[PATCH v2 7/8] x86/xen: Add unwind hint annotations

From: Josh Poimboeuf
Date: Mon Sep 18 2017 - 22:44:52 EST


Add unwind hint annotations to the xen head code so the ORC unwinder can
read head_64.o.

hypercall_page needs empty annotations at 32-byte intervals to match the
'xen_hypercall_*' ELF functions at those locations.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
arch/x86/xen/xen-head.S | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 9753225289e8..124941d09b2b 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -9,6 +9,7 @@
#include <asm/boot.h>
#include <asm/asm.h>
#include <asm/page_types.h>
+#include <asm/unwind_hints.h>

#include <xen/interface/elfnote.h>
#include <xen/interface/features.h>
@@ -19,6 +20,7 @@
#ifdef CONFIG_XEN_PV
__INIT
ENTRY(startup_xen)
+ UNWIND_HINT_EMPTY
cld

/* Clear .bss */
@@ -40,7 +42,10 @@ END(startup_xen)
.pushsection .text
.balign PAGE_SIZE
ENTRY(hypercall_page)
- .skip PAGE_SIZE
+ .rept (PAGE_SIZE / 32)
+ UNWIND_HINT_EMPTY
+ .skip 32
+ .endr

#define HYPERCALL(n) \
.equ xen_hypercall_##n, hypercall_page + __HYPERVISOR_##n * 32; \
--
2.13.5