[PATCH v17 6/9] x86/xen: Add xen_cpuid() to objtool whitelist

From: Josh Poimboeuf
Date: Wed Feb 24 2016 - 11:39:54 EST


'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@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
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 */

static bool __init xen_check_mwait(void)
{
--
2.4.3