[PATCH net-next v1 3/9] net: devmem: preserve sockc_err

Mina Almasry
2025-05-19T02:35:25Z

Preserve the error code returned by sock_cmsg_send and return that on
err.

Signed-off-by: Mina Almasry <almasrymina@google.com>
---
net/ipv4/tcp.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index b7b6ab41b496..45abe5772157 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1067,7 +1067,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
int flags, err, copied = 0;
int mss_now = 0, size_goal, copied_syn = 0;
int process_backlog = 0;
- bool sockc_valid = true;
+ int sockc_err = 0;
int zc = 0;
long timeo;

@@ -1075,13 +1075,10 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)

sockc = (struct sockcm_cookie){ .tsflags = READ_ONCE(sk->sk_tsflags) };
if (msg->msg_controllen) {
- err = sock_cmsg_send(sk, msg, &sockc);
- if (unlikely(err))
- /* Don't return error until MSG_FASTOPEN has been
- * processed; that may succeed even if the cmsg is
- * invalid.
- */
- sockc_valid = false;
+ sockc_err = sock_cmsg_send(sk, msg, &sockc);
+ /* Don't return error until MSG_FASTOPEN has been processed;
+ * that may succeed even if the cmsg is invalid.
+ */
}

if ((flags & MSG_ZEROCOPY) && size) {
@@ -1092,7 +1089,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
} else if (sock_flag(sk, SOCK_ZEROCOPY)) {
skb = tcp_write_queue_tail(sk);
uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb),
- sockc_valid && !!sockc.dmabuf_id);
+ !sockc_err && !!sockc.dmabuf_id);
if (!uarg) {
err = -ENOBUFS;
goto out_err;
@@ -1102,7 +1099,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
else
uarg_to_msgzc(uarg)->zerocopy = 0;

- if (sockc_valid && sockc.dmabuf_id) {
+ if (!sockc_err && sockc.dmabuf_id) {
binding = net_devmem_get_binding(sk, sockc.dmabuf_id);
if (IS_ERR(binding)) {
err = PTR_ERR(binding);
@@ -1116,7 +1113,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
zc = MSG_SPLICE_PAGES;
}

- if (sockc_valid && sockc.dmabuf_id &&
+ if (!sockc_err && sockc.dmabuf_id &&
(!(flags & MSG_ZEROCOPY) || !sock_flag(sk, SOCK_ZEROCOPY))) {
err = -EINVAL;
goto out_err;
@@ -1160,9 +1157,8 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
/* 'common' sending to sendq */
}

- if (!sockc_valid) {
- if (!err)
- err = -EINVAL;
+ if (!!sockc_err) {
+ err = sockc_err;
goto out_err;
}

--
2.49.0.1101.gccaa498523-goog