Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Uwe Zeisberger | f30c226 | 2006-10-03 23:01:26 +0200 | [diff] [blame] | 2 | * linux/kernel/posix-timers.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * |
| 5 | * 2002-10-15 Posix Clocks & timers |
| 6 | * by George Anzinger george@mvista.com |
| 7 | * |
| 8 | * Copyright (C) 2002 2003 by MontaVista Software. |
| 9 | * |
| 10 | * 2004-06-01 Fix CLOCK_REALTIME clock/timer TIMER_ABSTIME bug. |
| 11 | * Copyright (C) 2004 Boris Hu |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2 of the License, or (at |
| 16 | * your option) any later version. |
| 17 | * |
| 18 | * This program is distributed in the hope that it will be useful, but |
| 19 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 21 | * General Public License for more details. |
| 22 | |
| 23 | * You should have received a copy of the GNU General Public License |
| 24 | * along with this program; if not, write to the Free Software |
| 25 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 26 | * |
| 27 | * MontaVista Software | 1237 East Arques Avenue | Sunnyvale | CA 94085 | USA |
| 28 | */ |
| 29 | |
| 30 | /* These are all the functions necessary to implement |
| 31 | * POSIX clocks & timers |
| 32 | */ |
| 33 | #include <linux/mm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #include <linux/interrupt.h> |
| 35 | #include <linux/slab.h> |
| 36 | #include <linux/time.h> |
Arjan van de Ven | 97d1f15 | 2006-03-23 03:00:24 -0800 | [diff] [blame] | 37 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
| 39 | #include <asm/uaccess.h> |
| 40 | #include <asm/semaphore.h> |
| 41 | #include <linux/list.h> |
| 42 | #include <linux/init.h> |
| 43 | #include <linux/compiler.h> |
| 44 | #include <linux/idr.h> |
| 45 | #include <linux/posix-timers.h> |
| 46 | #include <linux/syscalls.h> |
| 47 | #include <linux/wait.h> |
| 48 | #include <linux/workqueue.h> |
| 49 | #include <linux/module.h> |
| 50 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | /* |
| 52 | * Management arrays for POSIX timers. Timers are kept in slab memory |
| 53 | * Timer ids are allocated by an external routine that keeps track of the |
| 54 | * id and the timer. The external interface is: |
| 55 | * |
| 56 | * void *idr_find(struct idr *idp, int id); to find timer_id <id> |
| 57 | * int idr_get_new(struct idr *idp, void *ptr); to get a new id and |
| 58 | * related it to <ptr> |
| 59 | * void idr_remove(struct idr *idp, int id); to release <id> |
| 60 | * void idr_init(struct idr *idp); to initialize <idp> |
| 61 | * which we supply. |
| 62 | * The idr_get_new *may* call slab for more memory so it must not be |
| 63 | * called under a spin lock. Likewise idr_remore may release memory |
| 64 | * (but it may be ok to do this under a lock...). |
| 65 | * idr_find is just a memory look up and is quite fast. A -1 return |
| 66 | * indicates that the requested id does not exist. |
| 67 | */ |
| 68 | |
| 69 | /* |
| 70 | * Lets keep our timers in a slab cache :-) |
| 71 | */ |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 72 | static struct kmem_cache *posix_timers_cache; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | static struct idr posix_timers_id; |
| 74 | static DEFINE_SPINLOCK(idr_lock); |
| 75 | |
| 76 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | * we assume that the new SIGEV_THREAD_ID shares no bits with the other |
| 78 | * SIGEV values. Here we put out an error if this assumption fails. |
| 79 | */ |
| 80 | #if SIGEV_THREAD_ID != (SIGEV_THREAD_ID & \ |
| 81 | ~(SIGEV_SIGNAL | SIGEV_NONE | SIGEV_THREAD)) |
| 82 | #error "SIGEV_THREAD_ID must not share bit with other SIGEV values!" |
| 83 | #endif |
| 84 | |
| 85 | |
| 86 | /* |
| 87 | * The timer ID is turned into a timer address by idr_find(). |
| 88 | * Verifying a valid ID consists of: |
| 89 | * |
| 90 | * a) checking that idr_find() returns other than -1. |
| 91 | * b) checking that the timer id matches the one in the timer itself. |
| 92 | * c) that the timer owner is in the callers thread group. |
| 93 | */ |
| 94 | |
| 95 | /* |
| 96 | * CLOCKs: The POSIX standard calls for a couple of clocks and allows us |
| 97 | * to implement others. This structure defines the various |
| 98 | * clocks and allows the possibility of adding others. We |
| 99 | * provide an interface to add clocks to the table and expect |
| 100 | * the "arch" code to add at least one clock that is high |
| 101 | * resolution. Here we define the standard CLOCK_REALTIME as a |
| 102 | * 1/HZ resolution clock. |
| 103 | * |
| 104 | * RESOLUTION: Clock resolution is used to round up timer and interval |
| 105 | * times, NOT to report clock times, which are reported with as |
| 106 | * much resolution as the system can muster. In some cases this |
| 107 | * resolution may depend on the underlying clock hardware and |
| 108 | * may not be quantifiable until run time, and only then is the |
| 109 | * necessary code is written. The standard says we should say |
| 110 | * something about this issue in the documentation... |
| 111 | * |
| 112 | * FUNCTIONS: The CLOCKs structure defines possible functions to handle |
| 113 | * various clock functions. For clocks that use the standard |
| 114 | * system timer code these entries should be NULL. This will |
| 115 | * allow dispatch without the overhead of indirect function |
| 116 | * calls. CLOCKS that depend on other sources (e.g. WWV or GPS) |
| 117 | * must supply functions here, even if the function just returns |
| 118 | * ENOSYS. The standard POSIX timer management code assumes the |
| 119 | * following: 1.) The k_itimer struct (sched.h) is used for the |
| 120 | * timer. 2.) The list, it_lock, it_clock, it_id and it_process |
| 121 | * fields are not modified by timer code. |
| 122 | * |
| 123 | * At this time all functions EXCEPT clock_nanosleep can be |
| 124 | * redirected by the CLOCKS structure. Clock_nanosleep is in |
| 125 | * there, but the code ignores it. |
| 126 | * |
| 127 | * Permissions: It is assumed that the clock_settime() function defined |
| 128 | * for each clock will take care of permission checks. Some |
| 129 | * clocks may be set able by any user (i.e. local process |
| 130 | * clocks) others not. Currently the only set able clock we |
| 131 | * have is CLOCK_REALTIME and its high res counter part, both of |
| 132 | * which we beg off on and pass to do_sys_settimeofday(). |
| 133 | */ |
| 134 | |
| 135 | static struct k_clock posix_clocks[MAX_CLOCKS]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 137 | /* |
| 138 | * These ones are defined below. |
| 139 | */ |
| 140 | static int common_nsleep(const clockid_t, int flags, struct timespec *t, |
| 141 | struct timespec __user *rmtp); |
| 142 | static void common_timer_get(struct k_itimer *, struct itimerspec *); |
| 143 | static int common_timer_set(struct k_itimer *, int, |
| 144 | struct itimerspec *, struct itimerspec *); |
| 145 | static int common_timer_del(struct k_itimer *timer); |
| 146 | |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 147 | static enum hrtimer_restart posix_timer_fn(struct hrtimer *data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | |
| 149 | static struct k_itimer *lock_timer(timer_t timer_id, unsigned long *flags); |
| 150 | |
| 151 | static inline void unlock_timer(struct k_itimer *timr, unsigned long flags) |
| 152 | { |
| 153 | spin_unlock_irqrestore(&timr->it_lock, flags); |
| 154 | } |
| 155 | |
| 156 | /* |
| 157 | * Call the k_clock hook function if non-null, or the default function. |
| 158 | */ |
| 159 | #define CLOCK_DISPATCH(clock, call, arglist) \ |
| 160 | ((clock) < 0 ? posix_cpu_##call arglist : \ |
| 161 | (posix_clocks[clock].call != NULL \ |
| 162 | ? (*posix_clocks[clock].call) arglist : common_##call arglist)) |
| 163 | |
| 164 | /* |
| 165 | * Default clock hook functions when the struct k_clock passed |
| 166 | * to register_posix_clock leaves a function pointer null. |
| 167 | * |
| 168 | * The function common_CALL is the default implementation for |
| 169 | * the function pointer CALL in struct k_clock. |
| 170 | */ |
| 171 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 172 | static inline int common_clock_getres(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | struct timespec *tp) |
| 174 | { |
| 175 | tp->tv_sec = 0; |
| 176 | tp->tv_nsec = posix_clocks[which_clock].res; |
| 177 | return 0; |
| 178 | } |
| 179 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 180 | /* |
| 181 | * Get real time for posix timers |
| 182 | */ |
| 183 | static int common_clock_get(clockid_t which_clock, struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | { |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 185 | ktime_get_real_ts(tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | return 0; |
| 187 | } |
| 188 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 189 | static inline int common_clock_set(const clockid_t which_clock, |
| 190 | struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | { |
| 192 | return do_sys_settimeofday(tp, NULL); |
| 193 | } |
| 194 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 195 | static int common_timer_create(struct k_itimer *new_timer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 196 | { |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 197 | hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | /* |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 202 | * Return nonzero if we know a priori this clockid_t value is bogus. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | */ |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 204 | static inline int invalid_clockid(const clockid_t which_clock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | { |
| 206 | if (which_clock < 0) /* CPU clock, posix_cpu_* will check it */ |
| 207 | return 0; |
| 208 | if ((unsigned) which_clock >= MAX_CLOCKS) |
| 209 | return 1; |
| 210 | if (posix_clocks[which_clock].clock_getres != NULL) |
| 211 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | if (posix_clocks[which_clock].res != 0) |
| 213 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | return 1; |
| 215 | } |
| 216 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 217 | /* |
| 218 | * Get monotonic time for posix timers |
| 219 | */ |
| 220 | static int posix_ktime_get_ts(clockid_t which_clock, struct timespec *tp) |
| 221 | { |
| 222 | ktime_get_ts(tp); |
| 223 | return 0; |
| 224 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
| 226 | /* |
| 227 | * Initialize everything, well, just everything in Posix clocks/timers ;) |
| 228 | */ |
| 229 | static __init int init_posix_timers(void) |
| 230 | { |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 231 | struct k_clock clock_realtime = { |
| 232 | .clock_getres = hrtimer_get_res, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | }; |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 234 | struct k_clock clock_monotonic = { |
| 235 | .clock_getres = hrtimer_get_res, |
| 236 | .clock_get = posix_ktime_get_ts, |
| 237 | .clock_set = do_posix_clock_nosettime, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | }; |
| 239 | |
| 240 | register_posix_clock(CLOCK_REALTIME, &clock_realtime); |
| 241 | register_posix_clock(CLOCK_MONOTONIC, &clock_monotonic); |
| 242 | |
| 243 | posix_timers_cache = kmem_cache_create("posix_timers_cache", |
Alexey Dobriyan | 040b5c6 | 2007-10-16 23:26:10 -0700 | [diff] [blame] | 244 | sizeof (struct k_itimer), 0, SLAB_PANIC, |
| 245 | NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | idr_init(&posix_timers_id); |
| 247 | return 0; |
| 248 | } |
| 249 | |
| 250 | __initcall(init_posix_timers); |
| 251 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | static void schedule_next_timer(struct k_itimer *timr) |
| 253 | { |
Roman Zippel | 44f2147 | 2006-03-26 01:38:06 -0800 | [diff] [blame] | 254 | struct hrtimer *timer = &timr->it.real.timer; |
| 255 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 256 | if (timr->it.real.interval.tv64 == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | return; |
| 258 | |
Davide Libenzi | 4d672e7 | 2008-02-04 22:27:26 -0800 | [diff] [blame] | 259 | timr->it_overrun += (unsigned int) hrtimer_forward(timer, |
| 260 | timer->base->get_time(), |
| 261 | timr->it.real.interval); |
Roman Zippel | 44f2147 | 2006-03-26 01:38:06 -0800 | [diff] [blame] | 262 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | timr->it_overrun_last = timr->it_overrun; |
| 264 | timr->it_overrun = -1; |
| 265 | ++timr->it_requeue_pending; |
Roman Zippel | 44f2147 | 2006-03-26 01:38:06 -0800 | [diff] [blame] | 266 | hrtimer_restart(timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | } |
| 268 | |
| 269 | /* |
| 270 | * This function is exported for use by the signal deliver code. It is |
| 271 | * called just prior to the info block being released and passes that |
| 272 | * block to us. It's function is to update the overrun entry AND to |
| 273 | * restart the timer. It should only be called if the timer is to be |
| 274 | * restarted (i.e. we have flagged this in the sys_private entry of the |
| 275 | * info block). |
| 276 | * |
| 277 | * To protect aginst the timer going away while the interrupt is queued, |
| 278 | * we require that the it_requeue_pending flag be set. |
| 279 | */ |
| 280 | void do_schedule_next_timer(struct siginfo *info) |
| 281 | { |
| 282 | struct k_itimer *timr; |
| 283 | unsigned long flags; |
| 284 | |
| 285 | timr = lock_timer(info->si_tid, &flags); |
| 286 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 287 | if (timr && timr->it_requeue_pending == info->si_sys_private) { |
| 288 | if (timr->it_clock < 0) |
| 289 | posix_cpu_timer_schedule(timr); |
| 290 | else |
| 291 | schedule_next_timer(timr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 293 | info->si_overrun = timr->it_overrun_last; |
| 294 | } |
| 295 | |
Thomas Gleixner | b6557fb | 2006-02-01 03:05:09 -0800 | [diff] [blame] | 296 | if (timr) |
| 297 | unlock_timer(timr, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | } |
| 299 | |
| 300 | int posix_timer_event(struct k_itimer *timr,int si_private) |
| 301 | { |
| 302 | memset(&timr->sigq->info, 0, sizeof(siginfo_t)); |
| 303 | timr->sigq->info.si_sys_private = si_private; |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 304 | /* Send signal to the process that owns this timer.*/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | |
| 306 | timr->sigq->info.si_signo = timr->it_sigev_signo; |
| 307 | timr->sigq->info.si_errno = 0; |
| 308 | timr->sigq->info.si_code = SI_TIMER; |
| 309 | timr->sigq->info.si_tid = timr->it_id; |
| 310 | timr->sigq->info.si_value = timr->it_sigev_value; |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 311 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | if (timr->it_sigev_notify & SIGEV_THREAD_ID) { |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 313 | struct task_struct *leader; |
| 314 | int ret = send_sigqueue(timr->it_sigev_signo, timr->sigq, |
| 315 | timr->it_process); |
| 316 | |
| 317 | if (likely(ret >= 0)) |
| 318 | return ret; |
| 319 | |
| 320 | timr->it_sigev_notify = SIGEV_SIGNAL; |
| 321 | leader = timr->it_process->group_leader; |
| 322 | put_task_struct(timr->it_process); |
| 323 | timr->it_process = leader; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 324 | } |
Oleg Nesterov | e752dd6 | 2005-09-06 15:17:42 -0700 | [diff] [blame] | 325 | |
| 326 | return send_group_sigqueue(timr->it_sigev_signo, timr->sigq, |
| 327 | timr->it_process); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | } |
| 329 | EXPORT_SYMBOL_GPL(posix_timer_event); |
| 330 | |
| 331 | /* |
| 332 | * This function gets called when a POSIX.1b interval timer expires. It |
| 333 | * is used as a callback from the kernel internal timer. The |
| 334 | * run_timer_list code ALWAYS calls with interrupts on. |
| 335 | |
| 336 | * This code is for CLOCK_REALTIME* and CLOCK_MONOTONIC* timers. |
| 337 | */ |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 338 | static enum hrtimer_restart posix_timer_fn(struct hrtimer *timer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | { |
Roman Zippel | 05cfb61 | 2006-03-26 01:38:12 -0800 | [diff] [blame] | 340 | struct k_itimer *timr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | unsigned long flags; |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 342 | int si_private = 0; |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 343 | enum hrtimer_restart ret = HRTIMER_NORESTART; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | |
Roman Zippel | 05cfb61 | 2006-03-26 01:38:12 -0800 | [diff] [blame] | 345 | timr = container_of(timer, struct k_itimer, it.real.timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | spin_lock_irqsave(&timr->it_lock, flags); |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 347 | |
| 348 | if (timr->it.real.interval.tv64 != 0) |
| 349 | si_private = ++timr->it_requeue_pending; |
| 350 | |
| 351 | if (posix_timer_event(timr, si_private)) { |
| 352 | /* |
| 353 | * signal was not sent because of sig_ignor |
| 354 | * we will not get a call back to restart it AND |
| 355 | * it should be restarted. |
| 356 | */ |
| 357 | if (timr->it.real.interval.tv64 != 0) { |
Thomas Gleixner | 58229a1 | 2007-06-21 20:45:15 +0000 | [diff] [blame] | 358 | ktime_t now = hrtimer_cb_get_time(timer); |
| 359 | |
| 360 | /* |
| 361 | * FIXME: What we really want, is to stop this |
| 362 | * timer completely and restart it in case the |
| 363 | * SIG_IGN is removed. This is a non trivial |
| 364 | * change which involves sighand locking |
| 365 | * (sigh !), which we don't want to do late in |
| 366 | * the release cycle. |
| 367 | * |
| 368 | * For now we just let timers with an interval |
| 369 | * less than a jiffie expire every jiffie to |
| 370 | * avoid softirq starvation in case of SIG_IGN |
| 371 | * and a very small interval, which would put |
| 372 | * the timer right back on the softirq pending |
| 373 | * list. By moving now ahead of time we trick |
| 374 | * hrtimer_forward() to expire the timer |
| 375 | * later, while we still maintain the overrun |
| 376 | * accuracy, but have some inconsistency in |
| 377 | * the timer_gettime() case. This is at least |
| 378 | * better than a starved softirq. A more |
| 379 | * complex fix which solves also another related |
| 380 | * inconsistency is already in the pipeline. |
| 381 | */ |
| 382 | #ifdef CONFIG_HIGH_RES_TIMERS |
| 383 | { |
| 384 | ktime_t kj = ktime_set(0, NSEC_PER_SEC / HZ); |
| 385 | |
| 386 | if (timr->it.real.interval.tv64 < kj.tv64) |
| 387 | now = ktime_add(now, kj); |
| 388 | } |
| 389 | #endif |
Davide Libenzi | 4d672e7 | 2008-02-04 22:27:26 -0800 | [diff] [blame] | 390 | timr->it_overrun += (unsigned int) |
Thomas Gleixner | 58229a1 | 2007-06-21 20:45:15 +0000 | [diff] [blame] | 391 | hrtimer_forward(timer, now, |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 392 | timr->it.real.interval); |
| 393 | ret = HRTIMER_RESTART; |
Roman Zippel | a0a0c28 | 2006-03-16 23:04:01 -0800 | [diff] [blame] | 394 | ++timr->it_requeue_pending; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 398 | unlock_timer(timr, flags); |
| 399 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | } |
| 401 | |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 402 | static struct task_struct * good_sigevent(sigevent_t * event) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | { |
| 404 | struct task_struct *rtn = current->group_leader; |
| 405 | |
| 406 | if ((event->sigev_notify & SIGEV_THREAD_ID ) && |
Pavel Emelyanov | 8dc86af | 2008-02-08 04:21:52 -0800 | [diff] [blame] | 407 | (!(rtn = find_task_by_vpid(event->sigev_notify_thread_id)) || |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 408 | !same_thread_group(rtn, current) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | (event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_SIGNAL)) |
| 410 | return NULL; |
| 411 | |
| 412 | if (((event->sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) && |
| 413 | ((event->sigev_signo <= 0) || (event->sigev_signo > SIGRTMAX))) |
| 414 | return NULL; |
| 415 | |
| 416 | return rtn; |
| 417 | } |
| 418 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 419 | void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | { |
| 421 | if ((unsigned) clock_id >= MAX_CLOCKS) { |
| 422 | printk("POSIX clock register failed for clock_id %d\n", |
| 423 | clock_id); |
| 424 | return; |
| 425 | } |
| 426 | |
| 427 | posix_clocks[clock_id] = *new_clock; |
| 428 | } |
| 429 | EXPORT_SYMBOL_GPL(register_posix_clock); |
| 430 | |
| 431 | static struct k_itimer * alloc_posix_timer(void) |
| 432 | { |
| 433 | struct k_itimer *tmr; |
Robert P. J. Day | c376222 | 2007-02-10 01:45:03 -0800 | [diff] [blame] | 434 | tmr = kmem_cache_zalloc(posix_timers_cache, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | if (!tmr) |
| 436 | return tmr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 437 | if (unlikely(!(tmr->sigq = sigqueue_alloc()))) { |
| 438 | kmem_cache_free(posix_timers_cache, tmr); |
| 439 | tmr = NULL; |
| 440 | } |
| 441 | return tmr; |
| 442 | } |
| 443 | |
| 444 | #define IT_ID_SET 1 |
| 445 | #define IT_ID_NOT_SET 0 |
| 446 | static void release_posix_timer(struct k_itimer *tmr, int it_id_set) |
| 447 | { |
| 448 | if (it_id_set) { |
| 449 | unsigned long flags; |
| 450 | spin_lock_irqsave(&idr_lock, flags); |
| 451 | idr_remove(&posix_timers_id, tmr->it_id); |
| 452 | spin_unlock_irqrestore(&idr_lock, flags); |
| 453 | } |
| 454 | sigqueue_free(tmr->sigq); |
| 455 | if (unlikely(tmr->it_process) && |
| 456 | tmr->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| 457 | put_task_struct(tmr->it_process); |
| 458 | kmem_cache_free(posix_timers_cache, tmr); |
| 459 | } |
| 460 | |
| 461 | /* Create a POSIX.1b interval timer. */ |
| 462 | |
| 463 | asmlinkage long |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 464 | sys_timer_create(const clockid_t which_clock, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | struct sigevent __user *timer_event_spec, |
| 466 | timer_t __user * created_timer_id) |
| 467 | { |
| 468 | int error = 0; |
| 469 | struct k_itimer *new_timer = NULL; |
| 470 | int new_timer_id; |
| 471 | struct task_struct *process = NULL; |
| 472 | unsigned long flags; |
| 473 | sigevent_t event; |
| 474 | int it_id_set = IT_ID_NOT_SET; |
| 475 | |
| 476 | if (invalid_clockid(which_clock)) |
| 477 | return -EINVAL; |
| 478 | |
| 479 | new_timer = alloc_posix_timer(); |
| 480 | if (unlikely(!new_timer)) |
| 481 | return -EAGAIN; |
| 482 | |
| 483 | spin_lock_init(&new_timer->it_lock); |
| 484 | retry: |
| 485 | if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) { |
| 486 | error = -EAGAIN; |
| 487 | goto out; |
| 488 | } |
| 489 | spin_lock_irq(&idr_lock); |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 490 | error = idr_get_new(&posix_timers_id, (void *) new_timer, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | &new_timer_id); |
| 492 | spin_unlock_irq(&idr_lock); |
| 493 | if (error == -EAGAIN) |
| 494 | goto retry; |
| 495 | else if (error) { |
| 496 | /* |
Joe Perches | 0b0a3e7 | 2008-02-03 17:48:04 +0200 | [diff] [blame] | 497 | * Weird looking, but we return EAGAIN if the IDR is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | * full (proper POSIX return value for this) |
| 499 | */ |
| 500 | error = -EAGAIN; |
| 501 | goto out; |
| 502 | } |
| 503 | |
| 504 | it_id_set = IT_ID_SET; |
| 505 | new_timer->it_id = (timer_t) new_timer_id; |
| 506 | new_timer->it_clock = which_clock; |
| 507 | new_timer->it_overrun = -1; |
| 508 | error = CLOCK_DISPATCH(which_clock, timer_create, (new_timer)); |
| 509 | if (error) |
| 510 | goto out; |
| 511 | |
| 512 | /* |
| 513 | * return the timer_id now. The next step is hard to |
| 514 | * back out if there is an error. |
| 515 | */ |
| 516 | if (copy_to_user(created_timer_id, |
| 517 | &new_timer_id, sizeof (new_timer_id))) { |
| 518 | error = -EFAULT; |
| 519 | goto out; |
| 520 | } |
| 521 | if (timer_event_spec) { |
| 522 | if (copy_from_user(&event, timer_event_spec, sizeof (event))) { |
| 523 | error = -EFAULT; |
| 524 | goto out; |
| 525 | } |
| 526 | new_timer->it_sigev_notify = event.sigev_notify; |
| 527 | new_timer->it_sigev_signo = event.sigev_signo; |
| 528 | new_timer->it_sigev_value = event.sigev_value; |
| 529 | |
| 530 | read_lock(&tasklist_lock); |
| 531 | if ((process = good_sigevent(&event))) { |
| 532 | /* |
| 533 | * We may be setting up this process for another |
| 534 | * thread. It may be exiting. To catch this |
| 535 | * case the we check the PF_EXITING flag. If |
| 536 | * the flag is not set, the siglock will catch |
| 537 | * him before it is too late (in exit_itimers). |
| 538 | * |
| 539 | * The exec case is a bit more invloved but easy |
| 540 | * to code. If the process is in our thread |
| 541 | * group (and it must be or we would not allow |
| 542 | * it here) and is doing an exec, it will cause |
| 543 | * us to be killed. In this case it will wait |
| 544 | * for us to die which means we can finish this |
| 545 | * linkage with our last gasp. I.e. no code :) |
| 546 | */ |
| 547 | spin_lock_irqsave(&process->sighand->siglock, flags); |
| 548 | if (!(process->flags & PF_EXITING)) { |
| 549 | new_timer->it_process = process; |
| 550 | list_add(&new_timer->list, |
| 551 | &process->signal->posix_timers); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | if (new_timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| 553 | get_task_struct(process); |
Oleg Nesterov | d02479b | 2007-08-22 14:01:37 -0700 | [diff] [blame] | 554 | spin_unlock_irqrestore(&process->sighand->siglock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | } else { |
| 556 | spin_unlock_irqrestore(&process->sighand->siglock, flags); |
| 557 | process = NULL; |
| 558 | } |
| 559 | } |
| 560 | read_unlock(&tasklist_lock); |
| 561 | if (!process) { |
| 562 | error = -EINVAL; |
| 563 | goto out; |
| 564 | } |
| 565 | } else { |
| 566 | new_timer->it_sigev_notify = SIGEV_SIGNAL; |
| 567 | new_timer->it_sigev_signo = SIGALRM; |
| 568 | new_timer->it_sigev_value.sival_int = new_timer->it_id; |
| 569 | process = current->group_leader; |
| 570 | spin_lock_irqsave(&process->sighand->siglock, flags); |
| 571 | new_timer->it_process = process; |
| 572 | list_add(&new_timer->list, &process->signal->posix_timers); |
| 573 | spin_unlock_irqrestore(&process->sighand->siglock, flags); |
| 574 | } |
| 575 | |
| 576 | /* |
| 577 | * In the case of the timer belonging to another task, after |
| 578 | * the task is unlocked, the timer is owned by the other task |
| 579 | * and may cease to exist at any time. Don't use or modify |
| 580 | * new_timer after the unlock call. |
| 581 | */ |
| 582 | |
| 583 | out: |
| 584 | if (error) |
| 585 | release_posix_timer(new_timer, it_id_set); |
| 586 | |
| 587 | return error; |
| 588 | } |
| 589 | |
| 590 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | * Locking issues: We need to protect the result of the id look up until |
| 592 | * we get the timer locked down so it is not deleted under us. The |
| 593 | * removal is done under the idr spinlock so we use that here to bridge |
| 594 | * the find to the timer lock. To avoid a dead lock, the timer id MUST |
| 595 | * be release with out holding the timer lock. |
| 596 | */ |
| 597 | static struct k_itimer * lock_timer(timer_t timer_id, unsigned long *flags) |
| 598 | { |
| 599 | struct k_itimer *timr; |
| 600 | /* |
| 601 | * Watch out here. We do a irqsave on the idr_lock and pass the |
| 602 | * flags part over to the timer lock. Must not let interrupts in |
| 603 | * while we are moving the lock. |
| 604 | */ |
| 605 | |
| 606 | spin_lock_irqsave(&idr_lock, *flags); |
| 607 | timr = (struct k_itimer *) idr_find(&posix_timers_id, (int) timer_id); |
| 608 | if (timr) { |
| 609 | spin_lock(&timr->it_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 610 | |
| 611 | if ((timr->it_id != timer_id) || !(timr->it_process) || |
Pavel Emelyanov | bac0abd | 2007-10-18 23:40:18 -0700 | [diff] [blame] | 612 | !same_thread_group(timr->it_process, current)) { |
Thomas Gleixner | 179394a | 2007-08-22 14:01:37 -0700 | [diff] [blame] | 613 | spin_unlock(&timr->it_lock); |
| 614 | spin_unlock_irqrestore(&idr_lock, *flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | timr = NULL; |
Thomas Gleixner | 179394a | 2007-08-22 14:01:37 -0700 | [diff] [blame] | 616 | } else |
| 617 | spin_unlock(&idr_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | } else |
| 619 | spin_unlock_irqrestore(&idr_lock, *flags); |
| 620 | |
| 621 | return timr; |
| 622 | } |
| 623 | |
| 624 | /* |
| 625 | * Get the time remaining on a POSIX.1b interval timer. This function |
| 626 | * is ALWAYS called with spin_lock_irq on the timer, thus it must not |
| 627 | * mess with irq. |
| 628 | * |
| 629 | * We have a couple of messes to clean up here. First there is the case |
| 630 | * of a timer that has a requeue pending. These timers should appear to |
| 631 | * be in the timer list with an expiry as if we were to requeue them |
| 632 | * now. |
| 633 | * |
| 634 | * The second issue is the SIGEV_NONE timer which may be active but is |
| 635 | * not really ever put in the timer list (to save system resources). |
| 636 | * This timer may be expired, and if so, we will do it here. Otherwise |
| 637 | * it is the same as a requeue pending timer WRT to what we should |
| 638 | * report. |
| 639 | */ |
| 640 | static void |
| 641 | common_timer_get(struct k_itimer *timr, struct itimerspec *cur_setting) |
| 642 | { |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 643 | ktime_t now, remaining, iv; |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 644 | struct hrtimer *timer = &timr->it.real.timer; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 646 | memset(cur_setting, 0, sizeof(struct itimerspec)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 648 | iv = timr->it.real.interval; |
| 649 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 650 | /* interval timer ? */ |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 651 | if (iv.tv64) |
| 652 | cur_setting->it_interval = ktime_to_timespec(iv); |
| 653 | else if (!hrtimer_active(timer) && |
| 654 | (timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 655 | return; |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 656 | |
| 657 | now = timer->base->get_time(); |
| 658 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 659 | /* |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 660 | * When a requeue is pending or this is a SIGEV_NONE |
| 661 | * timer move the expiry time forward by intervals, so |
| 662 | * expiry is > now. |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 663 | */ |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 664 | if (iv.tv64 && (timr->it_requeue_pending & REQUEUE_PENDING || |
| 665 | (timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) |
Davide Libenzi | 4d672e7 | 2008-02-04 22:27:26 -0800 | [diff] [blame] | 666 | timr->it_overrun += (unsigned int) hrtimer_forward(timer, now, iv); |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 667 | |
| 668 | remaining = ktime_sub(timer->expires, now); |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 669 | /* Return 0 only, when the timer is expired and not pending */ |
Roman Zippel | 3b98a53 | 2006-03-26 01:38:07 -0800 | [diff] [blame] | 670 | if (remaining.tv64 <= 0) { |
| 671 | /* |
| 672 | * A single shot SIGEV_NONE timer must return 0, when |
| 673 | * it is expired ! |
| 674 | */ |
| 675 | if ((timr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) |
| 676 | cur_setting->it_value.tv_nsec = 1; |
| 677 | } else |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 678 | cur_setting->it_value = ktime_to_timespec(remaining); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 679 | } |
| 680 | |
| 681 | /* Get the time remaining on a POSIX.1b interval timer. */ |
| 682 | asmlinkage long |
| 683 | sys_timer_gettime(timer_t timer_id, struct itimerspec __user *setting) |
| 684 | { |
| 685 | struct k_itimer *timr; |
| 686 | struct itimerspec cur_setting; |
| 687 | unsigned long flags; |
| 688 | |
| 689 | timr = lock_timer(timer_id, &flags); |
| 690 | if (!timr) |
| 691 | return -EINVAL; |
| 692 | |
| 693 | CLOCK_DISPATCH(timr->it_clock, timer_get, (timr, &cur_setting)); |
| 694 | |
| 695 | unlock_timer(timr, flags); |
| 696 | |
| 697 | if (copy_to_user(setting, &cur_setting, sizeof (cur_setting))) |
| 698 | return -EFAULT; |
| 699 | |
| 700 | return 0; |
| 701 | } |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 702 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | /* |
| 704 | * Get the number of overruns of a POSIX.1b interval timer. This is to |
| 705 | * be the overrun of the timer last delivered. At the same time we are |
| 706 | * accumulating overruns on the next timer. The overrun is frozen when |
| 707 | * the signal is delivered, either at the notify time (if the info block |
| 708 | * is not queued) or at the actual delivery time (as we are informed by |
| 709 | * the call back to do_schedule_next_timer(). So all we need to do is |
| 710 | * to pick up the frozen overrun. |
| 711 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 712 | asmlinkage long |
| 713 | sys_timer_getoverrun(timer_t timer_id) |
| 714 | { |
| 715 | struct k_itimer *timr; |
| 716 | int overrun; |
Al Viro | 5ba2533 | 2007-10-14 19:35:50 +0100 | [diff] [blame] | 717 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 718 | |
| 719 | timr = lock_timer(timer_id, &flags); |
| 720 | if (!timr) |
| 721 | return -EINVAL; |
| 722 | |
| 723 | overrun = timr->it_overrun_last; |
| 724 | unlock_timer(timr, flags); |
| 725 | |
| 726 | return overrun; |
| 727 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | |
| 729 | /* Set a POSIX.1b interval timer. */ |
| 730 | /* timr->it_lock is taken. */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 731 | static int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | common_timer_set(struct k_itimer *timr, int flags, |
| 733 | struct itimerspec *new_setting, struct itimerspec *old_setting) |
| 734 | { |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 735 | struct hrtimer *timer = &timr->it.real.timer; |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 736 | enum hrtimer_mode mode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 737 | |
| 738 | if (old_setting) |
| 739 | common_timer_get(timr, old_setting); |
| 740 | |
| 741 | /* disable the timer */ |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 742 | timr->it.real.interval.tv64 = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | /* |
| 744 | * careful here. If smp we could be in the "fire" routine which will |
| 745 | * be spinning as we hold the lock. But this is ONLY an SMP issue. |
| 746 | */ |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 747 | if (hrtimer_try_to_cancel(timer) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 748 | return TIMER_RETRY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | |
| 750 | timr->it_requeue_pending = (timr->it_requeue_pending + 2) & |
| 751 | ~REQUEUE_PENDING; |
| 752 | timr->it_overrun_last = 0; |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 753 | |
| 754 | /* switch off the timer when it_value is zero */ |
| 755 | if (!new_setting->it_value.tv_sec && !new_setting->it_value.tv_nsec) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 756 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | |
Thomas Gleixner | c9cb2e3 | 2007-02-16 01:27:49 -0800 | [diff] [blame] | 758 | mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 759 | hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 760 | timr->it.real.timer.function = posix_timer_fn; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 762 | timer->expires = timespec_to_ktime(new_setting->it_value); |
| 763 | |
| 764 | /* Convert interval */ |
| 765 | timr->it.real.interval = timespec_to_ktime(new_setting->it_interval); |
| 766 | |
| 767 | /* SIGEV_NONE timers are not queued ! See common_timer_get */ |
Thomas Gleixner | 952bbc8 | 2006-02-01 03:05:13 -0800 | [diff] [blame] | 768 | if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) { |
| 769 | /* Setup correct expiry time for relative timers */ |
Thomas Gleixner | 5a7780e | 2008-02-13 09:20:43 +0100 | [diff] [blame] | 770 | if (mode == HRTIMER_MODE_REL) { |
| 771 | timer->expires = |
| 772 | ktime_add_safe(timer->expires, |
| 773 | timer->base->get_time()); |
| 774 | } |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 775 | return 0; |
Thomas Gleixner | 952bbc8 | 2006-02-01 03:05:13 -0800 | [diff] [blame] | 776 | } |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 777 | |
George Anzinger | 7978672c | 2006-02-01 03:05:11 -0800 | [diff] [blame] | 778 | hrtimer_start(timer, timer->expires, mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | return 0; |
| 780 | } |
| 781 | |
| 782 | /* Set a POSIX.1b interval timer */ |
| 783 | asmlinkage long |
| 784 | sys_timer_settime(timer_t timer_id, int flags, |
| 785 | const struct itimerspec __user *new_setting, |
| 786 | struct itimerspec __user *old_setting) |
| 787 | { |
| 788 | struct k_itimer *timr; |
| 789 | struct itimerspec new_spec, old_spec; |
| 790 | int error = 0; |
Al Viro | 5ba2533 | 2007-10-14 19:35:50 +0100 | [diff] [blame] | 791 | unsigned long flag; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | struct itimerspec *rtn = old_setting ? &old_spec : NULL; |
| 793 | |
| 794 | if (!new_setting) |
| 795 | return -EINVAL; |
| 796 | |
| 797 | if (copy_from_user(&new_spec, new_setting, sizeof (new_spec))) |
| 798 | return -EFAULT; |
| 799 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 800 | if (!timespec_valid(&new_spec.it_interval) || |
| 801 | !timespec_valid(&new_spec.it_value)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | return -EINVAL; |
| 803 | retry: |
| 804 | timr = lock_timer(timer_id, &flag); |
| 805 | if (!timr) |
| 806 | return -EINVAL; |
| 807 | |
| 808 | error = CLOCK_DISPATCH(timr->it_clock, timer_set, |
| 809 | (timr, flags, &new_spec, rtn)); |
| 810 | |
| 811 | unlock_timer(timr, flag); |
| 812 | if (error == TIMER_RETRY) { |
| 813 | rtn = NULL; // We already got the old time... |
| 814 | goto retry; |
| 815 | } |
| 816 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 817 | if (old_setting && !error && |
| 818 | copy_to_user(old_setting, &old_spec, sizeof (old_spec))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | error = -EFAULT; |
| 820 | |
| 821 | return error; |
| 822 | } |
| 823 | |
| 824 | static inline int common_timer_del(struct k_itimer *timer) |
| 825 | { |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 826 | timer->it.real.interval.tv64 = 0; |
Oleg Nesterov | f972be3 | 2005-06-23 00:09:00 -0700 | [diff] [blame] | 827 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 828 | if (hrtimer_try_to_cancel(&timer->it.real.timer) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | return TIMER_RETRY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | return 0; |
| 831 | } |
| 832 | |
| 833 | static inline int timer_delete_hook(struct k_itimer *timer) |
| 834 | { |
| 835 | return CLOCK_DISPATCH(timer->it_clock, timer_del, (timer)); |
| 836 | } |
| 837 | |
| 838 | /* Delete a POSIX.1b interval timer. */ |
| 839 | asmlinkage long |
| 840 | sys_timer_delete(timer_t timer_id) |
| 841 | { |
| 842 | struct k_itimer *timer; |
Al Viro | 5ba2533 | 2007-10-14 19:35:50 +0100 | [diff] [blame] | 843 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 844 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | retry_delete: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 846 | timer = lock_timer(timer_id, &flags); |
| 847 | if (!timer) |
| 848 | return -EINVAL; |
| 849 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 850 | if (timer_delete_hook(timer) == TIMER_RETRY) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | unlock_timer(timer, flags); |
| 852 | goto retry_delete; |
| 853 | } |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 854 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 855 | spin_lock(¤t->sighand->siglock); |
| 856 | list_del(&timer->list); |
| 857 | spin_unlock(¤t->sighand->siglock); |
| 858 | /* |
| 859 | * This keeps any tasks waiting on the spin lock from thinking |
| 860 | * they got something (see the lock code above). |
| 861 | */ |
| 862 | if (timer->it_process) { |
| 863 | if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| 864 | put_task_struct(timer->it_process); |
| 865 | timer->it_process = NULL; |
| 866 | } |
| 867 | unlock_timer(timer, flags); |
| 868 | release_posix_timer(timer, IT_ID_SET); |
| 869 | return 0; |
| 870 | } |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 871 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | /* |
| 873 | * return timer owned by the process, used by exit_itimers |
| 874 | */ |
Arjan van de Ven | 858119e | 2006-01-14 13:20:43 -0800 | [diff] [blame] | 875 | static void itimer_delete(struct k_itimer *timer) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 876 | { |
| 877 | unsigned long flags; |
| 878 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | retry_delete: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 880 | spin_lock_irqsave(&timer->it_lock, flags); |
| 881 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 882 | if (timer_delete_hook(timer) == TIMER_RETRY) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | unlock_timer(timer, flags); |
| 884 | goto retry_delete; |
| 885 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 886 | list_del(&timer->list); |
| 887 | /* |
| 888 | * This keeps any tasks waiting on the spin lock from thinking |
| 889 | * they got something (see the lock code above). |
| 890 | */ |
| 891 | if (timer->it_process) { |
| 892 | if (timer->it_sigev_notify == (SIGEV_SIGNAL|SIGEV_THREAD_ID)) |
| 893 | put_task_struct(timer->it_process); |
| 894 | timer->it_process = NULL; |
| 895 | } |
| 896 | unlock_timer(timer, flags); |
| 897 | release_posix_timer(timer, IT_ID_SET); |
| 898 | } |
| 899 | |
| 900 | /* |
Roland McGrath | 25f407f | 2005-10-21 15:03:29 -0700 | [diff] [blame] | 901 | * This is called by do_exit or de_thread, only when there are no more |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 902 | * references to the shared signal_struct. |
| 903 | */ |
| 904 | void exit_itimers(struct signal_struct *sig) |
| 905 | { |
| 906 | struct k_itimer *tmr; |
| 907 | |
| 908 | while (!list_empty(&sig->posix_timers)) { |
| 909 | tmr = list_entry(sig->posix_timers.next, struct k_itimer, list); |
| 910 | itimer_delete(tmr); |
| 911 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 912 | } |
| 913 | |
Thomas Gleixner | becf8b5 | 2006-01-09 20:52:38 -0800 | [diff] [blame] | 914 | /* Not available / possible... functions */ |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 915 | int do_posix_clock_nosettime(const clockid_t clockid, struct timespec *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | { |
| 917 | return -EINVAL; |
| 918 | } |
| 919 | EXPORT_SYMBOL_GPL(do_posix_clock_nosettime); |
| 920 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 921 | int do_posix_clock_nonanosleep(const clockid_t clock, int flags, |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 922 | struct timespec *t, struct timespec __user *r) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | { |
| 924 | #ifndef ENOTSUP |
| 925 | return -EOPNOTSUPP; /* aka ENOTSUP in userland for POSIX */ |
| 926 | #else /* parisc does define it separately. */ |
| 927 | return -ENOTSUP; |
| 928 | #endif |
| 929 | } |
| 930 | EXPORT_SYMBOL_GPL(do_posix_clock_nonanosleep); |
| 931 | |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 932 | asmlinkage long sys_clock_settime(const clockid_t which_clock, |
| 933 | const struct timespec __user *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 934 | { |
| 935 | struct timespec new_tp; |
| 936 | |
| 937 | if (invalid_clockid(which_clock)) |
| 938 | return -EINVAL; |
| 939 | if (copy_from_user(&new_tp, tp, sizeof (*tp))) |
| 940 | return -EFAULT; |
| 941 | |
| 942 | return CLOCK_DISPATCH(which_clock, clock_set, (which_clock, &new_tp)); |
| 943 | } |
| 944 | |
| 945 | asmlinkage long |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 946 | sys_clock_gettime(const clockid_t which_clock, struct timespec __user *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | { |
| 948 | struct timespec kernel_tp; |
| 949 | int error; |
| 950 | |
| 951 | if (invalid_clockid(which_clock)) |
| 952 | return -EINVAL; |
| 953 | error = CLOCK_DISPATCH(which_clock, clock_get, |
| 954 | (which_clock, &kernel_tp)); |
| 955 | if (!error && copy_to_user(tp, &kernel_tp, sizeof (kernel_tp))) |
| 956 | error = -EFAULT; |
| 957 | |
| 958 | return error; |
| 959 | |
| 960 | } |
| 961 | |
| 962 | asmlinkage long |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 963 | sys_clock_getres(const clockid_t which_clock, struct timespec __user *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | { |
| 965 | struct timespec rtn_tp; |
| 966 | int error; |
| 967 | |
| 968 | if (invalid_clockid(which_clock)) |
| 969 | return -EINVAL; |
| 970 | |
| 971 | error = CLOCK_DISPATCH(which_clock, clock_getres, |
| 972 | (which_clock, &rtn_tp)); |
| 973 | |
| 974 | if (!error && tp && copy_to_user(tp, &rtn_tp, sizeof (rtn_tp))) { |
| 975 | error = -EFAULT; |
| 976 | } |
| 977 | |
| 978 | return error; |
| 979 | } |
| 980 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 981 | /* |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 982 | * nanosleep for monotonic and realtime clocks |
| 983 | */ |
| 984 | static int common_nsleep(const clockid_t which_clock, int flags, |
| 985 | struct timespec *tsave, struct timespec __user *rmtp) |
| 986 | { |
Oleg Nesterov | 080344b | 2008-02-01 17:29:05 +0300 | [diff] [blame] | 987 | return hrtimer_nanosleep(tsave, rmtp, flags & TIMER_ABSTIME ? |
| 988 | HRTIMER_MODE_ABS : HRTIMER_MODE_REL, |
| 989 | which_clock); |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 990 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 991 | |
| 992 | asmlinkage long |
Thomas Gleixner | a924b04 | 2006-01-09 20:52:27 -0800 | [diff] [blame] | 993 | sys_clock_nanosleep(const clockid_t which_clock, int flags, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | const struct timespec __user *rqtp, |
| 995 | struct timespec __user *rmtp) |
| 996 | { |
| 997 | struct timespec t; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | |
| 999 | if (invalid_clockid(which_clock)) |
| 1000 | return -EINVAL; |
| 1001 | |
| 1002 | if (copy_from_user(&t, rqtp, sizeof (struct timespec))) |
| 1003 | return -EFAULT; |
| 1004 | |
Thomas Gleixner | 5f82b2b | 2006-01-09 20:52:29 -0800 | [diff] [blame] | 1005 | if (!timespec_valid(&t)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1006 | return -EINVAL; |
| 1007 | |
Thomas Gleixner | 97735f2 | 2006-01-09 20:52:37 -0800 | [diff] [blame] | 1008 | return CLOCK_DISPATCH(which_clock, nsleep, |
| 1009 | (which_clock, flags, &t, rmtp)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1010 | } |
Toyo Abe | 1711ef3 | 2006-09-29 02:00:28 -0700 | [diff] [blame] | 1011 | |
| 1012 | /* |
| 1013 | * nanosleep_restart for monotonic and realtime clocks |
| 1014 | */ |
| 1015 | static int common_nsleep_restart(struct restart_block *restart_block) |
| 1016 | { |
| 1017 | return hrtimer_nanosleep_restart(restart_block); |
| 1018 | } |
| 1019 | |
| 1020 | /* |
| 1021 | * This will restart clock_nanosleep. This is required only by |
| 1022 | * compat_clock_nanosleep_restart for now. |
| 1023 | */ |
| 1024 | long |
| 1025 | clock_nanosleep_restart(struct restart_block *restart_block) |
| 1026 | { |
| 1027 | clockid_t which_clock = restart_block->arg0; |
| 1028 | |
| 1029 | return CLOCK_DISPATCH(which_clock, nsleep_restart, |
| 1030 | (restart_block)); |
| 1031 | } |