Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * The "user cache". |
| 3 | * |
| 4 | * (C) Copyright 1991-2000 Linus Torvalds |
| 5 | * |
| 6 | * We have a per-user structure to keep track of how many |
| 7 | * processes, files etc the user has claimed, in order to be |
| 8 | * able to have per-user limits for system resources. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/bitops.h> |
| 15 | #include <linux/key.h> |
Ingo Molnar | 4021cb2 | 2006-01-25 15:23:07 +0100 | [diff] [blame] | 16 | #include <linux/interrupt.h> |
Cedric Le Goater | acce292 | 2007-07-15 23:40:59 -0700 | [diff] [blame] | 17 | #include <linux/module.h> |
| 18 | #include <linux/user_namespace.h> |
David Howells | d84f4f9 | 2008-11-14 10:39:23 +1100 | [diff] [blame] | 19 | #include "cred-internals.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
Pavel Emelyanov | aee16ce | 2008-02-08 04:18:23 -0800 | [diff] [blame] | 21 | struct user_namespace init_user_ns = { |
| 22 | .kref = { |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 23 | .refcount = ATOMIC_INIT(1), |
Pavel Emelyanov | aee16ce | 2008-02-08 04:18:23 -0800 | [diff] [blame] | 24 | }, |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 25 | .creator = &root_user, |
Pavel Emelyanov | aee16ce | 2008-02-08 04:18:23 -0800 | [diff] [blame] | 26 | }; |
| 27 | EXPORT_SYMBOL_GPL(init_user_ns); |
| 28 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | /* |
| 30 | * UID task count cache, to get fast user lookup in "alloc_uid" |
| 31 | * when changing user ID's (ie setuid() and friends). |
| 32 | */ |
| 33 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | #define UIDHASH_MASK (UIDHASH_SZ - 1) |
| 35 | #define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK) |
Cedric Le Goater | acce292 | 2007-07-15 23:40:59 -0700 | [diff] [blame] | 36 | #define uidhashentry(ns, uid) ((ns)->uidhash_table + __uidhashfn((uid))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 38 | static struct kmem_cache *uid_cachep; |
Ingo Molnar | 4021cb2 | 2006-01-25 15:23:07 +0100 | [diff] [blame] | 39 | |
| 40 | /* |
| 41 | * The uidhash_lock is mostly taken from process context, but it is |
| 42 | * occasionally also taken from softirq/tasklet context, when |
| 43 | * task-structs get RCU-freed. Hence all locking must be softirq-safe. |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 44 | * But free_uid() is also called with local interrupts disabled, and running |
| 45 | * local_bh_enable() with local interrupts disabled is an error - we'll run |
| 46 | * softirq callbacks, and they can unconditionally enable interrupts, and |
| 47 | * the caller of free_uid() didn't expect that.. |
Ingo Molnar | 4021cb2 | 2006-01-25 15:23:07 +0100 | [diff] [blame] | 48 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | static DEFINE_SPINLOCK(uidhash_lock); |
| 50 | |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 51 | /* root_user.__count is 2, 1 for init task cred, 1 for init_user_ns->creator */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | struct user_struct root_user = { |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 53 | .__count = ATOMIC_INIT(2), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | .processes = ATOMIC_INIT(1), |
| 55 | .files = ATOMIC_INIT(0), |
| 56 | .sigpending = ATOMIC_INIT(0), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | .locked_shm = 0, |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 58 | .user_ns = &init_user_ns, |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 59 | #ifdef CONFIG_USER_SCHED |
Ingo Molnar | 4cf86d7 | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 60 | .tg = &init_task_group, |
Srivatsa Vaddagiri | 24e377a | 2007-10-15 17:00:09 +0200 | [diff] [blame] | 61 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | }; |
| 63 | |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 64 | /* |
| 65 | * These routines must be called with the uidhash spinlock held! |
| 66 | */ |
Alexey Dobriyan | 40aeb40 | 2007-10-16 23:30:09 -0700 | [diff] [blame] | 67 | static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 68 | { |
| 69 | hlist_add_head(&up->uidhash_node, hashent); |
| 70 | } |
| 71 | |
Alexey Dobriyan | 40aeb40 | 2007-10-16 23:30:09 -0700 | [diff] [blame] | 72 | static void uid_hash_remove(struct user_struct *up) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 73 | { |
| 74 | hlist_del_init(&up->uidhash_node); |
| 75 | } |
| 76 | |
Alexey Dobriyan | 40aeb40 | 2007-10-16 23:30:09 -0700 | [diff] [blame] | 77 | static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 78 | { |
| 79 | struct user_struct *user; |
| 80 | struct hlist_node *h; |
| 81 | |
| 82 | hlist_for_each_entry(user, h, hashent, uidhash_node) { |
| 83 | if (user->uid == uid) { |
| 84 | atomic_inc(&user->__count); |
| 85 | return user; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | return NULL; |
| 90 | } |
| 91 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 92 | #ifdef CONFIG_USER_SCHED |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 93 | |
Srivatsa Vaddagiri | 24e377a | 2007-10-15 17:00:09 +0200 | [diff] [blame] | 94 | static void sched_destroy_user(struct user_struct *up) |
| 95 | { |
| 96 | sched_destroy_group(up->tg); |
| 97 | } |
| 98 | |
| 99 | static int sched_create_user(struct user_struct *up) |
| 100 | { |
| 101 | int rc = 0; |
| 102 | |
Peter Zijlstra | eff766a | 2008-04-19 19:45:00 +0200 | [diff] [blame] | 103 | up->tg = sched_create_group(&root_task_group); |
Srivatsa Vaddagiri | 24e377a | 2007-10-15 17:00:09 +0200 | [diff] [blame] | 104 | if (IS_ERR(up->tg)) |
| 105 | rc = -ENOMEM; |
| 106 | |
| 107 | return rc; |
| 108 | } |
| 109 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 110 | #else /* CONFIG_USER_SCHED */ |
Dhaval Giani | b1a8c17 | 2007-10-17 16:55:11 +0200 | [diff] [blame] | 111 | |
| 112 | static void sched_destroy_user(struct user_struct *up) { } |
| 113 | static int sched_create_user(struct user_struct *up) { return 0; } |
Dhaval Giani | b1a8c17 | 2007-10-17 16:55:11 +0200 | [diff] [blame] | 114 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 115 | #endif /* CONFIG_USER_SCHED */ |
Dhaval Giani | b1a8c17 | 2007-10-17 16:55:11 +0200 | [diff] [blame] | 116 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 117 | #if defined(CONFIG_USER_SCHED) && defined(CONFIG_SYSFS) |
Dhaval Giani | b1a8c17 | 2007-10-17 16:55:11 +0200 | [diff] [blame] | 118 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 119 | static struct kset *uids_kset; /* represents the /sys/kernel/uids/ directory */ |
Dhaval Giani | b1a8c17 | 2007-10-17 16:55:11 +0200 | [diff] [blame] | 120 | static DEFINE_MUTEX(uids_mutex); |
| 121 | |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 122 | static inline void uids_mutex_lock(void) |
| 123 | { |
| 124 | mutex_lock(&uids_mutex); |
| 125 | } |
| 126 | |
| 127 | static inline void uids_mutex_unlock(void) |
| 128 | { |
| 129 | mutex_unlock(&uids_mutex); |
| 130 | } |
| 131 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 132 | /* uid directory attributes */ |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 133 | #ifdef CONFIG_FAIR_GROUP_SCHED |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 134 | static ssize_t cpu_shares_show(struct kobject *kobj, |
| 135 | struct kobj_attribute *attr, |
| 136 | char *buf) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 137 | { |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 138 | struct user_struct *up = container_of(kobj, struct user_struct, kobj); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 139 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 140 | return sprintf(buf, "%lu\n", sched_group_shares(up->tg)); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 141 | } |
| 142 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 143 | static ssize_t cpu_shares_store(struct kobject *kobj, |
| 144 | struct kobj_attribute *attr, |
| 145 | const char *buf, size_t size) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 146 | { |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 147 | struct user_struct *up = container_of(kobj, struct user_struct, kobj); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 148 | unsigned long shares; |
| 149 | int rc; |
| 150 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 151 | sscanf(buf, "%lu", &shares); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 152 | |
| 153 | rc = sched_group_set_shares(up->tg, shares); |
| 154 | |
| 155 | return (rc ? rc : size); |
| 156 | } |
| 157 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 158 | static struct kobj_attribute cpu_share_attr = |
| 159 | __ATTR(cpu_share, 0644, cpu_shares_show, cpu_shares_store); |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 160 | #endif |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 161 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 162 | #ifdef CONFIG_RT_GROUP_SCHED |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 163 | static ssize_t cpu_rt_runtime_show(struct kobject *kobj, |
| 164 | struct kobj_attribute *attr, |
| 165 | char *buf) |
| 166 | { |
| 167 | struct user_struct *up = container_of(kobj, struct user_struct, kobj); |
| 168 | |
Peter Zijlstra | af4491e | 2008-08-19 12:33:02 +0200 | [diff] [blame] | 169 | return sprintf(buf, "%ld\n", sched_group_rt_runtime(up->tg)); |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 170 | } |
| 171 | |
| 172 | static ssize_t cpu_rt_runtime_store(struct kobject *kobj, |
| 173 | struct kobj_attribute *attr, |
| 174 | const char *buf, size_t size) |
| 175 | { |
| 176 | struct user_struct *up = container_of(kobj, struct user_struct, kobj); |
| 177 | unsigned long rt_runtime; |
| 178 | int rc; |
| 179 | |
Peter Zijlstra | af4491e | 2008-08-19 12:33:02 +0200 | [diff] [blame] | 180 | sscanf(buf, "%ld", &rt_runtime); |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 181 | |
| 182 | rc = sched_group_set_rt_runtime(up->tg, rt_runtime); |
| 183 | |
| 184 | return (rc ? rc : size); |
| 185 | } |
| 186 | |
| 187 | static struct kobj_attribute cpu_rt_runtime_attr = |
| 188 | __ATTR(cpu_rt_runtime, 0644, cpu_rt_runtime_show, cpu_rt_runtime_store); |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 189 | |
| 190 | static ssize_t cpu_rt_period_show(struct kobject *kobj, |
| 191 | struct kobj_attribute *attr, |
| 192 | char *buf) |
| 193 | { |
| 194 | struct user_struct *up = container_of(kobj, struct user_struct, kobj); |
| 195 | |
| 196 | return sprintf(buf, "%lu\n", sched_group_rt_period(up->tg)); |
| 197 | } |
| 198 | |
| 199 | static ssize_t cpu_rt_period_store(struct kobject *kobj, |
| 200 | struct kobj_attribute *attr, |
| 201 | const char *buf, size_t size) |
| 202 | { |
| 203 | struct user_struct *up = container_of(kobj, struct user_struct, kobj); |
| 204 | unsigned long rt_period; |
| 205 | int rc; |
| 206 | |
| 207 | sscanf(buf, "%lu", &rt_period); |
| 208 | |
| 209 | rc = sched_group_set_rt_period(up->tg, rt_period); |
| 210 | |
| 211 | return (rc ? rc : size); |
| 212 | } |
| 213 | |
| 214 | static struct kobj_attribute cpu_rt_period_attr = |
| 215 | __ATTR(cpu_rt_period, 0644, cpu_rt_period_show, cpu_rt_period_store); |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 216 | #endif |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 217 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 218 | /* default attributes per uid directory */ |
| 219 | static struct attribute *uids_attributes[] = { |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 220 | #ifdef CONFIG_FAIR_GROUP_SCHED |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 221 | &cpu_share_attr.attr, |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 222 | #endif |
| 223 | #ifdef CONFIG_RT_GROUP_SCHED |
Peter Zijlstra | 9f0c1e5 | 2008-02-13 15:45:39 +0100 | [diff] [blame] | 224 | &cpu_rt_runtime_attr.attr, |
Peter Zijlstra | d0b27fa | 2008-04-19 19:44:57 +0200 | [diff] [blame] | 225 | &cpu_rt_period_attr.attr, |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 226 | #endif |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 227 | NULL |
| 228 | }; |
| 229 | |
| 230 | /* the lifetime of user_struct is not managed by the core (now) */ |
| 231 | static void uids_release(struct kobject *kobj) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 232 | { |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 233 | return; |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 234 | } |
| 235 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 236 | static struct kobj_type uids_ktype = { |
| 237 | .sysfs_ops = &kobj_sysfs_ops, |
| 238 | .default_attrs = uids_attributes, |
| 239 | .release = uids_release, |
| 240 | }; |
| 241 | |
Serge E. Hallyn | 94d6a5f | 2008-12-08 15:52:21 -0600 | [diff] [blame^] | 242 | /* |
| 243 | * Create /sys/kernel/uids/<uid>/cpu_share file for this user |
| 244 | * We do not create this file for users in a user namespace (until |
| 245 | * sysfs tagging is implemented). |
| 246 | * |
| 247 | * See Documentation/scheduler/sched-design-CFS.txt for ramifications. |
| 248 | */ |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 249 | static int uids_user_create(struct user_struct *up) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 250 | { |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 251 | struct kobject *kobj = &up->kobj; |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 252 | int error; |
| 253 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 254 | memset(kobj, 0, sizeof(struct kobject)); |
Serge E. Hallyn | c37bbb0 | 2008-12-03 13:17:06 -0600 | [diff] [blame] | 255 | if (up->user_ns != &init_user_ns) |
| 256 | return 0; |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 257 | kobj->kset = uids_kset; |
Greg Kroah-Hartman | cf15126 | 2007-12-17 23:05:35 -0700 | [diff] [blame] | 258 | error = kobject_init_and_add(kobj, &uids_ktype, NULL, "%d", up->uid); |
| 259 | if (error) { |
| 260 | kobject_put(kobj); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 261 | goto done; |
Greg Kroah-Hartman | cf15126 | 2007-12-17 23:05:35 -0700 | [diff] [blame] | 262 | } |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 263 | |
Srivatsa Vaddagiri | fb7dde3 | 2007-10-15 17:00:18 +0200 | [diff] [blame] | 264 | kobject_uevent(kobj, KOBJ_ADD); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 265 | done: |
| 266 | return error; |
| 267 | } |
| 268 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 269 | /* create these entries in sysfs: |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 270 | * "/sys/kernel/uids" directory |
| 271 | * "/sys/kernel/uids/0" directory (for root user) |
| 272 | * "/sys/kernel/uids/0/cpu_share" file (for root user) |
| 273 | */ |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 274 | int __init uids_sysfs_init(void) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 275 | { |
Greg Kroah-Hartman | 0ff21e4 | 2007-11-06 10:36:58 -0800 | [diff] [blame] | 276 | uids_kset = kset_create_and_add("uids", NULL, kernel_kobj); |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 277 | if (!uids_kset) |
| 278 | return -ENOMEM; |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 279 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 280 | return uids_user_create(&root_user); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 281 | } |
| 282 | |
| 283 | /* work function to remove sysfs directory for a user and free up |
| 284 | * corresponding structures. |
| 285 | */ |
| 286 | static void remove_user_sysfs_dir(struct work_struct *w) |
| 287 | { |
| 288 | struct user_struct *up = container_of(w, struct user_struct, work); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 289 | unsigned long flags; |
| 290 | int remove_user = 0; |
| 291 | |
Serge E. Hallyn | c37bbb0 | 2008-12-03 13:17:06 -0600 | [diff] [blame] | 292 | if (up->user_ns != &init_user_ns) |
| 293 | return; |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 294 | /* Make uid_hash_remove() + sysfs_remove_file() + kobject_del() |
| 295 | * atomic. |
| 296 | */ |
| 297 | uids_mutex_lock(); |
| 298 | |
| 299 | local_irq_save(flags); |
| 300 | |
| 301 | if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) { |
| 302 | uid_hash_remove(up); |
| 303 | remove_user = 1; |
| 304 | spin_unlock_irqrestore(&uidhash_lock, flags); |
| 305 | } else { |
| 306 | local_irq_restore(flags); |
| 307 | } |
| 308 | |
| 309 | if (!remove_user) |
| 310 | goto done; |
| 311 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 312 | kobject_uevent(&up->kobj, KOBJ_REMOVE); |
| 313 | kobject_del(&up->kobj); |
| 314 | kobject_put(&up->kobj); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 315 | |
| 316 | sched_destroy_user(up); |
| 317 | key_put(up->uid_keyring); |
| 318 | key_put(up->session_keyring); |
| 319 | kmem_cache_free(uid_cachep, up); |
| 320 | |
| 321 | done: |
| 322 | uids_mutex_unlock(); |
| 323 | } |
| 324 | |
| 325 | /* IRQs are disabled and uidhash_lock is held upon function entry. |
| 326 | * IRQ state (as stored in flags) is restored and uidhash_lock released |
| 327 | * upon function exit. |
| 328 | */ |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 329 | static void free_user(struct user_struct *up, unsigned long flags) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 330 | { |
| 331 | /* restore back the count */ |
| 332 | atomic_inc(&up->__count); |
| 333 | spin_unlock_irqrestore(&uidhash_lock, flags); |
| 334 | |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 335 | put_user_ns(up->user_ns); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 336 | INIT_WORK(&up->work, remove_user_sysfs_dir); |
| 337 | schedule_work(&up->work); |
| 338 | } |
| 339 | |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 340 | #else /* CONFIG_USER_SCHED && CONFIG_SYSFS */ |
Srivatsa Vaddagiri | 24e377a | 2007-10-15 17:00:09 +0200 | [diff] [blame] | 341 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 342 | int uids_sysfs_init(void) { return 0; } |
| 343 | static inline int uids_user_create(struct user_struct *up) { return 0; } |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 344 | static inline void uids_mutex_lock(void) { } |
| 345 | static inline void uids_mutex_unlock(void) { } |
| 346 | |
| 347 | /* IRQs are disabled and uidhash_lock is held upon function entry. |
| 348 | * IRQ state (as stored in flags) is restored and uidhash_lock released |
| 349 | * upon function exit. |
| 350 | */ |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 351 | static void free_user(struct user_struct *up, unsigned long flags) |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 352 | { |
| 353 | uid_hash_remove(up); |
| 354 | spin_unlock_irqrestore(&uidhash_lock, flags); |
| 355 | sched_destroy_user(up); |
| 356 | key_put(up->uid_keyring); |
| 357 | key_put(up->session_keyring); |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 358 | put_user_ns(up->user_ns); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 359 | kmem_cache_free(uid_cachep, up); |
| 360 | } |
Srivatsa Vaddagiri | 24e377a | 2007-10-15 17:00:09 +0200 | [diff] [blame] | 361 | |
Dhaval Giani | b1a8c17 | 2007-10-17 16:55:11 +0200 | [diff] [blame] | 362 | #endif |
Srivatsa Vaddagiri | 24e377a | 2007-10-15 17:00:09 +0200 | [diff] [blame] | 363 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 365 | * Locate the user_struct for the passed UID. If found, take a ref on it. The |
| 366 | * caller must undo that ref with free_uid(). |
| 367 | * |
| 368 | * If the user_struct could not be found, return NULL. |
| 369 | */ |
| 370 | struct user_struct *find_user(uid_t uid) |
| 371 | { |
| 372 | struct user_struct *ret; |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 373 | unsigned long flags; |
Serge Hallyn | 6ded6ab | 2008-11-24 16:24:10 -0500 | [diff] [blame] | 374 | struct user_namespace *ns = current_user_ns(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 376 | spin_lock_irqsave(&uidhash_lock, flags); |
Cedric Le Goater | acce292 | 2007-07-15 23:40:59 -0700 | [diff] [blame] | 377 | ret = uid_hash_find(uid, uidhashentry(ns, uid)); |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 378 | spin_unlock_irqrestore(&uidhash_lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | return ret; |
| 380 | } |
| 381 | |
| 382 | void free_uid(struct user_struct *up) |
| 383 | { |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 384 | unsigned long flags; |
| 385 | |
Andrew Morton | 36f5741 | 2006-03-24 03:15:47 -0800 | [diff] [blame] | 386 | if (!up) |
| 387 | return; |
| 388 | |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 389 | local_irq_save(flags); |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 390 | if (atomic_dec_and_lock(&up->__count, &uidhash_lock)) |
| 391 | free_user(up, flags); |
| 392 | else |
Andrew Morton | 36f5741 | 2006-03-24 03:15:47 -0800 | [diff] [blame] | 393 | local_irq_restore(flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | } |
| 395 | |
Andrew Morton | 354a1f4 | 2008-04-30 00:54:54 -0700 | [diff] [blame] | 396 | struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 397 | { |
Pavel Emelyanov | 735de22 | 2007-09-18 22:46:44 -0700 | [diff] [blame] | 398 | struct hlist_head *hashent = uidhashentry(ns, uid); |
Pavel Emelyanov | 8eb703e | 2008-01-25 21:08:26 +0100 | [diff] [blame] | 399 | struct user_struct *up, *new; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 400 | |
Kay Sievers | eb41d94 | 2007-11-02 13:47:53 +0100 | [diff] [blame] | 401 | /* Make uid_hash_find() + uids_user_create() + uid_hash_insert() |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 402 | * atomic. |
| 403 | */ |
| 404 | uids_mutex_lock(); |
| 405 | |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 406 | spin_lock_irq(&uidhash_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | up = uid_hash_find(uid, hashent); |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 408 | spin_unlock_irq(&uidhash_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | |
| 410 | if (!up) { |
Andrew Morton | 354a1f4 | 2008-04-30 00:54:54 -0700 | [diff] [blame] | 411 | new = kmem_cache_zalloc(uid_cachep, GFP_KERNEL); |
Pavel Emelyanov | 8eb703e | 2008-01-25 21:08:26 +0100 | [diff] [blame] | 412 | if (!new) |
| 413 | goto out_unlock; |
Pavel Emelyanov | 5e8869b | 2007-11-26 21:21:49 +0100 | [diff] [blame] | 414 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | new->uid = uid; |
| 416 | atomic_set(&new->__count, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
Pavel Emelyanov | 8eb703e | 2008-01-25 21:08:26 +0100 | [diff] [blame] | 418 | if (sched_create_user(new) < 0) |
David Howells | 69664cf | 2008-04-29 01:01:31 -0700 | [diff] [blame] | 419 | goto out_free_user; |
Srivatsa Vaddagiri | 24e377a | 2007-10-15 17:00:09 +0200 | [diff] [blame] | 420 | |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 421 | new->user_ns = get_user_ns(ns); |
| 422 | |
Pavel Emelyanov | 8eb703e | 2008-01-25 21:08:26 +0100 | [diff] [blame] | 423 | if (uids_user_create(new)) |
| 424 | goto out_destoy_sched; |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 425 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | /* |
| 427 | * Before adding this, check whether we raced |
| 428 | * on adding the same user already.. |
| 429 | */ |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 430 | spin_lock_irq(&uidhash_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 431 | up = uid_hash_find(uid, hashent); |
| 432 | if (up) { |
Peter Zijlstra | 052f1dc | 2008-02-13 15:45:40 +0100 | [diff] [blame] | 433 | /* This case is not possible when CONFIG_USER_SCHED |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 434 | * is defined, since we serialize alloc_uid() using |
| 435 | * uids_mutex. Hence no need to call |
| 436 | * sched_destroy_user() or remove_user_sysfs_dir(). |
| 437 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | key_put(new->uid_keyring); |
| 439 | key_put(new->session_keyring); |
| 440 | kmem_cache_free(uid_cachep, new); |
| 441 | } else { |
| 442 | uid_hash_insert(new, hashent); |
| 443 | up = new; |
| 444 | } |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 445 | spin_unlock_irq(&uidhash_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | } |
Dhaval Giani | 5cb350b | 2007-10-15 17:00:14 +0200 | [diff] [blame] | 447 | |
| 448 | uids_mutex_unlock(); |
| 449 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | return up; |
Pavel Emelyanov | 8eb703e | 2008-01-25 21:08:26 +0100 | [diff] [blame] | 451 | |
| 452 | out_destoy_sched: |
| 453 | sched_destroy_user(new); |
Serge Hallyn | 18b6e04 | 2008-10-15 16:38:45 -0500 | [diff] [blame] | 454 | put_user_ns(new->user_ns); |
Pavel Emelyanov | 8eb703e | 2008-01-25 21:08:26 +0100 | [diff] [blame] | 455 | out_free_user: |
| 456 | kmem_cache_free(uid_cachep, new); |
| 457 | out_unlock: |
| 458 | uids_mutex_unlock(); |
| 459 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | } |
| 461 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | static int __init uid_cache_init(void) |
| 463 | { |
| 464 | int n; |
| 465 | |
| 466 | uid_cachep = kmem_cache_create("uid_cache", sizeof(struct user_struct), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 467 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | |
| 469 | for(n = 0; n < UIDHASH_SZ; ++n) |
Pavel Emelyanov | 735de22 | 2007-09-18 22:46:44 -0700 | [diff] [blame] | 470 | INIT_HLIST_HEAD(init_user_ns.uidhash_table + n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | |
| 472 | /* Insert the root user immediately (init already runs as root) */ |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 473 | spin_lock_irq(&uidhash_lock); |
Cedric Le Goater | acce292 | 2007-07-15 23:40:59 -0700 | [diff] [blame] | 474 | uid_hash_insert(&root_user, uidhashentry(&init_user_ns, 0)); |
Andrew Morton | 3fa97c9 | 2006-01-31 16:34:26 -0800 | [diff] [blame] | 475 | spin_unlock_irq(&uidhash_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | |
| 477 | return 0; |
| 478 | } |
| 479 | |
| 480 | module_init(uid_cache_init); |