From: Bruce Richardson <bruce.richard...@intel.com> When including the rte_ether.h header in applications with warnings enabled, a warning was given because of the assumption of 2-byte alignment of ethernet addresses when processing them.
.../include/rte_ether.h:149:2: warning: converting a packed ‘const struct ether_addr’ pointer (alignment 1) to a ‘unaligned_uint16_t’ {aka ‘const short unsigned int’} pointer (alignment 2) may result in an unaligned pointer value [-Waddress-of-packed-member] 149 | const unaligned_uint16_t *ea_words = (const unaligned_uint16_t *)ea; | ^~~~~ Since ethernet addresses should always be aligned on a two-byte boundary, we can just inform the compiler of this assumption to remove the warnings and allow us to always access the addresses using 16-bit operations. Signed-off-by: Bruce Richardson <bruce.richard...@intel.com> Signed-off-by: Stephen Hemminger <step...@networkplumber.org> Reviewed-by: Andrew Rybchenko <arybche...@solarflare.com> --- lib/librte_net/rte_ether.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h index feb35a33c94b..d7b76ddf63eb 100644 --- a/lib/librte_net/rte_ether.h +++ b/lib/librte_net/rte_ether.h @@ -58,7 +58,8 @@ extern "C" { * See http://standards.ieee.org/regauth/groupmac/tutorial.html */ struct rte_ether_addr { - uint8_t addr_bytes[RTE_ETHER_ADDR_LEN]; /**< Addr bytes in tx order */ + uint8_t addr_bytes[RTE_ETHER_ADDR_LEN] __rte_aligned(2); + /**< Addr bytes in tx order */ } __attribute__((__packed__)); #define RTE_ETHER_LOCAL_ADMIN_ADDR 0x02 /**< Locally assigned Eth. address. */ @@ -81,8 +82,8 @@ struct rte_ether_addr { static inline int rte_is_same_ether_addr(const struct rte_ether_addr *ea1, const struct rte_ether_addr *ea2) { - const unaligned_uint16_t *w1 = (const uint16_t *)ea1; - const unaligned_uint16_t *w2 = (const uint16_t *)ea2; + const uint16_t *w1 = (const uint16_t *)ea1; + const uint16_t *w2 = (const uint16_t *)ea2; return ((w1[0] ^ w2[0]) | (w1[1] ^ w2[1]) | (w1[2] ^ w2[2])) == 0; } @@ -99,7 +100,7 @@ static inline int rte_is_same_ether_addr(const struct rte_ether_addr *ea1, */ static inline int rte_is_zero_ether_addr(const struct rte_ether_addr *ea) { - const unaligned_uint16_t *w = (const uint16_t *)ea; + const uint16_t *w = (const uint16_t *)ea; return (w[0] | w[1] | w[2]) == 0; } @@ -146,7 +147,7 @@ static inline int rte_is_multicast_ether_addr(const struct rte_ether_addr *ea) */ static inline int rte_is_broadcast_ether_addr(const struct rte_ether_addr *ea) { - const unaligned_uint16_t *ea_words = (const unaligned_uint16_t *)ea; + const uint16_t *ea_words = (const uint16_t *)ea; return (ea_words[0] == 0xFFFF && ea_words[1] == 0xFFFF && ea_words[2] == 0xFFFF); -- 2.20.1