Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
MIME-Version: 1.0
References: <20220607145639.2362750-1-tzungbi@kernel.org> <20220607145639.2362750-9-tzungbi@kernel.org>
In-Reply-To: <20220607145639.2362750-9-tzungbi@kernel.org>
From:   Guenter Roeck <groeck@google.com>
Date:   Tue, 7 Jun 2022 11:47:56 -0700
Message-ID: <CABXOdTdx7jKLbHa3X7aOz3wUMpwWWHkncfKuRyGzonkA92Rg=w@mail.gmail.com>
Subject: Re: [PATCH v2 08/15] platform/chrome: cros_ec_proto: handle empty
 payload in getting proto info
To:     Tzung-Bi Shih <tzungbi@kernel.org>
Cc:     bleung@chromium.org, groeck@chromium.org,
        chrome-platform@lists.linux.dev, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Tue, Jun 7, 2022 at 7:57 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> cros_ec_get_proto_info() expects to receive
> sizeof(struct ec_response_get_protocol_info) from send_command().  The
> payload is valid only if the return value is positive.
>
> Add Kunit tests for returning 0 in send_command() and handle the case in
> cros_ec_get_proto_info().
>
That should be two separate patches.

> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
> ---
> No v1.  New in the series.
>
>  drivers/platform/chrome/cros_ec_proto.c      |   5 +
>  drivers/platform/chrome/cros_ec_proto_test.c | 132 +++++++++++++++++++
>  2 files changed, 137 insertions(+)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 893b76703da6..6f5be9e5ede4 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -314,6 +314,11 @@ static int cros_ec_get_proto_info(struct cros_ec_device *ec_dev, int devidx)
>                 goto exit;
>         }
>
> +       if (ret == 0) {
> +               ret = -EPROTO;
> +               goto exit;
> +       }
> +

I think you can move that into the if() statement above (which already
checks for ret >=0),
making it a special case of that situation.

Thanks,
Guenter

>         info = (struct ec_response_get_protocol_info *)msg->data;
>
>         switch (devidx) {
> diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
> index 14a4441a39fc..473714964cf2 100644
> --- a/drivers/platform/chrome/cros_ec_proto_test.c
> +++ b/drivers/platform/chrome/cros_ec_proto_test.c
> @@ -406,6 +406,71 @@ static void cros_ec_proto_test_query_all_no_pd_return_error(struct kunit *test)
>         }
>  }
>
> +static void cros_ec_proto_test_query_all_no_pd_return0(struct kunit *test)
> +{
> +       struct cros_ec_proto_test_priv *priv = test->priv;
> +       struct cros_ec_device *ec_dev = &priv->ec_dev;
> +       struct ec_xfer_mock *mock;
> +       int ret;
> +
> +       /* Set some garbage bytes. */
> +       ec_dev->max_passthru = 0xbf;
> +
> +       /* For cros_ec_get_proto_info() without passthru. */
> +       {
> +               struct ec_response_get_protocol_info *data;
> +
> +               mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
> +               KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> +
> +               /*
> +                * Although it doesn't check the value, provides valid sizes so that
> +                * cros_ec_query_all() allocates din and dout correctly.
> +                */
> +               data = (struct ec_response_get_protocol_info *)mock->o_data;
> +               data->max_request_packet_size = 0xbe;
> +               data->max_response_packet_size = 0xef;
> +       }
> +
> +       /* For cros_ec_get_proto_info() with passthru. */
> +       {
> +               mock = cros_kunit_ec_xfer_mock_add(test, 0);
> +               KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> +       }
> +
> +       cros_ec_proto_test_query_all_pretest(test);
> +       ret = cros_ec_query_all(ec_dev);
> +       KUNIT_EXPECT_EQ(test, ret, 0);
> +
> +       /* For cros_ec_get_proto_info() without passthru. */
> +       {
> +               mock = cros_kunit_ec_xfer_mock_next();
> +               KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> +               KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> +               KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_PROTOCOL_INFO);
> +               KUNIT_EXPECT_EQ(test, mock->msg.insize,
> +                               sizeof(struct ec_response_get_protocol_info));
> +               KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
> +       }
> +
> +       /* For cros_ec_get_proto_info() with passthru. */
> +       {
> +               mock = cros_kunit_ec_xfer_mock_next();
> +               KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> +               KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> +               KUNIT_EXPECT_EQ(test, mock->msg.command,
> +                               EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX) |
> +                               EC_CMD_GET_PROTOCOL_INFO);
> +               KUNIT_EXPECT_EQ(test, mock->msg.insize,
> +                               sizeof(struct ec_response_get_protocol_info));
> +               KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
> +
> +               KUNIT_EXPECT_EQ(test, ec_dev->max_passthru, 0);
> +       }
> +}
> +
>  static void cros_ec_proto_test_query_all_legacy_normal_v3_return_error(struct kunit *test)
>  {
>         struct cros_ec_proto_test_priv *priv = test->priv;
> @@ -471,6 +536,71 @@ static void cros_ec_proto_test_query_all_legacy_normal_v3_return_error(struct ku
>         }
>  }
>
> +static void cros_ec_proto_test_query_all_legacy_normal_v3_return0(struct kunit *test)
> +{
> +       struct cros_ec_proto_test_priv *priv = test->priv;
> +       struct cros_ec_device *ec_dev = &priv->ec_dev;
> +       struct ec_xfer_mock *mock;
> +       int ret;
> +
> +       /* For cros_ec_get_proto_info() without passthru. */
> +       {
> +               mock = cros_kunit_ec_xfer_mock_add(test, 0);
> +               KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> +       }
> +
> +       /* For cros_ec_host_command_proto_query_v2(). */
> +       {
> +               struct ec_response_hello *data;
> +
> +               mock = cros_kunit_ec_xfer_mock_add(test, sizeof(*data));
> +               KUNIT_ASSERT_PTR_NE(test, mock, NULL);
> +
> +               data = (struct ec_response_hello *)mock->o_data;
> +               data->out_data = 0xa1b2c3d4;
> +       }
> +
> +       cros_ec_proto_test_query_all_pretest(test);
> +       ret = cros_ec_query_all(ec_dev);
> +       KUNIT_EXPECT_EQ(test, ret, 0);
> +
> +       /* For cros_ec_get_proto_info() without passthru. */
> +       {
> +               mock = cros_kunit_ec_xfer_mock_next();
> +               KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> +               KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> +               KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_PROTOCOL_INFO);
> +               KUNIT_EXPECT_EQ(test, mock->msg.insize,
> +                               sizeof(struct ec_response_get_protocol_info));
> +               KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0);
> +       }
> +
> +       /* For cros_ec_host_command_proto_query_v2(). */
> +       {
> +               struct ec_params_hello *data;
> +
> +               mock = cros_kunit_ec_xfer_mock_next();
> +               KUNIT_EXPECT_PTR_NE(test, mock, NULL);
> +
> +               KUNIT_EXPECT_EQ(test, mock->msg.version, 0);
> +               KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_HELLO);
> +               KUNIT_EXPECT_EQ(test, mock->msg.insize, sizeof(struct ec_response_hello));
> +               KUNIT_EXPECT_EQ(test, mock->msg.outsize, sizeof(*data));
> +
> +               data = (struct ec_params_hello *)mock->i_data;
> +               KUNIT_EXPECT_EQ(test, data->in_data, 0xa0b0c0d0);
> +
> +               KUNIT_EXPECT_EQ(test, ec_dev->proto_version, 2);
> +               KUNIT_EXPECT_EQ(test, ec_dev->max_request, EC_PROTO2_MAX_PARAM_SIZE);
> +               KUNIT_EXPECT_EQ(test, ec_dev->max_response, EC_PROTO2_MAX_PARAM_SIZE);
> +               KUNIT_EXPECT_EQ(test, ec_dev->max_passthru, 0);
> +               KUNIT_EXPECT_PTR_EQ(test, ec_dev->pkt_xfer, NULL);
> +               KUNIT_EXPECT_EQ(test, ec_dev->din_size, EC_PROTO2_MSG_BYTES);
> +               KUNIT_EXPECT_EQ(test, ec_dev->dout_size, EC_PROTO2_MSG_BYTES);
> +       }
> +}
> +
>  static void cros_ec_proto_test_query_all_legacy_xfer_error(struct kunit *test)
>  {
>         struct cros_ec_proto_test_priv *priv = test->priv;
> @@ -998,7 +1128,9 @@ static struct kunit_case cros_ec_proto_test_cases[] = {
>         KUNIT_CASE(cros_ec_proto_test_check_result),
>         KUNIT_CASE(cros_ec_proto_test_query_all_normal),
>         KUNIT_CASE(cros_ec_proto_test_query_all_no_pd_return_error),
> +       KUNIT_CASE(cros_ec_proto_test_query_all_no_pd_return0),
>         KUNIT_CASE(cros_ec_proto_test_query_all_legacy_normal_v3_return_error),
> +       KUNIT_CASE(cros_ec_proto_test_query_all_legacy_normal_v3_return0),
>         KUNIT_CASE(cros_ec_proto_test_query_all_legacy_xfer_error),
>         KUNIT_CASE(cros_ec_proto_test_query_all_legacy_return_error),
>         KUNIT_CASE(cros_ec_proto_test_query_all_legacy_data_error),
> --
> 2.36.1.255.ge46751e96f-goog
>