linux-kernel - Re: [PATCH] trace: skip hwasan

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190218104359.GB10743@fuggles.cambridge.arm.com>
Date:   Mon, 18 Feb 2019 10:43:59 +0000
From:   Will Deacon <will.deacon@....com>
To:     Qian Cai <cai@....pw>
Cc:     rostedt@...dmis.org, mingo@...hat.com, catalin.marinas@....com,
        andreyknvl@...gle.com, aryabinin@...tuozzo.com,
        linux-arm-kernel@...ts.infradead.org, kasan-dev@...glegroups.com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] trace: skip hwasan

On Sat, Feb 16, 2019 at 11:34:34PM -0500, Qian Cai 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.
> 
> Signed-off-by: Qian Cai <cai@....pw>
> ---
>  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

I don't maintain this file, but I think that my comments on your related
patch are relevant here as well:

https://lkml.org/lkml/2019/2/18/223

Will