[PATCH] zap_other_threads() needs tasklist_lock held

diff --git a/fs/exec.c b/fs/exec.c
index a63d5c43da1f693dd2b13c8f7299526eddcc75ac..fffe3d0bb1896ebed414aeb445aa10a93a7d0451 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -601,9 +601,12 @@ static inline int de_thread(struct task_struct *tsk)
 
        if (thread_group_empty(current))
                goto no_thread_group;
+
        /*
-        * Kill all other threads in the thread group:
+        * Kill all other threads in the thread group.
+        * We must hold tasklist_lock to call zap_other_threads.
         */
+       read_lock(&tasklist_lock);
        spin_lock_irq(lock);
        if (oldsig->group_exit) {
                /*
@@ -611,6 +614,7 @@ static inline int de_thread(struct task_struct *tsk)
                 * return so that the signal is processed.
                 */
                spin_unlock_irq(lock);
+               read_unlock(&tasklist_lock);
                kmem_cache_free(sighand_cachep, newsighand);
                if (newsig)
                        kmem_cache_free(signal_cachep, newsig);
@@ -618,6 +622,7 @@ static inline int de_thread(struct task_struct *tsk)
        }
        oldsig->group_exit = 1;
        zap_other_threads(current);
+       read_unlock(&tasklist_lock);
 
        /*
         * Account for the thread group leader hanging around: