X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fuser.c;h=477b6660f447e639a8b181d456c7c4e64e30b008;hb=abfe2d7b915c872f3a1fd203267cedebf90daa45;hp=5a106f3fdf05f1c7239d3911de12618a77beff5b;hpb=eb41d9465cdafee45e0cb30f3b7338646221908e;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/user.c b/kernel/user.c index 5a106f3..477b666 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -16,6 +16,15 @@ #include #include #include +#include "cred-internals.h" + +struct user_namespace init_user_ns = { + .kref = { + .refcount = ATOMIC_INIT(1), + }, + .creator = &root_user, +}; +EXPORT_SYMBOL_GPL(init_user_ns); /* * UID task count cache, to get fast user lookup in "alloc_uid" @@ -39,17 +48,15 @@ static struct kmem_cache *uid_cachep; */ static DEFINE_SPINLOCK(uidhash_lock); +/* root_user.__count is 2, 1 for init task cred, 1 for init_user_ns->creator */ struct user_struct root_user = { - .__count = ATOMIC_INIT(1), + .__count = ATOMIC_INIT(2), .processes = ATOMIC_INIT(1), .files = ATOMIC_INIT(0), .sigpending = ATOMIC_INIT(0), .locked_shm = 0, -#ifdef CONFIG_KEYS - .uid_keyring = &root_user_keyring, - .session_keyring = &root_session_keyring, -#endif -#ifdef CONFIG_FAIR_USER_SCHED + .user_ns = &init_user_ns, +#ifdef CONFIG_USER_SCHED .tg = &init_task_group, #endif }; @@ -82,7 +89,7 @@ static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent) return NULL; } -#ifdef CONFIG_FAIR_USER_SCHED +#ifdef CONFIG_USER_SCHED static void sched_destroy_user(struct user_struct *up) { @@ -93,27 +100,23 @@ static int sched_create_user(struct user_struct *up) { int rc = 0; - up->tg = sched_create_group(); + up->tg = sched_create_group(&root_task_group); if (IS_ERR(up->tg)) rc = -ENOMEM; - return rc; -} + set_tg_uid(up); -static void sched_switch_user(struct task_struct *p) -{ - sched_move_task(p); + return rc; } -#else /* CONFIG_FAIR_USER_SCHED */ +#else /* CONFIG_USER_SCHED */ static void sched_destroy_user(struct user_struct *up) { } static int sched_create_user(struct user_struct *up) { return 0; } -static void sched_switch_user(struct task_struct *p) { } -#endif /* CONFIG_FAIR_USER_SCHED */ +#endif /* CONFIG_USER_SCHED */ -#if defined(CONFIG_FAIR_USER_SCHED) && defined(CONFIG_SYSFS) +#if defined(CONFIG_USER_SCHED) && defined(CONFIG_SYSFS) static struct kset *uids_kset; /* represents the /sys/kernel/uids/ directory */ static DEFINE_MUTEX(uids_mutex); @@ -129,6 +132,7 @@ static inline void uids_mutex_unlock(void) } /* uid directory attributes */ +#ifdef CONFIG_FAIR_GROUP_SCHED static ssize_t cpu_shares_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) @@ -155,10 +159,73 @@ static ssize_t cpu_shares_store(struct kobject *kobj, 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 }; @@ -174,20 +241,27 @@ static struct kobj_type uids_ktype = { .release = uids_release, }; -/* create /sys/kernel/uids//cpu_share file for this user */ +/* + * Create /sys/kernel/uids//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)); - kobj->ktype = &uids_ktype; + if (up->user_ns != &init_user_ns) + return 0; kobj->kset = uids_kset; - kobject_init(kobj); - kobject_set_name(&up->kobj, "%d", up->uid); - error = kobject_add(kobj); - if (error) + 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: @@ -201,7 +275,7 @@ done: */ int __init uids_sysfs_init(void) { - uids_kset = kset_create_and_add("uids", NULL, &kernel_kset->kobj); + uids_kset = kset_create_and_add("uids", NULL, kernel_kobj); if (!uids_kset) return -ENOMEM; @@ -217,6 +291,8 @@ static void remove_user_sysfs_dir(struct work_struct *w) unsigned long flags; int remove_user = 0; + if (up->user_ns != &init_user_ns) + return; /* Make uid_hash_remove() + sysfs_remove_file() + kobject_del() * atomic. */ @@ -252,17 +328,18 @@ done: * IRQ state (as stored in flags) is restored and uidhash_lock released * upon function exit. */ -static inline void free_user(struct user_struct *up, unsigned long flags) +static void free_user(struct user_struct *up, unsigned long flags) { /* restore back the count */ atomic_inc(&up->__count); spin_unlock_irqrestore(&uidhash_lock, flags); + put_user_ns(up->user_ns); INIT_WORK(&up->work, remove_user_sysfs_dir); schedule_work(&up->work); } -#else /* CONFIG_FAIR_USER_SCHED && CONFIG_SYSFS */ +#else /* CONFIG_USER_SCHED && CONFIG_SYSFS */ int uids_sysfs_init(void) { return 0; } static inline int uids_user_create(struct user_struct *up) { return 0; } @@ -273,13 +350,14 @@ static inline void uids_mutex_unlock(void) { } * IRQ state (as stored in flags) is restored and uidhash_lock released * upon function exit. */ -static inline void free_user(struct user_struct *up, unsigned long flags) +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); + put_user_ns(up->user_ns); kmem_cache_free(uid_cachep, up); } @@ -295,7 +373,7 @@ struct user_struct *find_user(uid_t uid) { struct user_struct *ret; unsigned long flags; - struct user_namespace *ns = current->nsproxy->user_ns; + struct user_namespace *ns = current_user_ns(); spin_lock_irqsave(&uidhash_lock, flags); ret = uid_hash_find(uid, uidhashentry(ns, uid)); @@ -317,10 +395,10 @@ void free_uid(struct user_struct *up) local_irq_restore(flags); } -struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) +struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) { struct hlist_head *hashent = uidhashentry(ns, uid); - struct user_struct *up; + struct user_struct *up, *new; /* Make uid_hash_find() + uids_user_create() + uid_hash_insert() * atomic. @@ -332,50 +410,20 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) spin_unlock_irq(&uidhash_lock); if (!up) { - struct user_struct *new; - - new = kmem_cache_alloc(uid_cachep, GFP_KERNEL); - if (!new) { - uids_mutex_unlock(); - return NULL; - } + new = kmem_cache_zalloc(uid_cachep, GFP_KERNEL); + if (!new) + goto out_unlock; new->uid = uid; atomic_set(&new->__count, 1); - atomic_set(&new->processes, 0); - atomic_set(&new->files, 0); - atomic_set(&new->sigpending, 0); -#ifdef CONFIG_INOTIFY_USER - atomic_set(&new->inotify_watches, 0); - atomic_set(&new->inotify_devs, 0); -#endif -#ifdef CONFIG_POSIX_MQUEUE - new->mq_bytes = 0; -#endif - new->locked_shm = 0; - if (alloc_uid_keyring(new, current) < 0) { - kmem_cache_free(uid_cachep, new); - uids_mutex_unlock(); - return NULL; - } + if (sched_create_user(new) < 0) + goto out_free_user; - if (sched_create_user(new) < 0) { - key_put(new->uid_keyring); - key_put(new->session_keyring); - kmem_cache_free(uid_cachep, new); - uids_mutex_unlock(); - return NULL; - } + new->user_ns = get_user_ns(ns); - if (uids_user_create(new)) { - sched_destroy_user(new); - key_put(new->uid_keyring); - key_put(new->session_keyring); - kmem_cache_free(uid_cachep, new); - uids_mutex_unlock(); - return NULL; - } + if (uids_user_create(new)) + goto out_destoy_sched; /* * Before adding this, check whether we raced @@ -384,7 +432,7 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) spin_lock_irq(&uidhash_lock); up = uid_hash_find(uid, hashent); if (up) { - /* This case is not possible when CONFIG_FAIR_USER_SCHED + /* This case is not possible when CONFIG_USER_SCHED * is defined, since we serialize alloc_uid() using * uids_mutex. Hence no need to call * sched_destroy_user() or remove_user_sysfs_dir(). @@ -397,67 +445,20 @@ struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid) up = new; } spin_unlock_irq(&uidhash_lock); - } uids_mutex_unlock(); return up; -} - -void switch_uid(struct user_struct *new_user) -{ - struct user_struct *old_user; - - /* What if a process setreuid()'s and this brings the - * new uid over his NPROC rlimit? We can check this now - * cheaply with the new uid cache, so if it matters - * we should be checking for it. -DaveM - */ - old_user = current->user; - atomic_inc(&new_user->processes); - atomic_dec(&old_user->processes); - switch_uid_keyring(new_user); - current->user = new_user; - sched_switch_user(current); - - /* - * We need to synchronize with __sigqueue_alloc() - * doing a get_uid(p->user).. If that saw the old - * user value, we need to wait until it has exited - * its critical region before we can free the old - * structure. - */ - smp_mb(); - spin_unlock_wait(¤t->sighand->siglock); - - free_uid(old_user); - suid_keys(current); -} - -void release_uids(struct user_namespace *ns) -{ - int i; - unsigned long flags; - struct hlist_head *head; - struct hlist_node *nd; - - spin_lock_irqsave(&uidhash_lock, flags); - /* - * collapse the chains so that the user_struct-s will - * be still alive, but not in hashes. subsequent free_uid() - * will free them. - */ - for (i = 0; i < UIDHASH_SZ; i++) { - head = ns->uidhash_table + i; - while (!hlist_empty(head)) { - nd = head->first; - hlist_del_init(nd); - } - } - spin_unlock_irqrestore(&uidhash_lock, flags); - free_uid(ns->root_user); +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; } static int __init uid_cache_init(void)