fs/ecryptfs/messaging.c

   1 /**
   2  * eCryptfs: Linux filesystem encryption layer
   3  *
   4  * Copyright (C) 2004-2008 International Business Machines Corp.
   5  *   Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
   6  *              Tyler Hicks <tyhicks@ou.edu>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22 #include <linux/sched.h>
  23 #include <linux/slab.h>
  24 #include <linux/user_namespace.h>
  25 #include <linux/nsproxy.h>
  26 #include "ecryptfs_kernel.h"
  27
  28 static LIST_HEAD(ecryptfs_msg_ctx_free_list);
  29 static LIST_HEAD(ecryptfs_msg_ctx_alloc_list);
  30 static struct mutex ecryptfs_msg_ctx_lists_mux;
  31
  32 static struct hlist_head *ecryptfs_daemon_hash;
  33 struct mutex ecryptfs_daemon_hash_mux;
  34 static int ecryptfs_hash_bits;
  35 #define ecryptfs_uid_hash(uid) \
  36         hash_long((unsigned long)uid, ecryptfs_hash_bits)
  37
  38 static u32 ecryptfs_msg_counter;
  39 static struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr;
  40
  41 /**
  42  * ecryptfs_acquire_free_msg_ctx
  43  * @msg_ctx: The context that was acquired from the free list
  44  *
  45  * Acquires a context element from the free list and locks the mutex
  46  * on the context.  Sets the msg_ctx task to current.  Returns zero on
  47  * success; non-zero on error or upon failure to acquire a free
  48  * context element.  Must be called with ecryptfs_msg_ctx_lists_mux
  49  * held.
  50  */
  51 static int ecryptfs_acquire_free_msg_ctx(struct ecryptfs_msg_ctx **msg_ctx)
  52 {
  53         struct list_head *p;
  54         int rc;
  55
  56         if (list_empty(&ecryptfs_msg_ctx_free_list)) {
  57                 printk(KERN_WARNING "%s: The eCryptfs free "
  58                        "context list is empty.  It may be helpful to "
  59                        "specify the ecryptfs_message_buf_len "
  60                        "parameter to be greater than the current "
  61                        "value of [%d]\n", __func__, ecryptfs_message_buf_len);
  62                 rc = -ENOMEM;
  63                 goto out;
  64         }
  65         list_for_each(p, &ecryptfs_msg_ctx_free_list) {
  66                 *msg_ctx = list_entry(p, struct ecryptfs_msg_ctx, node);
  67                 if (mutex_trylock(&(*msg_ctx)->mux)) {
  68                         (*msg_ctx)->task = current;
  69                         rc = 0;
  70                         goto out;
  71                 }
  72         }
  73         rc = -ENOMEM;
  74 out:
  75         return rc;
  76 }
  77
  78 /**
  79  * ecryptfs_msg_ctx_free_to_alloc
  80  * @msg_ctx: The context to move from the free list to the alloc list
  81  *
  82  * Must be called with ecryptfs_msg_ctx_lists_mux held.
  83  */
  84 static void ecryptfs_msg_ctx_free_to_alloc(struct ecryptfs_msg_ctx *msg_ctx)
  85 {
  86         list_move(&msg_ctx->node, &ecryptfs_msg_ctx_alloc_list);
  87         msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_PENDING;
  88         msg_ctx->counter = ++ecryptfs_msg_counter;
  89 }
  90
  91 /**
  92  * ecryptfs_msg_ctx_alloc_to_free
  93  * @msg_ctx: The context to move from the alloc list to the free list
  94  *
  95  * Must be called with ecryptfs_msg_ctx_lists_mux held.
  96  */
  97 void ecryptfs_msg_ctx_alloc_to_free(struct ecryptfs_msg_ctx *msg_ctx)
  98 {
  99         list_move(&(msg_ctx->node), &ecryptfs_msg_ctx_free_list);
 100         if (msg_ctx->msg)
 101                 kfree(msg_ctx->msg);
 102         msg_ctx->msg = NULL;
 103         msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_FREE;
 104 }
 105
 106 /**
 107  * ecryptfs_find_daemon_by_euid
 108  * @euid: The effective user id which maps to the desired daemon id
 109  * @user_ns: The namespace in which @euid applies
 110  * @daemon: If return value is zero, points to the desired daemon pointer
 111  *
 112  * Must be called with ecryptfs_daemon_hash_mux held.
 113  *
 114  * Search the hash list for the given user id.
 115  *
 116  * Returns zero if the user id exists in the list; non-zero otherwise.
 117  */
 118 int ecryptfs_find_daemon_by_euid(struct ecryptfs_daemon **daemon, uid_t euid,
 119                                  struct user_namespace *user_ns)
 120 {
 121         struct hlist_node *elem;
 122         int rc;
 123
 124         hlist_for_each_entry(*daemon, elem,
 125                              &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)],
 126                              euid_chain) {
 127                 if ((*daemon)->euid == euid && (*daemon)->user_ns == user_ns) {
 128                         rc = 0;
 129                         goto out;
 130                 }
 131         }
 132         rc = -EINVAL;
 133 out:
 134         return rc;
 135 }
 136
 137 /**
 138  * ecryptfs_spawn_daemon - Create and initialize a new daemon struct
 139  * @daemon: Pointer to set to newly allocated daemon struct
 140  * @euid: Effective user id for the daemon
 141  * @user_ns: The namespace in which @euid applies
 142  * @pid: Process id for the daemon
 143  *
 144  * Must be called ceremoniously while in possession of
 145  * ecryptfs_sacred_daemon_hash_mux
 146  *
 147  * Returns zero on success; non-zero otherwise
 148  */
 149 int
 150 ecryptfs_spawn_daemon(struct ecryptfs_daemon **daemon, uid_t euid,
 151                       struct user_namespace *user_ns, struct pid *pid)
 152 {
 153         int rc = 0;
 154
 155         (*daemon) = kzalloc(sizeof(**daemon), GFP_KERNEL);
 156         if (!(*daemon)) {
 157                 rc = -ENOMEM;
 158                 printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of "
 159                        "GFP_KERNEL memory\n", __func__, sizeof(**daemon));
 160                 goto out;
 161         }
 162         (*daemon)->euid = euid;
 163         (*daemon)->user_ns = get_user_ns(user_ns);
 164         (*daemon)->pid = get_pid(pid);
 165         (*daemon)->task = current;
 166         mutex_init(&(*daemon)->mux);
 167         INIT_LIST_HEAD(&(*daemon)->msg_ctx_out_queue);
 168         init_waitqueue_head(&(*daemon)->wait);
 169         (*daemon)->num_queued_msg_ctx = 0;
 170         hlist_add_head(&(*daemon)->euid_chain,
 171                        &ecryptfs_daemon_hash[ecryptfs_uid_hash(euid)]);
 172 out:
 173         return rc;
 174 }
 175
 176 /**
 177  * ecryptfs_exorcise_daemon - Destroy the daemon struct
 178  *
 179  * Must be called ceremoniously while in possession of
 180  * ecryptfs_daemon_hash_mux and the daemon's own mux.
 181  */
 182 int ecryptfs_exorcise_daemon(struct ecryptfs_daemon *daemon)
 183 {
 184         struct ecryptfs_msg_ctx *msg_ctx, *msg_ctx_tmp;
 185         int rc = 0;
 186
 187         mutex_lock(&daemon->mux);
 188         if ((daemon->flags & ECRYPTFS_DAEMON_IN_READ)
 189             || (daemon->flags & ECRYPTFS_DAEMON_IN_POLL)) {
 190                 rc = -EBUSY;
 191                 printk(KERN_WARNING "%s: Attempt to destroy daemon with pid "
 192                        "[0x%p], but it is in the midst of a read or a poll\n",
 193                        __func__, daemon->pid);
 194                 mutex_unlock(&daemon->mux);
 195                 goto out;
 196         }
 197         list_for_each_entry_safe(msg_ctx, msg_ctx_tmp,
 198                                  &daemon->msg_ctx_out_queue, daemon_out_list) {
 199                 list_del(&msg_ctx->daemon_out_list);
 200                 daemon->num_queued_msg_ctx--;
 201                 printk(KERN_WARNING "%s: Warning: dropping message that is in "
 202                        "the out queue of a dying daemon\n", __func__);
 203                 ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
 204         }
 205         hlist_del(&daemon->euid_chain);
 206         if (daemon->task)
 207                 wake_up_process(daemon->task);
 208         if (daemon->pid)
 209                 put_pid(daemon->pid);
 210         if (daemon->user_ns)
 211                 put_user_ns(daemon->user_ns);
 212         mutex_unlock(&daemon->mux);
 213         kzfree(daemon);
 214 out:
 215         return rc;
 216 }
 217
 218 /**
 219  * ecryptfs_process_reponse
 220  * @msg: The ecryptfs message received; the caller should sanity check
 221  *       msg->data_len and free the memory
 222  * @pid: The process ID of the userspace application that sent the
 223  *       message
 224  * @seq: The sequence number of the message; must match the sequence
 225  *       number for the existing message context waiting for this
 226  *       response
 227  *
 228  * Processes a response message after sending an operation request to
 229  * userspace. Some other process is awaiting this response. Before
 230  * sending out its first communications, the other process allocated a
 231  * msg_ctx from the ecryptfs_msg_ctx_arr at a particular index. The
 232  * response message contains this index so that we can copy over the
 233  * response message into the msg_ctx that the process holds a
 234  * reference to. The other process is going to wake up, check to see
 235  * that msg_ctx->state == ECRYPTFS_MSG_CTX_STATE_DONE, and then
 236  * proceed to read off and process the response message. Returns zero
 237  * upon delivery to desired context element; non-zero upon delivery
 238  * failure or error.
 239  *
 240  * Returns zero on success; non-zero otherwise
 241  */
 242 int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t euid,
 243                               struct user_namespace *user_ns, struct pid *pid,
 244                               u32 seq)
 245 {
 246         struct ecryptfs_daemon *uninitialized_var(daemon);
 247         struct ecryptfs_msg_ctx *msg_ctx;
 248         size_t msg_size;
 249         struct nsproxy *nsproxy;
 250         struct user_namespace *tsk_user_ns;
 251         uid_t ctx_euid;
 252         int rc;
 253
 254         if (msg->index >= ecryptfs_message_buf_len) {
 255                 rc = -EINVAL;
 256                 printk(KERN_ERR "%s: Attempt to reference "
 257                        "context buffer at index [%d]; maximum "
 258                        "allowable is [%d]\n", __func__, msg->index,
 259                        (ecryptfs_message_buf_len - 1));
 260                 goto out;
 261         }
 262         msg_ctx = &ecryptfs_msg_ctx_arr[msg->index];
 263         mutex_lock(&msg_ctx->mux);
 264         mutex_lock(&ecryptfs_daemon_hash_mux);
 265         rcu_read_lock();
 266         nsproxy = task_nsproxy(msg_ctx->task);
 267         if (nsproxy == NULL) {
 268                 rc = -EBADMSG;
 269                 printk(KERN_ERR "%s: Receiving process is a zombie. Dropping "
 270                        "message.\n", __func__);
 271                 rcu_read_unlock();
 272                 mutex_unlock(&ecryptfs_daemon_hash_mux);
 273                 goto wake_up;
 274         }
 275         tsk_user_ns = __task_cred(msg_ctx->task)->user_ns;
 276         ctx_euid = task_euid(msg_ctx->task);
 277         rc = ecryptfs_find_daemon_by_euid(&daemon, ctx_euid, tsk_user_ns);
 278         rcu_read_unlock();
 279         mutex_unlock(&ecryptfs_daemon_hash_mux);
 280         if (rc) {
 281                 rc = -EBADMSG;
 282                 printk(KERN_WARNING "%s: User [%d] received a "
 283                        "message response from process [0x%p] but does "
 284                        "not have a registered daemon\n", __func__,
 285                        ctx_euid, pid);
 286                 goto wake_up;
 287         }
 288         if (ctx_euid != euid) {
 289                 rc = -EBADMSG;
 290                 printk(KERN_WARNING "%s: Received message from user "
 291                        "[%d]; expected message from user [%d]\n", __func__,
 292                        euid, ctx_euid);
 293                 goto unlock;
 294         }
 295         if (tsk_user_ns != user_ns) {
 296                 rc = -EBADMSG;
 297                 printk(KERN_WARNING "%s: Received message from user_ns "
 298                        "[0x%p]; expected message from user_ns [0x%p]\n",
 299                        __func__, user_ns, tsk_user_ns);
 300                 goto unlock;
 301         }
 302         if (daemon->pid != pid) {
 303                 rc = -EBADMSG;
 304                 printk(KERN_ERR "%s: User [%d] sent a message response "
 305                        "from an unrecognized process [0x%p]\n",
 306                        __func__, ctx_euid, pid);
 307                 goto unlock;
 308         }
 309         if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_PENDING) {
 310                 rc = -EINVAL;
 311                 printk(KERN_WARNING "%s: Desired context element is not "
 312                        "pending a response\n", __func__);
 313                 goto unlock;
 314         } else if (msg_ctx->counter != seq) {
 315                 rc = -EINVAL;
 316                 printk(KERN_WARNING "%s: Invalid message sequence; "
 317                        "expected [%d]; received [%d]\n", __func__,
 318                        msg_ctx->counter, seq);
 319                 goto unlock;
 320         }
 321         msg_size = (sizeof(*msg) + msg->data_len);
 322         msg_ctx->msg = kmalloc(msg_size, GFP_KERNEL);
 323         if (!msg_ctx->msg) {
 324                 rc = -ENOMEM;
 325                 printk(KERN_ERR "%s: Failed to allocate [%zd] bytes of "
 326                        "GFP_KERNEL memory\n", __func__, msg_size);
 327                 goto unlock;
 328         }
 329         memcpy(msg_ctx->msg, msg, msg_size);
 330         msg_ctx->state = ECRYPTFS_MSG_CTX_STATE_DONE;
 331         rc = 0;
 332 wake_up:
 333         wake_up_process(msg_ctx->task);
 334 unlock:
 335         mutex_unlock(&msg_ctx->mux);
 336 out:
 337         return rc;
 338 }
 339
 340 /**
 341  * ecryptfs_send_message_locked
 342  * @data: The data to send
 343  * @data_len: The length of data
 344  * @msg_ctx: The message context allocated for the send
 345  *
 346  * Must be called with ecryptfs_daemon_hash_mux held.
 347  *
 348  * Returns zero on success; non-zero otherwise
 349  */
 350 static int
 351 ecryptfs_send_message_locked(char *data, int data_len, u8 msg_type,
 352                              struct ecryptfs_msg_ctx **msg_ctx)
 353 {
 354         struct ecryptfs_daemon *daemon;
 355         uid_t euid = current_euid();
 356         int rc;
 357
 358         rc = ecryptfs_find_daemon_by_euid(&daemon, euid, current_user_ns());
 359         if (rc || !daemon) {
 360                 rc = -ENOTCONN;
 361                 printk(KERN_ERR "%s: User [%d] does not have a daemon "
 362                        "registered\n", __func__, euid);
 363                 goto out;
 364         }
 365         mutex_lock(&ecryptfs_msg_ctx_lists_mux);
 366         rc = ecryptfs_acquire_free_msg_ctx(msg_ctx);
 367         if (rc) {
 368                 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
 369                 printk(KERN_WARNING "%s: Could not claim a free "
 370                        "context element\n", __func__);
 371                 goto out;
 372         }
 373         ecryptfs_msg_ctx_free_to_alloc(*msg_ctx);
 374         mutex_unlock(&(*msg_ctx)->mux);
 375         mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
 376         rc = ecryptfs_send_miscdev(data, data_len, *msg_ctx, msg_type, 0,
 377                                    daemon);
 378         if (rc)
 379                 printk(KERN_ERR "%s: Error attempting to send message to "
 380                        "userspace daemon; rc = [%d]\n", __func__, rc);
 381 out:
 382         return rc;
 383 }
 384
 385 /**
 386  * ecryptfs_send_message
 387  * @data: The data to send
 388  * @data_len: The length of data
 389  * @msg_ctx: The message context allocated for the send
 390  *
 391  * Grabs ecryptfs_daemon_hash_mux.
 392  *
 393  * Returns zero on success; non-zero otherwise
 394  */
 395 int ecryptfs_send_message(char *data, int data_len,
 396                           struct ecryptfs_msg_ctx **msg_ctx)
 397 {
 398         int rc;
 399
 400         mutex_lock(&ecryptfs_daemon_hash_mux);
 401         rc = ecryptfs_send_message_locked(data, data_len, ECRYPTFS_MSG_REQUEST,
 402                                           msg_ctx);
 403         mutex_unlock(&ecryptfs_daemon_hash_mux);
 404         return rc;
 405 }
 406
 407 /**
 408  * ecryptfs_wait_for_response
 409  * @msg_ctx: The context that was assigned when sending a message
 410  * @msg: The incoming message from userspace; not set if rc != 0
 411  *
 412  * Sleeps until awaken by ecryptfs_receive_message or until the amount
 413  * of time exceeds ecryptfs_message_wait_timeout.  If zero is
 414  * returned, msg will point to a valid message from userspace; a
 415  * non-zero value is returned upon failure to receive a message or an
 416  * error occurs. Callee must free @msg on success.
 417  */
 418 int ecryptfs_wait_for_response(struct ecryptfs_msg_ctx *msg_ctx,
 419                                struct ecryptfs_message **msg)
 420 {
 421         signed long timeout = ecryptfs_message_wait_timeout * HZ;
 422         int rc = 0;
 423
 424 sleep:
 425         timeout = schedule_timeout_interruptible(timeout);
 426         mutex_lock(&ecryptfs_msg_ctx_lists_mux);
 427         mutex_lock(&msg_ctx->mux);
 428         if (msg_ctx->state != ECRYPTFS_MSG_CTX_STATE_DONE) {
 429                 if (timeout) {
 430                         mutex_unlock(&msg_ctx->mux);
 431                         mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
 432                         goto sleep;
 433                 }
 434                 rc = -ENOMSG;
 435         } else {
 436                 *msg = msg_ctx->msg;
 437                 msg_ctx->msg = NULL;
 438         }
 439         ecryptfs_msg_ctx_alloc_to_free(msg_ctx);
 440         mutex_unlock(&msg_ctx->mux);
 441         mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
 442         return rc;
 443 }
 444
 445 int __init ecryptfs_init_messaging(void)
 446 {
 447         int i;
 448         int rc = 0;
 449
 450         if (ecryptfs_number_of_users > ECRYPTFS_MAX_NUM_USERS) {
 451                 ecryptfs_number_of_users = ECRYPTFS_MAX_NUM_USERS;
 452                 printk(KERN_WARNING "%s: Specified number of users is "
 453                        "too large, defaulting to [%d] users\n", __func__,
 454                        ecryptfs_number_of_users);
 455         }
 456         mutex_init(&ecryptfs_daemon_hash_mux);
 457         mutex_lock(&ecryptfs_daemon_hash_mux);
 458         ecryptfs_hash_bits = 1;
 459         while (ecryptfs_number_of_users >> ecryptfs_hash_bits)
 460                 ecryptfs_hash_bits++;
 461         ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head)
 462                                         * (1 << ecryptfs_hash_bits)),
 463                                        GFP_KERNEL);
 464         if (!ecryptfs_daemon_hash) {
 465                 rc = -ENOMEM;
 466                 printk(KERN_ERR "%s: Failed to allocate memory\n", __func__);
 467                 mutex_unlock(&ecryptfs_daemon_hash_mux);
 468                 goto out;
 469         }
 470         for (i = 0; i < (1 << ecryptfs_hash_bits); i++)
 471                 INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]);
 472         mutex_unlock(&ecryptfs_daemon_hash_mux);
 473         ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx)
 474                                         * ecryptfs_message_buf_len),
 475                                        GFP_KERNEL);
 476         if (!ecryptfs_msg_ctx_arr) {
 477                 rc = -ENOMEM;
 478                 printk(KERN_ERR "%s: Failed to allocate memory\n", __func__);
 479                 goto out;
 480         }
 481         mutex_init(&ecryptfs_msg_ctx_lists_mux);
 482         mutex_lock(&ecryptfs_msg_ctx_lists_mux);
 483         ecryptfs_msg_counter = 0;
 484         for (i = 0; i < ecryptfs_message_buf_len; i++) {
 485                 INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].node);
 486                 INIT_LIST_HEAD(&ecryptfs_msg_ctx_arr[i].daemon_out_list);
 487                 mutex_init(&ecryptfs_msg_ctx_arr[i].mux);
 488                 mutex_lock(&ecryptfs_msg_ctx_arr[i].mux);
 489                 ecryptfs_msg_ctx_arr[i].index = i;
 490                 ecryptfs_msg_ctx_arr[i].state = ECRYPTFS_MSG_CTX_STATE_FREE;
 491                 ecryptfs_msg_ctx_arr[i].counter = 0;
 492                 ecryptfs_msg_ctx_arr[i].task = NULL;
 493                 ecryptfs_msg_ctx_arr[i].msg = NULL;
 494                 list_add_tail(&ecryptfs_msg_ctx_arr[i].node,
 495                               &ecryptfs_msg_ctx_free_list);
 496                 mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux);
 497         }
 498         mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
 499         rc = ecryptfs_init_ecryptfs_miscdev();
 500         if (rc)
 501                 ecryptfs_release_messaging();
 502 out:
 503         return rc;
 504 }
 505
 506 void ecryptfs_release_messaging(void)
 507 {
 508         if (ecryptfs_msg_ctx_arr) {
 509                 int i;
 510
 511                 mutex_lock(&ecryptfs_msg_ctx_lists_mux);
 512                 for (i = 0; i < ecryptfs_message_buf_len; i++) {
 513                         mutex_lock(&ecryptfs_msg_ctx_arr[i].mux);
 514                         if (ecryptfs_msg_ctx_arr[i].msg)
 515                                 kfree(ecryptfs_msg_ctx_arr[i].msg);
 516                         mutex_unlock(&ecryptfs_msg_ctx_arr[i].mux);
 517                 }
 518                 kfree(ecryptfs_msg_ctx_arr);
 519                 mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
 520         }
 521         if (ecryptfs_daemon_hash) {
 522                 struct hlist_node *elem;
 523                 struct ecryptfs_daemon *daemon;
 524                 int i;
 525
 526                 mutex_lock(&ecryptfs_daemon_hash_mux);
 527                 for (i = 0; i < (1 << ecryptfs_hash_bits); i++) {
 528                         int rc;
 529
 530                         hlist_for_each_entry(daemon, elem,
 531                                              &ecryptfs_daemon_hash[i],
 532                                              euid_chain) {
 533                                 rc = ecryptfs_exorcise_daemon(daemon);
 534                                 if (rc)
 535                                         printk(KERN_ERR "%s: Error whilst "
 536                                                "attempting to destroy daemon; "
 537                                                "rc = [%d]. Dazed and confused, "
 538                                                "but trying to continue.\n",
 539                                                __func__, rc);
 540                         }
 541                 }
 542                 kfree(ecryptfs_daemon_hash);
 543                 mutex_unlock(&ecryptfs_daemon_hash_mux);
 544         }
 545         ecryptfs_destroy_ecryptfs_miscdev();
 546         return;
 547 }