public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: David Howells <dhowells@redhat.com>,
	linux-kernel@vger.kernel.org, Will Deacon <will.deacon@arm.com>
Subject: Re: [PATCH] iov_iter: Fix 9p virtio breakage
Date: Fri, 2 Nov 2018 19:04:33 +0000	[thread overview]
Message-ID: <20181102190433.GZ32577@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20181102171651.97671-1-marc.zyngier@arm.com>

On Fri, Nov 02, 2018 at 05:16:51PM +0000, Marc Zyngier wrote:
> When switching to the new iovec accessors, a negation got subtly
> dropped, leading to 9p being remarkably broken (here with kvmtool):
> 
> [    7.430941] VFS: Mounted root (9p filesystem) on device 0:15.
> [    7.432080] devtmpfs: mounted
> [    7.432717] Freeing unused kernel memory: 1344K
> [    7.433658] Run /virt/init as init process
>   Warning: unable to translate guest address 0x7e00902ff000 to host
>   Warning: unable to translate guest address 0x7e00902fefc0 to host
>   Warning: unable to translate guest address 0x7e00902ff000 to host
>   Warning: unable to translate guest address 0x7e008febef80 to host
>   Warning: unable to translate guest address 0x7e008febf000 to host
>   Warning: unable to translate guest address 0x7e008febef00 to host
>   Warning: unable to translate guest address 0x7e008febf000 to host
> [    7.436376] Kernel panic - not syncing: Requested init /virt/init failed (error -8).
> [    7.437554] CPU: 29 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc8-02267-g00e23707442a #291
> [    7.439006] Hardware name: linux,dummy-virt (DT)
> [    7.439902] Call trace:
> [    7.440387]  dump_backtrace+0x0/0x148
> [    7.441104]  show_stack+0x14/0x20
> [    7.441768]  dump_stack+0x90/0xb4
> [    7.442425]  panic+0x120/0x27c
> [    7.443036]  kernel_init+0xa4/0x100
> [    7.443725]  ret_from_fork+0x10/0x18
> [    7.444444] SMP: stopping secondary CPUs
> [    7.445391] Kernel Offset: disabled
> [    7.446169] CPU features: 0x0,23000438
> [    7.446974] Memory Limit: none
> [    7.447645] ---[ end Kernel panic - not syncing: Requested init /virt/init failed (error -8). ]---
> 
> Restoring the missing "!" brings the guest back to life.
> 
> Fixes: 00e23707442a ("iov_iter: Use accessor function")
> Reported-by: Will Deacon <will.deacon@arm.com>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

ACK.  Do you want me to take it via vfs.git?  Or might as well
send directly to Linus, with

Acked-by Al Viro <viro@zeniv.linux.org.uk>

on it.

  reply	other threads:[~2018-11-02 19:04 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-02 17:16 [PATCH] iov_iter: Fix 9p virtio breakage Marc Zyngier
2018-11-02 19:04 ` Al Viro [this message]
2018-11-03 10:19   ` Marc Zyngier

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=20181102190433.GZ32577@ZenIV.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=dhowells@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=marc.zyngier@arm.com \
    --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