From 5e787dbf659fe77d56215be74044f85e01b3920f Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 23 Oct 2018 22:10:35 +0200 Subject: devtmpfs: use do_mount() instead of ksys_mount() In devtmpfs, do_mount() can be called directly instead of complex wrapping by ksys_mount(): - the first and third arguments are const strings in the kernel, and do not need to be copied over from userspace; - the fifth argument is NULL, and therefore no page needs to be copied over from userspace; - the second and fourth argument are passed through anyway. Signed-off-by: Dominik Brodowski --- include/linux/device.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/device.h b/include/linux/device.h index e226030c1df3..96ff76731e93 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1666,11 +1666,11 @@ extern bool kill_device(struct device *dev); #ifdef CONFIG_DEVTMPFS extern int devtmpfs_create_node(struct device *dev); extern int devtmpfs_delete_node(struct device *dev); -extern int devtmpfs_mount(const char *mntdir); +extern int devtmpfs_mount(void); #else static inline int devtmpfs_create_node(struct device *dev) { return 0; } static inline int devtmpfs_delete_node(struct device *dev) { return 0; } -static inline int devtmpfs_mount(const char *mountpoint) { return 0; } +static inline int devtmpfs_mount(void) { return 0; } #endif /* drivers/base/power/shutdown.c */ -- cgit v1.2.3 From cccaa5e33525fc07f4a2ce0518e50b9ddf435e47 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 23 Oct 2018 22:41:09 +0200 Subject: init: use do_mount() instead of ksys_mount() In prepare_namespace(), do_mount() can be used instead of ksys_mount() as the first and third argument are const strings in the kernel, the second and fourth argument are passed through anyway, and the fifth argument is NULL. In do_mount_root(), ksys_mount() is called with the first and third argument being already kernelspace strings, which do not need to be copied over from userspace to kernelspace (again). The second and fourth arguments are passed through to do_mount() anyway. The fifth argument, while already residing in kernelspace, needs to be put into a page of its own. Then, do_mount() can be used instead of ksys_mount(). Once this is done, there are no in-kernel users to ksys_mount() left, which can therefore be removed. Signed-off-by: Dominik Brodowski --- include/linux/syscalls.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index d0391cc2dae9..5262b7a76d39 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1231,8 +1231,6 @@ asmlinkage long sys_ni_syscall(void); * the ksys_xyzyyz() functions prototyped below. */ -int ksys_mount(const char __user *dev_name, const char __user *dir_name, - const char __user *type, unsigned long flags, void __user *data); int ksys_umount(char __user *name, int flags); int ksys_dup(unsigned int fildes); int ksys_chroot(const char __user *filename); -- cgit v1.2.3 From b49a733d684e0096340b93e9dfd471f0e3ddc06d Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 23 Oct 2018 16:00:10 +0200 Subject: init: unify opening /dev/console as stdin/stdout/stderr Merge the two instances where /dev/console is opened as stdin/stdout/stderr. Signed-off-by: Dominik Brodowski --- include/linux/initrd.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/initrd.h b/include/linux/initrd.h index d77fe34fb00a..aa5914355728 100644 --- a/include/linux/initrd.h +++ b/include/linux/initrd.h @@ -28,3 +28,5 @@ extern unsigned int real_root_dev; extern char __initramfs_start[]; extern unsigned long __initramfs_size; + +void console_on_rootfs(void); -- cgit v1.2.3 From 8243186f0cc7c57cf9d6a110cd7315c44e3e0be8 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Tue, 23 Oct 2018 16:24:09 +0200 Subject: fs: remove ksys_dup() ksys_dup() is used only at one place in the kernel, namely to duplicate fd 0 of /dev/console to stdout and stderr. The same functionality can be achieved by using functions already available within the kernel namespace. Signed-off-by: Dominik Brodowski --- include/linux/syscalls.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 5262b7a76d39..2960dedcfde8 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -1232,7 +1232,6 @@ asmlinkage long sys_ni_syscall(void); */ int ksys_umount(char __user *name, int flags); -int ksys_dup(unsigned int fildes); int ksys_chroot(const char __user *filename); ssize_t ksys_write(unsigned int fd, const char __user *buf, size_t count); int ksys_chdir(const char __user *filename); -- cgit v1.2.3