io_uring/zcrx: warn on a repeated area append

isilence · axboe · commit f0b92207a00c · 2026-04-01T10:21:13.000-06:00
We only support a single area, no path should be able to call io_zcrx_append_area() twice. Warn if that happens instead of just returning an error. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/28eb67fb8c48445584d7c247a36e1ad8800f0c8b.1774261953.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
@@ -423,7 +423,7 @@ static void io_zcrx_free_area(struct io_zcrx_ifq *ifq,
 static int io_zcrx_append_area(struct io_zcrx_ifq *ifq,
 				struct io_zcrx_area *area)
 {
-	if (ifq->area)
+	if (WARN_ON_ONCE(ifq->area))
 		return -EINVAL;
 	ifq->area = area;
 	return 0;

Original file line number	Diff line number	Diff line change
`@@ -423,7 +423,7 @@ static void io_zcrx_free_area(struct io_zcrx_ifq *ifq,`
`423`	`423`	`static int io_zcrx_append_area(struct io_zcrx_ifq *ifq,`
`424`	`424`	`struct io_zcrx_area *area)`
`425`	`425`	`{`
`426`		`- if (ifq->area)`
	`426`	`+ if (WARN_ON_ONCE(ifq->area))`
`427`	`427`	`return -EINVAL;`
`428`	`428`	`ifq->area = area;`
`429`	`429`	`return 0;`