lkml.org 
[lkml]   [2022]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] drm/msm/mdp5: check the return of kzalloc()
On Thu, Mar 24, 2022 at 1:37 AM <xkernel.wang@foxmail.com> wrote:
>
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
>
> kzalloc() is a memory allocation function which can return NULL when
> some internal memory errors happen. So it is better to check it to
> prevent potential wrong memory access.
>
> Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
> ---
> drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
> index c6b69af..5f914cc 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
> @@ -90,15 +90,18 @@ static void mdp5_plane_reset(struct drm_plane *plane)
> __drm_atomic_helper_plane_destroy_state(plane->state);
>
> kfree(to_mdp5_plane_state(plane->state));
> - mdp5_state = kzalloc(sizeof(*mdp5_state), GFP_KERNEL);
> + plane->state = NULL;

At this point, you could just:

if (!mdp5_state)
return;

BR,
-R

>
> - if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> - mdp5_state->base.zpos = STAGE_BASE;
> - else
> - mdp5_state->base.zpos = STAGE0 + drm_plane_index(plane);
> - mdp5_state->base.normalized_zpos = mdp5_state->base.zpos;
> + mdp5_state = kzalloc(sizeof(*mdp5_state), GFP_KERNEL);
> + if (mdp5_state) {
> + if (plane->type == DRM_PLANE_TYPE_PRIMARY)
> + mdp5_state->base.zpos = STAGE_BASE;
> + else
> + mdp5_state->base.zpos = STAGE0 + drm_plane_index(plane);
> + mdp5_state->base.normalized_zpos = mdp5_state->base.zpos;
>
> - __drm_atomic_helper_plane_reset(plane, &mdp5_state->base);
> + __drm_atomic_helper_plane_reset(plane, &mdp5_state->base);
> + }
> }
>
> static struct drm_plane_state *
> --

\
 
 \ /
  Last update: 2022-04-06 19:48    [W:0.059 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site