Commit 983bb6d2 authored Feb 28, 2016 by Josh Poimboeuf Committed by Ingo Molnar Feb 29, 2016

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



objtool reports the following false positive warning:

  arch/x86/xen/enlighten.o: warning: objtool: 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: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/bb88399840406629e3417831dc371ecd2842e2a6.1456719558.git.jpoimboe@redhat.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 9a99417a

arch/x86/xen/enlighten.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@
		#include <linux/gfp.h>
		#include <linux/memblock.h>
		#include <linux/edd.h>
		#include <linux/frame.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 */

		static bool __init xen_check_mwait(void)
		{