On Mon, Jun 21, 2021 at 04:18:22PM -0700, Nick Desaulniers wrote: > We don't want compiler instrumentation to touch noinstr functions, which > are annotated with the no_profile_instrument_function function > attribute. Add a Kconfig test for this and make PGO and GCOV depend on > it. > > If an architecture is using noinstr, it should denote that via this > Kconfig value. That makes Kconfigs that depend on noinstr able to > express dependencies in an architecturally agnostic way. > > Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx> > Cc: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx> > Link: https://lore.kernel.org/lkml/YMTn9yjuemKFLbws@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > Link: https://lore.kernel.org/lkml/YMcssV%2Fn5IBGv4f0@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > Suggested-by: Nathan Chancellor <nathan@xxxxxxxxxx> > Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > --- > Changes V1 -> V2: > * Add ARCH_WANTS_NO_INSTR > * Change depdendencies to be !ARCH_WANTS_NO_INSTR || CC_HAS_NO_PROFILE_FN_ATTR > rather than list architectures explicitly, as per Nathan. > * s/no_profile/no_profile_instrument_function/ > > arch/Kconfig | 7 +++++++ > arch/arm64/Kconfig | 1 + > arch/s390/Kconfig | 1 + > arch/x86/Kconfig | 1 + > init/Kconfig | 3 +++ > kernel/gcov/Kconfig | 1 + > kernel/pgo/Kconfig | 3 ++- > 7 files changed, 16 insertions(+), 1 deletion(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index 2b4109b0edee..2113c6b3b801 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -285,6 +285,13 @@ config ARCH_THREAD_STACK_ALLOCATOR > config ARCH_WANTS_DYNAMIC_TASK_STRUCT > bool > > +config ARCH_WANTS_NO_INSTR > + bool > + help > + An architecure should select this if the noinstr macro is being used on > + functions to denote that the toolchain should avoid instrumenting such > + functions and is required for correctness. > + > config ARCH_32BIT_OFF_T > bool > depends on !64BIT There's also CC_HAS_WORKING_NOSANITIZE_ADDRESS in lib/Kconfig.kasan that might want to be hooked into this, but that can be done separately I suppose.
