From c0daaf3f1f672defa3a45ca449b76d0e86c55892 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 18 May 2009 14:02:12 +1000 Subject: [PATCH] perf_counter: powerpc: initialize cpuhw pointer before use Commit 9e35ad38 ("perf_counter: Rework the perf counter disable/enable") added code to the powerpc hw_perf_enable (renamed from hw_perf_restore) to test cpuhw->disabled and return immediately if it is not set (i.e. if the PMU is already enabled). Unfortunately the test got added before cpuhw was initialized, resulting in an oops the first time hw_perf_enable got called. This fixes it by moving the initialization of cpuhw to before cpuhw->disabled is tested. [ Impact: fix oops-causing bug on powerpc ] Signed-off-by: Paul Mackerras Cc: Peter Zijlstra Cc: Corey Ashford LKML-Reference: <18960.56772.869734.304631@drongo.ozlabs.ibm.com> Signed-off-by: Ingo Molnar --- arch/powerpc/kernel/perf_counter.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/perf_counter.c b/arch/powerpc/kernel/perf_counter.c index 6baae5a5c331..fe21b2440f28 100644 --- a/arch/powerpc/kernel/perf_counter.c +++ b/arch/powerpc/kernel/perf_counter.c @@ -450,12 +450,11 @@ void hw_perf_enable(void) int idx; local_irq_save(flags); + cpuhw = &__get_cpu_var(cpu_hw_counters); if (!cpuhw->disabled) { local_irq_restore(flags); return; } - - cpuhw = &__get_cpu_var(cpu_hw_counters); cpuhw->disabled = 0; /* -- 2.30.2