diff options
Diffstat (limited to 'kernel/lib/debugobjects.c')
| -rw-r--r-- | kernel/lib/debugobjects.c | 1100 |
1 files changed, 1100 insertions, 0 deletions
diff --git a/kernel/lib/debugobjects.c b/kernel/lib/debugobjects.c new file mode 100644 index 000000000..8fcdbc2fc --- /dev/null +++ b/kernel/lib/debugobjects.c @@ -0,0 +1,1100 @@ +/* + * 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 + */ + +#define pr_fmt(fmt) "ODEBUG: " fmt + +#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 void 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; + + if (unlikely(!obj_cache)) + return; + + while (obj_pool_free < ODEBUG_POOL_MIN_LEVEL) { + + new = kmem_cache_zalloc(obj_cache, gfp); + if (!new) + return; + + raw_spin_lock_irqsave(&pool_lock, flags); + hlist_add_head(&new->node, &obj_pool); + obj_pool_free++; + raw_spin_unlock_irqrestore(&pool_lock, flags); + } +} + +/* + * Lookup an object in the hash bucket. + */ +static struct debug_obj *lookup_object(void *addr, struct debug_bucket *b) +{ + struct debug_obj *obj; + int cnt = 0; + + hlist_for_each_entry(obj, &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 = keventd_up(); + 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 *tmp; + HLIST_HEAD(freelist); + struct debug_obj *obj; + unsigned long flags; + int i; + + pr_warn("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, 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) +{ + struct debug_obj_descr *descr = obj->descr; + static int limit; + + if (limit < 5 && descr != descr_test) { + void *hint = descr->debug_hint ? + descr->debug_hint(obj->object) : NULL; + limit++; + WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " + "object type: %s hint: %pS\n", + msg, obj_states[obj->state], obj->astate, + descr->name, hint); + } + debug_objects_warnings++; +} + +/* + * Try to repair the damage, so we have a better chance to get useful + * debug output. + */ +static int +debug_object_fixup(int (*fixup)(void *addr, enum debug_obj_state state), + void * addr, enum debug_obj_state state) +{ + int fixed = 0; + + if (fixup) + fixed = fixup(addr, state); + debug_objects_fixups += fixed; + return fixed; +} + +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) + pr_warn("object is on stack, but not annotated\n"); + else + pr_warn("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; + +#ifdef CONFIG_PREEMPT_RT_FULL + if (preempt_count() == 0 && !irqs_disabled()) +#endif + 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 + * Returns 0 for success, -EINVAL for check failed. + */ +int 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; + int ret; + struct debug_obj o = { .object = addr, + .state = ODEBUG_STATE_NOTAVAILABLE, + .descr = descr }; + + if (!debug_objects_enabled) + return 0; + + 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; + ret = 0; + break; + + case ODEBUG_STATE_ACTIVE: + debug_print_object(obj, "activate"); + state = obj->state; + raw_spin_unlock_irqrestore(&db->lock, flags); + ret = debug_object_fixup(descr->fixup_activate, addr, state); + return ret ? -EINVAL : 0; + + case ODEBUG_STATE_DESTROYED: + debug_print_object(obj, "activate"); + ret = -EINVAL; + break; + default: + ret = 0; + break; + } + raw_spin_unlock_irqrestore(&db->lock, flags); + return ret; + } + + 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. + */ + if (debug_object_fixup(descr->fixup_activate, addr, + ODEBUG_STATE_NOTAVAILABLE)) { + debug_print_object(&o, "activate"); + return -EINVAL; + } + return 0; +} + +/** + * 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_assert_init - debug checks when object should be init-ed + * @addr: address of the object + * @descr: pointer to an object specific debug description structure + */ +void debug_object_assert_init(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) { + struct debug_obj o = { .object = addr, + .state = ODEBUG_STATE_NOTAVAILABLE, + .descr = descr }; + + raw_spin_unlock_irqrestore(&db->lock, flags); + /* + * Maybe the object is static. Let the type specific + * code decide what to do. + */ + if (debug_object_fixup(descr->fixup_assert_init, addr, + ODEBUG_STATE_NOTAVAILABLE)) + debug_print_object(&o, "assert_init"); + return; + } + + 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 *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, 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, 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); + return 0; + } + return 1; + + 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 + pr_info("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 *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, 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, &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++; + } + } + local_irq_enable(); + + pr_debug("%d of %d active objects replaced\n", + cnt, obj_pool_used); + return 0; +free: + hlist_for_each_entry_safe(obj, 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); + pr_warn("out of memory.\n"); + } else + debug_objects_selftest(); +} |