Re: [PATCH] gpu: host1x: fix uninitialized variable use

Nathan Chancellor
2023-03-08T16:56:46Z

Ping? This warning is now in 6.3-rc1.

On Thu, Feb 23, 2023 at 09:28:28AM -0700, Nathan Chancellor wrote:
> Hi Thierry, Daniel, and David,
>
> On Fri, Jan 27, 2023 at 11:14:00PM +0100, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > The error handling for platform_get_irq() failing no longer
> > works after a recent change, clang now points this out with
> > a warning:
> >
> > drivers/gpu/host1x/dev.c:520:6: error: variable 'syncpt_irq' is uninitialized when used here [-Werror,-Wuninitialized]
> > if (syncpt_irq < 0)
> > ^~~~~~~~~~
> >
> > Fix this by removing the variable and checking the correct
> > error status.
> >
> > Fixes: 625d4ffb438c ("gpu: host1x: Rewrite syncpoint interrupt handling")
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > ---
> > drivers/gpu/host1x/dev.c | 5 ++---
> > 1 file changed, 2 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
> > index 4872d183d860..aae2efeef503 100644
> > --- a/drivers/gpu/host1x/dev.c
> > +++ b/drivers/gpu/host1x/dev.c
> > @@ -487,7 +487,6 @@ static int host1x_get_resets(struct host1x *host)
> > static int host1x_probe(struct platform_device *pdev)
> > {
> > struct host1x *host;
> > - int syncpt_irq;
> > int err;
> >
> > host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
> > @@ -517,8 +516,8 @@ static int host1x_probe(struct platform_device *pdev)
> > }
> >
> > host->syncpt_irq = platform_get_irq(pdev, 0);
> > - if (syncpt_irq < 0)
> > - return syncpt_irq;
> > + if (host->syncpt_irq < 0)
> > + return host->syncpt_irq;
> >
> > mutex_init(&host->devices_lock);
> > INIT_LIST_HEAD(&host->devices);
> > --
> > 2.39.0
> >
>
> Apologies if this has been reported already or has a solution in
> progress but mainline is now broken because this change got separated
> from the change it is fixing:
>
> https://github.com/ClangBuiltLinux/continuous-integration2/actions/runs/4249931209/jobs/7391912774
> https://storage.tuxsuite.com/public/clangbuiltlinux/continuous-integration2/builds/2M7y9HpiXB13qiC2mkHMyeZOcLW/build.log
>
> I see this change sitting in the drm-tegra tree [1], which is getting
> merged into -next, so it is fixed there, which is why we did not notice
> any issues until the drm-next tree was merged into mainline. Can this be
> fast tracked to Linus to unbreak clang builds with -Werror?
>
> [1]: https://gitlab.freedesktop.org/drm/tegra/-/commit/b9930311641cf2ed905a84aabe27e8f3868aee4a