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Date: Thu, 25 Feb 2016 08:54:04 +0100
From: Ingo Molnar <mingo@kernel.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, live-patching@vger.kernel.org,
        Michal Marek <mmarek@suse.cz>, Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andi Kleen <andi@firstfloor.org>, Pedro Alves <palves@redhat.com>,
        Namhyung Kim <namhyung@gmail.com>,
        Bernd Petrovitsch <bernd@petrovitsch.priv.at>,
        Chris J Arges <chris.j.arges@canonical.com>,
        Andrew Morton <akpm@linux-foundation.org>, Jiri Slaby <jslaby@suse.cz>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        David Vrabel <david.vrabel@citrix.com>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>
Subject: Re: [PATCH v17 6/9] x86/xen: Add xen_cpuid() to objtool whitelist
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* Josh Poimboeuf <jpoimboe@redhat.com> wrote:

> 'objtool check' reports the following false positive warning:
> 
>   objtool: arch/x86/xen/enlighten.o: xen_cpuid()+0x41: can't find jump dest instruction at .text+0x108
> 
> The warning is due to xen_cpuid()'s use of XEN_EMULATE_PREFIX to insert
> some fake instructions which objtool doesn't know how to decode.
> 
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> Cc: David Vrabel <david.vrabel@citrix.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> ---
>  arch/x86/xen/enlighten.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index d09e4c9..b7f5909 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -32,6 +32,7 @@
>  #include <linux/gfp.h>
>  #include <linux/memblock.h>
>  #include <linux/edd.h>
> +#include <linux/objtool.h>
>  
>  #ifdef CONFIG_KEXEC_CORE
>  #include <linux/kexec.h>
> @@ -351,8 +352,8 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
>  	*cx &= maskecx;
>  	*cx |= setecx;
>  	*dx &= maskedx;
> -
>  }
> +STACK_FRAME_NON_STANDARD(xen_cpuid); /* XEN_EMULATE_PREFIX */

Could you please change the title and changelog of all such annotation patches to 
say something like:

  x86/xen: Mark xen_cpuid() stack frame as non-standard

?

It's not an objtool whitelist anymore, but a more generic annotation that objtool 
uses.

Thanks,

	Ingo