Re: [PATCH] i915/perf: Fix NULL deref bugs with drm_dbg() calls

[Andrzej Hajda <andrzej.hajda@xxxxxxxxx>]

On 27.10.2023 16:07, Harshit Mogalapalli wrote:
> When i915 perf interface is not available dereferencing it will lead to
> NULL dereferences.
>
> Fix this by using DRM_DEBUG() which the scenario before the commit in
> the Fixes tag.
>
> Fixes: 2fec539112e8 ("i915/perf: Replace DRM_DEBUG with driver specific drm_dbg call")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>


Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>

Regards
Andrzej

> ---
> This is found using smatch(static analysis tool), only compile tested.
> ---
>   drivers/gpu/drm/i915/i915_perf.c | 9 +++------
>   1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
> index 2f3ecd7d4804..bb48c96b7950 100644
> --- a/drivers/gpu/drm/i915/i915_perf.c
> +++ b/drivers/gpu/drm/i915/i915_perf.c
> @@ -4228,8 +4228,7 @@ int i915_perf_open_ioctl(struct drm_device *dev, void *data,
>   	int ret;
>   
>   	if (!perf->i915) {
> -		drm_dbg(&perf->i915->drm,
> -			"i915 perf interface not available for this system\n");
> +		DRM_DEBUG("i915 perf interface not available for this system\n");
>   		return -ENOTSUPP;
>   	}
>   
> @@ -4608,8 +4607,7 @@ int i915_perf_add_config_ioctl(struct drm_device *dev, void *data,
>   	int err, id;
>   
>   	if (!perf->i915) {
> -		drm_dbg(&perf->i915->drm,
> -			"i915 perf interface not available for this system\n");
> +		DRM_DEBUG("i915 perf interface not available for this system\n");
>   		return -ENOTSUPP;
>   	}
>   
> @@ -4774,8 +4772,7 @@ int i915_perf_remove_config_ioctl(struct drm_device *dev, void *data,
>   	int ret;
>   
>   	if (!perf->i915) {
> -		drm_dbg(&perf->i915->drm,
> -			"i915 perf interface not available for this system\n");
> +		DRM_DEBUG("i915 perf interface not available for this system\n");
>   		return -ENOTSUPP;
>   	}
>