commit: 4b0c0f294f60abcdd20994a8341a95c8ac5eeb96 From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Date: Fri, 3 May 2013 15:02:50 +0200 Subject: tick: Cleanup NOHZ per cpu data on cpu down Prarit reported a crash on CPU offline/online. The reason is that on CPU down the NOHZ related per cpu data of the dead cpu is not cleaned up. If at cpu online an interrupt happens before the per cpu tick device is registered the irq_enter() check potentially sees stale data and dereferences a NULL pointer. Cleanup the data after the cpu is dead. Reported-by: Prarit Bhargava <prarit@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Cc: Mike Galbraith <bitbucket@xxxxxxxxx> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1305031451561.2886@ionos Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> --- kernel/time/tick-sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 225f8bf..0eed1db 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -904,7 +904,7 @@ void tick_cancel_sched_timer(int cpu) hrtimer_cancel(&ts->sched_timer); # endif - ts->nohz_mode = NOHZ_MODE_INACTIVE; + memset(ts, 0, sizeof(*ts)); } #endif -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html