From 711bd207a233141308d0aea0d2e286ee6b4b23cd Mon Sep 17 00:00:00 2001 From: Madhavan Srinivasan Date: Wed, 16 Aug 2017 21:51:34 +0530 Subject: [PATCH] powerpc/perf: Fix usage of nest_imc_refc nest_imc_refc is a reference count struct, used to track number of active perf sessions using the nest units. Currently the code accesses nest_imc_refc using node_id, which is incorrect, the array is indexed by node number. Meaning in the case of sparse node ids we index off the end of the array. Fix it to use get_nest_pmu_ref() which uses the existing per-cpu variable local_nest_imc_refc. Fixes: 885dcd709ba91 ('powerpc/perf: Add nest IMC PMU support') Reported-by: Dan Carpenter Signed-off-by: Madhavan Srinivasan [mpe: Tweak change log] Signed-off-by: Michael Ellerman --- arch/powerpc/perf/imc-pmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c index a8f95f96d54b..9ccac86f3463 100644 --- a/arch/powerpc/perf/imc-pmu.c +++ b/arch/powerpc/perf/imc-pmu.c @@ -404,7 +404,7 @@ static void nest_imc_counters_release(struct perf_event *event) rc = opal_imc_counters_stop(OPAL_IMC_COUNTERS_NEST, get_hard_smp_processor_id(event->cpu)); if (rc) { - mutex_unlock(&nest_imc_refc[node_id].lock); + mutex_unlock(&ref->lock); pr_err("nest-imc: Unable to stop the counters for core %d\n", node_id); return; } @@ -487,7 +487,7 @@ static int nest_imc_event_init(struct perf_event *event) rc = opal_imc_counters_start(OPAL_IMC_COUNTERS_NEST, get_hard_smp_processor_id(event->cpu)); if (rc) { - mutex_unlock(&nest_imc_refc[node_id].lock); + mutex_unlock(&ref->lock); pr_err("nest-imc: Unable to start the counters for node %d\n", node_id); return rc; -- 2.20.1