From nobody Tue Nov 26 05:47:21 2024 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3B4B31E0B96; Mon, 21 Oct 2024 13:19:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729516763; cv=none; b=NkLo48xN0OQbzrK7vzm3i+KNkS3VF95A9/3cTOlwBSoH6R6TO+LejT5TWZRXxSLA2xMNOLjKyo5mWfMb2oyGzbef6IJPwZha1IHkHWIOGADW1kxTqwIgvoSBDOuDRkXdvjk+cWa8FC5dfJ9olZkj2jiHOJDbZzRR5N33+XQUwJA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729516763; c=relaxed/simple; bh=fN8/CgKj3jJU9zdFPli8qQkTQ7X5G/HUovnFn/qYabk=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=K8OgPX1wAds1xYN0sBjXP1fRAYVaIbwQ9finG8qZ39U1Z1Njc8IvWiO4ka8sNRj8AHZvuZrA28JjliDEvD4wLTaWa4pY6QAh/XkRbN/td5H4EBdNlJqA1I+r1A3j/91jOFQvD3L4eRFjonZTUojbTL5gQjjf0GSBAGH3lojk6SY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=JZXV8mmZ; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="JZXV8mmZ" Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49L9fQvC000739; Mon, 21 Oct 2024 13:19:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-type:date:from:message-id:mime-version:subject:to; s= qcppdkim1; bh=8Pj7g62BnpTOi3u3ZuTsxArKua2YZFJAJxMs8s4ddoc=; b=JZ XV8mmZbJphLECAEKanjJXIh/0wp9dZ+50zpUqP8Dk7iXdaioKmQhZ8clfEoGG5Ki mMdmqTUwzFhfESHvmf5wa4y6QQCpQNar7MHuaHqDJ0lmyqWeAdtHUgy4dRrzUIjK JpamJc0TA0uRIIkOAO/QUXR9URYHQj/fALxU45Gg5Yt822vYsqO2gd7p8pwSfqT/ L83KVVs3G9jsLQ4PHLWQJJcuxF4NwaGmwumpHnh64xBIgDylckYLi0Znn9DUFTaf YWHJ48T/1oJnVP+bwSoRj8cBtF/5FBn2/ejXvpcon1pgzfw//FSqWJgscTKcEpRM MBYsyfiTF2W+mIbilygg== Received: from nasanppmta02.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 42dmj10sg5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 21 Oct 2024 13:19:17 +0000 (GMT) Received: from nasanex01a.na.qualcomm.com (nasanex01a.na.qualcomm.com [10.52.223.231]) by NASANPPMTA02.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 49LDJGYO007636 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 21 Oct 2024 13:19:16 GMT Received: from hu-faisalh-hyd.qualcomm.com (10.80.80.8) by nasanex01a.na.qualcomm.com (10.52.223.231) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Mon, 21 Oct 2024 06:19:14 -0700 From: Faisal Hassan To: Greg Kroah-Hartman , Mathias Nyman CC: , , Faisal Hassan , Subject: [PATCH v2] xhci: Fix Link TRB DMA in command ring stopped completion event Date: Mon, 21 Oct 2024 18:49:04 +0530 Message-ID: <20241021131904.20678-1-quic_faisalh@quicinc.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01a.na.qualcomm.com (10.52.223.231) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: zgONXSfcHytGlMCGPm8K7vtHvR-Ya4c7 X-Proofpoint-ORIG-GUID: zgONXSfcHytGlMCGPm8K7vtHvR-Ya4c7 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 adultscore=0 suspectscore=0 spamscore=0 lowpriorityscore=0 malwarescore=0 priorityscore=1501 clxscore=1015 mlxlogscore=961 phishscore=0 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410210095 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" During the aborting of a command, the software receives a command completion event for the command ring stopped, with the TRB pointing to the next TRB after the aborted command. If the command we abort is located just before the Link TRB in the command ring, then during the 'command ring stopped' completion event, the xHC gives the Link TRB in the event's cmd DMA, which causes a mismatch in handling command completion event. To handle this situation, an additional check has been added to ignore the mismatch error and continue the operation. Fixes: 7f84eef0dafb ("USB: xhci: No-op command queueing and irq handler.") Cc: stable@vger.kernel.org Signed-off-by: Faisal Hassan --- Changes in v2: - Removed traversing of TRBs with in_range() API. - Simplified the if condition check. v1 link: https://lore.kernel.org/all/20241018195953.12315-1-quic_faisalh@quicinc.com drivers/usb/host/xhci-ring.c | 43 +++++++++++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 5 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index b2950c35c740..de375c9f08ca 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -126,6 +126,29 @@ static void inc_td_cnt(struct urb *urb) urb_priv->num_tds_done++; } =20 +/* + * Return true if the DMA is pointing to a Link TRB in the ring; + * otherwise, return false. + */ +static bool is_dma_link_trb(struct xhci_ring *ring, dma_addr_t dma) +{ + struct xhci_segment *seg; + union xhci_trb *trb; + + seg =3D ring->first_seg; + do { + if (in_range(dma, seg->dma, TRB_SEGMENT_SIZE)) { + /* found the TRB, check if it's link */ + trb =3D &seg->trbs[(dma - seg->dma) / sizeof(*trb)]; + return trb_is_link(trb); + } + + seg =3D seg->next; + } while (seg !=3D ring->first_seg); + + return false; +} + static void trb_to_noop(union xhci_trb *trb, u32 noop_type) { if (trb_is_link(trb)) { @@ -1718,6 +1741,7 @@ static void handle_cmd_completion(struct xhci_hcd *xh= ci, =20 trace_xhci_handle_command(xhci->cmd_ring, &cmd_trb->generic); =20 + cmd_comp_code =3D GET_COMP_CODE(le32_to_cpu(event->status)); cmd_dequeue_dma =3D xhci_trb_virt_to_dma(xhci->cmd_ring->deq_seg, cmd_trb); /* @@ -1725,17 +1749,26 @@ static void handle_cmd_completion(struct xhci_hcd *= xhci, * command. */ if (!cmd_dequeue_dma || cmd_dma !=3D (u64)cmd_dequeue_dma) { - xhci_warn(xhci, - "ERROR mismatched command completion event\n"); - return; + /* + * For the 'command ring stopped' completion event, there + * is a risk of a mismatch in dequeue pointers if we abort + * the command just before the link TRB in the command ring. + * In this scenario, the cmd_dma in the event would point + * to a link TRB, while the software dequeue pointer circles + * back to the start. + */ + if (!(cmd_comp_code =3D=3D COMP_COMMAND_RING_STOPPED && + is_dma_link_trb(xhci->cmd_ring, cmd_dma))) { + xhci_warn(xhci, + "ERROR mismatched command completion event\n"); + return; + } } =20 cmd =3D list_first_entry(&xhci->cmd_list, struct xhci_command, cmd_list); =20 cancel_delayed_work(&xhci->cmd_timer); =20 - cmd_comp_code =3D GET_COMP_CODE(le32_to_cpu(event->status)); - /* If CMD ring stopped we own the trbs between enqueue and dequeue */ if (cmd_comp_code =3D=3D COMP_COMMAND_RING_STOPPED) { complete_all(&xhci->cmd_ring_stop_completion); --=20 2.17.1