From a015b7085979b12e55f67f3b86be0321fff6be3f Mon Sep 17 00:00:00 2001 From: Alexander Potapenko <glider@google.com> Date: Tue, 30 Nov 2021 12:44:32 +0100 Subject: compiler_attributes.h: Add __disable_sanitizer_instrumentation The new attribute maps to __attribute__((disable_sanitizer_instrumentation)), which will be supported by Clang >= 14.0. Future support in GCC is also possible. This attribute disables compiler instrumentation for kernel sanitizer tools, making it easier to implement noinstr. It is different from the existing __no_sanitize* attributes, which may still allow certain types of instrumentation to prevent false positives. Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- include/linux/compiler_attributes.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/linux/compiler_attributes.h') diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index b9121afd8733..37e260020221 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -308,6 +308,24 @@ # define __compiletime_warning(msg) #endif +/* + * Optional: only supported since clang >= 14.0 + * + * clang: https://clang.llvm.org/docs/AttributeReference.html#disable-sanitizer-instrumentation + * + * disable_sanitizer_instrumentation is not always similar to + * no_sanitize((<sanitizer-name>)): the latter may still let specific sanitizers + * insert code into functions to prevent false positives. Unlike that, + * disable_sanitizer_instrumentation prevents all kinds of instrumentation to + * functions with the attribute. + */ +#if __has_attribute(disable_sanitizer_instrumentation) +# define __disable_sanitizer_instrumentation \ + __attribute__((disable_sanitizer_instrumentation)) +#else +# define __disable_sanitizer_instrumentation +#endif + /* * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-weak-function-attribute * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-weak-variable-attribute -- cgit