From: semarie <semarie@openbsd.org>
Date: Tue, 19 Apr 2022 15:30:52 +0000 (+0000)
Subject: add missing unlock before returning in uvn_detach()
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=dc57f0abf248f41f686b541d07a1322bc2e97c28;p=openbsd

add missing unlock before returning in uvn_detach()

uvn_detach sets UVM_VNODE_RELKILL flag and wait for all async i/o to finish. but
uvm_vnp_terminate() could clear the flag and take over the vnode.

mpi@ noted that this code path is mostly dead code because there is no "async
I/O" (uvn_io() is always synchronous).

ok visa@ mpi@
---

diff --git a/sys/uvm/uvm_vnode.c b/sys/uvm/uvm_vnode.c
index c9e7dd63288..3f3de38b7c5 100644
--- a/sys/uvm/uvm_vnode.c
+++ b/sys/uvm/uvm_vnode.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_vnode.c,v 1.121 2021/12/15 12:53:53 mpi Exp $	*/
+/*	$OpenBSD: uvm_vnode.c,v 1.122 2022/04/19 15:30:52 semarie Exp $	*/
 /*	$NetBSD: uvm_vnode.c,v 1.36 2000/11/24 20:34:01 chs Exp $	*/
 
 /*
@@ -358,8 +358,10 @@ uvn_detach(struct uvm_object *uobj)
 		    INFSLP);
 	}
 
-	if ((uvn->u_flags & UVM_VNODE_RELKILL) == 0)
+	if ((uvn->u_flags & UVM_VNODE_RELKILL) == 0) {
+		rw_exit(uobj->vmobjlock);
 		return;
+	}
 
 	/*
 	 * kill object now.   note that we can't be on the sync q because