linux-kernel - [tip:x86/pti] x86/entry/64: Move ASM_CLAC to interrupt

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Message-ID: <tip-a2bb5db1193effd900216a62a6d03d177c26ab02@git.kernel.org>
Date:   Wed, 21 Feb 2018 02:47:33 -0800
From:   tip-bot for Dominik Brodowski <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     luto@...nel.org, brgerst@...il.com, hpa@...or.com,
        linux-kernel@...r.kernel.org, bp@...en8.de, peterz@...radead.org,
        linux@...inikbrodowski.net, dwmw2@...radead.org,
        torvalds@...ux-foundation.org, dvlasenk@...hat.com,
        mingo@...nel.org, tglx@...utronix.de, jpoimboe@...hat.com
Subject: [tip:x86/pti] x86/entry/64: Move ASM_CLAC to interrupt_entry()

Commit-ID:  a2bb5db1193effd900216a62a6d03d177c26ab02
Gitweb:     https://git.kernel.org/tip/a2bb5db1193effd900216a62a6d03d177c26ab02
Author:     Dominik Brodowski <linux@...inikbrodowski.net>
AuthorDate: Tue, 20 Feb 2018 22:01:12 +0100
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 21 Feb 2018 10:04:47 +0100

x86/entry/64: Move ASM_CLAC to interrupt_entry()

Moving ASM_CLAC to interrupt_entry means two instructions (addq / pushq
and call interrupt_entry) are not covered by it. However, it offers a
noticeable size reduction (-.2k):

   text	   data	    bss	    dec	    hex	filename
  16882	      0	      0	  16882	   41f2	entry_64.o-orig
  16623	      0	      0	  16623	   40ef	entry_64.o

Suggested-by: Brian Gerst <brgerst@...il.com>
Signed-off-by: Dominik Brodowski <linux@...inikbrodowski.net>
Acked-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: David Woodhouse <dwmw2@...radead.org>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: dan.j.williams@...el.com
Link: http://lkml.kernel.org/r/20180220210113.6725-6-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/entry/entry_64.S | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 8ea03cf..42a4b65 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -572,6 +572,7 @@ END(irq_entries_start)
 /* 8(%rsp): ~(interrupt number) */
 ENTRY(interrupt_entry)
 	UNWIND_HINT_FUNC
+	ASM_CLAC
 	cld
 
 	testb	$3, CS-ORIG_RAX+8(%rsp)
@@ -614,7 +615,6 @@ END(interrupt_entry)
 	 */
 	.p2align CONFIG_X86_L1_CACHE_SHIFT
 common_interrupt:
-	ASM_CLAC
 	addq	$-0x80, (%rsp)			/* Adjust vector to [-256, -1] range */
 	call	interrupt_entry
 	UNWIND_HINT_REGS indirect=1
@@ -811,7 +811,6 @@ END(common_interrupt)
 .macro apicinterrupt3 num sym do_sym
 ENTRY(\sym)
 	UNWIND_HINT_IRET_REGS
-	ASM_CLAC
 	pushq	$~(\num)
 .Lcommon_\sym:
 	call	interrupt_entry