forked from luck/tmp_suning_uos_patched
c817a67ecb
Implement debugging for kobject release functions. kobjects are reference counted, so the drop of the last reference to them is not predictable. However, the common case is for the last reference to be the kobject's removal from a subsystem, which results in the release function being immediately called. This can hide subtle bugs, which can occur when another thread holds a reference to the kobject at the same time that a kobject is removed. This results in the release method being delayed. In order to make these kinds of problems more visible, the following patch implements a delayed release; this has the effect that the release function will be out of order with respect to the removal of the kobject in the same manner that it would be if a reference was being held. This provides us with an easy way to allow driver writers to debug their drivers and fix otherwise hidden problems. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
221 lines
6.6 KiB
C
221 lines
6.6 KiB
C
/*
|
|
* kobject.h - generic kernel object infrastructure.
|
|
*
|
|
* Copyright (c) 2002-2003 Patrick Mochel
|
|
* Copyright (c) 2002-2003 Open Source Development Labs
|
|
* Copyright (c) 2006-2008 Greg Kroah-Hartman <greg@kroah.com>
|
|
* Copyright (c) 2006-2008 Novell Inc.
|
|
*
|
|
* This file is released under the GPLv2.
|
|
*
|
|
* Please read Documentation/kobject.txt before using the kobject
|
|
* interface, ESPECIALLY the parts about reference counts and object
|
|
* destructors.
|
|
*/
|
|
|
|
#ifndef _KOBJECT_H_
|
|
#define _KOBJECT_H_
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/list.h>
|
|
#include <linux/sysfs.h>
|
|
#include <linux/compiler.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/kref.h>
|
|
#include <linux/kobject_ns.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/atomic.h>
|
|
#include <linux/workqueue.h>
|
|
|
|
#define UEVENT_HELPER_PATH_LEN 256
|
|
#define UEVENT_NUM_ENVP 32 /* number of env pointers */
|
|
#define UEVENT_BUFFER_SIZE 2048 /* buffer for the variables */
|
|
|
|
/* path to the userspace helper executed on an event */
|
|
extern char uevent_helper[];
|
|
|
|
/* counter to tag the uevent, read only except for the kobject core */
|
|
extern u64 uevent_seqnum;
|
|
|
|
/*
|
|
* The actions here must match the index to the string array
|
|
* in lib/kobject_uevent.c
|
|
*
|
|
* Do not add new actions here without checking with the driver-core
|
|
* maintainers. Action strings are not meant to express subsystem
|
|
* or device specific properties. In most cases you want to send a
|
|
* kobject_uevent_env(kobj, KOBJ_CHANGE, env) with additional event
|
|
* specific variables added to the event environment.
|
|
*/
|
|
enum kobject_action {
|
|
KOBJ_ADD,
|
|
KOBJ_REMOVE,
|
|
KOBJ_CHANGE,
|
|
KOBJ_MOVE,
|
|
KOBJ_ONLINE,
|
|
KOBJ_OFFLINE,
|
|
KOBJ_MAX
|
|
};
|
|
|
|
struct kobject {
|
|
const char *name;
|
|
struct list_head entry;
|
|
struct kobject *parent;
|
|
struct kset *kset;
|
|
struct kobj_type *ktype;
|
|
struct sysfs_dirent *sd;
|
|
struct kref kref;
|
|
#ifdef CONFIG_DEBUG_KOBJECT_RELEASE
|
|
struct delayed_work release;
|
|
#endif
|
|
unsigned int state_initialized:1;
|
|
unsigned int state_in_sysfs:1;
|
|
unsigned int state_add_uevent_sent:1;
|
|
unsigned int state_remove_uevent_sent:1;
|
|
unsigned int uevent_suppress:1;
|
|
};
|
|
|
|
extern __printf(2, 3)
|
|
int kobject_set_name(struct kobject *kobj, const char *name, ...);
|
|
extern int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
|
|
va_list vargs);
|
|
|
|
static inline const char *kobject_name(const struct kobject *kobj)
|
|
{
|
|
return kobj->name;
|
|
}
|
|
|
|
extern void kobject_init(struct kobject *kobj, struct kobj_type *ktype);
|
|
extern __printf(3, 4) __must_check
|
|
int kobject_add(struct kobject *kobj, struct kobject *parent,
|
|
const char *fmt, ...);
|
|
extern __printf(4, 5) __must_check
|
|
int kobject_init_and_add(struct kobject *kobj,
|
|
struct kobj_type *ktype, struct kobject *parent,
|
|
const char *fmt, ...);
|
|
|
|
extern void kobject_del(struct kobject *kobj);
|
|
|
|
extern struct kobject * __must_check kobject_create(void);
|
|
extern struct kobject * __must_check kobject_create_and_add(const char *name,
|
|
struct kobject *parent);
|
|
|
|
extern int __must_check kobject_rename(struct kobject *, const char *new_name);
|
|
extern int __must_check kobject_move(struct kobject *, struct kobject *);
|
|
|
|
extern struct kobject *kobject_get(struct kobject *kobj);
|
|
extern void kobject_put(struct kobject *kobj);
|
|
|
|
extern char *kobject_get_path(struct kobject *kobj, gfp_t flag);
|
|
|
|
struct kobj_type {
|
|
void (*release)(struct kobject *kobj);
|
|
const struct sysfs_ops *sysfs_ops;
|
|
struct attribute **default_attrs;
|
|
const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
|
|
const void *(*namespace)(struct kobject *kobj);
|
|
};
|
|
|
|
struct kobj_uevent_env {
|
|
char *envp[UEVENT_NUM_ENVP];
|
|
int envp_idx;
|
|
char buf[UEVENT_BUFFER_SIZE];
|
|
int buflen;
|
|
};
|
|
|
|
struct kset_uevent_ops {
|
|
int (* const filter)(struct kset *kset, struct kobject *kobj);
|
|
const char *(* const name)(struct kset *kset, struct kobject *kobj);
|
|
int (* const uevent)(struct kset *kset, struct kobject *kobj,
|
|
struct kobj_uevent_env *env);
|
|
};
|
|
|
|
struct kobj_attribute {
|
|
struct attribute attr;
|
|
ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,
|
|
char *buf);
|
|
ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *attr,
|
|
const char *buf, size_t count);
|
|
};
|
|
|
|
extern const struct sysfs_ops kobj_sysfs_ops;
|
|
|
|
struct sock;
|
|
|
|
/**
|
|
* struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.
|
|
*
|
|
* A kset defines a group of kobjects. They can be individually
|
|
* different "types" but overall these kobjects all want to be grouped
|
|
* together and operated on in the same manner. ksets are used to
|
|
* define the attribute callbacks and other common events that happen to
|
|
* a kobject.
|
|
*
|
|
* @list: the list of all kobjects for this kset
|
|
* @list_lock: a lock for iterating over the kobjects
|
|
* @kobj: the embedded kobject for this kset (recursion, isn't it fun...)
|
|
* @uevent_ops: the set of uevent operations for this kset. These are
|
|
* called whenever a kobject has something happen to it so that the kset
|
|
* can add new environment variables, or filter out the uevents if so
|
|
* desired.
|
|
*/
|
|
struct kset {
|
|
struct list_head list;
|
|
spinlock_t list_lock;
|
|
struct kobject kobj;
|
|
const struct kset_uevent_ops *uevent_ops;
|
|
};
|
|
|
|
extern void kset_init(struct kset *kset);
|
|
extern int __must_check kset_register(struct kset *kset);
|
|
extern void kset_unregister(struct kset *kset);
|
|
extern struct kset * __must_check kset_create_and_add(const char *name,
|
|
const struct kset_uevent_ops *u,
|
|
struct kobject *parent_kobj);
|
|
|
|
static inline struct kset *to_kset(struct kobject *kobj)
|
|
{
|
|
return kobj ? container_of(kobj, struct kset, kobj) : NULL;
|
|
}
|
|
|
|
static inline struct kset *kset_get(struct kset *k)
|
|
{
|
|
return k ? to_kset(kobject_get(&k->kobj)) : NULL;
|
|
}
|
|
|
|
static inline void kset_put(struct kset *k)
|
|
{
|
|
kobject_put(&k->kobj);
|
|
}
|
|
|
|
static inline struct kobj_type *get_ktype(struct kobject *kobj)
|
|
{
|
|
return kobj->ktype;
|
|
}
|
|
|
|
extern struct kobject *kset_find_obj(struct kset *, const char *);
|
|
|
|
/* The global /sys/kernel/ kobject for people to chain off of */
|
|
extern struct kobject *kernel_kobj;
|
|
/* The global /sys/kernel/mm/ kobject for people to chain off of */
|
|
extern struct kobject *mm_kobj;
|
|
/* The global /sys/hypervisor/ kobject for people to chain off of */
|
|
extern struct kobject *hypervisor_kobj;
|
|
/* The global /sys/power/ kobject for people to chain off of */
|
|
extern struct kobject *power_kobj;
|
|
/* The global /sys/firmware/ kobject for people to chain off of */
|
|
extern struct kobject *firmware_kobj;
|
|
|
|
int kobject_uevent(struct kobject *kobj, enum kobject_action action);
|
|
int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
|
|
char *envp[]);
|
|
|
|
__printf(2, 3)
|
|
int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...);
|
|
|
|
int kobject_action_type(const char *buf, size_t count,
|
|
enum kobject_action *type);
|
|
|
|
#endif /* _KOBJECT_H_ */
|