Messages in this thread | | | Subject | Re: [PATCH RESEND v2 2/5] extcon: extcon-max14577: Fix potential work-queue cancellation race | From | Chanwoo Choi <> | Date | Thu, 10 Jun 2021 18:41:19 +0900 |
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On 6/8/21 7:09 PM, Matti Vaittinen wrote: > The extcon IRQ schedules a work item. IRQ is requested using devm while > WQ is cancelld at remove(). This mixing of devm and manual unwinding has > potential case where the WQ has been emptied (.remove() was ran) but > devm unwinding of IRQ was not yet done. It is possible the IRQ is triggered > at this point scheduling new work item to the already flushed queue. > > Use new devm_work_autocancel() to remove the remove() and to kill the bug. > > Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> > Reviewed-by: Hans de Goede <hdegoede@redhat.com> > --- > > Please note that the change is compile-tested only. All proper testing is > highly appreciated. > --- > drivers/extcon/extcon-max14577.c | 16 +++++----------- > 1 file changed, 5 insertions(+), 11 deletions(-) > > diff --git a/drivers/extcon/extcon-max14577.c b/drivers/extcon/extcon-max14577.c > index ace523924e58..5476f48ed74b 100644 > --- a/drivers/extcon/extcon-max14577.c > +++ b/drivers/extcon/extcon-max14577.c > @@ -6,6 +6,7 @@ > // Chanwoo Choi <cw00.choi@samsung.com> > // Krzysztof Kozlowski <krzk@kernel.org> > > +#include <linux/devm-helpers.h> > #include <linux/kernel.h> > #include <linux/module.h> > #include <linux/i2c.h> > @@ -673,7 +674,10 @@ static int max14577_muic_probe(struct platform_device *pdev) > platform_set_drvdata(pdev, info); > mutex_init(&info->mutex); > > - INIT_WORK(&info->irq_work, max14577_muic_irq_work); > + ret = devm_work_autocancel(&pdev->dev, &info->irq_work, > + max14577_muic_irq_work); > + if (ret) > + return ret; > > switch (max14577->dev_type) { > case MAXIM_DEVICE_TYPE_MAX77836: > @@ -766,15 +770,6 @@ static int max14577_muic_probe(struct platform_device *pdev) > return ret; > } > > -static int max14577_muic_remove(struct platform_device *pdev) > -{ > - struct max14577_muic_info *info = platform_get_drvdata(pdev); > - > - cancel_work_sync(&info->irq_work); > - > - return 0; > -} > - > static const struct platform_device_id max14577_muic_id[] = { > { "max14577-muic", MAXIM_DEVICE_TYPE_MAX14577, }, > { "max77836-muic", MAXIM_DEVICE_TYPE_MAX77836, }, > @@ -797,7 +792,6 @@ static struct platform_driver max14577_muic_driver = { > .of_match_table = of_max14577_muic_dt_match, > }, > .probe = max14577_muic_probe, > - .remove = max14577_muic_remove, > .id_table = max14577_muic_id, > }; > >
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
-- Best Regards, Chanwoo Choi Samsung Electronics
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