Re: [PATCH v2] kasan: disable kasan_strings() kunit test when CONFIG_FORTIFY_SOURCE enabled

[Andrey Konovalov <andreyknvl@gmail.com>]

On Fri, Aug 1, 2025 at 11:28 AM Yeoreum Yun <yeoreum.yun@arm.com> wrote:
>
> When CONFIG_FORTIFY_SOURCE is enabled, invalid access from source
> triggers __fortify_panic() which kills running task.
>
> This makes failured of kasan_strings() kunit testcase since the
> kunit-try-cacth kthread running kasan_string() dies before checking the
> fault.
>
> To address this, add define for __NO_FORTIFY for kasan kunit test.
>
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> ---
>  mm/kasan/Makefile | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile
> index dd93ae8a6beb..b70d76c167ca 100644
> --- a/mm/kasan/Makefile
> +++ b/mm/kasan/Makefile
> @@ -44,6 +44,10 @@ ifndef CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX
>  CFLAGS_KASAN_TEST += -fno-builtin
>  endif
>
> +ifdef CONFIG_FORTIFY_SOURCE
> +CFLAGS_KASAN_TEST += -D__NO_FORTIFY
> +endif

We should be able to use OPTIMIZER_HIDE_VAR() to deal with this
instead; see commits b2325bf860fa and 09c6304e38e4.

> +
>  CFLAGS_REMOVE_kasan_test_c.o += $(call cc-option, -Wvla-larger-than=1)
>  CFLAGS_kasan_test_c.o := $(CFLAGS_KASAN_TEST)
>  RUSTFLAGS_kasan_test_rust.o := $(RUSTFLAGS_KASAN)
> --
> LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
>