X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fmutex-debug.c;h=841539d72c55cdbb674b7a91786847c37ec5acdb;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=f4913c3769505a10a0bfd169b6e2ad5c0f25f48c;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c
index f4913c376..841539d72 100644
--- a/kernel/mutex-debug.c
+++ b/kernel/mutex-debug.c
@@ -16,395 +16,48 @@
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/module.h>
+#include <linux/poison.h>
 #include <linux/spinlock.h>
 #include <linux/kallsyms.h>
 #include <linux/interrupt.h>
+#include <linux/debug_locks.h>
 
 #include "mutex-debug.h"
 
-/*
- * We need a global lock when we walk through the multi-process
- * lock tree. Only used in the deadlock-debugging case.
- */
-DEFINE_SPINLOCK(debug_mutex_lock);
-
-/*
- * All locks held by all tasks, in a single global list:
- */
-LIST_HEAD(debug_mutex_held_locks);
-
-/*
- * In the debug case we carry the caller's instruction pointer into
- * other functions, but we dont want the function argument overhead
- * in the nondebug case - hence these macros:
- */
-#define __IP_DECL__		, unsigned long ip
-#define __IP__			, ip
-#define __RET_IP__		, (unsigned long)__builtin_return_address(0)
-
-/*
- * "mutex debugging enabled" flag. We turn it off when we detect
- * the first problem because we dont want to recurse back
- * into the tracing code when doing error printk or
- * executing a BUG():
- */
-int debug_mutex_on = 1;
-
-static void printk_task(struct task_struct *p)
-{
-	if (p)
-		printk("%16s:%5d [%p, %3d]", p->comm, p->pid, p, p->prio);
-	else
-		printk("<none>");
-}
-
-static void printk_ti(struct thread_info *ti)
-{
-	if (ti)
-		printk_task(ti->task);
-	else
-		printk("<none>");
-}
-
-static void printk_task_short(struct task_struct *p)
-{
-	if (p)
-		printk("%s/%d [%p, %3d]", p->comm, p->pid, p, p->prio);
-	else
-		printk("<none>");
-}
-
-static void printk_lock(struct mutex *lock, int print_owner)
-{
-	printk(" [%p] {%s}\n", lock, lock->name);
-
-	if (print_owner && lock->owner) {
-		printk(".. held by:  ");
-		printk_ti(lock->owner);
-		printk("\n");
-	}
-	if (lock->owner) {
-		printk("... acquired at:               ");
-		print_symbol("%s\n", lock->acquire_ip);
-	}
-}
-
-/*
- * printk locks held by a task:
- */
-static void show_task_locks(struct task_struct *p)
-{
-	switch (p->state) {
-	case TASK_RUNNING:		printk("R"); break;
-	case TASK_INTERRUPTIBLE:	printk("S"); break;
-	case TASK_UNINTERRUPTIBLE:	printk("D"); break;
-	case TASK_STOPPED:		printk("T"); break;
-	case EXIT_ZOMBIE:		printk("Z"); break;
-	case EXIT_DEAD:			printk("X"); break;
-	default:			printk("?"); break;
-	}
-	printk_task(p);
-	if (p->blocked_on) {
-		struct mutex *lock = p->blocked_on->lock;
-
-		printk(" blocked on mutex:");
-		printk_lock(lock, 1);
-	} else
-		printk(" (not blocked on mutex)\n");
-}
-
-/*
- * printk all locks held in the system (if filter == NULL),
- * or all locks belonging to a single task (if filter != NULL):
- */
-void show_held_locks(struct task_struct *filter)
-{
-	struct list_head *curr, *cursor = NULL;
-	struct mutex *lock;
-	struct thread_info *t;
-	unsigned long flags;
-	int count = 0;
-
-	if (filter) {
-		printk("------------------------------\n");
-		printk("| showing all locks held by: |  (");
-		printk_task_short(filter);
-		printk("):\n");
-		printk("------------------------------\n");
-	} else {
-		printk("---------------------------\n");
-		printk("| showing all locks held: |\n");
-		printk("---------------------------\n");
-	}
-
-	/*
-	 * Play safe and acquire the global trace lock. We
-	 * cannot printk with that lock held so we iterate
-	 * very carefully:
-	 */
-next:
-	debug_spin_lock_save(&debug_mutex_lock, flags);
-	list_for_each(curr, &debug_mutex_held_locks) {
-		if (cursor && curr != cursor)
-			continue;
-		lock = list_entry(curr, struct mutex, held_list);
-		t = lock->owner;
-		if (filter && (t != filter->thread_info))
-			continue;
-		count++;
-		cursor = curr->next;
-		debug_spin_lock_restore(&debug_mutex_lock, flags);
-
-		printk("\n#%03d:            ", count);
-		printk_lock(lock, filter ? 0 : 1);
-		goto next;
-	}
-	debug_spin_lock_restore(&debug_mutex_lock, flags);
-	printk("\n");
-}
-
-void mutex_debug_show_all_locks(void)
-{
-	struct task_struct *g, *p;
-	int count = 10;
-	int unlock = 1;
-
-	printk("\nShowing all blocking locks in the system:\n");
-
-	/*
-	 * Here we try to get the tasklist_lock as hard as possible,
-	 * if not successful after 2 seconds we ignore it (but keep
-	 * trying). This is to enable a debug printout even if a
-	 * tasklist_lock-holding task deadlocks or crashes.
-	 */
-retry:
-	if (!read_trylock(&tasklist_lock)) {
-		if (count == 10)
-			printk("hm, tasklist_lock locked, retrying... ");
-		if (count) {
-			count--;
-			printk(" #%d", 10-count);
-			mdelay(200);
-			goto retry;
-		}
-		printk(" ignoring it.\n");
-		unlock = 0;
-	}
-	if (count != 10)
-		printk(" locked it.\n");
-
-	do_each_thread(g, p) {
-		show_task_locks(p);
-		if (!unlock)
-			if (read_trylock(&tasklist_lock))
-				unlock = 1;
-	} while_each_thread(g, p);
-
-	printk("\n");
-	show_held_locks(NULL);
-	printk("=============================================\n\n");
-
-	if (unlock)
-		read_unlock(&tasklist_lock);
-}
-
-static void report_deadlock(struct task_struct *task, struct mutex *lock,
-			    struct mutex *lockblk, unsigned long ip)
-{
-	printk("\n%s/%d is trying to acquire this lock:\n",
-		current->comm, current->pid);
-	printk_lock(lock, 1);
-	printk("... trying at:                 ");
-	print_symbol("%s\n", ip);
-	show_held_locks(current);
-
-	if (lockblk) {
-		printk("but %s/%d is deadlocking current task %s/%d!\n\n",
-			task->comm, task->pid, current->comm, current->pid);
-		printk("\n%s/%d is blocked on this lock:\n",
-			task->comm, task->pid);
-		printk_lock(lockblk, 1);
-
-		show_held_locks(task);
-
-		printk("\n%s/%d's [blocked] stackdump:\n\n",
-			task->comm, task->pid);
-		show_stack(task, NULL);
-	}
-
-	printk("\n%s/%d's [current] stackdump:\n\n",
-		current->comm, current->pid);
-	dump_stack();
-	mutex_debug_show_all_locks();
-	printk("[ turning off deadlock detection. Please report this. ]\n\n");
-	local_irq_disable();
-}
-
-/*
- * Recursively check for mutex deadlocks:
- */
-static int check_deadlock(struct mutex *lock, int depth,
-			  struct thread_info *ti, unsigned long ip)
-{
-	struct mutex *lockblk;
-	struct task_struct *task;
-
-	if (!debug_mutex_on)
-		return 0;
-
-	ti = lock->owner;
-	if (!ti)
-		return 0;
-
-	task = ti->task;
-	lockblk = NULL;
-	if (task->blocked_on)
-		lockblk = task->blocked_on->lock;
-
-	/* Self-deadlock: */
-	if (current == task) {
-		DEBUG_OFF();
-		if (depth)
-			return 1;
-		printk("\n==========================================\n");
-		printk(  "[ BUG: lock recursion deadlock detected! |\n");
-		printk(  "------------------------------------------\n");
-		report_deadlock(task, lock, NULL, ip);
-		return 0;
-	}
-
-	/* Ugh, something corrupted the lock data structure? */
-	if (depth > 20) {
-		DEBUG_OFF();
-		printk("\n===========================================\n");
-		printk(  "[ BUG: infinite lock dependency detected!? |\n");
-		printk(  "-------------------------------------------\n");
-		report_deadlock(task, lock, lockblk, ip);
-		return 0;
-	}
-
-	/* Recursively check for dependencies: */
-	if (lockblk && check_deadlock(lockblk, depth+1, ti, ip)) {
-		printk("\n============================================\n");
-		printk(  "[ BUG: circular locking deadlock detected! ]\n");
-		printk(  "--------------------------------------------\n");
-		report_deadlock(task, lock, lockblk, ip);
-		return 0;
-	}
-	return 0;
-}
-
-/*
- * Called when a task exits, this function checks whether the
- * task is holding any locks, and reports the first one if so:
- */
-void mutex_debug_check_no_locks_held(struct task_struct *task)
-{
-	struct list_head *curr, *next;
-	struct thread_info *t;
-	unsigned long flags;
-	struct mutex *lock;
-
-	if (!debug_mutex_on)
-		return;
-
-	debug_spin_lock_save(&debug_mutex_lock, flags);
-	list_for_each_safe(curr, next, &debug_mutex_held_locks) {
-		lock = list_entry(curr, struct mutex, held_list);
-		t = lock->owner;
-		if (t != task->thread_info)
-			continue;
-		list_del_init(curr);
-		DEBUG_OFF();
-		debug_spin_lock_restore(&debug_mutex_lock, flags);
-
-		printk("BUG: %s/%d, lock held at task exit time!\n",
-			task->comm, task->pid);
-		printk_lock(lock, 1);
-		if (lock->owner != task->thread_info)
-			printk("exiting task is not even the owner??\n");
-		return;
-	}
-	debug_spin_lock_restore(&debug_mutex_lock, flags);
-}
-
-/*
- * Called when kernel memory is freed (or unmapped), or if a mutex
- * is destroyed or reinitialized - this code checks whether there is
- * any held lock in the memory range of <from> to <to>:
- */
-void mutex_debug_check_no_locks_freed(const void *from, unsigned long len)
-{
-	struct list_head *curr, *next;
-	const void *to = from + len;
-	unsigned long flags;
-	struct mutex *lock;
-	void *lock_addr;
-
-	if (!debug_mutex_on)
-		return;
-
-	debug_spin_lock_save(&debug_mutex_lock, flags);
-	list_for_each_safe(curr, next, &debug_mutex_held_locks) {
-		lock = list_entry(curr, struct mutex, held_list);
-		lock_addr = lock;
-		if (lock_addr < from || lock_addr >= to)
-			continue;
-		list_del_init(curr);
-		DEBUG_OFF();
-		debug_spin_lock_restore(&debug_mutex_lock, flags);
-
-		printk("BUG: %s/%d, active lock [%p(%p-%p)] freed!\n",
-			current->comm, current->pid, lock, from, to);
-		dump_stack();
-		printk_lock(lock, 1);
-		if (lock->owner != current_thread_info())
-			printk("freeing task is not even the owner??\n");
-		return;
-	}
-	debug_spin_lock_restore(&debug_mutex_lock, flags);
-}
-
 /*
  * Must be called with lock->wait_lock held.
  */
-void debug_mutex_set_owner(struct mutex *lock,
-			   struct thread_info *new_owner __IP_DECL__)
+void debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner)
 {
 	lock->owner = new_owner;
-	DEBUG_WARN_ON(!list_empty(&lock->held_list));
-	if (debug_mutex_on) {
-		list_add_tail(&lock->held_list, &debug_mutex_held_locks);
-		lock->acquire_ip = ip;
-	}
 }
 
-void debug_mutex_init_waiter(struct mutex_waiter *waiter)
+void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
 {
-	memset(waiter, 0x11, sizeof(*waiter));
+	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
 	waiter->magic = waiter;
 	INIT_LIST_HEAD(&waiter->list);
 }
 
 void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
 {
-	SMP_DEBUG_WARN_ON(!spin_is_locked(&lock->wait_lock));
-	DEBUG_WARN_ON(list_empty(&lock->wait_list));
-	DEBUG_WARN_ON(waiter->magic != waiter);
-	DEBUG_WARN_ON(list_empty(&waiter->list));
+	SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
+	DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
+	DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
+	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
 }
 
 void debug_mutex_free_waiter(struct mutex_waiter *waiter)
 {
-	DEBUG_WARN_ON(!list_empty(&waiter->list));
-	memset(waiter, 0x22, sizeof(*waiter));
+	DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
+	memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
 }
 
 void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
-			    struct thread_info *ti __IP_DECL__)
+			    struct thread_info *ti)
 {
-	SMP_DEBUG_WARN_ON(!spin_is_locked(&lock->wait_lock));
-	check_deadlock(lock, 0, ti, ip);
+	SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
+
 	/* Mark the current thread as blocked on the lock: */
 	ti->task->blocked_on = waiter;
 	waiter->lock = lock;
@@ -413,9 +66,9 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 			 struct thread_info *ti)
 {
-	DEBUG_WARN_ON(list_empty(&waiter->list));
-	DEBUG_WARN_ON(waiter->task != ti->task);
-	DEBUG_WARN_ON(ti->task->blocked_on != waiter);
+	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
+	DEBUG_LOCKS_WARN_ON(waiter->task != ti->task);
+	DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter);
 	ti->task->blocked_on = NULL;
 
 	list_del_init(&waiter->list);
@@ -424,24 +77,26 @@ void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
 
 void debug_mutex_unlock(struct mutex *lock)
 {
-	DEBUG_WARN_ON(lock->magic != lock);
-	DEBUG_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
-	DEBUG_WARN_ON(lock->owner != current_thread_info());
-	if (debug_mutex_on) {
-		DEBUG_WARN_ON(list_empty(&lock->held_list));
-		list_del_init(&lock->held_list);
-	}
+	if (unlikely(!debug_locks))
+		return;
+
+	DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
+	DEBUG_LOCKS_WARN_ON(lock->magic != lock);
+	DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
+	DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
 }
 
-void debug_mutex_init(struct mutex *lock, const char *name)
+void debug_mutex_init(struct mutex *lock, const char *name,
+		      struct lock_class_key *key)
 {
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
 	/*
 	 * Make sure we are not reinitializing a held lock:
 	 */
-	mutex_debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+	lockdep_init_map(&lock->dep_map, name, key, 0);
+#endif
 	lock->owner = NULL;
-	INIT_LIST_HEAD(&lock->held_list);
-	lock->name = name;
 	lock->magic = lock;
 }
 
@@ -455,7 +110,7 @@ void debug_mutex_init(struct mutex *lock, const char *name)
  */
 void fastcall mutex_destroy(struct mutex *lock)
 {
-	DEBUG_WARN_ON(mutex_is_locked(lock));
+	DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
 	lock->magic = NULL;
 }