From 8524423da9afc637167057dd69e1f52f6dbcc8e5 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Tue, 5 Nov 2019 12:48:19 +0100 Subject: [PATCH] net: avoid address-of-packed-member error MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit sandbox_defconfig does not compile using GCC 9.2.1: net/net.c: In function ‘net_process_received_packet’: net/net.c:1288:23: error: taking address of packed member of ‘struct ip_udp_hdr’ may result in an unaligned pointer value [-Werror=address-of-packed-member] 1288 | sumptr = (ushort *)&(ip->udp_src); | ^~~~~~~~~~~~~~ Avoid the error by using a u8 pointer instead of an u16 pointer and in-lining ntohs(). Simplify the checksumming of the last message byte. Signed-off-by: Heinrich Schuchardt Reviewed-by: Simon Goldschmidt Acked-by: Joe Hershberger --- net/net.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/net/net.c b/net/net.c index 5114364edd..5199d679a1 100644 --- a/net/net.c +++ b/net/net.c @@ -1271,7 +1271,7 @@ void net_process_received_packet(uchar *in_packet, int len) #ifdef CONFIG_UDP_CHECKSUM if (ip->udp_xsum != 0) { ulong xsum; - ushort *sumptr; + u8 *sumptr; ushort sumlen; xsum = ip->ip_p; @@ -1282,22 +1282,16 @@ void net_process_received_packet(uchar *in_packet, int len) xsum += (ntohl(ip->ip_dst.s_addr) >> 0) & 0x0000ffff; sumlen = ntohs(ip->udp_len); - sumptr = (ushort *)&(ip->udp_src); + sumptr = (u8 *)&ip->udp_src; while (sumlen > 1) { - ushort sumdata; - - sumdata = *sumptr++; - xsum += ntohs(sumdata); + /* inlined ntohs() to avoid alignment errors */ + xsum += (sumptr[0] << 8) + sumptr[1]; + sumptr += 2; sumlen -= 2; } - if (sumlen > 0) { - ushort sumdata; - - sumdata = *(unsigned char *)sumptr; - sumdata = (sumdata << 8) & 0xff00; - xsum += sumdata; - } + if (sumlen > 0) + xsum += (sumptr[0] << 8) + sumptr[0]; while ((xsum >> 16) != 0) { xsum = (xsum & 0x0000ffff) + ((xsum >> 16) & 0x0000ffff); -- 2.39.5