[src/netbsd-2]: src/sys/miscfs/specfs Pull up following revision(s) (requeste...

[riz <riz%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/775a6f2636d9
branches:  netbsd-2
changeset: 564399:775a6f2636d9
user:      riz <riz%NetBSD.org@localhost>
date:      Thu Dec 29 01:36:30 2005 +0000

description:
Pull up following revision(s) (requested by chs in ticket #10207):
        sys/miscfs/specfs/spec_vnops.c: revision 1.83
in spec_ioctl(), don't dereference v_specinfo if it's NULL.
this is needed due to rev. 1.231 of kern/vfs_subr.c, which now sets
v_specinfo to NULL before changing the vnode's ops vector.

diffstat:

 sys/miscfs/specfs/spec_vnops.c |  25 +++++++++++++++++++++----
 1 files changed, 21 insertions(+), 4 deletions(-)

diffs (47 lines):

diff -r 68211cd24285 -r 775a6f2636d9 sys/miscfs/specfs/spec_vnops.c
--- a/sys/miscfs/specfs/spec_vnops.c    Thu Dec 29 01:21:35 2005 +0000
+++ b/sys/miscfs/specfs/spec_vnops.c    Thu Dec 29 01:36:30 2005 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: spec_vnops.c,v 1.77 2004/02/14 00:00:56 hannken Exp $  */
+/*     $NetBSD: spec_vnops.c,v 1.77.4.1 2005/12/29 01:36:30 riz Exp $  */
 
 /*
  * Copyright (c) 1989, 1993
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.77 2004/02/14 00:00:56 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.77.4.1 2005/12/29 01:36:30 riz Exp $");
 
 #include <sys/param.h>
 #include <sys/proc.h>
@@ -460,9 +460,26 @@
        } */ *ap = v;
        const struct bdevsw *bdev;
        const struct cdevsw *cdev;
-       dev_t dev = ap->a_vp->v_rdev;
+       struct vnode *vp;
+       dev_t dev;
+
+       /*
+        * Extract all the info we need from the vnode, taking care to
+        * avoid a race with VOP_REVOKE().
+        */
 
-       switch (ap->a_vp->v_type) {
+       vp = ap->a_vp;
+       dev = NODEV;
+       simple_lock(&vp->v_interlock);
+       if ((vp->v_flag & VXLOCK) == 0 && vp->v_specinfo) {
+               dev = vp->v_rdev;
+       }
+       simple_unlock(&vp->v_interlock);
+       if (dev == NODEV) {
+               return ENXIO;
+       }
+
+       switch (vp->v_type) {
 
        case VCHR:
                cdev = cdevsw_lookup(dev);