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From: Thomas Gleixner <tglx@linutronix.de>
To: Mike Galbraith <efault@gmx.de>
Cc: Borislav Petkov <bp@alien8.de>, "Tobin C. Harding" <me@tobin.cc>,
	LKML <linux-kernel@vger.kernel.org>,
	Nicholas Mc Guire <der.herr@hofr.at>,
	Vivek Goyal <vgoyal@redhat.com>,
	x86@kernel.org
Subject: Re: kexec, x86/purgatory: Cleanup the unholy mess
Date: Fri, 10 Mar 2017 14:57:38 +0100 (CET)	[thread overview]
Message-ID: <alpine.DEB.2.20.1703101457160.3681@nanos> (raw)
In-Reply-To: <1489153665.4410.4.camel@gmx.de>

On Fri, 10 Mar 2017, Mike Galbraith wrote:
> On Fri, 2017-03-10 at 13:17 +0100, Thomas Gleixner wrote:
> > The purgatory code defines global variables which are referenced via a
> > symbol lookup in the kexec code (core and arch).
> > 
> > A recent commit addressing sparse warning made these static and thereby
> > broke kexec file.
> > 
> > Why did this happen? Simply because the whole machinery is undocumented and
> > lacks any form of forward declarations. The variable names are unspecific
> > and lack a prefix, so adding forward declarations creates shadow variables
> > in the core code. Aside of that the code relies on magic constants and
> > duplicate struct definitions with no way to ensure that these things stay
> > in sync.
> > 
> > Unbreak kexec and cleanup the mess by:
> > 
> >  - Adding proper forward declarations and document the usage
> >  - Use the proper common defines instead of magic constants
> >  - Add a purgatory_ prefix to have a proper name space
> >  - Use ARRAY_SIZE() instead of a homebrewn reimplementation
> > 
> > Fixes: 72042a8c7b01 ("x86/purgatory: Make functions and variables static")
> 
> Well, almost fixes.
> 
> [   15.118820] kexec: symbol 'purgatory_sha_regions' in common section
> [   15.119187] kexec-bzImage64: Loading purgatory failed

Bah. /me goes to investigate.

  reply	other threads:[~2017-03-10 13:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-10 12:17 kexec, x86/purgatory: Cleanup the unholy mess Thomas Gleixner
2017-03-10 13:47 ` Mike Galbraith
2017-03-10 13:57   ` Thomas Gleixner [this message]
2017-03-10 14:24     ` Vivek Goyal
2017-03-10 14:58       ` Thomas Gleixner
2017-03-10 15:05         ` Vivek Goyal
2017-03-10 14:31     ` Mike Galbraith
2017-03-10 14:56       ` Thomas Gleixner
2017-03-10 14:58         ` Mike Galbraith
2017-03-10 15:31           ` Thomas Gleixner
2017-03-10 18:13             ` Mike Galbraith
2017-03-10 20:13 ` [tip:x86/urgent] kexec, x86/purgatory: Unbreak it and clean it up tip-bot for Thomas Gleixner

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