The -mno-unaligned-access flag used on ARM to prevent GCC from generating unaligned accesses (obviously) will only do so on packed structures.
It seems like gcc 7.1 is a bit stricter than previous gcc versions on this, and using it lead to data abort for unaligned accesses when generating network traffic.
Fix this by adding the packed attribute to the ip_udp_hdr structure in order to let GCC do its job.
Signed-off-by: Maxime Ripard maxime.ripard@free-electrons.com --- include/net.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/net.h b/include/net.h index 997db9210a8f..7b815afffafa 100644 --- a/include/net.h +++ b/include/net.h @@ -390,7 +390,7 @@ struct ip_udp_hdr { u16 udp_dst; /* UDP destination port */ u16 udp_len; /* Length of UDP packet */ u16 udp_xsum; /* Checksum */ -}; +} __attribute__ ((packed));
#define IP_UDP_HDR_SIZE (sizeof(struct ip_udp_hdr)) #define UDP_HDR_SIZE (IP_UDP_HDR_SIZE - IP_HDR_SIZE)