]> git.openfabrics.org - ~shefty/rdma-dev.git/blobdiff - kernel/fork.c
clone(): fix race between copy_process() and de_thread()
[~shefty/rdma-dev.git] / kernel / fork.c
index 144326b7af505a7c6c2c43cf58e481df29d7e1b2..e6c04d462ab250b806cd2e7d76d84fd1729d121e 100644 (file)
@@ -815,11 +815,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
 {
        struct signal_struct *sig;
 
-       if (clone_flags & CLONE_THREAD) {
-               atomic_inc(&current->signal->count);
-               atomic_inc(&current->signal->live);
+       if (clone_flags & CLONE_THREAD)
                return 0;
-       }
 
        sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
        tsk->signal = sig;
@@ -877,16 +874,6 @@ void __cleanup_signal(struct signal_struct *sig)
        kmem_cache_free(signal_cachep, sig);
 }
 
-static void cleanup_signal(struct task_struct *tsk)
-{
-       struct signal_struct *sig = tsk->signal;
-
-       atomic_dec(&sig->live);
-
-       if (atomic_dec_and_test(&sig->count))
-               __cleanup_signal(sig);
-}
-
 static void copy_flags(unsigned long clone_flags, struct task_struct *p)
 {
        unsigned long new_flags = p->flags;
@@ -1239,6 +1226,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
        }
 
        if (clone_flags & CLONE_THREAD) {
+               atomic_inc(&current->signal->count);
+               atomic_inc(&current->signal->live);
                p->group_leader = current->group_leader;
                list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
        }
@@ -1282,7 +1271,8 @@ bad_fork_cleanup_mm:
        if (p->mm)
                mmput(p->mm);
 bad_fork_cleanup_signal:
-       cleanup_signal(p);
+       if (!(clone_flags & CLONE_THREAD))
+               __cleanup_signal(p->signal);
 bad_fork_cleanup_sighand:
        __cleanup_sighand(p->sighand);
 bad_fork_cleanup_fs: