Re: [syzbot] riscv/fixes boot error: can't ssh into the instance

From: Alexandre Ghiti <alex@ghiti.fr>
To: Dmitry Vyukov <dvyukov@google.com>,
	Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: Aleksandr Nogikh <nogikh@google.com>,
	linux-riscv@lists.infradead.org,
	kasan-dev <kasan-dev@googlegroups.com>,
	palmer@dabbelt.com,
	syzbot <syzbot+330a558d94b58f7601be@syzkaller.appspotmail.com>,
	LKML <linux-kernel@vger.kernel.org>,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] riscv/fixes boot error: can't ssh into the instance
Date: Wed, 16 Feb 2022 05:14:48 +0100	[thread overview]
Message-ID: <a0769218-c84a-a1d3-71e7-aefd40bf54fe@ghiti.fr> (raw)
In-Reply-To: <CACT4Y+arufrRgwmN66wUU+_FGxMy-sTkjMQnRN8U2H2tQuhB7A@mail.gmail.com>

Hi Dmitry,

On 2/15/22 18:12, Dmitry Vyukov wrote:
> On Wed, 2 Feb 2022 at 14:18, Alexandre Ghiti
> <alexandre.ghiti@canonical.com> wrote:
>> Hi Aleksandr,
>>
>> On Wed, Feb 2, 2022 at 12:08 PM Aleksandr Nogikh <nogikh@google.com> wrote:
>>> Hello,
>>>
>>> syzbot has already not been able to fuzz its RISC-V instance for 97
>> That's a longtime, I'll take a look more regularly.
>>
>>> days now because the compiled kernel cannot boot. I bisected the issue
>>> to the following commit:
>>>
>>> commit 54c5639d8f507ebefa814f574cb6f763033a72a5
>>> Author: Alexandre Ghiti <alexandre.ghiti@canonical.com>
>>> Date:   Fri Oct 29 06:59:27 2021 +0200
>>>
>>>      riscv: Fix asan-stack clang build
>>>
>>> Apparently, the problem appears on GCC-built RISC-V kernels with KASAN
>>> enabled. In the previous message syzbot mentions
>>> "riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU
>>> Binutils for Debian) 2.35.2", but the issue also reproduces finely on
>>> a newer GCC compiler: "riscv64-linux-gnu-gcc (Debian 11.2.0-10)
>>> 11.2.0, GNU ld (GNU Binutils for Debian) 2.37".
>>> For convenience, I also duplicate the .config file from the bot's
>>> message: https://syzkaller.appspot.com/x/.config?x=522544a2e0ef2a7d
>>>
>>> Can someone with KASAN and RISC-V expertise please take a look?
>> I'll take a look at that today.
>>
>> Thanks for reporting the issue,
>

I took a quick look, not enough to fix it but I know the issue comes 
from the inline instrumentation, I have no problem with the outline 
instrumentation. I need to find some cycles to work on this, my goal is 
to fix this for 5.17.

Sorry about the delay,

Alex

>
>
>>> --
>>> Best Regards,
>>> Aleksandr
>>>
>>>
>>> On Tue, Jan 18, 2022 at 11:26 AM syzbot
>>> <syzbot+330a558d94b58f7601be@syzkaller.appspotmail.com> wrote:
>>>> Hello,
>>>>
>>>> syzbot found the following issue on:
>>>>
>>>> HEAD commit:    f6f7fbb89bf8 riscv: dts: sifive unmatched: Link the tmp451..
>>>> git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git fixes
>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1095f85bb00000
>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=522544a2e0ef2a7d
>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=330a558d94b58f7601be
>>>> compiler:       riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>>>> userspace arch: riscv64
>>>>
>>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>>> Reported-by: syzbot+330a558d94b58f7601be@syzkaller.appspotmail.com
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