GCC 11 has introduced a new warning option, -Wtsan [1], to warn about unsupported operations in the TSan runtime. But KCSAN != TSan runtime, so none of the warnings apply. [1] https://gcc.gnu.org/onlinedocs/gcc-11.1.0/gcc/Warning-Options.html Ignore the warnings. Currently the warning only fires in the test for __atomic_thread_fence(): kernel/kcsan/kcsan_test.c: In function ‘test_atomic_builtins’: kernel/kcsan/kcsan_test.c:1234:17: warning: ‘atomic_thread_fence’ is not supported with ‘-fsanitize=thread’ [-Wtsan] 1234 | __atomic_thread_fence(__ATOMIC_SEQ_CST); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ which exists to ensure the KCSAN runtime keeps supporting the builtin instrumentation. Signed-off-by: Marco Elver <elver@xxxxxxxxxx> --- scripts/Makefile.kcsan | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/scripts/Makefile.kcsan b/scripts/Makefile.kcsan index 4c7f0d282e42..19f693b68a96 100644 --- a/scripts/Makefile.kcsan +++ b/scripts/Makefile.kcsan @@ -13,6 +13,12 @@ kcsan-cflags := -fsanitize=thread -fno-optimize-sibling-calls \ $(call cc-option,$(call cc-param,tsan-compound-read-before-write=1),$(call cc-option,$(call cc-param,tsan-instrument-read-before-write=1))) \ $(call cc-param,tsan-distinguish-volatile=1) +ifdef CONFIG_CC_IS_GCC +# GCC started warning about operations unsupported by the TSan runtime. But +# KCSAN != TSan, so just ignore these warnings. +kcsan-cflags += -Wno-tsan +endif + ifndef CONFIG_KCSAN_WEAK_MEMORY kcsan-cflags += $(call cc-option,$(call cc-param,tsan-instrument-func-entry-exit=0)) endif -- 2.34.0.rc2.393.gf8c9666880-goog
