From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 11 Apr 2017 08:10:28 +0000 (+0200)
Subject: perf/x86: Avoid exposing wrong/stale data in intel_pmu_lbr_read_32()
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~13^2~39
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f42be33fe976d4c0812fb2f697543e1b5ac073be;p=firefly-linux-kernel-4.4.55.git

perf/x86: Avoid exposing wrong/stale data in intel_pmu_lbr_read_32()

commit f2200ac311302fcdca6556fd0c5127eab6c65a3e upstream.

When the perf_branch_entry::{in_tx,abort,cycles} fields were added,
intel_pmu_lbr_read_32() wasn't updated to initialize them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: 135c5612c460 ("perf/x86/intel: Support Haswell/v4 LBR format")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index 659f01e165d5..8900400230c6 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -410,6 +410,9 @@ static void intel_pmu_lbr_read_32(struct cpu_hw_events *cpuc)
 		cpuc->lbr_entries[i].to		= msr_lastbranch.to;
 		cpuc->lbr_entries[i].mispred	= 0;
 		cpuc->lbr_entries[i].predicted	= 0;
+		cpuc->lbr_entries[i].in_tx	= 0;
+		cpuc->lbr_entries[i].abort	= 0;
+		cpuc->lbr_entries[i].cycles	= 0;
 		cpuc->lbr_entries[i].reserved	= 0;
 	}
 	cpuc->lbr_stack.nr = i;