[PATCH 2/3] cpufreq: ppc: Fix integer overflow in expression

Geert Uytterhoeven geert+renesas at glider.be
Thu Apr 17 19:53:26 EST 2014


On 32-bit, "12 * NSEC_PER_SEC" doesn't fit in "unsigned long"
(NSEC_PER_SEC is a "long" constant), causing an integer overflow:

drivers/cpufreq/ppc-corenet-cpufreq.c: In function 'corenet_cpufreq_cpu_init':
drivers/cpufreq/ppc-corenet-cpufreq.c:211:9: warning: integer overflow in expression [-Woverflow]

Force the intermediate to be 64-bit by adding an "ULL" suffix to the
constant multiplier to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>
---
 drivers/cpufreq/ppc-corenet-cpufreq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/ppc-corenet-cpufreq.c b/drivers/cpufreq/ppc-corenet-cpufreq.c
index e78f9c806de4..53881d78a931 100644
--- a/drivers/cpufreq/ppc-corenet-cpufreq.c
+++ b/drivers/cpufreq/ppc-corenet-cpufreq.c
@@ -208,7 +208,7 @@ static int corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
 		per_cpu(cpu_data, i) = data;
 
 	policy->cpuinfo.transition_latency =
-				(12 * NSEC_PER_SEC) / fsl_get_sys_freq();
+				(12ULL * NSEC_PER_SEC) / fsl_get_sys_freq();
 	of_node_put(np);
 
 	return 0;
-- 
1.7.9.5



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