tls_sw_splice_read() takes its blocking behavior from
SPLICE_F_NONBLOCK alone. When splicing from a socket to a pipe,
do_splice() sets that flag from the pipe's O_NONBLOCK, not the
socket's. On a nonblocking socket, a splice(2) call without
SPLICE_F_NONBLOCK therefore sleeps in tls_rx_rec_wait() until a
record arrives. tcp_splice_read() instead reads sock->file->f_flags
and returns -EAGAIN.
Poll makes the sleep reachable. tls_sw_sock_is_readable() reports
the socket readable while any record sits on rx_list, including a
zero-length record that delivers no bytes to the pipe. The
strparser announces a record before decryption, when its plaintext
length is unknown, so the readiness test cannot screen such a
record out. The splice consumes it and waits for the next, and an
event loop that polls and then splices stalls every connection it
multiplexes.
Treat the socket's O_NONBLOCK as nonblocking too. A caller that
sets O_NONBLOCK and splices without SPLICE_F_NONBLOCK, taking that
flag to govern only the pipe, now gets -EAGAIN where it blocked
before. sendfile(2) from a TLS socket changes the same way, because
do_sendfile() leaves the input file's O_NONBLOCK out of the splice
flags. Both now behave as they do on a plain TCP socket.
Fixes: c46234ebb4d1 ("tls: RX path for ktls")
Signed-off-by: Chuck Lever <[email protected]>
---
net/tls/tls_sw.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index 79a807e51bc7..6ca1e9f4e504 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -2020,10 +2020,14 @@ ssize_t tls_sw_splice_read(struct socket *sock, loff_t
*ppos,
struct sk_buff *skb;
bool released = true;
ssize_t copied = 0;
+ bool nonblock;
int chunk;
int err;
- err = tls_rx_reader_lock(sk, ctx, flags & SPLICE_F_NONBLOCK);
+ nonblock = (flags & SPLICE_F_NONBLOCK) ||
+ (sock->file->f_flags & O_NONBLOCK);
+
+ err = tls_rx_reader_lock(sk, ctx, nonblock);
if (err < 0)
return err;
@@ -2038,8 +2042,7 @@ ssize_t tls_sw_splice_read(struct socket *sock, loff_t
*ppos,
} else {
struct tls_decrypt_arg darg;
- err = tls_rx_rec_wait(sk, flags & SPLICE_F_NONBLOCK,
- released, false);
+ err = tls_rx_rec_wait(sk, nonblock, released, false);
if (err <= 0)
goto splice_read_end;
@@ -2069,10 +2072,7 @@ ssize_t tls_sw_splice_read(struct socket *sock, loff_t
*ppos,
if (rxm->full_len == 0) {
consume_skb(skb);
if (signal_pending(current)) {
- long timeo;
-
- timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
- err = sock_intr_errno(timeo);
+ err = sock_intr_errno(sock_rcvtimeo(sk, nonblock));
goto splice_read_end;
}
goto retry;
--
2.55.0
