This is a note to let you know that I've just added the patch titled EDAC: Robustify workqueues destruction to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: edac-robustify-workqueues-destruction.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fcd5c4dd8201595d4c598c9cca5e54760277d687 Mon Sep 17 00:00:00 2001 From: Borislav Petkov <bp@xxxxxxx> Date: Fri, 27 Nov 2015 10:38:38 +0100 Subject: EDAC: Robustify workqueues destruction From: Borislav Petkov <bp@xxxxxxx> commit fcd5c4dd8201595d4c598c9cca5e54760277d687 upstream. 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 <bp@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/edac/edac_device.c | 11 ++++------- drivers/edac/edac_mc.c | 14 +++----------- drivers/edac/edac_pci.c | 9 ++++----- 3 files changed, 11 insertions(+), 23 deletions(-) --- a/drivers/edac/edac_device.c +++ b/drivers/edac/edac_device.c @@ -435,16 +435,13 @@ void edac_device_workq_setup(struct edac */ 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); } /* --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -586,18 +586,10 @@ static void edac_mc_workq_setup(struct m */ static void edac_mc_workq_teardown(struct mem_ctl_info *mci) { - int status; + mci->op_state = OP_OFFLINE; - 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"); - - /* workq instance might be running, wait for it */ - flush_workqueue(edac_workqueue); - } + cancel_delayed_work_sync(&mci->work); + flush_workqueue(edac_workqueue); } /* --- a/drivers/edac/edac_pci.c +++ b/drivers/edac/edac_pci.c @@ -274,13 +274,12 @@ static void edac_pci_workq_setup(struct */ 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); } /* Patches currently in stable-queue which might be from bp@xxxxxxx are queue-4.4/edac-robustify-workqueues-destruction.patch queue-4.4/edac-mc_sysfs-fix-freeing-bus-name.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html