On Fri, Jun 17, 2016 at 08:42:28AM -0700, Kees Cook wrote: > On Fri, Jun 17, 2016 at 2:39 AM, Mark Rutland <mark.rutl...@arm.com> wrote: > > If the toolchain does not support -fsanitize-coverage=trace-pc, we blat > > this option from CFLAGS_KCOV, and build the kernel without > > instrumentation, even if CONFIG_KCOV was selected. However, we still > > build the rest of the kcov infrastructure, and expose a kcov file under > > debugfs. This can be confusing, as the kernel will appear to support > > kcov, yet will never manage to sample any trace PC values. While we do > > note this fact at build time, this may be missed, and a user may not > > have access to build logs. > > Do you want to refuse to build if the compiler doesn't support the > flag?
I would also be happy with that, so it's up to Alexander and Dmitry. > I finally figured out how to do this, I think, for > -fstack-protector: > > http://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/commit/?h=kbuild/stackprotector&id=600c1bd5f8647a8470dc2fc5a8697e3eafb5fd52 > > If you wanted, the CONFIG_KCOV test could live under the same > prepare-compiler-check target. Alexander, Dmitry, thoughts? Thanks, Mark.