This is a note to let you know that I've just added the patch titled

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

to the 3.4-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     
perf-x86-intel-lbr-demand-proper-privileges-for-perf_sample_branch_kernel.patch
and it can be found in the queue-3.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 7cc23cd6c0c7d7f4bee057607e7ce01568925717 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <[email protected]>
Date: Fri, 3 May 2013 14:11:25 +0200
Subject: perf/x86/intel/lbr: Demand proper privileges for 
PERF_SAMPLE_BRANCH_KERNEL

From: Peter Zijlstra <[email protected]>

commit 7cc23cd6c0c7d7f4bee057607e7ce01568925717 upstream.

We should always have proper privileges when requesting kernel
data.

Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
[ Fix build error reported by [email protected], propagate error code 
back. ]
Signed-off-by: Ingo Molnar <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 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


Patches currently in stable-queue which might be from [email protected] are

queue-3.4/perf-x86-intel-lbr-demand-proper-privileges-for-perf_sample_branch_kernel.patch
queue-3.4/perf-x86-intel-lbr-fix-lbr-filter.patch
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