[PATCH 4/5] drm/i915/gvt: Check if cur_pt_type is valid

[Colin Xu]

On 2019-04-08 13:55, Aleksei Gimbitskii wrote:
> Static code analyzer warns that index value for scratch_pt may be equal
> to -1. Index value type is intel_gvt_gtt_type_t, so it may be any number
> at range -1 to 17. Check first if cur_pt_type and cur_pt_type+1 is valid
> values.
>
> This patch fixed the critial issue #422 reported by klocwork.
>
> Signed-off-by: Aleksei Gimbitskii <aleksei.gimbitskii at intel.com>
> Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
> Cc: Zhi Wang <zhi.a.wang at intel.com>
> ---
>   drivers/gpu/drm/i915/gvt/gtt.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
> index 8dcb6223b985..7dc09b389e59 100644
> --- a/drivers/gpu/drm/i915/gvt/gtt.c
> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
> @@ -936,7 +936,14 @@ static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu,
>   
>   	if (e->type != GTT_TYPE_PPGTT_ROOT_L3_ENTRY
>   		&& e->type != GTT_TYPE_PPGTT_ROOT_L4_ENTRY) {
> -		cur_pt_type = get_next_pt_type(e->type) + 1;
> +		cur_pt_type = get_next_pt_type(e->type);
> +
> +		if (!gtt_type_is_pt(cur_pt_type) ||
> +				!gtt_type_is_pt(cur_pt_type + 1))
> +			return -EINVAL;

It's better to leave some dbgmsg for invalid type.

> +
> +		cur_pt_type += 1;
> +
>   		if (ops->get_pfn(e) ==
>   			vgpu->gtt.scratch_pt[cur_pt_type].page_mfn)
>   			return 0;

-- 
Best Regards,
Colin Xu