Date: Fri, 4 Dec 2015 10:06:20 +0100
From: Torsten Duwe <duwe@lst.de>
To: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
        Michael Ellerman <mpe@ellerman.id.au>, Jiri Kosina <jkosina@suse.cz>,
        linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        live-patching@vger.kernel.org
Subject: Re: [PATCH v4 8/9] Implement kernel live patching for ppc64le
	(ABIv2)
Message-ID: <20151204090620.GB2861@lst.de>
References: <20151125172608.9588569260@newverein.lst.de> <20151125172937.9425E69260@newverein.lst.de> <20151203162445.GG8047@pathway.suse.cz>
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On Thu, Dec 03, 2015 at 05:24:45PM +0100, Petr Mladek wrote:
> > +++ b/arch/powerpc/include/asm/livepatch.h
> > @@ -0,0 +1,45 @@
> [...]
> > +#include <linux/module.h>
> > +#include <linux/ftrace.h>
> > +
> > +#ifdef CONFIG_LIVEPATCH
> > +static inline int klp_check_compiler_support(void)
> > +{
> > +#if !defined(_CALL_ELF) || _CALL_ELF != 2
> 
> I am just curious why we do not check CC_USING_MPROFILE_KERNEL
> like in the other similar locations. It would look less cryptic.
> But I am not sure if it is precise enough.

Because a ppc with a gcc > 4.8.5 is not sufficient. The code
currently only works for the PPC ELF ABI v2, a.k.a. ppc64le.
But now that you say it, CC_USING_MPROFILE_KERNEL should go
into that condition as well. Thanks!

	Torsten

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