Saurabh Singh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx> writes:
> On Mon, Nov 11, 2024 at 04:50:24PM +0000, Michael Kelley wrote:
>> From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Sent: Monday, November 11, 2024 5:13 AM
>> >
>> > 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]
>> > ...
>
> Do we want to mention the other error as well this patch is fixing:
The error itself is likely the same ('hid_dev->driver' override with
'mousevsc_hid_driver' stub which doesn't do anything) but the trace
stack is a bit different, yes.
>
> [ 68.237679] ------------[ cut here ]------------
> [ 68.237681] WARNING: CPU: 23 PID: 579 at drivers/hid/hid-core.c:1262 hid_open_report+0x2c0/0x350 [hid]
> <snip>
> [ 68.237741] RIP: 0010:hid_open_report+0x2c0/0x350 [hid]
> [ 68.237765] Call Trace:
> [ 68.237767] <TASK>
> [ 68.237769] ? show_regs+0x6c/0x80
> [ 68.237774] ? __warn+0x8d/0x150
> [ 68.237777] ? hid_open_report+0x2c0/0x350 [hid]
> [ 68.237784] ? report_bug+0x182/0x1b0
> [ 68.237788] ? handle_bug+0x6e/0xb0
> [ 68.237791] ? exc_invalid_op+0x18/0x80
> [ 68.237794] ? asm_exc_invalid_op+0x1b/0x20
> [ 68.237799] ? hid_open_report+0x2c0/0x350 [hid]
> [ 68.237805] mousevsc_probe+0x1d5/0x250 [hid_hyperv]
> [ 68.237808] vmbus_probe+0x3b/0xa0 [hv_vmbus]
> [ 68.237822] really_probe+0xee/0x3c0
> [ 68.237827] __driver_probe_device+0x8c/0x180
> [ 68.237830] driver_probe_device+0x24/0xd0
> [ 68.237832] __driver_attach_async_helper+0x6e/0x110
> [ 68.237835] async_run_entry_fn+0x30/0x130
> [ 68.237837] process_one_work+0x178/0x3d0
> [ 68.237839] worker_thread+0x2de/0x410
> [ 68.237841] ? __pfx_worker_thread+0x10/0x10
> [ 68.237843] kthread+0xe1/0x110
> [ 68.237847] ? __pfx_kthread+0x10/0x10
> [ 68.237849] ret_from_fork+0x44/0x70
> [ 68.237852] ? __pfx_kthread+0x10/0x10
> [ 68.237854] ret_from_fork_asm+0x1a/0x30
> [ 68.237858] </TASK>
> [ 68.237859] ---[ end trace 0000000000000000 ]---
> [ 68.237861] hid-generic 0006:045E:0621.0002: parse failed
> [ 68.238276] hv_vmbus: probe failed for device 58f75a6d-d949-4320-99e1-a2a2576d581c (-19)
>
>
>> >
>> > 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@xxxxxxxxxxx>
>> > Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
>> > ---
>> > Changes since v1:
>> > - Keep custom HID driver for mousevsc but do it properly
>> > [Michael Kelley].
>> > - Add 'Fixes:' tag [Saurabh Singh Sengar].
>> > ---
>> > 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 f33485d83d24..0fb210e40a41 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");
>> > --
>> > 2.47.0
>>
>> Reviewed-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
>
> Tested V2 as well, please feel free to add,
> Tested-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx>
Thank you!
--
Vitaly
