Revert "[PATCH] namespaces: fix exit race by splitting exit"

This reverts commit 7a238fcba0 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>
This commit is contained in:
Linus Torvalds 2007-01-30 13:35:18 -08:00
parent 8c8c4bafc3
commit 444f378b23
4 changed files with 16 additions and 40 deletions

View file

@ -35,30 +35,22 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig);
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

View file

@ -396,7 +396,7 @@ void daemonize(const char *name, ...)
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 @@ static void exit_notify(struct task_struct *tsk)
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 @@ fastcall NORET_TYPE void do_exit(long code)
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;

View file

@ -1265,7 +1265,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
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 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
}
if (new_nsproxy)
put_and_finalize_nsproxy(new_nsproxy);
put_nsproxy(new_nsproxy);
bad_unshare_cleanup_ipc:
if (new_ipc)

View file

@ -117,7 +117,7 @@ int copy_namespaces(int flags, struct task_struct *tsk)
goto out_pid;
out:
put_and_finalize_nsproxy(old_ns);
put_nsproxy(old_ns);
return err;
out_pid:
@ -135,20 +135,6 @@ out_ns:
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)