From 00b0a66a031ee7024cd0aa7e69a26c6731d1b0fe Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Thu, 9 Sep 2010 10:48:21 +0530 Subject: [PATCH] lowmemorykiller: don't unregister notifier from atomic context The lowmemorykiller registers an atomic notifier for notfication of when the task is freed. From this atomic notifier callback, it removes the atomic notifier via task_free_unregister(). This is incorrect because atomic_notifier_chain_unregister() calls syncronize_rcu(), which can sleep, which shouldn't be done from an atomic notifier. Fix this by registering the notifier during init, and only unregister it if the lowmemorykiller is unloaded. Change-Id: I1577b04e617bc2b2e39dcb490fcfc9ce660eb7ec Signed-off-by: Rabin Vincent Signed-off-by: Christian Bejram --- drivers/staging/android/lowmemorykiller.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index 8b67ac06e4b0..efbe556ba862 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -71,10 +71,10 @@ static int task_notify_func(struct notifier_block *self, unsigned long val, void *data) { struct task_struct *task = data; - if (task == lowmem_deathpending) { + + if (task == lowmem_deathpending) lowmem_deathpending = NULL; - task_free_unregister(&task_nb); - } + return NOTIFY_OK; } @@ -168,7 +168,6 @@ static int lowmem_shrink(struct shrinker *s, int nr_to_scan, gfp_t gfp_mask) selected->pid, selected->comm, selected_oom_adj, selected_tasksize); lowmem_deathpending = selected; - task_free_register(&task_nb); force_sig(SIGKILL, selected); rem -= selected_tasksize; } @@ -185,6 +184,7 @@ static struct shrinker lowmem_shrinker = { static int __init lowmem_init(void) { + task_free_register(&task_nb); register_shrinker(&lowmem_shrinker); return 0; } @@ -192,6 +192,7 @@ static int __init lowmem_init(void) static void __exit lowmem_exit(void) { unregister_shrinker(&lowmem_shrinker); + task_free_unregister(&task_nb); } module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR); -- 2.34.1