powerpc/powernv/idle: Decouple Timebase restore & Per-core SPRs restore

[karo-tx-linux.git] / kernel / fork.c

diff --git a/kernel/fork.c b/kernel/fork.c
index bfd91b180778b1b082014d4bc7e883e4512448bc..e53770d2bf956bf5bf6ec1a42c75121552713da6 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -560,7 +560,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
        set_task_stack_end_magic(tsk);
 
 #ifdef CONFIG_CC_STACKPROTECTOR
-       tsk->stack_canary = get_random_int();
+       tsk->stack_canary = get_random_long();
 #endif
 
        /*
@@ -1577,6 +1577,18 @@ static __latent_entropy struct task_struct *copy_process(
        if (!p)
                goto fork_out;
 
+       /*
+        * This _must_ happen before we call free_task(), i.e. before we jump
+        * to any of the bad_fork_* labels. This is to avoid freeing
+        * p->set_child_tid which is (ab)used as a kthread's data pointer for
+        * kernel threads (PF_KTHREAD).
+        */
+       p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
+       /*
+        * Clear TID on mm_release()?
+        */
+       p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
+
        ftrace_graph_init_task(p);
 
        rt_mutex_init_task(p);
@@ -1743,11 +1755,6 @@ static __latent_entropy struct task_struct *copy_process(
                }
        }
 
-       p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
-       /*
-        * Clear TID on mm_release()?
-        */
-       p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr : NULL;
 #ifdef CONFIG_BLOCK
        p->plug = NULL;
 #endif
@@ -1845,11 +1852,13 @@ static __latent_entropy struct task_struct *copy_process(
        */
        recalc_sigpending();
        if (signal_pending(current)) {
-               spin_unlock(&current->sighand->siglock);
-               write_unlock_irq(&tasklist_lock);
                retval = -ERESTARTNOINTR;
                goto bad_fork_cancel_cgroup;
        }
+       if (unlikely(!(ns_of_pid(pid)->nr_hashed & PIDNS_HASH_ADDING))) {
+               retval = -ENOMEM;
+               goto bad_fork_cancel_cgroup;
+       }
 
        if (likely(p->pid)) {
                ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
@@ -1907,6 +1916,8 @@ static __latent_entropy struct task_struct *copy_process(
        return p;
 
 bad_fork_cancel_cgroup:
+       spin_unlock(&current->sighand->siglock);
+       write_unlock_irq(&tasklist_lock);
        cgroup_cancel_fork(p);
 bad_fork_free_pid:
        cgroup_threadgroup_change_end(current);