Fix two sort-of-false-positives in the xdpsock userspace part:
samples/bpf/xdpsock_user.c: In function 'main':
samples/bpf/xdpsock_user.c:1531:47: warning: 'tv_usec' may be used uninitialized in this function [-Wmaybe-uninitialized]
1531 | pktgen_hdr->tv_usec = htonl(tv_usec);
| ^~~~~~~~~~~~~~
samples/bpf/xdpsock_user.c:1500:26: note: 'tv_usec' was declared here
1500 | u32 idx, tv_sec, tv_usec;
| ^~~~~~~
samples/bpf/xdpsock_user.c:1530:46: warning: 'tv_sec' may be used uninitialized in this function [-Wmaybe-uninitialized]
1530 | pktgen_hdr->tv_sec = htonl(tv_sec);
| ^~~~~~~~~~~~~
samples/bpf/xdpsock_user.c:1500:18: note: 'tv_sec' was declared here
1500 | u32 idx, tv_sec, tv_usec;
| ^~~~~~
Both variables are always initialized when @opt_tstamp == true and
they're being used also only when @opt_tstamp == true. However, that
variable comes from the BSS and is being toggled from another
function. They can't be executed simultaneously to actually trigger
undefined behaviour, but purely technically it is a correct warning.
Just initialize them with zeroes.
Fixes: eb68db45b747 ("samples/bpf: xdpsock: Add timestamp for Tx-only operation")
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
Signed-off-by: Alexander Lobakin <alobakin@xxxxx>
---
samples/bpf/xdpsock_user.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 9747d47a0a8f..a6d8291c8b38 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -1497,7 +1497,7 @@ static void rx_drop_all(void)
static int tx_only(struct xsk_socket_info *xsk, u32 *frame_nb,
int batch_size, unsigned long tx_ns)
{
- u32 idx, tv_sec, tv_usec;
+ u32 idx, tv_sec = 0, tv_usec = 0;
unsigned int i;
while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) <
--
2.36.0
