Commit-ID: e5ea9b54a055619160bbfe527ebb7d7191823d66
Gitweb: https://git.kernel.org/tip/e5ea9b54a055619160bbfe527ebb7d7191823d66
Author: Dan Carpenter <dan.carpen...@oracle.com>
AuthorDate: Sat, 17 Mar 2018 14:52:16 +0300
Committer: Ingo Molnar <mi...@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.carpen...@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Cc: Alexander Shishkin <alexander.shish...@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Kan Liang <kan.li...@linux.intel.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Sebastian Andrzej Siewior <bige...@linutronix.de>
Cc: Stephane Eranian <eran...@google.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Vince Weaver <vincent.wea...@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 <mi...@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;
}
