[PATCH linux-next] ARM: unwind: use ex_frame with CONFIG_UNWINDER_FRAME_POINTER

[guo.ziliang]

From: guo ziliang <guo.ziliang@xxxxxxxxxx>

We define ex_frame with CONFIG_UNWINDER_FRAME_POINTER in struct stackframe,
struct stackframe
{
	......
#ifdef CONFIG_UNWINDER_FRAME_POINTER
	bool ex_frame;
#endif
};
but we just use ex_frame without CONFIG_UNWINDER_FRAME_POINTER in return_address()
and unwind_frame(). 
so when we config CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=n, compile failed:
arch/arm/kernel/stacktrace.c: In function 'unwind_frame':
arch/arm/kernel/stacktrace.c:44:11: error: 'struct stackframe' has no member named 'ex_frame'
  if (frame->ex_frame) {
           ^~
arch/arm/kernel/stacktrace.c:57:8: error: 'struct stackframe' has no member named 'ex_frame'
   frame->ex_frame = false;
        ^~
arch/arm/kernel/stacktrace.c:67:8: error: 'struct stackframe' has no member named 'ex_frame'
   frame->ex_frame = true;
        ^~
		
Maybe we should fix it.

Signed-off-by: guo ziliang <guo.ziliang@xxxxxxxxxx>
---
 arch/arm/kernel/return_address.c | 2 ++
 arch/arm/kernel/stacktrace.c     | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/arch/arm/kernel/return_address.c b/arch/arm/kernel/return_address.c
index ac15db6..dae49e7 100644
--- a/arch/arm/kernel/return_address.c
+++ b/arch/arm/kernel/return_address.c
@@ -47,7 +47,9 @@ void *return_address(unsigned int level)
 	frame.kr_cur = NULL;
 	frame.tsk = current;
 #endif
+#ifdef CONFIG_UNWINDER_FRAME_POINTER
 	frame.ex_frame = false;
+#endif

 	walk_stackframe(&frame, save_return_addr, &data);

diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c
index 620aa82..338f552 100644
--- a/arch/arm/kernel/stacktrace.c
+++ b/arch/arm/kernel/stacktrace.c
@@ -82,6 +82,7 @@ int notrace unwind_frame(struct stackframe *frame)
 	if (frame_pointer_check(frame))
 		return -EINVAL;

+#ifdef CONFIG_UNWINDER_FRAME_POINTER
 	/*
 	 * When we unwind through an exception stack, include the saved PC
 	 * value into the stack trace.
@@ -102,6 +103,7 @@ int notrace unwind_frame(struct stackframe *frame)
 		frame->ex_frame = false;
 		return 0;
 	}
+#endif

 	/* restore the registers from the stack frame */
 #ifdef CONFIG_CC_IS_CLANG
@@ -119,8 +121,10 @@ int notrace unwind_frame(struct stackframe *frame)
 					(void *)frame->fp, &frame->kr_cur);
 #endif

+#ifdef CONFIG_UNWINDER_FRAME_POINTER
 	if (in_entry_text(frame->pc))
 		frame->ex_frame = true;
+#endif

 	return 0;
 }
-- 
1.8.3.1