2023-02-07 11:55:41

by Winkler, Tomas

Subject: [char-misc-next 1/2] mei: bus: disallow driver match while dismantling device

From: Alexander Usyskin <[email protected]>

With immediate reply support to enum request and
FW reset, a device on MEI bus can be temporarily removed.
A driver for a device on MEI bus can try to bind to the device
right between bus attempt to remove driver and device
structures removal.
This leaves device driver with pointers to freed memory
of device structures.

Avoid bus device driver bind while dismantling device by
disallowing device match right before driver release.

Signed-off-by: Alexander Usyskin <[email protected]>
Signed-off-by: Tomas Winkler <[email protected]>
---
drivers/misc/mei/bus.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index a81b890c7ee6..71d53d7ffdba 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (c) 2012-2019, Intel Corporation. All rights reserved.
+ * Copyright (c) 2012-2023, Intel Corporation. All rights reserved.
* Intel Management Engine Interface (Intel MEI) Linux driver
*/

@@ -1392,6 +1392,7 @@ static int mei_cl_bus_dev_add(struct mei_cl_device *cldev)
*/
static void mei_cl_bus_dev_stop(struct mei_cl_device *cldev)
{
+ cldev->do_match = 0;
if (cldev->is_added)
device_release_driver(&cldev->dev);
}
--
2.39.1

2023-02-07 11:55:43

by Winkler, Tomas

Subject: [char-misc-next 2/2] mei: lower the log level for non-fatal failed messages

From: Vitaly Lubart <[email protected]>

Some non-fatal log messages should be logged at INFO log level
because failure to send/receive them is not breaking mei functionality
and may happen during legal firmware resets

Signed-off-by: Vitaly Lubart <[email protected]>
Signed-off-by: Tomas Winkler <[email protected]>
---
drivers/misc/mei/bus-fixup.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 92c0930cc742..211536109308 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (c) 2013-2022, Intel Corporation. All rights reserved.
+ * Copyright (c) 2013-2023, Intel Corporation. All rights reserved.
* Intel Management Engine Interface (Intel MEI) Linux driver
*/

@@ -151,7 +151,7 @@ static int mei_fwver(struct mei_cl_device *cldev)
ret = __mei_cl_send(cldev->cl, (u8 *)&req, sizeof(req), 0,
MEI_CL_IO_TX_BLOCKING);
if (ret < 0) {
- dev_err(&cldev->dev, "Could not send ReqFWVersion cmd ret = %d\n", ret);
+ dev_info(&cldev->dev, "Could not send ReqFWVersion cmd ret = %d\n", ret);
return ret;
}

@@ -163,7 +163,7 @@ static int mei_fwver(struct mei_cl_device *cldev)
* Should be at least one version block,
* error out if nothing found
*/
- dev_err(&cldev->dev, "Could not read FW version ret = %d\n", bytes_recv);
+ dev_info(&cldev->dev, "Could not read FW version ret = %d\n", bytes_recv);
return -EIO;
}

@@ -220,15 +220,15 @@ static void mei_mkhi_fix(struct mei_cl_device *cldev)
if (cldev->bus->fw_f_fw_ver_supported) {
ret = mei_fwver(cldev);
if (ret < 0)
- dev_err(&cldev->dev, "FW version command failed %d\n",
- ret);
+ dev_info(&cldev->dev, "FW version command failed %d\n",
+ ret);
}

if (cldev->bus->hbm_f_os_supported) {
ret = mei_osver(cldev);
if (ret < 0)
- dev_err(&cldev->dev, "OS version command failed %d\n",
- ret);
+ dev_info(&cldev->dev, "OS version command failed %d\n",
+ ret);
}
mei_cldev_disable(cldev);
}
@@ -247,7 +247,7 @@ static void mei_gsc_mkhi_ver(struct mei_cl_device *cldev)

ret = mei_fwver(cldev);
if (ret < 0)
- dev_err(&cldev->dev, "FW version command failed %d\n", ret);
+ dev_info(&cldev->dev, "FW version command failed %d\n", ret);
mei_cldev_disable(cldev);
}

@@ -278,8 +278,8 @@ static void mei_gsc_mkhi_fix_ver(struct mei_cl_device *cldev)

ret = mei_fwver(cldev);
if (ret < 0)
- dev_err(&cldev->dev, "FW version command failed %d\n",
- ret);
+ dev_info(&cldev->dev, "FW version command failed %d\n",
+ ret);
out:
mei_cldev_disable(cldev);
}
@@ -403,7 +403,7 @@ static int mei_nfc_if_version(struct mei_cl *cl,
memcpy(ver, reply->data, sizeof(*ver));

dev_info(bus->dev, "NFC MEI VERSION: IVN 0x%x Vendor ID 0x%x Type 0x%x\n",
- ver->fw_ivn, ver->vendor_id, ver->radio_type);
+ ver->fw_ivn, ver->vendor_id, ver->radio_type);

err:
kfree(reply);
--
2.39.1