From nobody Sat Sep 26 13:46:58 2026 Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E859E343889 for ; Tue, 1 Sep 2026 00:51:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.71 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788223889; cv=none; b=aNu3rowK99rSB/FBFM6B7T9vV+mGw0ppGFbTncr/2TkIrE64AmDbfOSCNnQuA+yPYWQsFDSbmnaMxDO63AEnpludRtEcI64B55RsMDbCK9yQSTLFp/AWRzRmH/2/I4M/6kj5Logg1qS9WNMyMC57VzTcZXabRPlAjRg6tTNgCbY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788223889; c=relaxed/simple; bh=sEHl7aUf/ZGWx2/WFt+FKTspaVu4Ji64qoYcp+wBjOc=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=M56mIQfdC0F7fGq5p8SOs7iv0dSr8JmBjXONX0otIGL4rP4q2qSZ8q4bdBbWuueAciMHroqweCYKp4zxbYF3rsn6oJBM0OHrVksc+z2uOcKPBKRHMXmBl+fe9Olq33rypKqAKHkR7RCa5YRahE6zxK7IjQszz1vyu4twsBMA9UM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--robbarnes.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=o6IcrkaE; arc=none smtp.client-ip=209.85.216.71 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--robbarnes.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="o6IcrkaE" Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-398d292eac1so4010925a91.1 for ; Mon, 31 Aug 2026 17:51:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788223887; x=1788828687; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=a5KwmvlvBxfFLHfo0JWSgErTakxlty0j7YG0BukEc9w=; b=o6IcrkaEOHDi3dj8v3JJYU3zWXPBuq/0xhyVjVnKGNwhry3lP1yBLOyQNPxRAesG6C 7bauSEj9RrLLYf5VwPv3Jpvs9RVtn3Q6bN0+RrK0XCPlkO/qe3UdlC4KrsgWsmjz2BCT Ak6B4r3AxCej471JtwXrLpw3MfYCk2eLqVi75lY2M7nKln2fd6UmsZXZhG/4JvJN7gRn ruYBqsYOKzR9JYXWctwjq3lgjFIBn5fzTudczRMo5cnWYQLgkbaQgLUrIE0w1v26+/8y fTpzCr26C7Of9ChPP/n3+QHSdpH9OGlfEdNSf4AGhbW57XQKhzuFUljR9zwtSUjkmUqq Myag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788223887; x=1788828687; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=a5KwmvlvBxfFLHfo0JWSgErTakxlty0j7YG0BukEc9w=; b=O4NGyLm3HcAkp4xbY/Fpkwq8RkBda9DG+TbP1ECnzb7po/+GX9EkPeXa614RWqNQPU 99wIi1SFSSQmb+Ixw7tUgVbpWpyquRgEQyJVHHp7QK5KlwL44Q19jdvTaezwG6qq037+ v/hMRSgY49oo0SpvLySduq0o+e7KoXxczyiLvRVIMYcRclNaz+9gD5M0KIxAIyhCH0tC l78Xmjv+ajuVbLxYnOMUXqqft+WxLmnYi8Gw8MhSMZnbCXisqm8ArhUjKtFyQgLZbpyx rIvCnSGXn1haH2VLGY5hGbzoAbSWWKnFftaGnvgOPwefnIOqJg5g37j2VxDf6i59Ef0G uYXw== X-Forwarded-Encrypted: i=1; AKwUvBx5zQb9c21vLRJP+asXpsR/NKs08bM6ghOqByo6QQUvejXGz2emPcODL2S9TqlxwYC3eXn7mZriEUA6uKg=@vger.kernel.org X-Gm-Message-State: AFuF++nZgFV4sRUab6iLiReqqyWkJ02PNbWJ9zqWbexsCM4gpVNion1j ezp3AJFJ1mV6IMmjxrOR81hnzAqnn2DCG/l7msvXoCQ3umYeg3A8kDr7+OSkQTgLCUjZeX6DLcX cWPOUe0WuMPqe9nf8ow== X-Received: from dlae16.prod.google.com ([2002:a05:701b:2310:b0:13b:9a32:b2d]) (user=robbarnes job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:1a85:b0:398:a2ed:7b5c with SMTP id 98e67ed59e1d1-39907f04d76mr4587104a91.24.1788223886704; Mon, 31 Aug 2026 17:51:26 -0700 (PDT) Date: Mon, 31 Aug 2026 18:51:26 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.55.0.966.g6673acef38-goog Message-ID: <20260901005126.3344929-1-robbarnes@google.com> Subject: [PATCH v5] platform/chrome: cros_ec_proto: Fix deferred response From: Rob Barnes To: bleung@chromium.org, tzungbi@kernel.org Cc: tomhughes@chromium.org, chrome-platform@lists.linux.dev, linux-kernel@vger.kernel.org, Rob Barnes Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When cros_ec_wait_until_complete() succeeds after an EC_RES_IN_PROGRESS status, it previously returned the 4-byte transfer size of EC_CMD_GET_COMMS_STATUS. For 0-byte payload commands (such as EC_CMD_FLASH_ERASE), userspace received 4 bytes instead of 0, causing response size validation errors. For commands expecting non-zero response payloads, the kernel exited without issuing EC_CMD_RESEND_RESPONSE, leaving response buffers uninitialized. Refactor cros_ec_wait_until_complete() to pass orig_msg, issue EC_CMD_RESEND_RESPONSE into orig_msg->data when insize > 0, and return 0 for 0-byte response commands. Signed-off-by: Rob Barnes --- v5: - In KUnit tests, set ec_dev->max_response before transfer and drop msg->ou= tsize in payload_4bytes test (Tzung-Bi). v4: - Rebase against upstream chrome-platform/for-next branch (Tzung-Bi). - Send patch using git-send-email via Google Mail Relay to prevent MTA line= -wrapping (Tzung-Bi). v3: - Rebase against upstream chrome-platform tree (Tzung-Bi). v2: - Drop redundant commit description sentences (Tzung-Bi). - Align function signature parameters to open parenthesis (Tzung-Bi). - Check orig_msg->insize =3D=3D 0 and add comments explaining the logic (Tz= ung-Bi / Rob). - Use u32 instead of uint32_t (Tzung-Bi). - Rename 0bytes test to 0byte (Tzung-Bi). - Check header immutability for insize in test cases (Tzung-Bi). --- drivers/platform/chrome/cros_ec_proto.c | 32 +++- drivers/platform/chrome/cros_ec_proto_test.c | 158 ++++++++++++++++++- 2 files changed, 183 insertions(+), 7 deletions(-) diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chr= ome/cros_ec_proto.c index 1d8d9168ec1a..6d7c57e381e5 100644 --- a/drivers/platform/chrome/cros_ec_proto.c +++ b/drivers/platform/chrome/cros_ec_proto.c @@ -138,7 +138,8 @@ static int cros_ec_xfer_command(struct cros_ec_device *= ec_dev, struct cros_ec_co return ret; } =20 -static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint= 32_t *result) +static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, + struct cros_ec_command *orig_msg) { DEFINE_RAW_FLEX(struct cros_ec_command, msg, data, sizeof(struct ec_response_get_comms_status)); @@ -161,7 +162,7 @@ static int cros_ec_wait_until_complete(struct cros_ec_d= evice *ec_dev, uint32_t * if (ret < 0) return ret; =20 - *result =3D msg->result; + orig_msg->result =3D msg->result; if (msg->result !=3D EC_RES_SUCCESS) return ret; =20 @@ -170,8 +171,31 @@ static int cros_ec_wait_until_complete(struct cros_ec_= device *ec_dev, uint32_t * break; } =20 - if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) + if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) { + u32 orig_cmd, orig_outsize, orig_version; + + /* If no response payload is expected, return 0. */ + if (orig_msg->insize =3D=3D 0) + return 0; + + /* + * Request the response using EC_CMD_RESEND_RESPONSE. + * Restore the original message fields so it appears + * to be a direct response to the original command. + */ + orig_cmd =3D orig_msg->command; + orig_outsize =3D orig_msg->outsize; + orig_version =3D orig_msg->version; + + orig_msg->command =3D EC_CMD_RESEND_RESPONSE; + orig_msg->outsize =3D 0; + orig_msg->version =3D 0; + ret =3D cros_ec_xfer_command(ec_dev, orig_msg); + orig_msg->command =3D orig_cmd; + orig_msg->outsize =3D orig_outsize; + orig_msg->version =3D orig_version; return ret; + } } =20 if (i >=3D EC_COMMAND_RETRIES) @@ -185,7 +209,7 @@ static int cros_ec_send_command(struct cros_ec_device *= ec_dev, struct cros_ec_co int ret =3D cros_ec_xfer_command(ec_dev, msg); =20 if (msg->result =3D=3D EC_RES_IN_PROGRESS) - ret =3D cros_ec_wait_until_complete(ec_dev, &msg->result); + ret =3D cros_ec_wait_until_complete(ec_dev, msg); =20 return ret; } diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platfor= m/chrome/cros_ec_proto_test.c index 3f281996a686..cbaaf98d6877 100644 --- a/drivers/platform/chrome/cros_ec_proto_test.c +++ b/drivers/platform/chrome/cros_ec_proto_test.c @@ -1744,7 +1744,7 @@ static void cros_ec_proto_test_cmd_xfer_protocol_v2_n= o_op(struct kunit *test) KUNIT_EXPECT_EQ(test, ret, -EIO); } =20 -static void cros_ec_proto_test_cmd_xfer_in_progress_normal(struct kunit *t= est) +static void cros_ec_proto_test_cmd_xfer_in_progress_payload_0byte(struct k= unit *test) { struct cros_ec_proto_test_priv *priv =3D test->priv; struct cros_ec_device *ec_dev =3D &priv->ec_dev; @@ -1774,7 +1774,7 @@ static void cros_ec_proto_test_cmd_xfer_in_progress_n= ormal(struct kunit *test) } =20 ret =3D cros_ec_cmd_xfer(ec_dev, &msg); - KUNIT_EXPECT_EQ(test, ret, sizeof(struct ec_response_get_comms_status)); + KUNIT_EXPECT_EQ(test, ret, 0); =20 KUNIT_EXPECT_EQ(test, msg.result, EC_RES_SUCCESS); =20 @@ -1799,6 +1799,156 @@ static void cros_ec_proto_test_cmd_xfer_in_progress= _normal(struct kunit *test) KUNIT_EXPECT_EQ(test, cros_kunit_ec_pkt_xfer_mock_called, 2); } =20 +static void cros_ec_proto_test_cmd_xfer_in_progress_payload_4bytes(struct = kunit *test) +{ + struct cros_ec_proto_test_priv *priv =3D test->priv; + struct cros_ec_device *ec_dev =3D &priv->ec_dev; + struct ec_xfer_mock *mock; + u8 resp_data[4] =3D {0x11, 0x22, 0x33, 0x44}; + struct { + struct cros_ec_command msg; + u8 data[4]; + } buf; + struct cros_ec_command *msg =3D &buf.msg; + int ret; + + memset(&buf, 0, sizeof(buf)); + msg->version =3D 1; + msg->command =3D 0x1234; + msg->insize =3D sizeof(buf.data); + + ec_dev->max_response =3D sizeof(buf.data); + ec_dev->pkt_xfer =3D cros_kunit_ec_pkt_xfer_mock; + + /* For initial command returning EC_RES_IN_PROGRESS. */ + { + mock =3D cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_IN_PROGRESS, 0); + KUNIT_ASSERT_PTR_NE(test, mock, NULL); + } + + /* For EC_CMD_GET_COMMS_STATUS status polling. */ + { + struct ec_response_get_comms_status *data; + + mock =3D cros_kunit_ec_xfer_mock_add(test, sizeof(*data)); + KUNIT_ASSERT_PTR_NE(test, mock, NULL); + + data =3D (struct ec_response_get_comms_status *)mock->o_data; + data->flags =3D 0; + } + + /* For EC_CMD_RESEND_RESPONSE returning 4 bytes payload. */ + { + mock =3D cros_kunit_ec_xfer_mock_add(test, sizeof(resp_data)); + KUNIT_ASSERT_PTR_NE(test, mock, NULL); + memcpy(mock->o_data, resp_data, sizeof(resp_data)); + } + + ret =3D cros_ec_cmd_xfer(ec_dev, msg); + KUNIT_EXPECT_EQ(test, ret, 4); + KUNIT_EXPECT_EQ(test, msg->result, EC_RES_SUCCESS); + KUNIT_EXPECT_EQ(test, msg->command, 0x1234); + KUNIT_EXPECT_EQ(test, msg->insize, sizeof(buf.data)); + KUNIT_EXPECT_EQ(test, msg->version, 1); + KUNIT_EXPECT_EQ(test, memcmp(msg->data, resp_data, sizeof(resp_data)), 0); + + /* Verify mock sequence */ + { + mock =3D cros_kunit_ec_xfer_mock_next(); + KUNIT_EXPECT_PTR_NE(test, mock, NULL); + + mock =3D cros_kunit_ec_xfer_mock_next(); + KUNIT_EXPECT_PTR_NE(test, mock, NULL); + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_COMMS_STATUS); + + mock =3D cros_kunit_ec_xfer_mock_next(); + KUNIT_EXPECT_PTR_NE(test, mock, NULL); + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_RESEND_RESPONSE); + KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0); + KUNIT_EXPECT_EQ(test, mock->msg.version, 0); + KUNIT_EXPECT_EQ(test, mock->msg.insize, 4); + } + + KUNIT_EXPECT_EQ(test, cros_kunit_ec_pkt_xfer_mock_called, 3); +} + +static void cros_ec_proto_test_cmd_xfer_in_progress_payload_gt4bytes(struc= t kunit *test) +{ + struct cros_ec_proto_test_priv *priv =3D test->priv; + struct cros_ec_device *ec_dev =3D &priv->ec_dev; + struct ec_xfer_mock *mock; + u8 resp_data[16]; + struct { + struct cros_ec_command msg; + u8 data[16]; + } buf; + struct cros_ec_command *msg =3D &buf.msg; + int ret, i; + + for (i =3D 0; i < sizeof(resp_data); ++i) + resp_data[i] =3D (u8)(i + 1); + + memset(&buf, 0, sizeof(buf)); + msg->version =3D 0; + msg->command =3D 0x5678; + msg->insize =3D sizeof(buf.data); + + ec_dev->max_response =3D sizeof(buf.data); + ec_dev->pkt_xfer =3D cros_kunit_ec_pkt_xfer_mock; + + /* For initial command returning EC_RES_IN_PROGRESS. */ + { + mock =3D cros_kunit_ec_xfer_mock_addx(test, 0, EC_RES_IN_PROGRESS, 0); + KUNIT_ASSERT_PTR_NE(test, mock, NULL); + } + + /* For EC_CMD_GET_COMMS_STATUS status polling. */ + { + struct ec_response_get_comms_status *data; + + mock =3D cros_kunit_ec_xfer_mock_add(test, sizeof(*data)); + KUNIT_ASSERT_PTR_NE(test, mock, NULL); + + data =3D (struct ec_response_get_comms_status *)mock->o_data; + data->flags =3D 0; + } + + /* For EC_CMD_RESEND_RESPONSE returning 16 bytes payload. */ + { + mock =3D cros_kunit_ec_xfer_mock_add(test, sizeof(resp_data)); + KUNIT_ASSERT_PTR_NE(test, mock, NULL); + memcpy(mock->o_data, resp_data, sizeof(resp_data)); + } + + ret =3D cros_ec_cmd_xfer(ec_dev, msg); + KUNIT_EXPECT_EQ(test, ret, 16); + KUNIT_EXPECT_EQ(test, msg->result, EC_RES_SUCCESS); + KUNIT_EXPECT_EQ(test, msg->command, 0x5678); + KUNIT_EXPECT_EQ(test, msg->outsize, 0); + KUNIT_EXPECT_EQ(test, msg->insize, sizeof(buf.data)); + KUNIT_EXPECT_EQ(test, msg->version, 0); + KUNIT_EXPECT_EQ(test, memcmp(msg->data, resp_data, sizeof(resp_data)), 0); + + /* Verify mock sequence */ + { + mock =3D cros_kunit_ec_xfer_mock_next(); + KUNIT_EXPECT_PTR_NE(test, mock, NULL); + + mock =3D cros_kunit_ec_xfer_mock_next(); + KUNIT_EXPECT_PTR_NE(test, mock, NULL); + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_GET_COMMS_STATUS); + + mock =3D cros_kunit_ec_xfer_mock_next(); + KUNIT_EXPECT_PTR_NE(test, mock, NULL); + KUNIT_EXPECT_EQ(test, mock->msg.command, EC_CMD_RESEND_RESPONSE); + KUNIT_EXPECT_EQ(test, mock->msg.outsize, 0); + KUNIT_EXPECT_EQ(test, mock->msg.version, 0); + KUNIT_EXPECT_EQ(test, mock->msg.insize, 16); + } + + KUNIT_EXPECT_EQ(test, cros_kunit_ec_pkt_xfer_mock_called, 3); +} + static void cros_ec_proto_test_cmd_xfer_in_progress_retries_eagain(struct = kunit *test) { struct cros_ec_proto_test_priv *priv =3D test->priv; @@ -2703,7 +2853,9 @@ static struct kunit_case cros_ec_proto_test_cases[] = =3D { KUNIT_CASE(cros_ec_proto_test_cmd_xfer_protocol_v3_no_op), KUNIT_CASE(cros_ec_proto_test_cmd_xfer_protocol_v2_normal), KUNIT_CASE(cros_ec_proto_test_cmd_xfer_protocol_v2_no_op), - KUNIT_CASE(cros_ec_proto_test_cmd_xfer_in_progress_normal), + KUNIT_CASE(cros_ec_proto_test_cmd_xfer_in_progress_payload_0byte), + KUNIT_CASE(cros_ec_proto_test_cmd_xfer_in_progress_payload_4bytes), + KUNIT_CASE(cros_ec_proto_test_cmd_xfer_in_progress_payload_gt4bytes), KUNIT_CASE(cros_ec_proto_test_cmd_xfer_in_progress_retries_eagain), KUNIT_CASE(cros_ec_proto_test_cmd_xfer_in_progress_retries_status_process= ing), KUNIT_CASE(cros_ec_proto_test_cmd_xfer_in_progress_xfer_error), --=20 2.55.0.966.g6673acef38-goog