Add a strict allocator that does canaries and various other things, for

platforms which don't have Valgrind.

Valgrind is still the better choice on platforms which support it.

svn path=/trunk/; revision=46828

epan/CMakeLists.txt

@@ -1355,6 +1355,7 @@ set(WMEM_FILES
 	wmem/wmem_core.c
 	wmem/wmem_allocator_block.c
 	wmem/wmem_allocator_simple.c
+	wmem/wmem_allocator_strict.c
 	wmem/wmem_scopes.c
 	wmem/wmem_slab.c
 	wmem/wmem_slist.c

epan/wmem/Makefile.common

@@ -27,6 +27,7 @@ LIBWMEM_SRC =				\
 	wmem_core.c    			\
 	wmem_allocator_block.c		\
 	wmem_allocator_simple.c		\
+	wmem_allocator_strict.c		\
 	wmem_scopes.c			\
 	wmem_slab.c			\
 	wmem_slist.c			\
@@ -40,6 +41,7 @@ LIBWMEM_INCLUDES =			\
 	wmem_allocator.h       		\
 	wmem_allocator_block.h		\
 	wmem_allocator_simple.h		\
+	wmem_allocator_strict.h		\
 	wmem_scopes.h			\
 	wmem_slab.h			\
 	wmem_slist.h			\

epan/wmem/wmem_allocator_strict.c

@@ -0,0 +1,180 @@
+/* wmem_allocator_strict.c
+ * Wireshark Memory Manager Strict Allocator
+ * Copyright 2012, Evan Huus <eapache@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <string.h>
+
+#include <glib.h>
+
+#include "wmem_core.h"
+#include "wmem_allocator.h"
+
+/* In this allocator, we do everything we can to catch invalid memory accesses.
+ * This includes using canaries (what Valgrind calls redzones) and
+ * filling allocated and freed memory with garbage. Valgrind is still the
+ * better tool on the platforms where it is available - use it instead if
+ * possible.
+ */
+
+#define WMEM_CANARY_SIZE  16
+#define WMEM_CANARY_VALUE 0x8E
+
+#define WMEM_PREFILL  0xA1
+#define WMEM_POSTFILL 0x1A
+
+typedef struct _wmem_strict_allocator_block_t {
+    /* Simple manual singly-linked list of allocations */
+    struct _wmem_strict_allocator_block_t *next;
+
+    /* Just the length of real_data, not counting the canaries */
+    gsize   data_len;
+
+    guint8 *leading_canary;
+    guint8 *real_data;
+    guint8 *trailing_canary;
+} wmem_strict_allocator_block_t;
+
+typedef struct _wmem_strict_allocator_t {
+    wmem_strict_allocator_block_t *block_list;
+} wmem_strict_allocator_t;
+
+static void *
+wmem_strict_alloc(void *private_data, const size_t size)
+{
+    wmem_strict_allocator_t       *allocator;
+    wmem_strict_allocator_block_t *block;
+    
+    allocator = (wmem_strict_allocator_t*) private_data;
+
+    block = g_new(wmem_strict_allocator_block_t, 1);
+
+    block->data_len        = size;
+    block->leading_canary  = g_malloc(block->data_len + (2 * WMEM_CANARY_SIZE));
+    block->real_data       = block->leading_canary + WMEM_CANARY_SIZE;
+    block->trailing_canary = block->real_data + block->data_len;
+    block->next            = allocator->block_list;
+    allocator->block_list  = block;
+
+    memset(block->leading_canary,  WMEM_CANARY_VALUE, WMEM_CANARY_SIZE);
+    memset(block->real_data,       WMEM_PREFILL,      block->data_len);
+    memset(block->trailing_canary, WMEM_CANARY_VALUE, WMEM_CANARY_SIZE);
+    
+    return block->real_data;
+}
+
+static void
+wmem_strict_real_check_canaries(wmem_strict_allocator_t *allocator)
+{
+    guint i;
+    wmem_strict_allocator_block_t *block;
+
+    block = allocator->block_list;
+
+    while (block) {
+        for (i=0; i<WMEM_CANARY_SIZE; i++) {
+            g_assert(block->leading_canary[i]  == WMEM_CANARY_VALUE);
+            g_assert(block->trailing_canary[i] == WMEM_CANARY_VALUE);
+        }
+        block = block->next;
+    }
+}
+
+void
+wmem_strict_check_canaries(wmem_allocator_t *allocator)
+{
+    /* XXX: Should this be a g_assert() instead? This is more of a general API
+     * issue - should allocator-specific functions be safe to call with an
+     * allocator of the wrong type or not? And how should they interact with the
+     * WIRESHARK_DEBUG_WMEM_OVERRIDE environment variable? */
+    if (allocator->type != WMEM_ALLOCATOR_STRICT) {
+        return;
+    }
+
+    wmem_strict_real_check_canaries(allocator->private_data);
+}
+
+static void
+wmem_strict_free_all(void *private_data)
+{
+    wmem_strict_allocator_t       *allocator;
+    wmem_strict_allocator_block_t *block, *tmp;
+
+    allocator = (wmem_strict_allocator_t*) private_data;
+
+    wmem_strict_real_check_canaries(allocator);
+
+    block = allocator->block_list;
+
+    while (block) {
+        memset(block->real_data, WMEM_POSTFILL, block->data_len);
+
+        g_free(block->leading_canary);
+
+        tmp = block;
+        block = block->next;
+        g_free(tmp);
+    }
+
+    allocator->block_list = NULL;
+}
+
+static void
+wmem_strict_allocator_destroy(wmem_allocator_t *allocator)
+{
+    g_free(allocator->private_data);
+    g_free(allocator);
+}
+
+wmem_allocator_t *
+wmem_strict_allocator_new(void)
+{
+    wmem_allocator_t        *allocator;
+    wmem_strict_allocator_t *strict_allocator;
+
+    allocator        = g_new(wmem_allocator_t, 1);
+    strict_allocator = g_new(wmem_strict_allocator_t, 1);
+
+    allocator->alloc        = &wmem_strict_alloc;
+    allocator->free_all     = &wmem_strict_free_all;
+    allocator->destroy      = &wmem_strict_allocator_destroy;
+    allocator->private_data = (void*) strict_allocator;
+
+    strict_allocator->block_list = NULL;
+
+    return allocator;
+}
+
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */

epan/wmem/wmem_allocator_strict.h

@@ -0,0 +1,58 @@
+/* wmem_allocator_strict.h
+ * Definitions for the Wireshark Memory Manager Strict Allocator
+ * Copyright 2012, Evan Huus <eapache@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef __WMEM_ALLOCATOR_STRICT_H__
+#define __WMEM_ALLOCATOR_STRICT_H__
+
+#include "wmem_core.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+wmem_allocator_t *
+wmem_strict_allocator_new(void);
+
+void
+wmem_strict_check_canaries(wmem_allocator_t *allocator);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* __WMEM_ALLOCATOR_STRICT_H__ */
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */

epan/wmem/wmem_core.c

@@ -32,6 +32,7 @@
 #include "wmem_allocator.h"
 #include "wmem_allocator_simple.h"
 #include "wmem_allocator_block.h"
+#include "wmem_allocator_strict.h"
 
 void *
 wmem_alloc(wmem_allocator_t *allocator, const size_t size)
@@ -84,6 +85,9 @@ wmem_allocator_new(const wmem_allocator_type_t type)
     else if (strncmp(override, "block", strlen("block")) == 0) {
         real_type = WMEM_ALLOCATOR_BLOCK;
     }
+    else if (strncmp(override, "strict", strlen("strict")) == 0) {
+        real_type = WMEM_ALLOCATOR_STRICT;
+    }
     else {
         g_warning("Unrecognized wmem override");
         real_type = type;
@@ -96,6 +100,9 @@ wmem_allocator_new(const wmem_allocator_type_t type)
         case WMEM_ALLOCATOR_BLOCK:
             allocator = wmem_block_allocator_new();
             break;
+        case WMEM_ALLOCATOR_STRICT:
+            allocator = wmem_strict_allocator_new();
+            break;
         default:
             g_assert_not_reached();
             /* This is necessary to squelch MSVC errors; is there

epan/wmem/wmem_core.h

@@ -34,7 +34,8 @@ extern "C" {
 
 typedef enum _wmem_allocator_type_t {
     WMEM_ALLOCATOR_SIMPLE,
-    WMEM_ALLOCATOR_BLOCK
+    WMEM_ALLOCATOR_BLOCK,
+    WMEM_ALLOCATOR_STRICT
 } wmem_allocator_type_t;
 
 struct _wmem_allocator_t;