[src/trunk]: src/sys/kern Enable KMEM_REDZONE on DIAGNOSTIC. It will try to c...

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

details:   https://anonhg.NetBSD.org/src/rev/9f5927c7fd03
branches:  trunk
changeset: 330799:9f5927c7fd03
user:      maxv <maxv%NetBSD.org@localhost>
date:      Tue Jul 22 07:38:41 2014 +0000

description:
Enable KMEM_REDZONE on DIAGNOSTIC. It will try to catch overflows.

No comment on tech-kern@

diffstat:

 sys/kern/subr_kmem.c |  22 ++++++++++++++++------
 1 files changed, 16 insertions(+), 6 deletions(-)

diffs (58 lines):

diff -r 58f7be00f05b -r 9f5927c7fd03 sys/kern/subr_kmem.c
--- a/sys/kern/subr_kmem.c      Tue Jul 22 04:55:51 2014 +0000
+++ b/sys/kern/subr_kmem.c      Tue Jul 22 07:38:41 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_kmem.c,v 1.59 2014/07/03 08:43:49 maxv Exp $      */
+/*     $NetBSD: subr_kmem.c,v 1.60 2014/07/22 07:38:41 maxv Exp $      */
 
 /*-
  * Copyright (c) 2009 The NetBSD Foundation, Inc.
@@ -65,13 +65,23 @@
  *     Prefix each allocations with a fixed-sized, aligned header and record
  *     the exact user-requested allocation size in it. When freeing, compare
  *     it with kmem_free's "size" argument.
- */
-
-/*
+ *
  * KMEM_REDZONE: detect overrun bugs.
  *     Add a 2-byte pattern (allocate one more memory chunk if needed) at the
  *     end of each allocated buffer. Check this pattern on kmem_free.
  *
+ * These options are enabled on DIAGNOSTIC.
+ *
+ *  |CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|CHUNK|
+ *  +-----+-----+-----+-----+-----+-----+-----+-----+-----+---+-+--+--+
+ *  |/////|     |     |     |     |     |     |     |     |   |*|**|UU|
+ *  |/HSZ/|     |     |     |     |     |     |     |     |   |*|**|UU|
+ *  |/////|     |     |     |     |     |     |     |     |   |*|**|UU|
+ *  +-----+-----+-----+-----+-----+-----+-----+-----+-----+---+-+--+--+
+ *  |Size |    Buffer usable by the caller (requested size)   |RedZ|Unused\
+ */
+
+/*
  * KMEM_POISON: detect modify-after-free bugs.
  *     Fill freed (in the sense of kmem_free) memory with a garbage pattern.
  *     Check the pattern on allocation.
@@ -90,7 +100,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.59 2014/07/03 08:43:49 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_kmem.c,v 1.60 2014/07/22 07:38:41 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/callback.h>
@@ -168,11 +178,11 @@
 
 #if defined(DIAGNOSTIC) && defined(_HARDKERNEL)
 #define        KMEM_SIZE
+#define        KMEM_REDZONE
 #endif /* defined(DIAGNOSTIC) */
 
 #if defined(DEBUG) && defined(_HARDKERNEL)
 #define        KMEM_POISON
-#define        KMEM_REDZONE
 #define        KMEM_GUARD
 #endif /* defined(DEBUG) */