From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> Currently in c67x00_drv_probe() IRQ is requested before calling c67x00_probe_sie() and hence if interrupt happens the reading of certain variables in the handler can race with initialization of the variables, for e.g. sie->sie_num is written in c67x00_probe_sie() and read in c67x00_hcd_irq(). Hence, this patch calls c67x00_probe_sie() before requesting IRQ in probe. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> --- drivers/usb/c67x00/c67x00-drv.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/c67x00/c67x00-drv.c b/drivers/usb/c67x00/c67x00-drv.c index 53838e7d4eef..2e816d5ca0eb 100644 --- a/drivers/usb/c67x00/c67x00-drv.c +++ b/drivers/usb/c67x00/c67x00-drv.c @@ -146,6 +146,9 @@ static int c67x00_drv_probe(struct platform_device *pdev) c67x00_ll_init(c67x00); c67x00_ll_hpi_reg_init(c67x00); + for (i = 0; i < C67X00_SIES; i++) + c67x00_probe_sie(&c67x00->sie[i], c67x00, i); + ret = request_irq(res2->start, c67x00_irq, 0, pdev->name, c67x00); if (ret) { dev_err(&pdev->dev, "Cannot claim IRQ\n"); @@ -158,9 +161,6 @@ static int c67x00_drv_probe(struct platform_device *pdev) goto reset_failed; } - for (i = 0; i < C67X00_SIES; i++) - c67x00_probe_sie(&c67x00->sie[i], c67x00, i); - platform_set_drvdata(pdev, c67x00); return 0; -- 2.17.1
On Wed, Aug 26, 2020 at 08:14:59PM +0530, madhuparnabhowmik10@gmail.com wrote:
> From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>
> Currently in c67x00_drv_probe() IRQ is requested before calling
> c67x00_probe_sie() and hence if interrupt happens the reading of certain
> variables in the handler can race with initialization of the variables,
> for e.g. sie->sie_num is written in c67x00_probe_sie() and read in
> c67x00_hcd_irq().
> Hence, this patch calls c67x00_probe_sie() before requesting IRQ in
> probe.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
> ---
> drivers/usb/c67x00/c67x00-drv.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/c67x00/c67x00-drv.c b/drivers/usb/c67x00/c67x00-drv.c
> index 53838e7d4eef..2e816d5ca0eb 100644
> --- a/drivers/usb/c67x00/c67x00-drv.c
> +++ b/drivers/usb/c67x00/c67x00-drv.c
> @@ -146,6 +146,9 @@ static int c67x00_drv_probe(struct platform_device *pdev)
> c67x00_ll_init(c67x00);
> c67x00_ll_hpi_reg_init(c67x00);
>
> + for (i = 0; i < C67X00_SIES; i++)
> + c67x00_probe_sie(&c67x00->sie[i], c67x00, i);
> +
> ret = request_irq(res2->start, c67x00_irq, 0, pdev->name, c67x00);
> if (ret) {
> dev_err(&pdev->dev, "Cannot claim IRQ\n");
> @@ -158,9 +161,6 @@ static int c67x00_drv_probe(struct platform_device *pdev)
> goto reset_failed;
> }
>
> - for (i = 0; i < C67X00_SIES; i++)
> - c67x00_probe_sie(&c67x00->sie[i], c67x00, i);
> -
> platform_set_drvdata(pdev, c67x00);
>
> return 0;
Have you tested this on hardware to verify it works properly?
thanks,
greg k-h
On Fri, Aug 28, 2020 at 1:10 PM Greg KH <gregkh@linuxfoundation.org> wrote: > > On Wed, Aug 26, 2020 at 08:14:59PM +0530, madhuparnabhowmik10@gmail.com wrote: > > From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> > > > > Currently in c67x00_drv_probe() IRQ is requested before calling > > c67x00_probe_sie() and hence if interrupt happens the reading of certain > > variables in the handler can race with initialization of the variables, > > for e.g. sie->sie_num is written in c67x00_probe_sie() and read in > > c67x00_hcd_irq(). > > Hence, this patch calls c67x00_probe_sie() before requesting IRQ in > > probe. > > > > Found by Linux Driver Verification project (linuxtesting.org). > > > > Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com> > > --- > > drivers/usb/c67x00/c67x00-drv.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/usb/c67x00/c67x00-drv.c b/drivers/usb/c67x00/c67x00-drv.c > > index 53838e7d4eef..2e816d5ca0eb 100644 > > --- a/drivers/usb/c67x00/c67x00-drv.c > > +++ b/drivers/usb/c67x00/c67x00-drv.c > > @@ -146,6 +146,9 @@ static int c67x00_drv_probe(struct platform_device *pdev) > > c67x00_ll_init(c67x00); > > c67x00_ll_hpi_reg_init(c67x00); > > > > + for (i = 0; i < C67X00_SIES; i++) > > + c67x00_probe_sie(&c67x00->sie[i], c67x00, i); > > + > > ret = request_irq(res2->start, c67x00_irq, 0, pdev->name, c67x00); > > if (ret) { > > dev_err(&pdev->dev, "Cannot claim IRQ\n"); > > @@ -158,9 +161,6 @@ static int c67x00_drv_probe(struct platform_device *pdev) > > goto reset_failed; > > } > > > > - for (i = 0; i < C67X00_SIES; i++) > > - c67x00_probe_sie(&c67x00->sie[i], c67x00, i); > > - > > platform_set_drvdata(pdev, c67x00); > > > > return 0; > > Have you tested this on hardware to verify it works properly? No, I haven't, don't think I have the relevant hardware. It would be great if someone could test this and add a Tested-by tag. Thanks, Madhuparna > > thanks, > > greg k-h