Re: [PATCH drm-dp 03/10] drm/hisilicon/hibmc: fix irq_request()'s irq name variable is local

[Dmitry Baryshkov]

On 09/06/2025 17:50, Yongbang Shi wrote:
> > On Fri, May 30, 2025 at 05:54:25PM +0800, Yongbang Shi wrote:
> > > From: Baihan Li <libaihan@xxxxxxxxxx>
> > >
> > > The local variable of irq name is passed to devm_request_threaded_irq(),
> > > which will make request_irq failed. Using the global irq name instead
> > > of it to fix.
> > This doesn't explain, why does it fail and which IRQ name is actually
> > expected.
>
> The local variable is passed in request_irq (), and there will be use 
> after free problem.

This needs to be explained (in details) in the commit message.

> > > Fixes: b11bc1ae4658 ("drm/hisilicon/hibmc: Add MSI irq getting and 
> > > requesting for HPD")
> > > Signed-off-by: Baihan Li <libaihan@xxxxxxxxxx>
> > > ---
> > >   drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 10 +++-------
> > >   1 file changed, 3 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/ 
> > > drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > > index 768b97f9e74a..4cdcc34070ee 100644
> > > --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > > +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > > @@ -32,7 +32,7 @@
> > >   DEFINE_DRM_GEM_FOPS(hibmc_fops);
> > > -static const char *g_irqs_names_map[HIBMC_MAX_VECTORS] = { "vblank", 
> > > "hpd" };
> > > +static const char *g_irqs_names_map[HIBMC_MAX_VECTORS] = { "hibmc- 
> > > vblank", "hibmc-hpd" };
> > Please point to the corresponding IRQ names as currently implemented in
> > the upstream kernel.
>
> Ok.

I was thinking in terms of IRQ lookup. You can ignore this comment (it 
makes me wonder, how did you understand it, if you responded with Ok).

> > >   static irqreturn_t hibmc_interrupt(int irq, void *arg)
> > >   {


--
With best wishes
Dmitry