Re: [PATCH v3 3/3] HID: core: fix dmesg flooding if report field larger than 32bit

From: Benjamin Tissoires
Date: Wed Sep 18 2019 - 11:35:35 EST


On Thu, Aug 29, 2019 at 1:26 AM Joshua Clayton <stillcompiling@xxxxxxxxx> wrote:
>
> ping?
> I'd love to see this get in.
> with distro kernel I have effectively no dmesg due to this issue

Apologies for the delay.

I really thought we should find a better way of fixing this, until I
got a laptop affected by it. This series is a must have.

Applied to for-5.4/core

Cheers,
Benjamin

>
> On Mon, Aug 12, 2019 at 9:20 AM <stillcompiling@xxxxxxxxx> wrote:
> >
> > From: Joshua Clayton <stillcompiling@xxxxxxxxx>
> >
> > Only warn once of oversize hid report value field
> >
> > On HP spectre x360 convertible the message:
> > hid-sensor-hub 001F:8087:0AC2.0002: hid_field_extract() called with n (192) > 32! (kworker/1:2)
> > is continually printed many times per second, crowding out all else.
> > Protect dmesg by printing the warning only one time.
> >
> > The size of the hid report field data structure should probably be increased.
> > The data structure is treated as a u32 in Linux, but an unlimited number
> > of bits in the USB hid spec, so there is some rearchitecture needed now that
> > devices are sending more than 32 bits.
> >
> > Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx>
> >
> > diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
> > index 210b81a56e1a..3eaee2c37931 100644
> > --- a/drivers/hid/hid-core.c
> > +++ b/drivers/hid/hid-core.c
> > @@ -1311,8 +1311,8 @@ 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",
> > - n, current->comm);
> > + hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
> > + __func__, n, current->comm);
> > n = 32;
> > }
> >
> > --
> > 2.21.0
> >