2 * Copyright (C) 2012-2016 ARM Limited. All rights reserved.
4 * This program is free software and is provided to you under the terms of the GNU General Public License version 2
5 * as published by the Free Software Foundation, and any use by you of this program is subject to the terms of such GNU licence.
7 * A copy of the licence is included with the program, and can also be obtained from Free Software
8 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
11 #include <linux/init.h>
12 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/cdev.h>
16 #include <linux/device.h>
17 #include <asm/uaccess.h>
18 #include "umplock_ioctl.h"
19 #include <linux/sched.h>
21 #define MAX_ITEMS 1024
24 typedef struct lock_cmd_priv {
25 uint32_t msg[128]; /*ioctl args*/
26 u32 pid; /*process id*/
29 typedef struct lock_ref {
35 typedef struct umplock_item {
39 _lock_access_usage usage;
40 _lock_ref references[MAX_PIDS];
41 struct semaphore item_lock;
44 typedef struct umplock_device_private {
45 struct mutex item_list_lock;
47 umplock_item items[MAX_ITEMS];
49 } umplock_device_private;
51 struct umplock_device {
53 struct class *umplock_class;
56 static struct umplock_device umplock_device;
57 static umplock_device_private device;
58 static dev_t umplock_dev;
59 static char umplock_dev_name[] = "umplock";
61 int umplock_debug_level = 0;
62 module_param(umplock_debug_level, int, S_IRUSR | S_IWUSR | S_IWGRP | S_IRGRP | S_IROTH); /* rw-rw-r-- */
63 MODULE_PARM_DESC(umplock_debug_level, "set umplock_debug_level to print debug messages");
65 #define PDEBUG(level, fmt, args...) do { if ((level) <= umplock_debug_level) printk(KERN_DEBUG "umplock: " fmt, ##args); } while (0)
66 #define PERROR(fmt, args...) do { printk(KERN_ERR "umplock: " fmt, ##args); } while (0)
68 int umplock_find_item(u32 secure_id)
71 for (i = 0; i < MAX_ITEMS; i++) {
72 if (device.items[i].secure_id == secure_id) {
80 static int umplock_find_item_by_pid(_lock_cmd_priv *lock_cmd, int *item_slot, int *ref_slot)
82 _lock_item_s *lock_item;
85 lock_item = (_lock_item_s *)&lock_cmd->msg;
87 i = umplock_find_item(lock_item->secure_id);
93 for (j = 0; j < MAX_PIDS; j++) {
94 if (device.items[i].references[j].pid == lock_cmd->pid) {
103 static int umplock_find_client_valid(u32 pid)
111 for (i = 0; i < MAX_PIDS; i++) {
112 if (device.pids[i] == pid) {
120 static int do_umplock_create_locked(_lock_cmd_priv *lock_cmd)
122 int i_index, ref_index;
124 _lock_item_s *lock_item = (_lock_item_s *)&lock_cmd->msg;
126 i_index = ref_index = -1;
128 ret = umplock_find_client_valid(lock_cmd->pid);
130 /*lock request from an invalid client pid, do nothing*/
134 ret = umplock_find_item_by_pid(lock_cmd, &i_index, &ref_index);
136 } else if ((i_index = umplock_find_item(lock_item->secure_id)) >= 0) {
137 for (ref_index = 0; ref_index < MAX_PIDS; ref_index++) {
138 if (device.items[i_index].references[ref_index].pid == 0) {
142 if (ref_index < MAX_PIDS) {
143 device.items[i_index].references[ref_index].pid = lock_cmd->pid;
144 device.items[i_index].references[ref_index].ref_count = 0;
145 device.items[i_index].references[ref_index].down_count = 0;
147 PERROR("whoops, item ran out of available reference slots\n");
152 i_index = umplock_find_item(0);
155 device.items[i_index].secure_id = lock_item->secure_id;
156 device.items[i_index].id_ref_count = 0;
157 device.items[i_index].usage = lock_item->usage;
158 device.items[i_index].references[0].pid = lock_cmd->pid;
159 device.items[i_index].references[0].ref_count = 0;
160 device.items[i_index].references[0].down_count = 0;
161 sema_init(&device.items[i_index].item_lock, 1);
163 PERROR("whoops, ran out of available slots\n");
172 static int do_umplock_create(_lock_cmd_priv *lock_cmd)
177 static int do_umplock_process(_lock_cmd_priv *lock_cmd)
179 int ret, i_index, ref_index;
180 _lock_item_s *lock_item = (_lock_item_s *)&lock_cmd->msg;
182 mutex_lock(&device.item_list_lock);
184 if (0 == lock_item->secure_id) {
185 PERROR("IOCTL_UMPLOCK_PROCESS called with secure_id is 0, pid: %d\n", lock_cmd->pid);
186 mutex_unlock(&device.item_list_lock);
190 ret = do_umplock_create_locked(lock_cmd);
192 mutex_unlock(&device.item_list_lock);
196 ret = umplock_find_item_by_pid(lock_cmd, &i_index, &ref_index);
198 /*fail to find a item*/
199 PERROR("IOCTL_UMPLOCK_PROCESS called with invalid parameter, pid: %d\n", lock_cmd->pid);
200 mutex_unlock(&device.item_list_lock);
203 device.items[i_index].references[ref_index].ref_count++;
204 device.items[i_index].id_ref_count++;
205 PDEBUG(1, "try to lock, pid: %d, secure_id: 0x%x, ref_count: %d\n", lock_cmd->pid, lock_item->secure_id, device.items[i_index].references[ref_index].ref_count);
207 if (lock_cmd->pid == device.items[i_index].owner) {
208 PDEBUG(1, "already own the lock, pid: %d, secure_id: 0x%x, ref_count: %d\n", lock_cmd->pid, lock_item->secure_id, device.items[i_index].references[ref_index].ref_count);
209 mutex_unlock(&device.item_list_lock);
213 device.items[i_index].references[ref_index].down_count++;
214 mutex_unlock(&device.item_list_lock);
215 if (down_interruptible(&device.items[i_index].item_lock)) {
216 /*wait up without hold the umplock. restore previous state and return*/
217 mutex_lock(&device.item_list_lock);
218 device.items[i_index].references[ref_index].ref_count--;
219 device.items[i_index].id_ref_count--;
220 device.items[i_index].references[ref_index].down_count--;
221 if (0 == device.items[i_index].references[ref_index].ref_count) {
222 device.items[i_index].references[ref_index].pid = 0;
223 if (0 == device.items[i_index].id_ref_count) {
224 PDEBUG(1, "release item, pid: %d, secure_id: 0x%x\n", lock_cmd->pid, lock_item->secure_id);
225 device.items[i_index].secure_id = 0;
229 PERROR("failed lock, pid: %d, secure_id: 0x%x, ref_count: %d\n", lock_cmd->pid, lock_item->secure_id, device.items[i_index].references[ref_index].ref_count);
231 mutex_unlock(&device.item_list_lock);
235 mutex_lock(&device.item_list_lock);
236 PDEBUG(1, "got lock, pid: %d, secure_id: 0x%x, ref_count: %d\n", lock_cmd->pid, lock_item->secure_id, device.items[i_index].references[ref_index].ref_count);
237 device.items[i_index].owner = lock_cmd->pid;
238 mutex_unlock(&device.item_list_lock);
243 static int do_umplock_release(_lock_cmd_priv *lock_cmd)
245 int ret, i_index, ref_index, call_up;
246 _lock_item_s *lock_item = (_lock_item_s *)&lock_cmd->msg;
248 mutex_lock(&device.item_list_lock);
250 if (0 == lock_item->secure_id) {
251 PERROR("IOCTL_UMPLOCK_RELEASE called with secure_id is 0, pid: %d\n", lock_cmd->pid);
252 mutex_unlock(&device.item_list_lock);
256 ret = umplock_find_client_valid(lock_cmd->pid);
258 /*lock request from an invalid client pid, do nothing*/
259 mutex_unlock(&device.item_list_lock);
263 i_index = ref_index = -1;
265 ret = umplock_find_item_by_pid(lock_cmd, &i_index, &ref_index);
267 /*fail to find item*/
268 PERROR("IOCTL_UMPLOCK_RELEASE called with invalid parameter pid: %d, secid: 0x%x\n", lock_cmd->pid, lock_item->secure_id);
269 mutex_unlock(&device.item_list_lock);
273 /* if the lock is not owned by this process */
274 if (lock_cmd->pid != device.items[i_index].owner) {
275 mutex_unlock(&device.item_list_lock);
279 /* if the ref_count is 0, that means nothing to unlock, just return */
280 if (0 == device.items[i_index].references[ref_index].ref_count) {
281 mutex_unlock(&device.item_list_lock);
285 device.items[i_index].references[ref_index].ref_count--;
286 device.items[i_index].id_ref_count--;
287 PDEBUG(1, "unlock, pid: %d, secure_id: 0x%x, ref_count: %d\n", lock_cmd->pid, lock_item->secure_id, device.items[i_index].references[ref_index].ref_count);
290 if (device.items[i_index].references[ref_index].down_count > 1) {
292 device.items[i_index].references[ref_index].down_count--;
294 if (0 == device.items[i_index].references[ref_index].ref_count) {
295 device.items[i_index].references[ref_index].pid = 0;
296 if (0 == device.items[i_index].id_ref_count) {
297 PDEBUG(1, "release item, pid: %d, secure_id: 0x%x\n", lock_cmd->pid, lock_item->secure_id);
298 device.items[i_index].secure_id = 0;
300 device.items[i_index].owner = 0;
304 PDEBUG(1, "call up, pid: %d, secure_id: 0x%x\n", lock_cmd->pid, lock_item->secure_id);
305 up(&device.items[i_index].item_lock);
307 mutex_unlock(&device.item_list_lock);
312 static int do_umplock_zap(void)
316 PDEBUG(1, "ZAP ALL ENTRIES!\n");
318 mutex_lock(&device.item_list_lock);
320 for (i = 0; i < MAX_ITEMS; i++) {
321 device.items[i].secure_id = 0;
322 memset(&device.items[i].references, 0, sizeof(_lock_ref) * MAX_PIDS);
323 sema_init(&device.items[i].item_lock, 1);
326 for (i = 0; i < MAX_PIDS; i++) {
329 mutex_unlock(&device.item_list_lock);
334 static int do_umplock_dump(void)
338 mutex_lock(&device.item_list_lock);
339 PERROR("dump all the items begin\n");
340 for (i = 0; i < MAX_ITEMS; i++) {
341 for (j = 0; j < MAX_PIDS; j++) {
342 if (device.items[i].secure_id != 0 && device.items[i].references[j].pid != 0) {
343 PERROR("item[%d]->secure_id=0x%x, owner=%d\t reference[%d].ref_count=%d.pid=%d\n",
345 device.items[i].secure_id,
346 device.items[i].owner,
348 device.items[i].references[j].ref_count,
349 device.items[i].references[j].pid);
353 PERROR("dump all the items end\n");
354 mutex_unlock(&device.item_list_lock);
359 int do_umplock_client_add(_lock_cmd_priv *lock_cmd)
362 mutex_lock(&device.item_list_lock);
363 for (i = 0; i < MAX_PIDS; i++) {
364 if (device.pids[i] == lock_cmd->pid) {
365 mutex_unlock(&device.item_list_lock);
369 for (i = 0; i < MAX_PIDS; i++) {
370 if (device.pids[i] == 0) {
371 device.pids[i] = lock_cmd->pid;
375 mutex_unlock(&device.item_list_lock);
377 PERROR("Oops, Run out of client slots\n ");
383 int do_umplock_client_delete(_lock_cmd_priv *lock_cmd)
385 int p_index = -1, i_index = -1, ref_index = -1;
387 _lock_item_s *lock_item;
388 lock_item = (_lock_item_s *)&lock_cmd->msg;
390 mutex_lock(&device.item_list_lock);
391 p_index = umplock_find_client_valid(lock_cmd->pid);
392 /*lock item pid is not valid.*/
394 mutex_unlock(&device.item_list_lock);
398 /*walk through umplock item list and release reference attached to this client*/
399 for (i_index = 0; i_index < MAX_ITEMS; i_index++) {
400 lock_item->secure_id = device.items[i_index].secure_id;
402 /*find the item index and reference slot for the lock_item*/
403 ret = umplock_find_item_by_pid(lock_cmd, &i_index, &ref_index);
406 /*client has no reference on this umplock item, skip*/
409 while (device.items[i_index].references[ref_index].ref_count) {
410 /*release references on this client*/
412 PDEBUG(1, "delete client, pid: %d, ref_count: %d\n", lock_cmd->pid, device.items[i_index].references[ref_index].ref_count);
414 mutex_unlock(&device.item_list_lock);
415 do_umplock_release(lock_cmd);
416 mutex_lock(&device.item_list_lock);
420 /*remove the pid from umplock valid pid list*/
421 device.pids[p_index] = 0;
422 mutex_unlock(&device.item_list_lock);
427 static long umplock_driver_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
430 uint32_t size = _IOC_SIZE(cmd);
431 _lock_cmd_priv lock_cmd ;
433 if (_IOC_TYPE(cmd) != LOCK_IOCTL_GROUP) {
437 if (_IOC_NR(cmd) >= LOCK_IOCTL_MAX_CMDS) {
442 case LOCK_IOCTL_CREATE:
443 if (size != sizeof(_lock_item_s)) {
447 if (copy_from_user(&lock_cmd.msg, (void __user *)arg, size)) {
450 lock_cmd.pid = (u32)current->tgid;
451 ret = do_umplock_create(&lock_cmd);
457 case LOCK_IOCTL_PROCESS:
458 if (size != sizeof(_lock_item_s)) {
462 if (copy_from_user(&lock_cmd.msg, (void __user *)arg, size)) {
465 lock_cmd.pid = (u32)current->tgid;
466 return do_umplock_process(&lock_cmd);
468 case LOCK_IOCTL_RELEASE:
469 if (size != sizeof(_lock_item_s)) {
473 if (copy_from_user(&lock_cmd.msg, (void __user *)arg, size)) {
476 lock_cmd.pid = (u32)current->tgid;
477 ret = do_umplock_release(&lock_cmd);
487 case LOCK_IOCTL_DUMP:
495 static int umplock_driver_open(struct inode *inode, struct file *filp)
497 _lock_cmd_priv lock_cmd;
499 atomic_inc(&device.sessions);
500 PDEBUG(1, "OPEN SESSION (%i references)\n", atomic_read(&device.sessions));
502 lock_cmd.pid = (u32)current->tgid;
503 do_umplock_client_add(&lock_cmd);
508 static int umplock_driver_release(struct inode *inode, struct file *filp)
511 _lock_cmd_priv lock_cmd;
513 lock_cmd.pid = (u32)current->tgid;
514 do_umplock_client_delete(&lock_cmd);
516 mutex_lock(&device.item_list_lock);
517 atomic_dec(&device.sessions);
518 sessions = atomic_read(&device.sessions);
519 PDEBUG(1, "CLOSE SESSION (%i references)\n", sessions);
520 mutex_unlock(&device.item_list_lock);
528 static struct file_operations umplock_fops = {
529 .owner = THIS_MODULE,
530 .open = umplock_driver_open,
531 .release = umplock_driver_release,
532 .unlocked_ioctl = umplock_driver_ioctl,
535 int umplock_device_initialize(void)
539 err = alloc_chrdev_region(&umplock_dev, 0, 1, umplock_dev_name);
542 memset(&umplock_device, 0, sizeof(umplock_device));
543 cdev_init(&umplock_device.cdev, &umplock_fops);
544 umplock_device.cdev.owner = THIS_MODULE;
545 umplock_device.cdev.ops = &umplock_fops;
547 err = cdev_add(&umplock_device.cdev, umplock_dev, 1);
549 umplock_device.umplock_class = class_create(THIS_MODULE, umplock_dev_name);
550 if (IS_ERR(umplock_device.umplock_class)) {
551 err = PTR_ERR(umplock_device.umplock_class);
554 mdev = device_create(umplock_device.umplock_class, NULL, umplock_dev, NULL, umplock_dev_name);
556 return 0; /* all ok */
560 class_destroy(umplock_device.umplock_class);
562 cdev_del(&umplock_device.cdev);
565 unregister_chrdev_region(umplock_dev, 1);
567 PERROR("alloc chardev region failed\n");
573 void umplock_device_terminate(void)
575 device_destroy(umplock_device.umplock_class, umplock_dev);
576 class_destroy(umplock_device.umplock_class);
578 cdev_del(&umplock_device.cdev);
579 unregister_chrdev_region(umplock_dev, 1);
582 static int __init umplock_initialize_module(void)
584 PDEBUG(1, "Inserting UMP lock device driver. Compiled: %s, time: %s\n", __DATE__, __TIME__);
586 mutex_init(&device.item_list_lock);
587 if (umplock_device_initialize() != 0) {
588 PERROR("UMP lock device driver init failed\n");
591 memset(&device.items, 0, sizeof(umplock_item) * MAX_ITEMS);
592 memset(&device.pids, 0, sizeof(u32) * MAX_PIDS);
593 atomic_set(&device.sessions, 0);
595 PDEBUG(1, "UMP lock device driver loaded\n");
600 static void __exit umplock_cleanup_module(void)
602 PDEBUG(1, "unloading UMP lock module\n");
604 memset(&device.items, 0, sizeof(umplock_item) * MAX_ITEMS);
605 memset(&device.pids, 0, sizeof(u32) * MAX_PIDS);
606 umplock_device_terminate();
607 mutex_destroy(&device.item_list_lock);
609 PDEBUG(1, "UMP lock module unloaded\n");
612 module_init(umplock_initialize_module);
613 module_exit(umplock_cleanup_module);
616 MODULE_LICENSE("GPL");
617 MODULE_AUTHOR("ARM Ltd.");
618 MODULE_DESCRIPTION("ARM UMP locker");