Re: [PATCH] staging: android/lowmemorykiller: Don't grab tasklist_lock

On 02/01, Anton Vorontsov wrote:

@@ -132,7 +133,7 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc) } selected_oom_adj = min_adj;

• read_lock(&tasklist_lock);

• rcu_read_lock();

This has the same problem, force_sig() becomes unsafe.

Why do you need force_? Do you really want to kill /sbin/init (or sub-namespace init) ?

We could change force_sig_info() to use lock_task_sighand(), but I'd like to avoid this. Imho, this interface should be cleanuped, and it should be used for synchronous signals only.

With or without this patch, sig == NULL is not possible but !mm is not right, there could be other other threads with mm != NULL.

Oleg.