posix-cpu-timers: Pass the task into arm_timer()

The task has been already computed to take siglock before calling
arm_timer. So pass the benefit of that labor into arm_timer().

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/8736auvdt1.fsf@x220.int.ebiederm.org

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 40c2d83..ef936c5 100644 (file)
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -482,12 +482,11 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk)
  * Insert the timer on the appropriate list before any timers that
  * expire later.  This must be called with the sighand lock held.
  */
-static void arm_timer(struct k_itimer *timer)
+static void arm_timer(struct k_itimer *timer, struct task_struct *p)
 {
        int clkidx = CPUCLOCK_WHICH(timer->it_clock);
        struct cpu_timer *ctmr = &timer->it.cpu;
        u64 newexp = cpu_timer_getexpires(ctmr);
-       struct task_struct *p = ctmr->task;
        struct posix_cputimer_base *base;
 
        if (CPUCLOCK_PERTHREAD(timer->it_clock))
@@ -660,7 +659,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
         */
        cpu_timer_setexpires(ctmr, new_expires);
        if (new_expires != 0 && val < new_expires) {
-               arm_timer(timer);
+               arm_timer(timer, p);
        }
 
        unlock_task_sighand(p, &flags);
@@ -980,7 +979,7 @@ static void posix_cpu_timer_rearm(struct k_itimer *timer)
        /*
         * Now re-arm for the new expiry time.
         */
-       arm_timer(timer);
+       arm_timer(timer, p);
        unlock_task_sighand(p, &flags);
 }