From 4541e80560ca56d63348f40f2e34b044a5eb3dd7 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 13 Mar 2018 19:24:23 +0100 Subject: [PATCH] net: socket: add __sys_accept4() helper; remove in-kernel call to syscall Using the net-internal helper __sys_accept4() allows us to avoid the internal calls to the sys_accept4() 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 Cc: netdev@vger.kernel.org Signed-off-by: Dominik Brodowski --- include/linux/socket.h | 2 ++ net/compat.c | 4 ++-- net/socket.c | 20 +++++++++++++------- 3 files changed, 17 insertions(+), 9 deletions(-) diff --git a/include/linux/socket.h b/include/linux/socket.h index 54b85abc7265..6a9840271676 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -361,5 +361,7 @@ extern int __sys_recvfrom(int fd, void __user *ubuf, size_t size, extern int __sys_sendto(int fd, void __user *buff, size_t len, unsigned int flags, struct sockaddr __user *addr, int addr_len); +extern int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr, + int __user *upeer_addrlen, int flags); #endif /* _LINUX_SOCKET_H */ diff --git a/net/compat.c b/net/compat.c index fc82982d9b84..0ff9f7451b6f 100644 --- a/net/compat.c +++ b/net/compat.c @@ -823,7 +823,7 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args) ret = sys_listen(a0, a1); break; case SYS_ACCEPT: - ret = sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0); + ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0); break; case SYS_GETSOCKNAME: ret = sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2])); @@ -873,7 +873,7 @@ COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args) compat_ptr(a[4])); break; case SYS_ACCEPT4: - ret = sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]); + ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]); break; default: ret = -EINVAL; diff --git a/net/socket.c b/net/socket.c index 3f037a21ba5e..45f6ea0d57a5 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1519,8 +1519,8 @@ SYSCALL_DEFINE2(listen, int, fd, int, backlog) * clean when we restucture accept also. */ -SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr, - int __user *, upeer_addrlen, int, flags) +int __sys_accept4(int fd, struct sockaddr __user *upeer_sockaddr, + int __user *upeer_addrlen, int flags) { struct socket *sock, *newsock; struct file *newfile; @@ -1599,10 +1599,16 @@ out_fd: goto out_put; } +SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr, + int __user *, upeer_addrlen, int, flags) +{ + return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, flags); +} + SYSCALL_DEFINE3(accept, int, fd, struct sockaddr __user *, upeer_sockaddr, int __user *, upeer_addrlen) { - return sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0); + return __sys_accept4(fd, upeer_sockaddr, upeer_addrlen, 0); } /* @@ -2469,8 +2475,8 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) err = sys_listen(a0, a1); break; case SYS_ACCEPT: - err = sys_accept4(a0, (struct sockaddr __user *)a1, - (int __user *)a[2], 0); + err = __sys_accept4(a0, (struct sockaddr __user *)a1, + (int __user *)a[2], 0); break; case SYS_GETSOCKNAME: err = @@ -2525,8 +2531,8 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) (struct timespec __user *)a[4]); break; case SYS_ACCEPT4: - err = sys_accept4(a0, (struct sockaddr __user *)a1, - (int __user *)a[2], a[3]); + err = __sys_accept4(a0, (struct sockaddr __user *)a1, + (int __user *)a[2], a[3]); break; default: err = -EINVAL;