It appears that compilers have trouble with nested statements expressions, as such make the data_race() macro be only a single statement expression. This will help us avoid potential problems in future as its usage increases.
Link: https://lkml.kernel.org/r/20200520221712.ga21...@zn.tnic Signed-off-by: Marco Elver <el...@google.com> --- v2: * Add patch to series in response to above linked discussion. --- include/linux/compiler.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 7444f026eead..1f9bd9f35368 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -211,12 +211,11 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, */ #define data_race(expr) \ ({ \ + __unqual_scalar_typeof(({ expr; })) __v; \ __kcsan_disable_current(); \ - ({ \ - __unqual_scalar_typeof(({ expr; })) __v = ({ expr; }); \ - __kcsan_enable_current(); \ - __v; \ - }); \ + __v = ({ expr; }); \ + __kcsan_enable_current(); \ + __v; \ }) /* -- 2.26.2.761.g0e0b3e54be-goog
