From: tip-bot for Xiaoyao Li <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: fenghua.yu@intel.com, xiaoyao.li@linux.intel.com,
tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com,
linux-kernel@vger.kernel.org, bp@alien8.de
Subject: [tip:x86/boot] x86/boot: Make gdt 8-byte aligned
Date: Thu, 27 Jun 2019 00:43:03 -0700 [thread overview]
Message-ID: <tip-1c30fe6cbba6997ae4740bb46910036f8a4a9edb@git.kernel.org> (raw)
In-Reply-To: <20190627045525.105266-1-xiaoyao.li@linux.intel.com>
Commit-ID: 1c30fe6cbba6997ae4740bb46910036f8a4a9edb
Gitweb: https://git.kernel.org/tip/1c30fe6cbba6997ae4740bb46910036f8a4a9edb
Author: Xiaoyao Li <xiaoyao.li@linux.intel.com>
AuthorDate: Thu, 27 Jun 2019 12:55:25 +0800
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 27 Jun 2019 09:40:41 +0200
x86/boot: Make gdt 8-byte aligned
The segment descriptors are loaded with a implicitly locked instruction,
which could trigger the split lock #AC if the variable is not properly
aligned and crosses a cache line.
Align gdt proper so the descriptors are 8 byte aligned.
Signed-off-by: Xiaoyao Li <xiaoyao.li@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: https://lkml.kernel.org/r/20190627045525.105266-1-xiaoyao.li@linux.intel.com
---
arch/x86/boot/compressed/head_64.S | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index fafb75c6c592..6233ae35d0d9 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -659,6 +659,7 @@ no_longmode:
gdt64:
.word gdt_end - gdt
.quad 0
+ .balign 8
gdt:
.word gdt_end - gdt
.long gdt
next prev parent reply other threads:[~2019-06-27 7:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-27 4:55 [PATCH] x86/boot: Make gdt 8-byte aligned Xiaoyao Li
2019-06-27 7:43 ` tip-bot for Xiaoyao Li [this message]
2019-06-27 9:01 ` [tip:x86/boot] x86/boot: Make the GDT " tip-bot for Xiaoyao Li
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