We don't want compiler instrumentation to touch noinstr functions, which are annotated with the no_profile function attribute. Add a Kconfig test for this and make PGO and GCOV depend on it. 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: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> --- init/Kconfig | 3 +++ kernel/gcov/Kconfig | 1 + kernel/pgo/Kconfig | 3 ++- 3 files changed, 6 insertions(+), 1 deletion(-) diff --git a/init/Kconfig b/init/Kconfig index 1ea12c64e4c9..540f862b40c6 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -83,6 +83,9 @@ config TOOLS_SUPPORT_RELR config CC_HAS_ASM_INLINE def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null) +config CC_HAS_NO_PROFILE_FN_ATTR + def_bool $(success,echo '__attribute__((no_profile)) int x();' | $(CC) -x c - -c -o /dev/null -Werror) + config CONSTRUCTORS bool diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig index 58f87a3092f3..19facd4289cd 100644 --- a/kernel/gcov/Kconfig +++ b/kernel/gcov/Kconfig @@ -5,6 +5,7 @@ config GCOV_KERNEL bool "Enable gcov-based kernel profiling" depends on DEBUG_FS depends on !CC_IS_CLANG || CLANG_VERSION >= 110000 + depends on !X86 || (X86 && CC_HAS_NO_PROFILE_FN_ATTR) select CONSTRUCTORS default n help diff --git a/kernel/pgo/Kconfig b/kernel/pgo/Kconfig index d2053df1111c..26f75ac4c6c1 100644 --- a/kernel/pgo/Kconfig +++ b/kernel/pgo/Kconfig @@ -8,7 +8,8 @@ config PGO_CLANG bool "Enable clang's PGO-based kernel profiling" depends on DEBUG_FS depends on ARCH_SUPPORTS_PGO_CLANG - depends on CC_IS_CLANG && CLANG_VERSION >= 120000 + depends on CC_IS_CLANG + depends on CC_HAS_NO_PROFILE_FN_ATTR help This option enables clang's PGO (Profile Guided Optimization) based code profiling to better optimize the kernel. -- 2.32.0.288.g62a8d224e6-goog
