[PATCH -tip 08/10] READ_ONCE, WRITE_ONCE: Remove data_race() wrapping

From: Marco Elver
Date: Fri May 15 2020 - 11:04:09 EST


The volatile access no longer needs to be wrapped in data_race(),
because we require compilers that emit instrumentation distinguishing
volatile accesses.

Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
---
include/linux/compiler.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 17c98b215572..fce56402c082 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -229,7 +229,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
#define __READ_ONCE_SCALAR(x) \
({ \
typeof(x) *__xp = &(x); \
- __unqual_scalar_typeof(x) __x = data_race(__READ_ONCE(*__xp)); \
+ __unqual_scalar_typeof(x) __x = __READ_ONCE(*__xp); \
kcsan_check_atomic_read(__xp, sizeof(*__xp)); \
smp_read_barrier_depends(); \
(typeof(x))__x; \
@@ -250,7 +250,7 @@ do { \
do { \
typeof(x) *__xp = &(x); \
kcsan_check_atomic_write(__xp, sizeof(*__xp)); \
- data_race(({ __WRITE_ONCE(*__xp, val); 0; })); \
+ __WRITE_ONCE(*__xp, val); \
} while (0)

#define WRITE_ONCE(x, val) \
--
2.26.2.761.g0e0b3e54be-goog