On Fri, May 31, 2024, at 10:52, Masahiro Yamada wrote: > On Tue, May 28, 2024 at 8:36 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: >> I don't understand the nature of this warning, but I see >> that your patch ended up dropping -fsanitize=kernel-address >> from the compiler flags because the lib/test_fortify/*.c files >> don't match the $(is-kernel-object) rule. Adding back >> -fsanitize=kernel-address shuts up these warnings. > > > In my understanding, fortify-string is independent of KASAN. > > I do not understand why -fsanitize=kernel-address matters. Right, this is something I've failed to understand as well so far. >> I've applied a local workaround in my randconfig tree >> >> diff --git a/lib/Makefile b/lib/Makefile >> index ddcb76b294b5..d7b8fab64068 100644 >> --- a/lib/Makefile >> +++ b/lib/Makefile >> @@ -425,5 +425,7 @@ $(obj)/$(TEST_FORTIFY_LOG): $(addprefix $(obj)/, $(TEST_FORTIFY_LOGS)) FORCE >> >> # Fake dependency to trigger the fortify tests. >> ifeq ($(CONFIG_FORTIFY_SOURCE),y) >> +ifndef CONFIG_KASAN >> $(obj)/string.o: $(obj)/$(TEST_FORTIFY_LOG) >> +endif >> endif >> >> >> which I don't think we want upstream. Can you and Kees come >> up with a proper fix instead? > > I set CONFIG_FORTIFY_SOURCE=y and CONFIG_KASAN=y, > but I did not observe such warnings. > Is this arch or compiler-specific? > > > Could you provide me with the steps to reproduce it? This is a randconfig .config file that shows it, but I've seen it in a lot of others: https://pastebin.com/raw/ESVzUeth If this doesn't reproduce it for you, I can try to narrow it down further. Arnd
