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References: <20240117071328.3811480-1-alexious@zju.edu.cn>
In-Reply-To: <20240117071328.3811480-1-alexious@zju.edu.cn>
From: Qiang Yu <yuq825@gmail.com>
Date: Wed, 17 Jan 2024 20:14:08 +0800
Message-ID: <CAKGbVbuEyKaeZbvU-SREQkto5AqdQo-wjx=cjf2Sx3eDCnah+Q@mail.gmail.com>
Subject: Re: [PATCH] [v2] drm/lima: fix a memleak in lima_heap_alloc
To: Zhipeng Lu <alexious@zju.edu.cn>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>, Maxime Ripard <mripard@kernel.org>, 
	Thomas Zimmermann <tzimmermann@suse.de>, David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>, 
	Vasily Khoruzhick <anarsoul@gmail.com>, dri-devel@lists.freedesktop.org, 
	lima@lists.freedesktop.org, linux-kernel@vger.kernel.org
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Reviewed-by: Qiang Yu <yuq825@gmail.com>

On Wed, Jan 17, 2024 at 3:14=E2=80=AFPM Zhipeng Lu <alexious@zju.edu.cn> wr=
ote:
>
> When lima_vm_map_bo fails, the resources need to be deallocated, or
> there will be memleaks.
>
> Fixes: 6aebc51d7aef ("drm/lima: support heap buffer creation")
> Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
> ---
> Changelog:
>
> v2: rearrange the error-handling to ladder tags.
> ---
>  drivers/gpu/drm/lima/lima_gem.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_=
gem.c
> index 4f9736e5f929..d3d82ee7fb4c 100644
> --- a/drivers/gpu/drm/lima/lima_gem.c
> +++ b/drivers/gpu/drm/lima/lima_gem.c
> @@ -75,29 +75,36 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_v=
m *vm)
>         } else {
>                 bo->base.sgt =3D kmalloc(sizeof(*bo->base.sgt), GFP_KERNE=
L);
>                 if (!bo->base.sgt) {
> -                       sg_free_table(&sgt);
> -                       return -ENOMEM;
> +                       ret =3D -ENOMEM;
> +                       goto err_out0;
>                 }
>         }
>
>         ret =3D dma_map_sgtable(dev, &sgt, DMA_BIDIRECTIONAL, 0);
>         if (ret) {
> -               sg_free_table(&sgt);
> -               kfree(bo->base.sgt);
> -               bo->base.sgt =3D NULL;
> -               return ret;
> +               goto err_out1;
>         }
>
>         *bo->base.sgt =3D sgt;
>
>         if (vm) {
>                 ret =3D lima_vm_map_bo(vm, bo, old_size >> PAGE_SHIFT);
> -               if (ret)
> -                       return ret;
> +               if (ret) {
> +                       goto err_out2;
> +               }
>         }
>
>         bo->heap_size =3D new_size;
>         return 0;
> +
> +err_out2:
> +       dma_unmap_sgtable(dev, &sgt, DMA_BIDIRECTIONAL, 0);
> +err_out1:
> +       kfree(bo->base.sgt);
> +       bo->base.sgt =3D NULL;
> +err_out0:
> +       sg_free_table(&sgt);
> +       return ret;
>  }
>
>  int lima_gem_create_handle(struct drm_device *dev, struct drm_file *file=
,
> --
> 2.34.1
>