[src/trunk]: src/sys/compat/netbsd32 Fix cases where count <= 0 (thanks to Ma...

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

details:   https://anonhg.NetBSD.org/src/rev/6a365d5a14fe
branches:  trunk
changeset: 795986:6a365d5a14fe
user:      manu <manu%NetBSD.org@localhost>
date:      Thu May 15 18:25:35 2014 +0000

description:
Fix cases where count <= 0 (thanks to Maxime Villard for raising this)

diffstat:

 sys/compat/netbsd32/netbsd32_netbsd.c |  15 ++++++++-------
 1 files changed, 8 insertions(+), 7 deletions(-)

diffs (50 lines):

diff -r 06c3a4eec8ff -r 6a365d5a14fe sys/compat/netbsd32/netbsd32_netbsd.c
--- a/sys/compat/netbsd32/netbsd32_netbsd.c     Thu May 15 17:05:15 2014 +0000
+++ b/sys/compat/netbsd32/netbsd32_netbsd.c     Thu May 15 18:25:35 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: netbsd32_netbsd.c,v 1.186 2014/04/30 17:23:45 njoly Exp $      */
+/*     $NetBSD: netbsd32_netbsd.c,v 1.187 2014/05/15 18:25:35 manu Exp $       */
 
 /*
  * Copyright (c) 1998, 2001, 2008 Matthew R. Green
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_netbsd.c,v 1.186 2014/04/30 17:23:45 njoly Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_netbsd.c,v 1.187 2014/05/15 18:25:35 manu Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_ddb.h"
@@ -1763,6 +1763,12 @@
        int i, error = 0;
        size_t ksep_len;
 
+       if (count < 0)
+               return EINVAL;
+
+       if (count == 0 || uvmexp.nswapdev == 0)
+               return 0;
+
        /* Make sure userland cannot exhaust kernel memory */
        if ((size_t)count > (size_t)uvmexp.nswapdev)
                count = uvmexp.nswapdev;
@@ -1774,9 +1780,6 @@
        uvm_swap_stats(SWAP_STATS, ksep, count, retval);
        count = *retval;
 
-       if (count < 1)
-               goto out;
-
        for (i = 0; i < count; i++) {
                se32.se_dev = ksep[i].se_dev;
                se32.se_flags = ksep[i].se_flags;
@@ -1791,8 +1794,6 @@
                        break;
        }
 
-       
-out:
        kmem_free(ksep, ksep_len);
 
        return error;