From 842dc1dbabb5e874550b52d896851e5e53e28a5f Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Fri, 29 Sep 2017 13:29:37 +1000 Subject: [PATCH] powerpc/watchdog: Do not panic from locked CPU's IPI handler The SMP watchdog will detect locked CPUs and IPI them to print a backtrace and registers. If panic on hard lockup is enabled, do not panic from this handler, because that can cause recursion into the IPI layer during the panic. The caller already panics in this case. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/watchdog.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c index 2f6eadd9408d..532a1adbe89b 100644 --- a/arch/powerpc/kernel/watchdog.c +++ b/arch/powerpc/kernel/watchdog.c @@ -97,8 +97,7 @@ static void wd_lockup_ipi(struct pt_regs *regs) else dump_stack(); - if (hardlockup_panic) - nmi_panic(regs, "Hard LOCKUP"); + /* Do not panic from here because that can recurse into NMI IPI layer */ } static void set_cpumask_stuck(const struct cpumask *cpumask, u64 tb) -- 2.11.0