[PATCH RFC 0/3] kcov: collect coverage from usb and vhost

This patchset extends kcov to allow collecting coverage from the USB
subsystem and vhost workers. See the first patch description for details
about the kcov extension. The other two patches apply this kcov extension
to USB and vhost.

These patches have been used to enable coverage-guided USB fuzzing with
syzkaller for the last few years, see the details here:

https://github.com/google/syzkaller/blob/master/docs/linux/external_fuzzing_usb.md

Andrey Konovalov (3):
  kcov: remote coverage support
  usb, kcov: collect coverage from hub_event
  vhost, kcov: collect coverage from vhost_worker

 Documentation/dev-tools/kcov.rst |  99 +++++++
 drivers/usb/core/hub.c           |   4 +
 drivers/vhost/vhost.c            |  15 ++
 drivers/vhost/vhost.h            |   3 +
 include/linux/kcov.h             |  10 +
 include/linux/sched.h            |   6 +
 include/uapi/linux/kcov.h        |  18 ++
 kernel/kcov.c                    | 434 ++++++++++++++++++++++++++++---
 8 files changed, 554 insertions(+), 35 deletions(-)

-- 
2.23.0.866.gb869b98d4c-goog