[PATCH] drm/msm/dpu: Add callback function pointer check before its call

[Dmitry Baryshkov]

On Wed, 10 Apr 2024 at 14:53, Aleksandr Mishin <amishin at t-argos.ru> wrote:
> On 08.04.2024 12:03, Dmitry Baryshkov wrote:
> > On Mon, 8 Apr 2024 at 11:57, Aleksandr Mishin <amishin at t-argos.ru> wrote:
> >>
> >> In dpu_core_irq_callback_handler() callback function pointer is compared to NULL,
> >> but then callback function is unconditionally called by this pointer.
> >> Fix this bug by adding conditional return.
> >>
> >> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> >
> > This should be converted to a proper Reported-by: trailer.
> >
>
> It is an established practice for our project, you can find 700+ applied
> patches with similar line:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=linuxtesting.org

Is there any reason why your project doesn't follow established
guidelines? Compare this to other robots.

Anyway:

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>

>
> >>
> >> Fixes: c929ac60b3ed ("drm/msm/dpu: allow just single IRQ callback")
> >> Signed-off-by: Aleksandr Mishin <amishin at t-argos.ru>
> >> ---
> >>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c | 4 +++-
> >>   1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> >> index 946dd0135dff..03a16fbd4c99 100644
> >> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> >> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> >> @@ -223,9 +223,11 @@ static void dpu_core_irq_callback_handler(struct dpu_kms *dpu_kms, unsigned int
> >>
> >>          VERB("IRQ=[%d, %d]\n", DPU_IRQ_REG(irq_idx), DPU_IRQ_BIT(irq_idx));
> >>
> >> -       if (!irq_entry->cb)
> >> +       if (!irq_entry->cb) {
> >>                  DRM_ERROR("no registered cb, IRQ=[%d, %d]\n",
> >>                            DPU_IRQ_REG(irq_idx), DPU_IRQ_BIT(irq_idx));
> >> +               return;
> >> +       }
> >>
> >>          atomic_inc(&irq_entry->count);
> >>
> >> --
> >> 2.30.2
> >>
> >>
> >
> >
>
> --
> Kind regards
> Aleksandr



-- 
With best wishes
Dmitry