From ebc0d29e14f08b76908ed872815ffe3d01df9a79 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Wed, 25 Aug 2021 22:28:57 +0300
Subject: [PATCH] amd64: remove lfence after swapgs on syscall entry

(cherry picked from commit 7aa47cace14948a7b8277a4b24a0ca9e0308990a)
---
 sys/amd64/amd64/exception.S | 2 --
 1 file changed, 2 deletions(-)

diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S
index 3fb51817940..bd9f235626e 100644
--- a/sys/amd64/amd64/exception.S
+++ b/sys/amd64/amd64/exception.S
@@ -525,7 +525,6 @@ prot_addrf:
 	SUPERALIGN_TEXT
 IDTVEC(fast_syscall_pti)
 	swapgs
-	lfence
 	cmpq	$~0,PCPU(UCR3)
 	je	fast_syscall_common
 	movq	%rax,PCPU(SCRATCH_RAX)
@@ -536,7 +535,6 @@ IDTVEC(fast_syscall_pti)
 	SUPERALIGN_TEXT
 IDTVEC(fast_syscall)
 	swapgs
-	lfence
 fast_syscall_common:
 	movq	%rsp,PCPU(SCRATCH_RSP)
 	movq	PCPU(RSP0),%rsp