samples/bpf: Add -fsanitize=bounds to userspace programs

The sanitizer flag, which is supported by both clang and gcc, would make
it easier to debug array index out-of-bounds problems in these programs.

Make the Makfile smarter to detect ubsan support from the compiler and
add the '-fsanitize=bounds' accordingly.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jinghao Jia <jinghao@linux.ibm.com>
Signed-off-by: Jinghao Jia <jinghao7@illinois.edu>
Signed-off-by: Ruowen Qin <ruowenq2@illinois.edu>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230927045030.224548-2-ruowenq2@illinois.edu

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 6c707ebcebb9f1f01eabff67ae8c84b0c100e954..90af76fa9dd8a3049e9170a0f88720599e0ba118 100644 (file)
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -169,6 +169,9 @@ endif
 TPROGS_CFLAGS += -Wall -O2
 TPROGS_CFLAGS += -Wmissing-prototypes
 TPROGS_CFLAGS += -Wstrict-prototypes
+TPROGS_CFLAGS += $(call try-run,\
+       printf "int main() { return 0; }" |\
+       $(CC) -Werror -fsanitize=bounds -x c - -o "$$TMP",-fsanitize=bounds,)
 
 TPROGS_CFLAGS += -I$(objtree)/usr/include
 TPROGS_CFLAGS += -I$(srctree)/tools/testing/selftests/bpf/