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| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-03-11 11:34:50 +0100 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-04-02 20:15:56 +0200 |
| commit | 87c4e19262d81862886207be3c8795f6576d5a52 (patch) | |
| tree | 29593184be7a8e70b091108ec8299b4436462f23 /fs | |
| parent | b724e846b491ef8db943be8086226c9d8da31877 (diff) | |
| download | lwn-87c4e19262d81862886207be3c8795f6576d5a52.tar.gz lwn-87c4e19262d81862886207be3c8795f6576d5a52.zip | |
fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_mknodat() helper allows us to get rid of
fs-internal calls to the sys_mknodat() syscall.
Introducing the ksys_mknod() wrapper allows us to avoid the in-kernel
calls to sys_mknod() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_mknod().
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: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/internal.h | 2 | ||||
| -rw-r--r-- | fs/namei.c | 12 |
2 files changed, 11 insertions, 3 deletions
diff --git a/fs/internal.h b/fs/internal.h index a3f04ca2a08b..4f0b67054c54 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -55,6 +55,8 @@ extern void __init chrdev_init(void); extern int user_path_mountpoint_at(int, const char __user *, unsigned int, struct path *); extern int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *, unsigned int, struct path *); +long do_mknodat(int dfd, const char __user *filename, umode_t mode, + unsigned int dev); long do_mkdirat(int dfd, const char __user *pathname, umode_t mode); long do_rmdir(int dfd, const char __user *pathname); long do_unlinkat(int dfd, struct filename *name); diff --git a/fs/namei.c b/fs/namei.c index e15da92209d5..8459a18cdd18 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3728,8 +3728,8 @@ static int may_mknod(umode_t mode) } } -SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, - unsigned, dev) +long do_mknodat(int dfd, const char __user *filename, umode_t mode, + unsigned int dev) { struct dentry *dentry; struct path path; @@ -3772,9 +3772,15 @@ out: return error; } +SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, + unsigned int, dev) +{ + return do_mknodat(dfd, filename, mode, dev); +} + SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, dev) { - return sys_mknodat(AT_FDCWD, filename, mode, dev); + return do_mknodat(AT_FDCWD, filename, mode, dev); } int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |