Re: [PATCH] exit.c: Fix Sparse errors and warnings

From: Oleg Nesterov
Date: Wed Jan 29 2020 - 07:31:02 EST


On 01/28, madhuparnabhowmik10@xxxxxxxxx wrote:
>
> kernel/exit.c:626:40: warning: incorrect type in assignment
>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
> ---
> kernel/exit.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/exit.c b/kernel/exit.c
> index bcbd59888e67..c5a9d6360440 100644
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -623,8 +623,8 @@ static void forget_original_parent(struct task_struct *father,
> reaper = find_new_reaper(father, reaper);
> list_for_each_entry(p, &father->children, sibling) {
> for_each_thread(p, t) {
> - t->real_parent = reaper;
> - BUG_ON((!t->ptrace) != (t->parent == father));
> + rcu_assign_pointer(t->real_parent, reaper);

Another case when RCU_INIT_POINTER() makes more sense (although to me it
too looks confusing). We didn't modify the new parent.

Oleg.