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. Alan Stern > include/uapi/linux/usb/raw_gadget.h | 164 ++++ > 6 files changed, 1386 insertions(+) > create mode 100644 Documentation/usb/raw-gadget.rst > create mode 100644 drivers/usb/gadget/raw.c > create mode 100644 include/uapi/linux/usb/raw_gadget.h
