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References: <20220608110734.2928245-1-tzungbi@kernel.org> <20220608110734.2928245-24-tzungbi@kernel.org>
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From:   Guenter Roeck <groeck@google.com>
Date:   Wed, 8 Jun 2022 09:30:19 -0700
Message-ID: <CABXOdTfLVq30r0+E9GaThXaJgSVjYg6AMP4JfxoiVZ64bdT+Bw@mail.gmail.com>
Subject: Re: [PATCH v3 23/23] platform/chrome: cros_ec_proto: handle empty
 payload in getting wake mask
To:     Tzung-Bi Shih <tzungbi@kernel.org>
Cc:     Benson Leung <bleung@chromium.org>,
        Guenter Roeck <groeck@chromium.org>,
        "open list:CHROME HARDWARE PLATFORM SUPPORT" 
        <chrome-platform@lists.linux.dev>,
        linux-kernel <linux-kernel@vger.kernel.org>
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On Wed, Jun 8, 2022 at 4:08 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> cros_ec_get_host_event_wake_mask() expects to receive
> sizeof(struct ec_response_host_event_mask) from send_command().  The
> payload is valid only if the return value is positive.
>
> Return -EPROTO if send_command() returns 0 in
> cros_ec_get_host_event_wake_mask().
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Reviewed-by: Guenter Roeck <groeck@chromium.org>

> ---
> No v2.  New and separated from the original series.
>
>  drivers/platform/chrome/cros_ec_proto.c | 24 ++++++++++++++----------
>  1 file changed, 14 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 68a411e84744..5cbaaba26ff7 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -256,19 +256,23 @@ static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev, uint3
>         msg->insize = sizeof(*r);
>
>         ret = send_command(ec_dev, msg);
> -       if (ret >= 0) {
> -               mapped = cros_ec_map_error(msg->result);
> -               if (mapped) {
> -                       ret = mapped;
> -                       goto exit;
> -               }
> +       if (ret < 0)
> +               goto exit;
> +
> +       mapped = cros_ec_map_error(msg->result);
> +       if (mapped) {
> +               ret = mapped;
> +               goto exit;
>         }
> -       if (ret > 0) {
> -               r = (struct ec_response_host_event_mask *)msg->data;
> -               *mask = r->mask;
> -               ret = 0;
> +
> +       if (ret == 0) {
> +               ret = -EPROTO;
> +               goto exit;
>         }
>
> +       r = (struct ec_response_host_event_mask *)msg->data;
> +       *mask = r->mask;
> +       ret = 0;
>  exit:
>         kfree(msg);
>         return ret;
> --
> 2.36.1.255.ge46751e96f-goog
>