Original sources modified for use in kernel modules.

Bug in function 'memdebug_cleanup' corrected (access just freed struct)

git-svn-id: https://parma.zhaw.ch/svn/csnippets@5 bb4c1ae6-6eb5-4d93-a66e-2307d6765a9c

2 files changed, 292 insertions, 0 deletions

diff --git a/memdebug_kernel/memdebug.c b/memdebug_kernel/memdebug.c
new file mode 100644
index 0000000..cdc16fb
--- /dev/null
+++ b/memdebug_kernel/memdebug.c
@@ -0,0 +1,210 @@
+/*
+ * memdebug - A simple kmalloc/kfree debugger
+ *
+ * This can essentially be useful on embedded systems platforms where tools such
+ * as valgrind are not available.
+ *
+ * Copyright (c) 2010 Zurich University of Applied Sciences
+ * Copyright (c) 2010 Tobias Klauser <tklauser@distanz.ch>
+ * 
+ * HISTORY
+ * 12.11.2010	gram	Original sources modified for use in kernel modules.
+ * 						Sections (comment blocks) added.
+ * 						Bug in function 'memdebug_cleanup' corrected (access
+ * 						just freed struct)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/*******************************************************************************
+   Includes
+*******************************************************************************/
+
+#include <linux/types.h>
+#include <linux/slab.h>
+
+/*******************************************************************************
+   Definitions
+*******************************************************************************/
+
+/* define/undef to enable tracing of errors */
+//#define MEMDEBUG_TRACE
+#include "memdebug.h"
+
+/*******************************************************************************
+   Structs, Types and Enums
+*******************************************************************************/
+
+struct memdebug_heap_item {
+	struct memdebug_heap_item *next;
+
+	void *addr;
+	size_t size;
+
+	const char *func;
+	const char *file;
+	unsigned int line;
+
+	const char *freed_func;
+	const char *freed_file;
+	unsigned int freed_line;
+};
+
+/*******************************************************************************
+   Module Global Variable
+*******************************************************************************/
+
+static struct memdebug_heap_item *heap_head = NULL;
+static struct memdebug_heap_item *heap_tail = NULL;
+
+/*******************************************************************************
+   Public Functions
+*******************************************************************************/
+
+void memdebug_start(void)
+{
+	/* Empty for now */
+}
+
+void memdebug_cleanup(void)
+{
+	struct memdebug_heap_item *hi, *next;
+
+	for (hi = heap_head; hi != NULL; hi = next) {
+		if (hi->addr != NULL){
+			kfree(hi->addr);
+		}
+		next = hi->next;
+		kfree(hi);
+	}
+
+	heap_head = NULL;
+	heap_tail = NULL;
+}
+
+void *__memdebug_malloc(size_t size, int priority, const char *func,
+                        const char *file, const unsigned int line)
+{
+	void *ret;
+	struct memdebug_heap_item *hi = kmalloc(sizeof(struct memdebug_heap_item), priority);
+
+	if (!hi)
+		goto out_err;
+
+	ret = kmalloc(size, priority);
+	if (!ret) {
+		kfree(hi);
+		goto out_err;
+	}
+
+	hi->next = NULL;
+	hi->addr = ret;
+	hi->size = size;
+	hi->func = func;
+	hi->file = file;
+	hi->line = line;
+	hi->freed_func = NULL;
+	hi->freed_file = NULL;
+	hi->line = 0;
+
+	if (!heap_head)
+		heap_head = hi;
+	if (heap_tail)
+		heap_tail->next = hi;
+	heap_tail = hi;
+
+	return ret;
+
+out_err:
+	memdebug_trace("malloc failed (%s:%d:%s)", file, line, func);
+	return NULL;
+}
+
+void __memdebug_free(void *ptr, const char *func,
+                     const char *file, const unsigned int line)
+{
+	struct memdebug_heap_item *hi, *prev;
+
+	if (!ptr) {
+		memdebug_trace("trying to free NULL pointer (%s:%d:%s)", file, line, func);
+		return;
+	}
+
+	for (hi = heap_head, prev = NULL; hi; prev = hi, hi = hi->next)
+		if (hi->addr == ptr)
+			break;
+
+	if (!hi) {
+		memdebug_trace("no memory allocated at %p (%s:%d:%s)", ptr, file, line, func);
+		return;
+	}
+
+	if (hi->freed_func) {
+		memdebug_trace("double free at %p (%s:%d:%s)\nalready freed by %s:%d:%s",
+				ptr, file, line, func, hi->freed_file, hi->freed_line, hi->freed_func);
+		return;
+	}
+
+	hi->freed_func = func;
+	hi->freed_file = file;
+	hi->freed_line = line;
+
+	/* Free the memory but keep the memdebug information */
+	kfree(hi->addr);
+	hi->addr = NULL;
+}
+
+void memdebug_report(bool report_free)
+{
+	struct memdebug_heap_item *hi;
+	size_t total_size = 0;
+	size_t still_allocated = 0;
+
+	printk(KERN_DEBUG "\n\n*** Reporting allocated/freed memory ***\n");
+	for (hi = heap_head; hi; hi = hi->next) {
+		if (hi->addr) {
+			printk(KERN_DEBUG "  IN USE  %zu bytes at %p (%s:%d:%s)\n",
+					hi->size, hi->addr, hi->file, hi->line, hi->func);
+			still_allocated += hi->size;
+		} else if (report_free) {
+			printk(KERN_DEBUG "  FREE    %zu bytes at %p (%s:%d:%s)\n",
+					hi->size, hi->addr, hi->file, hi->line, hi->func);
+		}
+		total_size += hi->size;
+	}
+	printk(KERN_DEBUG "Total size: %zu bytes, %zu bytes still allocated\n\n",
+			total_size, still_allocated);
+}
+
+void memdebug_report_brief(void)
+{
+	struct memdebug_heap_item *hi;
+	size_t total_size = 0;
+	size_t still_allocated = 0;
+
+	printk(KERN_DEBUG "\n\n*** Reporting allocated/freed memory ***\n");
+	for (hi = heap_head; hi; hi = hi->next) {
+		if (hi->addr) {
+			still_allocated += hi->size;
+		}
+		total_size += hi->size;
+	}
+	printk(KERN_DEBUG "Total size: %zu bytes, %zu bytes still allocated\n\n",
+			total_size, still_allocated);
+}
diff --git a/memdebug_kernel/memdebug.h b/memdebug_kernel/memdebug.h
new file mode 100644
index 0000000..ff9ab48
--- /dev/null
+++ b/memdebug_kernel/memdebug.h
@@ -0,0 +1,82 @@
+/*
+ * memdebug - A simple malloc/free debugger
+ *
+ * This can essentially be useful on embedded systems platforms where tools such
+ * as valgrind are not available.
+ *
+ * Copyright (c) 2010 Zurich University of Applied Sciences
+ * Copyright (c) 2010 Tobias Klauser <tklauser@distanz.ch>
+ *
+ * HISTORY
+ * 12.11.2010	gram	Original sources modified for use in kernel modules.
+ * 						Sections (comment blocks) added.
+ * 						Prototype for function 'memdebug_cleanup' added
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MEMDEBUG_H_
+#define MEMDEBUG_H_
+
+/*******************************************************************************
+   Includes
+*******************************************************************************/
+
+
+/*******************************************************************************
+   Definitions
+*******************************************************************************/
+
+
+/*******************************************************************************
+   Structs, Types and Enums
+*******************************************************************************/
+
+
+/*******************************************************************************
+   Macros
+*******************************************************************************/
+
+#ifdef MEMDEBUG_TRACE
+# define memdebug_trace(fmt, args...) \
+	({ \
+	 printk(KERN_DEBUG "*** " fmt " ***\n", ##args); \
+	 })
+#else
+# define memdebug_trace(fmt, args...)
+#endif
+
+#define memdebug_malloc(size, priority) \
+	__memdebug_malloc(size, priority, __func__, __FILE__, __LINE__)
+#define memdebug_free(ptr) \
+	__memdebug_free(ptr, __func__, __FILE__, __LINE__)
+
+/*******************************************************************************
+   Prototypes for external functions
+*******************************************************************************/
+
+void memdebug_cleanup(void);
+void *__memdebug_malloc(size_t size, int priority, const char *func,
+                        const char *file, const unsigned int line);
+void __memdebug_free(void *ptr, const char *func,
+                   const char *file, const unsigned int line);
+void memdebug_report(bool report_free);
+void memdebug_report_brief(void);
+
+#endif /* MEMDEBUG_H_ */