Re: [PATCH v3 1/2] x86/mm: Identify the end of the kernel area to be reserved

From: Greg KH <gregkh@linuxfoundation.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: "H.J. Lu" <hjl.tools@gmail.com>,
	Mike Lothian <mike@fireburn.co.uk>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	bhe@redhat.com, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	lijiang@redhat.com,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	the arch/x86 maintainers <x86@kernel.org>
Subject: Re: [PATCH v3 1/2] x86/mm: Identify the end of the kernel area to be reserved
Date: Tue, 23 Jul 2019 15:44:54 +0200	[thread overview]
Message-ID: <20190723134454.GA7260@kroah.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1907231519430.1659@nanos.tec.linutronix.de>

On Tue, Jul 23, 2019 at 03:31:32PM +0200, Thomas Gleixner wrote:
> On Tue, 23 Jul 2019, Greg KH wrote:
> > On Mon, Jul 15, 2019 at 01:16:48PM -0700, H.J. Lu wrote:
> > > >
> > > 
> > > Since building a workable kernel for different kernel configurations isn't a
> > > requirement for gold, I don't recommend gold for kernel.
> > 
> > Um, it worked before this commit, and now it doesn't.  "Some" companies
> > are using gold for linking the kernel today...
> 
> gold is known to fail the kernel build. x32 vdso linking is not working
> since years and just because it 'works' for some configurations and breaks
> for no valid reasons even with those configurations is just not good
> enough.
> 
> As there is obviously no priority for fixing gold to work proper with the
> kernel, I'm not at all interested in these 'regression' reports and in odd
> 'fixes' which just end up reverting or modifying perfectly valid changes
> without understanding the root cause, i.e. the most horrible engineering
> principle: duct-taping.
> 
> TBH, I'm tired of it. We fail the build for clang if it does not support
> asm gotos and the clang people are actively working on fixing it and we're
> helping them as much as we can. The companies who used clang nevertheless
> have been on their own for years and if someone wants to use gold then
> nobody is preventing them from doing so. They can keep their duct-tape in
> their own trees.
> 
> See this thread for further discussion:
> 
>  https://lkml.kernel.org/r/alpine.DEB.2.21.1907161434260.1767@nanos.tec.linutronix.de

Sorry, I saw that after writing that.  You are right, if the others
don't object, that's fine with me.  I'll go poke the various build
systems that are failing right now on 5.3-rc1 and try to get them fixed
for this reason.

thanks,

greg k-h