From: Kan Liang kan.liang@linux.intel.com
[ Upstream commit ee139385432e919f4d1f59b80edbc073cdae1391 ]
An oops is triggered by the fuzzy test.
[ 327.853081] unchecked MSR access error: RDMSR from 0x70c at rIP: 0xffffffffc082c820 (uncore_msr_read_counter+0x10/0x50 [intel_uncore]) [ 327.853083] Call Trace: [ 327.853085] <IRQ> [ 327.853089] uncore_pmu_event_start+0x85/0x170 [intel_uncore] [ 327.853093] uncore_pmu_event_add+0x1a4/0x410 [intel_uncore] [ 327.853097] ? event_sched_in.isra.118+0xca/0x240
There are 2 GP counters for each CBOX, but the current code claims 4 counters. Accessing the invalid registers triggers the oops.
Fixes: 6e394376ee89 ("perf/x86/intel/uncore: Add Intel Icelake uncore support") Signed-off-by: Kan Liang kan.liang@linux.intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Link: https://lkml.kernel.org/r/20200925134905.8839-3-kan.liang@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/events/intel/uncore_snb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c index 300937cc8795b..3b70c2ff177c0 100644 --- a/arch/x86/events/intel/uncore_snb.c +++ b/arch/x86/events/intel/uncore_snb.c @@ -314,7 +314,7 @@ static struct intel_uncore_ops icl_uncore_msr_ops = {
static struct intel_uncore_type icl_uncore_cbox = { .name = "cbox", - .num_counters = 4, + .num_counters = 2, .perf_ctr_bits = 44, .perf_ctr = ICL_UNC_CBO_0_PER_CTR0, .event_ctl = SNB_UNC_CBO_0_PERFEVTSEL0,