diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-03-16 12:36:06 +0100 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-04-02 20:16:06 +0200 |
| commit | e2aaa9f423367ee03755d632555c242629a08d00 (patch) | |
| tree | c1a4039cf313ab25dcee01b8c90e0fffdd7ff32a | |
| parent | 9b32105ec6b13d32d5db6a6e7992c97ce54b5ea7 (diff) | |
| download | linux-e2aaa9f423367ee03755d632555c242629a08d00.tar.gz linux-e2aaa9f423367ee03755d632555c242629a08d00.tar.bz2 linux-e2aaa9f423367ee03755d632555c242629a08d00.zip | |
kernel: add ksys_setsid() helper; remove in-kernel call to sys_setsid()
Using this helper allows us to avoid the in-kernel call to the
sys_setsid() 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_setsid().
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>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
| -rw-r--r-- | include/linux/syscalls.h | 1 | ||||
| -rw-r--r-- | init/do_mounts_initrd.c | 2 | ||||
| -rw-r--r-- | kernel/sys.c | 7 |
3 files changed, 8 insertions, 2 deletions
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e724dda509e0..4dd685ee425d 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -962,6 +962,7 @@ off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence); ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count); void ksys_sync(void); int ksys_unshare(unsigned long unshare_flags); +int ksys_setsid(void); /* * The following kernel syscall equivalents are just wrappers to fs-internal diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index d1d3e53bdeef..5a91aefa7305 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -45,7 +45,7 @@ static int init_linuxrc(struct subprocess_info *info, struct cred *new) ksys_chdir("/root"); ksys_mount(".", "/", NULL, MS_MOVE, NULL); ksys_chroot("."); - sys_setsid(); + ksys_setsid(); return 0; } diff --git a/kernel/sys.c b/kernel/sys.c index 550f47788ae4..ad692183dfe9 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1150,7 +1150,7 @@ static void set_special_pids(struct pid *pid) change_pid(curr, PIDTYPE_PGID, pid); } -SYSCALL_DEFINE0(setsid) +int ksys_setsid(void) { struct task_struct *group_leader = current->group_leader; struct pid *sid = task_pid(group_leader); @@ -1183,6 +1183,11 @@ out: return err; } +SYSCALL_DEFINE0(setsid) +{ + return ksys_setsid(); +} + DECLARE_RWSEM(uts_sem); #ifdef COMPAT_UTS_MACHINE |