3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> commit 7cc23cd6c0c7d7f4bee057607e7ce01568925717 upstream. We should always have proper privileges when requesting kernel data. Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: eranian@xxxxxxxxxx Link: http://lkml.kernel.org/r/20130503121256.230745028@xxxxxxxxx [ Fix build error reported by fengguang.wu@xxxxxxxxx, propagate error code back. ] Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Link: http://lkml.kernel.org/n/tip-v0x9ky3ahzr6nm3c6ilwrili@xxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/perf_event_intel_lbr.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -310,7 +310,7 @@ void intel_pmu_lbr_read(void) * - in case there is no HW filter * - in case the HW filter has errata or limitations */ -static void intel_pmu_setup_sw_lbr_filter(struct perf_event *event) +static int intel_pmu_setup_sw_lbr_filter(struct perf_event *event) { u64 br_type = event->attr.branch_sample_type; int mask = 0; @@ -318,8 +318,11 @@ static void intel_pmu_setup_sw_lbr_filte if (br_type & PERF_SAMPLE_BRANCH_USER) mask |= X86_BR_USER; - if (br_type & PERF_SAMPLE_BRANCH_KERNEL) + if (br_type & PERF_SAMPLE_BRANCH_KERNEL) { + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) + return -EACCES; mask |= X86_BR_KERNEL; + } /* we ignore BRANCH_HV here */ @@ -339,6 +342,8 @@ static void intel_pmu_setup_sw_lbr_filte * be used by fixup code for some CPU */ event->hw.branch_reg.reg = mask; + + return 0; } /* @@ -386,7 +391,9 @@ int intel_pmu_setup_lbr_filter(struct pe /* * setup SW LBR filter */ - intel_pmu_setup_sw_lbr_filter(event); + ret = intel_pmu_setup_sw_lbr_filter(event); + if (ret) + return ret; /* * setup HW LBR filter, if any -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html