From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932887AbeCOTIA (ORCPT ); Thu, 15 Mar 2018 15:08:00 -0400 Received: from isilmar-4.linta.de ([136.243.71.142]:36184 "EHLO isilmar-4.linta.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932674AbeCOTGY (ORCPT ); Thu, 15 Mar 2018 15:06:24 -0400 From: Dominik Brodowski To: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk Cc: luto@kernel.org, mingo@kernel.org, akpm@linux-foundation.org, arnd@arndb.de Subject: [PATCH v2 15/36] fs: add ksys_umount() helper; remove in-kernel call to sys_umount() Date: Thu, 15 Mar 2018 20:05:08 +0100 Message-Id: <20180315190529.20943-16-linux@dominikbrodowski.net> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180315190529.20943-1-linux@dominikbrodowski.net> References: <20180315190529.20943-1-linux@dominikbrodowski.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Using this helper allows us to avoid the in-kernel call to the sys_umount() syscall. Cc: Alexander Viro Signed-off-by: Dominik Brodowski --- fs/namespace.c | 9 +++++++-- include/linux/syscalls.h | 1 + init/do_mounts_initrd.c | 2 +- 3 files changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 642b8b229944..e398f32d7541 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1680,7 +1680,7 @@ static inline bool may_mandlock(void) * unixes. Our API is identical to OSF/1 to avoid making a mess of AMD */ -SYSCALL_DEFINE2(umount, char __user *, name, int, flags) +int ksys_umount(char __user *name, int flags) { struct path path; struct mount *mnt; @@ -1720,6 +1720,11 @@ SYSCALL_DEFINE2(umount, char __user *, name, int, flags) return retval; } +SYSCALL_DEFINE2(umount, char __user *, name, int, flags) +{ + return ksys_umount(name, flags); +} + #ifdef __ARCH_WANT_SYS_OLDUMOUNT /* @@ -1727,7 +1732,7 @@ SYSCALL_DEFINE2(umount, char __user *, name, int, flags) */ SYSCALL_DEFINE1(oldumount, char __user *, name) { - return sys_umount(name, 0); + return ksys_umount(name, 0); } #endif diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 69899ffa03e9..929dfc6c2906 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -950,5 +950,6 @@ asmlinkage long sys_statx(int dfd, const char __user *path, unsigned flags, int ksys_mount(char __user *dev_name, char __user *dir_name, char __user *type, unsigned long flags, void __user *data); +int ksys_umount(char __user *name, int flags); #endif diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index 7868a6039fb4..1c4da8353332 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -105,7 +105,7 @@ static void __init handle_initrd(void) else printk("failed\n"); printk(KERN_NOTICE "Unmounting old root\n"); - sys_umount("/old", MNT_DETACH); + ksys_umount("/old", MNT_DETACH); printk(KERN_NOTICE "Trying to free ramdisk memory ... "); if (fd < 0) { error = fd; -- 2.16.2