* [tip:perf/urgent] perf/x86/intel: Don't accidentally clear high bits in bdw_limit_period()
[not found] <20180317115216.GB4035@mwanda>
@ 2018-03-20 11:15 ` tip-bot for Dan Carpenter
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From: tip-bot for Dan Carpenter @ 2018-03-20 11:15 UTC (permalink / raw)
To: linux-tip-commits
Cc: hpa, peterz, linux-kernel, dan.carpenter, alexander.shishkin,
tglx, acme, eranian, kan.liang, vincent.weaver, torvalds, mingo,
bigeasy, jolsa
Commit-ID: e5ea9b54a055619160bbfe527ebb7d7191823d66
Gitweb: https://git.kernel.org/tip/e5ea9b54a055619160bbfe527ebb7d7191823d66
Author: Dan Carpenter <dan.carpenter@oracle.com>
AuthorDate: Sat, 17 Mar 2018 14:52:16 +0300
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 20 Mar 2018 08:53:31 +0100
perf/x86/intel: Don't accidentally clear high bits in bdw_limit_period()
We intended to clear the lowest 6 bits but because of a type bug we
clear the high 32 bits as well. Andi says that periods are rarely more
than U32_MAX so this bug probably doesn't have a huge runtime impact.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 294fe0f52a44 ("perf/x86/intel: Add INST_RETIRED.ALL workarounds")
Link: http://lkml.kernel.org/r/20180317115216.GB4035@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/events/intel/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 56457cb73448..9b18a227fff7 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3194,7 +3194,7 @@ static unsigned bdw_limit_period(struct perf_event *event, unsigned left)
X86_CONFIG(.event=0xc0, .umask=0x01)) {
if (left < 128)
left = 128;
- left &= ~0x3fu;
+ left &= ~0x3fULL;
}
return left;
}
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