x86/asm: Fix UNWIND_HINT_REGS macro for older binutils
authorJosh Poimboeuf <jpoimboe@redhat.com>
Mon, 7 Aug 2017 14:38:05 +0000 (09:38 -0500)
committerIngo Molnar <mingo@kernel.org>
Thu, 10 Aug 2017 12:16:19 +0000 (14:16 +0200)
commitaf79ded44b7c5eee46b433a9269fcf899372225b
tree93bef84309f9b1edcf812496c745ecbfe251a1fa
parent603e492e861861ddfec7139a007abad74f0d3af0
x86/asm: Fix UNWIND_HINT_REGS macro for older binutils

Apparently the binutils 2.20 assembler can't handle the '&&' operator in
the UNWIND_HINT_REGS macro.  Rearrange the macro to do without it.

This fixes the following error:

  arch/x86/entry/entry_64.S: Assembler messages:
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
  arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 39358a033b2e ("objtool, x86: Add facility for asm code to provide unwind hints")
Link: http://lkml.kernel.org/r/e2ad97c1ae49a484644b4aaa4dd3faa4d6d969b2.1502116651.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/include/asm/unwind_hints.h