6.6-stable review patch. If anyone has any objections, please let me know.
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From: Vitaly Kuznetsov vkuznets@redhat.com
[ Upstream commit 66ef47faa90d838cda131fe1f7776456cc3b59f2 ]
It was found that unloading 'hid_hyperv' module results in a devres complaint:
... hv_vmbus: unregistering driver hid_hyperv ------------[ cut here ]------------ WARNING: CPU: 2 PID: 3983 at drivers/base/devres.c:691 devres_release_group+0x1f2/0x2c0 ... Call Trace: <TASK> ? devres_release_group+0x1f2/0x2c0 ? __warn+0xd1/0x1c0 ? devres_release_group+0x1f2/0x2c0 ? report_bug+0x32a/0x3c0 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x18/0x50 ? asm_exc_invalid_op+0x1a/0x20 ? devres_release_group+0x1f2/0x2c0 ? devres_release_group+0x90/0x2c0 ? rcu_is_watching+0x15/0xb0 ? __pfx_devres_release_group+0x10/0x10 hid_device_remove+0xf5/0x220 device_release_driver_internal+0x371/0x540 ? klist_put+0xf3/0x170 bus_remove_device+0x1f1/0x3f0 device_del+0x33f/0x8c0 ? __pfx_device_del+0x10/0x10 ? cleanup_srcu_struct+0x337/0x500 hid_destroy_device+0xc8/0x130 mousevsc_remove+0xd2/0x1d0 [hid_hyperv] device_release_driver_internal+0x371/0x540 driver_detach+0xc5/0x180 bus_remove_driver+0x11e/0x2a0 ? __mutex_unlock_slowpath+0x160/0x5e0 vmbus_driver_unregister+0x62/0x2b0 [hv_vmbus] ...
And the issue seems to be that the corresponding devres group is not allocated. Normally, devres_open_group() is called from __hid_device_probe() but Hyper-V HID driver overrides 'hid_dev->driver' with 'mousevsc_hid_driver' stub and basically re-implements __hid_device_probe() by calling hid_parse() and hid_hw_start() but not devres_open_group(). hid_device_probe() does not call __hid_device_probe() for it. Later, when the driver is removed, hid_device_remove() calls devres_release_group() as it doesn't check whether hdev->driver was initially overridden or not.
The issue seems to be related to the commit 62c68e7cee33 ("HID: ensure timely release of driver-allocated resources") but the commit itself seems to be correct.
Fix the issue by dropping the 'hid_dev->driver' override and using hid_register_driver()/hid_unregister_driver() instead. Alternatively, it would have been possible to rely on the default handling but HID_CONNECT_DEFAULT implies HID_CONNECT_HIDRAW and it doesn't seem to work for mousevsc as-is.
Fixes: 62c68e7cee33 ("HID: ensure timely release of driver-allocated resources") Suggested-by: Michael Kelley mhklinux@outlook.com Signed-off-by: Vitaly Kuznetsov vkuznets@redhat.com Reviewed-by: Michael Kelley mhklinux@outlook.com Tested-by: Saurabh Sengar ssengar@linux.microsoft.com Signed-off-by: Jiri Kosina jkosina@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hid/hid-hyperv.c | 58 ++++++++++++++++++++++++++++------------ 1 file changed, 41 insertions(+), 17 deletions(-)
diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c index f33485d83d24f..0fb210e40a412 100644 --- a/drivers/hid/hid-hyperv.c +++ b/drivers/hid/hid-hyperv.c @@ -422,6 +422,25 @@ static int mousevsc_hid_raw_request(struct hid_device *hid, return 0; }
+static int mousevsc_hid_probe(struct hid_device *hid_dev, const struct hid_device_id *id) +{ + int ret; + + ret = hid_parse(hid_dev); + if (ret) { + hid_err(hid_dev, "parse failed\n"); + return ret; + } + + ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV); + if (ret) { + hid_err(hid_dev, "hw start failed\n"); + return ret; + } + + return 0; +} + static const struct hid_ll_driver mousevsc_ll_driver = { .parse = mousevsc_hid_parse, .open = mousevsc_hid_open, @@ -431,7 +450,16 @@ static const struct hid_ll_driver mousevsc_ll_driver = { .raw_request = mousevsc_hid_raw_request, };
-static struct hid_driver mousevsc_hid_driver; +static const struct hid_device_id mousevsc_devices[] = { + { HID_DEVICE(BUS_VIRTUAL, HID_GROUP_ANY, 0x045E, 0x0621) }, + { } +}; + +static struct hid_driver mousevsc_hid_driver = { + .name = "hid-hyperv", + .id_table = mousevsc_devices, + .probe = mousevsc_hid_probe, +};
static int mousevsc_probe(struct hv_device *device, const struct hv_vmbus_device_id *dev_id) @@ -473,7 +501,6 @@ static int mousevsc_probe(struct hv_device *device, }
hid_dev->ll_driver = &mousevsc_ll_driver; - hid_dev->driver = &mousevsc_hid_driver; hid_dev->bus = BUS_VIRTUAL; hid_dev->vendor = input_dev->hid_dev_info.vendor; hid_dev->product = input_dev->hid_dev_info.product; @@ -488,20 +515,6 @@ static int mousevsc_probe(struct hv_device *device, if (ret) goto probe_err2;
- - ret = hid_parse(hid_dev); - if (ret) { - hid_err(hid_dev, "parse failed\n"); - goto probe_err2; - } - - ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV); - - if (ret) { - hid_err(hid_dev, "hw start failed\n"); - goto probe_err2; - } - device_init_wakeup(&device->device, true);
input_dev->connected = true; @@ -579,12 +592,23 @@ static struct hv_driver mousevsc_drv = {
static int __init mousevsc_init(void) { - return vmbus_driver_register(&mousevsc_drv); + int ret; + + ret = hid_register_driver(&mousevsc_hid_driver); + if (ret) + return ret; + + ret = vmbus_driver_register(&mousevsc_drv); + if (ret) + hid_unregister_driver(&mousevsc_hid_driver); + + return ret; }
static void __exit mousevsc_exit(void) { vmbus_driver_unregister(&mousevsc_drv); + hid_unregister_driver(&mousevsc_hid_driver); }
MODULE_LICENSE("GPL");