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author | JANAK DESAI <janak@us.ibm.com> | 2006-02-07 12:59:00 -0800 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-02-07 16:12:34 -0800 |
commit | 741a295130606143edbf9fc740f633dbc1e6225f (patch) | |
tree | 3679047dd44e94ba94ee1487880a94def93a06f9 /fs | |
parent | 99d1419d96d7df9cfa56bc977810be831bd5ef64 (diff) | |
download | linux-stable-741a295130606143edbf9fc740f633dbc1e6225f.tar.gz linux-stable-741a295130606143edbf9fc740f633dbc1e6225f.tar.bz2 linux-stable-741a295130606143edbf9fc740f633dbc1e6225f.zip |
[PATCH] unshare system call -v5: unshare namespace
If the namespace structure is being shared, allocate a new one and copy
information from the current, shared, structure.
Signed-off-by: Janak Desai <janak@us.ibm.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/namespace.c | 56 |
1 files changed, 36 insertions, 20 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index ce97becff461..a2bef5c81033 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1325,27 +1325,17 @@ dput_out: return retval; } -int copy_namespace(int flags, struct task_struct *tsk) +/* + * Allocate a new namespace structure and populate it with contents + * copied from the namespace of the passed in task structure. + */ +struct namespace *dup_namespace(struct task_struct *tsk, struct fs_struct *fs) { struct namespace *namespace = tsk->namespace; struct namespace *new_ns; struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL; - struct fs_struct *fs = tsk->fs; struct vfsmount *p, *q; - if (!namespace) - return 0; - - get_namespace(namespace); - - if (!(flags & CLONE_NEWNS)) - return 0; - - if (!capable(CAP_SYS_ADMIN)) { - put_namespace(namespace); - return -EPERM; - } - new_ns = kmalloc(sizeof(struct namespace), GFP_KERNEL); if (!new_ns) goto out; @@ -1396,8 +1386,6 @@ int copy_namespace(int flags, struct task_struct *tsk) } up_write(&namespace_sem); - tsk->namespace = new_ns; - if (rootmnt) mntput(rootmnt); if (pwdmnt) @@ -1405,12 +1393,40 @@ int copy_namespace(int flags, struct task_struct *tsk) if (altrootmnt) mntput(altrootmnt); - put_namespace(namespace); - return 0; +out: + return new_ns; +} + +int copy_namespace(int flags, struct task_struct *tsk) +{ + struct namespace *namespace = tsk->namespace; + struct namespace *new_ns; + int err = 0; + + if (!namespace) + return 0; + + get_namespace(namespace); + + if (!(flags & CLONE_NEWNS)) + return 0; + + if (!capable(CAP_SYS_ADMIN)) { + err = -EPERM; + goto out; + } + + new_ns = dup_namespace(tsk, tsk->fs); + if (!new_ns) { + err = -ENOMEM; + goto out; + } + + tsk->namespace = new_ns; out: put_namespace(namespace); - return -ENOMEM; + return err; } asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name, |