x86/xen: Add unwind hint annotations to xen_setup_gdt

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>

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 081437b5f3814695cd45eb2f8b2f9cda6aee360d..e3a3f5a648846cd1d7faaf31aec2e0f7e4804466 100644 (file)
--- 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));