All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andi Kleen <ak@linux.intel.com>
To: Prarit Bhargava <prarit@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>,
	kexec@lists.infradead.org, jason.wessel@windriver.com,
	Rusty Russell <rusty@rustcorp.com.au>,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Fabian Frederick <fabf@skynet.be>,
	isimatu.yasuaki@jp.fujitsu.com, "H. Peter Anvin" <hpa@zytor.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-api@vger.kernel.org, vgoyal@redhat.com
Subject: Re: [PATCH V4] kernel, add bug_on_warn
Date: Tue, 28 Oct 2014 05:16:36 -0700	[thread overview]
Message-ID: <20141028121636.GC3274@tassilo.jf.intel.com> (raw)
In-Reply-To: <1414155207-29839-1-git-send-email-prarit@redhat.com>

On Fri, Oct 24, 2014 at 08:53:27AM -0400, Prarit Bhargava wrote:
> There have been several times where I have had to rebuild a kernel to
> cause a panic when hitting a WARN() in the code in order to get a crash
> dump from a system.  Sometimes this is easy to do, other times (such as
> in the case of a remote admin) it is not trivial to send new images to the
> user.
> 
> A much easier method would be a switch to change the WARN() over to a
> BUG().  This makes debugging easier in that I can now test the actual
> image the WARN() was seen on and I do not have to engage in remote
> debugging.

IMHO this would be better and far more generically done with kdb. 
You would need two things:

- Extend the break point command to run another command on a break point.
- Add a command line (or possibly /proc) option to execute some kdb commands at
kernel boot.

Then just set a break point on the warn function and execute magic sysrq c
from kdb.

-Andi

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Andi Kleen <ak@linux.intel.com>
To: Prarit Bhargava <prarit@redhat.com>
Cc: linux-kernel@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rusty Russell <rusty@rustcorp.com.au>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	Fabian Frederick <fabf@skynet.be>,
	vgoyal@redhat.com, isimatu.yasuaki@jp.fujitsu.com,
	linux-doc@vger.kernel.org, kexec@lists.infradead.org,
	linux-api@vger.kernel.org, jason.wessel@windriver.com
Subject: Re: [PATCH V4] kernel, add bug_on_warn
Date: Tue, 28 Oct 2014 05:16:36 -0700	[thread overview]
Message-ID: <20141028121636.GC3274@tassilo.jf.intel.com> (raw)
In-Reply-To: <1414155207-29839-1-git-send-email-prarit@redhat.com>

On Fri, Oct 24, 2014 at 08:53:27AM -0400, Prarit Bhargava wrote:
> There have been several times where I have had to rebuild a kernel to
> cause a panic when hitting a WARN() in the code in order to get a crash
> dump from a system.  Sometimes this is easy to do, other times (such as
> in the case of a remote admin) it is not trivial to send new images to the
> user.
> 
> A much easier method would be a switch to change the WARN() over to a
> BUG().  This makes debugging easier in that I can now test the actual
> image the WARN() was seen on and I do not have to engage in remote
> debugging.

IMHO this would be better and far more generically done with kdb. 
You would need two things:

- Extend the break point command to run another command on a break point.
- Add a command line (or possibly /proc) option to execute some kdb commands at
kernel boot.

Then just set a break point on the warn function and execute magic sysrq c
from kdb.

-Andi

  parent reply	other threads:[~2014-10-28 12:16 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-24 12:53 [PATCH V4] kernel, add bug_on_warn Prarit Bhargava
2014-10-24 12:53 ` Prarit Bhargava
2014-10-27 18:05 ` Jason Baron
2014-10-27 18:05   ` Jason Baron
2014-10-27 18:05   ` Jason Baron
2014-10-27 18:15   ` Prarit Bhargava
2014-10-27 18:15     ` Prarit Bhargava
2014-10-27 18:15     ` Prarit Bhargava
2014-10-28  2:32     ` Dave Young
2014-10-28  2:32       ` Dave Young
2014-10-28  5:41     ` Masami Hiramatsu
2014-10-28  5:41       ` Masami Hiramatsu
2014-10-28  0:00 ` Yasuaki Ishimatsu
2014-10-28  0:00   ` Yasuaki Ishimatsu
2014-10-28  0:00   ` Yasuaki Ishimatsu
2014-10-28 12:16 ` Andi Kleen [this message]
2014-10-28 12:16   ` Andi Kleen
2014-10-28 12:22   ` Prarit Bhargava
2014-10-28 12:22     ` Prarit Bhargava
2014-10-28 12:22     ` Prarit Bhargava
2014-10-28 12:29     ` Vivek Goyal
2014-10-28 12:29       ` Vivek Goyal
2014-10-28 12:44       ` Andi Kleen
2014-10-28 12:44         ` Andi Kleen
2014-10-28 12:48         ` Prarit Bhargava
2014-10-28 12:48           ` Prarit Bhargava
2014-10-28 12:48           ` Prarit Bhargava
2014-10-28 12:56           ` Andi Kleen
2014-10-28 12:56             ` Andi Kleen
2014-10-28 12:56             ` Andi Kleen
2014-10-28 13:19             ` Prarit Bhargava
2014-10-28 13:19               ` Prarit Bhargava
2014-10-28 13:19               ` Prarit Bhargava
2014-10-28 12:55         ` Vivek Goyal
2014-10-28 12:55           ` Vivek Goyal
2014-10-28 12:59           ` Andi Kleen
2014-10-28 12:59             ` Andi Kleen

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=20141028121636.GC3274@tassilo.jf.intel.com \
    --to=ak@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=corbet@lwn.net \
    --cc=fabf@skynet.be \
    --cc=hpa@zytor.com \
    --cc=isimatu.yasuaki@jp.fujitsu.com \
    --cc=jason.wessel@windriver.com \
    --cc=kexec@lists.infradead.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=masami.hiramatsu.pt@hitachi.com \
    --cc=prarit@redhat.com \
    --cc=rusty@rustcorp.com.au \
    --cc=vgoyal@redhat.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 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.