From: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
[ Upstream commit 436864095a95fcc611c20c44a111985fa9848730 ]
Data passed to user-space with a (SOL_UDP, UDP_GRO) cmsg carries an
int (see udp_cmsg_recv), not a u16 value, as strace confirms:
recvmsg(8, {msg_name=...,
msg_iov=[{iov_base="\0\0..."..., iov_len=96000}],
msg_iovlen=1,
msg_control=[{cmsg_len=20, <-- sizeof(cmsghdr) + 4
cmsg_level=SOL_UDP,
cmsg_type=0x68}], <-- UDP_GRO
msg_controllen=24,
msg_flags=0}, 0) = 11200
Interpreting the data as an u16 value won't work on big-endian platforms.
Since it is too late to back out of this API decision [1], fix the test.
[1]: https://lore.kernel.org/netdev/20230131174601.203127-1-jakub@xxxxxxxxxxxxxx/
Fixes: 3327a9c46352 ("selftests: add functionals test for UDP GRO")
Suggested-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/testing/selftests/net/udpgso_bench_rx.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/net/udpgso_bench_rx.c b/tools/testing/selftests/net/udpgso_bench_rx.c
index 4058c7451e70d..f35a924d4a303 100644
--- a/tools/testing/selftests/net/udpgso_bench_rx.c
+++ b/tools/testing/selftests/net/udpgso_bench_rx.c
@@ -214,11 +214,10 @@ static void do_verify_udp(const char *data, int len)
static int recv_msg(int fd, char *buf, int len, int *gso_size)
{
- char control[CMSG_SPACE(sizeof(uint16_t))] = {0};
+ char control[CMSG_SPACE(sizeof(int))] = {0};
struct msghdr msg = {0};
struct iovec iov = {0};
struct cmsghdr *cmsg;
- uint16_t *gsosizeptr;
int ret;
iov.iov_base = buf;
@@ -237,8 +236,7 @@ static int recv_msg(int fd, char *buf, int len, int *gso_size)
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_UDP
&& cmsg->cmsg_type == UDP_GRO) {
- gsosizeptr = (uint16_t *) CMSG_DATA(cmsg);
- *gso_size = *gsosizeptr;
+ *gso_size = *(int *)CMSG_DATA(cmsg);
break;
}
}
--
2.39.2
