Re: [PATCH v2 0/3] no_profile fn attr and Kconfig for GCOV+PGO

[Kees Cook]

On Mon, 21 Jun 2021 16:18:19 -0700, Nick Desaulniers wrote:
> The kernel has been using noinstr for correctness to politely request
> that the compiler avoid adding various forms of instrumentation to
> certain functions.
> 
> GCOV and PGO can both instrument functions, yet the function attribute
> to disable such instrumentation (no_profile_instrument_function) was not
> being used to suppress such implementation. Also, clang only just
> recently gained support for no_profile_instrument_function. GCC has
> supported that since 7.1+.
> 
> [...]

Applied to for-next/clang/features, thanks!

[1/3] compiler_attributes.h: define __no_profile, add to noinstr
      https://git.kernel.org/kees/c/380d53c45ff2
[2/3] compiler_attributes.h: cleanups for GCC 4.9+
      https://git.kernel.org/kees/c/ae4d682dfd33
[3/3] Kconfig: add ARCH_WANTS_NO_INSTR+CC_HAS_NO_PROFILE_FN_ATTR, depend on for GCOV and PGO
      https://git.kernel.org/kees/c/51c2ee6d121c

Note that I've tweaked the series slightly to move the PGO Kconfig change into
the PGO patch.

-- 
Kees Cook