All of lore.kernel.org
 help / color / mirror / Atom feed
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.

  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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.