Using this helper allows us to avoid the in-kernel calls to the
sys_unshare() 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_unshare().
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>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
{
char options[] = "mode=0755";
int *err = p;
- *err = sys_unshare(CLONE_NEWNS);
+ *err = ksys_unshare(CLONE_NEWNS);
if (*err)
goto out;
*err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options);
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);
/*
* The following kernel syscall equivalents are just wrappers to fs-internal
static int init_linuxrc(struct subprocess_info *info, struct cred *new)
{
- sys_unshare(CLONE_FS | CLONE_FILES);
+ ksys_unshare(CLONE_FS | CLONE_FILES);
/* stdin/stdout/stderr for /linuxrc */
ksys_open("/dev/console", O_RDWR, 0);
ksys_dup(0);
* constructed. Here we are modifying the current, active,
* task_struct.
*/
-SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
+int ksys_unshare(unsigned long unshare_flags)
{
struct fs_struct *fs, *new_fs = NULL;
struct files_struct *fd, *new_fd = NULL;
return err;
}
+SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
+{
+ return ksys_unshare(unshare_flags);
+}
+
/*
* Helper to unshare the files of the current task.
* We don't want to expose copy_files internals to