From f4b41f062c424209e3939a81e6da022e049a45f2 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Mon, 4 Apr 2022 18:30:22 +0200 Subject: net: remove noblock parameter from skb_recv_datagram() skb_recv_datagram() has two parameters 'flags' and 'noblock' that are merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)' As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags' into 'flags' and 'noblock' with finally obsolete bit operations like this: skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &rc); And this is not even done consistently with the 'flags' parameter. This patch removes the obsolete and costly splitting into two parameters and only performs bit operations when really needed on the caller side. One missing conversion thankfully reported by kernel test robot. I missed to enable kunit tests to build the mctp code. Reported-by: kernel test robot Signed-off-by: Oliver Hartkopp Signed-off-by: David S. Miller --- net/unix/af_unix.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index e71a312faa1e..fecbd95da918 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1643,7 +1643,8 @@ static int unix_accept(struct socket *sock, struct socket *newsock, int flags, * so that no locks are necessary. */ - skb = skb_recv_datagram(sk, 0, flags&O_NONBLOCK, &err); + skb = skb_recv_datagram(sk, (flags & O_NONBLOCK) ? MSG_DONTWAIT : 0, + &err); if (!skb) { /* This means receive shutdown. */ if (err == 0) @@ -2500,7 +2501,7 @@ static int unix_read_sock(struct sock *sk, read_descriptor_t *desc, int used, err; mutex_lock(&u->iolock); - skb = skb_recv_datagram(sk, 0, 1, &err); + skb = skb_recv_datagram(sk, MSG_DONTWAIT, &err); mutex_unlock(&u->iolock); if (!skb) return err; -- cgit From ec095263a965720e1ca39db1d9c5cd47846c789b Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Mon, 11 Apr 2022 14:49:55 +0200 Subject: net: remove noblock parameter from recvmsg() entities The internal recvmsg() functions have two parameters 'flags' and 'noblock' that were merged inside skb_recv_datagram(). As a follow up patch to commit f4b41f062c42 ("net: remove noblock parameter from skb_recv_datagram()") this patch removes the separate 'noblock' parameter for recvmsg(). Analogue to the referenced patch for skb_recv_datagram() the 'flags' and 'noblock' parameters are unnecessarily split up with e.g. err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len); or in err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg, sk, msg, size, flags & MSG_DONTWAIT, flags & ~MSG_DONTWAIT, &addr_len); instead of simply using only flags all the time and check for MSG_DONTWAIT where needed (to preserve for the formerly separated no(n)block condition). Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/r/20220411124955.154876-1-socketcan@hartkopp.net Signed-off-by: Paolo Abeni --- net/unix/af_unix.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index fecbd95da918..e1dd9e9c8452 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2484,8 +2484,7 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t si const struct proto *prot = READ_ONCE(sk->sk_prot); if (prot != &unix_dgram_proto) - return prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT, - flags & ~MSG_DONTWAIT, NULL); + return prot->recvmsg(sk, msg, size, flags, NULL); #endif return __unix_dgram_recvmsg(sk, msg, size, flags); } @@ -2917,8 +2916,7 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg, const struct proto *prot = READ_ONCE(sk->sk_prot); if (prot != &unix_stream_proto) - return prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT, - flags & ~MSG_DONTWAIT, NULL); + return prot->recvmsg(sk, msg, size, flags, NULL); #endif return unix_stream_read_generic(&state, true); } -- cgit From b146cbf2e32f01f56244d670aef2f43d44fcf120 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 10 May 2022 15:46:26 -0700 Subject: af_unix: Silence randstruct GCC plugin warning While preparing for Clang randstruct support (which duplicated many of the warnings the randstruct GCC plugin warned about), one strange one remained only for the randstruct GCC plugin. Eliminating this rids the plugin of the last exception. It seems the plugin is happy to dereference individual members of a cross-struct cast, but it is upset about casting to a whole object pointer. This only manifests in one place in the kernel, so just replace the variable with individual member accesses. There is no change in executable instruction output. Drop the last exception from the randstruct GCC plugin. Cc: "David S. Miller" Cc: Christoph Hellwig Cc: Paolo Abeni Cc: Alexei Starovoitov Cc: Cong Wang Cc: Al Viro Cc: netdev@vger.kernel.org Cc: linux-hardening@vger.kernel.org Acked-by: Kuniyuki Iwashima Link: https://lore.kernel.org/lkml/20220511022217.58586-1-kuniyu@amazon.co.jp Acked-by: Jakub Kicinski Link: https://lore.kernel.org/lkml/20220511151542.4cb3ff17@kernel.org Signed-off-by: Kees Cook --- net/unix/af_unix.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index e71a312faa1e..36367e7e3e0a 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1808,11 +1808,9 @@ static int maybe_init_creds(struct scm_cookie *scm, static bool unix_skb_scm_eq(struct sk_buff *skb, struct scm_cookie *scm) { - const struct unix_skb_parms *u = &UNIXCB(skb); - - return u->pid == scm->pid && - uid_eq(u->uid, scm->creds.uid) && - gid_eq(u->gid, scm->creds.gid) && + return UNIXCB(skb).pid == scm->pid && + uid_eq(UNIXCB(skb).uid, scm->creds.uid) && + gid_eq(UNIXCB(skb).gid, scm->creds.gid) && unix_secdata_eq(scm, skb); } -- cgit