From nobody Tue Sep 29 07:44:25 2026 Received: from mail-yw1-f174.google.com (mail-yw1-f174.google.com [209.85.128.174]) (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 8456130DEB0 for ; Mon, 10 Aug 2026 21:43:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=209.85.128.174 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786398214; cv=pass; b=di3k7u9KMu3//rkY+nAtiJ8UBvN9zoMEoTT89e8hIFOyjm9iZqh4OQmAsMLbwEeg/V70bp4iS5u8ppWG745JnrXk/GEd4CEkFJwYFQoIIUbAobNvk+H0ZbLw7UO1babJoQ5BVlR/jBXHBjRqJE5kVpcMOKiZZ5aPnHXxWQtPEGM= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786398214; c=relaxed/simple; bh=iqjKdojbjbodxxgb+n9rGN+o3qDP32daF85ZK8aHiuc=; h=MIME-Version:From:Date:Message-ID:Subject:To:Cc:Content-Type; b=H7ZhcA7M5wSdFAkOApT/vY915YGhPezgvUR9mn7AgAeL/RUyGj0ynYWxgiGIARU3JZkAGoX3Kufa7IdNXPGIqiv3cNnxOvvEtXObAQcTZQHBr/PdC0UClMVdwErVkeGxVAKEvjhmfwtjd62wD07Y8xZzhNzCpOoUm5oWWWilN98= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Kbwz0MBB; arc=pass smtp.client-ip=209.85.128.174 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=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Kbwz0MBB" Received: by mail-yw1-f174.google.com with SMTP id 00721157ae682-82011c59e66so3811037b3.0 for ; Mon, 10 Aug 2026 14:43:32 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1786398211; cv=none; d=google.com; s=arc-20260327; b=V6Y8moqE94DFMDQMUpwMGagBVkWdG8T3WxqYw+AU6DzUwSgeVRc+2pYpCItOj7zihU 8xFgM37pLcWlpBiQoETz/bjYrgs2afTfcVXGetTawHXE1rjuTE6Tr3MmgXpBwrUV0N5V qnq3JnyHBOTTvKWA207IvL1Yn3d175EC8Qek90onVSLw+5+0UmGCZZ4e82V/TxERMwnl ZRlZVS9uwhn8EsJet/LXsaOxnfuIJXsJoD+LymYR8B5Nr4Or+DJIKOLK2DWbQ0U8/Tgc Y3w6vo5P+kRZXgAqx/QxuNMNbBMKd0iXTk/IoDfVvmsyJDkWGgfKHcKfxAYmD+YxD4cB CgVg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20260327; h=cc:to:subject:message-id:date:from:mime-version:dkim-signature; bh=vfZgMXf01YyWza/w6XDTTEtLAovPsjMZYssSpcNLn4E=; fh=a7iGPw1Z+jptRAtoHkTOgQS8Oy4ceWehaw/oB+Vtidw=; b=YkQhHZUsDFg3dhdvOuLRgndGaZhO0wiYjryAfBh9tJtBdkgZvzD1DgDShHU4Qdw5qj iyzpUEfa+yRu/0x33oqVD92YrU6CPwN32ljTbtu3nPRXDY48W7M+P4+HXf5VZfm3TGLH M9nvrJtNMQCpHfMpwtD8OWUHiG2lD6hbKaJjbBBrjNr76PJWhyk+M2c2TRuIEZZ7L1xO oDf+y4C6TdmmSIhhr3aoPZK5Z1q+ykUz75juskJG20msE3AnB1a+5i1HmSuRxVYoX5eW blt9AvvYRUrx5zd9NyDMnhoJI6NgDxB3lpD5gcstQdLFVjlqLdMaJpTN7/3qjAMG8shA WyNw==; darn=vger.kernel.org ARC-Authentication-Results: i=1; mx.google.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1786398211; x=1787003011; darn=vger.kernel.org; h=content-type:cc:to:subject:message-id:date:from:mime-version:from :to:cc:subject:date:message-id:reply-to:content-type; bh=vfZgMXf01YyWza/w6XDTTEtLAovPsjMZYssSpcNLn4E=; b=Kbwz0MBBLeU2Qiv73zSifVu26qov+nqL1B9xNu80mZOixVtQdybNrgYyI0t+9Glw0q tUORWoBz6cX96J9nuFBljG+cGvLTSwrAc4rPY70o4UYSeyNv/eiCGsBIKOq/AEaQlzc5 wqiezy2BiimD1MrKcH/OT5oWIfXVFdl2lw8NPnjLwXW+AN73lb/AZmu8YgAWs+BTOhWq B42IKxC7NYsmM+4xj0PoEvbA4p+NZVKxkSuPylEgitjsJtgoR5s3x5VfMdcMYxSmrfIc N7zBwtZKIpGqU4SmLftM/jZg/aFXzy+44BCJw3tPm71E89e1Z/+o1yGyKscnZWNTDIrj j3hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786398211; x=1787003011; h=content-type:cc:to:subject:message-id:date:from:mime-version :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=vfZgMXf01YyWza/w6XDTTEtLAovPsjMZYssSpcNLn4E=; b=JJmnXFEhCi4V3/3JeHsfdV8/9BKsU8FtbJy9k+MxKgtaxsWRY1MJzpT5u2tSYWj33J FPk+mCsv08R5ZjFG1kW9BoVmtm86EzzKaVaiwm30pKrHjeZ8SblFrQJ+8oeA8KMQUIlP Br3iaJ4bUYap+DZmH0iW2kbHa89gT2QhX61WipRkAMfwCyDRhS15QV5xJKJFZyc7dk3f tbOafbVZVfObGU6uJt279yPfjkTl0zS7AlZSUpY8BpHsg2oeKNILEap93pRLXnJb5ffy 0cQZDvuReIBNl6jM1WquYq/idC1L6yqNEsdV0DnUIjDyZjFkhnVcMbXW6P/gcdbhqOcz i2Kg== X-Forwarded-Encrypted: i=1; AHgh+Rp82m13lbragHPjawadI3jHBaywH+c1C8l9uGSwSy0qSZXLM4zfiuWcMmxVq8NG/evoR9t3V8sccxwAZzA=@vger.kernel.org X-Gm-Message-State: AOJu0YwCyPgqulAy2ize0EXxxFFDoCajz60YZKfbo2Ec2EIITO95a7BR cQC6TbzVGzqwDPMkNG3l/Lk5RtHerNeZJtQ+cW62NZJEAZQ6hfsCRPh1pUBKzVzgAn12Ml5uUxI 8Uigj4pzjwutv3c6N7ZKe4+uBkxGlEkXc86Ep9ja0kFi8GbiEXuhdpcEN X-Gm-Gg: AR+sD13Phxck5+ra5/9CLx3sPC6fZoBFvj28F1+EBpL2lo4WK41T3Nc7evYNWy+3UMd dfH3Et/e89/cteYdbJ7kV8JUm4NR2MManI1Qf0qWFefxyX1bFZMfyvEjZI2lGOHVr6ptqqbymtT cO+qzOYn2T5s9Hbka+XA5xobU87ytUp/wzt3go38dQIN6oO2vn77anEEM/ytasT2nN6sjBplfzY AvZgwZoyV8vpVNl5ewASjDQFE+zIKuitN8jksFc4OvturDMplxqHyqnGUvw5OFS347ghlOJDEl/ m2JQvxPH0g14L5sVMcHjjpA2qBNT2UEdoaF7DQAcPggnWTVDxU/Us3oAcW41aFI2HIz6ynYzEE9 g0Z4xTloKr5Ogf3zN8K1UL5WHhAbD X-Received: by 2002:a05:690c:9208:b0:825:6420:565d with SMTP id 00721157ae682-8256420a92bmr123908127b3.18.1786398210569; Mon, 10 Aug 2026 14:43:30 -0700 (PDT) Received: from 913411032810 named unknown by gmailapi.google.com with HTTPREST; Mon, 10 Aug 2026 14:43:29 -0700 Received: from 913411032810 named unknown by gmailapi.google.com with HTTPREST; Mon, 10 Aug 2026 14:43:29 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Rob Barnes Date: Mon, 10 Aug 2026 14:43:29 -0700 X-Gm-Features: AUfX_mzWWrmycO0IHK1zFyBoKOAF2yQMJEyY9CyRSxFy2vi73KL7wLiw91oAfHc Message-ID: Subject: [PATCH] platform/chrome: cros_ec_proto: Fix deferred response payload handling To: bleung@chromium.org, tzungbi@kernel.org Cc: tomhughes@chromium.org, chrome-platform@lists.linux.dev, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Rob Barnes Subject: [PATCH] platform/chrome: cros_ec_proto: Fix deferred response payload handling 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. Save and restore orig_msg fields (command, outsize, version) around the resend request to prevent unintended caller struct mutations. Update existing KUnit tests and add test cases for 4-byte and 16-byte response payloads. Signed-off-by: Rob Barnes --- drivers/platform/chrome/cros_ec_proto.c | 25 ++- drivers/platform/chrome/cros_ec_proto_test.c | 151 +++++++++++++++++- 2 files changed, 168 insertions(+), 8 deletions(-) diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index a655322b599e..45d6e9bce746 100644 --- a/drivers/platform/chrome/cros_ec_proto.c +++ b/drivers/platform/chrome/cros_ec_proto.c @@ -147,7 +147,7 @@ static int prepare_tx_legacy(struct cros_ec_device *ec_= dev, return EC_MSG_TX_PROTO_BYTES + msg->outsize; } -static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result) +static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, + struct cros_ec_command *orig_msg) { struct { struct cros_ec_command msg; @@ -162,7 +162,7 @@ static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t * if (ret < 0) return ret; - *result =3D msg->result; + orig_msg->result =3D msg->result; if (msg->result !=3D EC_RES_SUCCESS) return ret; @@ -170,8 +170,28 @@ static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t * break; } - if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) - return ret; + if (!(status->flags & EC_COMMS_STATUS_PROCESSING)) { + /* + * If original command requested response payload, retrieve it via + * EC_CMD_RESEND_RESPONSE into orig_msg->data. Otherwise return 0 + * for zero-payload commands. + */ + if (orig_msg->insize > 0) { + uint32_t orig_cmd =3D orig_msg->command; + uint32_t orig_outsize =3D orig_msg->outsize; + uint32_t 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; + } + return 0; + } } if (i >=3D EC_COMMAND_RETRIES) @@ -185,7 +205,7 @@ 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); 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); return ret; } diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c index 63e38671e95a..609ac8c5108f 100644 --- a/drivers/platform/chrome/cros_ec_proto_test.c +++ b/drivers/platform/chrome/cros_ec_proto_test.c @@ -1756,7 +1756,7 @@ static void cros_ec_proto_test_cmd_xfer_protocol_v2_no_op(struct kunit *test) KUNIT_EXPECT_EQ(test, ret, -EIO); } -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_0bytes(struct kunit *test) { struct cros_ec_proto_test_priv *priv =3D test->priv; struct cros_ec_device *ec_dev =3D &priv->ec_dev; @@ -1786,7 +1786,7 @@ static void cros_ec_proto_test_cmd_xfer_in_progress_normal(struct kunit *test) } 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); KUNIT_EXPECT_EQ(test, msg.result, EC_RES_SUCCESS); @@ -1811,6 +1811,149 @@ 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); } +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->outsize =3D 2; + msg->insize =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->outsize, 2); + 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(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[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->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, 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.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; @@ -2715,7 +2858,9 @@ 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_0bytes), + 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 2.45.0