Re: [PATCH 09/11] usb: xhci-mtk: check boundary before check tt
From: Ikjoon Jang
Date: Mon Aug 09 2021 - 03:32:48 EST
Hi Chunfeng,
On Fri, Jul 30, 2021 at 4:50 PM Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> wrote:
>
> check_sch_tt() will access fs_bus_bw[] array, check boundary
> firstly to avoid out-of-bounds issue.
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> ---
> drivers/usb/host/xhci-mtk-sch.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
> index 10c0f0f6461f..c2f13d69c607 100644
> --- a/drivers/usb/host/xhci-mtk-sch.c
> +++ b/drivers/usb/host/xhci-mtk-sch.c
> @@ -600,13 +600,14 @@ static int check_sch_bw(struct mu3h_sch_bw_info *sch_bw,
> * and find a microframe where its worst bandwidth is minimum.
> */
> for (offset = 0; offset < sch_ep->esit; offset++) {
> - ret = check_sch_tt(sch_ep, offset);
> - if (ret)
> - continue;
>
> if ((offset + sch_ep->num_budget_microframes) > esit_boundary)
> break;
Instead of dropping it,
I'm wondering if it should be checked against (offset & 63) == 0 when it's 64?
>
> + ret = check_sch_tt(sch_ep, offset);
> + if (ret)
> + continue;
> +
> worst_bw = get_max_bw(sch_bw, sch_ep, offset);
> if (worst_bw > bw_boundary)
> continue;
> --
> 2.18.0
>