres = posix_cpu_clock_getres, | |
1455 | .clock_set = posix_cpu_clock_set, | |
1456 | .clock_get = posix_cpu_clock_get, | |
1457 | .timer_create = posix_cpu_timer_create, | |
1458 | .nsleep = posix_cpu_nsleep, | |
1459 | .nsleep_restart = posix_cpu_nsleep_restart, | |
1460 | .timer_set = posix_cpu_timer_set, | |
1461 | .timer_del = posix_cpu_timer_del, | |
1462 | .timer_get = posix_cpu_timer_get, | |
1463 | }; | |
1464 | ||
1da177e4 LT |
1465 | static __init int init_posix_cpu_timers(void) |
1466 | { | |
1467 | struct k_clock process = { | |
2fd1f040 TG |
1468 | .clock_getres = process_cpu_clock_getres, |
1469 | .clock_get = process_cpu_clock_get, | |
2fd1f040 TG |
1470 | .timer_create = process_cpu_timer_create, |
1471 | .nsleep = process_cpu_nsleep, | |
1472 | .nsleep_restart = process_cpu_nsleep_restart, | |
1da177e4 LT |
1473 | }; |
1474 | struct k_clock thread = { | |
2fd1f040 TG |
1475 | .clock_getres = thread_cpu_clock_getres, |
1476 | .clock_get = thread_cpu_clock_get, | |
2fd1f040 | 1477 | .timer_create = thread_cpu_timer_create, |
1da177e4 | 1478 | }; |
8356b5f9 | 1479 | struct timespec ts; |
1da177e4 | 1480 | |
52708737 TG |
1481 | posix_timers_register_clock(CLOCK_PROCESS_CPUTIME_ID, &process); |
1482 | posix_timers_register_clock(CLOCK_THREAD_CPUTIME_ID, &thread); | |
1da177e4 | 1483 | |
a42548a1 | 1484 | cputime_to_timespec(cputime_one_jiffy, &ts); |
8356b5f9 SG |
1485 | onecputick = ts.tv_nsec; |
1486 | WARN_ON(ts.tv_sec != 0); | |
1487 | ||
1da177e4 LT |
1488 | return 0; |
1489 | } | |
1490 | __initcall(init_posix_cpu_timers); |