| Message ID | 20171214054150.20943-1-architt@codeaurora.org (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | Andy Gross |
| Headers | show |
On Thu, Dec 14, 2017 at 11:11:50AM +0530, Archit Taneja wrote: > The msm/kms driver should work even if there is no GPU device specified > in DT. Currently, we get a NULL dereference crash in adreno_load_gpu > since the driver assumes that priv->gpu_pdev is non-NULL. > > Perform an additional check on priv->gpu_pdev before trying to retrieve > the msm_gpu pointer from it. > > Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time) > > Signed-off-by: Archit Taneja <architt@codeaurora.org> > --- > drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c > index 05022ea2a007..ac60cf3c794e 100644 > --- a/drivers/gpu/drm/msm/adreno/adreno_device.c > +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c > @@ -124,10 +124,17 @@ const struct adreno_info *adreno_info(struct adreno_rev rev) > struct msm_gpu *adreno_load_gpu(struct drm_device *dev) > { > struct msm_drm_private *priv = dev->dev_private; > - struct platform_device *pdev = priv->gpu_pdev; > - struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev); > + struct platform_device *pdev; > + struct msm_gpu *gpu; > int ret; > > + pdev = priv->gpu_pdev; > + if (!pdev) { > + dev_dbg(dev->dev, "no adreno platform device found\n"); > + return NULL; > + } > + > + gpu = platform_get_drvdata(pdev); > if (!gpu) { > dev_err(dev->dev, "no adreno device\n"); > return NULL; Obviously correct fix but I can't help but think that we should share the same error message, so something like: struct msm_gpu *gpu = NULL; .. if (priv->gpu_pdev) gpu = platform_get_drvdata(priv->gpu_pdev); if (!gpu) { dev_err(dev->dev, "No GPU device was was found\n"); return NULL; } (also, I can't help but think maybe that dev_err should be a ONCE so you don't get a nasty message every time you open the file descriptor). Jordan
On 12/15/2017 09:03 PM, Jordan Crouse wrote: > On Thu, Dec 14, 2017 at 11:11:50AM +0530, Archit Taneja wrote: >> The msm/kms driver should work even if there is no GPU device specified >> in DT. Currently, we get a NULL dereference crash in adreno_load_gpu >> since the driver assumes that priv->gpu_pdev is non-NULL. >> >> Perform an additional check on priv->gpu_pdev before trying to retrieve >> the msm_gpu pointer from it. >> >> Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time) >> >> Signed-off-by: Archit Taneja <architt@codeaurora.org> >> --- >> drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +++++++++-- >> 1 file changed, 9 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c >> index 05022ea2a007..ac60cf3c794e 100644 >> --- a/drivers/gpu/drm/msm/adreno/adreno_device.c >> +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c >> @@ -124,10 +124,17 @@ const struct adreno_info *adreno_info(struct adreno_rev rev) >> struct msm_gpu *adreno_load_gpu(struct drm_device *dev) >> { >> struct msm_drm_private *priv = dev->dev_private; >> - struct platform_device *pdev = priv->gpu_pdev; >> - struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev); >> + struct platform_device *pdev; >> + struct msm_gpu *gpu; >> int ret; >> >> + pdev = priv->gpu_pdev; >> + if (!pdev) { >> + dev_dbg(dev->dev, "no adreno platform device found\n"); >> + return NULL; >> + } >> + >> + gpu = platform_get_drvdata(pdev); >> if (!gpu) { >> dev_err(dev->dev, "no adreno device\n"); >> return NULL; > > Obviously correct fix but I can't help but think that we should share the same > error message, so something like: > > struct msm_gpu *gpu = NULL; > > .. > > if (priv->gpu_pdev) > gpu = platform_get_drvdata(priv->gpu_pdev); > > if (!gpu) { > dev_err(dev->dev, "No GPU device was was found\n"); > return NULL; > } > > (also, I can't help but think maybe that dev_err should be a ONCE so you don't > get a nasty message every time you open the file descriptor). This approach looks better. I'll re-spin. Thanks, Archit > > Jordan >
diff --git a/drivers/gpu/drm/msm/adreno/adreno_device.c b/drivers/gpu/drm/msm/adreno/adreno_device.c index 05022ea2a007..ac60cf3c794e 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_device.c +++ b/drivers/gpu/drm/msm/adreno/adreno_device.c @@ -124,10 +124,17 @@ const struct adreno_info *adreno_info(struct adreno_rev rev) struct msm_gpu *adreno_load_gpu(struct drm_device *dev) { struct msm_drm_private *priv = dev->dev_private; - struct platform_device *pdev = priv->gpu_pdev; - struct msm_gpu *gpu = platform_get_drvdata(priv->gpu_pdev); + struct platform_device *pdev; + struct msm_gpu *gpu; int ret; + pdev = priv->gpu_pdev; + if (!pdev) { + dev_dbg(dev->dev, "no adreno platform device found\n"); + return NULL; + } + + gpu = platform_get_drvdata(pdev); if (!gpu) { dev_err(dev->dev, "no adreno device\n"); return NULL;
The msm/kms driver should work even if there is no GPU device specified in DT. Currently, we get a NULL dereference crash in adreno_load_gpu since the driver assumes that priv->gpu_pdev is non-NULL. Perform an additional check on priv->gpu_pdev before trying to retrieve the msm_gpu pointer from it. Fixes: eec874ce5ff1 (drm/msm/adreno: load gpu at probe/bind time) Signed-off-by: Archit Taneja <architt@codeaurora.org> --- drivers/gpu/drm/msm/adreno/adreno_device.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)