[src/trunk]: src/common/lib/libc/gen Add code to protect the ptree from multi...

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

details:   https://anonhg.NetBSD.org/src/rev/361dc60fa4ea
branches:  trunk
changeset: 780185:361dc60fa4ea
user:      matt <matt%NetBSD.org@localhost>
date:      Sat Jul 14 18:16:54 2012 +0000

description:
Add code to protect the ptree from multiple insertions of the same node.

diffstat:

 common/lib/libc/gen/ptree.c |  18 +++++++++++++++---
 1 files changed, 15 insertions(+), 3 deletions(-)

diffs (53 lines):

diff -r 3677c027e9df -r 361dc60fa4ea common/lib/libc/gen/ptree.c
--- a/common/lib/libc/gen/ptree.c       Sat Jul 14 17:12:27 2012 +0000
+++ b/common/lib/libc/gen/ptree.c       Sat Jul 14 18:16:54 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ptree.c,v 1.7 2012/07/13 01:15:27 matt Exp $   */
+/*     $NetBSD: ptree.c,v 1.8 2012/07/14 18:16:54 matt Exp $   */
 
 /*-
  * Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -40,7 +40,7 @@
 #include <sys/types.h>
 #include <sys/systm.h>
 #include <lib/libkern/libkern.h>
-__KERNEL_RCSID(0, "$NetBSD: ptree.c,v 1.7 2012/07/13 01:15:27 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ptree.c,v 1.8 2012/07/14 18:16:54 matt Exp $");
 #else
 #include <stddef.h>
 #include <stdint.h>
@@ -53,7 +53,7 @@
 #else
 #define        KASSERT(e)      do { } while (/*CONSTCOND*/ 0)
 #endif
-__RCSID("$NetBSD: ptree.c,v 1.7 2012/07/13 01:15:27 matt Exp $");
+__RCSID("$NetBSD: ptree.c,v 1.8 2012/07/14 18:16:54 matt Exp $");
 #endif /* _KERNEL || _STANDALONE */
 
 #ifdef _LIBC
@@ -459,6 +459,12 @@
        pt_insertdata_t id;
 
        /*
+        * If this node already exists in the tree, return failure.
+        */
+       if (target == PT_NODE(pt->pt_root))
+               return false;
+
+       /*
         * We need a leaf so we can match against.  Until we get a leaf
         * we having nothing to test against.
         */
@@ -480,6 +486,12 @@
                id.id_node = *id.id_insertp;
 
                /*
+                * If this node already exists in the tree, return failure.
+                */
+               if (target == ptn)
+                       return false;
+
+               /*
                 * If we hit a leaf, try to insert target at leaf.  We could
                 * have inlined ptree_insert_leaf here but that would have
                 * made this routine much harder to understand.  Trust the