linux-kernel - [tip: x86/entry] x86/entry/64: Remove unneeded kernel CR3 switching

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Date:   Thu, 07 May 2020 15:16:53 -0000
From:   "tip-bot2 for Lai Jiangshan" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Lai Jiangshan <laijs@...ux.alibaba.com>,
        Thomas Gleixner <tglx@...utronix.de>, x86 <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [tip: x86/entry] x86/entry/64: Remove unneeded kernel CR3 switching

The following commit has been merged into the x86/entry branch of tip:

Commit-ID:     f642aebc9d2a51775d86eaa79da9d90aa5dff0f7
Gitweb:        https://git.kernel.org/tip/f642aebc9d2a51775d86eaa79da9d90aa5dff0f7
Author:        Lai Jiangshan <laijs@...ux.alibaba.com>
AuthorDate:    Sun, 19 Apr 2020 14:40:47 
Committer:     Thomas Gleixner <tglx@...utronix.de>
CommitterDate: Thu, 07 May 2020 17:12:39 +02:00

x86/entry/64: Remove unneeded kernel CR3 switching

When native_load_gs_index() fails on .Lgs_change, CR3 must be kernel
CR3. No need to switch it.

Signed-off-by: Lai Jiangshan <laijs@...ux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Link: https://lkml.kernel.org/r/20200419144049.1906-2-laijs@linux.alibaba.com

---
 arch/x86/entry/entry_64.S | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 3d747da..7d40d10 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1338,7 +1338,6 @@ SYM_CODE_START_LOCAL(error_entry)
 	 */
 	SWAPGS
 	FENCE_SWAPGS_USER_ENTRY
-	SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
 	jmp .Lerror_entry_done
 
 .Lbstep_iret: