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Message-Id: <20180804082703.344587471@linuxfoundation.org>
Date: Sat, 4 Aug 2018 11:00:13 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Kan Liang <kan.liang@...el.com>,
"Peter Zijlstra (Intel)" <peterz@...radead.org>,
Thomas Gleixner <tglx@...utronix.de>,
Linus Torvalds <torvalds@...ux-foundation.org>,
acme@...nel.org, eranian@...gle.com,
Ingo Molnar <mingo@...nel.org>,
Sasha Levin <alexander.levin@...rosoft.com>
Subject: [PATCH 4.4 024/124] perf/x86/intel/uncore: Correct fixed counter index check in generic code
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kan Liang <kan.liang@...el.com>
[ Upstream commit 4749f8196452eeb73cf2086a6a9705bae479d33d ]
There is no index which is bigger than UNCORE_PMC_IDX_FIXED. The only
exception is client IMC uncore, which has been specially handled.
For generic code, it is not correct to use >= to check fixed counter.
The code quality issue will bring problem when a new counter index is
introduced.
Signed-off-by: Kan Liang <kan.liang@...el.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: acme@...nel.org
Cc: eranian@...gle.com
Link: http://lkml.kernel.org/r/1525371913-10597-3-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
arch/x86/kernel/cpu/perf_event_intel_uncore.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -229,7 +229,7 @@ void uncore_perf_event_update(struct int
u64 prev_count, new_count, delta;
int shift;
- if (event->hw.idx >= UNCORE_PMC_IDX_FIXED)
+ if (event->hw.idx == UNCORE_PMC_IDX_FIXED)
shift = 64 - uncore_fixed_ctr_bits(box);
else
shift = 64 - uncore_perf_ctr_bits(box);
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