[PATCH 07/33] x86/asm/xen: Create stack frames in xen-asm.S

From: Josh Poimboeuf
Date: Thu Jan 21 2016 - 18:02:19 EST


xen_irq_enable_direct(), xen_restore_fl_direct(), and check_events() are
callable non-leaf functions which don't honor CONFIG_FRAME_POINTER,
which can result in bad stack traces.

Create stack frames for them when CONFIG_FRAME_POINTER is enabled.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
---
arch/x86/xen/xen-asm.S | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 3e45aa0..eff224d 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -14,6 +14,7 @@
#include <asm/asm-offsets.h>
#include <asm/percpu.h>
#include <asm/processor-flags.h>
+#include <asm/frame.h>

#include "xen-asm.h"

@@ -23,6 +24,7 @@
* then enter the hypervisor to get them handled.
*/
ENTRY(xen_irq_enable_direct)
+ FRAME_BEGIN
/* Unmask events */
movb $0, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask

@@ -39,6 +41,7 @@ ENTRY(xen_irq_enable_direct)
2: call check_events
1:
ENDPATCH(xen_irq_enable_direct)
+ FRAME_END
ret
ENDPROC(xen_irq_enable_direct)
RELOC(xen_irq_enable_direct, 2b+1)
@@ -82,6 +85,7 @@ ENDPATCH(xen_save_fl_direct)
* enters the hypervisor to get them delivered if so.
*/
ENTRY(xen_restore_fl_direct)
+ FRAME_BEGIN
#ifdef CONFIG_X86_64
testw $X86_EFLAGS_IF, %di
#else
@@ -100,6 +104,7 @@ ENTRY(xen_restore_fl_direct)
2: call check_events
1:
ENDPATCH(xen_restore_fl_direct)
+ FRAME_END
ret
ENDPROC(xen_restore_fl_direct)
RELOC(xen_restore_fl_direct, 2b+1)
@@ -109,7 +114,8 @@ ENDPATCH(xen_restore_fl_direct)
* Force an event check by making a hypercall, but preserve regs
* before making the call.
*/
-check_events:
+ENTRY(check_events)
+ FRAME_BEGIN
#ifdef CONFIG_X86_32
push %eax
push %ecx
@@ -139,4 +145,6 @@ check_events:
pop %rcx
pop %rax
#endif
+ FRAME_END
ret
+ENDPROC(check_events)
--
2.4.3