From: Paul Mackerras Date: Mon, 18 May 2009 04:02:12 +0000 (+1000) Subject: perf_counter: powerpc: initialize cpuhw pointer before use X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c0daaf3f1f672defa3a45ca449b76d0e86c55892;p=linux-beck.git 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 --- 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; /*