From 1ef6acf597559fd1c244190512144c40619299bf Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Wed, 26 May 2010 23:26:17 +0200 Subject: [PATCH] [S390] cmm: fix crash on module unload There might be a scheduled cmm_timer if the cmm module gets unloaded. That timer was not deleted during module unload and thus could lead to system crash later on. Besides that reorder function calls in module init and exit code to avoid a couple of other races which could lead to accesses to uninitialized data. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/mm/cmm.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c index f87b34731e1d..c17352634a46 100644 --- a/arch/s390/mm/cmm.c +++ b/arch/s390/mm/cmm.c @@ -53,8 +53,8 @@ static struct cmm_page_array *cmm_timed_page_list; static DEFINE_SPINLOCK(cmm_lock); static struct task_struct *cmm_thread_ptr; -static wait_queue_head_t cmm_thread_wait; -static struct timer_list cmm_timer; +static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait); +static DEFINE_TIMER(cmm_timer, NULL, 0, 0); static void cmm_timer_fn(unsigned long); static void cmm_set_timer(void); @@ -466,8 +466,6 @@ cmm_init (void) rc = register_pm_notifier(&cmm_power_notifier); if (rc) goto out_pm; - init_waitqueue_head(&cmm_thread_wait); - init_timer(&cmm_timer); cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0; if (rc) @@ -487,23 +485,25 @@ out_smsg: unregister_sysctl_table(cmm_sysctl_header); out_sysctl: #endif + del_timer_sync(&cmm_timer); return rc; } static void cmm_exit(void) { - kthread_stop(cmm_thread_ptr); - unregister_pm_notifier(&cmm_power_notifier); - unregister_oom_notifier(&cmm_oom_nb); - cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); - cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); #ifdef CONFIG_CMM_PROC unregister_sysctl_table(cmm_sysctl_header); #endif #ifdef CONFIG_CMM_IUCV smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); #endif + unregister_pm_notifier(&cmm_power_notifier); + unregister_oom_notifier(&cmm_oom_nb); + kthread_stop(cmm_thread_ptr); + del_timer_sync(&cmm_timer); + cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); + cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); } module_init(cmm_init); -- 2.39.5