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authorEric W. Biederman <ebiederm@xmission.com>2012-07-26 05:15:35 -0700
committerEric W. Biederman <ebiederm@xmission.com>2012-11-20 04:18:14 -0800
commitb2e0d98705e60e45bbb3c0032c48824ad7ae0704 (patch)
treee187c82e1c3babd34095f2b946614131719bbb03 /kernel/user_namespace.c
parentcde1975bc242f3e1072bde623ef378e547b73f91 (diff)
downloadlinux-b2e0d98705e60e45bbb3c0032c48824ad7ae0704.tar.bz2
userns: Implement unshare of the user namespace
- Add CLONE_THREAD to the unshare flags if CLONE_NEWUSER is selected As changing user namespaces is only valid if all there is only a single thread. - Restore the code to add CLONE_VM if CLONE_THREAD is selected and the code to addCLONE_SIGHAND if CLONE_VM is selected. Making the constraints in the code clear. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel/user_namespace.c')
-rw-r--r--kernel/user_namespace.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index a9460774e77d..ce92f7e6290a 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -82,6 +82,21 @@ int create_user_ns(struct cred *new)
return 0;
}
+int unshare_userns(unsigned long unshare_flags, struct cred **new_cred)
+{
+ struct cred *cred;
+
+ if (!(unshare_flags & CLONE_NEWUSER))
+ return 0;
+
+ cred = prepare_creds();
+ if (!cred)
+ return -ENOMEM;
+
+ *new_cred = cred;
+ return create_user_ns(cred);
+}
+
void free_user_ns(struct kref *kref)
{
struct user_namespace *parent, *ns =