0
0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-12-15 23:14:31 +08:00
linux/scripts/Makefile.kcsan
Marco Elver 116af35e38 kcsan: Ignore GCC 11+ warnings about TSan runtime support
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🔢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@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:27 -08:00

27 lines
1004 B
Makefile

# SPDX-License-Identifier: GPL-2.0
# GCC and Clang accept backend options differently. Do not wrap in cc-option,
# because Clang accepts "--param" even if it is unused.
ifdef CONFIG_CC_IS_CLANG
cc-param = -mllvm -$(1)
else
cc-param = --param $(1)
endif
# Keep most options here optional, to allow enabling more compilers if absence
# of some options does not break KCSAN nor causes false positive reports.
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
export CFLAGS_KCSAN := $(kcsan-cflags)