[src/trunk]: src/sys/kern PR/45736: Michael van Elst: setting kern.maxvnodes ...

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

details:   https://anonhg.NetBSD.org/src/rev/95404f116f1d
branches:  trunk
changeset: 772227:95404f116f1d
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Dec 25 02:23:09 2011 +0000

description:
PR/45736: Michael van Elst: setting kern.maxvnodes may lock up
Clamp the number of elements to the max possible if exceeded

diffstat:

 sys/kern/subr_hash.c |  10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)

diffs (33 lines):

diff -r 01be83f30225 -r 95404f116f1d sys/kern/subr_hash.c
--- a/sys/kern/subr_hash.c      Sun Dec 25 01:05:44 2011 +0000
+++ b/sys/kern/subr_hash.c      Sun Dec 25 02:23:09 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_hash.c,v 1.3 2008/05/05 17:11:17 ad Exp $ */
+/*     $NetBSD: subr_hash.c,v 1.4 2011/12/25 02:23:09 christos Exp $   */
 
 /*
  * Copyright (c) 1982, 1986, 1991, 1993
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_hash.c,v 1.3 2008/05/05 17:11:17 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_hash.c,v 1.4 2011/12/25 02:23:09 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/kmem.h>
@@ -58,9 +58,13 @@
        TAILQ_HEAD(, generic) *hashtbl_tailq;
        size_t esize;
        void *p;
-
        if (elements == 0)
                panic("hashinit: bad cnt");
+
+#define MAXELEMENTS (1U << ((sizeof(elements) * NBBY) - 1))
+       if (elements > MAXELEMENTS)
+               elements = MAXELEMENTS;
+
        for (hashsize = 1; hashsize < elements; hashsize <<= 1)
                continue;