diff options
| author | Eric Dumazet <edumazet@google.com> | 2014-03-25 18:42:27 -0700 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-04-18 11:06:58 +0200 |
| commit | e3749adbcbf79583fb092fa1866a160f664912eb (patch) | |
| tree | ff1d6a82bca1d29e245a8af99739a7e66461510c /net/unix | |
| parent | d291aa322b32aa808e914996c7f234024e53432d (diff) | |
net: unix: non blocking recvmsg() should not return -EINTR
[ Upstream commit de1443916791d75fdd26becb116898277bb0273f ]
Some applications didn't expect recvmsg() on a non blocking socket
could return -EINTR. This possibility was added as a side effect
of commit b3ca9b02b00704 ("net: fix multithreaded signal handling in
unix recv routines").
To hit this bug, you need to be a bit unlucky, as the u->readlock
mutex is usually held for very small periods.
Fixes: b3ca9b02b00704 ("net: fix multithreaded signal handling in unix recv routines")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'net/unix')
| -rw-r--r-- | net/unix/af_unix.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index d7c1ac621a9..c3975bcf725 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1785,8 +1785,11 @@ static int unix_dgram_recvmsg(struct kiocb *iocb, struct socket *sock, goto out; err = mutex_lock_interruptible(&u->readlock); - if (err) { - err = sock_intr_errno(sock_rcvtimeo(sk, noblock)); + if (unlikely(err)) { + /* recvmsg() in non blocking mode is supposed to return -EAGAIN + * sk_rcvtimeo is not honored by mutex_lock_interruptible() + */ + err = noblock ? -EAGAIN : -ERESTARTSYS; goto out; } @@ -1911,6 +1914,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, struct unix_sock *u = unix_sk(sk); struct sockaddr_un *sunaddr = msg->msg_name; int copied = 0; + int noblock = flags & MSG_DONTWAIT; int check_creds = 0; int target; int err = 0; @@ -1926,7 +1930,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, goto out; target = sock_rcvlowat(sk, flags&MSG_WAITALL, size); - timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT); + timeo = sock_rcvtimeo(sk, noblock); /* Lock the socket to prevent queue disordering * while sleeps in memcpy_tomsg @@ -1938,8 +1942,11 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock, } err = mutex_lock_interruptible(&u->readlock); - if (err) { - err = sock_intr_errno(timeo); + if (unlikely(err)) { + /* recvmsg() in non blocking mode is supposed to return -EAGAIN + * sk_rcvtimeo is not honored by mutex_lock_interruptible() + */ + err = noblock ? -EAGAIN : -ERESTARTSYS; goto out; } |