From e4be2748a36158a82ebe911cf8e102ea5cdf9b8e Mon Sep 17 00:00:00 2001
From: rmind <rmind@NetBSD.org>
Date: Tue, 27 Oct 2009 02:58:28 +0000
Subject: [PATCH] - Amend fd_hold() to take an argument and add assert
 (reflects two cases,   fork1() and the rest, e.g. kthread_create(), when
 creating from lwp0).

- lwp_create(): do not touch filedesc internals, use fd_hold().
---
 sys/kern/kern_descrip.c | 10 ++++++----
 sys/kern/kern_lwp.c     |  6 +++---
 sys/sys/filedesc.h      |  4 ++--
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index c4ed03721572..a4d200b391bb 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_descrip.c,v 1.199 2009/08/16 11:00:20 yamt Exp $	*/
+/*	$NetBSD: kern_descrip.c,v 1.200 2009/10/27 02:58:28 rmind Exp $	*/
 
 /*-
  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.199 2009/08/16 11:00:20 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_descrip.c,v 1.200 2009/10/27 02:58:28 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1326,10 +1326,12 @@ fd_share(struct proc *p2)
  * Acquire a hold on a filedesc structure.
  */
 void
-fd_hold(void)
+fd_hold(lwp_t *l)
 {
+	filedesc_t *fdp = l->l_fd;
 
-	atomic_inc_uint(&curlwp->l_fd->fd_refcnt);
+	KASSERT(fdp == curlwp->l_fd || fdp == lwp0.l_fd);
+	atomic_inc_uint(&fdp->fd_refcnt);
 }
 
 /*
diff --git a/sys/kern/kern_lwp.c b/sys/kern/kern_lwp.c
index ee3f5c6cbf60..df797e31c070 100644
--- a/sys/kern/kern_lwp.c
+++ b/sys/kern/kern_lwp.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: kern_lwp.c,v 1.135 2009/10/22 22:28:57 rmind Exp $	*/
+/*	$NetBSD: kern_lwp.c,v 1.136 2009/10/27 02:58:28 rmind Exp $	*/
 
 /*-
  * Copyright (c) 2001, 2006, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -209,7 +209,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.135 2009/10/22 22:28:57 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_lwp.c,v 1.136 2009/10/27 02:58:28 rmind Exp $");
 
 #include "opt_ddb.h"
 #include "opt_lockdebug.h"
@@ -606,7 +606,7 @@ lwp_create(lwp_t *l1, proc_t *p2, vaddr_t uaddr, int flags,
 	l2->l_fd = p2->p_fd;
 	if (p2->p_nlwps != 0) {
 		KASSERT(l1->l_proc == p2);
-		atomic_inc_uint(&l2->l_fd->fd_refcnt);
+		fd_hold(l2);
 	} else {
 		KASSERT(l1->l_proc != p2);
 	}
diff --git a/sys/sys/filedesc.h b/sys/sys/filedesc.h
index a8329b996bb2..5e4213e9155f 100644
--- a/sys/sys/filedesc.h
+++ b/sys/sys/filedesc.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: filedesc.h,v 1.56 2009/05/25 03:59:45 yamt Exp $	*/
+/*	$NetBSD: filedesc.h,v 1.57 2009/10/27 02:58:28 rmind Exp $	*/
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -190,7 +190,7 @@ void	fd_abort(struct proc *, file_t *, unsigned);
 filedesc_t *fd_copy(void);
 filedesc_t *fd_init(filedesc_t *);
 void	fd_share(proc_t *);
-void	fd_hold(void);
+void	fd_hold(lwp_t *);
 void	fd_free(void);
 void	fd_closeexec(void);
 int	fd_checkstd(void);