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From: Lai Jiangshan <laijs@linux.alibaba.com>
To: linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	x86@kernel.org
Subject: [PATCH 0/2] x86/entry: simplify RESTORE_CR3
Date: Tue, 26 May 2020 04:35:05 +0000	[thread overview]
Message-ID: <20200526043507.51977-1-laijs@linux.alibaba.com> (raw)

When I searched percpu data touched by entry code for #DB
protection[1], it seems to me RESTORE_CR3() does too much work,
this patchset simplifies it.

Patch 1 enhances 21e944591102("x86/mm: Optimize RESTORE_CR3") for
kernel CR3.

Patch 2 *reverts* 21e944591102("x86/mm: Optimize RESTORE_CR3") for
User CR3.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: https://lore.kernel.org/lkml/20200525145102.122557-1-laijs@linux.alibaba.com
Lai Jiangshan (2):
  x86/entry: Don't write to CR3 when restoring to kernel CR3
  x86/entry: always flush user CR3 in RESTORE_CR3

 arch/x86/entry/calling.h  | 36 ++++++++----------------------------
 arch/x86/entry/entry_64.S |  6 +++---
 2 files changed, 11 insertions(+), 31 deletions(-)

-- 
2.20.1


             reply	other threads:[~2020-05-26  4:35 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-26  4:35 Lai Jiangshan [this message]
2020-05-26  4:35 ` [PATCH 1/2] x86/entry: Don't write to CR3 when restoring to kernel CR3 Lai Jiangshan
2020-05-26  4:35 ` [PATCH 2/2] x86/entry: always flush user CR3 in RESTORE_CR3 Lai Jiangshan
2020-05-29 18:17 ` [PATCH 0/2] x86/entry: simplify RESTORE_CR3 Andy Lutomirski

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