[PATCH v2] HID: hyperv: streamline driver probe to avoid devres issues

[PATCH v2] HID: hyperv: streamline driver probe to avoid devres issues

[Vitaly Kuznetsov]

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>
---
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

RE: [PATCH v2] HID: hyperv: streamline driver probe to avoid devres issues

[Michael Kelley]

From: Vitaly Kuznetsov <vkuznets@redhat.com> 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]
>   ...
> 
> 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>
> ---
> 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@outlook.com>

Re: [PATCH v2] HID: hyperv: streamline driver probe to avoid devres issues

[Saurabh Singh Sengar]

On Mon, Nov 11, 2024 at 04:50:24PM +0000, Michael Kelley wrote:
> From: Vitaly Kuznetsov <vkuznets@redhat.com> 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:

[   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@outlook.com>
> > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> > ---
> > 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@outlook.com>

Tested V2 as well, please feel free to  add,
Tested-by: Saurabh Sengar <ssengar@linux.microsoft.com>

Re: [PATCH v2] HID: hyperv: streamline driver probe to avoid devres issues

[Vitaly Kuznetsov]

Saurabh Singh Sengar <ssengar@linux.microsoft.com> writes:

> On Mon, Nov 11, 2024 at 04:50:24PM +0000, Michael Kelley wrote:
>> From: Vitaly Kuznetsov <vkuznets@redhat.com> 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@outlook.com>
>> > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>> > ---
>> > 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@outlook.com>
>
> Tested V2 as well, please feel free to  add,
> Tested-by: Saurabh Sengar <ssengar@linux.microsoft.com>

Thank you!

-- 
Vitaly

Re: [PATCH v2] HID: hyperv: streamline driver probe to avoid devres issues

[Jiri Kosina]

On Tue, 12 Nov 2024, Vitaly Kuznetsov wrote:

> >> Reviewed-by: Michael Kelley <mhklinux@outlook.com>
> >
> > Tested V2 as well, please feel free to  add,
> > Tested-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> 
> Thank you!

Applied to hid.git, thanks!

-- 
Jiri Kosina
SUSE Labs