From: Qian Cai <cai@lca.pw>
To: Arnd Bergmann <arnd@arndb.de>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <michal.lkml@markovi.net>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Mark Brown <broonie@kernel.org>,
Alexander Potapenko <glider@google.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Christoph Lameter <cl@linux.com>,
Andrey Konovalov <andreyknvl@google.com>,
linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org,
kasan-dev@googlegroups.com
Subject: Re: [PATCH] kasan: turn off asan-stack for clang-8 and earlier
Date: Tue, 19 Feb 2019 17:17:44 -0500 [thread overview]
Message-ID: <1550614664.6911.45.camel@lca.pw> (raw)
In-Reply-To: <20190219214940.391081-1-arnd@arndb.de>
On Tue, 2019-02-19 at 22:49 +0100, Arnd Bergmann wrote:
> Building an arm64 allmodconfig kernel with clang results in over 140 warnings
> about overly large stack frames, the worst ones being:
>
> drivers/gpu/drm/panel/panel-sitronix-st7789v.c:196:12: error: stack frame size
> of 20224 bytes in function 'st7789v_prepare'
> drivers/video/fbdev/omap2/omapfb/displays/panel-tpo-td028ttec1.c:196:12:
> error: stack frame size of 13120 bytes in function 'td028ttec1_panel_enable'
> drivers/usb/host/max3421-hcd.c:1395:1: error: stack frame size of 10048 bytes
> in function 'max3421_spi_thread'
> drivers/net/wan/slic_ds26522.c:209:12: error: stack frame size of 9664 bytes
> in function 'slic_ds26522_probe'
> drivers/crypto/ccp/ccp-ops.c:2434:5: error: stack frame size of 8832 bytes in
> function 'ccp_run_cmd'
> drivers/media/dvb-frontends/stv0367.c:1005:12: error: stack frame size of 7840
> bytes in function 'stv0367ter_algo'
>
> None of these happen with gcc today, and almost all of these are the result
> of a single known bug in llvm. Hopefully it will eventually get fixed with
> the
> clang-9 release.
>
> In the meantime, the best idea I have is to turn off asan-stack for clang-8
> and earlier, so we can produce a kernel that is safe to run.
>
> I have posted three patches that address the frame overflow warnings that are
> not addressed by turning off asan-stack, so in combination with this change,
> we get much closer to a clean allmodconfig build, which in turn is necessary
> to do meaningful build regression testing.
Well, I am using clang 8.0 on arm64 and running the kernel just fine for a few
weeks now and never trigger a single stack overflow (THREAD_SHIFT = 15) because
I never use any of those drivers you mentioned above. I don't think it is a good
idea to blankly remove the testing coverage here and affect people don't use all
those offensive functions at all.
next prev parent reply other threads:[~2019-02-19 22:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-19 21:49 [PATCH] kasan: turn off asan-stack for clang-8 and earlier Arnd Bergmann
2019-02-19 22:17 ` Qian Cai [this message]
2019-02-19 22:43 ` Nick Desaulniers
2019-02-20 0:33 ` Kostya Serebryany
2019-02-20 1:25 ` Qian Cai
2019-02-20 6:44 ` Dmitry Vyukov
2019-02-20 9:19 ` Arnd Bergmann
2019-02-20 14:44 ` Andrey Konovalov
2019-02-20 14:51 ` Arnd Bergmann
2019-02-20 17:00 ` Andrey Ryabinin
2019-02-20 17:35 ` Arnd Bergmann
2019-02-20 18:07 ` Nick Desaulniers
2019-02-20 18:44 ` Mark Brown
2019-02-20 20:02 ` Nick Desaulniers
2019-02-20 21:13 ` Arnd Bergmann
2019-02-20 21:40 ` Arnd Bergmann
2019-02-20 22:12 ` Kostya Serebryany
2019-02-20 23:46 ` Kostya Serebryany
2019-02-21 17:19 ` Arnd Bergmann
2019-02-21 10:06 ` Andrey Ryabinin
2019-02-21 15:19 ` Arnd Bergmann
2019-02-21 16:14 ` Andrey Ryabinin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1550614664.6911.45.camel@lca.pw \
--to=cai@lca.pw \
--cc=akpm@linux-foundation.org \
--cc=andreyknvl@google.com \
--cc=arnd@arndb.de \
--cc=aryabinin@virtuozzo.com \
--cc=broonie@kernel.org \
--cc=cl@linux.com \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-kbuild@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=michal.lkml@markovi.net \
--cc=ndesaulniers@google.com \
--cc=schwidefsky@de.ibm.com \
--cc=yamada.masahiro@socionext.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox