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| author | Eric Dumazet <edumazet@google.com> | 2019-12-06 09:38:36 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-12-06 12:06:44 -0800 |
| commit | 1af66221a66de080274540a5c481ddacbe3574d2 (patch) | |
| tree | a590d14576eeb53502e7d98d3a222e2368099c59 | |
| parent | 462f8554a89643dcd0981790101a31a01aa812fe (diff) | |
| download | linux-stable-1af66221a66de080274540a5c481ddacbe3574d2.tar.gz linux-stable-1af66221a66de080274540a5c481ddacbe3574d2.tar.bz2 linux-stable-1af66221a66de080274540a5c481ddacbe3574d2.zip | |
net: avoid an indirect call in ____sys_recvmsg()
CONFIG_RETPOLINE=y made indirect calls expensive.
gcc seems to add an indirect call in ____sys_recvmsg().
Rewriting the code slightly makes sure to avoid this indirection.
Alternative would be to not call sock_recvmsg() and instead
use security_socket_recvmsg() and sock_recvmsg_nosec(),
but this is less readable IMO.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: David Laight <David.Laight@aculab.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/socket.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/socket.c b/net/socket.c index ea28cbb9e2e7..5af84d71cbc2 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2559,7 +2559,12 @@ static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys, if (sock->file->f_flags & O_NONBLOCK) flags |= MSG_DONTWAIT; - err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys, flags); + + if (unlikely(nosec)) + err = sock_recvmsg_nosec(sock, msg_sys, flags); + else + err = sock_recvmsg(sock, msg_sys, flags); + if (err < 0) goto out; len = err; |