[PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[Kai-Heng Feng]

Commit 71f6fa90a353 ("HID: increase maximum global item tag report size
to 256") increases the max report size from 128 to 256.

We also need to update the report size in hid_field_extract() otherwise
it complains and truncates now valid report size:
[ 406.165461] hid-sensor-hub 001F:8086:22D8.0002: hid_field_extract() called with n (192) > 32! (kworker/5:1)

BugLink: https://bugs.launchpad.net/bugs/1818547
Fixes: 71f6fa90a353 ("HID: increase maximum global item tag report size to 256")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/hid/hid-core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 9993b692598f..860e21ec6a49 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1301,10 +1301,10 @@ static u32 __extract(u8 *report, unsigned offset, int n)
 u32 hid_field_extract(const struct hid_device *hid, u8 *report,
 			unsigned offset, unsigned n)
 {
-	if (n > 32) {
-		hid_warn(hid, "hid_field_extract() called with n (%d) > 32! (%s)\n",
+	if (n > 256) {
+		hid_warn(hid, "hid_field_extract() called with n (%d) > 256! (%s)\n",
 			 n, current->comm);
-		n = 32;
+		n = 256;
 	}
 
 	return __extract(report, offset, n);
-- 
2.17.1

Re: [PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[Jiri Kosina]

On Fri, 8 Mar 2019, Kai-Heng Feng wrote:

> Commit 71f6fa90a353 ("HID: increase maximum global item tag report size
> to 256") increases the max report size from 128 to 256.
> 
> We also need to update the report size in hid_field_extract() otherwise
> it complains and truncates now valid report size:
> [ 406.165461] hid-sensor-hub 001F:8086:22D8.0002: hid_field_extract() called with n (192) > 32! (kworker/5:1)
> 
> BugLink: https://bugs.launchpad.net/bugs/1818547
> Fixes: 71f6fa90a353 ("HID: increase maximum global item tag report size to 256")
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Applied, thanks.

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[Benjamin Tissoires]

Hi,


On Fri, Mar 8, 2019 at 6:11 AM Kai-Heng Feng
<kai.heng.feng@canonical.com> wrote:
>
> Commit 71f6fa90a353 ("HID: increase maximum global item tag report size
> to 256") increases the max report size from 128 to 256.
>
> We also need to update the report size in hid_field_extract() otherwise
> it complains and truncates now valid report size:
> [ 406.165461] hid-sensor-hub 001F:8086:22D8.0002: hid_field_extract() called with n (192) > 32! (kworker/5:1)
>
> BugLink: https://bugs.launchpad.net/bugs/1818547
> Fixes: 71f6fa90a353 ("HID: increase maximum global item tag report size to 256")
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
>  drivers/hid/hid-core.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> index 9993b692598f..860e21ec6a49 100644
> --- a/drivers/hid/hid-core.c
> +++ b/drivers/hid/hid-core.c
> @@ -1301,10 +1301,10 @@ static u32 __extract(u8 *report, unsigned offset, int n)
>  u32 hid_field_extract(const struct hid_device *hid, u8 *report,
>                         unsigned offset, unsigned n)

Ronald (Cc-ed) raised quite a good point:
what's the benefit of removing the error message if this function (and
__extract) can only report an unsigned 32 bits value?

My take is we should revert 94a9992f7dbdfb28976b upstream and think at
a better solution.

Cheers,
Benjamin

>  {
> -       if (n > 32) {
> -               hid_warn(hid, "hid_field_extract() called with n (%d) > 32! (%s)\n",
> +       if (n > 256) {
> +               hid_warn(hid, "hid_field_extract() called with n (%d) > 256! (%s)\n",
>                          n, current->comm);
> -               n = 32;
> +               n = 256;
>         }
>
>         return __extract(report, offset, n);
> --
> 2.17.1
>

Re: [PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[Kai-Heng Feng]

at 17:42, Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote:

> Hi,
>
>
> On Fri, Mar 8, 2019 at 6:11 AM Kai-Heng Feng
> <kai.heng.feng@canonical.com> wrote:
>> Commit 71f6fa90a353 ("HID: increase maximum global item tag report size
>> to 256") increases the max report size from 128 to 256.
>>
>> We also need to update the report size in hid_field_extract() otherwise
>> it complains and truncates now valid report size:
>> [ 406.165461] hid-sensor-hub 001F:8086:22D8.0002: hid_field_extract()  
>> called with n (192) > 32! (kworker/5:1)
>>
>> BugLink: https://bugs.launchpad.net/bugs/1818547
>> Fixes: 71f6fa90a353 ("HID: increase maximum global item tag report size  
>> to 256")
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>> ---
>>  drivers/hid/hid-core.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
>> index 9993b692598f..860e21ec6a49 100644
>> --- a/drivers/hid/hid-core.c
>> +++ b/drivers/hid/hid-core.c
>> @@ -1301,10 +1301,10 @@ static u32 __extract(u8 *report, unsigned  
>> offset, int n)
>>  u32 hid_field_extract(const struct hid_device *hid, u8 *report,
>>                         unsigned offset, unsigned n)
>
> Ronald (Cc-ed) raised quite a good point:
> what's the benefit of removing the error message if this function (and
> __extract) can only report an unsigned 32 bits value?

I didn’t spot this, sorry.

>
> My take is we should revert 94a9992f7dbdfb28976b upstream and think at
> a better solution.

I think using a new fix to replace it will be a better approach, as it at  
least partially solves the issue.

Kai-Heng

>
> Cheers,
> Benjamin
>
>> {
>> -       if (n > 32) {
>> -               hid_warn(hid, "hid_field_extract() called with n (%d) >  
>> 32! (%s)\n",
>> +       if (n > 256) {
>> +               hid_warn(hid, "hid_field_extract() called with n (%d) >  
>> 256! (%s)\n",
>>                          n, current->comm);
>> -               n = 32;
>> +               n = 256;
>>         }
>>
>>         return __extract(report, offset, n);
>> —

>> 2.17.1

Re: [PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[Jiri Kosina]

On Fri, 26 Apr 2019, Kai-Heng Feng wrote:

> >Ronald (Cc-ed) raised quite a good point:
> >what's the benefit of removing the error message if this function (and
> >__extract) can only report an unsigned 32 bits value?
> 
> I didn’t spot this, sorry.
> 
> >
> >My take is we should revert 94a9992f7dbdfb28976b upstream and think at
> >a better solution.
> 
> I think using a new fix to replace it will be a better approach, as it at
> least partially solves the issue.

Guys, did this fall in between cracks? Is anyone planning to send a fixup?

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[Benjamin Tissoires]

On Thu, May 9, 2019 at 9:30 PM Jiri Kosina <jikos@kernel.org> wrote:
>
> On Fri, 26 Apr 2019, Kai-Heng Feng wrote:
>
> > >Ronald (Cc-ed) raised quite a good point:
> > >what's the benefit of removing the error message if this function (and
> > >__extract) can only report an unsigned 32 bits value?
> >
> > I didn’t spot this, sorry.
> >
> > >
> > >My take is we should revert 94a9992f7dbdfb28976b upstream and think at
> > >a better solution.
> >
> > I think using a new fix to replace it will be a better approach, as it at
> > least partially solves the issue.
>
> Guys, did this fall in between cracks? Is anyone planning to send a fixup?
>

Kai-Heng, have you been able to work on that?

Cheers,
Benjamin

Re: [PATCH] HID: Increase maximum report size allowed by hid_field_extract()

[Kai Heng Feng]

> On May 21, 2019, at 9:58 PM, Benjamin Tissoires <benjamin.tissoires@redhat.com> wrote:
> 
> On Thu, May 9, 2019 at 9:30 PM Jiri Kosina <jikos@kernel.org> wrote:
>> 
>> On Fri, 26 Apr 2019, Kai-Heng Feng wrote:
>> 
>>>> Ronald (Cc-ed) raised quite a good point:
>>>> what's the benefit of removing the error message if this function (and
>>>> __extract) can only report an unsigned 32 bits value?
>>> 
>>> I didn’t spot this, sorry.
>>> 
>>>> 
>>>> My take is we should revert 94a9992f7dbdfb28976b upstream and think at
>>>> a better solution.
>>> 
>>> I think using a new fix to replace it will be a better approach, as it at
>>> least partially solves the issue.
>> 
>> Guys, did this fall in between cracks? Is anyone planning to send a fixup?
>> 
> 
> Kai-Heng, have you been able to work on that?

Sorry, I haven’t been able to work on this.

Please revert the commit and possibly use *_once() macro to reduce the noise.

Kai-Heng

> 
> Cheers,
> Benjamin