From patchwork Thu Mar 29 11:22:45 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dominik Brodowski X-Patchwork-Id: 892767 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=dominikbrodowski.net Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40BjsJ1fVVz9s0m for ; Thu, 29 Mar 2018 22:56:52 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753125AbeC2L4u (ORCPT ); Thu, 29 Mar 2018 07:56:50 -0400 Received: from isilmar-4.linta.de ([136.243.71.142]:59398 "EHLO isilmar-4.linta.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752653AbeC2L0F (ORCPT ); Thu, 29 Mar 2018 07:26:05 -0400 Received: from light.dominikbrodowski.net (isilmar.linta [10.0.0.1]) by isilmar-4.linta.de (Postfix) with ESMTPS id D73A5200911; Thu, 29 Mar 2018 11:26:00 +0000 (UTC) Received: by light.dominikbrodowski.net (Postfix, from userid 1000) id 062BA20849; Thu, 29 Mar 2018 13:24:37 +0200 (CEST) From: Dominik Brodowski To: linux-kernel@vger.kernel.org Cc: viro@ZenIV.linux.org.uk, torvalds@linux-foundation.org, arnd@arndb.de, linux-arch@vger.kernel.org, "David S . Miller" , netdev@vger.kernel.org Subject: [PATCH 008/109] net: socket: add __sys_recvfrom() helper; remove in-kernel call to syscall Date: Thu, 29 Mar 2018 13:22:45 +0200 Message-Id: <20180329112426.23043-9-linux@dominikbrodowski.net> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180329112426.23043-1-linux@dominikbrodowski.net> References: <20180329112426.23043-1-linux@dominikbrodowski.net> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Using the net-internal helper __sys_recvfrom() allows us to avoid the internal calls to the sys_recvfrom() 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 | 6 ++++++ net/compat.c | 3 ++- net/socket.c | 21 +++++++++++++-------- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/include/linux/socket.h b/include/linux/socket.h index 9286a5a8c60c..40cc93b91628 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -353,4 +353,10 @@ extern int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen unsigned int flags, struct timespec *timeout); extern int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, unsigned int flags); + +/* helpers which do the actual work for syscalls */ +extern int __sys_recvfrom(int fd, void __user *ubuf, size_t size, + unsigned int flags, struct sockaddr __user *addr, + int __user *addr_len); + #endif /* _LINUX_SOCKET_H */ diff --git a/net/compat.c b/net/compat.c index 22381719718c..2d8186c277b2 100644 --- a/net/compat.c +++ b/net/compat.c @@ -760,7 +760,8 @@ COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len unsigned int, flags, struct sockaddr __user *, addr, int __user *, addrlen) { - return sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr, addrlen); + return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr, + addrlen); } COMPAT_SYSCALL_DEFINE5(recvmmsg, int, fd, struct compat_mmsghdr __user *, mmsg, diff --git a/net/socket.c b/net/socket.c index a93c99b518ca..712d99d8680f 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1767,10 +1767,8 @@ SYSCALL_DEFINE4(send, int, fd, void __user *, buff, size_t, len, * sender. We verify the buffers are writable and if needed move the * sender address from kernel to user space. */ - -SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size, - unsigned int, flags, struct sockaddr __user *, addr, - int __user *, addr_len) +int __sys_recvfrom(int fd, void __user *ubuf, size_t size, unsigned int flags, + struct sockaddr __user *addr, int __user *addr_len) { struct socket *sock; struct iovec iov; @@ -1810,6 +1808,13 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size, return err; } +SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size, + unsigned int, flags, struct sockaddr __user *, addr, + int __user *, addr_len) +{ + return __sys_recvfrom(fd, ubuf, size, flags, addr, addr_len); +} + /* * Receive a datagram from a socket. */ @@ -1817,7 +1822,7 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size, SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size, unsigned int, flags) { - return sys_recvfrom(fd, ubuf, size, flags, NULL, NULL); + return __sys_recvfrom(fd, ubuf, size, flags, NULL, NULL); } /* @@ -2486,9 +2491,9 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) err = sys_recv(a0, (void __user *)a1, a[2], a[3]); break; case SYS_RECVFROM: - err = sys_recvfrom(a0, (void __user *)a1, a[2], a[3], - (struct sockaddr __user *)a[4], - (int __user *)a[5]); + err = __sys_recvfrom(a0, (void __user *)a1, a[2], a[3], + (struct sockaddr __user *)a[4], + (int __user *)a[5]); break; case SYS_SHUTDOWN: err = sys_shutdown(a0, a1);