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Commit c1d390d8 authored by Xiaotian Feng's avatar Xiaotian Feng Committed by Tejun Heo
Browse files

megaraid: fix BUG_ON() from incorrect use of delayed work 



megaraid use INIT_WORK to declare a hotplug_work, but cast the
hotplug_work from work_struct to delayed_work and
schedule_delayed_work on it.  This is very dangerous, as other part of
delayed_work might be kernel memories allocated by others.

With commit 8852aac2 ("workqueue: mod_delayed_work_on() shouldn't queue
timer on 0 delay"), schedule_delayed_work() will check dwork->timer
before queue_work even when @delay is 0, this causes megaraid code to
hit the BUG_ON() in workqueue code.  Change megaraid code to use
delayed work.

Signed-off-by: default avatarXiaotian Feng <dannyfeng@tencent.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
parent 8852aac2

drivers/scsi/megaraid/megaraid_sas.h

+1 −1
Original line number Diff line number Diff line
@@ -1276,7 +1276,7 @@ struct megasas_evt_detail { 
} __attribute__ ((packed));



struct megasas_aen_event {

	struct work_struct hotplug_work;

	struct delayed_work hotplug_work;

	struct megasas_instance *instance;

};

drivers/scsi/megaraid/megaraid_sas_base.c

+6 −8
Original line number Diff line number Diff line
@@ -2060,9 +2060,9 @@ megasas_service_aen(struct megasas_instance *instance, struct megasas_cmd *cmd) 
		} else {

			ev->instance = instance;

			instance->ev = ev;

			INIT_WORK(&ev->hotplug_work, megasas_aen_polling);

			schedule_delayed_work(

				(struct delayed_work *)&ev->hotplug_work, 0);

			INIT_DELAYED_WORK(&ev->hotplug_work,

					  megasas_aen_polling);

			schedule_delayed_work(&ev->hotplug_work, 0);

		}

	}

}
@@ -4352,8 +4352,7 @@ megasas_suspend(struct pci_dev *pdev, pm_message_t state) 
	/* cancel the delayed work if this work still in queue */

	if (instance->ev != NULL) {

		struct megasas_aen_event *ev = instance->ev;

		cancel_delayed_work_sync(

			(struct delayed_work *)&ev->hotplug_work);

		cancel_delayed_work_sync(&ev->hotplug_work);

		instance->ev = NULL;

	}
@@ -4545,8 +4544,7 @@ static void __devexit megasas_detach_one(struct pci_dev *pdev) 
	/* cancel the delayed work if this work still in queue*/

	if (instance->ev != NULL) {

		struct megasas_aen_event *ev = instance->ev;

		cancel_delayed_work_sync(

			(struct delayed_work *)&ev->hotplug_work);

		cancel_delayed_work_sync(&ev->hotplug_work);

		instance->ev = NULL;

	}
@@ -5190,7 +5188,7 @@ static void 
megasas_aen_polling(struct work_struct *work)

{

	struct megasas_aen_event *ev =

		container_of(work, struct megasas_aen_event, hotplug_work);

		container_of(work, struct megasas_aen_event, hotplug_work.work);

	struct megasas_instance *instance = ev->instance;

	union megasas_evt_class_locale class_locale;

	struct  Scsi_Host *host;