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authorMartin Kepplinger <martink@posteo.de>2015-11-07 03:31:08 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-07 04:50:42 +0300
commit78e3c7951021b4e1a554b3d619506b55b0619073 (patch)
tree551b6effe854c1a463140f79ad80ccb685d344f6
parent06d8f8178c5709ff21cfbe16b6c078d2669b6e80 (diff)
downloadlinux-78e3c7951021b4e1a554b3d619506b55b0619073.tar.xz
arch/x86/kernel/cpu/perf_event_msr.c: use sign_extend64() for sign extension
Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: George Spelvin <linux@horizon.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Maxime Coquelin <maxime.coquelin@st.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Yury Norov <yury.norov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/x86/kernel/cpu/perf_event_msr.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_msr.c b/arch/x86/kernel/cpu/perf_event_msr.c
index f32ac13934f2..ec863b9a9f78 100644
--- a/arch/x86/kernel/cpu/perf_event_msr.c
+++ b/arch/x86/kernel/cpu/perf_event_msr.c
@@ -163,10 +163,9 @@ again:
goto again;
delta = now - prev;
- if (unlikely(event->hw.event_base == MSR_SMI_COUNT)) {
- delta <<= 32;
- delta >>= 32; /* sign extend */
- }
+ if (unlikely(event->hw.event_base == MSR_SMI_COUNT))
+ delta = sign_extend64(delta, 31);
+
local64_add(now - prev, &event->count);
}