From d50c68b2f05c7e899ca31da70a382b75f69399c7 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Tue, 22 Sep 2015 16:29:55 +0000
Subject: [PATCH] Re-check for new ast after ast was handled.  We should not
 return to usermode with pending asts.

Reviewed by:	andrew
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D3667
---
 sys/arm64/arm64/exception.S | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/sys/arm64/arm64/exception.S b/sys/arm64/arm64/exception.S
index b05941f5eac..9bbbde727ea 100644
--- a/sys/arm64/arm64/exception.S
+++ b/sys/arm64/arm64/exception.S
@@ -100,10 +100,11 @@ __FBSDID("$FreeBSD$");
 .macro	do_ast
 	/* Disable interrupts */
 	mrs	x19, daif
+1:
 	msr	daifset, #2
 
 	/* Read the current thread flags */
-1:	ldr	x1, [x18, #PC_CURTHREAD]	/* Load curthread */
+	ldr	x1, [x18, #PC_CURTHREAD]	/* Load curthread */
 	ldr	x2, [x1, #TD_FLAGS]
 
 	/* Check if we have either bits set */
@@ -120,9 +121,8 @@ __FBSDID("$FreeBSD$");
 	mov	x0, sp
 	bl	_C_LABEL(ast)
 
-	/* Disable interrupts */
-	mrs	x19, daif
-	msr	daifset, #2
+	/* Re-check for new ast scheduled */
+	b	1b
 
 2:
 	/* Restore interrupts */