forked from Minki/linux
68a838b84e
MHI channel may generates event/interrupt right after enabling.
It may leads to 2 race conditions issues.
1)
Such event may be dropped by qcom_mhi_qrtr_dl_callback() at check:
if (!qdev || mhi_res->transaction_status)
return;
Because dev_set_drvdata(&mhi_dev->dev, qdev) may be not performed at
this moment. In this situation qrtr-ns will be unable to enumerate
services in device.
---------------------------------------------------------------
2)
Such event may come at the moment after dev_set_drvdata() and
before qrtr_endpoint_register(). In this case kernel will panic with
accessing wrong pointer at qcom_mhi_qrtr_dl_callback():
rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
mhi_res->bytes_xferd);
Because endpoint is not created yet.
--------------------------------------------------------------
So move mhi_prepare_for_transfer_autoqueue after endpoint creation
to fix it.
Fixes: a2e2cc0dbb ("net: qrtr: Start MHI channels during init")
Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Reviewed-by: Hemant Kumar <quic_hemantk@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
138 lines
3.0 KiB
C
138 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
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*/
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#include <linux/mhi.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <net/sock.h>
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#include "qrtr.h"
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struct qrtr_mhi_dev {
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struct qrtr_endpoint ep;
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struct mhi_device *mhi_dev;
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struct device *dev;
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};
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/* From MHI to QRTR */
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static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
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struct mhi_result *mhi_res)
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{
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struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
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int rc;
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if (!qdev || mhi_res->transaction_status)
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return;
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rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
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mhi_res->bytes_xferd);
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if (rc == -EINVAL)
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dev_err(qdev->dev, "invalid ipcrouter packet\n");
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}
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/* From QRTR to MHI */
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static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,
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struct mhi_result *mhi_res)
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{
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struct sk_buff *skb = mhi_res->buf_addr;
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if (skb->sk)
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sock_put(skb->sk);
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consume_skb(skb);
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}
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/* Send data over MHI */
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static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
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{
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struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);
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int rc;
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if (skb->sk)
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sock_hold(skb->sk);
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rc = skb_linearize(skb);
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if (rc)
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goto free_skb;
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rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
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MHI_EOT);
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if (rc)
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goto free_skb;
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return rc;
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free_skb:
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if (skb->sk)
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sock_put(skb->sk);
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kfree_skb(skb);
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return rc;
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}
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static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
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const struct mhi_device_id *id)
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{
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struct qrtr_mhi_dev *qdev;
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int rc;
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qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
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if (!qdev)
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return -ENOMEM;
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qdev->mhi_dev = mhi_dev;
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qdev->dev = &mhi_dev->dev;
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qdev->ep.xmit = qcom_mhi_qrtr_send;
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dev_set_drvdata(&mhi_dev->dev, qdev);
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rc = qrtr_endpoint_register(&qdev->ep, QRTR_EP_NID_AUTO);
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if (rc)
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return rc;
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/* start channels */
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rc = mhi_prepare_for_transfer_autoqueue(mhi_dev);
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if (rc) {
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qrtr_endpoint_unregister(&qdev->ep);
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return rc;
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}
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dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
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return 0;
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}
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static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
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{
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struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
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qrtr_endpoint_unregister(&qdev->ep);
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mhi_unprepare_from_transfer(mhi_dev);
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dev_set_drvdata(&mhi_dev->dev, NULL);
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}
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static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
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{ .chan = "IPCR" },
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{}
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};
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MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
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static struct mhi_driver qcom_mhi_qrtr_driver = {
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.probe = qcom_mhi_qrtr_probe,
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.remove = qcom_mhi_qrtr_remove,
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.dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
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.ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
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.id_table = qcom_mhi_qrtr_id_table,
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.driver = {
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.name = "qcom_mhi_qrtr",
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},
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};
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module_mhi_driver(qcom_mhi_qrtr_driver);
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MODULE_AUTHOR("Chris Lew <clew@codeaurora.org>");
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MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
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MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
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MODULE_LICENSE("GPL v2");
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