Revert "[PATCH] namespaces: fix exit race by splitting exit"
This reverts commit 7a238fcba0629b6f2edbcd37458bae56fcf36be5 in
preparation for a better and simpler fix proposed by Eric Biederman
(and fixed up by Serge Hallyn)
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
index 678e1d3..0b9f0dc 100644
--- a/include/linux/nsproxy.h
+++ b/include/linux/nsproxy.h
@@ -35,30 +35,22 @@
int copy_namespaces(int flags, struct task_struct *tsk);
void get_task_namespaces(struct task_struct *tsk);
void free_nsproxy(struct nsproxy *ns);
-struct nsproxy *put_nsproxy(struct nsproxy *ns);
-static inline void finalize_put_nsproxy(struct nsproxy *ns)
+static inline void put_nsproxy(struct nsproxy *ns)
{
- if (ns)
+ if (atomic_dec_and_test(&ns->count)) {
free_nsproxy(ns);
+ }
}
-static inline void put_and_finalize_nsproxy(struct nsproxy *ns)
+static inline void exit_task_namespaces(struct task_struct *p)
{
- finalize_put_nsproxy(put_nsproxy(ns));
-}
-
-static inline struct nsproxy *preexit_task_namespaces(struct task_struct *p)
-{
- return put_nsproxy(p->nsproxy);
-}
-
-static inline void exit_task_namespaces(struct task_struct *p,
- struct nsproxy *ns)
-{
- task_lock(p);
- p->nsproxy = NULL;
- task_unlock(p);
- finalize_put_nsproxy(ns);
+ struct nsproxy *ns = p->nsproxy;
+ if (ns) {
+ task_lock(p);
+ p->nsproxy = NULL;
+ task_unlock(p);
+ put_nsproxy(ns);
+ }
}
#endif
diff --git a/kernel/exit.c b/kernel/exit.c
index a5bf532..3540172 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -396,7 +396,7 @@
current->fs = fs;
atomic_inc(&fs->count);
- put_and_finalize_nsproxy(current->nsproxy);
+ exit_task_namespaces(current);
current->nsproxy = init_task.nsproxy;
get_task_namespaces(current);
@@ -853,7 +853,6 @@
fastcall NORET_TYPE void do_exit(long code)
{
struct task_struct *tsk = current;
- struct nsproxy *ns;
int group_dead;
profile_task_exit(tsk);
@@ -939,9 +938,8 @@
tsk->exit_code = code;
proc_exit_connector(tsk);
- ns = preexit_task_namespaces(tsk);
exit_notify(tsk);
- exit_task_namespaces(tsk, ns);
+ exit_task_namespaces(tsk);
#ifdef CONFIG_NUMA
mpol_free(tsk->mempolicy);
tsk->mempolicy = NULL;
diff --git a/kernel/fork.c b/kernel/fork.c
index 4cf8684..fc723e5 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1265,7 +1265,7 @@
return p;
bad_fork_cleanup_namespaces:
- put_and_finalize_nsproxy(p->nsproxy);
+ exit_task_namespaces(p);
bad_fork_cleanup_keys:
exit_keys(p);
bad_fork_cleanup_mm:
@@ -1711,7 +1711,7 @@
}
if (new_nsproxy)
- put_and_finalize_nsproxy(new_nsproxy);
+ put_nsproxy(new_nsproxy);
bad_unshare_cleanup_ipc:
if (new_ipc)
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 7b05bce..f5b9ee6 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -117,7 +117,7 @@
goto out_pid;
out:
- put_and_finalize_nsproxy(old_ns);
+ put_nsproxy(old_ns);
return err;
out_pid:
@@ -135,20 +135,6 @@
goto out;
}
-struct nsproxy *put_nsproxy(struct nsproxy *ns)
-{
- if (ns) {
- if (atomic_dec_and_test(&ns->count)) {
- if (ns->mnt_ns) {
- put_mnt_ns(ns->mnt_ns);
- ns->mnt_ns = NULL;
- }
- return ns;
- }
- }
- return NULL;
-}
-
void free_nsproxy(struct nsproxy *ns)
{
if (ns->mnt_ns)
