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Commit 7cc23cd6 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf/x86/intel/lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNEL 



We should always have proper privileges when requesting kernel
data.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/20130503121256.230745028@chello.nl


[ Fix build error reported by fengguang.wu@intel.com, propagate error code back. ]
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/n/tip-v0x9ky3ahzr6nm3c6ilwrili@git.kernel.org
parent 6e15eb3b

arch/x86/kernel/cpu/perf_event_intel_lbr.c

+10 −3
Original line number Diff line number Diff line
@@ -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_filter(struct perf_event *event) 
	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_filter(struct perf_event *event) 
	 * 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 perf_event *event) 
	/*

	 * 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