Re: [PATCH] trace: skip hwasan

[Andrey Konovalov]

On Sun, Feb 17, 2019 at 5:34 AM Qian Cai <cai@xxxxxx> wrote:
>
> Enabling function tracer with CONFIG_KASAN_SW_TAGS=y (hwasan) tracer
> causes the whole system frozen on ThunderX2 systems with 256 CPUs,
> because there is a burst of too much pointer access, and then KASAN will
> dereference each byte of the shadow address for the tag checking which
> will kill all the CPUs.

Hi Qian,

Could you check if adding "CFLAGS_REMOVE_tags.o = -pg" into
mm/kasan/Makefile helps with that?

Thanks!

>
> Signed-off-by: Qian Cai <cai@xxxxxx>
> ---
>  kernel/trace/Makefile | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
> index c2b2148bb1d2..fdd547a68385 100644
> --- a/kernel/trace/Makefile
> +++ b/kernel/trace/Makefile
> @@ -28,6 +28,11 @@ ifdef CONFIG_GCOV_PROFILE_FTRACE
>  GCOV_PROFILE := y
>  endif
>
> +# Too much pointer access will kill hwasan.
> +ifdef CONFIG_KASAN_SW_TAGS
> +KASAN_SANITIZE := n
> +endif
> +
>  CFLAGS_trace_benchmark.o := -I$(src)
>  CFLAGS_trace_events_filter.o := -I$(src)
>
> --
> 2.17.2 (Apple Git-113)
>