Thread (53 messages) 53 messages, 3 authors, 2016-07-26
STALE3620d

[PATCH 3.14 37/53] perf/x86: Fix undefined shift on 32-bit kernels

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2016-07-25 21:13:36
Also in: lkml

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

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

From: Andrey Ryabinin <redacted>

commit 6d6f2833bfbf296101f9f085e10488aef2601ba5 upstream.

Jim reported:

	UBSAN: Undefined behaviour in arch/x86/events/intel/core.c:3708:12
	shift exponent 35 is too large for 32-bit type 'long unsigned int'

The use of 'unsigned long' type obviously is not correct here, make it
'unsigned long long' instead.

Reported-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrey Ryabinin <redacted>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <redacted>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Imre Palik <redacted>
Cc: Jiri Olsa <redacted>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <redacted>
Cc: Thomas Gleixner <redacted>
Cc: Vince Weaver <redacted>
Fixes: 2c33645d366d ("perf/x86: Honor the architectural performance monitoring version")
Link: http://lkml.kernel.org/r/1462974711-10037-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Christopher <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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
@@ -2611,7 +2611,7 @@ __init int intel_pmu_init(void)
 				c->idxmsk64 |= (1ULL << x86_pmu.num_counters) - 1;
 			}
 			c->idxmsk64 &=
-				~(~0UL << (INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed));
+				~(~0ULL << (INTEL_PMC_IDX_FIXED + x86_pmu.num_counters_fixed));
 			c->weight = hweight64(c->idxmsk64);
 		}
 	}

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