Re: [PATCH 0/1] usb: gadget: add raw-gadget interface

From: Andrey Konovalov
Date: Fri Nov 08 2019 - 17:18:52 EST


On Fri, Nov 8, 2019 at 10:45 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, 8 Nov 2019, Andrey Konovalov wrote:
>
> > This patchset (currently a single patch) adds a new userspace interface
> > for the USB Gadget subsystem called USB Raw Gadget (I don't mind changing
> > the name to something else if there are better ideas). This is what
> > currently being used to enable coverage-buided USB fuzzing with syzkaller:
> >
> > https://github.com/google/syzkaller/blob/master/docs/linux/external_fuzzing_usb.md
> >
> > Initially I was using GadgetFS (together with the Dummy HCD/UDC module)
> > to perform emulation of USB devices for fuzzing, but later switched to a
> > custom written interface. The incentive to implement a different interface
> > was to provide a somewhat raw and direct access to the USB Gadget layer
> > for the userspace, where every USB request is passed to the userspace to
> > get a response. See documentation for the list of differences between
> > Raw Gadget and GadgetFS.
> >
> > This patchset has been pushed to the public Linux kernel Gerrit instance:
> >
> > https://linux-review.googlesource.com/c/linux/kernel/git/torvalds/linux/+/2144
> >
> > Andrey Konovalov (1):
> > usb: gadget: add raw-gadget interface
> >
> > Documentation/usb/index.rst | 1 +
> > Documentation/usb/raw-gadget.rst | 60 ++
> > drivers/usb/gadget/Kconfig | 9 +
> > drivers/usb/gadget/Makefile | 2 +
> > drivers/usb/gadget/raw.c | 1150 +++++++++++++++++++++++++++
>
> As a general rule, gadget drivers don't go directly in
> drivers/usb/gadget. raw.c counts as a legacy driver (because it's not
> written to use the composite gadget framework), so it belongs in
> drivers/usb/gadget/legacy. That's where the gadgetfs driver lives, for
> example.

Hi Alan! Sure, I'll move it to legacy/ in v2. Thanks!