[PATCH 5.12 178/363] SUNRPC: fix ternary sign expansion bug in tracing

From: Greg Kroah-Hartman
Date: Mon May 17 2021 - 10:24:10 EST


From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

[ Upstream commit cb579086536f6564f5846f89808ec394ef8b8621 ]

This code is supposed to pass negative "err" values for tracing but it
passes positive values instead. The problem is that the
trace_svcsock_tcp_send() function takes a long but "err" is an int and
"sent" is a u32. The negative is first type promoted to u32 so it
becomes a high positive then it is promoted to long and it stays
positive.

Fix this by casting "err" directly to long.

Fixes: 998024dee197 ("SUNRPC: Add more svcsock tracepoints")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sunrpc/svcsock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 2e2f007dfc9f..7cde41a936a4 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1171,7 +1171,7 @@ static int svc_tcp_sendto(struct svc_rqst *rqstp)
tcp_sock_set_cork(svsk->sk_sk, true);
err = svc_tcp_sendmsg(svsk->sk_sock, xdr, marker, &sent);
xdr_free_bvec(xdr);
- trace_svcsock_tcp_send(xprt, err < 0 ? err : sent);
+ trace_svcsock_tcp_send(xprt, err < 0 ? (long)err : sent);
if (err < 0 || sent != (xdr->len + sizeof(marker)))
goto out_close;
if (atomic_dec_and_test(&svsk->sk_sendqlen))
--
2.30.2