* [PATCH v2] bluetooth: bcm203x: update the reference count of udev
@ 2021-07-31 15:41 Salah Triki
2021-07-31 16:10 ` [v2] " bluez.test.bot
2021-08-01 18:01 ` [PATCH v2] " Marcel Holtmann
0 siblings, 2 replies; 5+ messages in thread
From: Salah Triki @ 2021-07-31 15:41 UTC (permalink / raw)
To: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz, gregkh
Cc: linux-bluetooth, linux-kernel
Use usb_get_dev() to increment the reference count of the usb device
structure in order to avoid releasing the structure while it is still in
use. And use usb_put_dev() to decrement the reference count and thus,
when it will be equal to 0 the structure will be released.
Signed-off-by: Salah Triki <salah.triki@gmail.com>
---
Change since v1:
Modification of the description
drivers/bluetooth/bcm203x.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/bluetooth/bcm203x.c b/drivers/bluetooth/bcm203x.c
index e667933c3d70..547d35425d70 100644
--- a/drivers/bluetooth/bcm203x.c
+++ b/drivers/bluetooth/bcm203x.c
@@ -166,7 +166,7 @@ static int bcm203x_probe(struct usb_interface *intf, const struct usb_device_id
if (!data)
return -ENOMEM;
- data->udev = udev;
+ data->udev = usb_get_dev(udev);
data->state = BCM203X_LOAD_MINIDRV;
data->urb = usb_alloc_urb(0, GFP_KERNEL);
@@ -244,6 +244,8 @@ static void bcm203x_disconnect(struct usb_interface *intf)
usb_set_intfdata(intf, NULL);
+ usb_put_dev(data->udev);
+
usb_free_urb(data->urb);
kfree(data->fw_data);
kfree(data->buffer);
--
2.25.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* RE: [v2] bluetooth: bcm203x: update the reference count of udev
2021-07-31 15:41 [PATCH v2] bluetooth: bcm203x: update the reference count of udev Salah Triki
@ 2021-07-31 16:10 ` bluez.test.bot
2021-08-01 18:01 ` [PATCH v2] " Marcel Holtmann
1 sibling, 0 replies; 5+ messages in thread
From: bluez.test.bot @ 2021-07-31 16:10 UTC (permalink / raw)
To: linux-bluetooth, salah.triki
[-- Attachment #1: Type: text/plain, Size: 2727 bytes --]
This is automated email and please do not reply to this email!
Dear submitter,
Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=524445
---Test result---
Test Summary:
CheckPatch PASS 0.42 seconds
GitLint PASS 0.10 seconds
BuildKernel PASS 510.97 seconds
TestRunner: Setup PASS 338.30 seconds
TestRunner: l2cap-tester PASS 2.55 seconds
TestRunner: bnep-tester PASS 1.92 seconds
TestRunner: mgmt-tester PASS 30.45 seconds
TestRunner: rfcomm-tester PASS 2.12 seconds
TestRunner: sco-tester PASS 2.07 seconds
TestRunner: smp-tester FAIL 2.10 seconds
TestRunner: userchan-tester PASS 1.94 seconds
Details
##############################
Test: CheckPatch - PASS - 0.42 seconds
Run checkpatch.pl script with rule in .checkpatch.conf
##############################
Test: GitLint - PASS - 0.10 seconds
Run gitlint with rule in .gitlint
##############################
Test: BuildKernel - PASS - 510.97 seconds
Build Kernel with minimal configuration supports Bluetooth
##############################
Test: TestRunner: Setup - PASS - 338.30 seconds
Setup environment for running Test Runner
##############################
Test: TestRunner: l2cap-tester - PASS - 2.55 seconds
Run test-runner with l2cap-tester
Total: 40, Passed: 40 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: bnep-tester - PASS - 1.92 seconds
Run test-runner with bnep-tester
Total: 1, Passed: 1 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: mgmt-tester - PASS - 30.45 seconds
Run test-runner with mgmt-tester
Total: 448, Passed: 445 (99.3%), Failed: 0, Not Run: 3
##############################
Test: TestRunner: rfcomm-tester - PASS - 2.12 seconds
Run test-runner with rfcomm-tester
Total: 9, Passed: 9 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: sco-tester - PASS - 2.07 seconds
Run test-runner with sco-tester
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner: smp-tester - FAIL - 2.10 seconds
Run test-runner with smp-tester
Total: 8, Passed: 7 (87.5%), Failed: 1, Not Run: 0
Failed Test Cases
SMP Client - SC Request 2 Failed 0.021 seconds
##############################
Test: TestRunner: userchan-tester - PASS - 1.94 seconds
Run test-runner with userchan-tester
Total: 3, Passed: 3 (100.0%), Failed: 0, Not Run: 0
---
Regards,
Linux Bluetooth
[-- Attachment #2: l2cap-tester.log --]
[-- Type: application/octet-stream, Size: 44385 bytes --]
[-- Attachment #3: bnep-tester.log --]
[-- Type: application/octet-stream, Size: 3593 bytes --]
[-- Attachment #4: mgmt-tester.log --]
[-- Type: application/octet-stream, Size: 616863 bytes --]
[-- Attachment #5: rfcomm-tester.log --]
[-- Type: application/octet-stream, Size: 11713 bytes --]
[-- Attachment #6: sco-tester.log --]
[-- Type: application/octet-stream, Size: 9946 bytes --]
[-- Attachment #7: smp-tester.log --]
[-- Type: application/octet-stream, Size: 11741 bytes --]
[-- Attachment #8: userchan-tester.log --]
[-- Type: application/octet-stream, Size: 5490 bytes --]
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] bluetooth: bcm203x: update the reference count of udev
2021-07-31 15:41 [PATCH v2] bluetooth: bcm203x: update the reference count of udev Salah Triki
2021-07-31 16:10 ` [v2] " bluez.test.bot
@ 2021-08-01 18:01 ` Marcel Holtmann
2021-08-02 19:34 ` Salah Triki
1 sibling, 1 reply; 5+ messages in thread
From: Marcel Holtmann @ 2021-08-01 18:01 UTC (permalink / raw)
To: Salah Triki
Cc: Johan Hedberg, Luiz Augusto von Dentz, Greg Kroah-Hartman, BlueZ,
open list, Alan Stern, Oliver Neukum
Hi Salah,
> Use usb_get_dev() to increment the reference count of the usb device
> structure in order to avoid releasing the structure while it is still in
> use. And use usb_put_dev() to decrement the reference count and thus,
> when it will be equal to 0 the structure will be released.
>
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> ---
> Change since v1:
> Modification of the description
>
> drivers/bluetooth/bcm203x.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bluetooth/bcm203x.c b/drivers/bluetooth/bcm203x.c
> index e667933c3d70..547d35425d70 100644
> --- a/drivers/bluetooth/bcm203x.c
> +++ b/drivers/bluetooth/bcm203x.c
> @@ -166,7 +166,7 @@ static int bcm203x_probe(struct usb_interface *intf, const struct usb_device_id
> if (!data)
> return -ENOMEM;
>
> - data->udev = udev;
> + data->udev = usb_get_dev(udev);
> data->state = BCM203X_LOAD_MINIDRV;
>
> data->urb = usb_alloc_urb(0, GFP_KERNEL);
> @@ -244,6 +244,8 @@ static void bcm203x_disconnect(struct usb_interface *intf)
>
> usb_set_intfdata(intf, NULL);
>
> + usb_put_dev(data->udev);
> +
> usb_free_urb(data->urb);
> kfree(data->fw_data);
> kfree(data->buffer);
I do not understand this. If this is something broken, then it is broken in
btusb.c as well and that driver is heavily used by all sorts of devices. So
we should have seen bug reports about this.
Regards
Marcel
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] bluetooth: bcm203x: update the reference count of udev
2021-08-01 18:01 ` [PATCH v2] " Marcel Holtmann
@ 2021-08-02 19:34 ` Salah Triki
2021-08-02 20:16 ` Alan Stern
0 siblings, 1 reply; 5+ messages in thread
From: Salah Triki @ 2021-08-02 19:34 UTC (permalink / raw)
To: Marcel Holtmann
Cc: Johan Hedberg, Luiz Augusto von Dentz, Greg Kroah-Hartman,
open list, Alan Stern, Oliver Neukum
On Sun, Aug 01, 2021 at 08:01:06PM +0200, Marcel Holtmann wrote:
> Hi Salah,
>
> > Use usb_get_dev() to increment the reference count of the usb device
> > structure in order to avoid releasing the structure while it is still in
> > use. And use usb_put_dev() to decrement the reference count and thus,
> > when it will be equal to 0 the structure will be released.
> >
> > Signed-off-by: Salah Triki <salah.triki@gmail.com>
> > ---
> > Change since v1:
> > Modification of the description
> >
> > drivers/bluetooth/bcm203x.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/bluetooth/bcm203x.c b/drivers/bluetooth/bcm203x.c
> > index e667933c3d70..547d35425d70 100644
> > --- a/drivers/bluetooth/bcm203x.c
> > +++ b/drivers/bluetooth/bcm203x.c
> > @@ -166,7 +166,7 @@ static int bcm203x_probe(struct usb_interface *intf, const struct usb_device_id
> > if (!data)
> > return -ENOMEM;
> >
> > - data->udev = udev;
> > + data->udev = usb_get_dev(udev);
> > data->state = BCM203X_LOAD_MINIDRV;
> >
> > data->urb = usb_alloc_urb(0, GFP_KERNEL);
> > @@ -244,6 +244,8 @@ static void bcm203x_disconnect(struct usb_interface *intf)
> >
> > usb_set_intfdata(intf, NULL);
> >
> > + usb_put_dev(data->udev);
> > +
> > usb_free_urb(data->urb);
> > kfree(data->fw_data);
> > kfree(data->buffer);
>
> I do not understand this. If this is something broken, then it is broken in
> btusb.c as well and that driver is heavily used by all sorts of devices. So
> we should have seen bug reports about this.
>
> Regards
>
> Marcel
>
Hi Marcel,
The patch is based on the following documentation of usb_get_dev():
[quote]
Each live reference to a device should be refcounted.
Drivers for USB interfaces should normally record such references in their
probe() methods, when they bind to an interface, and release them by calling
usb_put_dev(), in their disconnect() methods.
[/quote]
Regards
Salah
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] bluetooth: bcm203x: update the reference count of udev
2021-08-02 19:34 ` Salah Triki
@ 2021-08-02 20:16 ` Alan Stern
0 siblings, 0 replies; 5+ messages in thread
From: Alan Stern @ 2021-08-02 20:16 UTC (permalink / raw)
To: Salah Triki
Cc: Marcel Holtmann, Johan Hedberg, Luiz Augusto von Dentz,
Greg Kroah-Hartman, open list, Oliver Neukum
On Mon, Aug 02, 2021 at 08:34:11PM +0100, Salah Triki wrote:
> On Sun, Aug 01, 2021 at 08:01:06PM +0200, Marcel Holtmann wrote:
> > Hi Salah,
> >
> > > Use usb_get_dev() to increment the reference count of the usb device
> > > structure in order to avoid releasing the structure while it is still in
> > > use. And use usb_put_dev() to decrement the reference count and thus,
> > > when it will be equal to 0 the structure will be released.
> > >
> > > Signed-off-by: Salah Triki <salah.triki@gmail.com>
> > > ---
> > > Change since v1:
> > > Modification of the description
> > >
> > > drivers/bluetooth/bcm203x.c | 4 +++-
> > > 1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/bluetooth/bcm203x.c b/drivers/bluetooth/bcm203x.c
> > > index e667933c3d70..547d35425d70 100644
> > > --- a/drivers/bluetooth/bcm203x.c
> > > +++ b/drivers/bluetooth/bcm203x.c
> > > @@ -166,7 +166,7 @@ static int bcm203x_probe(struct usb_interface *intf, const struct usb_device_id
> > > if (!data)
> > > return -ENOMEM;
> > >
> > > - data->udev = udev;
> > > + data->udev = usb_get_dev(udev);
> > > data->state = BCM203X_LOAD_MINIDRV;
> > >
> > > data->urb = usb_alloc_urb(0, GFP_KERNEL);
> > > @@ -244,6 +244,8 @@ static void bcm203x_disconnect(struct usb_interface *intf)
> > >
> > > usb_set_intfdata(intf, NULL);
> > >
> > > + usb_put_dev(data->udev);
> > > +
> > > usb_free_urb(data->urb);
> > > kfree(data->fw_data);
> > > kfree(data->buffer);
> >
> > I do not understand this. If this is something broken, then it is broken in
> > btusb.c as well and that driver is heavily used by all sorts of devices. So
> > we should have seen bug reports about this.
> >
> > Regards
> >
> > Marcel
> >
> Hi Marcel,
>
> The patch is based on the following documentation of usb_get_dev():
>
> [quote]
> Each live reference to a device should be refcounted.
>
> Drivers for USB interfaces should normally record such references in their
> probe() methods, when they bind to an interface, and release them by calling
> usb_put_dev(), in their disconnect() methods.
> [/quote]
That documentation is incorrect. It is not necessary for drivers to
take a reference to the devices they are bound to. Properly written
subsystems will guarantee that the driver is unbound from the device
before the device is released.
To put it another way, if failure to take such a reference leads to an
invalid memory access then there is a bug in the subsystem, not in the
driver.
Rather than changing the bcm203x driver, you should consider getting rid
of the unnecessary advice in the documentation of usb_get_dev.
Alan Stern
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-08-02 20:16 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-31 15:41 [PATCH v2] bluetooth: bcm203x: update the reference count of udev Salah Triki
2021-07-31 16:10 ` [v2] " bluez.test.bot
2021-08-01 18:01 ` [PATCH v2] " Marcel Holtmann
2021-08-02 19:34 ` Salah Triki
2021-08-02 20:16 ` Alan Stern
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