Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (46 commits)
  UIO: Fix mapping of logical and virtual memory
  UIO: add automata sercos3 pci card support
  UIO: Change driver name of uio_pdrv
  UIO: Add alignment warnings for uio-mem
  Driver core: add bus_sort_breadthfirst() function
  NET: convert the phy_device file to use bus_find_device_by_name
  kobject: Cleanup kobject_rename and !CONFIG_SYSFS
  kobject: Fix kobject_rename and !CONFIG_SYSFS
  sysfs: Make dir and name args to sysfs_notify() const
  platform: add new device registration helper
  sysfs: use ilookup5() instead of ilookup5_nowait()
  PNP: create device attributes via default device attributes
  Driver core: make bus_find_device_by_name() more robust
  usb: turn dev_warn+WARN_ON combos into dev_WARN
  debug: use dev_WARN() rather than WARN_ON() in device_pm_add()
  debug: Introduce a dev_WARN() function
  sysfs: fix deadlock
  device model: Do a quickcheck for driver binding before doing an expensive check
  Driver core: Fix cleanup in device_create_vargs().
  Driver core: Clarify device cleanup.
  ...

lib/Kconfig.debug

@@ -807,6 +807,61 @@ menuconfig BUILD_DOCSRC
 
 	  Say N if you are unsure.
 
+config DYNAMIC_PRINTK_DEBUG
+	bool "Enable dynamic printk() call support"
+	default n
+	depends on PRINTK
+	select PRINTK_DEBUG
+	help
+
+	  Compiles debug level messages into the kernel, which would not
+	  otherwise be available at runtime. These messages can then be
+	  enabled/disabled on a per module basis. This mechanism implicitly
+	  enables all pr_debug() and dev_dbg() calls. The impact of this
+	  compile option is a larger kernel text size of about 2%.
+
+	  Usage:
+
+	  Dynamic debugging is controlled by the debugfs file,
+	  dynamic_printk/modules. This file contains a list of the modules that
+	  can be enabled. The format of the file is the module name, followed
+	  by a set of flags that can be enabled. The first flag is always the
+	  'enabled' flag. For example:
+
+		<module_name> <enabled=0/1>
+				.
+				.
+				.
+
+	  <module_name> : Name of the module in which the debug call resides
+	  <enabled=0/1> : whether the messages are enabled or not
+
+	  From a live system:
+
+		snd_hda_intel enabled=0
+		fixup enabled=0
+		driver enabled=0
+
+	  Enable a module:
+
+	  	$echo "set enabled=1 <module_name>" > dynamic_printk/modules
+
+	  Disable a module:
+
+	  	$echo "set enabled=0 <module_name>" > dynamic_printk/modules
+
+	  Enable all modules:
+
+		$echo "set enabled=1 all" > dynamic_printk/modules
+
+	  Disable all modules:
+
+		$echo "set enabled=0 all" > dynamic_printk/modules
+
+	  Finally, passing "dynamic_printk" at the command line enables
+	  debugging for all modules. This mode can be turned off via the above
+	  disable command.
+
 source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"

lib/Makefile

@@ -81,6 +81,8 @@ obj-$(CONFIG_HAVE_LMB) += lmb.o
 
 obj-$(CONFIG_HAVE_ARCH_TRACEHOOK) += syscall.o
 
+obj-$(CONFIG_DYNAMIC_PRINTK_DEBUG) += dynamic_printk.o
+
 hostprogs-y	:= gen_crc32table
 clean-files	:= crc32table.h
 

lib/dynamic_printk.c

@@ -0,0 +1,418 @@
+/*
+ * lib/dynamic_printk.c
+ *
+ * make pr_debug()/dev_dbg() calls runtime configurable based upon their
+ * their source module.
+ *
+ * Copyright (C) 2008 Red Hat, Inc., Jason Baron <jbaron@redhat.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/fs.h>
+
+extern struct mod_debug __start___verbose[];
+extern struct mod_debug __stop___verbose[];
+
+struct debug_name {
+	struct hlist_node hlist;
+	struct hlist_node hlist2;
+	int hash1;
+	int hash2;
+	char *name;
+	int enable;
+	int type;
+};
+
+static int nr_entries;
+static int num_enabled;
+int dynamic_enabled = DYNAMIC_ENABLED_NONE;
+static struct hlist_head module_table[DEBUG_HASH_TABLE_SIZE] =
+	{ [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT };
+static struct hlist_head module_table2[DEBUG_HASH_TABLE_SIZE] =
+	{ [0 ... DEBUG_HASH_TABLE_SIZE-1] = HLIST_HEAD_INIT };
+static DECLARE_MUTEX(debug_list_mutex);
+
+/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
+ * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
+ * use independent hash functions, to reduce the chance of false positives.
+ */
+long long dynamic_printk_enabled;
+EXPORT_SYMBOL_GPL(dynamic_printk_enabled);
+long long dynamic_printk_enabled2;
+EXPORT_SYMBOL_GPL(dynamic_printk_enabled2);
+
+/* returns the debug module pointer. */
+static struct debug_name *find_debug_module(char *module_name)
+{
+	int i;
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct debug_name *element;
+
+	element = NULL;
+	for (i = 0; i < DEBUG_HASH_TABLE_SIZE; i++) {
+		head = &module_table[i];
+		hlist_for_each_entry_rcu(element, node, head, hlist)
+			if (!strcmp(element->name, module_name))
+				return element;
+	}
+	return NULL;
+}
+
+/* returns the debug module pointer. */
+static struct debug_name *find_debug_module_hash(char *module_name, int hash)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct debug_name *element;
+
+	element = NULL;
+	head = &module_table[hash];
+	hlist_for_each_entry_rcu(element, node, head, hlist)
+		if (!strcmp(element->name, module_name))
+			return element;
+	return NULL;
+}
+
+/* caller must hold mutex*/
+static int __add_debug_module(char *mod_name, int hash, int hash2)
+{
+	struct debug_name *new;
+	char *module_name;
+	int ret = 0;
+
+	if (find_debug_module(mod_name)) {
+		ret = -EINVAL;
+		goto out;
+	}
+	module_name = kmalloc(strlen(mod_name) + 1, GFP_KERNEL);
+	if (!module_name) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	module_name = strcpy(module_name, mod_name);
+	module_name[strlen(mod_name)] = '\0';
+	new = kzalloc(sizeof(struct debug_name), GFP_KERNEL);
+	if (!new) {
+		kfree(module_name);
+		ret = -ENOMEM;
+		goto out;
+	}
+	INIT_HLIST_NODE(&new->hlist);
+	INIT_HLIST_NODE(&new->hlist2);
+	new->name = module_name;
+	new->hash1 = hash;
+	new->hash2 = hash2;
+	hlist_add_head_rcu(&new->hlist, &module_table[hash]);
+	hlist_add_head_rcu(&new->hlist2, &module_table2[hash2]);
+	nr_entries++;
+out:
+	return ret;
+}
+
+int unregister_dynamic_debug_module(char *mod_name)
+{
+	struct debug_name *element;
+	int ret = 0;
+
+	down(&debug_list_mutex);
+	element = find_debug_module(mod_name);
+	if (!element) {
+		ret = -EINVAL;
+		goto out;
+	}
+	hlist_del_rcu(&element->hlist);
+	hlist_del_rcu(&element->hlist2);
+	synchronize_rcu();
+	kfree(element->name);
+	if (element->enable)
+		num_enabled--;
+	kfree(element);
+	nr_entries--;
+out:
+	up(&debug_list_mutex);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(unregister_dynamic_debug_module);
+
+int register_dynamic_debug_module(char *mod_name, int type, char *share_name,
+					char *flags, int hash, int hash2)
+{
+	struct debug_name *elem;
+	int ret = 0;
+
+	down(&debug_list_mutex);
+	elem = find_debug_module(mod_name);
+	if (!elem) {
+		if (__add_debug_module(mod_name, hash, hash2))
+			goto out;
+		elem = find_debug_module(mod_name);
+		if (dynamic_enabled == DYNAMIC_ENABLED_ALL &&
+				!strcmp(mod_name, share_name)) {
+			elem->enable = true;
+			num_enabled++;
+		}
+	}
+	elem->type |= type;
+out:
+	up(&debug_list_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(register_dynamic_debug_module);
+
+int __dynamic_dbg_enabled_helper(char *mod_name, int type, int value, int hash)
+{
+	struct debug_name *elem;
+	int ret = 0;
+
+	if (dynamic_enabled == DYNAMIC_ENABLED_ALL)
+		return 1;
+	rcu_read_lock();
+	elem = find_debug_module_hash(mod_name, hash);
+	if (elem && elem->enable)
+		ret = 1;
+	rcu_read_unlock();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__dynamic_dbg_enabled_helper);
+
+static void set_all(bool enable)
+{
+	struct debug_name *e;
+	struct hlist_node *node;
+	int i;
+	long long enable_mask;
+
+	for (i = 0; i < DEBUG_HASH_TABLE_SIZE; i++) {
+		if (module_table[i].first != NULL) {
+			hlist_for_each_entry(e, node, &module_table[i], hlist) {
+				e->enable = enable;
+			}
+		}
+	}
+	if (enable)
+		enable_mask = ULLONG_MAX;
+	else
+		enable_mask = 0;
+	dynamic_printk_enabled = enable_mask;
+	dynamic_printk_enabled2 = enable_mask;
+}
+
+static int disabled_hash(int i, bool first_table)
+{
+	struct debug_name *e;
+	struct hlist_node *node;
+
+	if (first_table) {
+		hlist_for_each_entry(e, node, &module_table[i], hlist) {
+			if (e->enable)
+				return 0;
+		}
+	} else {
+		hlist_for_each_entry(e, node, &module_table2[i], hlist2) {
+			if (e->enable)
+				return 0;
+		}
+	}
+	return 1;
+}
+
+static ssize_t pr_debug_write(struct file *file, const char __user *buf,
+				size_t length, loff_t *ppos)
+{
+	char *buffer, *s, *value_str, *setting_str;
+	int err, value;
+	struct debug_name *elem = NULL;
+	int all = 0;
+
+	if (length > PAGE_SIZE || length < 0)
+		return -EINVAL;
+
+	buffer = (char *)__get_free_page(GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
+	err = -EFAULT;
+	if (copy_from_user(buffer, buf, length))
+		goto out;
+
+	err = -EINVAL;
+	if (length < PAGE_SIZE)
+		buffer[length] = '\0';
+	else if (buffer[PAGE_SIZE-1])
+		goto out;
+
+	err = -EINVAL;
+	down(&debug_list_mutex);
+
+	if (strncmp("set", buffer, 3))
+		goto out_up;
+	s = buffer + 3;
+	setting_str = strsep(&s, "=");
+	if (s == NULL)
+		goto out_up;
+	setting_str = strstrip(setting_str);
+	value_str = strsep(&s, " ");
+	if (s == NULL)
+		goto out_up;
+	s = strstrip(s);
+	if (!strncmp(s, "all", 3))
+		all = 1;
+	else
+		elem = find_debug_module(s);
+	if (!strncmp(setting_str, "enable", 6)) {
+		value = !!simple_strtol(value_str, NULL, 10);
+		if (all) {
+			if (value) {
+				set_all(true);
+				num_enabled = nr_entries;
+				dynamic_enabled = DYNAMIC_ENABLED_ALL;
+			} else {
+				set_all(false);
+				num_enabled = 0;
+				dynamic_enabled = DYNAMIC_ENABLED_NONE;
+			}
+			err = 0;
+		} else {
+			if (elem) {
+				if (value && (elem->enable == 0)) {
+					dynamic_printk_enabled |=
+							(1LL << elem->hash1);
+					dynamic_printk_enabled2 |=
+							(1LL << elem->hash2);
+					elem->enable = 1;
+					num_enabled++;
+					dynamic_enabled = DYNAMIC_ENABLED_SOME;
+					err = 0;
+					printk(KERN_DEBUG
+					       "debugging enabled for module %s",
+					       elem->name);
+				} else if (!value && (elem->enable == 1)) {
+					elem->enable = 0;
+					num_enabled--;
+					if (disabled_hash(elem->hash1, true))
+						dynamic_printk_enabled &=
+							~(1LL << elem->hash1);
+					if (disabled_hash(elem->hash2, false))
+						dynamic_printk_enabled2 &=
+							~(1LL << elem->hash2);
+					if (num_enabled)
+						dynamic_enabled =
+							DYNAMIC_ENABLED_SOME;
+					else
+						dynamic_enabled =
+							DYNAMIC_ENABLED_NONE;
+					err = 0;
+					printk(KERN_DEBUG
+					       "debugging disabled for module "
+					       "%s", elem->name);
+				}
+			}
+		}
+	}
+	if (!err)
+		err = length;
+out_up:
+	up(&debug_list_mutex);
+out:
+	free_page((unsigned long)buffer);
+	return err;
+}
+
+static void *pr_debug_seq_start(struct seq_file *f, loff_t *pos)
+{
+	return (*pos < DEBUG_HASH_TABLE_SIZE) ? pos : NULL;
+}
+
+static void *pr_debug_seq_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	(*pos)++;
+	if (*pos >= DEBUG_HASH_TABLE_SIZE)
+		return NULL;
+	return pos;
+}
+
+static void pr_debug_seq_stop(struct seq_file *s, void *v)
+{
+	/* Nothing to do */
+}
+
+static int pr_debug_seq_show(struct seq_file *s, void *v)
+{
+	struct hlist_head *head;
+	struct hlist_node *node;
+	struct debug_name *elem;
+	unsigned int i = *(loff_t *) v;
+
+	rcu_read_lock();
+	head = &module_table[i];
+	hlist_for_each_entry_rcu(elem, node, head, hlist) {
+		seq_printf(s, "%s enabled=%d", elem->name, elem->enable);
+		seq_printf(s, "\n");
+	}
+	rcu_read_unlock();
+	return 0;
+}
+
+static struct seq_operations pr_debug_seq_ops = {
+	.start = pr_debug_seq_start,
+	.next  = pr_debug_seq_next,
+	.stop  = pr_debug_seq_stop,
+	.show  = pr_debug_seq_show
+};
+
+static int pr_debug_open(struct inode *inode, struct file *filp)
+{
+	return seq_open(filp, &pr_debug_seq_ops);
+}
+
+static const struct file_operations pr_debug_operations = {
+	.open		= pr_debug_open,
+	.read		= seq_read,
+	.write		= pr_debug_write,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int __init dynamic_printk_init(void)
+{
+	struct dentry *dir, *file;
+	struct mod_debug *iter;
+	unsigned long value;
+
+	dir = debugfs_create_dir("dynamic_printk", NULL);
+	if (!dir)
+		return -ENOMEM;
+	file = debugfs_create_file("modules", 0644, dir, NULL,
+					&pr_debug_operations);
+	if (!file) {
+		debugfs_remove(dir);
+		return -ENOMEM;
+	}
+	for (value = (unsigned long)__start___verbose;
+		value < (unsigned long)__stop___verbose;
+		value += sizeof(struct mod_debug)) {
+			iter = (struct mod_debug *)value;
+			register_dynamic_debug_module(iter->modname,
+				iter->type,
+				iter->logical_modname,
+				iter->flag_names, iter->hash, iter->hash2);
+	}
+	return 0;
+}
+module_init(dynamic_printk_init);
+/* may want to move this earlier so we can get traces as early as possible */
+
+static int __init dynamic_printk_setup(char *str)
+{
+	if (str)
+		return -ENOENT;
+	set_all(true);
+	return 0;
+}
+/* Use early_param(), so we can get debug output as early as possible */
+early_param("dynamic_printk", dynamic_printk_setup);

lib/kobject.c

@@ -387,11 +387,17 @@ EXPORT_SYMBOL_GPL(kobject_init_and_add);
  * kobject_rename - change the name of an object
  * @kobj: object in question.
  * @new_name: object's new name
+ *
+ * It is the responsibility of the caller to provide mutual
+ * exclusion between two different calls of kobject_rename
+ * on the same kobject and to ensure that new_name is valid and
+ * won't conflict with other kobjects.
  */
 int kobject_rename(struct kobject *kobj, const char *new_name)
 {
 	int error = 0;
 	const char *devpath = NULL;
+	const char *dup_name = NULL, *name;
 	char *devpath_string = NULL;
 	char *envp[2];
 
@@ -401,19 +407,6 @@ int kobject_rename(struct kobject *kobj, const char *new_name)
 	if (!kobj->parent)
 		return -EINVAL;
 
-	/* see if this name is already in use */
-	if (kobj->kset) {
-		struct kobject *temp_kobj;
-		temp_kobj = kset_find_obj(kobj->kset, new_name);
-		if (temp_kobj) {
-			printk(KERN_WARNING "kobject '%s' cannot be renamed "
-			       "to '%s' as '%s' is already in existence.\n",
-			       kobject_name(kobj), new_name, new_name);
-			kobject_put(temp_kobj);
-			return -EINVAL;
-		}
-	}
-
 	devpath = kobject_get_path(kobj, GFP_KERNEL);
 	if (!devpath) {
 		error = -ENOMEM;
@@ -428,15 +421,27 @@ int kobject_rename(struct kobject *kobj, const char *new_name)
 	envp[0] = devpath_string;
 	envp[1] = NULL;
 
+	name = dup_name = kstrdup(new_name, GFP_KERNEL);
+	if (!name) {
+		error = -ENOMEM;
+		goto out;
+	}
+
 	error = sysfs_rename_dir(kobj, new_name);
+	if (error)
+		goto out;
+
+	/* Install the new kobject name */
+	dup_name = kobj->name;
+	kobj->name = name;
 
 	/* This function is mostly/only used for network interface.
 	 * Some hotplug package track interfaces by their name and
 	 * therefore want to know when the name is changed by the user. */
-	if (!error)
-		kobject_uevent_env(kobj, KOBJ_MOVE, envp);
+	kobject_uevent_env(kobj, KOBJ_MOVE, envp);
 
 out:
+	kfree(dup_name);
 	kfree(devpath_string);
 	kfree(devpath);
 	kobject_put(kobj);