From bf03b1f1f95eeb68aaebbdd3fa160c5dfd9d8141 Mon Sep 17 00:00:00 2001
From: Ruslan Bukin <br@FreeBSD.org>
Date: Tue, 7 May 2019 14:32:17 +0000
Subject: [PATCH] Disable interrupts first and then set spinlock_count to 1.
 Otherwise interrupt can be generated just after setting spinlock_count and
 before disabling interrupts.

Sponsored by:	DARPA, AFRL
---
 sys/riscv/riscv/machdep.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/riscv/riscv/machdep.c b/sys/riscv/riscv/machdep.c
index ae4c040dc47..417373744ae 100644
--- a/sys/riscv/riscv/machdep.c
+++ b/sys/riscv/riscv/machdep.c
@@ -457,11 +457,13 @@ void
 spinlock_enter(void)
 {
 	struct thread *td;
+	register_t reg;
 
 	td = curthread;
 	if (td->td_md.md_spinlock_count == 0) {
+		reg = intr_disable();
 		td->td_md.md_spinlock_count = 1;
-		td->td_md.md_saved_sstatus_ie = intr_disable();
+		td->td_md.md_saved_sstatus_ie = reg;
 	} else
 		td->td_md.md_spinlock_count++;
 	critical_enter();