[PATCH v2] drm/amdgpu: fix null ptr access

[Quan, Evan]

[AMD Official Use Only]

For the patch with power code change, we usually have the patch title prefixed with "drm/amd/pm".  
With that fixed, the patch is reviewed-by: Evan Quan <evan.quan at amd.com>

> -----Original Message-----
> From: Cui, Flora <Flora.Cui at amd.com>
> Sent: Friday, January 14, 2022 10:54 AM
> To: Quan, Evan <Evan.Quan at amd.com>; amd-gfx at lists.freedesktop.org
> Cc: Cui, Flora <Flora.Cui at amd.com>
> Subject: [PATCH v2] drm/amdgpu: fix null ptr access
> 
> check null ptr first before access its element
> 
> v2: check adev->pm.dpm_enabled early in amdgpu_debugfs_pm_init()
> 
> Signed-off-by: Flora Cui <flora.cui at amd.com>
> ---
>  drivers/gpu/drm/amd/pm/amdgpu_dpm.c | 2 +-
> drivers/gpu/drm/amd/pm/amdgpu_pm.c  | 3 +++
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> index f0daa66f5b3d..5fc33893a68c 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> @@ -463,7 +463,7 @@ int amdgpu_pm_load_smu_firmware(struct
> amdgpu_device *adev, uint32_t *smu_versio
>  	const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
>  	int r = 0;
> 
> -	if (!pp_funcs->load_firmware)
> +	if (!pp_funcs || !pp_funcs->load_firmware)
>  		return 0;
> 
>  	mutex_lock(&adev->pm.mutex);
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> index 1b03ad7a21ad..49a9c6375343 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> @@ -3583,6 +3583,9 @@ void amdgpu_debugfs_pm_init(struct
> amdgpu_device *adev)
>  	struct drm_minor *minor = adev_to_drm(adev)->primary;
>  	struct dentry *root = minor->debugfs_root;
> 
> +	if (!adev->pm.dpm_enabled)
> +		return;
> +
>  	debugfs_create_file("amdgpu_pm_info", 0444, root, adev,
>  			    &amdgpu_debugfs_pm_info_fops);
> 
> --
> 2.25.1