From ff0687b37fa923ecbbee25b8baeff96d77011fa1 Mon Sep 17 00:00:00 2001
From: Ilie Halip <ilie.halip@gmail.com>
Date: Thu, 19 Mar 2020 23:45:28 +0200
Subject: [PATCH] arm64: alternative: fix build with clang integrated assembler

commit 6f5459da2b8736720afdbd67c4bd2d1edba7d0e3 upstream.

Building an arm64 defconfig with clang's integrated assembler, this error
occurs:
    <instantiation>:2:2: error: unrecognized instruction mnemonic
     _ASM_EXTABLE 9999b, 9f
     ^
    arch/arm64/mm/cache.S:50:1: note: while in macro instantiation
    user_alt 9f, "dc cvau, x4", "dc civac, x4", 0
    ^

While GNU as seems fine with case-sensitive macro instantiations, clang
doesn't, so use the actual macro name (_asm_extable) as in the rest of
the file.

Also checked that the generated assembly matches the GCC output.

Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Fixes: 290622efc76e ("arm64: fix "dc cvau" cache operation on errata-affected core")
Link: https://github.com/ClangBuiltLinux/linux/issues/924
Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h
index b9f8d787eea9..97624ee1aaa3 100644
--- a/arch/arm64/include/asm/alternative.h
+++ b/arch/arm64/include/asm/alternative.h
@@ -211,7 +211,7 @@ alternative_endif
 
 .macro user_alt, label, oldinstr, newinstr, cond
 9999:	alternative_insn "\oldinstr", "\newinstr", \cond
-	_ASM_EXTABLE 9999b, \label
+	_asm_extable 9999b, \label
 .endm
 
 /*
-- 
2.7.4