[PATCH v3 24/25] compiler_attributes.h: Add __disable_sanitizer_instrumentation
From: Marco Elver <elver@google.com>
Date: 2021-11-30 11:47:13
Also in:
linux-arch, linux-doc, linux-kbuild, linux-mm, lkml
Subsystem:
compiler attributes, the rest · Maintainers:
Miguel Ojeda, Linus Torvalds
From: Alexander Potapenko <glider@google.com> 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> --- v3: * New patch. --- include/linux/compiler_attributes.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)
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
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2.34.0.rc2.393.gf8c9666880-goog