selftests/nolibc: enable UBSAN if available

UBSAN detects undefined behaviour at runtime.
To avoid introduction of new UB, enable UBSAN for nolibc-test.

By signalling detected errors through traps no runtime dependency
is necessary.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250419-nolibc-ubsan-v2-7-060b8a016917@weissschuh.net

diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index aa05c1faac20d3054b231090b939d050b0231d40..94f3e8be7a68f63ecd639c4f283b3cd10764ce74 100644 (file)
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -189,9 +189,10 @@ ifeq ($(origin XARCH),command line)
 CFLAGS_XARCH = $(CFLAGS_$(XARCH))
 endif
 CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all))
+CFLAGS_SANITIZER ?= $(call cc-option,-fsanitize=undefined -fsanitize-trap=all)
 CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 -W -Wall -Wextra \
                $(call cc-option,-fno-stack-protector) $(call cc-option,-Wmissing-prototypes) \
-               $(CFLAGS_XARCH) $(CFLAGS_STACKPROTECTOR) $(CFLAGS_EXTRA)
+               $(CFLAGS_XARCH) $(CFLAGS_STACKPROTECTOR) $(CFLAGS_SANITIZER) $(CFLAGS_EXTRA)
 LDFLAGS :=
 
 LIBGCC := -lgcc