[U-Boot] [PATCH] net: Mark the ip_udp_hdr struct as packed

[Maxime Ripard <maxime.ripard@free-electrons.com>]

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)
-- 
2.13.0