p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

perf/x86/intel: Use ULL constant to prevent undefined shift behaviour 

When x86_pmu.num_counters is 32 the shift of the integer constant 1 is
exceeding 32bit and therefor undefined behaviour.

Fix this by shifting 1ULL instead of 1.

Reported-by: CoverityScan CID#1192105 ("Bad bit shift operation")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: http://lkml.kernel.org/r/20170111114310.17928-1-colin.king@canonical.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Colin King 2017-01-11 11:43:10 +00:00 committed by Thomas Gleixner
parent 6d6daa2094
commit ad5013d569
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/x86/events/intel/core.c
View File

@ -3987,7 +3987,7 @@ __init int intel_pmu_init(void)
x86_pmu.num_counters, INTEL_PMC_MAX_GENERIC);
x86_pmu.num_counters = INTEL_PMC_MAX_GENERIC;
}
x86_pmu.intel_ctrl = (1 << x86_pmu.num_counters) - 1;
x86_pmu.intel_ctrl = (1ULL << x86_pmu.num_counters) - 1;
if (x86_pmu.num_counters_fixed > INTEL_PMC_MAX_FIXED) {
WARN(1, KERN_ERR "hw perf events fixed %d > max(%d), clipping!",