[PATCH] kasan: add no_sanitize attribute for clang builds

[Andrey Konovalov]

KASAN uses the __no_sanitize_address macro to disable instrumentation
of particular functions. Right now it's defined only for GCC build,
which causes false positives when clang is used.

This patch adds a definition for clang.

Note, that clang's revision 329612 or higher is required.

Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
 include/linux/compiler-clang.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index ceb96ecab96e..5a1d8580febe 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -25,6 +25,11 @@
 #define __SANITIZE_ADDRESS__
 #endif
 
+#ifdef CONFIG_KASAN
+#undef __no_sanitize_address
+#define __no_sanitize_address __attribute__((no_sanitize("address")))
+#endif
+
 /* Clang doesn't have a way to turn it off per-function, yet. */
 #ifdef __noretpoline
 #undef __noretpoline
-- 
2.17.0.484.g0c8726318c-goog