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> --- lib/librte_net/rte_ether.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h index 3a87ff184900..ac8897681aca 100644 --- a/lib/librte_net/rte_ether.h +++ b/lib/librte_net/rte_ether.h @@ -55,7 +55,8 @@ extern "C" { * See http://standards.ieee.org/regauth/groupmac/tutorial.html */ struct ether_addr { - uint8_t addr_bytes[ETHER_ADDR_LEN]; /**< Addr bytes in tx order */ + /** Addr bytes in tx order */ + uint8_t addr_bytes[ETHER_ADDR_LEN] __rte_aligned(2); } __attribute__((__packed__)); #define ETHER_LOCAL_ADMIN_ADDR 0x02 /**< Locally assigned Eth. address. */ @@ -146,7 +147,7 @@ static inline int is_multicast_ether_addr(const struct ether_addr *ea) */ static inline int is_broadcast_ether_addr(const struct 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