[src/trunk]: src/sys/uvm prevent kernel from writing more than userland passed.

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

details:   https://anonhg.NetBSD.org/src/rev/6890a7550934
branches:  trunk
changeset: 772352:6890a7550934
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Dec 30 19:01:07 2011 +0000

description:
prevent kernel from writing more than userland passed.

diffstat:

 sys/uvm/uvm_meter.c |  6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diffs (27 lines):

diff -r 38e4867826fe -r 6890a7550934 sys/uvm/uvm_meter.c
--- a/sys/uvm/uvm_meter.c       Fri Dec 30 18:20:46 2011 +0000
+++ b/sys/uvm/uvm_meter.c       Fri Dec 30 19:01:07 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_meter.c,v 1.57 2011/11/13 02:10:40 christos Exp $  */
+/*     $NetBSD: uvm_meter.c,v 1.58 2011/12/30 19:01:07 christos Exp $  */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -36,7 +36,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_meter.c,v 1.57 2011/11/13 02:10:40 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_meter.c,v 1.58 2011/12/30 19:01:07 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -180,6 +180,8 @@
        node = *rnode;
        node.sysctl_data = &u;
        node.sysctl_size = sizeof(u);
+       if (oldlenp)
+               node.sysctl_size = min(*oldlenp, node.sysctl_size);
        return (sysctl_lookup(SYSCTLFN_CALL(&node)));
 }