linux-kernel - [PATCH] x86/entry/64: add two more instruction suffixes

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Date:   Mon, 02 Jul 2018 04:47:57 -0600
From:   "Jan Beulich" <JBeulich@...e.com>
To:     <mingo@...e.hu>, <tglx@...utronix.de>, <hpa@...or.com>
Cc:     <linux-kernel@...r.kernel.org>
Subject: [PATCH] x86/entry/64: add two more instruction suffixes

Sadly, other than claimed in a368d7fd2a ("x86/entry/64: Add instruction
suffix"), there are two more instances which want to be adjusted. As
said there, omitting suffixes from instructions in AT&T mode is bad
practice when operand size cannot be determined by the assembler from
register operands, and is likely going to be warned about by upstream
gas in the future (mine does already). Add the other missing suffixes
here as well.

Signed-off-by: Jan Beulich <jbeulich@...e.com>
---
 arch/x86/entry/entry_64.S |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- 4.18-rc3/arch/x86/entry/entry_64.S
+++ 4.18-rc3-x86_64-entry-insn-suffix/arch/x86/entry/entry_64.S
@@ -92,7 +92,7 @@ END(native_usergs_sysret64)
 .endm

 .macro TRACE_IRQS_IRETQ_DEBUG
-	bt	$9, EFLAGS(%rsp)		/* interrupts off? */
+	btl	$9, EFLAGS(%rsp)		/* interrupts off? */
 	jnc	1f
 	TRACE_IRQS_ON_DEBUG
 1:
@@ -701,7 +701,7 @@ retint_kernel:
 #ifdef CONFIG_PREEMPT
 	/* Interrupts are off */
 	/* Check if we need preemption */
-	bt	$9, EFLAGS(%rsp)		/* were interrupts off? */
+	btl	$9, EFLAGS(%rsp)		/* were interrupts off? */
 	jnc	1f
 0:	cmpl	$0, PER_CPU_VAR(__preempt_count)
 	jnz	1f