From e33f9a169747880a008dd5e7b934fc592e91cd63 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Thu, 12 Dec 2019 01:07:09 +0100 Subject: [PATCH] kcsan: Add __no_kcsan function attribute Since the use of -fsanitize=thread is an implementation detail of KCSAN, the name __no_sanitize_thread could be misleading if used widely. Instead, we introduce the __no_kcsan attribute which is shorter and more accurate in the context of KCSAN. This matches the attribute name __no_kcsan_or_inline. The use of __kcsan_or_inline itself is still required for __always_inline functions to retain compatibility with older compilers. Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney --- include/linux/compiler-gcc.h | 3 +-- include/linux/compiler.h | 7 +++++-- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 0eb2a1cc411d..cf294faec2f8 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -146,8 +146,7 @@ #endif #if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__) -#define __no_sanitize_thread \ - __attribute__((__noinline__)) __attribute__((no_sanitize_thread)) +#define __no_sanitize_thread __attribute__((no_sanitize_thread)) #else #define __no_sanitize_thread #endif diff --git a/include/linux/compiler.h b/include/linux/compiler.h index ad8c76144a3c..8c0beb10c1dd 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -207,12 +207,15 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, # define __no_kasan_or_inline __always_inline #endif +#define __no_kcsan __no_sanitize_thread #ifdef __SANITIZE_THREAD__ /* * Rely on __SANITIZE_THREAD__ instead of CONFIG_KCSAN, to avoid not inlining in - * compilation units where instrumentation is disabled. + * compilation units where instrumentation is disabled. The attribute 'noinline' + * is required for older compilers, where implicit inlining of very small + * functions renders __no_sanitize_thread ineffective. */ -# define __no_kcsan_or_inline __no_sanitize_thread notrace __maybe_unused +# define __no_kcsan_or_inline __no_kcsan noinline notrace __maybe_unused # define __no_sanitize_or_inline __no_kcsan_or_inline #else # define __no_kcsan_or_inline __always_inline