From: Qian Cai <cai@lca.pw>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
kasan-dev <kasan-dev@googlegroups.com>,
Linux-MM <linux-mm@kvack.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] arm64: increase stack size for KASAN_EXTRA
Date: Tue, 11 Dec 2018 12:18:27 -0500 [thread overview]
Message-ID: <1544548707.18411.3.camel@lca.pw> (raw)
In-Reply-To: <CAK8P3a20kRDrkS1YFLp6cYeKcUoC9s+O_tnYNbKEMWGukia1Tg@mail.gmail.com>
On Tue, 2018-12-11 at 13:42 +0100, Arnd Bergmann wrote:
> On Fri, Dec 7, 2018 at 11:35 PM Qian Cai <cai@lca.pw> wrote:
> >
> > If the kernel is configured with KASAN_EXTRA, the stack size is
> > increasted significantly due to enable this option will set
> > -fstack-reuse to "none" in GCC [1]. As the results, it could trigger
> > stack overrun quite often with 32k stack size compiled using GCC 8. For
> > example, this reproducer
> >
> > size
> > 7536 shrink_inactive_list
> > 7440 shrink_page_list
> > 6560 fscache_stats_show
> > 3920 jbd2_journal_commit_transaction
> > 3216 try_to_unmap_one
> > 3072 migrate_page_move_mapping
> > 3584 migrate_misplaced_transhuge_page
> > 3920 ip_vs_lblcr_schedule
> > 4304 lpfc_nvme_info_show
> > 3888 lpfc_debugfs_nvmestat_data.constprop
> >
> > There are other 49 functions are over 2k in size while compiling kernel
> > with "-Wframe-larger-than=" on this machine. Hence, it is too much work
> > to change Makefiles for each object to compile without
> > -fsanitize-address-use-after-scope individually.
> >
> > [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715#c23
>
> Could you clarify: are the numbers you see with or without the bugfix
> from that bugzilla?
>
The numbers were from GCC8 which does NOT contain this patch [1].
GCC9 is awesome which reduced the numbers in half even for KASAN_EXTRA. Only
thing is that GCC9 has not been officially released yet, so it is a bit
inconvenient for users need to compile the compiler by themselves first.
I am fine either way to drop this patch or keep it until GCC9 is GA.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715#c35
next prev parent reply other threads:[~2018-12-11 17:18 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 4:45 Kernel panic - not syncing: corrupted stack end detected inside scheduler Qian Cai
2018-12-07 22:34 ` [PATCH] arm64: increase stack size for KASAN_EXTRA Qian Cai
2018-12-11 12:42 ` Arnd Bergmann
2018-12-11 17:18 ` Qian Cai [this message]
2018-12-11 21:43 ` Arnd Bergmann
2018-12-11 21:52 ` Qian Cai
2018-12-11 21:56 ` Arnd Bergmann
2018-12-11 21:59 ` Qian Cai
2018-12-11 22:12 ` Arnd Bergmann
2018-12-11 22:22 ` Qian Cai
2018-12-11 23:06 ` Arnd Bergmann
2018-12-12 3:54 ` Qian Cai
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=1544548707.18411.3.camel@lca.pw \
--to=cai@lca.pw \
--cc=arnd@arndb.de \
--cc=aryabinin@virtuozzo.com \
--cc=catalin.marinas@arm.com \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=will.deacon@arm.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;
as well as URLs for NNTP newsgroup(s).