[src/trunk]: src/usr.bin/config - Instead of checking the recursion level bef...

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

details:   https://anonhg.NetBSD.org/src/rev/1001ff191a53
branches:  trunk
changeset: 828042:1001ff191a53
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Nov 24 23:42:36 2017 +0000

description:
- Instead of checking the recursion level before we recurse, check in on
  function entry.
- Always decrement the level and reset levelparent on exit.

diffstat:

 usr.bin/config/main.c |  49 +++++++++++++++++++++++++------------------------
 1 files changed, 25 insertions(+), 24 deletions(-)

diffs (108 lines):

diff -r e485b5e9ff34 -r 1001ff191a53 usr.bin/config/main.c
--- a/usr.bin/config/main.c     Fri Nov 24 21:30:43 2017 +0000
+++ b/usr.bin/config/main.c     Fri Nov 24 23:42:36 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: main.c,v 1.94 2017/11/18 18:39:16 christos Exp $       */
+/*     $NetBSD: main.c,v 1.95 2017/11/24 23:42:36 christos Exp $       */
 
 /*
  * Copyright (c) 1992, 1993
@@ -45,7 +45,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: main.c,v 1.94 2017/11/18 18:39:16 christos Exp $");
+__RCSID("$NetBSD: main.c,v 1.95 2017/11/24 23:42:36 christos Exp $");
 
 #ifndef MAKE_BOOTSTRAP
 #include <sys/cdefs.h>
@@ -1868,27 +1868,30 @@
        return 0;
 }
 
-static int
-is_orphan_loop(const struct devbase *d, const struct devbase *p)
-{
+static struct devbase root;
 
-       for (; p && d != p; p = p->d_levelparent)
-               continue;
-       return d == p;
-}
-
-static void
+static int
 addlevelparent(struct devbase *d, struct devbase *parent)
 {
        struct devbase *p;
 
-       if (d->d_levelparent)
-               return;
+       if (d == parent) {
+               if (d->d_level++ > 1)
+                       return 0;
+               return 1;
+       }
+
+       if (d->d_levelparent) {
+               if (d->d_level++ > 1)
+                       return 0;
+               return 1;
+       }
 
        for (p = parent; p != NULL; p = p->d_levelparent)
-               if (d == p)
-                       return;
-       d->d_levelparent = p;
+               if (d == p && d->d_level++ > 1)
+                       return 0;
+       d->d_levelparent = p ? p : &root; 
+       return 1;
 }
 
 static void
@@ -1902,7 +1905,8 @@
        struct pspec *p;
        int active = 0;
 
-       addlevelparent(d, parent);
+       if (!addlevelparent(d, parent))
+               return;
 
        /*
         * A pseudo-device will always attach at root, and if it has an
@@ -1970,7 +1974,7 @@
                 * If we've been there but have made no change, stop.
                 */
                if (seen && active != DEVI_ACTIVE)
-                       return;
+                       goto out;
                if (active != DEVI_ACTIVE) {
                        struct cdd_params cdd = { d, at, parent };
                        /* Look for a matching dead devi */
@@ -1990,22 +1994,19 @@
                                CFGDBG(5, "`%s' at '%s' ignored", d->d_name,
                                    parent ? parent->d_name : "(root)");
 
-                       } else
-                               return;
+                       }
                }
        }
 
        for (al = d->d_attrs; al != NULL; al = al->al_next) {
                a = al->al_this;
                for (nv1 = a->a_devs; nv1 != NULL; nv1 = nv1->nv_next) {
-                       if (is_orphan_loop(nv1->nv_ptr, d)) {
-                               if (d->d_level++ > 1)
-                                       continue;
-                       }
                        do_kill_orphans(nv1->nv_ptr, a, d, active);
                }
        }
+out:
        d->d_levelparent = NULL;
+       d->d_level--;
 }
 
 static int