This is a new version (0.10) of the kernel memory leak detector. See
the Documentation/kmemleak.txt file for a more detailed
description. The patches are downloadable from (the whole patch or the
broken-out series):
http://homepage.ntlworld.com/cmarinas/kmemleak/patch-2.6.18-rc6-kmemleak-0.10.bz2
http://homepage.ntlworld.com/cmarinas/kmemleak/broken-out/patches-kmemleak-0.10.tar.bz2
What's new in this version:
- replaced the pointers radix tree with a hash table to avoid the
locking dependencies caused by the radix tree memory allocations
- fixed locking dependency problems by no longer holding the
memleak_lock when allocating/freeing memory from kmemleak and also
using RCU
- changed the naming of tracked memory blocks from "pointer" to
"object"
- code clean-up
To do:
- testing on a wider range of platforms and configurations
- support for ioremap tracking (once the generic ioremap patches are
merged)
- eliminate the task stacks scanning (if possible, by marking the
allocated blocks as temporary until the return to user-space -
Ingo's suggestion)
- precise type identification (after first assessing the efficiency of
the current method as it requires changes to the kernel API)
--
Catalin
From: Catalin Marinas <[email protected]>
This patch adds the base support for the kernel memory leak detector. It
traces the memory allocation/freeing in a way similar to the Boehm's
conservative garbage collector, the difference being that the orphan
pointers are not freed but only shown in /proc/memleak. Enabling this
feature would introduce an overhead to memory allocations.
Signed-off-by: Catalin Marinas <[email protected]>
---
include/linux/kernel.h | 7
include/linux/memleak.h | 111 +++
init/main.c | 3
lib/Kconfig.debug | 90 +++
mm/Makefile | 2
mm/memleak.c | 1518 +++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 1728 insertions(+), 3 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 851aa1b..4f61cb5 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -13,6 +13,7 @@ #include <linux/stddef.h>
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/bitops.h>
+#include <linux/memleak.h>
#include <asm/byteorder.h>
#include <asm/bug.h>
@@ -292,9 +293,13 @@ #define max_t(type,x,y) \
* @member: the name of the member within the struct.
*
*/
-#define container_of(ptr, type, member) ({ \
+#define __container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
+#define container_of(ptr, type, member) ({ \
+ DECLARE_MEMLEAK_OFFSET(container_of, type, member); \
+ __container_of(ptr, type, member); \
+})
/*
* Check at compile time that something is of a particular type.
diff --git a/include/linux/memleak.h b/include/linux/memleak.h
new file mode 100644
index 0000000..39669bf
--- /dev/null
+++ b/include/linux/memleak.h
@@ -0,0 +1,111 @@
+/*
+ * include/linux/memleak.h
+ *
+ * Copyright (C) 2006 ARM Limited
+ * Written by Catalin Marinas <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __MEMLEAK_H
+#define __MEMLEAK_H
+
+#include <linux/stddef.h>
+
+struct memleak_offset {
+ unsigned long type_id;
+ unsigned long member_type_id;
+ unsigned long offset;
+};
+
+/* type id approximation */
+#define ml_guess_typeid(size) ((unsigned long)(size))
+#define ml_typeid(type) ml_guess_typeid(sizeof(type))
+#define ml_sizeof(typeid) ((size_t)(typeid))
+
+#ifdef CONFIG_DEBUG_MEMLEAK
+
+/* if offsetof(type, member) is not a constant known at compile time,
+ * just use 0 instead since we cannot add it to the
+ * .init.memleak_offsets section
+ */
+#define memleak_offsetof(type, member) \
+ (__builtin_constant_p(offsetof(type, member)) ? \
+ offsetof(type, member) : 0)
+
+#define DECLARE_MEMLEAK_OFFSET(name, type, member) \
+ static const struct memleak_offset \
+ __attribute__ ((__section__ (".init.memleak_offsets"))) \
+ __attribute_used__ __memleak_offset__##name = { \
+ ml_typeid(type), \
+ ml_typeid(typeof(((type *)0)->member)), \
+ memleak_offsetof(type, member) \
+ }
+
+extern void memleak_init(void);
+extern void memleak_alloc(const void *ptr, size_t size, int ref_count);
+extern void memleak_free(const void *ptr);
+extern void memleak_padding(const void *ptr, unsigned long offset, size_t size);
+extern void memleak_not_leak(const void *ptr);
+extern void memleak_ignore(const void *ptr);
+extern void memleak_scan_area(const void *ptr, unsigned long offset, size_t length);
+extern void memleak_insert_aliases(struct memleak_offset *ml_off_start,
+ struct memleak_offset *ml_off_end);
+
+static inline void memleak_erase(void **ptr)
+{
+ *ptr = NULL;
+}
+
+#define memleak_container(type, member) { \
+ DECLARE_MEMLEAK_OFFSET(container_of, type, member); \
+}
+
+extern void memleak_typeid_raw(const void *ptr, unsigned long type_id);
+#define memleak_typeid(ptr, type) \
+ memleak_typeid_raw(ptr, ml_typeid(type))
+
+#else
+
+#define DECLARE_MEMLEAK_OFFSET(name, type, member)
+
+static inline void memleak_init(void)
+{ }
+static inline void memleak_alloc(const void *ptr, size_t size, int ref_count)
+{ }
+static inline void memleak_free(const void *ptr)
+{ }
+static inline void memleak_padding(const void *ptr, unsigned long offset, size_t size)
+{ }
+static inline void memleak_not_leak(const void *ptr)
+{ }
+static inline void memleak_ignore(const void *ptr)
+{ }
+static inline void memleak_scan_area(const void *ptr, unsigned long offset, size_t length)
+{ }
+static inline void memleak_insert_aliases(struct memleak_offset *ml_off_start,
+ struct memleak_offset *ml_off_end)
+{ }
+static inline void memleak_erase(void **ptr)
+{ }
+
+#define memleak_container(type, member)
+
+static inline void memleak_typeid_raw(const void *ptr, unsigned long type_id)
+{ }
+#define memleak_typeid(ptr, type)
+
+#endif /* CONFIG_DEBUG_MEMLEAK */
+
+#endif /* __MEMLEAK_H */
diff --git a/init/main.c b/init/main.c
index 8651a72..6497f61 100644
--- a/init/main.c
+++ b/init/main.c
@@ -548,6 +548,8 @@ #endif
cpuset_init_early();
mem_init();
kmem_cache_init();
+ radix_tree_init();
+ memleak_init();
setup_per_cpu_pageset();
numa_policy_init();
if (late_time_init)
@@ -568,7 +570,6 @@ #endif
key_init();
security_init();
vfs_caches_init(num_physpages);
- radix_tree_init();
signals_init();
/* rootfs populating might need page-writeback */
page_writeback_init();
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 554ee68..1786cb5 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -105,6 +105,96 @@ config DEBUG_SLAB_LEAK
bool "Memory leak debugging"
depends on DEBUG_SLAB
+menuconfig DEBUG_MEMLEAK
+ bool "Kernel memory leak detector"
+ default n
+ depends on EXPERIMENTAL && DEBUG_SLAB
+ select DEBUG_FS
+ help
+ Say Y here if you want to enable the memory leak
+ detector. The memory allocation/freeing is traced in a way
+ similar to the Boehm's conservative garbage collector, the
+ difference being that the orphan objects are not freed but
+ only shown in /sys/kernel/debug/memleak. Enabling this
+ feature will introduce an overhead to memory
+ allocations. See Documentation/kmemleak.txt for more
+ details.
+
+ In order to access the memleak file, debugfs needs to be
+ mounted (usually at /sys/kernel/debug).
+
+config DEBUG_MEMLEAK_HASH_BITS
+ int "Pointer hash bits"
+ default 16
+ depends on DEBUG_MEMLEAK
+ help
+ This option sets the number of bits used for the pointer
+ hash table. Higher value gives better memory scanning
+ performance but also uses more RAM. The size of the
+ allocated hash table is (sizeof(void *) * 2^hash_bits).
+
+config DEBUG_MEMLEAK_TRACE_LENGTH
+ int "Stack trace length"
+ default 4
+ depends on DEBUG_MEMLEAK && FRAME_POINTER
+ help
+ This option sets the length of the stack trace for the
+ allocated objects tracked by kmemleak.
+
+config DEBUG_MEMLEAK_PREINIT_OBJECTS
+ int "Pre-init actions buffer size"
+ default 512
+ depends on DEBUG_MEMLEAK
+ help
+ This is the buffer for storing the memory allocation/freeing
+ calls before kmemleak is fully initialized. Each element in
+ the buffer takes 24 bytes on a 32 bit architecture. This
+ buffer will be freed once the system initialization is
+ completed.
+
+config DEBUG_MEMLEAK_SECONDARY_ALIASES
+ bool "Create secondary level pointer aliases"
+ default y
+ depends on DEBUG_MEMLEAK
+ help
+ This option creates aliases for container_of(container_of(member))
+ access to objects. Disabling this option reduces the chances of
+ false negatives but it can slightly increase the number of false
+ positives.
+
+config DEBUG_MEMLEAK_TASK_STACKS
+ bool "Scan task kernel stacks"
+ default y
+ depends on DEBUG_MEMLEAK
+ help
+ This option enables the scanning of the task kernel
+ stacks. This option can introduce false negatives because of
+ the randomness of stacks content.
+
+ If unsure, say Y.
+
+config DEBUG_MEMLEAK_ORPHAN_FREEING
+ bool "Notify when freeing orphan objects"
+ default n
+ depends on DEBUG_MEMLEAK
+ help
+ This option enables the notification when objects
+ considered leaks are freed. The stack dump and the object
+ information displayed allow an easier identification of
+ false positives. Use this mainly for debugging kmemleak.
+
+ If unsure, say N.
+
+config DEBUG_MEMLEAK_REPORTS_NR
+ int "Maximum number of reported leaks"
+ default 100
+ depends on DEBUG_MEMLEAK
+ help
+ This option sets the maximum number of leaks reported. If
+ this number is too big and there are leaks to be reported,
+ reading the /sys/kernel/debug/memleak file could lead to
+ some soft-locks.
+
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
diff --git a/mm/Makefile b/mm/Makefile
index 9dd824c..edccbc0 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -23,4 +23,4 @@ obj-$(CONFIG_SLAB) += slab.o
obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o
obj-$(CONFIG_FS_XIP) += filemap_xip.o
obj-$(CONFIG_MIGRATION) += migrate.o
-
+obj-$(CONFIG_DEBUG_MEMLEAK) += memleak.o
diff --git a/mm/memleak.c b/mm/memleak.c
new file mode 100644
index 0000000..0b5aa0c
--- /dev/null
+++ b/mm/memleak.c
@@ -0,0 +1,1518 @@
+/*
+ * mm/memleak.c
+ *
+ * Copyright (C) 2006 ARM Limited
+ * Written by Catalin Marinas <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ *
+ * Notes on locking
+ *
+ * Kmemleak needs to allocate/free memory for its own data structures:
+ * the memleak_object, the pointer hash and aliases radix trees. The
+ * memleak_free hook can be called from mm/slab.c with the list_lock
+ * held (i.e. when releasing off-slab management structures) and it
+ * will ackquire the memleak_lock. To avoid deadlocks caused by
+ * locking dependency, the list_lock must not be acquired while
+ * memleak_lock is held. This is ensured by not allocating/freeing
+ * memory while any of the kmemleak locks are held.
+ *
+ * The kmemleak hooks cannot be called concurrently on the same
+ * memleak_object (this is due to the way they were inserted in the
+ * kernel).
+ *
+ * The following locks are present in kmemleak:
+ *
+ * - alias_tree_lock - rwlock for accessing the radix tree holding the
+ * objects type information
+ *
+ * - memleak_lock - global kmemleak lock; protects object_list,
+ * last_object, pointer_hash and memleak_object structures
+ *
+ * Locking dependencies:
+ *
+ * - alias_tree_lock --> l3->list_lock
+ * - l3->list_lock --> memleak_lock
+ */
+
+/* #define DEBUG */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/radix-tree.h>
+#include <linux/gfp.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/kallsyms.h>
+#include <linux/mman.h>
+#include <linux/nodemask.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/cpumask.h>
+#include <linux/spinlock.h>
+#include <linux/rcupdate.h>
+#include <linux/hash.h>
+
+#include <asm/bitops.h>
+#include <asm/sections.h>
+#include <asm/percpu.h>
+#include <asm/processor.h>
+#include <asm/thread_info.h>
+#include <asm/atomic.h>
+
+#include <linux/memleak.h>
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+#define BUG_ON_LOCKING(cond) BUG_ON(cond)
+#else
+#define BUG_ON_LOCKING(cond)
+#endif
+
+#ifdef CONFIG_FRAME_POINTER
+#define MAX_TRACE CONFIG_DEBUG_MEMLEAK_TRACE_LENGTH
+#else
+#define MAX_TRACE 1
+#endif
+
+#define SCAN_BLOCK_SIZE 4096 /* maximum scan length with interrupts disabled */
+#define PREINIT_OBJECTS CONFIG_DEBUG_MEMLEAK_PREINIT_OBJECTS
+#define HASH_BITS CONFIG_DEBUG_MEMLEAK_HASH_BITS
+#define BYTES_PER_WORD sizeof(void *)
+
+extern struct memleak_offset __memleak_offsets_start[];
+extern struct memleak_offset __memleak_offsets_end[];
+
+struct memleak_alias {
+ struct hlist_node node;
+ unsigned long offset;
+};
+
+struct memleak_scan_area {
+ struct hlist_node node;
+ unsigned long offset;
+ size_t length;
+};
+
+struct memleak_object {
+ unsigned long flags;
+ struct list_head object_list;
+ struct list_head gray_list;
+ struct rcu_head rcu;
+ int use_count;
+ unsigned long pointer;
+ unsigned long offset; /* padding */
+ size_t size;
+ unsigned long type_id;
+ int ref_count; /* the minimum encounters of the value */
+ int count; /* the ecounters of the value */
+ struct hlist_head *alias_list;
+ struct hlist_head area_list; /* areas to be scanned (or empty for all) */
+ unsigned long trace[MAX_TRACE];
+};
+
+struct hash_node {
+ struct hlist_node node;
+ unsigned long val;
+ void *object;
+};
+
+enum memleak_action {
+ MEMLEAK_ALLOC,
+ MEMLEAK_FREE,
+ MEMLEAK_PADDING,
+ MEMLEAK_NOT_LEAK,
+ MEMLEAK_IGNORE,
+ MEMLEAK_SCAN_AREA,
+ MEMLEAK_TYPEID
+};
+
+struct memleak_preinit_object {
+ enum memleak_action type;
+ const void *pointer;
+ unsigned long offset;
+ size_t size;
+ unsigned long type_id;
+ int ref_count;
+};
+
+/* Tree storing the pointer aliases indexed by size */
+static RADIX_TREE(alias_tree, GFP_ATOMIC);
+static DEFINE_RWLOCK(alias_tree_lock);
+/* Hash storing all the possible objects, indexed by the pointer value */
+static struct hlist_head *pointer_hash;
+/* The list of all allocated objects */
+static LIST_HEAD(object_list);
+/* The list of the gray objects */
+static LIST_HEAD(gray_list);
+
+static struct kmem_cache *object_cache;
+/* The main lock for protecting the object lists and radix trees */
+static DEFINE_SPINLOCK(memleak_lock);
+static cpumask_t memleak_cpu_mask = CPU_MASK_NONE;
+static atomic_t memleak_initialized = ATOMIC_INIT(0);
+static int __initdata preinit_pos;
+static struct memleak_preinit_object __initdata preinit_objects[PREINIT_OBJECTS];
+/* last allocated object (optimization); protected by memleak_lock */
+static struct memleak_object *last_object;
+#ifdef CONFIG_DEBUG_FS
+static int reported_leaks;
+#endif
+
+/* object flags */
+#define OBJECT_ALLOCATED 0x1
+#define OBJECT_TYPE_GUESSED 0x2
+
+/* Hash functions */
+static void hash_init(void)
+{
+ int i;
+ int hash_size = sizeof(*pointer_hash) * (1 << HASH_BITS);
+ int hash_order = fls(hash_size) - 1;
+
+ if (hash_size & ((1 << hash_order) - 1))
+ hash_order += 1;
+
+ pointer_hash = (struct hlist_head *)
+ __get_free_pages(GFP_ATOMIC, hash_order - PAGE_SHIFT);
+ if (!pointer_hash)
+ panic("kmemleak: cannot allocate the pointer hash\n");
+
+ for (i = 0; i < (1 << HASH_BITS); i++)
+ INIT_HLIST_HEAD(&pointer_hash[i]);
+}
+
+static struct hash_node *__hash_lookup_node(unsigned long val)
+{
+ struct hlist_node *elem;
+ struct hash_node *hnode;
+ unsigned long index = hash_long(val, HASH_BITS);
+
+ hlist_for_each_entry(hnode, elem, &pointer_hash[index], node) {
+ if (hnode->val == val)
+ return hnode;
+ }
+ return NULL;
+}
+
+static int hash_insert(unsigned long val, void *object)
+{
+ unsigned long flags;
+ unsigned long index = hash_long(val, HASH_BITS);
+ struct hash_node *hnode = kmalloc(sizeof(*hnode), GFP_ATOMIC);
+
+ if (!hnode)
+ return -ENOMEM;
+ INIT_HLIST_NODE(&hnode->node);
+ hnode->val = val;
+ hnode->object = object;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+ hlist_add_head(&hnode->node, &pointer_hash[index]);
+ spin_unlock_irqrestore(&memleak_lock, flags);
+
+ return 0;
+}
+
+static void *hash_delete(unsigned long val)
+{
+ unsigned long flags;
+ void *object = NULL;
+ struct hash_node *hnode;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+ hnode = __hash_lookup_node(val);
+ if (hnode) {
+ object = hnode->object;
+ hlist_del(&hnode->node);
+ }
+ spin_unlock_irqrestore(&memleak_lock, flags);
+
+ kfree(hnode);
+ return object;
+}
+
+/* memleak_lock held by the calling function and interrupts disabled */
+static void *hash_lookup(unsigned long val)
+{
+ struct hash_node *hnode;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+ BUG_ON_LOCKING(!spin_is_locked(&memleak_lock));
+
+ hnode = __hash_lookup_node(val);
+ if (hnode)
+ return hnode->object;
+ return NULL;
+}
+
+/* helper macros to avoid recursive calls. After disabling the
+ * interrupts, the only calls to this function on the same CPU should
+ * be from kmemleak itself and we can either ignore them or
+ * panic. Calls from other CPU's should be protected by spinlocks */
+#define recursive_enter(cpu_id, flags) ({ \
+ local_irq_save(flags); \
+ cpu_id = get_cpu(); \
+ cpu_test_and_set(cpu_id, memleak_cpu_mask); \
+})
+
+#define recursive_clear(cpu_id) do { \
+ cpu_clear(cpu_id, memleak_cpu_mask); \
+} while (0)
+
+#define recursive_exit(flags) do { \
+ put_cpu_no_resched(); \
+ local_irq_restore(flags); \
+} while (0)
+
+/* Object colors, encoded with count and ref_count:
+ * - white - orphan object, i.e. not enough references to it (ref_count >= 1)
+ * - gray - referred at least once and therefore non-orphan (ref_count == 0)
+ * - black - ignore; it doesn't contain references (text section) (ref_count == -1) */
+static inline int color_white(const struct memleak_object *object)
+{
+ return object->count != -1 && object->count < object->ref_count;
+}
+
+static inline int color_gray(const struct memleak_object *object)
+{
+ return object->ref_count != -1 && object->count >= object->ref_count;
+}
+
+static inline int color_black(const struct memleak_object *object)
+{
+ return object->ref_count == -1;
+}
+
+#ifdef CONFIG_KALLSYMS
+static inline void dump_symbol_name(unsigned long addr)
+{
+ char namebuf[KSYM_NAME_LEN + 1] = "";
+ char *modname;
+ unsigned long symsize;
+ unsigned long offset = 0;
+
+ kallsyms_lookup(addr, &symsize, &offset, &modname, namebuf);
+ printk(KERN_NOTICE " %lx: <%s>\n", addr, namebuf);
+}
+#else
+static inline void dump_symbol_name(unsigned long addr)
+{
+ printk(KERN_NOTICE " %lx\n", addr);
+}
+#endif
+
+#ifdef DEBUG
+static inline void dump_object_internals(struct memleak_object *object)
+{
+ struct memleak_alias *alias;
+ struct hlist_node *elem;
+
+ printk(KERN_NOTICE " size = %d\n", object->size);
+ printk(KERN_NOTICE " ref_count = %d\n", object->ref_count);
+ printk(KERN_NOTICE " count = %d\n", object->count);
+ printk(KERN_NOTICE " aliases:\n");
+ if (object->alias_list) {
+ hlist_for_each_entry(alias, elem, object->alias_list, node)
+ printk(KERN_NOTICE " 0x%lx\n", alias->offset);
+ }
+}
+#else
+static inline void dump_object_internals(struct memleak_object *object)
+{ }
+#endif
+
+static void dump_object_info(struct memleak_object *object)
+{
+ int i;
+
+ printk(KERN_NOTICE "kmemleak: object 0x%08lx:\n", object->pointer);
+ dump_object_internals(object);
+ printk(KERN_NOTICE " trace:\n");
+ for (i = 0; i < MAX_TRACE; i++) {
+ unsigned long trace = object->trace[i];
+
+ if (!trace)
+ break;
+ dump_symbol_name(trace);
+ }
+}
+
+/* Insert an element into the aliases radix tree.
+ * Return 0 on success. */
+static int insert_alias(unsigned long type_id, unsigned long offset)
+{
+ int ret = 0;
+ struct hlist_head *alias_list;
+ struct hlist_node *elem;
+ struct memleak_alias *alias;
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (type_id == 0 || offset == 0 || offset >= ml_sizeof(type_id))
+ return -EINVAL;
+
+ if (recursive_enter(cpu_id, flags))
+ BUG();
+ write_lock(&alias_tree_lock);
+
+ offset &= ~(BYTES_PER_WORD - 1);
+
+ alias_list = radix_tree_lookup(&alias_tree, type_id);
+ if (!alias_list) {
+ /* no alias list for this type id. Allocate list_head
+ * and insert into the radix tree */
+ alias_list = kmalloc(sizeof(*alias_list), GFP_ATOMIC);
+ if (!alias_list)
+ panic("kmemleak: cannot allocate alias_list\n");
+ INIT_HLIST_HEAD(alias_list);
+
+ ret = radix_tree_insert(&alias_tree, type_id, alias_list);
+ if (ret)
+ panic("kmemleak: cannot insert into the aliases radix tree: %d\n", ret);
+ }
+
+ hlist_for_each_entry(alias, elem, alias_list, node) {
+ if (alias->offset == offset) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
+
+ alias = kmalloc(sizeof(*alias), GFP_ATOMIC);
+ if (!alias)
+ panic("kmemleak: cannot allocate initial memory\n");
+ INIT_HLIST_NODE(&alias->node);
+ alias->offset = offset;
+
+ hlist_add_head_rcu(&alias->node, alias_list);
+
+ out:
+ write_unlock(&alias_tree_lock);
+ recursive_clear(cpu_id);
+ recursive_exit(flags);
+
+ return ret;
+}
+
+/* Insert pointer aliases from the given array */
+void memleak_insert_aliases(struct memleak_offset *ml_off_start,
+ struct memleak_offset *ml_off_end)
+{
+ struct memleak_offset *ml_off;
+ int i = 0;
+#ifdef CONFIG_DEBUG_MEMLEAK_SECONDARY_ALIASES
+ unsigned long flags;
+#endif
+
+ pr_debug("%s(0x%p, 0x%p)\n", __FUNCTION__, ml_off_start, ml_off_end);
+
+ /* primary aliases - container_of(member) */
+ for (ml_off = ml_off_start; ml_off < ml_off_end; ml_off++)
+ if (!insert_alias(ml_off->type_id, ml_off->offset))
+ i++;
+ pr_debug("kmemleak: found %d primary alias(es)\n", i);
+
+#ifdef CONFIG_DEBUG_MEMLEAK_SECONDARY_ALIASES
+ /* secondary aliases - container_of(container_of(member)) */
+ for (ml_off = ml_off_start; ml_off < ml_off_end; ml_off++) {
+ struct hlist_head *alias_list;
+ struct memleak_alias *alias;
+ struct hlist_node *elem;
+
+ /* with imprecise type identification, if the member
+ * id is the same as the outer structure id, just
+ * ignore as any potential aliases are already in the
+ * tree */
+ if (ml_off->member_type_id == ml_off->type_id)
+ continue;
+
+ read_lock_irqsave(&alias_tree_lock, flags);
+ alias_list = radix_tree_lookup(&alias_tree, ml_off->member_type_id);
+ read_unlock_irqrestore(&alias_tree_lock, flags);
+ if (!alias_list)
+ continue;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(alias, elem, alias_list, node)
+ if (!insert_alias(ml_off->type_id, ml_off->offset + alias->offset))
+ i++;
+ rcu_read_unlock();
+ }
+ pr_debug("kmemleak: found %d alias(es)\n", i);
+#endif
+}
+EXPORT_SYMBOL_GPL(memleak_insert_aliases);
+
+/* called with interrupts disabled */
+static inline struct memleak_object *get_cached_object(unsigned long ptr)
+{
+ struct memleak_object *object;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ spin_lock(&memleak_lock);
+ if (!last_object || ptr != last_object->pointer)
+ last_object = hash_lookup(ptr);
+ object = last_object;
+ spin_unlock(&memleak_lock);
+
+ return object;
+}
+
+/* no need for atomic operations since memleak_lock is already held
+ * and interrupts disabled. Return 1 if successful or 0 otherwise */
+static inline int get_object(struct memleak_object *object)
+{
+ BUG_ON_LOCKING(!irqs_disabled());
+ BUG_ON_LOCKING(!spin_is_locked(&memleak_lock));
+
+ if (object->use_count != 0)
+ object->use_count++;
+ return object->use_count != 0;
+}
+
+static void free_object_rcu(struct rcu_head *rcu)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+ struct hlist_node *elem, *tmp;
+ struct memleak_scan_area *area;
+ struct memleak_object *object =
+ container_of(rcu, struct memleak_object, rcu);
+
+ if (recursive_enter(cpu_id, flags))
+ BUG();
+
+ /* once use_count is 0, there is no code accessing the object */
+ hlist_for_each_entry_safe(area, elem, tmp, &object->area_list, node) {
+ hlist_del(elem);
+ kfree(area);
+ }
+ kmem_cache_free(object_cache, object);
+
+ recursive_clear(cpu_id);
+ recursive_exit(flags);
+}
+
+/* called without memleak_lock held */
+static void put_object(struct memleak_object *object)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+
+ if (--object->use_count > 0)
+ goto out;
+
+ /* should only get here after delete_object was called */
+ BUG_ON(object->flags & OBJECT_ALLOCATED);
+
+ /* the last reference to this object */
+ list_del_rcu(&object->object_list);
+ call_rcu(&object->rcu, free_object_rcu);
+
+ out:
+ spin_unlock_irqrestore(&memleak_lock, flags);
+}
+
+/* called with interrupts disabled (no need to hold the memleak_lock
+ * as the the pointer aliases functions cannot be called concurrently
+ * on the same object) */
+static void delete_pointer_aliases(struct memleak_object *object)
+{
+ struct memleak_alias *alias;
+ struct hlist_node *elem;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ if (object->offset)
+ hash_delete(object->pointer + object->offset);
+
+ if (object->alias_list) {
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(alias, elem, object->alias_list, node)
+ hash_delete(object->pointer
+ + object->offset + alias->offset);
+ rcu_read_unlock();
+ object->alias_list = NULL;
+ }
+}
+
+/* called with interrupts disabled (see above for why memleak_lock
+ * doesn't need to be held) */
+static void create_pointer_aliases(struct memleak_object *object)
+{
+ struct memleak_alias *alias;
+ struct hlist_node *elem;
+ int err;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ if (object->offset) {
+ err = hash_insert(object->pointer + object->offset, object);
+ if (err) {
+ dump_stack();
+ panic("kmemleak: cannot insert offset into the pointer hash table: %d\n", err);
+ }
+ }
+
+ read_lock(&alias_tree_lock);
+ object->alias_list = radix_tree_lookup(&alias_tree, object->type_id);
+ read_unlock(&alias_tree_lock);
+
+ if (object->alias_list) {
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(alias, elem, object->alias_list, node) {
+ err = hash_insert(object->pointer + object->offset
+ + alias->offset, object);
+ if (err) {
+ dump_stack();
+ panic("kmemleak: cannot insert alias into the pointer hash table: %d\n", err);
+ }
+ }
+ rcu_read_unlock();
+ }
+}
+
+/* Insert a pointer and its aliases into the pointer hash table */
+static inline void create_object(unsigned long ptr, size_t size, int ref_count)
+{
+ struct memleak_object *object;
+ int err;
+#ifdef CONFIG_FRAME_POINTER
+ int i;
+ void *frame;
+#endif
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ object = kmem_cache_alloc(object_cache, SLAB_ATOMIC);
+ if (!object)
+ panic("kmemleak: cannot allocate a memleak_object structure\n");
+
+ INIT_LIST_HEAD(&object->object_list);
+ INIT_LIST_HEAD(&object->gray_list);
+ INIT_HLIST_HEAD(&object->area_list);
+ object->flags = OBJECT_TYPE_GUESSED;
+ object->use_count = 1;
+ object->pointer = ptr;
+ object->offset = 0;
+ object->size = size;
+ object->type_id = ml_guess_typeid(size); /* type id approximation */
+ object->ref_count = ref_count;
+ object->count = -1;
+ object->alias_list = NULL;
+
+#ifdef CONFIG_FRAME_POINTER
+ frame = __builtin_frame_address(0);
+ for (i = 0; i < MAX_TRACE; i++) {
+ void *stack = task_stack_page(current);
+
+ if (frame < stack || frame > stack + THREAD_SIZE - BYTES_PER_WORD) {
+ object->trace[i] = 0;
+ continue;
+ }
+
+ object->trace[i] = arch_call_address(frame);
+ frame = arch_prev_frame(frame);
+ /* we don't need the return to do_exit() */
+ if (kstack_end(frame))
+ object->trace[i] = 0;
+ }
+#else
+ object->trace[0] = (unsigned long)__builtin_return_address(0);
+#endif
+
+ spin_lock(&memleak_lock);
+ /* object->use_count already set to 1 */
+ list_add_tail_rcu(&object->object_list, &object_list);
+ spin_unlock(&memleak_lock);
+
+ err = hash_insert(ptr, object);
+ if (err) {
+ dump_stack();
+ if (err == -EEXIST) {
+ printk(KERN_NOTICE "Existing pointer:\n");
+ spin_lock(&memleak_lock);
+ object = hash_lookup(ptr);
+ dump_object_info(object);
+ spin_unlock(&memleak_lock);
+ }
+ panic("kmemleak: cannot insert 0x%lx into the pointer hash table: %d\n",
+ ptr, err);
+ }
+
+ create_pointer_aliases(object);
+
+ /* everything completed fine, just mark the object as allocated */
+ spin_lock(&memleak_lock);
+ object->flags |= OBJECT_ALLOCATED;
+ last_object = object;
+ spin_unlock(&memleak_lock);
+}
+
+/* Remove a pointer and its aliases from the pointer hash table */
+static inline void delete_object(unsigned long ptr)
+{
+ struct memleak_object *object;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ object = hash_delete(ptr);
+ if (!object) {
+ dump_stack();
+ printk(KERN_WARNING "kmemleak: freeing unknown object at 0x%08lx\n", ptr);
+ return;
+ }
+
+ spin_lock(&memleak_lock);
+
+ if (object->pointer != ptr) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: freeing object by alias 0x%08lx\n", ptr);
+ }
+ BUG_ON(!(object->flags & OBJECT_ALLOCATED));
+
+ object->flags &= ~OBJECT_ALLOCATED;
+
+ /* deleting the cached object */
+ if (last_object && ptr == last_object->pointer)
+ last_object = NULL;
+
+#ifdef CONFIG_DEBUG_MEMLEAK_ORPHAN_FREEING
+ if (color_white(object)) {
+ dump_stack();
+ dump_object_info(object);
+ printk(KERN_WARNING "kmemleak: freeing orphan object 0x%08lx\n", ptr);
+ }
+#endif
+
+ spin_unlock(&memleak_lock);
+
+ delete_pointer_aliases(object);
+ object->pointer = 0;
+ put_object(object);
+}
+
+/* Re-create the pointer aliases according to the new size/offset
+ * information */
+static inline void unpad_object(unsigned long ptr, unsigned long offset,
+ size_t size)
+{
+ struct memleak_object *object;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ object = get_cached_object(ptr);
+ if (!object) {
+ dump_stack();
+ panic("kmemleak: resizing unknown object at 0x%08lx\n", ptr);
+ }
+ if (object->pointer != ptr) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: resizing object by alias 0x%08lx\n", ptr);
+ }
+ if (offset + size > object->size) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: new boundaries exceed object 0x%08lx\n", ptr);
+ }
+
+ /* nothing changed */
+ if (offset == object->offset && size == object->size)
+ return;
+
+ /* re-create the pointer aliases */
+ delete_pointer_aliases(object);
+
+ spin_lock(&memleak_lock);
+ object->offset = offset;
+ object->size = size;
+ if (object->flags & OBJECT_TYPE_GUESSED)
+ object->type_id = ml_guess_typeid(size);
+ spin_unlock(&memleak_lock);
+
+ create_pointer_aliases(object);
+}
+
+/* Make a object permanently gray (false positive) */
+static inline void make_gray_object(unsigned long ptr)
+{
+ struct memleak_object *object;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ object = get_cached_object(ptr);
+ if (!object) {
+ dump_stack();
+ panic("kmemleak: graying unknown object at 0x%08lx\n", ptr);
+ }
+ if (object->pointer != ptr) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: graying object by alias 0x%08lx\n", ptr);
+ }
+
+ spin_lock(&memleak_lock);
+ object->ref_count = 0;
+ spin_unlock(&memleak_lock);
+}
+
+/* Mark the object as black */
+static inline void make_black_object(unsigned long ptr)
+{
+ struct memleak_object *object;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ object = get_cached_object(ptr);
+ if (!object) {
+ dump_stack();
+ panic("kmemleak: blacking unknown object at 0x%08lx\n", ptr);
+ }
+ if (object->pointer != ptr) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: blacking object by alias 0x%08lx\n", ptr);
+ }
+
+ spin_lock(&memleak_lock);
+ object->ref_count = -1;
+ spin_unlock(&memleak_lock);
+}
+
+/* Add a scanning area to the object */
+static inline void add_scan_area(unsigned long ptr, unsigned long offset, size_t length)
+{
+ struct memleak_object *object;
+ struct memleak_scan_area *area;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ area = kmalloc(sizeof(*area), GFP_ATOMIC);
+ if (!area)
+ panic("kmemleak: cannot allocate a scan area\n");
+
+ INIT_HLIST_NODE(&area->node);
+ area->offset = offset;
+ area->length = length;
+
+ object = get_cached_object(ptr);
+ if (!object) {
+ dump_stack();
+ panic("kmemleak: adding scan area to unknown object at 0x%08lx\n", ptr);
+ }
+ if (object->pointer != ptr) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: adding scan area to object by alias 0x%08lx\n", ptr);
+ }
+ if (offset + length > object->size) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: scan area larger than object 0x%08lx\n", ptr);
+ }
+
+ spin_lock(&memleak_lock);
+ hlist_add_head(&area->node, &object->area_list);
+ spin_unlock(&memleak_lock);
+}
+
+/* Re-create the pointer aliases according to the new type id */
+static inline void change_type_id(unsigned long ptr, unsigned long type_id)
+{
+ struct memleak_object *object;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+
+ object = get_cached_object(ptr);
+ if (!object) {
+ dump_stack();
+ panic("kmemleak: changing type of unknown object at 0x%08lx\n", ptr);
+ }
+ if (object->pointer != ptr) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: changing type of object by alias 0x%08lx\n", ptr);
+ }
+ if (ml_sizeof(type_id) > object->size) {
+ dump_stack();
+ dump_object_info(object);
+ panic("kmemleak: new type larger than object 0x%08lx\n", ptr);
+ }
+
+ spin_lock(&memleak_lock);
+ object->type_id = type_id;
+ object->flags &= ~OBJECT_TYPE_GUESSED;
+ spin_unlock(&memleak_lock);
+
+ if (type_id == object->type_id)
+ return;
+
+ delete_pointer_aliases(object);
+ create_pointer_aliases(object);
+}
+
+/* Allocation function hook */
+void memleak_alloc(const void *ptr, size_t size, int ref_count)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (!ptr)
+ return;
+
+ if (recursive_enter(cpu_id, flags))
+ goto out;
+
+ pr_debug("%s(0x%p, %d, %d)\n", __FUNCTION__, ptr, size, ref_count);
+
+ if (!atomic_read(&memleak_initialized)) {
+ /* no need for SMP locking since this object is
+ * executed before the other CPUs are started */
+ struct memleak_preinit_object *object;
+
+ BUG_ON(cpu_id != 0);
+
+ if (preinit_pos < PREINIT_OBJECTS) {
+ object = &preinit_objects[preinit_pos];
+
+ object->type = MEMLEAK_ALLOC;
+ object->pointer = ptr;
+ object->size = size;
+ object->ref_count = ref_count;
+ }
+ preinit_pos++;
+
+ goto clear;
+ }
+
+ create_object((unsigned long)ptr, size, ref_count);
+
+ clear:
+ recursive_clear(cpu_id);
+ out:
+ recursive_exit(flags);
+}
+EXPORT_SYMBOL_GPL(memleak_alloc);
+
+/* Freeing function hook */
+void memleak_free(const void *ptr)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (!ptr)
+ return;
+
+ if (recursive_enter(cpu_id, flags))
+ goto out;
+
+ pr_debug("%s(0x%p)\n", __FUNCTION__, ptr);
+
+ if (!atomic_read(&memleak_initialized)) {
+ struct memleak_preinit_object *object;
+
+ BUG_ON(cpu_id != 0);
+
+ if (preinit_pos < PREINIT_OBJECTS) {
+ object = &preinit_objects[preinit_pos];
+
+ object->type = MEMLEAK_FREE;
+ object->pointer = ptr;
+ }
+ preinit_pos++;
+
+ goto clear;
+ }
+
+ delete_object((unsigned long)ptr);
+
+ clear:
+ recursive_clear(cpu_id);
+ out:
+ recursive_exit(flags);
+}
+EXPORT_SYMBOL_GPL(memleak_free);
+
+/* Change the size and location information of an allocated memory
+ * object (this is needed for allocations padding the object) */
+void memleak_padding(const void *ptr, unsigned long offset, size_t size)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (!ptr)
+ return;
+
+ if (recursive_enter(cpu_id, flags))
+ goto out;
+
+ pr_debug("%s(0x%p, %d)\n", __FUNCTION__, ptr, size);
+
+ if (!atomic_read(&memleak_initialized)) {
+ struct memleak_preinit_object *object;
+
+ BUG_ON(cpu_id != 0);
+
+ if (preinit_pos < PREINIT_OBJECTS) {
+ object = &preinit_objects[preinit_pos];
+
+ object->type = MEMLEAK_PADDING;
+ object->pointer = ptr;
+ object->offset = offset;
+ object->size = size;
+ }
+ preinit_pos++;
+
+ goto clear;
+ }
+
+ unpad_object((unsigned long)ptr, offset, size);
+
+ clear:
+ recursive_clear(cpu_id);
+ out:
+ recursive_exit(flags);
+}
+EXPORT_SYMBOL(memleak_padding);
+
+/* Mark a object as a false positive */
+void memleak_not_leak(const void *ptr)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (!ptr)
+ return;
+
+ if (recursive_enter(cpu_id, flags))
+ goto out;
+
+ pr_debug("%s(0x%p)\n", __FUNCTION__, ptr);
+
+ if (!atomic_read(&memleak_initialized)) {
+ struct memleak_preinit_object *object;
+
+ BUG_ON(cpu_id != 0);
+
+ if (preinit_pos < PREINIT_OBJECTS) {
+ object = &preinit_objects[preinit_pos];
+
+ object->type = MEMLEAK_NOT_LEAK;
+ object->pointer = ptr;
+ }
+ preinit_pos++;
+
+ goto clear;
+ }
+
+ make_gray_object((unsigned long)ptr);
+
+ clear:
+ recursive_clear(cpu_id);
+ out:
+ recursive_exit(flags);
+}
+EXPORT_SYMBOL(memleak_not_leak);
+
+/* Ignore this memory object */
+void memleak_ignore(const void *ptr)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (!ptr)
+ return;
+
+ if (recursive_enter(cpu_id, flags))
+ goto out;
+
+ pr_debug("%s(0x%p)\n", __FUNCTION__, ptr);
+
+ if (!atomic_read(&memleak_initialized)) {
+ struct memleak_preinit_object *object;
+
+ BUG_ON(cpu_id != 0);
+
+ if (preinit_pos < PREINIT_OBJECTS) {
+ object = &preinit_objects[preinit_pos];
+
+ object->type = MEMLEAK_IGNORE;
+ object->pointer = ptr;
+ }
+ preinit_pos++;
+
+ goto clear;
+ }
+
+ make_black_object((unsigned long)ptr);
+
+ clear:
+ recursive_clear(cpu_id);
+ out:
+ recursive_exit(flags);
+}
+EXPORT_SYMBOL(memleak_ignore);
+
+/* Add a scanning area to a object */
+void memleak_scan_area(const void *ptr, unsigned long offset, size_t length)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (!ptr)
+ return;
+
+ if (recursive_enter(cpu_id, flags))
+ goto out;
+
+ pr_debug("%s(0x%p)\n", __FUNCTION__, ptr);
+
+ if (!atomic_read(&memleak_initialized)) {
+ struct memleak_preinit_object *object;
+
+ BUG_ON(cpu_id != 0);
+
+ if (preinit_pos < PREINIT_OBJECTS) {
+ object = &preinit_objects[preinit_pos];
+
+ object->type = MEMLEAK_SCAN_AREA;
+ object->pointer = ptr;
+ object->offset = offset;
+ object->size = length;
+ }
+ preinit_pos++;
+
+ goto clear;
+ }
+
+ add_scan_area((unsigned long)ptr, offset, length);
+
+ clear:
+ recursive_clear(cpu_id);
+ out:
+ recursive_exit(flags);
+}
+EXPORT_SYMBOL(memleak_scan_area);
+
+/* Change the type id of an allocated memory object */
+void memleak_typeid_raw(const void *ptr, unsigned long type_id)
+{
+ unsigned long flags;
+ unsigned int cpu_id;
+
+ if (!ptr)
+ return;
+ if (!type_id)
+ return;
+
+ if (recursive_enter(cpu_id, flags))
+ goto out;
+
+ pr_debug("%s(0x%p, %ld)\n", __FUNCTION__, ptr, type_id);
+
+ if (!atomic_read(&memleak_initialized)) {
+ struct memleak_preinit_object *object;
+
+ BUG_ON(cpu_id != 0);
+
+ if (preinit_pos < PREINIT_OBJECTS) {
+ object = &preinit_objects[preinit_pos];
+
+ object->type = MEMLEAK_TYPEID;
+ object->pointer = ptr;
+ object->type_id = type_id;
+ }
+ preinit_pos++;
+
+ goto clear;
+ }
+
+ change_type_id((unsigned long)ptr, type_id);
+
+ clear:
+ recursive_clear(cpu_id);
+ out:
+ recursive_exit(flags);
+}
+EXPORT_SYMBOL(memleak_typeid_raw);
+
+/* Scan a block of memory (exclusive range) for pointers and move
+ * those found to the gray list. This function is called with
+ * memleak_lock held and interrupts disabled */
+static void __scan_block(void *_start, void *_end)
+{
+ unsigned long *ptr;
+ unsigned long *start = (unsigned long *)ALIGN((unsigned long)_start,
+ BYTES_PER_WORD);
+ unsigned long *end = _end;
+
+ BUG_ON_LOCKING(!irqs_disabled());
+ BUG_ON_LOCKING(!spin_is_locked(&memleak_lock));
+
+ for (ptr = start; ptr < end; ptr++) {
+ struct memleak_object *object =
+ hash_lookup((*ptr) & ~(BYTES_PER_WORD - 1));
+ if (!object)
+ continue;
+ if (!color_white(object))
+ continue;
+
+ object->count++;
+ /* this can also happen during the gray_list traversal */
+ if (color_gray(object)) {
+ /* found in the hash, get_object() returns 1 */
+ get_object(object);
+ list_add_tail(&object->gray_list, &gray_list);
+ }
+ }
+}
+
+static void scan_block(void *start, void *end)
+{
+ unsigned long flags;
+ void *s, *e;
+
+ s = start;
+ while (s < end) {
+ e = s + SCAN_BLOCK_SIZE;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+ __scan_block(s, e < end ? e : end);
+ spin_unlock_irqrestore(&memleak_lock, flags);
+
+ s = e;
+ }
+}
+
+/* Scan a memory block represented by a memleak_object */
+static inline void scan_object(struct memleak_object *object)
+{
+ struct memleak_scan_area *area;
+ struct hlist_node *elem;
+ unsigned long flags;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+
+ /* freed object */
+ if (!(object->flags & OBJECT_ALLOCATED))
+ goto out;
+
+ if (hlist_empty(&object->area_list))
+ __scan_block((void *)(object->pointer + object->offset),
+ (void *)(object->pointer + object->offset
+ + object->size));
+ else
+ hlist_for_each_entry(area, elem, &object->area_list, node)
+ __scan_block((void *)(object->pointer + area->offset),
+ (void *)(object->pointer + area->offset
+ + area->length));
+
+ out:
+ spin_unlock_irqrestore(&memleak_lock, flags);
+}
+
+/* Scan the memory and print the orphan objects */
+static void memleak_scan(void)
+{
+ unsigned long flags;
+ struct memleak_object *object, *tmp;
+#ifdef CONFIG_DEBUG_MEMLEAK_TASK_STACKS
+ struct task_struct *task;
+#endif
+ int i;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ spin_lock_irqsave(&memleak_lock, flags);
+
+ /* there should be a maximum of 1 reference to any
+ * object at this point */
+ BUG_ON(object->use_count > 1);
+
+ /* reset the reference count (whiten the object) */
+ object->count = 0;
+ if (color_gray(object) && get_object(object))
+ list_add_tail(&object->gray_list, &gray_list);
+
+ spin_unlock_irqrestore(&memleak_lock, flags);
+ }
+ rcu_read_unlock();
+
+ /* data/bss scanning */
+ scan_block(_sdata, _edata);
+ scan_block(__bss_start, __bss_stop);
+
+#ifdef CONFIG_SMP
+ /* per-cpu scanning */
+ for (i = 0; i < NR_CPUS; i++)
+ scan_block(__per_cpu_offset[i] + __per_cpu_start,
+ __per_cpu_offset[i] + __per_cpu_end);
+#endif
+
+ /* mem_map scanning */
+ for_each_online_node(i) {
+ struct page *page, *end;
+
+ page = NODE_MEM_MAP(i);
+ end = page + NODE_DATA(i)->node_spanned_pages;
+
+ scan_block(page, end);
+ }
+
+#ifdef CONFIG_DEBUG_MEMLEAK_TASK_STACKS
+ read_lock(&tasklist_lock);
+ for_each_process(task)
+ scan_block(task_stack_page(task),
+ task_stack_page(task) + THREAD_SIZE);
+ read_unlock(&tasklist_lock);
+#endif
+
+ /* scan the objects already referenced. More objects will be
+ * referenced and, if there are no memory leaks, all the
+ * objects will be scanned. The list traversal is safe for
+ * both tail additions and removals from inside the loop. The
+ * memleak objects cannot be freed from outside the loop
+ * because their use_count was increased */
+ object = list_entry(gray_list.next, typeof(*object), gray_list);
+ while (&object->gray_list != &gray_list) {
+ /* may add new objects to the list */
+ scan_object(object);
+
+ tmp = list_entry(object->gray_list.next, typeof(*object),
+ gray_list);
+
+ /* remove the object from the list and release it */
+ list_del(&object->gray_list);
+ put_object(object);
+
+ object = tmp;
+ }
+ BUG_ON(!list_empty(&gray_list));
+}
+
+#ifdef CONFIG_DEBUG_FS
+static void *memleak_seq_start(struct seq_file *seq, loff_t *pos)
+{
+ struct memleak_object *object;
+ loff_t n = *pos;
+ unsigned long flags;
+
+ if (!n) {
+ memleak_scan();
+ reported_leaks = 0;
+ }
+ if (reported_leaks >= CONFIG_DEBUG_MEMLEAK_REPORTS_NR)
+ return NULL;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(object, &object_list, object_list) {
+ if (n-- > 0)
+ continue;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+ if (get_object(object)) {
+ spin_unlock_irqrestore(&memleak_lock, flags);
+ goto out;
+ }
+ spin_unlock_irqrestore(&memleak_lock, flags);
+ }
+ object = NULL;
+ out:
+ rcu_read_unlock();
+ return object;
+}
+
+static void *memleak_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct list_head *n;
+ struct memleak_object *next = NULL;
+ unsigned long flags;
+
+ ++(*pos);
+ if (reported_leaks >= CONFIG_DEBUG_MEMLEAK_REPORTS_NR)
+ return NULL;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+
+ n = ((struct memleak_object *)v)->object_list.next;
+ if (n != &object_list) {
+ next = list_entry(n, struct memleak_object, object_list);
+ /* still in the object_list, get_object() returns 1 */
+ get_object(next);
+ }
+
+ spin_unlock_irqrestore(&memleak_lock, flags);
+
+ put_object(v);
+ return next;
+}
+
+static void memleak_seq_stop(struct seq_file *seq, void *v)
+{
+ if (v)
+ put_object(v);
+}
+
+static int memleak_seq_show(struct seq_file *seq, void *v)
+{
+ const struct memleak_object *object = v;
+ unsigned long flags;
+#ifdef CONFIG_KALLSYMS
+ char namebuf[KSYM_NAME_LEN + 1] = "";
+ char *modname;
+ unsigned long symsize;
+ unsigned long offset = 0;
+#endif
+ int i;
+
+ spin_lock_irqsave(&memleak_lock, flags);
+
+ if (!color_white(object))
+ goto out;
+ /* freed in the meantime (false positive) or just allocated */
+ if (!(object->flags & OBJECT_ALLOCATED))
+ goto out;
+
+ reported_leaks++;
+ seq_printf(seq, "unreferenced object 0x%08lx (size %d):\n",
+ object->pointer, object->size);
+
+ for (i = 0; i < MAX_TRACE; i++) {
+ unsigned long trace = object->trace[i];
+ if (!trace)
+ break;
+
+#ifdef CONFIG_KALLSYMS
+ kallsyms_lookup(trace, &symsize, &offset, &modname, namebuf);
+ seq_printf(seq, " %lx: <%s>\n", trace, namebuf);
+#else
+ seq_printf(seq, " %lx\n", trace);
+#endif
+ }
+
+ out:
+ spin_unlock_irqrestore(&memleak_lock, flags);
+ return 0;
+}
+
+static struct seq_operations memleak_seq_ops = {
+ .start = memleak_seq_start,
+ .next = memleak_seq_next,
+ .stop = memleak_seq_stop,
+ .show = memleak_seq_show,
+};
+
+static int memleak_seq_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &memleak_seq_ops);
+}
+
+static struct file_operations memleak_fops = {
+ .owner = THIS_MODULE,
+ .open = memleak_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+#endif /* CONFIG_DEBUG_FS */
+
+/* KMemLeak initialization. Set up the radix tree for the pointer aliases */
+void __init memleak_init(void)
+{
+ int i;
+ unsigned long flags;
+
+ hash_init();
+
+ object_cache = kmem_cache_create("memleak_object_cache", sizeof(struct memleak_object),
+ 0, SLAB_PANIC, NULL, NULL);
+ if (!object_cache)
+ panic("kmemleak: cannot create the object cache\n");
+
+ memleak_insert_aliases(__memleak_offsets_start, __memleak_offsets_end);
+
+ /* no need to hold the spinlock as SMP is not initialized
+ * yet. Holding it here would lead to a deadlock */
+ local_irq_save(flags);
+
+ atomic_set(&memleak_initialized, 1);
+
+ if (preinit_pos >= PREINIT_OBJECTS)
+ panic("kmemleak: preinit objects buffer overflow: %d\n",
+ preinit_pos);
+
+ /* execute the buffered memleak actions */
+ pr_debug("kmemleak: %d preinit actions\n", preinit_pos);
+ for (i = 0; i < preinit_pos; i++) {
+ struct memleak_preinit_object *object = &preinit_objects[i];
+
+ switch (object->type) {
+ case MEMLEAK_ALLOC:
+ memleak_alloc(object->pointer, object->size,
+ object->ref_count);
+ break;
+ case MEMLEAK_FREE:
+ memleak_free(object->pointer);
+ break;
+ case MEMLEAK_PADDING:
+ memleak_padding(object->pointer, object->offset,
+ object->size);
+ break;
+ case MEMLEAK_NOT_LEAK:
+ memleak_not_leak(object->pointer);
+ break;
+ case MEMLEAK_IGNORE:
+ memleak_ignore(object->pointer);
+ break;
+ case MEMLEAK_SCAN_AREA:
+ memleak_scan_area(object->pointer,
+ object->offset, object->size);
+ break;
+ case MEMLEAK_TYPEID:
+ memleak_typeid_raw(object->pointer, object->type_id);
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ local_irq_restore(flags);
+
+ printk(KERN_INFO "Kernel memory leak detector initialized\n");
+}
+
+/* Late initialization function */
+int __init memleak_late_init(void)
+{
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *dentry;
+
+ dentry = debugfs_create_file("memleak", S_IRUGO, NULL, NULL,
+ &memleak_fops);
+ if (!dentry)
+ return -ENOMEM;
+#endif
+ pr_debug("kmemleak: late initialization completed\n");
+
+ return 0;
+}
+late_initcall(memleak_late_init);
From: Catalin Marinas <[email protected]>
This patch modifies the vmlinux.lds.S script and adds the backtrace support
for i386 to be used with kmemleak.
Signed-off-by: Catalin Marinas <[email protected]>
---
arch/i386/kernel/vmlinux.lds.S | 4 ++++
include/asm-i386/processor.h | 12 ++++++++++++
include/asm-i386/thread_info.h | 10 +++++++++-
3 files changed, 25 insertions(+), 1 deletions(-)
diff --git a/arch/i386/kernel/vmlinux.lds.S b/arch/i386/kernel/vmlinux.lds.S
index 2d4f138..34fccf1 100644
--- a/arch/i386/kernel/vmlinux.lds.S
+++ b/arch/i386/kernel/vmlinux.lds.S
@@ -45,6 +45,7 @@ SECTIONS
__tracedata_end = .;
/* writeable */
+ _sdata = .; /* Start of data section */
.data : AT(ADDR(.data) - LOAD_OFFSET) { /* Data */
*(.data)
CONSTRUCTORS
@@ -156,6 +157,9 @@ #endif
__per_cpu_start = .;
.data.percpu : AT(ADDR(.data.percpu) - LOAD_OFFSET) { *(.data.percpu) }
__per_cpu_end = .;
+ __memleak_offsets_start = .;
+ .init.memleak_offsets : AT(ADDR(.init.memleak_offsets) - LOAD_OFFSET) { *(.init.memleak_offsets) }
+ __memleak_offsets_end = .;
. = ALIGN(4096);
__init_end = .;
/* freed after init ends here */
diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index b32346d..29626e3 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -731,4 +731,16 @@ extern unsigned long boot_option_idle_ov
extern void enable_sep_cpu(void);
extern int sysenter_setup(void);
+#ifdef CONFIG_FRAME_POINTER
+static inline unsigned long arch_call_address(void *frame)
+{
+ return *(unsigned long *)(frame + 4);
+}
+
+static inline void *arch_prev_frame(void *frame)
+{
+ return *(void **)frame;
+}
+#endif
+
#endif /* __ASM_I386_PROCESSOR_H */
diff --git a/include/asm-i386/thread_info.h b/include/asm-i386/thread_info.h
index 54d6d7a..054553f 100644
--- a/include/asm-i386/thread_info.h
+++ b/include/asm-i386/thread_info.h
@@ -100,12 +100,20 @@ #define alloc_thread_info(tsk) \
struct thread_info *ret; \
\
ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
+ memleak_ignore(ret); \
if (ret) \
memset(ret, 0, THREAD_SIZE); \
ret; \
})
#else
-#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
+#define alloc_thread_info(tsk) \
+ ({ \
+ struct thread_info *ret; \
+ \
+ ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
+ memleak_ignore(ret); \
+ ret; \
+ })
#endif
#define free_thread_info(info) kfree(info)
From: Catalin Marinas <[email protected]>
This patch handles the kmemleak operations needed for modules loading so
that memory allocations from inside a module are properly tracked.
Signed-off-by: Catalin Marinas <[email protected]>
---
kernel/module.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 files changed, 41 insertions(+), 0 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index 2a19cd4..a7f8c6d 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1481,6 +1481,11 @@ static struct module *load_module(void _
unsigned int unusedcrcindex;
unsigned int unusedgplindex;
unsigned int unusedgplcrcindex;
+#ifdef CONFIG_DEBUG_MEMLEAK
+ unsigned int dataindex;
+ unsigned int bssindex;
+ unsigned int mloffindex;
+#endif
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
@@ -1577,6 +1582,11 @@ #endif
#ifdef ARCH_UNWIND_SECTION_NAME
unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
#endif
+#ifdef CONFIG_DEBUG_MEMLEAK
+ dataindex = find_sec(hdr, sechdrs, secstrings, ".data");
+ bssindex = find_sec(hdr, sechdrs, secstrings, ".bss");
+ mloffindex = find_sec(hdr, sechdrs, secstrings, ".init.memleak_offsets");
+#endif
/* Don't keep modinfo section */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
@@ -1646,6 +1656,10 @@ #endif
/* Do the allocs. */
ptr = module_alloc(mod->core_size);
+ /* the pointer to this block is stored in the module structure
+ * which is inside the block. Just mark it as not being a
+ * leak */
+ memleak_not_leak(ptr);
if (!ptr) {
err = -ENOMEM;
goto free_percpu;
@@ -1654,6 +1668,11 @@ #endif
mod->module_core = ptr;
ptr = module_alloc(mod->init_size);
+ /* the pointer to this block is stored in the module structure
+ * which is inside the block. This block doesn't need to be
+ * scanned as it contains data and code that will be freed
+ * after the module is initialized */
+ memleak_ignore(ptr);
if (!ptr && mod->init_size) {
err = -ENOMEM;
goto free_core;
@@ -1685,6 +1704,28 @@ #endif
/* Module has been moved. */
mod = (void *)sechdrs[modindex].sh_addr;
+#ifdef CONFIG_DEBUG_MEMLEAK
+ if (mloffindex)
+ memleak_insert_aliases((void *)sechdrs[mloffindex].sh_addr,
+ (void *)sechdrs[mloffindex].sh_addr
+ + sechdrs[mloffindex].sh_size);
+
+ /* only scan the sections containing data */
+ memleak_scan_area(mod->module_core,
+ (unsigned long)mod - (unsigned long)mod->module_core,
+ sizeof(struct module));
+ if (dataindex)
+ memleak_scan_area(mod->module_core,
+ sechdrs[dataindex].sh_addr
+ - (unsigned long)mod->module_core,
+ sechdrs[dataindex].sh_size);
+ if (bssindex)
+ memleak_scan_area(mod->module_core,
+ sechdrs[bssindex].sh_addr
+ - (unsigned long)mod->module_core,
+ sechdrs[bssindex].sh_size);
+#endif
+
/* Now we've moved module, initialize linked lists, etc. */
module_unload_init(mod);
From: Catalin Marinas <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>
---
Documentation/kmemleak.txt | 157 ++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 157 insertions(+), 0 deletions(-)
diff --git a/Documentation/kmemleak.txt b/Documentation/kmemleak.txt
new file mode 100644
index 0000000..e952e80
--- /dev/null
+++ b/Documentation/kmemleak.txt
@@ -0,0 +1,157 @@
+Kernel Memory Leak Detector
+===========================
+
+
+Introduction
+------------
+
+Kmemleak provides a way of detecting possible kernel memory leaks in a
+way similar to a tracing garbage collector
+(http://en.wikipedia.org/wiki/Garbage_collection_%28computer_science%29#Tracing_garbage_collectors),
+with the difference that the orphan pointers are not freed but only
+reported via /sys/kernel/debug/memleak. A similar method is used by
+the Valgrind tool (memcheck --leak-check) to detect the memory leaks
+in user-space applications.
+
+
+Usage
+-----
+
+CONFIG_DEBUG_MEMLEAK has to be enabled. For additional config options,
+look in:
+
+ -> Kernel hacking
+ -> Kernel debugging
+ -> Debug slab memory allocations
+ -> Kernel memory leak detector
+
+To display the possible memory leaks:
+
+ # mount -t debugfs nodev /sys/kernel/debug/
+ # cat /sys/kernel/debug/memleak
+
+In order to reduce the run-time overhead, memory scanning is only
+performed when reading the /sys/kernel/debug/memleak file.
+
+
+Basic Algorithm
+---------------
+
+The memory allocations via kmalloc, vmalloc, kmem_cache_alloc and
+friends are tracked and the pointers, together with additional
+information like size and stack trace, are stored in a hash table. The
+corresponding freeing function calls are tracked and the pointers
+removed from the hash table.
+
+An allocated block of memory is considered orphan if a pointer to its
+start address or to an alias (pointer aliases are explained later)
+cannot be found by scanning the memory (including saved
+registers). This means that there might be no way for the kernel to
+pass the address of the allocated block to a freeing function and
+therefore the block is considered a leak.
+
+The scanning algorithm steps:
+
+ 1. mark all pointers as white (remaining white pointers will later
+ be considered orphan)
+ 2. scan the memory starting with the data section and stacks,
+ checking the values against the addresses stored in the hash
+ table. If a white pointer is found, it is added to the grey list
+ 3. scan the grey pointers for matching addresses (some white
+ pointers can become grey and added at the end of the grey list)
+ until the grey set is finished
+ 4. the remaining white pointers are considered orphan and reported
+ via /sys/kernel/debug/memleak
+
+
+Improvements
+------------
+
+Because the Linux kernel calculates many pointers at run-time via the
+container_of macro (see the lists implementation), a lot of false
+positives would be reported. This tool re-writes the container_of
+macro so that the offset and type information is stored in the
+.init.memleak_offsets section. The memleak_init() function creates a
+radix tree with corresponding offsets for every encountered block
+type. The memory allocations hook stores the pointer address together
+with its aliases based on the type of the allocated block.
+
+While one level of offsets should be enough for most cases, a second
+level, i.e. container_of(container_of(...)), can be enabled via the
+configuration options (one false positive is the "struct socket_alloc"
+allocation in the sock_alloc_inode() function).
+
+Some allocated memory blocks have pointers stored in the kernel's
+internal data structures and they cannot be detected as orphans. To
+avoid this, kmemleak can also store the number of values equal to the
+pointer (or aliases) that need to be found so that the block is not
+considered a leak. One example is __vmalloc().
+
+
+Limitations and Drawbacks
+-------------------------
+
+The biggest drawback is the reduced performance of memory allocation
+and freeing. To avoid other penalties, the memory scanning is only
+performed when the /sys/kernel/debug/memleak file is read. Anyway,
+this tool is intended for debugging purposes where the performance
+might not be the most important requirement.
+
+Kmemleak currently approximates the type id using the sizeof()
+compiler built-in function. This is not accurate and can lead to false
+negatives. The aim is to gradually change the kernel and kmemleak to
+do more precise type identification.
+
+Another source of false negatives is the data stored in non-pointer
+values. Together with the more precise type identification, kmemleak
+could only scan the pointer members in the allocated structures.
+
+The tool can report false positives. These are cases where an
+allocated block doesn't need to be freed (some cases in the init_call
+functions), the pointer is calculated by other methods than the
+container_of macro or the pointer is stored in a location not scanned
+by kmemleak. If the "member" argument in the offsetof(type, member)
+call is not constant, kmemleak considers the offset as zero since it
+cannot be determined at compilation time.
+
+Page allocations and ioremap are not tracked. Only the ARM and i386
+architectures are currently supported.
+
+
+Kmemleak API
+------------
+
+See the include/linux/memleak.h header for the functions prototype.
+
+memleak_init - initialize kmemleak
+memleak_alloc - notify of a memory block allocation
+memleak_free - notify of a memory block freeing
+memleak_padding - mark the boundaries of the data inside the block
+memleak_not_leak - mark a pointer as not a leak
+memleak_ignore - do not scan or report a pointer as leak
+memleak_scan_area - add scan areas inside a memory block
+memleak_insert_aliases - add aliases for a given type
+memleak_erase - erase an old value in a pointer variable
+memleak_typeid_raw - set the typeid for an allocated block
+memleak_container - statically declare a pointer alias
+memleak_typeid - set the typeid for an allocated block (takes
+ a type rather than typeid as argument)
+
+
+Dealing with false positives/negatives
+--------------------------------------
+
+To reduce the false negatives, kmemleak provides the memleak_ignore,
+memleak_scan_area and memleak_erase functions. The task stacks also
+increase the amount of false negatives and their scanning is not
+enabled by default.
+
+To eliminate the false positives caused by code allocating a different
+size from the object one (either for alignment or for extra memory
+after the end of the structure), kmemleak provides the memleak_padding
+and memleak_typeid functions.
+
+For pointers known not to be leaks, kmemleak provides the
+memleak_not_leak function. The memleak_ignore could also be used if
+the memory block is known not to contain other pointers as it will no
+longer be scanned.
From: Catalin Marinas <[email protected]>
This patch adds the callbacks to memleak_(alloc|free) functions from
kmalloc/kfree, kmem_cache_(alloc|free), vmalloc/vfree etc.
Signed-off-by: Catalin Marinas <[email protected]>
---
include/linux/slab.h | 6 ++++++
mm/page_alloc.c | 2 ++
mm/slab.c | 19 +++++++++++++++++--
mm/vmalloc.c | 22 ++++++++++++++++++++--
4 files changed, 45 insertions(+), 4 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 45ad55b..e3f5945 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -133,6 +133,8 @@ #endif
*/
static inline void *kmalloc(size_t size, gfp_t flags)
{
+#ifndef CONFIG_DEBUG_MEMLEAK
+ /* this block removes the size information needed by kmemleak */
if (__builtin_constant_p(size)) {
int i = 0;
#define CACHE(x) \
@@ -151,6 +153,7 @@ found:
malloc_sizes[i].cs_dmacachep :
malloc_sizes[i].cs_cachep, flags);
}
+#endif
return __kmalloc(size, flags);
}
@@ -163,6 +166,8 @@ extern void *__kzalloc(size_t, gfp_t);
*/
static inline void *kzalloc(size_t size, gfp_t flags)
{
+#ifndef CONFIG_DEBUG_MEMLEAK
+ /* this block removes the size information needed by kmemleak */
if (__builtin_constant_p(size)) {
int i = 0;
#define CACHE(x) \
@@ -181,6 +186,7 @@ found:
malloc_sizes[i].cs_dmacachep :
malloc_sizes[i].cs_cachep, flags);
}
+#endif
return __kzalloc(size, flags);
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 54a4f53..bdf6445 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2450,6 +2450,8 @@ void *__init alloc_large_system_hash(con
if (_hash_mask)
*_hash_mask = (1 << log2qty) - 1;
+ memleak_alloc(table, size, 1);
+
return table;
}
diff --git a/mm/slab.c b/mm/slab.c
index 21ba060..0dd753c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2446,6 +2446,9 @@ static struct slab *alloc_slabmgmt(struc
/* Slab management obj is off-slab. */
slabp = kmem_cache_alloc_node(cachep->slabp_cache,
local_flags, nodeid);
+ /* only scan the list member to avoid false negatives */
+ memleak_scan_area(slabp, offsetof(struct slab, list),
+ sizeof(struct list_head));
if (!slabp)
return NULL;
} else {
@@ -2986,6 +2989,8 @@ #endif
STATS_INC_ALLOCMISS(cachep);
objp = cache_alloc_refill(cachep, flags);
}
+ /* avoid false negatives */
+ memleak_erase(&ac->entry[ac->avail]);
return objp;
}
@@ -3002,6 +3007,7 @@ static __always_inline void *__cache_all
local_irq_restore(save_flags);
objp = cache_alloc_debugcheck_after(cachep, flags, objp,
caller);
+ memleak_alloc(objp, obj_size(cachep), 1);
prefetchw(objp);
return objp;
}
@@ -3193,6 +3199,7 @@ static inline void __cache_free(struct k
struct array_cache *ac = cpu_cache_get(cachep);
check_irq_off();
+ memleak_free(objp);
objp = cache_free_debugcheck(cachep, objp, __builtin_return_address(0));
if (cache_free_alien(cachep, objp))
@@ -3312,6 +3319,7 @@ void *kmem_cache_alloc_node(struct kmem_
ptr = cache_alloc_debugcheck_after(cachep, flags, ptr,
__builtin_return_address(0));
+ memleak_alloc(ptr, obj_size(cachep), 1);
return ptr;
}
@@ -3320,11 +3328,14 @@ EXPORT_SYMBOL(kmem_cache_alloc_node);
void *kmalloc_node(size_t size, gfp_t flags, int node)
{
struct kmem_cache *cachep;
+ void *ptr;
cachep = kmem_find_general_cachep(size, flags);
if (unlikely(cachep == NULL))
return NULL;
- return kmem_cache_alloc_node(cachep, flags, node);
+ ptr = kmem_cache_alloc_node(cachep, flags, node);
+ memleak_padding(ptr, 0, size);
+ return ptr;
}
EXPORT_SYMBOL(kmalloc_node);
#endif
@@ -3339,6 +3350,7 @@ static __always_inline void *__do_kmallo
void *caller)
{
struct kmem_cache *cachep;
+ void *ptr;
/* If you want to save a few bytes .text space: replace
* __ with kmem_.
@@ -3348,7 +3360,10 @@ static __always_inline void *__do_kmallo
cachep = __find_general_cachep(size, flags);
if (unlikely(cachep == NULL))
return NULL;
- return __cache_alloc(cachep, flags, caller);
+ ptr = __cache_alloc(cachep, flags, caller);
+ memleak_padding(ptr, 0, size);
+
+ return ptr;
}
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 266162d..a4d319f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -364,6 +364,9 @@ void __vunmap(void *addr, int deallocate
void vfree(void *addr)
{
BUG_ON(in_interrupt());
+
+ memleak_free(addr);
+
__vunmap(addr, 1);
}
EXPORT_SYMBOL(vfree);
@@ -463,7 +466,14 @@ fail:
void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot)
{
- return __vmalloc_area_node(area, gfp_mask, prot, -1);
+ void *addr = __vmalloc_area_node(area, gfp_mask, prot, -1);
+
+ /* this needs ref_count = 2 since vm_struct also contains a
+ * pointer to this address. The guard page is also subtracted
+ * from the size */
+ memleak_alloc(addr, area->size - PAGE_SIZE, 2);
+
+ return addr;
}
/**
@@ -482,6 +492,8 @@ void *__vmalloc_node(unsigned long size,
int node)
{
struct vm_struct *area;
+ void *addr;
+ unsigned long real_size = size;
size = PAGE_ALIGN(size);
if (!size || (size >> PAGE_SHIFT) > num_physpages)
@@ -491,7 +503,13 @@ void *__vmalloc_node(unsigned long size,
if (!area)
return NULL;
- return __vmalloc_area_node(area, gfp_mask, prot, node);
+ addr = __vmalloc_area_node(area, gfp_mask, prot, node);
+
+ /* this needs ref_count = 2 since the vm_struct also contains
+ a pointer to this address */
+ memleak_alloc(addr, real_size, 2);
+
+ return addr;
}
EXPORT_SYMBOL(__vmalloc_node);
From: Catalin Marinas <[email protected]>
This patch adds the CONFIG_DEBUG_KEEP_INIT option which preserves the
.init.text section after initialization. Memory leaks happening during this
phase can be more easily tracked.
Signed-off-by: Catalin Marinas <[email protected]>
---
include/linux/init.h | 5 +++++
lib/Kconfig.debug | 12 ++++++++++++
2 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/include/linux/init.h b/include/linux/init.h
index 6667785..4b2df24 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -40,8 +40,13 @@ #include <linux/compiler.h>
/* These are for everybody (although not all archs will actually
discard it in modules) */
+#ifdef CONFIG_DEBUG_KEEP_INIT
+#define __init
+#define __initdata
+#else
#define __init __attribute__ ((__section__ (".init.text")))
#define __initdata __attribute__ ((__section__ (".init.data")))
+#endif
#define __exitdata __attribute__ ((__section__(".exit.data")))
#define __exit_call __attribute_used__ __attribute__ ((__section__ (".exitcall.exit")))
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1786cb5..b36ac64 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -195,6 +195,18 @@ config DEBUG_MEMLEAK_REPORTS_NR
reading the /sys/kernel/debug/memleak file could lead to
some soft-locks.
+config DEBUG_KEEP_INIT
+ bool "Do not free the __init code/data"
+ default n
+ depends on DEBUG_MEMLEAK
+ help
+ This option moves the __init code/data out of the
+ .init.text/.init.data sections. It is useful for identifying
+ memory leaks happening during the kernel or modules
+ initialization.
+
+ If unsure, say N.
+
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
From: Catalin Marinas <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>
---
MAINTAINERS | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index 25cd707..ccb4b97 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1669,6 +1669,12 @@ L: [email protected]
W: http://www.kerneljanitors.org/
S: Maintained
+KERNEL MEMORY LEAK DETECTOR
+P: Catalin Marinas
+M: [email protected]
+W: http://www.procode.org/
+S: Maintained
+
KERNEL NFSD
P: Neil Brown
M: [email protected]
From: Catalin Marinas <[email protected]>
There are allocations for which the main pointer cannot be found but they
are not memory leaks. This patch fixes some of them.
Signed-off-by: Catalin Marinas <[email protected]>
---
drivers/base/platform.c | 3 +++
drivers/char/vt.c | 4 ++++
drivers/hwmon/w83627hf.c | 4 ++++
drivers/scsi/hosts.c | 3 +++
drivers/video/console/fbcon.c | 3 +++
fs/ext3/dir.c | 3 +++
ipc/util.c | 6 ++++++
kernel/params.c | 8 +++++++-
mm/slab.c | 4 ++++
net/core/dev.c | 6 ++++++
net/core/skbuff.c | 3 +++
net/ipv4/netfilter/ip_conntrack_core.c | 5 +++++
net/sched/sch_generic.c | 5 +++++
13 files changed, 56 insertions(+), 1 deletions(-)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 2b8755d..1521fe4 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -166,6 +166,9 @@ struct platform_device *platform_device_
struct platform_object *pa;
pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
+ /* kmemleak cannot guess the object type because the block
+ * size is different from the object size */
+ memleak_typeid(pa, struct platform_object);
if (pa) {
strcpy(pa->name, name);
pa->pdev.name = pa->name;
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index da7e66a..0451e06 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -2611,6 +2611,10 @@ static int __init con_init(void)
*/
for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
vc_cons[currcons].d = vc = alloc_bootmem(sizeof(struct vc_data));
+ /* kmemleak does not track the memory allocated via
+ * alloc_bootmem() but this block contains pointers to
+ * other blocks allocated via kmalloc */
+ memleak_alloc(vc, sizeof(struct vc_data), 1);
visual_init(vc, currcons, 1);
vc->vc_screenbuf = (unsigned short *)alloc_bootmem(vc->vc_screenbuf_size);
vc->vc_kmalloced = 0;
diff --git a/drivers/hwmon/w83627hf.c b/drivers/hwmon/w83627hf.c
index 79368d5..f952f02 100644
--- a/drivers/hwmon/w83627hf.c
+++ b/drivers/hwmon/w83627hf.c
@@ -1065,6 +1065,10 @@ static int w83627hf_detect(struct i2c_ad
err = -ENOMEM;
goto ERROR1;
}
+ /* the pointer to member is stored but the code doesn't use
+ * container_of for access and the alias need to be
+ * explicitely declared here */
+ memleak_container(struct w83627hf_data, client);
new_client = &data->client;
i2c_set_clientdata(new_client, data);
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index dfcb96f..9516d37 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -297,6 +297,9 @@ struct Scsi_Host *scsi_host_alloc(struct
shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
if (!shost)
return NULL;
+ /* kmemleak cannot guess the object type because the block
+ * size is different from the object size */
+ memleak_typeid(shost, struct Scsi_Host);
spin_lock_init(&shost->default_lock);
scsi_assign_lock(shost, &shost->default_lock);
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 390439b..284e34c 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -2479,6 +2479,9 @@ static int fbcon_set_font(struct vc_data
size = h * pitch * charcount;
new_data = kmalloc(FONT_EXTRA_WORDS * sizeof(int) + size, GFP_USER);
+ /* the stored pointer is different from the address of the
+ * allocated block because of padding */
+ memleak_padding(new_data, FONT_EXTRA_WORDS * sizeof(int), size);
if (!new_data)
return -ENOMEM;
diff --git a/fs/ext3/dir.c b/fs/ext3/dir.c
index fbb0d4e..a34814d 100644
--- a/fs/ext3/dir.c
+++ b/fs/ext3/dir.c
@@ -346,6 +346,9 @@ int ext3_htree_store_dirent(struct file
new_fn = kmalloc(len, GFP_KERNEL);
if (!new_fn)
return -ENOMEM;
+ /* kmemleak cannot guess the object type because the block
+ * size is different from the object size */
+ memleak_typeid(new_fn, struct fname);
memset(new_fn, 0, len);
new_fn->hash = hash;
new_fn->minor_hash = minor_hash;
diff --git a/ipc/util.c b/ipc/util.c
index 67b6d17..17cc294 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -388,6 +388,9 @@ void* ipc_rcu_alloc(int size)
*/
if (rcu_use_vmalloc(size)) {
out = vmalloc(HDRLEN_VMALLOC + size);
+ /* the stored pointer is different from the address of
+ * the allocated block because of padding */
+ memleak_padding(out, HDRLEN_VMALLOC, size);
if (out) {
out += HDRLEN_VMALLOC;
container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 1;
@@ -395,6 +398,9 @@ void* ipc_rcu_alloc(int size)
}
} else {
out = kmalloc(HDRLEN_KMALLOC + size, GFP_KERNEL);
+ /* the stored pointer is different from the address of
+ * the allocated block because of padding */
+ memleak_padding(out, HDRLEN_KMALLOC, size);
if (out) {
out += HDRLEN_KMALLOC;
container_of(out, struct ipc_rcu_hdr, data)->is_vmalloc = 0;
diff --git a/kernel/params.c b/kernel/params.c
index 91aea7a..b957b86 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -547,6 +547,7 @@ static void __init kernel_param_sysfs_se
unsigned int name_skip)
{
struct module_kobject *mk;
+ struct module_param_attrs *mp;
mk = kzalloc(sizeof(struct module_kobject), GFP_KERNEL);
BUG_ON(!mk);
@@ -556,8 +557,13 @@ static void __init kernel_param_sysfs_se
kobject_set_name(&mk->kobj, name);
kobject_register(&mk->kobj);
+ mp = param_sysfs_setup(mk, kparam, num_params, name_skip);
+ /* this structure is not freed but the pointer is
+ * lost. However, there are other pointers to its members and
+ * the object has to be kept */
+ memleak_not_leak(mp);
/* no need to keep the kobject if no parameter is exported */
- if (!param_sysfs_setup(mk, kparam, num_params, name_skip)) {
+ if (!mp) {
kobject_unregister(&mk->kobj);
kfree(mk);
}
diff --git a/mm/slab.c b/mm/slab.c
index 0dd753c..d96c6cf 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3419,6 +3419,10 @@ void *__alloc_percpu(size_t size)
memset(pdata->ptrs[i], 0, size);
}
+ /* the code below changes the value of the returned pointer
+ * and kmemleak cannot find the original value during
+ * scanning. It is marked as not being a leak */
+ memleak_not_leak(pdata);
/* Catch derefs w/o wrappers */
return (void *)(~(unsigned long)pdata);
diff --git a/net/core/dev.c b/net/core/dev.c
index d4a1ec3..66a5fff 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3204,6 +3204,12 @@ struct net_device *alloc_netdev(int size
dev = (struct net_device *)
(((long)p + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST);
dev->padded = (char *)dev - (char *)p;
+ /* kmemleak cannot guess the object type because the block
+ * size is different from the object size. The stored pointer
+ * is also different from the address of the allocated block
+ * because of padding */
+ memleak_padding(p, dev->padded, alloc_size - dev->padded);
+ memleak_typeid(p, struct net_device);
if (sizeof_priv)
dev->priv = netdev_priv(dev);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c54f366..6dc6854 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -151,6 +151,9 @@ struct sk_buff *__alloc_skb(unsigned int
/* Get the HEAD */
skb = kmem_cache_alloc(cache, gfp_mask & ~__GFP_DMA);
+ /* the skbuff_fclone_cache contains objects larger than
+ * "struct sk_buff" and kmemleak cannot guess the type */
+ memleak_typeid(skb, struct sk_buff);
if (!skb)
goto out;
diff --git a/net/ipv4/netfilter/ip_conntrack_core.c b/net/ipv4/netfilter/ip_conntrack_core.c
index aa45917..7e64fe0 100644
--- a/net/ipv4/netfilter/ip_conntrack_core.c
+++ b/net/ipv4/netfilter/ip_conntrack_core.c
@@ -654,6 +654,11 @@ struct ip_conntrack *ip_conntrack_alloc(
}
conntrack = kmem_cache_alloc(ip_conntrack_cachep, GFP_ATOMIC);
+ /* tuplehash_to_ctrack doesn't pass a constant argument to
+ * container_of and therefore the conntrack->tuplehash[].list
+ * aliases are ignored */
+ memleak_container(struct ip_conntrack, tuplehash[IP_CT_DIR_ORIGINAL]);
+ memleak_container(struct ip_conntrack, tuplehash[IP_CT_DIR_REPLY]);
if (!conntrack) {
DEBUGP("Can't allocate conntrack.\n");
return ERR_PTR(-ENOMEM);
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 0834c2e..2b07b4b 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -437,6 +437,11 @@ struct Qdisc *qdisc_alloc(struct net_dev
goto errout;
sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
sch->padded = (char *) sch - (char *) p;
+ /* kmemleak cannot guess the object type because the block
+ * size is different from the object size. The stored pointer
+ * is also different from the address of the allocated block
+ * because of padding */
+ memleak_padding(p, sch->padded, sizeof(struct Qdisc));
INIT_LIST_HEAD(&sch->list);
skb_queue_head_init(&sch->q);
From: Catalin Marinas <[email protected]>
This patch modifies the vmlinux.lds.S script and adds the backtrace support
for ARM to be used with kmemleak.
Signed-off-by: Catalin Marinas <[email protected]>
---
arch/arm/kernel/vmlinux.lds.S | 7 +++++++
include/asm-arm/processor.h | 12 ++++++++++++
2 files changed, 19 insertions(+), 0 deletions(-)
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 3ca574e..59976b8 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -67,6 +67,11 @@ #endif
__per_cpu_start = .;
*(.data.percpu)
__per_cpu_end = .;
+#ifdef CONFIG_DEBUG_MEMLEAK
+ __memleak_offsets_start = .;
+ *(.init.memleak_offsets)
+ __memleak_offsets_end = .;
+#endif
#ifndef CONFIG_XIP_KERNEL
__init_begin = _stext;
*(.init.data)
@@ -115,6 +120,7 @@ #endif
.data : AT(__data_loc) {
__data_start = .; /* address in memory */
+ _sdata = .;
/*
* first, the init task union, aligned
@@ -165,6 +171,7 @@ #endif
__bss_start = .; /* BSS */
*(.bss)
*(COMMON)
+ __bss_stop = .;
_end = .;
}
/* Stabs debugging sections. */
diff --git a/include/asm-arm/processor.h b/include/asm-arm/processor.h
index 04f4d34..34a3bb3 100644
--- a/include/asm-arm/processor.h
+++ b/include/asm-arm/processor.h
@@ -121,6 +121,18 @@ #define spin_lock_prefetch(x) do { } whi
#endif
+#ifdef CONFIG_FRAME_POINTER
+static inline unsigned long arch_call_address(void *frame)
+{
+ return *(unsigned long *)(frame - 4) - 4;
+}
+
+static inline void *arch_prev_frame(void *frame)
+{
+ return *(void **)(frame - 12);
+}
+#endif
+
#endif
#endif /* __ASM_ARM_PROCESSOR_H */
From: Catalin Marinas <[email protected]>
This patch only contains some very simple testing at the moment. Proper
testing will be needed.
Signed-off-by: Catalin Marinas <[email protected]>
---
lib/Kconfig.debug | 11 +++++++
mm/Makefile | 1 +
mm/memleak-test.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 101 insertions(+), 0 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b36ac64..64b6362 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -207,6 +207,17 @@ config DEBUG_KEEP_INIT
If unsure, say N.
+config DEBUG_MEMLEAK_TEST
+ tristate "Test the kernel memory leak detector"
+ default n
+ depends on DEBUG_MEMLEAK
+ help
+ Say Y or M here to build the test harness for the kernel
+ memory leak detector. At the moment, this option enables a
+ module that explicitly leaks memory.
+
+ If unsure, say N.
+
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT
diff --git a/mm/Makefile b/mm/Makefile
index edccbc0..fd46a73 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -24,3 +24,4 @@ obj-$(CONFIG_MEMORY_HOTPLUG) += memory_h
obj-$(CONFIG_FS_XIP) += filemap_xip.o
obj-$(CONFIG_MIGRATION) += migrate.o
obj-$(CONFIG_DEBUG_MEMLEAK) += memleak.o
+obj-$(CONFIG_DEBUG_MEMLEAK_TEST) += memleak-test.o
diff --git a/mm/memleak-test.c b/mm/memleak-test.c
new file mode 100644
index 0000000..8120223
--- /dev/null
+++ b/mm/memleak-test.c
@@ -0,0 +1,89 @@
+/*
+ * mm/memleak-test.c
+ *
+ * Copyright (C) 2006 ARM Limited
+ * Written by Catalin Marinas <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/list.h>
+
+#include <linux/memleak.h>
+
+struct test_node {
+ long header[25];
+ struct list_head list;
+ long footer[25];
+};
+
+static LIST_HEAD(test_list);
+
+/* Some very simple testing. This function needs to be extended for
+ * proper testing */
+static int __init memleak_test_init(void)
+{
+ struct test_node *elem;
+ int i;
+
+ printk(KERN_INFO "KMemLeak testing\n");
+
+ /* make some orphan objects */
+ kmalloc(32, GFP_KERNEL);
+ kmalloc(32, GFP_KERNEL);
+ kmalloc(1024, GFP_KERNEL);
+ kmalloc(1024, GFP_KERNEL);
+ kmalloc(2048, GFP_KERNEL);
+ kmalloc(2048, GFP_KERNEL);
+ kmalloc(4096, GFP_KERNEL);
+ kmalloc(4096, GFP_KERNEL);
+#ifndef CONFIG_MODULES
+ kmem_cache_alloc(files_cachep, GFP_KERNEL);
+ kmem_cache_alloc(files_cachep, GFP_KERNEL);
+#endif
+ vmalloc(64);
+ vmalloc(64);
+
+ /* add elements to a list. They should only appear as orphan
+ * after the module is removed */
+ for (i = 0; i < 10; i++) {
+ elem = kmalloc(sizeof(*elem), GFP_KERNEL);
+ if (!elem)
+ return -ENOMEM;
+ memset(elem, 0, sizeof(*elem));
+ INIT_LIST_HEAD(&elem->list);
+
+ list_add_tail(&elem->list, &test_list);
+ }
+
+ return 0;
+}
+module_init(memleak_test_init);
+
+static void __exit memleak_test_exit(void)
+{
+ struct test_node *elem, *tmp;
+
+ /* remove the list elements without actually freeing the memory */
+ list_for_each_entry_safe(elem, tmp, &test_list, list)
+ list_del(&elem->list);
+}
+module_exit(memleak_test_exit);
+
+MODULE_LICENSE("GPL");
Hi Catalin,
On 07/09/06, Catalin Marinas <[email protected]> wrote:
> This is a new version (0.10) of the kernel memory leak detector. See
> the Documentation/kmemleak.txt file for a more detailed
> description. The patches are downloadable from (the whole patch or the
> broken-out series):
>
> http://homepage.ntlworld.com/cmarinas/kmemleak/patch-2.6.18-rc6-kmemleak-0.10.bz2
I get a kernel panic
http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/panic.jpg
http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/kml-config
Regards,
Michal
--
Michal K. K. Piotrowski
LTG - Linux Testers Group
(http://www.stardust.webpages.pl/ltg/)
On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> I get a kernel panic
> http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/panic.jpg
>
> http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/kml-config
Well, you set CONFIG_DEBUG_MEMLEAK_HASH_BITS to 32, this means that
kmemleak needs to allocate (sizeof(void*) * 2^32) which is 16GB of
RAM. I think a maximum of 20 should be enough (I got acceptable
results with 16 hash bits, the default value, and it seemed to do
better with 18).
--
Catalin
On 07/09/06, Catalin Marinas <[email protected]> wrote:
> On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > I get a kernel panic
> > http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/panic.jpg
> >
> > http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/kml-config
>
> Well, you set CONFIG_DEBUG_MEMLEAK_HASH_BITS to 32, this means that
> kmemleak needs to allocate (sizeof(void*) * 2^32) which is 16GB of
> RAM. I think a maximum of 20 should be enough (I got acceptable
> results with 16 hash bits, the default value, and it seemed to do
> better with 18).
CONFIG_DEBUG_MEMLEAK=y
CONFIG_DEBUG_MEMLEAK_HASH_BITS=8
CONFIG_DEBUG_MEMLEAK_TRACE_LENGTH=12
CONFIG_DEBUG_MEMLEAK_PREINIT_OBJECTS=512
# CONFIG_DEBUG_MEMLEAK_SECONDARY_ALIASES is not set
# CONFIG_DEBUG_MEMLEAK_TASK_STACKS is not set
# CONFIG_DEBUG_MEMLEAK_ORPHAN_FREEING is not set
CONFIG_DEBUG_MEMLEAK_REPORTS_NR=100
# CONFIG_DEBUG_KEEP_INIT is not set
# CONFIG_DEBUG_MEMLEAK_TEST is not set
I still get a panic
>
> --
> Catalin
>
Regards,
Michal
--
Michal K. K. Piotrowski
LTG - Linux Testers Group
(http://www.stardust.webpages.pl/ltg/)
On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> On 07/09/06, Catalin Marinas <[email protected]> wrote:
> > On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > > I get a kernel panic
> > > http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/panic.jpg
> > >
> > > http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/kml-config
> >
> > Well, you set CONFIG_DEBUG_MEMLEAK_HASH_BITS to 32, this means that
> > kmemleak needs to allocate (sizeof(void*) * 2^32) which is 16GB of
> > RAM. I think a maximum of 20 should be enough (I got acceptable
> > results with 16 hash bits, the default value, and it seemed to do
> > better with 18).
>
> CONFIG_DEBUG_MEMLEAK=y
> CONFIG_DEBUG_MEMLEAK_HASH_BITS=8
> CONFIG_DEBUG_MEMLEAK_TRACE_LENGTH=12
> CONFIG_DEBUG_MEMLEAK_PREINIT_OBJECTS=512
> # CONFIG_DEBUG_MEMLEAK_SECONDARY_ALIASES is not set
> # CONFIG_DEBUG_MEMLEAK_TASK_STACKS is not set
> # CONFIG_DEBUG_MEMLEAK_ORPHAN_FREEING is not set
> CONFIG_DEBUG_MEMLEAK_REPORTS_NR=100
> # CONFIG_DEBUG_KEEP_INIT is not set
> # CONFIG_DEBUG_MEMLEAK_TEST is not set
>
> I still get a panic
Is it in the same place? What does the panic text say?
BTW, you should probably enable SECONDARY_ALIASES and TASK_STACKS
above to reduce the number of false positives.
--
Catalin
On 07/09/06, Catalin Marinas <[email protected]> wrote:
> On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > On 07/09/06, Catalin Marinas <[email protected]> wrote:
> > > On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > > > I get a kernel panic
> > > > http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/panic.jpg
> > > >
> > > > http://www.stardust.webpages.pl/files/o_bugs/kmemleak-0.10/kml-config
> > >
> > > Well, you set CONFIG_DEBUG_MEMLEAK_HASH_BITS to 32, this means that
> > > kmemleak needs to allocate (sizeof(void*) * 2^32) which is 16GB of
> > > RAM. I think a maximum of 20 should be enough (I got acceptable
> > > results with 16 hash bits, the default value, and it seemed to do
> > > better with 18).
> >
> > CONFIG_DEBUG_MEMLEAK=y
> > CONFIG_DEBUG_MEMLEAK_HASH_BITS=8
> > CONFIG_DEBUG_MEMLEAK_TRACE_LENGTH=12
> > CONFIG_DEBUG_MEMLEAK_PREINIT_OBJECTS=512
> > # CONFIG_DEBUG_MEMLEAK_SECONDARY_ALIASES is not set
> > # CONFIG_DEBUG_MEMLEAK_TASK_STACKS is not set
> > # CONFIG_DEBUG_MEMLEAK_ORPHAN_FREEING is not set
> > CONFIG_DEBUG_MEMLEAK_REPORTS_NR=100
> > # CONFIG_DEBUG_KEEP_INIT is not set
> > # CONFIG_DEBUG_MEMLEAK_TEST is not set
> >
> > I still get a panic
>
> Is it in the same place? What does the panic text say?
It's the same "kmemleak: cannot allocate the pointer hash" panic.
>
> BTW, you should probably enable SECONDARY_ALIASES and TASK_STACKS
> above to reduce the number of false positives.
>
> --
> Catalin
>
Regards,
Michal
--
Michal K. K. Piotrowski
LTG - Linux Testers Group
(http://www.stardust.webpages.pl/ltg/)
On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> On 07/09/06, Catalin Marinas <[email protected]> wrote:
> > On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > > CONFIG_DEBUG_MEMLEAK=y
> > > CONFIG_DEBUG_MEMLEAK_HASH_BITS=8
Have you tried 16? With 8, a negative argument is passed as order to
__get_free_pages(). I'll modify kmemleak to cope with this.
--
Catalin
On 07/09/06, Catalin Marinas <[email protected]> wrote:
> On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > On 07/09/06, Catalin Marinas <[email protected]> wrote:
> > > On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > > > CONFIG_DEBUG_MEMLEAK=y
> > > > CONFIG_DEBUG_MEMLEAK_HASH_BITS=8
>
> Have you tried 16?
No, I haven't.
> With 8, a negative argument is passed as order to
> __get_free_pages(). I'll modify kmemleak to cope with this.
>
> --
> Catalin
>
Regards,
Michal
--
Michal K. K. Piotrowski
LTG - Linux Testers Group
(http://www.stardust.webpages.pl/ltg/)
On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> On 07/09/06, Catalin Marinas <[email protected]> wrote:
> > On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > > On 07/09/06, Catalin Marinas <[email protected]> wrote:
> > > > On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > > > > CONFIG_DEBUG_MEMLEAK=y
> > > > > CONFIG_DEBUG_MEMLEAK_HASH_BITS=8
> >
> > Have you tried 16?
>
> No, I haven't.
8 hash bits would lead to a really slow hash table lookup since you
would only have 256 entries and it uses linked lists to deal with
collisions (you may have tens of thousands of pointers to be stored in
the hash). Anyway, I attach a patch which allows you to set small
values but it is highly unrecommended.
--
Catalin
On 07/09/06, Catalin Marinas <[email protected]> wrote:
> On 07/09/06, Michal Piotrowski <[email protected]> wrote:
> > On 07/09/06, Catalin Marinas <[email protected]> wrote:
> > > Have you tried 16?
> >
> > No, I haven't.
With DEBUG_MEMLEAK_HASH_BITS=16 system woks fine.
>
> 8 hash bits would lead to a really slow hash table lookup since you
> would only have 256 entries and it uses linked lists to deal with
> collisions (you may have tens of thousands of pointers to be stored in
> the hash). Anyway, I attach a patch which allows you to set small
> values but it is highly unrecommended.
How about documeting maxial "safe" values?
Something like
"If you have X MB/GB of RAM memory you can set Y
X | Y
256 MB | 25
512 MB | 26
1GB | 27
2GB | 28
4GB | 29"
>
> --
> Catalin
>
Regards,
Michal
--
Michal K. K. Piotrowski
LTG - Linux Testers Group
(http://www.stardust.webpages.pl/ltg/)
