Re: [PATCH] drm/amd/display: Add NULL check for kzalloc in 'amdgpu_dm_atomic_commit_tail()'

["Pillai, Aurabindo" <Aurabindo.Pillai@xxxxxxx>]

[AMD Official Use Only - General]

Prefer drm_err instead of DRM_ERR: https://elixir.bootlin.com/linux/latest/source/include/drm/drm_print.h#L468

With or without that fixed, patch is

Reviewed-by: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>

--

Regards,

Jay

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From: SHANMUGAM, SRINIVASAN <SRINIVASAN.SHANMUGAM@xxxxxxx>
Sent: Tuesday, January 30, 2024 4:45 AM
To: Siqueira, Rodrigo <Rodrigo.Siqueira@xxxxxxx>; Pillai, Aurabindo <Aurabindo.Pillai@xxxxxxx>
Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx <amd-gfx@xxxxxxxxxxxxxxxxxxxxx>; Julia Lawall <julia.lawall@xxxxxxxx>; Hung, Alex <Alex.Hung@xxxxxxx>; Deucher, Alexander <Alexander.Deucher@xxxxxxx>; Chung, ChiaHsuan (Tom) <ChiaHsuan.Chung@xxxxxxx>
Subject: Re: [PATCH] drm/amd/display: Add NULL check for kzalloc in 'amdgpu_dm_atomic_commit_tail()'

 

+ Cc: Tom Chung <chiahsuan.chung@xxxxxxx>

On 1/30/2024 2:11 PM, SHANMUGAM, SRINIVASAN wrote:
> Add a NULL check for the kzalloc call that allocates memory for
> dummy_updates in the amdgpu_dm_atomic_commit_tail function. Previously,
> if kzalloc failed to allocate memory and returned NULL, the code would
> attempt to use the NULL pointer.
>
> The fix is to check if kzalloc returns NULL, and if so, log an error
> message and skip the rest of the current loop iteration with the
> continue statement.  This prevents the code from attempting to use the
> NULL pointer.
>
> Cc: Julia Lawall <julia.lawall@xxxxxxxx>
> Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
> Cc: Rodrigo Siqueira <rodrigo.siqueira@xxxxxxx>
> Cc: Alex Hung <alex.hung@xxxxxxx>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
> ---
>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 0bf1bc7ced7d..8590c9f1dda6 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -9236,6 +9236,10 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
>                 * To fix this, DC should permit updating only stream properties.
>                 */
>                dummy_updates = kzalloc(sizeof(struct dc_surface_update) * MAX_SURFACES, GFP_ATOMIC);
> +             if (!dummy_updates) {
> +                     DRM_ERROR("Failed to allocate memory for dummy_updates.\n");
> +                     continue;
> +             }
>                for (j = 0; j < status->plane_count; j++)
>                        dummy_updates[j].surface = status->plane_states[0];
>