[PATCH 021/109] net: socket: add do_sys_recvmmsg() helper; remove in-kernel call to syscall
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: 2018-03-29 11:52:42
Also in:
linux-arch, lkml
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
Using the net-internal helper do_sys_recvmmsg() allows us to avoid the internal calls to the sys_getsockopt() syscall. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net Cc: David S. Miller <davem@davemloft.net> Cc: netdev@vger.kernel.org Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> --- net/socket.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/net/socket.c b/net/socket.c
index a05289b1f863..54d19b0edab1 100644
--- a/net/socket.c
+++ b/net/socket.c@@ -2445,9 +2445,9 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, return datagrams; } -SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg, - unsigned int, vlen, unsigned int, flags, - struct timespec __user *, timeout) +static int do_sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, + unsigned int vlen, unsigned int flags, + struct timespec __user *timeout) { int datagrams; struct timespec timeout_sys;
@@ -2470,6 +2470,13 @@ SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg, return datagrams; } +SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg, + unsigned int, vlen, unsigned int, flags, + struct timespec __user *, timeout) +{ + return do_sys_recvmmsg(fd, mmsg, vlen, flags, timeout); +} + #ifdef __ARCH_WANT_SYS_SOCKETCALL /* Argument list sizes for sys_socketcall */ #define AL(x) ((x) * sizeof(unsigned long))
@@ -2582,8 +2589,8 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) err = sys_recvmsg(a0, (struct user_msghdr __user *)a1, a[2]); break; case SYS_RECVMMSG: - err = sys_recvmmsg(a0, (struct mmsghdr __user *)a1, a[2], a[3], - (struct timespec __user *)a[4]); + err = do_sys_recvmmsg(a0, (struct mmsghdr __user *)a1, a[2], + a[3], (struct timespec __user *)a[4]); break; case SYS_ACCEPT4: err = __sys_accept4(a0, (struct sockaddr __user *)a1,
--
2.16.3