Messages in this thread Patch in this message |  | | From | Andi Kleen <> | Subject | [PATCH 08/29] perf, x86: Disable LBR recording for unknown LBR_FMT | Date | Thu, 17 Jan 2013 12:36:31 -0800 |
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From: Andi Kleen <ak@linux.intel.com>
When the LBR format is unknown disable LBR recording. This prevents crashes when the LBR address is misdecoded and mis-sign extended.
Signed-off-by: Andi Kleen <ak@linux.intel.com> --- arch/x86/kernel/cpu/perf_event_intel_lbr.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c index 2af6695b..ad5af13 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -13,6 +13,7 @@ enum { LBR_FORMAT_EIP = 0x02, LBR_FORMAT_EIP_FLAGS = 0x03, LBR_FORMAT_EIP_FLAGS2 = 0x04, + LBR_FORMAT_MAX_KNOWN = LBR_FORMAT_EIP_FLAGS2, }; /* @@ -392,7 +393,7 @@ int intel_pmu_setup_lbr_filter(struct perf_event *event) /* * no LBR on this PMU */ - if (!x86_pmu.lbr_nr) + if (!x86_pmu.lbr_nr || x86_pmu.intel_cap.lbr_format > LBR_FORMAT_MAX_KNOWN) return -EOPNOTSUPP; /* -- 1.7.7.6
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