[PATCH 1/2] selftests/openat2: Run-time check for -fsanitize=undefined

["Björn Töpel" <bjorn@kernel.org>]

From: Björn Töpel <bjorn@rivosinc.com>

Some architectures, e.g. riscv, does not have support for the GCC
option '-fsanitize=undefined'.

Check for '-fsanitize=undefined' support, and only add it to CFLAGS if
supported.

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
---
 tools/testing/selftests/openat2/Makefile | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/openat2/Makefile b/tools/testing/selftests/openat2/Makefile
index 843ba56d8e49..f13ad02a18ea 100644
--- a/tools/testing/selftests/openat2/Makefile
+++ b/tools/testing/selftests/openat2/Makefile
@@ -1,6 +1,13 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined
+# We need this for the "try-run" macro.
+include ../../../build/Build.include
+
+CFLAGS += -Wall -O2 -g -fsanitize=address
+CFLAGS += $(call try-run, \
+	echo 'int main() {}' | $(CC) -fsanitize=undefined -x c - -o /dev/null, \
+	-fsanitize=undefined,)
+
 TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test
 
 include ../lib.mk
-- 
2.39.2