This is a note to let you know that I've just added the patch titled
perf/x86/intel: Don't accidentally clear high bits in bdw_limit_period()
to the 4.4-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-don-t-accidentally-clear-high-bits-in-bdw_limit_period.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e5ea9b54a055619160bbfe527ebb7d7191823d66 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Sat, 17 Mar 2018 14:52:16 +0300
Subject: perf/x86/intel: Don't accidentally clear high bits in bdw_limit_period()
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
commit e5ea9b54a055619160bbfe527ebb7d7191823d66 upstream.
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@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/perf_event_intel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -2716,7 +2716,7 @@ static unsigned bdw_limit_period(struct
X86_CONFIG(.event=0xc0, .umask=0x01)) {
if (left < 128)
left = 128;
- left &= ~0x3fu;
+ left &= ~0x3fULL;
}
return left;
}
Patches currently in stable-queue which might be from dan.carpenter@xxxxxxxxxx are
queue-4.4/perf-x86-intel-don-t-accidentally-clear-high-bits-in-bdw_limit_period.patch
queue-4.4/staging-ncpfs-memory-corruption-in-ncp_read_kernel.patch