Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Branch: jellybean
Fetching contributors…

Cannot retrieve contributors at this time

1050 lines (890 sloc) 25.777 kB
/*
* 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/sched.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/slab.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;
raw_spinlock_t lock;
};
static struct debug_bucket obj_hash[ODEBUG_HASH_SIZE];
static struct debug_obj obj_static_pool[ODEBUG_POOL_SIZE] __initdata;
static DEFINE_RAW_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
= CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT;
static struct debug_obj_descr *descr_test __read_mostly;
static void free_obj_work(struct work_struct *work);
static DECLARE_WORK(debug_obj_work, free_obj_work);
static int __init enable_object_debug(char *str)
{
debug_objects_enabled = 1;
return 0;
}
static int __init disable_object_debug(char *str)
{
debug_objects_enabled = 0;
return 0;
}
early_param("debug_objects", enable_object_debug);
early_param("no_debug_objects", disable_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;
unsigned long flags;
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;
raw_spin_lock_irqsave(&pool_lock, flags);
hlist_add_head(&new->node, &obj_pool);
obj_pool_free++;
raw_spin_unlock_irqrestore(&pool_lock, flags);
}
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, switch off the debugger.
* Must be called with interrupts disabled.
*/
static struct debug_obj *
alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
{
struct debug_obj *obj = NULL;
raw_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;
obj->astate = 0;
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;
}
raw_spin_unlock(&pool_lock);
return obj;
}
/*
* workqueue function to free objects.
*/
static void free_obj_work(struct work_struct *work)
{
struct debug_obj *obj;
unsigned long flags;
raw_spin_lock_irqsave(&pool_lock, flags);
while (obj_pool_free > ODEBUG_POOL_SIZE) {
obj = hlist_entry(obj_pool.first, typeof(*obj), node);
hlist_del(&obj->node);
obj_pool_free--;
/*
* We release pool_lock across kmem_cache_free() to
* avoid contention on pool_lock.
*/
raw_spin_unlock_irqrestore(&pool_lock, flags);
kmem_cache_free(obj_cache, obj);
raw_spin_lock_irqsave(&pool_lock, flags);
}
raw_spin_unlock_irqrestore(&pool_lock, flags);
}
/*
* Put the object back into the pool and schedule work to free objects
* if necessary.
*/
static void free_object(struct debug_obj *obj)
{
unsigned long flags;
int sched = 0;
raw_spin_lock_irqsave(&pool_lock, flags);
/*
* schedule work when the pool is filled and the cache is
* initialized:
*/
if (obj_pool_free > ODEBUG_POOL_SIZE && obj_cache)
sched = !work_pending(&debug_obj_work);
hlist_add_head(&obj->node, &obj_pool);
obj_pool_free++;
obj_pool_used--;
raw_spin_unlock_irqrestore(&pool_lock, flags);
if (sched)
schedule_work(&debug_obj_work);
}
/*
* 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;
HLIST_HEAD(freelist);
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++) {
raw_spin_lock_irqsave(&db->lock, flags);
hlist_move_list(&db->list, &freelist);
raw_spin_unlock_irqrestore(&db->lock, flags);
/* Now free them */
hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
hlist_del(&obj->node);
free_object(obj);
}
}
}
/*
* 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++;
WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
"object type: %s\n",
msg, obj_states[obj->state], obj->astate,
obj->descr->name);
}
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)
{
int is_on_stack;
static int limit;
if (limit > 4)
return;
is_on_stack = object_is_on_stack(addr);
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;
fill_pool();
db = get_bucket((unsigned long) addr);
raw_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;
raw_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;
raw_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;
}
raw_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);
raw_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;
raw_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;
}
raw_spin_unlock_irqrestore(&db->lock, flags);
return;
}
raw_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);
raw_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:
if (!obj->astate)
obj->state = ODEBUG_STATE_INACTIVE;
else
debug_print_object(obj, "deactivate");
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");
}
raw_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);
raw_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;
raw_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:
raw_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);
raw_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;
raw_spin_unlock_irqrestore(&db->lock, flags);
debug_object_fixup(descr->fixup_free, addr, state);
return;
default:
hlist_del(&obj->node);
raw_spin_unlock_irqrestore(&db->lock, flags);
free_object(obj);
return;
}
out_unlock:
raw_spin_unlock_irqrestore(&db->lock, flags);
}
/**
* debug_object_active_state - debug checks object usage state machine
* @addr: address of the object
* @descr: pointer to an object specific debug description structure
* @expect: expected state
* @next: state to move to if expected state is found
*/
void
debug_object_active_state(void *addr, struct debug_obj_descr *descr,
unsigned int expect, unsigned int next)
{
struct debug_bucket *db;
struct debug_obj *obj;
unsigned long flags;
if (!debug_objects_enabled)
return;
db = get_bucket((unsigned long) addr);
raw_spin_lock_irqsave(&db->lock, flags);
obj = lookup_object(addr, db);
if (obj) {
switch (obj->state) {
case ODEBUG_STATE_ACTIVE:
if (obj->astate == expect)
obj->astate = next;
else
debug_print_object(obj, "active_state");
break;
default:
debug_print_object(obj, "active_state");
break;
}
} else {
struct debug_obj o = { .object = addr,
.state = ODEBUG_STATE_NOTAVAILABLE,
.descr = descr };
debug_print_object(&o, "active_state");
}
raw_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;
HLIST_HEAD(freelist);
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;
raw_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;
raw_spin_unlock_irqrestore(&db->lock, flags);
debug_object_fixup(descr->fixup_free,
(void *) oaddr, state);
goto repeat;
default:
hlist_del(&obj->node);
hlist_add_head(&obj->node, &freelist);
break;
}
}
raw_spin_unlock_irqrestore(&db->lock, flags);
/* Now free them */
hlist_for_each_entry_safe(obj, node, tmp, &freelist, node) {
hlist_del(&obj->node);
free_object(obj);
}
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 __init
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);
raw_spin_lock_irqsave(&db->lock, flags);
obj = lookup_object(addr, db);
if (!obj && state != ODEBUG_STATE_NONE) {
WARN(1, KERN_ERR "ODEBUG: selftest object not found\n");
goto out;
}
if (obj && obj->state != state) {
WARN(1, KERN_ERR "ODEBUG: selftest wrong state: %d != %d\n",
obj->state, state);
goto out;
}
if (fixups != debug_objects_fixups) {
WARN(1, KERN_ERR "ODEBUG: selftest fixups failed %d != %d\n",
fixups, debug_objects_fixups);
goto out;
}
if (warnings != debug_objects_warnings) {
WARN(1, KERN_ERR "ODEBUG: selftest warnings failed %d != %d\n",
warnings, debug_objects_warnings);
goto out;
}
res = 0;
out:
raw_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++)
raw_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);
}
/*
* Convert the statically allocated objects to dynamic ones:
*/
static int __init debug_objects_replace_static_objects(void)
{
struct debug_bucket *db = obj_hash;
struct hlist_node *node, *tmp;
struct debug_obj *obj, *new;
HLIST_HEAD(objects);
int i, cnt = 0;
for (i = 0; i < ODEBUG_POOL_SIZE; i++) {
obj = kmem_cache_zalloc(obj_cache, GFP_KERNEL);
if (!obj)
goto free;
hlist_add_head(&obj->node, &objects);
}
/*
* When debug_objects_mem_init() is called we know that only
* one CPU is up, so disabling interrupts is enough
* protection. This avoids the lockdep hell of lock ordering.
*/
local_irq_disable();
/* Remove the statically allocated objects from the pool */
hlist_for_each_entry_safe(obj, node, tmp, &obj_pool, node)
hlist_del(&obj->node);
/* Move the allocated objects to the pool */
hlist_move_list(&objects, &obj_pool);
/* Replace the active object references */
for (i = 0; i < ODEBUG_HASH_SIZE; i++, db++) {
hlist_move_list(&db->list, &objects);
hlist_for_each_entry(obj, node, &objects, node) {
new = hlist_entry(obj_pool.first, typeof(*obj), node);
hlist_del(&new->node);
/* copy object data */
*new = *obj;
hlist_add_head(&new->node, &db->list);
cnt++;
}
}
printk(KERN_DEBUG "ODEBUG: %d of %d active objects replaced\n", cnt,
obj_pool_used);
local_irq_enable();
return 0;
free:
hlist_for_each_entry_safe(obj, node, tmp, &objects, node) {
hlist_del(&obj->node);
kmem_cache_free(obj_cache, obj);
}
return -ENOMEM;
}
/*
* 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_replace_static_objects()) {
debug_objects_enabled = 0;
if (obj_cache)
kmem_cache_destroy(obj_cache);
printk(KERN_WARNING "ODEBUG: out of memory.\n");
} else
debug_objects_selftest();
}
Jump to Line
Something went wrong with that request. Please try again.