Re: [syzbot] BUG: soft lockup in do_wp_page (4)

On Thu, Mar 18, 2021 at 08:34:16PM +0100, Dmitry Vyukov wrote:

On Thu, Mar 18, 2021 at 8:31 PM syzbot
[off-list ref] wrote:

quoted

Hello,

syzbot found the following issue on:

HEAD commit:    bf152b0b Merge tag 'for_linus' of git://git.kernel.org/pub..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17d5264ed00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2c9917c41f0bc04b
dashboard link: https://syzkaller.appspot.com/bug?extid=0b036374a865ba0efa8e
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0b036374a865ba0efa8e@syzkaller.appspotmail.com

watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [syz-executor.1:3684]

+Will, arm

If I am reading this commit correctly, this is caused by:

commit cae118b6acc309539b33339e846cbb19187c164c
Author: Will Deacon
Date:   Wed Mar 3 13:49:27 2021 +0000
    arm64: Drop support for CMDLINE_EXTEND

syzbot passes lots of critical things in CONFIG_CMDLINE:
https://github.com/google/syzkaller/blob/c3c81c94865791469d376eba84f4a2d7763d3f71/dashboard/config/linux/upstream-arm64-kasan.config#L495
but also wants the bootloader args to be appended.
What is the way to do it now?

For now, there isn't a way to do it with CONFIG_CMDLINE, so I think you can
either:

  * Revert my patch for your kernels
  * Pass the arguments via QEMU's -append option
  * Take a look at one of the series which should hopefully add this
    functionality back (but with well-defined semantics) [1] [2]

Sorry for the nuisance; I did try to fix this [3] but it's a bit of a
mess.

Will

[1] https://lore.kernel.org/linux-arch/cover.1614705851.git.christophe.leroy@csgroup.eu/ (local)
[2] https://lore.kernel.org/linux-mips/20210308235319.2988609-2-danielwa@cisco.com/#t (local)
[3] https://lore.kernel.org/r/20210225125921.13147-1-will@kernel.org (local)

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel