Commit-ID: 6fec64e1c92d5c715c6d0f50786daa7708266bde Gitweb: https://git.kernel.org/tip/6fec64e1c92d5c715c6d0f50786daa7708266bde Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Tue, 26 Jun 2018 15:21:31 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Mon, 2 Jul 2018 11:33:25 +0200
posix-timers: Make forward callback return s64 The posix timer ti_overrun handling is broken because the forwarding functions can return a huge number of overruns which does not fit in an int. As a consequence timer_getoverrun(2) and siginfo::si_overrun can turn into random number generators. As a first step to address that let the timer_forward() callbacks return the full 64 bit value. Cast it to (int) temporarily until k_itimer::ti_overrun is converted to 64bit and the conversion to user space visible values is sanitized. Reported-by: Team OWL337 <icy...@gmail.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Acked-by: John Stultz <john.stu...@linaro.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Michael Kerrisk <mtk.manpa...@gmail.com> Link: https://lkml.kernel.org/r/20180626132704.922098...@linutronix.de --- kernel/time/alarmtimer.c | 4 ++-- kernel/time/posix-timers.c | 6 +++--- kernel/time/posix-timers.h | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 639321bf2e39..78a3cc555823 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -581,11 +581,11 @@ static void alarm_timer_rearm(struct k_itimer *timr) * @timr: Pointer to the posixtimer data struct * @now: Current time to forward the timer against */ -static int alarm_timer_forward(struct k_itimer *timr, ktime_t now) +static s64 alarm_timer_forward(struct k_itimer *timr, ktime_t now) { struct alarm *alarm = &timr->it.alarm.alarmtimer; - return (int) alarm_forward(alarm, timr->it_interval, now); + return alarm_forward(alarm, timr->it_interval, now); } /** diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 80d59333c76e..db1d65963a57 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -645,11 +645,11 @@ static ktime_t common_hrtimer_remaining(struct k_itimer *timr, ktime_t now) return __hrtimer_expires_remaining_adjusted(timer, now); } -static int common_hrtimer_forward(struct k_itimer *timr, ktime_t now) +static s64 common_hrtimer_forward(struct k_itimer *timr, ktime_t now) { struct hrtimer *timer = &timr->it.real.timer; - return (int)hrtimer_forward(timer, now, timr->it_interval); + return hrtimer_forward(timer, now, timr->it_interval); } /* @@ -702,7 +702,7 @@ void common_timer_get(struct k_itimer *timr, struct itimerspec64 *cur_setting) * expiry time forward by intervals, so expiry is > now. */ if (iv && (timr->it_requeue_pending & REQUEUE_PENDING || sig_none)) - timr->it_overrun += kc->timer_forward(timr, now); + timr->it_overrun += (int)kc->timer_forward(timr, now); remaining = kc->timer_remaining(timr, now); /* Return 0 only, when the timer is expired and not pending */ diff --git a/kernel/time/posix-timers.h b/kernel/time/posix-timers.h index 151e28f5bf30..ddb21145211a 100644 --- a/kernel/time/posix-timers.h +++ b/kernel/time/posix-timers.h @@ -19,7 +19,7 @@ struct k_clock { void (*timer_get)(struct k_itimer *timr, struct itimerspec64 *cur_setting); void (*timer_rearm)(struct k_itimer *timr); - int (*timer_forward)(struct k_itimer *timr, ktime_t now); + s64 (*timer_forward)(struct k_itimer *timr, ktime_t now); ktime_t (*timer_remaining)(struct k_itimer *timr, ktime_t now); int (*timer_try_to_cancel)(struct k_itimer *timr); void (*timer_arm)(struct k_itimer *timr, ktime_t expires,
