[dpdk-dev] [PATCH] eal: fix macros to align value

Harman Kalra hkalra at marvell.com
Tue Jun 9 21:17:05 CEST 2020


Found an issue while using RTE_ALIGN_MUL_NEAR with an
expression, like as passed in estimate_tsc_freq().
RTE_ALIGN_MUL_FLOOR resulted in unexpected value in the
above function as division has more precedence over
substraction.

Fixes: 5120203d753f ("eal: add macros to align value to multiple")
Cc: stable at dpdk.org

Signed-off-by: Harman Kalra <hkalra at marvell.com>
---
 lib/librte_eal/include/rte_common.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/librte_eal/include/rte_common.h b/lib/librte_eal/include/rte_common.h
index 0843ce69e..0d834001c 100644
--- a/lib/librte_eal/include/rte_common.h
+++ b/lib/librte_eal/include/rte_common.h
@@ -295,7 +295,7 @@ static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
  * than the first parameter.
  */
 #define RTE_ALIGN_MUL_CEIL(v, mul) \
-	(((v + (typeof(v))(mul) - 1) / ((typeof(v))(mul))) * (typeof(v))(mul))
+	((((v) + (typeof(v))(mul) - 1) / ((typeof(v))(mul))) * (typeof(v))(mul))
 
 /**
  * Macro to align a value to the multiple of given value. The resultant
@@ -303,7 +303,7 @@ static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
  * than the first parameter.
  */
 #define RTE_ALIGN_MUL_FLOOR(v, mul) \
-	((v / ((typeof(v))(mul))) * (typeof(v))(mul))
+	(((v) / ((typeof(v))(mul))) * (typeof(v))(mul))
 
 /**
  * Macro to align value to the nearest multiple of the given value.
@@ -314,7 +314,7 @@ static void __attribute__((destructor(RTE_PRIO(prio)), used)) func(void)
 	({							\
 		typeof(v) ceil = RTE_ALIGN_MUL_CEIL(v, mul);	\
 		typeof(v) floor = RTE_ALIGN_MUL_FLOOR(v, mul);	\
-		(ceil - v) > (v - floor) ? floor : ceil;	\
+		(ceil - (v)) > ((v) - floor) ? floor : ceil;	\
 	})
 
 /**
-- 
2.18.0



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