[src/trunk]: src/sys/miscfs/specfs If we attempt to autoload a driver module, ...

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

details:   https://anonhg.NetBSD.org/src/rev/c1b601c8b671
branches:  trunk
changeset: 342460:c1b601c8b671
user:      pgoyette <pgoyette%NetBSD.org@localhost>
date:      Tue Dec 22 23:54:37 2015 +0000

description:
If we attempt to autoload a driver module, make sure we return an error
if it fails.  Otherwise we might end up calling a builtin-but-disabled
driver module and that can generate all sorts of issues...

diffstat:

 sys/miscfs/specfs/spec_vnops.c |  21 ++++++++++++++++-----
 1 files changed, 16 insertions(+), 5 deletions(-)

diffs (50 lines):

diff -r 25cfe5dd478f -r c1b601c8b671 sys/miscfs/specfs/spec_vnops.c
--- a/sys/miscfs/specfs/spec_vnops.c    Tue Dec 22 23:35:21 2015 +0000
+++ b/sys/miscfs/specfs/spec_vnops.c    Tue Dec 22 23:54:37 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: spec_vnops.c,v 1.157 2015/12/08 20:36:15 christos Exp $        */
+/*     $NetBSD: spec_vnops.c,v 1.158 2015/12/22 23:54:37 pgoyette Exp $        */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -58,7 +58,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.157 2015/12/08 20:36:15 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.158 2015/12/22 23:54:37 pgoyette Exp $");
 
 #include <sys/param.h>
 #include <sys/proc.h>
@@ -573,7 +573,12 @@
                                break;
                        
                        /* Try to autoload device module */
-                       (void) module_autoload(name, MODULE_CLASS_DRIVER);
+                       error = module_autoload(name, MODULE_CLASS_DRIVER);
+                       if (error != 0) {
+                               error = ENXIO;
+                               break;
+                       }
+
                } while (gen != module_gen);
 
                vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
@@ -624,9 +629,15 @@
                        VOP_UNLOCK(vp);
 
                         /* Try to autoload device module */
-                       (void) module_autoload(name, MODULE_CLASS_DRIVER);
+                       error = module_autoload(name, MODULE_CLASS_DRIVER);
+
+                       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+
+                       if (error != 0) {
+                               error = ENXIO;
+                               break;
+                       }
                        
-                       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
                } while (gen != module_gen);
 
                break;