Hi, On Mon 22 Aug 22, 22:57, Samuel Holland wrote: > On 8/20/22 3:25 AM, Jernej Škrabec wrote: > > Dne petek, 19. avgust 2022 ob 17:37:20 CEST je Nicolas Dufresne napisal(a): > >> Le vendredi 19 août 2022 à 06:17 +0200, Jernej Škrabec a écrit : > >>> Dne četrtek, 18. avgust 2022 ob 22:33:07 CEST je Nicolas Dufresne > > napisal(a): > >>>> From: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> > >>>> > >>>> The cedrus_hw_resume() crashes with NULL deference on driver probe if > >>>> runtime PM is disabled because it uses platform data that hasn't been > >>>> set up yet. Fix this by setting the platform data earlier during probe. > >>> > >>> Does it even work without PM? Maybe it would be better if Cedrus would > >>> select PM in Kconfig. > >> > >> I cannot comment myself on this, but it does not seem to invalidate this > >> Dmitry's fix. > > > > If NULL pointer dereference happens only when PM is disabled, then it does. I > > have PM always enabled and I never experienced above issue. > > There's still a bug even with PM enabled: the v4l2 device is exposed to > userspace, and therefore userspace could trigger a PM resume, before > platform_set_drvdata() is called. Absolutely agreed! > >>>> Cc: stable@xxxxxxxxxxxxxxx > >>>> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> > >>>> Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx> > > Please add a Fixes tag. With that: > > Reviewed-by: Samuel Holland <samuel@xxxxxxxxxxxx> Same here: Acked-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> Thanks! Paul > >>>> --- > >>>> > >>>> drivers/staging/media/sunxi/cedrus/cedrus.c | 4 ++-- > >>>> 1 file changed, 2 insertions(+), 2 deletions(-) > >>>> > >>>> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c > >>>> b/drivers/staging/media/sunxi/cedrus/cedrus.c index > >>>> 960a0130cd620..55c54dfdc585c 100644 > >>>> --- a/drivers/staging/media/sunxi/cedrus/cedrus.c > >>>> +++ b/drivers/staging/media/sunxi/cedrus/cedrus.c > >>>> @@ -448,6 +448,8 @@ static int cedrus_probe(struct platform_device > >>>> *pdev) > >>>> > >>>> if (!dev) > >>>> return -ENOMEM; > >>>> > >>>> + platform_set_drvdata(pdev, dev); > >>>> + > >>>> dev->vfd = cedrus_video_device; > >>>> dev->dev = &pdev->dev; > >>>> dev->pdev = pdev; > >>>> > >>>> @@ -521,8 +523,6 @@ static int cedrus_probe(struct platform_device > >>>> *pdev) > >>>> > >>>> goto err_m2m_mc; > >>>> } > >>>> > >>>> - platform_set_drvdata(pdev, dev); > >>>> - > >>>> return 0; > >>>> > >>>> err_m2m_mc: -- Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com
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