[PATCH 3.18 53/57] perf/rapl: Fix crash in rapl_scale()

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Stephane Eranian <eranian@xxxxxxxxxx>

commit 98b008dff8452653909d9263efda925873e8d8bb upstream.

This patch fixes a systematic crash in rapl_scale()
due to an invalid pointer.

The bug was introduced by commit:

  89cbc76768c2 ("x86: Replace __get_cpu_var uses")

The fix is simple. Just put the parenthesis where it needs
to be, i.e., around rapl_pmu. To my surprise, the compiler
was not complaining about passing an integer instead of a
pointer.

Reported-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
Tested-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
Fixes: 89cbc76768c2 ("x86: Replace __get_cpu_var uses")
Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: cl@xxxxxxxxx
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20150122203834.GA10228@thinkpad
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kernel/cpu/perf_event_intel_rapl.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c
@@ -135,7 +135,7 @@ static inline u64 rapl_scale(u64 v)
 	 * or use ldexp(count, -32).
 	 * Watts = Joules/Time delta
 	 */
-	return v << (32 - __this_cpu_read(rapl_pmu->hw_unit));
+	return v << (32 - __this_cpu_read(rapl_pmu)->hw_unit);
 }
 
 static u64 rapl_event_update(struct perf_event *event)


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