[PATCH] drm/hisilicon: Use pcim_enable_device()

[Daniel Vetter]

On Tue, Dec 22, 2020 at 1:38 AM tiantao (H) <tiantao6 at huawei.com> wrote:
>
>
> 在 2020/12/22 6:02, Daniel Vetter 写道:
> > On Mon, Dec 21, 2020 at 08:45:22AM +0800, Tian Tao wrote:
> >> Using the managed function simplifies the error handling. After
> >> unloading the driver, the PCI device should now get disabled as
> >> well.
> >>
> >> Signed-off-by: Tian Tao <tiantao6 at hisilicon.com>
> >> ---
> >>   drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 6 ++----
> >>   1 file changed, 2 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> >> index 02f3bd1..7159018 100644
> >> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> >> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> >> @@ -329,7 +329,7 @@ static int hibmc_pci_probe(struct pci_dev *pdev,
> >>      dev->pdev = pdev;
> >>      pci_set_drvdata(pdev, dev);
> >>
> >> -    ret = pci_enable_device(pdev);
> >> +    ret = pcim_enable_device(pdev);
> >>      if (ret) {
> >>              drm_err(dev, "failed to enable pci device: %d\n", ret);
> >>              goto err_free;
> >> @@ -338,7 +338,7 @@ static int hibmc_pci_probe(struct pci_dev *pdev,
> >>      ret = hibmc_load(dev);
> >>      if (ret) {
> >>              drm_err(dev, "failed to load hibmc: %d\n", ret);
> >> -            goto err_disable;
> >> +            goto err_free;
> >>      }
> >>
> >>      ret = drm_dev_register(dev, 0);
> >> @@ -354,8 +354,6 @@ static int hibmc_pci_probe(struct pci_dev *pdev,
> >>
> >>   err_unload:
> >>      hibmc_unload(dev);
> >> -err_disable:
> >> -    pci_disable_device(pdev);
> >>   err_free:
> >>      drm_dev_put(dev);
> > The drm_dev_put here and in hibmc_pci_remove is wrong, devm_drm_dev_alloc
> > takes care of that already. I'm kinda suprised you don't have a refcount
> > underrun already - do you test module unload with KASAN enabled?
>
> Thanks for helping to review the code，and kindly giving me advice。
>
> this problem have been fixed。
>
> c855af2f9c5c60760fd1bed7889a81bc37d2591d drm/hisilicon: Fix use-after-free

Sorry, I was on an older tree. Note that this fix is incomplete, the
drm_dev_put in the error path of hibmc_pci_probe still exists.
-Daniel

>
> > The pcim patch looks ok, so Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> >
> > Cheers, Daniel
> >
> >>
> >> --
> >> 2.7.4
> >>
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch