@ -56,9 +56,6 @@ struct user_struct root_user = {
. sigpending = ATOMIC_INIT ( 0 ) ,
. locked_shm = 0 ,
. user_ns = & init_user_ns ,
# ifdef CONFIG_USER_SCHED
. tg = & init_task_group ,
# endif
} ;
/*
@ -75,268 +72,6 @@ static void uid_hash_remove(struct user_struct *up)
put_user_ns ( up - > user_ns ) ;
}
# ifdef CONFIG_USER_SCHED
static void sched_destroy_user ( struct user_struct * up )
{
sched_destroy_group ( up - > tg ) ;
}
static int sched_create_user ( struct user_struct * up )
{
int rc = 0 ;
up - > tg = sched_create_group ( & root_task_group ) ;
if ( IS_ERR ( up - > tg ) )
rc = - ENOMEM ;
set_tg_uid ( up ) ;
return rc ;
}
# else /* CONFIG_USER_SCHED */
static void sched_destroy_user ( struct user_struct * up ) { }
static int sched_create_user ( struct user_struct * up ) { return 0 ; }
# endif /* CONFIG_USER_SCHED */
# if defined(CONFIG_USER_SCHED) && defined(CONFIG_SYSFS)
static struct user_struct * uid_hash_find ( uid_t uid , struct hlist_head * hashent )
{
struct user_struct * user ;
struct hlist_node * h ;
hlist_for_each_entry ( user , h , hashent , uidhash_node ) {
if ( user - > uid = = uid ) {
/* possibly resurrect an "almost deleted" object */
if ( atomic_inc_return ( & user - > __count ) = = 1 )
cancel_delayed_work ( & user - > work ) ;
return user ;
}
}
return NULL ;
}
static struct kset * uids_kset ; /* represents the /sys/kernel/uids/ directory */
static DEFINE_MUTEX ( uids_mutex ) ;
static inline void uids_mutex_lock ( void )
{
mutex_lock ( & uids_mutex ) ;
}
static inline void uids_mutex_unlock ( void )
{
mutex_unlock ( & uids_mutex ) ;
}
/* uid directory attributes */
# ifdef CONFIG_FAIR_GROUP_SCHED
static ssize_t cpu_shares_show ( struct kobject * kobj ,
struct kobj_attribute * attr ,
char * buf )
{
struct user_struct * up = container_of ( kobj , struct user_struct , kobj ) ;
return sprintf ( buf , " %lu \n " , sched_group_shares ( up - > tg ) ) ;
}
static ssize_t cpu_shares_store ( struct kobject * kobj ,
struct kobj_attribute * attr ,
const char * buf , size_t size )
{
struct user_struct * up = container_of ( kobj , struct user_struct , kobj ) ;
unsigned long shares ;
int rc ;
sscanf ( buf , " %lu " , & shares ) ;
rc = sched_group_set_shares ( up - > tg , shares ) ;
return ( rc ? rc : size ) ;
}
static struct kobj_attribute cpu_share_attr =
__ATTR ( cpu_share , 0644 , cpu_shares_show , cpu_shares_store ) ;
# endif
# ifdef CONFIG_RT_GROUP_SCHED
static ssize_t cpu_rt_runtime_show ( struct kobject * kobj ,
struct kobj_attribute * attr ,
char * buf )
{
struct user_struct * up = container_of ( kobj , struct user_struct , kobj ) ;
return sprintf ( buf , " %ld \n " , sched_group_rt_runtime ( up - > tg ) ) ;
}
static ssize_t cpu_rt_runtime_store ( struct kobject * kobj ,
struct kobj_attribute * attr ,
const char * buf , size_t size )
{
struct user_struct * up = container_of ( kobj , struct user_struct , kobj ) ;
unsigned long rt_runtime ;
int rc ;
sscanf ( buf , " %ld " , & rt_runtime ) ;
rc = sched_group_set_rt_runtime ( up - > tg , rt_runtime ) ;
return ( rc ? rc : size ) ;
}
static struct kobj_attribute cpu_rt_runtime_attr =
__ATTR ( cpu_rt_runtime , 0644 , cpu_rt_runtime_show , cpu_rt_runtime_store ) ;
static ssize_t cpu_rt_period_show ( struct kobject * kobj ,
struct kobj_attribute * attr ,
char * buf )
{
struct user_struct * up = container_of ( kobj , struct user_struct , kobj ) ;
return sprintf ( buf , " %lu \n " , sched_group_rt_period ( up - > tg ) ) ;
}
static ssize_t cpu_rt_period_store ( struct kobject * kobj ,
struct kobj_attribute * attr ,
const char * buf , size_t size )
{
struct user_struct * up = container_of ( kobj , struct user_struct , kobj ) ;
unsigned long rt_period ;
int rc ;
sscanf ( buf , " %lu " , & rt_period ) ;
rc = sched_group_set_rt_period ( up - > tg , rt_period ) ;
return ( rc ? rc : size ) ;
}
static struct kobj_attribute cpu_rt_period_attr =
__ATTR ( cpu_rt_period , 0644 , cpu_rt_period_show , cpu_rt_period_store ) ;
# endif
/* default attributes per uid directory */
static struct attribute * uids_attributes [ ] = {
# ifdef CONFIG_FAIR_GROUP_SCHED
& cpu_share_attr . attr ,
# endif
# ifdef CONFIG_RT_GROUP_SCHED
& cpu_rt_runtime_attr . attr ,
& cpu_rt_period_attr . attr ,
# endif
NULL
} ;
/* the lifetime of user_struct is not managed by the core (now) */
static void uids_release ( struct kobject * kobj )
{
return ;
}
static struct kobj_type uids_ktype = {
. sysfs_ops = & kobj_sysfs_ops ,
. default_attrs = uids_attributes ,
. release = uids_release ,
} ;
/*
* Create / sys / kernel / uids / < uid > / cpu_share file for this user
* We do not create this file for users in a user namespace ( until
* sysfs tagging is implemented ) .
*
* See Documentation / scheduler / sched - design - CFS . txt for ramifications .
*/
static int uids_user_create ( struct user_struct * up )
{
struct kobject * kobj = & up - > kobj ;
int error ;
memset ( kobj , 0 , sizeof ( struct kobject ) ) ;
if ( up - > user_ns ! = & init_user_ns )
return 0 ;
kobj - > kset = uids_kset ;
error = kobject_init_and_add ( kobj , & uids_ktype , NULL , " %d " , up - > uid ) ;
if ( error ) {
kobject_put ( kobj ) ;
goto done ;
}
kobject_uevent ( kobj , KOBJ_ADD ) ;
done :
return error ;
}
/* create these entries in sysfs:
* " /sys/kernel/uids " directory
* " /sys/kernel/uids/0 " directory ( for root user )
* " /sys/kernel/uids/0/cpu_share " file ( for root user )
*/
int __init uids_sysfs_init ( void )
{
uids_kset = kset_create_and_add ( " uids " , NULL , kernel_kobj ) ;
if ( ! uids_kset )
return - ENOMEM ;
return uids_user_create ( & root_user ) ;
}
/* delayed work function to remove sysfs directory for a user and free up
* corresponding structures .
*/
static void cleanup_user_struct ( struct work_struct * w )
{
struct user_struct * up = container_of ( w , struct user_struct , work . work ) ;
unsigned long flags ;
int remove_user = 0 ;
/* Make uid_hash_remove() + sysfs_remove_file() + kobject_del()
* atomic .
*/
uids_mutex_lock ( ) ;
spin_lock_irqsave ( & uidhash_lock , flags ) ;
if ( atomic_read ( & up - > __count ) = = 0 ) {
uid_hash_remove ( up ) ;
remove_user = 1 ;
}
spin_unlock_irqrestore ( & uidhash_lock , flags ) ;
if ( ! remove_user )
goto done ;
if ( up - > user_ns = = & init_user_ns ) {
kobject_uevent ( & up - > kobj , KOBJ_REMOVE ) ;
kobject_del ( & up - > kobj ) ;
kobject_put ( & up - > kobj ) ;
}
sched_destroy_user ( up ) ;
key_put ( up - > uid_keyring ) ;
key_put ( up - > session_keyring ) ;
kmem_cache_free ( uid_cachep , up ) ;
done :
uids_mutex_unlock ( ) ;
}
/* IRQs are disabled and uidhash_lock is held upon function entry.
* IRQ state ( as stored in flags ) is restored and uidhash_lock released
* upon function exit .
*/
static void free_user ( struct user_struct * up , unsigned long flags )
{
INIT_DELAYED_WORK ( & up - > work , cleanup_user_struct ) ;
schedule_delayed_work ( & up - > work , msecs_to_jiffies ( 1000 ) ) ;
spin_unlock_irqrestore ( & uidhash_lock , flags ) ;
}
# else /* CONFIG_USER_SCHED && CONFIG_SYSFS */
static struct user_struct * uid_hash_find ( uid_t uid , struct hlist_head * hashent )
{
struct user_struct * user ;
@ -352,11 +87,6 @@ static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
return NULL ;
}
int uids_sysfs_init ( void ) { return 0 ; }
static inline int uids_user_create ( struct user_struct * up ) { return 0 ; }
static inline void uids_mutex_lock ( void ) { }
static inline void uids_mutex_unlock ( void ) { }
/* IRQs are disabled and uidhash_lock is held upon function entry.
* IRQ state ( as stored in flags ) is restored and uidhash_lock released
* upon function exit .
@ -365,32 +95,11 @@ static void free_user(struct user_struct *up, unsigned long flags)
{
uid_hash_remove ( up ) ;
spin_unlock_irqrestore ( & uidhash_lock , flags ) ;
sched_destroy_user ( up ) ;
key_put ( up - > uid_keyring ) ;
key_put ( up - > session_keyring ) ;
kmem_cache_free ( uid_cachep , up ) ;
}
# endif
# if defined(CONFIG_RT_GROUP_SCHED) && defined(CONFIG_USER_SCHED)
/*
* We need to check if a setuid can take place . This function should be called
* before successfully completing the setuid .
*/
int task_can_switch_user ( struct user_struct * up , struct task_struct * tsk )
{
return sched_rt_can_attach ( up - > tg , tsk ) ;
}
# else
int task_can_switch_user ( struct user_struct * up , struct task_struct * tsk )
{
return 1 ;
}
# endif
/*
* Locate the user_struct for the passed UID . If found , take a ref on it . The
* caller must undo that ref with free_uid ( ) .
@ -431,8 +140,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
/* Make uid_hash_find() + uids_user_create() + uid_hash_insert()
* atomic .
*/
uids_mutex_lock ( ) ;
spin_lock_irq ( & uidhash_lock ) ;
up = uid_hash_find ( uid , hashent ) ;
spin_unlock_irq ( & uidhash_lock ) ;
@ -445,14 +152,8 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
new - > uid = uid ;
atomic_set ( & new - > __count , 1 ) ;
if ( sched_create_user ( new ) < 0 )
goto out_free_user ;
new - > user_ns = get_user_ns ( ns ) ;
if ( uids_user_create ( new ) )
goto out_destoy_sched ;
/*
* Before adding this , check whether we raced
* on adding the same user already . .
@ -475,17 +176,11 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
spin_unlock_irq ( & uidhash_lock ) ;
}
uids_mutex_unlock ( ) ;
return up ;
out_destoy_sched :
sched_destroy_user ( new ) ;
put_user_ns ( new - > user_ns ) ;
out_free_user :
kmem_cache_free ( uid_cachep , new ) ;
out_unlock :
uids_mutex_unlock ( ) ;
return NULL ;
}
Dhaval Giani
15 years ago
committed by