Messages in this thread Patch in this message | | | Date | Sat, 20 Dec 2008 18:48:17 +0100 | From | Oleg Nesterov <> | Subject | [PATCH] posix-timers: CLOCK_MONOTONIC_RAW: fix the usage of ->it_clock |
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(compile tested)
common_timer_create() and common_timer_set() blindly pass ->it_clock to hrtimer_init() as clock_id. This used to work until CLOCK_MONOTONIC_RAW was introduced, now we should be careful.
Perhaps it makes sense to add BUG_ON(clock_id >= HRTIMER_MAX_CLOCK_BASES) to __hrtimer_init(), the wrong clock_id leads to catastrophe.
Reported-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
--- K-28/kernel/posix-timers.c~CLOCK_MONOTONIC_RAW 2008-12-02 17:12:40.000000000 +0100 +++ K-28/kernel/posix-timers.c 2008-12-20 18:23:28.000000000 +0100 @@ -191,12 +191,20 @@ static inline int common_clock_set(const return do_sys_settimeofday(tp, NULL); } -static int common_timer_create(struct k_itimer *new_timer) +static inline int +__common_timer_init(struct k_itimer *timer, enum hrtimer_mode mode) { - hrtimer_init(&new_timer->it.real.timer, new_timer->it_clock, 0); + clockid_t clock_id = timer->it_clock ? + CLOCK_MONOTONIC : CLOCK_REALTIME; + hrtimer_init(&timer->it.real.timer, clock_id, mode); return 0; } +static int common_timer_create(struct k_itimer *new_timer) +{ + return __common_timer_init(new_timer, HRTIMER_MODE_ABS); +} + /* * Return nonzero if we know a priori this clockid_t value is bogus. */ @@ -730,7 +738,7 @@ common_timer_set(struct k_itimer *timr, return 0; mode = flags & TIMER_ABSTIME ? HRTIMER_MODE_ABS : HRTIMER_MODE_REL; - hrtimer_init(&timr->it.real.timer, timr->it_clock, mode); + __common_timer_init(timr, mode); timr->it.real.timer.function = posix_timer_fn; hrtimer_set_expires(timer, timespec_to_ktime(new_setting->it_value));
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