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

From: Josh Poimboeuf
Date: Thu Aug 31 2017 - 16:24:41 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 | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 9753225289e8..8f9741cbb32f 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -19,6 +19,7 @@
#ifdef CONFIG_XEN_PV
__INIT
ENTRY(startup_xen)
+ UNWIND_HINT_EMPTY
cld

/* Clear .bss */
@@ -40,7 +41,10 @@ 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