noinstr implies that we would like the compiler to avoid instrumenting a function. Add support for the compiler attribute no_profile_instrument_function to compiler_attributes.h, then add __no_profile to the definition of noinstr. Link: https://lore.kernel.org/lkml/20210614162018.GD68749@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ Link: https://reviews.llvm.org/D104257 Link: https://reviews.llvm.org/D104475 Link: https://reviews.llvm.org/D104658 Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80223 Reviewed-by: Fangrui Song <maskray@xxxxxxxxxx> Reviewed-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> --- Changes V1 -> V2: * s/no_profile/no_profile_instrument_function/ * fix trailing double underscore on GCC 4 define, as per Fangrui+Miguel. * Pick up Fangrui + Miguel's reviewed-by tag. * Add link to GCC's doc. * Fix clang's doc format; will appear once clang-13 is released. include/linux/compiler_attributes.h | 13 +++++++++++++ include/linux/compiler_types.h | 2 +- 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index c043b8d2b17b..225511b17223 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -33,6 +33,7 @@ # define __GCC4_has_attribute___externally_visible__ 1 # define __GCC4_has_attribute___no_caller_saved_registers__ 0 # define __GCC4_has_attribute___noclone__ 1 +# define __GCC4_has_attribute___no_profile_instrument_function__ 0 # define __GCC4_has_attribute___nonstring__ 0 # define __GCC4_has_attribute___no_sanitize_address__ (__GNUC_MINOR__ >= 8) # define __GCC4_has_attribute___no_sanitize_undefined__ (__GNUC_MINOR__ >= 9) @@ -237,6 +238,18 @@ # define __nonstring #endif +/* + * Optional: only supported since GCC >= 7.1, clang >= 13.0. + * + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fprofile_005finstrument_005ffunction-function-attribute + * clang: https://clang.llvm.org/docs/AttributeReference.html#no-profile-instrument-function + */ +#if __has_attribute(__no_profile_instrument_function__) +# define __no_profile __attribute__((__no_profile_instrument_function__)) +#else +# define __no_profile +#endif + /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noreturn-function-attribute * clang: https://clang.llvm.org/docs/AttributeReference.html#noreturn diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index d29bda7f6ebd..d509169860f1 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -210,7 +210,7 @@ struct ftrace_likely_data { /* Section for code which can't be instrumented at all */ #define noinstr \ noinline notrace __attribute((__section__(".noinstr.text"))) \ - __no_kcsan __no_sanitize_address + __no_kcsan __no_sanitize_address __no_profile #endif /* __KERNEL__ */ -- 2.32.0.288.g62a8d224e6-goog
