All of lore.kernel.org
 help / color / mirror / Atom feed
From: Steven Rostedt <rostedt@goodmis.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Hurley <peter@hurleysoftware.com>,
	Jiri Slaby <jslaby@suse.cz>, Greg KH <gregkh@linuxfoundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	stable <stable@vger.kernel.org>,
	lwn@lwn.net
Subject: Re: BUG: unable to handle kernel paging request from pty_write [was: Linux 4.4.2]
Date: Thu, 25 Feb 2016 14:23:38 -0500	[thread overview]
Message-ID: <20160225142338.42e46f2c@gandalf.local.home> (raw)
In-Reply-To: <CA+55aFyeVmnNuk5pPoH05uPKZRSXt1hv_0PWuvndptqBSfPrbA@mail.gmail.com>

On Thu, 25 Feb 2016 11:09:35 -0800
Linus Torvalds <torvalds@linux-foundation.org> wrote:


> Jiri, were you messing around with tracing when this happened? Or
> maybe shutting down CPU's? There was a RCU locking problem with CPU
> shutdown, maybe this is one of the symptoms. The fix for that is
> recent, and not in 4.4.2.
> 
> Adding Steven Rostedt to the cc. Steven, does that look like a possible case?

Possible: yes. Likely: no

The recent fix would require shutting down a CPU at the same time as a
tracepoint is enabled or disabled. Rather difficult to hit, but easier
on a virtual machine. If Jiri was not enabling/disabling tracepoints or
shutting down CPUs, then it would not be the bug.

But as the comm of the bug is gdb and this running on a virtual
machine, I think the bug may be elsewhere. Corrupt stack possibly?

-- Steve

  reply	other threads:[~2016-02-25 19:23 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-17 20:37 Linux 4.4.2 Greg KH
2016-02-17 20:37 ` Greg KH
2016-02-25 10:12 ` BUG: unable to handle kernel paging request from pty_write [was: Linux 4.4.2] Jiri Slaby
2016-02-25 18:40   ` Peter Hurley
2016-02-25 19:09     ` Linus Torvalds
2016-02-25 19:23       ` Steven Rostedt [this message]
2016-02-26  8:25         ` Jiri Slaby
2016-02-25 20:32       ` Peter Hurley
2016-02-25 20:51         ` Linus Torvalds
2016-02-25 21:32           ` Jiri Slaby
2016-02-25 22:33             ` Peter Hurley
2016-02-26  0:38               ` Peter Hurley
2016-02-26  8:45                 ` Jiri Slaby
2016-02-26  0:38             ` Linus Torvalds
2016-02-26  8:56               ` Jiri Slaby
2016-02-26  9:23                 ` Jiri Slaby
2016-02-26  9:50                   ` Jiri Slaby
2016-02-26 16:34                     ` Greg KH
2016-02-26 17:12                 ` Linus Torvalds
2016-02-29 15:45                   ` Paolo Bonzini
2016-02-26 17:52                 ` Peter Hurley
2016-02-25 21:43           ` Peter Hurley
2016-02-25 22:00           ` Jiri Kosina
2016-02-26  8:31             ` Jiri Slaby
2016-02-26  8:15     ` Jiri Slaby
2016-02-26 18:05 Linus Torvalds
2016-02-26 18:17 ` Borislav Petkov
2016-02-26 18:18 ` Peter Hurley
2016-02-26 19:44 ` Linus Torvalds
2016-02-26 19:59   ` Robert Święcki
2016-02-29  7:39     ` Jiri Slaby
2016-02-29 12:43       ` Henrique de Moraes Holschuh

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=20160225142338.42e46f2c@gandalf.local.home \
    --to=rostedt@goodmis.org \
    --cc=akpm@linux-foundation.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=jslaby@suse.cz \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lwn@lwn.net \
    --cc=peter@hurleysoftware.com \
    --cc=stable@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    /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.