linux-kernel - [PATCH AUTOSEL 4.14 12/13] x86: math-emu: Fix up 'cmp' insn for clang ias

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Message-Id: <20200720213914.407919-12-sashal@kernel.org>
Date:   Mon, 20 Jul 2020 17:39:13 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Arnd Bergmann <arnd@...db.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Sasha Levin <sashal@...nel.org>,
        clang-built-linux@...glegroups.com
Subject: [PATCH AUTOSEL 4.14 12/13] x86: math-emu: Fix up 'cmp' insn for clang ias

From: Arnd Bergmann <arnd@...db.de>

[ Upstream commit 81e96851ea32deb2c921c870eecabf335f598aeb ]

The clang integrated assembler requires the 'cmp' instruction to
have a length prefix here:

arch/x86/math-emu/wm_sqrt.S:212:2: error: ambiguous instructions require an explicit suffix (could be 'cmpb', 'cmpw', or 'cmpl')
 cmp $0xffffffff,-24(%ebp)
 ^

Make this a 32-bit comparison, which it was clearly meant to be.

Signed-off-by: Arnd Bergmann <arnd@...db.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@...gle.com>
Link: https://lkml.kernel.org/r/20200527135352.1198078-1-arnd@arndb.de
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/x86/math-emu/wm_sqrt.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/math-emu/wm_sqrt.S b/arch/x86/math-emu/wm_sqrt.S
index f031c0e193565..515cdee90df72 100644
--- a/arch/x86/math-emu/wm_sqrt.S
+++ b/arch/x86/math-emu/wm_sqrt.S
@@ -209,7 +209,7 @@ sqrt_stage_2_finish:
 
 #ifdef PARANOID
 /* It should be possible to get here only if the arg is ffff....ffff */
-	cmp	$0xffffffff,FPU_fsqrt_arg_1
+	cmpl	$0xffffffff,FPU_fsqrt_arg_1
 	jnz	sqrt_stage_2_error
 #endif /* PARANOID */
 
-- 
2.25.1