x86/asm: Add C versions of frame pointer macros

Add C versions of the frame pointer macros which can be used to
create a stack frame in inline assembly.

Signed-off-by: Josh Poimboeuf <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Bernd Petrovitsch <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Brian Gerst <[e-mail]>
Cc: Chris J Arges <[e-mail]>
Cc: Denys Vlasenko <[e-mail]>
Cc: H. Peter Anvin <[e-mail]>
Cc: Jiri Slaby <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Michal Marek <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Pedro Alves <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/include/asm/frame.h

···
 #ifndef _ASM_X86_FRAME_H
 #define _ASM_X86_FRAME_H
 
-#ifdef __ASSEMBLY__
-
 #include <asm/asm.h>
 
 /*
  * These are stack frame creation macros.  They should be used by every
  * callable non-leaf asm function to make kernel stack traces more reliable.
  */
+
 #ifdef CONFIG_FRAME_POINTER
+
+#ifdef __ASSEMBLY__
 
 .macro FRAME_BEGIN
 	push %_ASM_BP
···
 .macro FRAME_END
 	pop %_ASM_BP
 .endm
+
+#else /* !__ASSEMBLY__ */
+
+#define FRAME_BEGIN				\
+	"push %" _ASM_BP "\n"			\
+	_ASM_MOV "%" _ASM_SP ", %" _ASM_BP "\n"
+
+#define FRAME_END "pop %" _ASM_BP "\n"
+
+#endif /* __ASSEMBLY__ */
 
 #define FRAME_OFFSET __ASM_SEL(4, 8)
 
···
 
 #endif /* CONFIG_FRAME_POINTER */
 
-#endif  /*  __ASSEMBLY__  */
 #endif /* _ASM_X86_FRAME_H */