summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Documentation/kernel-parameters.txt2
-rw-r--r--include/linux/debugobjects.h90
-rw-r--r--init/main.c3
-rw-r--r--lib/Kconfig.debug23
-rw-r--r--lib/Makefile1
-rw-r--r--lib/debugobjects.c890
-rw-r--r--mm/page_alloc.c10
-rw-r--r--mm/slab.c10
-rw-r--r--mm/slub.c3
-rw-r--r--mm/vmalloc.c2
10 files changed, 1030 insertions, 4 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0ba0861..a3c3544 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -561,6 +561,8 @@ and is between 256 and 4096 characters. It is defined in the file
1 will print _a lot_ more information - normally
only useful to kernel developers.
+ debug_objects [KNL] Enable object debugging
+
decnet.addr= [HW,NET]
Format: <area>[,<node>]
See also Documentation/networking/decnet.txt.
diff --git a/include/linux/debugobjects.h b/include/linux/debugobjects.h
new file mode 100644
index 0000000..8c243aa
--- /dev/null
+++ b/include/linux/debugobjects.h
@@ -0,0 +1,90 @@
+#ifndef _LINUX_DEBUGOBJECTS_H
+#define _LINUX_DEBUGOBJECTS_H
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+
+enum debug_obj_state {
+ ODEBUG_STATE_NONE,
+ ODEBUG_STATE_INIT,
+ ODEBUG_STATE_INACTIVE,
+ ODEBUG_STATE_ACTIVE,
+ ODEBUG_STATE_DESTROYED,
+ ODEBUG_STATE_NOTAVAILABLE,
+ ODEBUG_STATE_MAX,
+};
+
+struct debug_obj_descr;
+
+/**
+ * struct debug_obj - representaion of an tracked object
+ * @node: hlist node to link the object into the tracker list
+ * @state: tracked object state
+ * @object: pointer to the real object
+ * @descr: pointer to an object type specific debug description structure
+ */
+struct debug_obj {
+ struct hlist_node node;
+ enum debug_obj_state state;
+ void *object;
+ struct debug_obj_descr *descr;
+};
+
+/**
+ * struct debug_obj_descr - object type specific debug description structure
+ * @name: name of the object typee
+ * @fixup_init: fixup function, which is called when the init check
+ * fails
+ * @fixup_activate: fixup function, which is called when the activate check
+ * fails
+ * @fixup_destroy: fixup function, which is called when the destroy check
+ * fails
+ * @fixup_free: fixup function, which is called when the free check
+ * fails
+ */
+struct debug_obj_descr {
+ const char *name;
+
+ int (*fixup_init) (void *addr, enum debug_obj_state state);
+ int (*fixup_activate) (void *addr, enum debug_obj_state state);
+ int (*fixup_destroy) (void *addr, enum debug_obj_state state);
+ int (*fixup_free) (void *addr, enum debug_obj_state state);
+};
+
+#ifdef CONFIG_DEBUG_OBJECTS
+extern void debug_object_init (void *addr, struct debug_obj_descr *descr);
+extern void
+debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr);
+extern void debug_object_activate (void *addr, struct debug_obj_descr *descr);
+extern void debug_object_deactivate(void *addr, struct debug_obj_descr *descr);
+extern void debug_object_destroy (void *addr, struct debug_obj_descr *descr);
+extern void debug_object_free (void *addr, struct debug_obj_descr *descr);
+
+extern void debug_objects_early_init(void);
+extern void debug_objects_mem_init(void);
+#else
+static inline void
+debug_object_init (void *addr, struct debug_obj_descr *descr) { }
+static inline void
+debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) { }
+static inline void
+debug_object_activate (void *addr, struct debug_obj_descr *descr) { }
+static inline void
+debug_object_deactivate(void *addr, struct debug_obj_descr *descr) { }
+static inline void
+debug_object_destroy (void *addr, struct debug_obj_descr *descr) { }
+static inline void
+debug_object_free (void *addr, struct debug_obj_descr *descr) { }
+
+static inline void debug_objects_early_init(void) { }
+static inline void debug_objects_mem_init(void) { }
+#endif
+
+#ifdef CONFIG_DEBUG_OBJECTS_FREE
+extern void debug_check_no_obj_freed(const void *address, unsigned long size);
+#else
+static inline void
+debug_check_no_obj_freed(const void *address, unsigned long size) { }
+#endif
+
+#endif
diff --git a/init/main.c b/init/main.c
index dff253c..a87d4ca5 100644
--- a/init/main.c
+++ b/init/main.c
@@ -52,6 +52,7 @@
#include <linux/unwind.h>
#include <linux/buffer_head.h>
#include <linux/debug_locks.h>
+#include <linux/debugobjects.h>
#include <linux/lockdep.h>
#include <linux/pid_namespace.h>
#include <linux/device.h>
@@ -543,6 +544,7 @@ asmlinkage void __init start_kernel(void)
*/
unwind_init();
lockdep_init();
+ debug_objects_early_init();
cgroup_init_early();
local_irq_disable();
@@ -638,6 +640,7 @@ asmlinkage void __init start_kernel(void)
enable_debug_pagealloc();
cpu_hotplug_init();
kmem_cache_init();
+ debug_objects_mem_init();
idr_init_cache();
setup_per_cpu_pageset();
numa_policy_init();
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 754cc00..3e132b0 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -194,6 +194,29 @@ config TIMER_STATS
(it defaults to deactivated on bootup and will only be activated
if some application like powertop activates it explicitly).
+config DEBUG_OBJECTS
+ bool "Debug object operations"
+ depends on DEBUG_KERNEL
+ help
+ If you say Y here, additional code will be inserted into the
+ kernel to track the life time of various objects and validate
+ the operations on those objects.
+
+config DEBUG_OBJECTS_SELFTEST
+ bool "Debug objects selftest"
+ depends on DEBUG_OBJECTS
+ help
+ This enables the selftest of the object debug code.
+
+config DEBUG_OBJECTS_FREE
+ bool "Debug objects in freed memory"
+ depends on DEBUG_OBJECTS
+ help
+ This enables checks whether a k/v free operation frees an area
+ which contains an object which has not been deactivated
+ properly. This can make kmalloc/kfree-intensive workloads
+ much slower.
+
config DEBUG_SLAB
bool "Debug slab memory allocations"
depends on DEBUG_KERNEL && SLAB
diff --git a/lib/Makefile b/lib/Makefile
index 0ae4eb0..74b0cfb 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o
obj-$(CONFIG_PLIST) += plist.o
obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
obj-$(CONFIG_DEBUG_LIST) += list_debug.o
+obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o
ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
lib-y += dec_and_lock.o
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
new file mode 100644
index 0000000..a76a5e1
--- /dev/null
+++ b/lib/debugobjects.c
@@ -0,0 +1,890 @@
+/*
+ * Generic infrastructure for lifetime debugging of objects.
+ *
+ * Started by Thomas Gleixner
+ *
+ * Copyright (C) 2008, Thomas Gleixner <tglx@linutronix.de>
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+#include <linux/debugobjects.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/hash.h>
+
+#define ODEBUG_HASH_BITS 14
+#define ODEBUG_HASH_SIZE (1 << ODEBUG_HASH_BITS)
+
+#define ODEBUG_POOL_SIZE 512
+#define ODEBUG_POOL_MIN_LEVEL 256
+
+#define ODEBUG_CHUNK_SHIFT PAGE_SHIFT
+#define ODEBUG_CHUNK_SIZE (1 << ODEBUG_CHUNK_SHIFT)
+#define ODEBUG_CHUNK_MASK (~(ODEBUG_CHUNK_SIZE - 1))
+
+struct debug_bucket {
+ struct hlist_head list;
+ spinlock_t lock;
+};
+
+static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
+
+static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE];
+
+static DEFINE_SPINLOCK(pool_lock);
+
+static HLIST_HEAD(obj_pool);
+
+static int obj_pool_min_free = ODEBUG_POOL_SIZE;
+static int obj_pool_free = ODEBUG_POOL_SIZE;
+static int obj_pool_used;
+static int obj_pool_max_used;
+static struct kmem_cache *obj_cache;
+
+static int debug_objects_maxchain __read_mostly;
+static int debug_objects_fixups __read_mostly;
+static int debug_objects_warnings __read_mostly;
+static int debug_objects_enabled __read_mostly;
+static struct debug_obj_descr *descr_test __read_mostly;
+
+static int __init enable_object_debug(char *str)
+{
+ debug_objects_enabled = 1;
+ return 0;
+}
+early_param("debug_objects", enable_object_debug);
+
+static const char *obj_states[ODEBUG_STATE_MAX] = {
+ [ODEBUG_STATE_NONE] = "none",
+ [ODEBUG_STATE_INIT] = "initialized",
+ [ODEBUG_STATE_INACTIVE] = "inactive",
+ [ODEBUG_STATE_ACTIVE] = "active",
+ [ODEBUG_STATE_DESTROYED] = "destroyed",
+ [ODEBUG_STATE_NOTAVAILABLE] = "not available",
+};
+
+static int fill_pool(void)
+{
+ gfp_t gfp = GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN;
+ struct debug_obj *new;
+
+ if (likely(obj_pool_free >= ODEBUG_POOL_MIN_LEVEL))
+ return obj_pool_free;
+
+ if (unlikely(!obj_cache))
+ return obj_pool_free;
+
+ while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) {
+
+ new = kmem_cache_zalloc(obj_cache, gfp);
+ if (!new)
+ return obj_pool_free;
+
+ spin_lock(&pool_lock);
+ hlist_add_head(&new->node, &obj_pool);
+ obj_pool_free++;
+ spin_unlock(&pool_lock);
+ }
+ return obj_pool_free;
+}
+
+/*
+ * Lookup an object in the hash bucket.
+ */
+static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b)
+{
+ struct hlist_node *node;
+ struct debug_obj *obj;
+ int cnt = 0;
+
+ hlist_for_each_entry(obj, node, &b->list, node) {
+ cnt++;
+ if (obj->object == addr)
+ return obj;
+ }
+ if (cnt > debug_objects_maxchain)
+ debug_objects_maxchain = cnt;
+
+ return NULL;
+}
+
+/*
+ * Allocate a new object. If the pool is empty and no refill possible,
+ * switch off the debugger.
+ */
+static struct debug_obj *
+alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
+{
+ struct debug_obj *obj = NULL;
+ int retry = 0;
+
+repeat:
+ spin_lock(&pool_lock);
+ if (obj_pool.first) {
+ obj = hlist_entry(obj_pool.first, typeof(*obj), node);
+
+ obj->object = addr;
+ obj->descr = descr;
+ obj->state = ODEBUG_STATE_NONE;
+ hlist_del(&obj->node);
+
+ hlist_add_head(&obj->node, &b->list);
+
+ obj_pool_used++;
+ if (obj_pool_used > obj_pool_max_used)
+ obj_pool_max_used = obj_pool_used;
+
+ obj_pool_free--;
+ if (obj_pool_free < obj_pool_min_free)
+ obj_pool_min_free = obj_pool_free;
+ }
+ spin_unlock(&pool_lock);
+
+ if (fill_pool() && !obj && !retry++)
+ goto repeat;
+
+ return obj;
+}
+
+/*
+ * Put the object back into the pool or give it back to kmem_cache:
+ */
+static void free_object(struct debug_obj *obj)
+{
+ unsigned long idx = (unsigned long)(obj - obj_static_pool);
+
+ if (obj_pool_free < ODEBUG_POOL_SIZE || idx < ODEBUG_POOL_SIZE) {
+ spin_lock(&pool_lock);
+ hlist_add_head(&obj->node, &obj_pool);
+ obj_pool_free++;
+ obj_pool_used--;
+ spin_unlock(&pool_lock);
+ } else {
+ spin_lock(&pool_lock);
+ obj_pool_used--;
+ spin_unlock(&pool_lock);
+ kmem_cache_free(obj_cache, obj);
+ }
+}
+
+/*
+ * We run out of memory. That means we probably have tons of objects
+ * allocated.
+ */
+static void debug_objects_oom(void)
+{
+ struct debug_bucket *db = obj_hash;
+ struct hlist_node *node, *tmp;
+ struct debug_obj *obj;
+ unsigned long flags;
+ int i;
+
+ printk(KERN_WARNING "ODEBUG: Out of memory. ODEBUG disabled\n");
+
+ for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
+ spin_lock_irqsave(&db->lock, flags);
+ hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
+ hlist_del(&obj->node);
+ free_object(obj);
+ }
+ spin_unlock_irqrestore(&db->lock, flags);
+ }
+}
+
+/*
+ * We use the pfn of the address for the hash. That way we can check
+ * for freed objects simply by checking the affected bucket.
+ */
+static struct debug_bucket *get_bucket(unsigned long addr)
+{
+ unsigned long hash;
+
+ hash = hash_long((addr >> ODEBUG_CHUNK_SHIFT), ODEBUG_HASH_BITS);
+ return &obj_hash[hash];
+}
+
+static void debug_print_object(struct debug_obj *obj, char *msg)
+{
+ static int limit;
+
+ if (limit < 5 && obj->descr != descr_test) {
+ limit++;
+ printk(KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
+ obj_states[obj->state], obj->descr->name);
+ WARN_ON(1);
+ }
+ debug_objects_warnings++;
+}
+
+/*
+ * Try to repair the damage, so we have a better chance to get useful
+ * debug output.
+ */
+static void
+debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state),
+ void * addr, enum debug_obj_state state)
+{
+ if (fixup)
+ debug_objects_fixups += fixup(addr, state);
+}
+
+static void debug_object_is_on_stack(void *addr, int onstack)
+{
+ void *stack = current->stack;
+ int is_on_stack;
+ static int limit;
+
+ if (limit > 4)
+ return;
+
+ is_on_stack = (addr >= stack && addr < (stack + THREAD_SIZE));
+
+ if (is_on_stack == onstack)
+ return;
+
+ limit++;
+ if (is_on_stack)
+ printk(KERN_WARNING
+ "ODEBUG: object is on stack, but not annotated\n");
+ else
+ printk(KERN_WARNING
+ "ODEBUG: object is not on stack, but annotated\n");
+ WARN_ON(1);
+}
+
+static void
+__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack)
+{
+ enum debug_obj_state state;
+ struct debug_bucket *db;
+ struct debug_obj *obj;
+ unsigned long flags;
+
+ db = get_bucket((unsigned long) addr);
+
+ spin_lock_irqsave(&db->lock, flags);
+
+ obj = lookup_object(addr, db);
+ if (!obj) {
+ obj = alloc_object(addr, db, descr);
+ if (!obj) {
+ debug_objects_enabled = 0;
+ spin_unlock_irqrestore(&db->lock, flags);
+ debug_objects_oom();
+ return;
+ }
+ debug_object_is_on_stack(addr, onstack);
+ }
+
+ switch (obj->state) {
+ case ODEBUG_STATE_NONE:
+ case ODEBUG_STATE_INIT:
+ case ODEBUG_STATE_INACTIVE:
+ obj->state = ODEBUG_STATE_INIT;
+ break;
+
+ case ODEBUG_STATE_ACTIVE:
+ debug_print_object(obj, "init");
+ state = obj->state;
+ spin_unlock_irqrestore(&db->lock, flags);
+ debug_object_fixup(descr->fixup_init, addr, state);
+ return;
+
+ case ODEBUG_STATE_DESTROYED:
+ debug_print_object(obj, "init");
+ break;
+ default:
+ break;
+ }
+
+ spin_unlock_irqrestore(&db->lock, flags);
+}
+
+/**
+ * debug_object_init - debug checks when an object is initialized
+ * @addr: address of the object
+ * @descr: pointer to an object specific debug description structure
+ */
+void debug_object_init(void *addr, struct debug_obj_descr *descr)
+{
+ if (!debug_objects_enabled)
+ return;
+
+ __debug_object_init(addr, descr, 0);
+}
+
+/**
+ * debug_object_init_on_stack - debug checks when an object on stack is
+ * initialized
+ * @addr: address of the object
+ * @descr: pointer to an object specific debug description structure
+ */
+void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr)
+{
+ if (!debug_objects_enabled)
+ return;
+
+ __debug_object_init(addr, descr, 1);
+}
+
+/**
+ * debug_object_activate - debug checks when an object is activated
+ * @addr: address of the object
+ * @descr: pointer to an object specific debug description structure
+ */
+void debug_object_activate(void *addr, struct debug_obj_descr *descr)
+{
+ enum debug_obj_state state;
+ struct debug_bucket *db;
+ struct debug_obj *obj;
+ unsigned long flags;
+
+ if (!debug_objects_enabled)
+ return;
+
+ db = get_bucket((unsigned long) addr);
+
+ spin_lock_irqsave(&db->lock, flags);
+
+ obj = lookup_object(addr, db);
+ if (obj) {
+ switch (obj->state) {
+ case ODEBUG_STATE_INIT:
+ case ODEBUG_STATE_INACTIVE:
+ obj->state = ODEBUG_STATE_ACTIVE;
+ break;
+
+ case ODEBUG_STATE_ACTIVE:
+ debug_print_object(obj, "activate");
+ state = obj->state;
+ spin_unlock_irqrestore(&db->lock, flags);
+ debug_object_fixup(descr->fixup_activate, addr, state);
+ return;
+
+ case ODEBUG_STATE_DESTROYED:
+ debug_print_object(obj, "activate");
+ break;
+ default:
+ break;
+ }
+ spin_unlock_irqrestore(&db->lock, flags);
+ return;
+ }
+
+ spin_unlock_irqrestore(&db->lock, flags);
+ /*
+ * This happens when a static object is activated. We
+ * let the type specific code decide whether this is
+ * true or not.
+ */
+ debug_object_fixup(descr->fixup_activate, addr,
+ ODEBUG_STATE_NOTAVAILABLE);
+}
+
+/**
+ * debug_object_deactivate - debug checks when an object is deactivated
+ * @addr: address of the object
+ * @descr: pointer to an object specific debug description structure
+ */
+void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
+{
+ struct debug_bucket *db;
+ struct debug_obj *obj;
+ unsigned long flags;
+
+ if (!debug_objects_enabled)
+ return;
+
+ db = get_bucket((unsigned long) addr);
+
+ spin_lock_irqsave(&db->lock, flags);
+
+ obj = lookup_object(addr, db);
+ if (obj) {
+ switch (obj->state) {
+ case ODEBUG_STATE_INIT:
+ case ODEBUG_STATE_INACTIVE:
+ case ODEBUG_STATE_ACTIVE:
+ obj->state = ODEBUG_STATE_INACTIVE;
+ break;
+
+ case ODEBUG_STATE_DESTROYED:
+ debug_print_object(obj, "deactivate");
+ break;
+ default:
+ break;
+ }
+ } else {
+ struct debug_obj o = { .object = addr,
+ .state = ODEBUG_STATE_NOTAVAILABLE,
+ .descr = descr };
+
+ debug_print_object(&o, "deactivate");
+ }
+
+ spin_unlock_irqrestore(&db->lock, flags);
+}
+
+/**
+ * debug_object_destroy - debug checks when an object is destroyed
+ * @addr: address of the object
+ * @descr: pointer to an object specific debug description structure
+ */
+void debug_object_destroy(void *addr, struct debug_obj_descr *descr)
+{
+ enum debug_obj_state state;
+ struct debug_bucket *db;
+ struct debug_obj *obj;
+ unsigned long flags;
+
+ if (!debug_objects_enabled)
+ return;
+
+ db = get_bucket((unsigned long) addr);
+
+ spin_lock_irqsave(&db->lock, flags);
+
+ obj = lookup_object(addr, db);
+ if (!obj)
+ goto out_unlock;
+
+ switch (obj->state) {
+ case ODEBUG_STATE_NONE:
+ case ODEBUG_STATE_INIT:
+ case ODEBUG_STATE_INACTIVE:
+ obj->state = ODEBUG_STATE_DESTROYED;
+ break;
+ case ODEBUG_STATE_ACTIVE:
+ debug_print_object(obj, "destroy");
+ state = obj->state;
+ spin_unlock_irqrestore(&db->lock, flags);
+ debug_object_fixup(descr->fixup_destroy, addr, state);
+ return;
+
+ case ODEBUG_STATE_DESTROYED:
+ debug_print_object(obj, "destroy");
+ break;
+ default:
+ break;
+ }
+out_unlock:
+ spin_unlock_irqrestore(&db->lock, flags);
+}
+
+/**
+ * debug_object_free - debug checks when an object is freed
+ * @addr: address of the object
+ * @descr: pointer to an object specific debug description structure
+ */
+void debug_object_free(void *addr, struct debug_obj_descr *descr)
+{
+ enum debug_obj_state state;
+ struct debug_bucket *db;
+ struct debug_obj *obj;
+ unsigned long flags;
+
+ if (!debug_objects_enabled)
+ return;
+
+ db = get_bucket((unsigned long) addr);
+
+ spin_lock_irqsave(&db->lock, flags);
+
+ obj = lookup_object(addr, db);
+ if (!obj)
+ goto out_unlock;
+
+ switch (obj->state) {
+ case ODEBUG_STATE_ACTIVE:
+ debug_print_object(obj, "free");
+ state = obj->state;
+ spin_unlock_irqrestore(&db->lock, flags);
+ debug_object_fixup(descr->fixup_free, addr, state);
+ return;
+ default:
+ hlist_del(&obj->node);
+ free_object(obj);
+ break;
+ }
+out_unlock:
+ spin_unlock_irqrestore(&db->lock, flags);
+}
+
+#ifdef CONFIG_DEBUG_OBJECTS_FREE
+static void __debug_check_no_obj_freed(const void *address, unsigned long size)
+{
+ unsigned long flags, oaddr, saddr, eaddr, paddr, chunks;
+ struct hlist_node *node, *tmp;
+ struct debug_obj_descr *descr;
+ enum debug_obj_state state;
+ struct debug_bucket *db;
+ struct debug_obj *obj;
+ int cnt;
+
+ saddr = (unsigned long) address;
+ eaddr = saddr + size;
+ paddr = saddr & ODEBUG_CHUNK_MASK;
+ chunks = ((eaddr - paddr) + (ODEBUG_CHUNK_SIZE - 1));
+ chunks >>= ODEBUG_CHUNK_SHIFT;
+
+ for (;chunks > 0; chunks--, paddr += ODEBUG_CHUNK_SIZE) {
+ db = get_bucket(paddr);
+
+repeat:
+ cnt = 0;
+ spin_lock_irqsave(&db->lock, flags);
+ hlist_for_each_entry_safe(obj, node, tmp, &db->list, node) {
+ cnt++;
+ oaddr = (unsigned long) obj->object;
+ if (oaddr < saddr || oaddr >= eaddr)
+ continue;
+
+ switch (obj->state) {
+ case ODEBUG_STATE_ACTIVE:
+ debug_print_object(obj, "free");
+ descr = obj->descr;
+ state = obj->state;
+ spin_unlock_irqrestore(&db->lock, flags);
+ debug_object_fixup(descr->fixup_free,
+ (void *) oaddr, state);
+ goto repeat;
+ default:
+ hlist_del(&obj->node);
+ free_object(obj);
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&db->lock, flags);
+ if (cnt > debug_objects_maxchain)
+ debug_objects_maxchain = cnt;
+ }
+}
+
+void debug_check_no_obj_freed(const void *address, unsigned long size)
+{
+ if (debug_objects_enabled)
+ __debug_check_no_obj_freed(address, size);
+}
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+
+static int debug_stats_show(struct seq_file *m, void *v)
+{
+ seq_printf(m, "max_chain :%d\n", debug_objects_maxchain);
+ seq_printf(m, "warnings :%d\n", debug_objects_warnings);
+ seq_printf(m, "fixups :%d\n", debug_objects_fixups);
+ seq_printf(m, "pool_free :%d\n", obj_pool_free);
+ seq_printf(m, "pool_min_free :%d\n", obj_pool_min_free);
+ seq_printf(m, "pool_used :%d\n", obj_pool_used);
+ seq_printf(m, "pool_max_used :%d\n", obj_pool_max_used);
+ return 0;
+}
+
+static int debug_stats_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, debug_stats_show, NULL);
+}
+
+static const struct file_operations debug_stats_fops = {
+ .open = debug_stats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init debug_objects_init_debugfs(void)
+{
+ struct dentry *dbgdir, *dbgstats;
+
+ if (!debug_objects_enabled)
+ return 0;
+
+ dbgdir = debugfs_create_dir("debug_objects", NULL);
+ if (!dbgdir)
+ return -ENOMEM;
+
+ dbgstats = debugfs_create_file("stats", 0444, dbgdir, NULL,
+ &debug_stats_fops);
+ if (!dbgstats)
+ goto err;
+
+ return 0;
+
+err:
+ debugfs_remove(dbgdir);
+
+ return -ENOMEM;
+}
+__initcall(debug_objects_init_debugfs);
+
+#else
+static inline void debug_objects_init_debugfs(void) { }
+#endif
+
+#ifdef CONFIG_DEBUG_OBJECTS_SELFTEST
+
+/* Random data structure for the self test */
+struct self_test {
+ unsigned long dummy1[6];
+ int static_init;
+ unsigned long dummy2[3];
+};
+
+static __initdata struct debug_obj_descr descr_type_test;
+
+/*
+ * fixup_init is called when:
+ * - an active object is initialized
+ */
+static int __init fixup_init(void *addr, enum debug_obj_state state)
+{
+ struct self_test *obj = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_ACTIVE:
+ debug_object_deactivate(obj, &descr_type_test);
+ debug_object_init(obj, &descr_type_test);
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * fixup_activate is called when:
+ * - an active object is activated
+ * - an unknown object is activated (might be a statically initialized object)
+ */
+static int __init fixup_activate(void *addr, enum debug_obj_state state)
+{
+ struct self_test *obj = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_NOTAVAILABLE:
+ if (obj->static_init == 1) {
+ debug_object_init(obj, &descr_type_test);
+ debug_object_activate(obj, &descr_type_test);
+ /*
+ * Real code should return 0 here ! This is
+ * not a fixup of some bad behaviour. We
+ * merily call the debug_init function to keep
+ * track of the object.
+ */
+ return 1;
+ } else {
+ /* Real code needs to emit a warning here */
+ }
+ return 0;
+
+ case ODEBUG_STATE_ACTIVE:
+ debug_object_deactivate(obj, &descr_type_test);
+ debug_object_activate(obj, &descr_type_test);
+ return 1;
+
+ default:
+ return 0;
+ }
+}
+
+/*
+ * fixup_destroy is called when:
+ * - an active object is destroyed
+ */
+static int __init fixup_destroy(void *addr, enum debug_obj_state state)
+{
+ struct self_test *obj = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_ACTIVE:
+ debug_object_deactivate(obj, &descr_type_test);
+ debug_object_destroy(obj, &descr_type_test);
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/*
+ * fixup_free is called when:
+ * - an active object is freed
+ */
+static int __init fixup_free(void *addr, enum debug_obj_state state)
+{
+ struct self_test *obj = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_ACTIVE:
+ debug_object_deactivate(obj, &descr_type_test);
+ debug_object_free(obj, &descr_type_test);
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static int
+check_results(void *addr, enum debug_obj_state state, int fixups, int warnings)
+{
+ struct debug_bucket *db;
+ struct debug_obj *obj;
+ unsigned long flags;
+ int res = -EINVAL;
+
+ db = get_bucket((unsigned long) addr);
+
+ spin_lock_irqsave(&db->lock, flags);
+
+ obj = lookup_object(addr, db);
+ if (!obj && state != ODEBUG_STATE_NONE) {
+ printk(KERN_ERR "ODEBUG: selftest object not found\n");
+ WARN_ON(1);
+ goto out;
+ }
+ if (obj && obj->state != state) {
+ printk(KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
+ obj->state, state);
+ WARN_ON(1);
+ goto out;
+ }
+ if (fixups != debug_objects_fixups) {
+ printk(KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
+ fixups, debug_objects_fixups);
+ WARN_ON(1);
+ goto out;
+ }
+ if (warnings != debug_objects_warnings) {
+ printk(KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
+ warnings, debug_objects_warnings);
+ WARN_ON(1);
+ goto out;
+ }
+ res = 0;
+out:
+ spin_unlock_irqrestore(&db->lock, flags);
+ if (res)
+ debug_objects_enabled = 0;
+ return res;
+}
+
+static __initdata struct debug_obj_descr descr_type_test = {
+ .name = "selftest",
+ .fixup_init = fixup_init,
+ .fixup_activate = fixup_activate,
+ .fixup_destroy = fixup_destroy,
+ .fixup_free = fixup_free,
+};
+
+static __initdata struct self_test obj = { .static_init = 0 };
+
+static void __init debug_objects_selftest(void)
+{
+ int fixups, oldfixups, warnings, oldwarnings;
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ fixups = oldfixups = debug_objects_fixups;
+ warnings = oldwarnings = debug_objects_warnings;
+ descr_test = &descr_type_test;
+
+ debug_object_init(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
+ goto out;
+ debug_object_activate(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
+ goto out;
+ debug_object_activate(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, ++warnings))
+ goto out;
+ debug_object_deactivate(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_INACTIVE, fixups, warnings))
+ goto out;
+ debug_object_destroy(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, warnings))
+ goto out;
+ debug_object_init(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
+ goto out;
+ debug_object_activate(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
+ goto out;
+ debug_object_deactivate(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_DESTROYED, fixups, ++warnings))
+ goto out;
+ debug_object_free(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
+ goto out;
+
+ obj.static_init = 1;
+ debug_object_activate(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_ACTIVE, ++fixups, warnings))
+ goto out;
+ debug_object_init(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_INIT, ++fixups, ++warnings))
+ goto out;
+ debug_object_free(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_NONE, fixups, warnings))
+ goto out;
+
+#ifdef CONFIG_DEBUG_OBJECTS_FREE
+ debug_object_init(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_INIT, fixups, warnings))
+ goto out;
+ debug_object_activate(&obj, &descr_type_test);
+ if (check_results(&obj, ODEBUG_STATE_ACTIVE, fixups, warnings))
+ goto out;
+ __debug_check_no_obj_freed(&obj, sizeof(obj));
+ if (check_results(&obj, ODEBUG_STATE_NONE, ++fixups, ++warnings))
+ goto out;
+#endif
+ printk(KERN_INFO "ODEBUG: selftest passed\n");
+
+out:
+ debug_objects_fixups = oldfixups;
+ debug_objects_warnings = oldwarnings;
+ descr_test = NULL;
+
+ local_irq_restore(flags);
+}
+#else
+static inline void debug_objects_selftest(void) { }
+#endif
+
+/*
+ * Called during early boot to initialize the hash buckets and link
+ * the static object pool objects into the poll list. After this call
+ * the object tracker is fully operational.
+ */
+void __init debug_objects_early_init(void)
+{
+ int i;
+
+ for (i = 0; i < ODEBUG_HASH_SIZE; i++)
+ spin_lock_init(&obj_hash[i].lock);
+
+ for (i = 0; i < ODEBUG_POOL_SIZE; i++)
+ hlist_add_head(&obj_static_pool[i].node, &obj_pool);
+}
+
+/*
+ * Called after the kmem_caches are functional to setup a dedicated
+ * cache pool, which has the SLAB_DEBUG_OBJECTS flag set. This flag
+ * prevents that the debug code is called on kmem_cache_free() for the
+ * debug tracker objects to avoid recursive calls.
+ */
+void __init debug_objects_mem_init(void)
+{
+ if (!debug_objects_enabled)
+ return;
+
+ obj_cache = kmem_cache_create("debug_objects_cache",
+ sizeof (struct debug_obj), 0,
+ SLAB_DEBUG_OBJECTS, NULL);
+
+ if (!obj_cache)
+ debug_objects_enabled = 0;
+ else
+ debug_objects_selftest();
+}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 0a502e9..bdd5c43 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -45,6 +45,7 @@
#include <linux/fault-inject.h>
#include <linux/page-isolation.h>
#include <linux/memcontrol.h>
+#include <linux/debugobjects.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -532,8 +533,11 @@ static void __free_pages_ok(struct page *page, unsigned int order)
if (reserved)
return;
- if (!PageHighMem(page))
+ if (!PageHighMem(page)) {
debug_check_no_locks_freed(page_address(page),PAGE_SIZE<<order);
+ debug_check_no_obj_freed(page_address(page),
+ PAGE_SIZE << order);
+ }
arch_free_page(page, order);
kernel_map_pages(page, 1 << order, 0);
@@ -995,8 +999,10 @@ static void free_hot_cold_page(struct page *page, int cold)
if (free_pages_check(page))
return;
- if (!PageHighMem(page))
+ if (!PageHighMem(page)) {
debug_check_no_locks_freed(page_address(page), PAGE_SIZE);
+ debug_check_no_obj_freed(page_address(page), PAGE_SIZE);
+ }
arch_free_page(page, 0);
kernel_map_pages(page, 1, 0);
diff --git a/mm/slab.c b/mm/slab.c
index 39d20f8..919a995 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -110,6 +110,7 @@
#include <linux/fault-inject.h>
#include <linux/rtmutex.h>
#include <linux/reciprocal_div.h>
+#include <linux/debugobjects.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@@ -174,12 +175,14 @@
SLAB_CACHE_DMA | \
SLAB_STORE_USER | \
SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
- SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
+ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
+ SLAB_DEBUG_OBJECTS)
#else
# define CREATE_MASK (SLAB_HWCACHE_ALIGN | \
SLAB_CACHE_DMA | \
SLAB_RECLAIM_ACCOUNT | SLAB_PANIC | \
- SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD)
+ SLAB_DESTROY_BY_RCU | SLAB_MEM_SPREAD | \
+ SLAB_DEBUG_OBJECTS)
#endif
/*
@@ -3760,6 +3763,8 @@ void kmem_cache_free(struct kmem_cache *cachep, void *objp)
local_irq_save(flags);
debug_check_no_locks_freed(objp, obj_size(cachep));
+ if (!(cachep->flags & SLAB_DEBUG_OBJECTS))
+ debug_check_no_obj_freed(objp, obj_size(cachep));
__cache_free(cachep, objp);
local_irq_restore(flags);
}
@@ -3785,6 +3790,7 @@ void kfree(const void *objp)
kfree_debugcheck(objp);
c = virt_to_cache(objp);
debug_check_no_locks_freed(objp, obj_size(c));
+ debug_check_no_obj_freed(objp, obj_size(c));
__cache_free(c, (void *)objp);
local_irq_restore(flags);
}
diff --git a/mm/slub.c b/mm/slub.c
index b145e79..70db289 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -19,6 +19,7 @@
#include <linux/cpuset.h>
#include <linux/mempolicy.h>
#include <linux/ctype.h>
+#include <linux/debugobjects.h>
#include <linux/kallsyms.h>
#include <linux/memory.h>
@@ -1747,6 +1748,8 @@ static __always_inline void slab_free(struct kmem_cache *s,
local_irq_save(flags);
c = get_cpu_slab(s, smp_processor_id());
debug_check_no_locks_freed(object, c->objsize);
+ if (!(s->flags & SLAB_DEBUG_OBJECTS))
+ debug_check_no_obj_freed(object, s->objsize);
if (likely(page == c->page && c->node >= 0)) {
object[c->offset] = c->freelist;
c->freelist = object;
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index e33e0ae..2a39cf1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -15,6 +15,7 @@
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
+#include <linux/debugobjects.h>
#include <linux/vmalloc.h>
#include <linux/kallsyms.h>
@@ -394,6 +395,7 @@ static void __vunmap(const void *addr, int deallocate_pages)
}
debug_check_no_locks_freed(addr, area->size);
+ debug_check_no_obj_freed(addr, area->size);
if (deallocate_pages) {
int i;