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 xypron.glpk@gmx.de --- v2: reword commit message add a comment simplify checksumming of last byte --- net/net.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-)
diff --git a/net/net.c b/net/net.c index ded86e7456..bcb9d5f07e 100644 --- a/net/net.c +++ b/net/net.c @@ -1274,7 +1274,7 @@ 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; @@ -1285,22 +1285,16 @@ 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); -- 2.24.0.rc1