[PATCH] drivers/gpu/drm/radeon/radeon_cs.c: eliminate possible double free

[Jerome Glisse]

On Sat, Mar 17, 2012 at 1:03 PM, Julia Lawall <Julia.Lawall at lip6.fr> wrote:
> From: Julia Lawall <Julia.Lawall at lip6.fr>
>
> The function radeon_cs_parser_init is only called from two places, in
> drivers/gpu/drm/radeon/radeon_cs.c and drivers/gpu/drm/radeon/r600_cs.c.
> In each case, if the call fails another function is called that frees all
> of the kdata and dpage information in the chunks array.  So this
> information should not be freed in radeon_cs_parser_init as well.
>
> Signed-off-by: Julia Lawall <Julia.Lawall at lip6.fr>

Reviewed-by: Jerome Glisse <jglisse at redhat.com>
>
> ---
>  drivers/gpu/drm/radeon/radeon_cs.c |   16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
> index 9b4124e..d9d9f5a 100644
> --- a/drivers/gpu/drm/radeon/radeon_cs.c
> +++ b/drivers/gpu/drm/radeon/radeon_cs.c
> @@ -243,20 +243,11 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
>        if ((p->cs_flags & RADEON_CS_USE_VM) &&
>            !p->rdev->vm_manager.enabled) {
>                DRM_ERROR("VM not active on asic!\n");
> -               if (p->chunk_relocs_idx != -1)
> -                       kfree(p->chunks[p->chunk_relocs_idx].kdata);
> -               if (p->chunk_flags_idx != -1)
> -                       kfree(p->chunks[p->chunk_flags_idx].kdata);
>                return -EINVAL;
>        }
>
> -       if (radeon_cs_get_ring(p, ring, priority)) {
> -               if (p->chunk_relocs_idx != -1)
> -                       kfree(p->chunks[p->chunk_relocs_idx].kdata);
> -               if (p->chunk_flags_idx != -1)
> -                       kfree(p->chunks[p->chunk_flags_idx].kdata);
> +       if (radeon_cs_get_ring(p, ring, priority))
>                return -EINVAL;
> -       }
>
>
>        /* deal with non-vm */
> @@ -271,11 +262,8 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
>                p->chunks[p->chunk_ib_idx].kpage[0] = kmalloc(PAGE_SIZE, GFP_KERNEL);
>                p->chunks[p->chunk_ib_idx].kpage[1] = kmalloc(PAGE_SIZE, GFP_KERNEL);
>                if (p->chunks[p->chunk_ib_idx].kpage[0] == NULL ||
> -                   p->chunks[p->chunk_ib_idx].kpage[1] == NULL) {
> -                       kfree(p->chunks[p->chunk_ib_idx].kpage[0]);
> -                       kfree(p->chunks[p->chunk_ib_idx].kpage[1]);
> +                   p->chunks[p->chunk_ib_idx].kpage[1] == NULL)
>                        return -ENOMEM;
> -               }
>                p->chunks[p->chunk_ib_idx].kpage_idx[0] = -1;
>                p->chunks[p->chunk_ib_idx].kpage_idx[1] = -1;
>                p->chunks[p->chunk_ib_idx].last_copied_page = -1;
>
> --
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