Commit 444f378b authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

This reverts commit 7a238fcb

 in
preparation for a better and simpler fix proposed by Eric Biederman
(and fixed up by Serge Hallyn)
Acked-by: default avatarSerge E. Hallyn <serue@us.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8c8c4baf
...@@ -35,30 +35,22 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig); ...@@ -35,30 +35,22 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig);
int copy_namespaces(int flags, struct task_struct *tsk); int copy_namespaces(int flags, struct task_struct *tsk);
void get_task_namespaces(struct task_struct *tsk); void get_task_namespaces(struct task_struct *tsk);
void free_nsproxy(struct nsproxy *ns); 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); 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)); struct nsproxy *ns = p->nsproxy;
} if (ns) {
task_lock(p);
static inline struct nsproxy *preexit_task_namespaces(struct task_struct *p) p->nsproxy = NULL;
{ task_unlock(p);
return put_nsproxy(p->nsproxy); put_nsproxy(ns);
} }
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);
} }
#endif #endif
...@@ -396,7 +396,7 @@ void daemonize(const char *name, ...) ...@@ -396,7 +396,7 @@ void daemonize(const char *name, ...)
current->fs = fs; current->fs = fs;
atomic_inc(&fs->count); atomic_inc(&fs->count);
put_and_finalize_nsproxy(current->nsproxy); exit_task_namespaces(current);
current->nsproxy = init_task.nsproxy; current->nsproxy = init_task.nsproxy;
get_task_namespaces(current); get_task_namespaces(current);
...@@ -853,7 +853,6 @@ static void exit_notify(struct task_struct *tsk) ...@@ -853,7 +853,6 @@ static void exit_notify(struct task_struct *tsk)
fastcall NORET_TYPE void do_exit(long code) fastcall NORET_TYPE void do_exit(long code)
{ {
struct task_struct *tsk = current; struct task_struct *tsk = current;
struct nsproxy *ns;
int group_dead; int group_dead;
profile_task_exit(tsk); profile_task_exit(tsk);
...@@ -939,9 +938,8 @@ fastcall NORET_TYPE void do_exit(long code) ...@@ -939,9 +938,8 @@ fastcall NORET_TYPE void do_exit(long code)
tsk->exit_code = code; tsk->exit_code = code;
proc_exit_connector(tsk); proc_exit_connector(tsk);
ns = preexit_task_namespaces(tsk);
exit_notify(tsk); exit_notify(tsk);
exit_task_namespaces(tsk, ns); exit_task_namespaces(tsk);
#ifdef CONFIG_NUMA #ifdef CONFIG_NUMA
mpol_free(tsk->mempolicy); mpol_free(tsk->mempolicy);
tsk->mempolicy = NULL; tsk->mempolicy = NULL;
......
...@@ -1265,7 +1265,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, ...@@ -1265,7 +1265,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
return p; return p;
bad_fork_cleanup_namespaces: bad_fork_cleanup_namespaces:
put_and_finalize_nsproxy(p->nsproxy); exit_task_namespaces(p);
bad_fork_cleanup_keys: bad_fork_cleanup_keys:
exit_keys(p); exit_keys(p);
bad_fork_cleanup_mm: bad_fork_cleanup_mm:
...@@ -1711,7 +1711,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) ...@@ -1711,7 +1711,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
} }
if (new_nsproxy) if (new_nsproxy)
put_and_finalize_nsproxy(new_nsproxy); put_nsproxy(new_nsproxy);
bad_unshare_cleanup_ipc: bad_unshare_cleanup_ipc:
if (new_ipc) if (new_ipc)
......
...@@ -117,7 +117,7 @@ int copy_namespaces(int flags, struct task_struct *tsk) ...@@ -117,7 +117,7 @@ int copy_namespaces(int flags, struct task_struct *tsk)
goto out_pid; goto out_pid;
out: out:
put_and_finalize_nsproxy(old_ns); put_nsproxy(old_ns);
return err; return err;
out_pid: out_pid:
...@@ -135,20 +135,6 @@ int copy_namespaces(int flags, struct task_struct *tsk) ...@@ -135,20 +135,6 @@ int copy_namespaces(int flags, struct task_struct *tsk)
goto out; 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) void free_nsproxy(struct nsproxy *ns)
{ {
if (ns->mnt_ns) if (ns->mnt_ns)
......
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