x86_64: Check for .cfi_rel_offset in CFI probe

Very old 64bit binutils have .cfi_startproc/endproc, but
no .cfi_rel_offset. Check for .cfi_rel_offset too.

Cc: Jan Beulich <jbeulich@novell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86_64/Makefile b/arch/x86_64/Makefile
index 128561d..b024e4a 100644
--- a/arch/x86_64/Makefile
+++ b/arch/x86_64/Makefile
@@ -57,8 +57,8 @@
 cflags-y += -maccumulate-outgoing-args
 
 # do binutils support CFI?
-cflags-y += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
-AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+cflags-y += $(call as-instr,.cfi_startproc\n.cfi_rel_offset rsp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
+AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_rel_offset rsp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
 
 # is .cfi_signal_frame supported too?
 cflags-y += $(call as-instr,.cfi_startproc\n.cfi_signal_frame\n.cfi_endproc,-DCONFIG_AS_CFI_SIGNAL_FRAME=1,)