[dpdk-dev] [PATCH v2] test-pmd: Fix pointer aliasing error

Michael Qiu qdy220091330 at gmail.com
Thu Dec 4 04:28:31 CET 2014


app/test-pmd/csumonly.c: In function ‘get_psd_sum’:
build/include/rte_ip.h:161: error: dereferencing pointer ‘u16’
        does break strict-aliasing rules
build/include/rte_ip.h:157: note: initialized from here
        ...

The root cause is that, compile enable strict aliasing by default,
while in function rte_raw_cksum() try to convert 'const char *'
to 'const uint16_t *'.

This patch is one workaround fix.

Signed-off-by: Michael Qiu <michael.qiu at intel.com>
---
 lib/librte_net/rte_ip.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
index 61e4457..f1c7087 100644
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -154,7 +154,8 @@ struct ipv4_hdr {
 static inline uint16_t
 rte_raw_cksum(const char *buf, size_t len)
 {
-	const uint16_t *u16 = (const uint16_t *)buf;
+	unsigned long ptr = (unsigned long)buf;
+	const uint16_t *u16 = (const uint16_t *)ptr;
 	uint32_t sum = 0;
 
 	while (len >= (sizeof(*u16) * 4)) {
-- 
1.9.3



More information about the dev mailing list