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 <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/f6786a282bf232ede3e2866414eae3cf02c7d662.1450442274.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/frame.h

@@ -1,16 +1,17 @@
 #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
 	_ASM_MOV %_ASM_SP, %_ASM_BP
@@ -20,6 +21,16 @@
 	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)
 
 #else /* !CONFIG_FRAME_POINTER */
@@ -30,5 +41,4 @@
 
 #endif /* CONFIG_FRAME_POINTER */
 
-#endif  /*  __ASSEMBLY__  */
 #endif /* _ASM_X86_FRAME_H */