[PATCH 29/29] x86/xen: Add unwind hint annotations to xen_setup_gdt

Greg Kroah-Hartman
2018-06-03T12:28:58Z

Not needed in mainline as this function got rewritten in 4.12

This enables objtool to grok the iret in the middle of a C function.

This matches commit 76846bf3cb09 ("x86/asm: Add unwind hint annotations
to sync_core()")

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/xen/enlighten.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 081437b5f381..e3a3f5a64884 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -75,6 +75,7 @@
#include <asm/mwait.h>
#include <asm/pci_x86.h>
#include <asm/cpu.h>
+#include <asm/unwind_hints.h>

#ifdef CONFIG_ACPI
#include <linux/acpi.h>
@@ -1452,10 +1453,12 @@ static void __ref xen_setup_gdt(int cpu)
* GDT. The new GDT has __KERNEL_CS with CS.L = 1
* and we are jumping to reload it.
*/
- asm volatile ("pushq %0\n"
+ asm volatile (UNWIND_HINT_SAVE
+ "pushq %0\n"
"leaq 1f(%%rip),%0\n"
"pushq %0\n"
"lretq\n"
+ UNWIND_HINT_RESTORE
"1:\n"
: "=&r" (dummy) : "0" (__KERNEL_CS));

--
2.17.1