[src/trunk]: src/sys/kern Clobber the size when freeing a buffer. This way, i...

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

details:   https://anonhg.NetBSD.org/src/rev/7618eec6ab0d
branches:  trunk
changeset: 448531:7618eec6ab0d
user:      maxv <maxv%NetBSD.org@localhost>
date:      Mon Feb 04 15:13:54 2019 +0000

description:
Clobber the size when freeing a buffer. This way, if the same buffer gets
freed twice, the second size check will fire.

diffstat:

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

diffs (27 lines):

diff -r f3e38751576f -r 7618eec6ab0d sys/kern/subr_kmem.c
--- a/sys/kern/subr_kmem.c      Mon Feb 04 15:07:34 2019 +0000
+++ b/sys/kern/subr_kmem.c      Mon Feb 04 15:13:54 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_kmem.c,v 1.72 2018/12/23 12:15:01 maxv Exp $      */
+/*     $NetBSD: subr_kmem.c,v 1.73 2019/02/04 15:13:54 maxv Exp $      */
 
 /*-
  * Copyright (c) 2009-2015 The NetBSD Foundation, Inc.
@@ -92,7 +92,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.72 2018/12/23 12:15:01 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.73 2019/02/04 15:13:54 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_kmem.h"
@@ -549,6 +549,8 @@
                panic("kmem_free(%p, %zu) != allocated size %zu",
                    (const uint8_t *)p + SIZE_SIZE, sz, hsz);
        }
+
+       hd->size = -1;
 }
 #endif /* defined(KMEM_SIZE) */