From 83ba1468ab9d92804507ce44f31965f51252c9d4 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Sun, 3 Nov 2019 11:52:50 +0000
Subject: [PATCH] amd64: Store %cr3 into pcpu saved_ucr3 on double fault.

Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
---
 sys/amd64/amd64/exception.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S
index 12ff584d1a22..6a0b09a474f2 100644
--- a/sys/amd64/amd64/exception.S
+++ b/sys/amd64/amd64/exception.S
@@ -349,6 +349,8 @@ IDTVEC(dblfault)
 	jz	1f			/* already running with kernel GS.base */
 	swapgs
 1:	lfence
+	movq	%cr3,%rax
+	movq	%rax,PCPU(SAVED_UCR3)
 	movq	PCPU(KCR3),%rax
 	cmpq	$~0,%rax
 	je	2f