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From: tip-bot for Alexander Kuleshov <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: ryabinin.a.a@gmail.com, mingo@kernel.org, alpopov@ptsecurity.com,
	linux-kernel@vger.kernel.org, luto@kernel.org,
	luto@amacapital.net, brgerst@gmail.com, bp@alien8.de,
	dvlasenk@redhat.com, peterz@infradead.org,
	kuleshovmail@gmail.com, torvalds@linux-foundation.org,
	tglx@linutronix.de, hpa@zytor.com, bp@suse.de
Subject: [tip:x86/boot] x86/boot: Simplify kernel load address alignment check
Date: Sat, 30 Jan 2016 05:20:52 -0800	[thread overview]
Message-ID: <tip-a4733143085d6c782ac1e6c85778655b6bac1d4e@git.kernel.org> (raw)
In-Reply-To: <1453842730-28463-11-git-send-email-bp@alien8.de>

Commit-ID:  a4733143085d6c782ac1e6c85778655b6bac1d4e
Gitweb:     http://git.kernel.org/tip/a4733143085d6c782ac1e6c85778655b6bac1d4e
Author:     Alexander Kuleshov <kuleshovmail@gmail.com>
AuthorDate: Tue, 26 Jan 2016 22:12:10 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Sat, 30 Jan 2016 11:22:48 +0100

x86/boot: Simplify kernel load address alignment check

We are using %rax as temporary register to check the kernel
address alignment. We don't really have to since the TEST
instruction does not clobber the destination operand.

Suggested-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
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>
Link: http://lkml.kernel.org/r/1453531828-19291-1-git-send-email-kuleshovmail@gmail.com
Link: http://lkml.kernel.org/r/1453842730-28463-11-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/head_64.S | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index ffdc0e8..7c21029 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -76,9 +76,7 @@ startup_64:
 	subq	$_text - __START_KERNEL_map, %rbp
 
 	/* Is the address not 2M aligned? */
-	movq	%rbp, %rax
-	andl	$~PMD_PAGE_MASK, %eax
-	testl	%eax, %eax
+	testl	$~PMD_PAGE_MASK, %ebp
 	jnz	bad_address
 
 	/*

  reply	other threads:[~2016-01-30 13:22 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-26 21:12 [PATCH 00/10] tip-queue 2016-01-26, rest Borislav Petkov
2016-01-26 21:12 ` [PATCH 01/10] x86/asm: Add condition codes clobber to memory barrier macros Borislav Petkov
2016-01-26 21:12 ` [PATCH 02/10] x86/asm: Drop a comment left over from X86_OOSTORE Borislav Petkov
2016-01-26 21:12 ` [PATCH 03/10] x86/asm: Tweak the comment about wmb() use for IO Borislav Petkov
2016-01-26 21:12 ` [PATCH 04/10] x86/cpufeature: Carve out X86_FEATURE_* Borislav Petkov
2016-01-30 13:18   ` [tip:x86/asm] " tip-bot for Borislav Petkov
2016-01-26 21:12 ` [PATCH 05/10] x86/cpufeature: Replace the old static_cpu_has() with safe variant Borislav Petkov
2016-01-30 13:19   ` [tip:x86/asm] " tip-bot for Borislav Petkov
2016-01-26 21:12 ` [PATCH 06/10] x86/cpufeature: Get rid of the non-asm goto variant Borislav Petkov
2016-01-27  3:36   ` Brian Gerst
2016-01-27  8:41     ` Borislav Petkov
2016-01-27  8:43       ` [PATCH -v1.1 " Borislav Petkov
2016-01-30 13:19         ` [tip:x86/asm] " tip-bot for Borislav Petkov
2016-01-27  8:45       ` [PATCH -v1.1 8/10] x86/alternatives: Discard dynamic check after init Borislav Petkov
2016-01-30 13:20         ` [tip:x86/asm] " tip-bot for Brian Gerst
2016-01-26 21:12 ` [PATCH 07/10] x86/alternatives: Add an auxilary section Borislav Petkov
2016-01-30 13:19   ` [tip:x86/asm] " tip-bot for Borislav Petkov
2016-01-26 21:12 ` [PATCH 08/10] x86/alternatives: Discard dynamic check after init Borislav Petkov
2016-01-26 21:12 ` [PATCH 09/10] x86/vdso: Use static_cpu_has() Borislav Petkov
2016-01-30 13:20   ` [tip:x86/asm] " tip-bot for Borislav Petkov
2016-01-26 21:12 ` [PATCH 10/10] x86/head_64: Simplify kernel load address alignment check Borislav Petkov
2016-01-30 13:20   ` tip-bot for Alexander Kuleshov [this message]
  -- strict thread matches above, loose matches on Subject: below --
2016-01-23  6:50 [PATCH] x86/head_64.S: do not use temporary register to check alignment Alexander Kuleshov
2016-01-26  9:31 ` Borislav Petkov
2016-01-16 19:22 [PATCH] x86: static_cpu_has_safe: discard dynamic check after init Brian Gerst
2016-01-16 19:36 ` Borislav Petkov
2016-01-16 19:58   ` Brian Gerst
2016-01-17 10:33     ` Borislav Petkov
2016-01-18 16:52       ` Brian Gerst
2016-01-18 17:49         ` Andy Lutomirski
2016-01-18 18:14         ` Borislav Petkov
2016-01-18 18:29           ` Andy Lutomirski
2016-01-18 18:39             ` Borislav Petkov
2016-01-18 19:45               ` H. Peter Anvin
2016-01-18 23:05                 ` Borislav Petkov
2016-01-18 23:13                   ` H. Peter Anvin
2016-01-18 23:25                     ` Borislav Petkov
2016-01-19 13:57                       ` Borislav Petkov
2016-01-19 16:23                         ` Borislav Petkov
2016-01-19 23:10                         ` Borislav Petkov
2016-01-19 23:26                           ` Andy Lutomirski
2016-01-19 23:49                             ` Boris Petkov
2016-01-20  4:03                         ` H. Peter Anvin
2016-01-20 10:33                           ` Borislav Petkov
2016-01-20 10:41                             ` H. Peter Anvin
2016-01-21 22:14                               ` Borislav Petkov
2016-01-21 22:22                                 ` H. Peter Anvin
2016-01-21 22:56                                   ` Borislav Petkov
2016-01-21 23:36                                     ` H. Peter Anvin
2016-01-21 23:37                                     ` H. Peter Anvin
2016-01-22 10:32                                       ` Borislav Petkov
2016-01-18 18:51           ` Borislav Petkov
2016-01-19  1:10             ` Borislav Petkov
2016-01-19  1:33               ` H. Peter Anvin
2016-01-19  9:22                 ` Borislav Petkov
2016-01-20  4:02                   ` H. Peter Anvin
2016-01-20  4:39                     ` Brian Gerst
2016-01-20  4:42                       ` H. Peter Anvin
2016-01-20 10:50                         ` Borislav Petkov
2016-01-20 10:55                           ` H. Peter Anvin
2016-01-20 11:05                             ` Borislav Petkov
2016-01-20 14:48                               ` H. Peter Anvin
2016-01-20 15:01                     ` Borislav Petkov
2016-01-20 15:09                       ` H. Peter Anvin
2016-01-20 16:04                         ` Borislav Petkov
2016-01-20 16:16                           ` H. Peter Anvin

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