Re: [PATCH 4/4] x86/jump-label: Show where and what was wrong on errors

From: "H. Peter Anvin" <hpa@zytor.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>,
	linux-kernel@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Jason Baron <jbaron@akamai.com>
Subject: Re: [PATCH 4/4] x86/jump-label: Show where and what was wrong on errors
Date: Wed, 07 Aug 2013 10:51:43 -0700	[thread overview]
Message-ID: <5202892F.7010804@zytor.com> (raw)
In-Reply-To: <1375897584.6848.15.camel@gandalf.local.home>

On 08/07/2013 10:46 AM, Steven Rostedt wrote:
> On Wed, 2013-08-07 at 19:37 +0200, Borislav Petkov wrote:
>> On Wed, Aug 07, 2013 at 01:33:06PM -0400, Steven Rostedt wrote:
>>> Right, and this code keeps the same logic as it was before. If it was
>>> disabled by CONFIG_EXPERT, it stays disabled, but at least you get to
>>> see a warning that your kernel may be corrupt now :-)
>>
>> Don't we really want to panic instead of running a corrupt kernel? IOW,
>> to change the logic to panic unconditionally because the image in memory
>> has been violated and not in a good way, at that :-)
> 
> Well, there's lots of places that use BUG() for a corrupt kernel. If you
> are stupid enough to disable it, you get what you asked for.
> 

A bigger issue is probably if panic-on-bug should be the default, with
!panic being an opt-in debugging option.

	-hpa