EDAC: Robustify workqueues destruction

EDAC workqueue destruction is really fragile. We cancel delayed work but if it is still running and requeues itself, we still go ahead and destroy the workqueue and the queued work explodes when workqueue core attempts to run it. Make the destruction more robust by switching op_state to offline so that requeuing stops. Cancel any pending work *synchronously* too. EDAC i7core: Driver loaded. general protection fault: 0000 [#1] SMP CPU 12 Modules linked in: Supported: Yes Pid: 0, comm: kworker/0:1 Tainted: G IE 3.0.101-0-default #1 HP ProLiant DL380 G7 RIP: 0010:[<ffffffff8107dcd7>] [<ffffffff8107dcd7>] __queue_work+0x17/0x3f0 < ... regs ...> Process kworker/0:1 (pid: 0, threadinfo ffff88019def6000, task ffff88019def4600) Stack: ... Call Trace: call_timer_fn run_timer_softirq __do_softirq call_softirq do_softirq irq_exit smp_apic_timer_interrupt apic_timer_interrupt intel_idle cpuidle_idle_call cpu_idle Code: ... RIP __queue_work RSP <...> Signed-off-by: Borislav Petkov <[email protected]> Cc: <[email protected]>
ambv · Dec 11, 2015 · fcd5c4d · fcd5c4d
1 parent 12e2696
commit fcd5c4d
Show file tree

Hide file tree

Showing 3 changed files with 11 additions and 23 deletions.
diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
@@ -435,16 +435,13 @@ void edac_device_workq_setup(struct edac_device_ctl_info *edac_dev,
  */
 void edac_device_workq_teardown(struct edac_device_ctl_info *edac_dev)
 {
-	int status;
-
 	if (!edac_dev->edac_check)
 		return;
 
-	status = cancel_delayed_work(&edac_dev->work);
-	if (status == 0) {
-		/* workq instance might be running, wait for it */
-		flush_workqueue(edac_workqueue);
-	}
+	edac_dev->op_state = OP_OFFLINE;
+
+	cancel_delayed_work_sync(&edac_dev->work);
+	flush_workqueue(edac_workqueue);
 }
 
 /*

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
@@ -586,18 +586,10 @@ static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec,
  */
 static void edac_mc_workq_teardown(struct mem_ctl_info *mci)
 {
-	int status;
-
-	if (mci->op_state != OP_RUNNING_POLL)
-		return;
-
-	status = cancel_delayed_work(&mci->work);
-	if (status == 0) {
-		edac_dbg(0, "not canceled, flush the queue\n");
+	mci->op_state = OP_OFFLINE;
 
-		/* workq instance might be running, wait for it */
-		flush_workqueue(edac_workqueue);
-	}
+	cancel_delayed_work_sync(&mci->work);
+	flush_workqueue(edac_workqueue);
 }
 
 /*

diff --git a/drivers/edac/edac_pci.c b/drivers/edac/edac_pci.c
@@ -239,13 +239,12 @@ static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
  */
 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 {
-	int status;
-
 	edac_dbg(0, "\n");
 
-	status = cancel_delayed_work(&pci->work);
-	if (status == 0)
-		flush_workqueue(edac_workqueue);
+	pci->op_state = OP_OFFLINE;
+
+	cancel_delayed_work_sync(&pci->work);
+	flush_workqueue(edac_workqueue);
 }
 
 /*