driver/device_driver.c

   1 ////////////////////////////////////////////////////////////////////////////////////
   2 //
   3 //      FILE:           device_driver.c
   4 //
   5 //      DESCRIPTION:
   6 //      This file is C source for SWAP driver.
   7 //
   8 //      SEE ALSO:       device_driver.h
   9 //      AUTHOR:         L.Komkov, S.Dianov, S.Grekhov, A.Gerenkov
  10 //      COMPANY NAME:   Samsung Research Center in Moscow
  11 //      DEPT NAME:      Advanced Software Group
  12 //      CREATED:        2008.02.15
  13 //      VERSION:        1.0
  14 //      REVISION DATE:  2008.12.03
  15 //
  16 ////////////////////////////////////////////////////////////////////////////////////
  17
  18 #include "module.h"
  19 #include "device_driver.h"      // device driver
  20 #include "handlers_core.h"
  21 #include <linux/notifier.h>
  22
  23 #ifdef OVERHEAD_DEBUG
  24 extern unsigned long swap_sum_time;
  25 extern unsigned long swap_sum_hit;
  26 #endif
  27
  28 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
  29 static BLOCKING_NOTIFIER_HEAD(swap_notifier_list);
  30 #endif
  31 pid_t gl_nNotifyTgid;
  32 EXPORT_SYMBOL_GPL(gl_nNotifyTgid);
  33
  34 DECLARE_WAIT_QUEUE_HEAD (notification_waiters_queue);
  35 volatile unsigned notification_count;
  36
  37 static int device_mmap (struct file *filp, struct vm_area_struct *vma);
  38 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
  39 static int device_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
  40 #else
  41 static long device_ioctl (struct file *file, unsigned int cmd, unsigned long arg);
  42 #endif
  43 static int device_open(struct inode *, struct file *);
  44 static int device_release(struct inode *, struct file *);
  45 static ssize_t device_read(struct file *, char *, size_t, loff_t *);
  46 static ssize_t device_write(struct file *, const char *, size_t, loff_t *);
  47
  48 static int gl_nDeviceOpened = 0;
  49 static struct file_operations device_fops = {
  50         .owner = THIS_MODULE,
  51         .mmap = device_mmap,
  52 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
  53         .ioctl = device_ioctl,
  54 #else
  55         .unlocked_ioctl = device_ioctl,
  56 #endif
  57         .read = device_read,
  58         .write = device_write,
  59         .open = device_open,
  60         .release = device_release
  61 };
  62
  63 typedef void (* dbi_module_callback)();
  64
  65 int device_init (void)
  66 {
  67         int nReserved = 0;
  68         int nRetVal = register_chrdev(device_major, device_name, &device_fops);
  69         if (nRetVal < 0) {
  70                 EPRINTF("Cannot register character device! [%s, %d]", device_name, device_major);
  71                 nReserved = register_chrdev(0, device_name, &device_fops);
  72                 if(nReserved >= 0)
  73                 {
  74                         unregister_chrdev(nReserved, device_name);
  75                         EPRINTF("Please, create a new device node with major number [%d],\n\tand pass it as module parameter!", nReserved);
  76                 }
  77                 return -1;
  78         } else if(nRetVal > 0) {
  79                 EPRINTF("Cannot register this device major number! [%d]\n\tTrying a new one. [%d]", device_major, nRetVal);
  80                 device_major = nRetVal;
  81         }
  82         return 0;
  83 }
  84
  85 void device_down (void)
  86 {
  87         unregister_chrdev(device_major, device_name);
  88 }
  89
  90 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
  91 void swap_register_notify (struct notifier_block *nb)
  92 {
  93         blocking_notifier_chain_register(&swap_notifier_list, nb);
  94 }
  95 EXPORT_SYMBOL_GPL(swap_register_notify);
  96
  97 void swap_unregister_notify (struct notifier_block *nb)
  98 {
  99         blocking_notifier_chain_unregister(&swap_notifier_list, nb);
 100 }
 101 EXPORT_SYMBOL_GPL(swap_unregister_notify);
 102 #endif
 103
 104 void notify_user (event_id_t event_id)
 105 {
 106         ec_info.events_counters[event_id] += 1;
 107
 108         if (EVENT_EC_PROBE_RECORD == event_id)
 109         {
 110                 // EC_PROBE_RECORD events happen to often. To reduce overhead user
 111                 // space will be notified only once per each EVENTS_AGGREGATION_USEC
 112                 static uint64_t timestamp_usec = 0;
 113
 114                 uint64_t current_usec;
 115                 uint64_t delta_usec;
 116
 117                 struct timeval tv;
 118
 119                 do_gettimeofday (&tv);
 120                 current_usec = 1000000ULL * (unsigned) tv.tv_sec + (unsigned) tv.tv_usec;
 121
 122                 if (current_usec < timestamp_usec)
 123                 {
 124                         // Note: time from do_gettimeofday() may go backward
 125                         EPRINTF ("current_usec=%llu timestamp_usec=%llu", current_usec, timestamp_usec);
 126                 }
 127                 else
 128                 {
 129                         delta_usec = current_usec - timestamp_usec;
 130                         if (EVENTS_AGGREGATION_USEC > delta_usec)
 131                         {
 132                                 // wait the time left
 133 #if defined(__DEBUG)
 134                                 unsigned UNUSED left_usec = EVENTS_AGGREGATION_USEC - delta_usec;
 135 #endif /* defined(__DEBUG) */
 136                                 return; // supress notification
 137                         }
 138                 }
 139                 timestamp_usec = current_usec;  // remember new time for the future use
 140         } else if (EVENT_EC_START_CONDITION_SEEN == event_id) {
 141                 return;         // supress notification
 142         } else if (EVENT_EC_STOP_CONDITION_SEEN == event_id) {
 143                 return;         // supress notification
 144         }
 145
 146         ++notification_count;
 147         wake_up_interruptible (&notification_waiters_queue);
 148 }
 149
 150 static int device_mmap (struct file *filp UNUSED, struct vm_area_struct *vma)
 151 {
 152         if(!p_buffer) {
 153                 EPRINTF("Null pointer to buffer!");
 154                 return -1;
 155         }
 156         return remap_vmalloc_range (vma, p_buffer, 0);
 157 }
 158
 159 static int device_open(struct inode *inode, struct file *file)
 160 {
 161         /*if (gl_nDeviceOpened)
 162                 return -EBUSY;*/
 163         gl_nDeviceOpened++;
 164         // TODO
 165         try_module_get(THIS_MODULE);
 166         return 0;
 167 }
 168
 169 static int device_release(struct inode *inode, struct file *file)
 170 {
 171         gl_nDeviceOpened--;
 172         module_put(THIS_MODULE);
 173         return 0;
 174 }
 175
 176 static ssize_t device_read(struct file *filp, char *buffer, size_t length, loff_t * offset)
 177 {
 178         EPRINTF("Operation <<read>> not supported!");
 179         return -1;
 180 }
 181
 182 static ssize_t device_write(struct file *filp, const char *buff, size_t len, loff_t * off)
 183 {
 184         EPRINTF("Operation <<write>> not supported!");
 185         return -1;
 186 }
 187
 188 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
 189 static int device_ioctl (struct inode *inode UNUSED, struct file *file UNUSED, unsigned int cmd, unsigned long arg)
 190 #else
 191 static long device_ioctl (struct file *file UNUSED, unsigned int cmd, unsigned long arg)
 192 #endif
 193 {
 194         unsigned long spinlock_flags = 0L;
 195         int result = -1;
 196 //      DPRINTF("Command=%d", cmd);
 197         switch (cmd)
 198         {
 199         case EC_IOCTL_SET_EC_MODE:
 200                 {
 201                         ioctl_general_t param;
 202                         unsigned long nIgnoredBytes = 0;
 203                         memset(&param, '0', sizeof(ioctl_general_t));
 204                         nIgnoredBytes = copy_from_user (&param, (void*)arg, sizeof(ioctl_general_t));
 205                         if (nIgnoredBytes > 0) {
 206                                 result = -1;
 207                                 break;
 208                         }
 209                         if(SetECMode(param.m_unsignedLong) == -1) {
 210                                 result = -1;
 211                                 break;
 212                         }
 213                         result = 0;
 214                         DPRINTF("Set EC Mode = %lu", param.m_unsignedLong);
 215                         break;
 216                 }
 217         case EC_IOCTL_GET_EC_MODE:
 218                 {
 219                         ioctl_general_t param;
 220                         unsigned long nIgnoredBytes = 0;
 221                         memset(&param, '0', sizeof(ioctl_general_t));
 222                         param.m_unsignedLong = GetECMode();
 223                         nIgnoredBytes = copy_to_user ((void*)arg, &param, sizeof (ioctl_general_t));
 224                         if (nIgnoredBytes > 0) {
 225                                 result = -1;
 226                                 break;
 227                         }
 228                         result = 0;
 229 //                      DPRINTF("Get EC Mode = %lu", param.m_unsignedLong);  // Frequent call
 230                         break;
 231                 }
 232         case EC_IOCTL_SET_BUFFER_SIZE:
 233                 {
 234                         ioctl_general_t param;
 235                         unsigned long nIgnoredBytes = 0;
 236                         memset(&param, '0', sizeof(ioctl_general_t));
 237                         nIgnoredBytes = copy_from_user (&param, (void*)arg, sizeof(ioctl_general_t));
 238                         if (nIgnoredBytes > 0) {
 239                                 result = -1;
 240                                 break;
 241                         }
 242                         if (SetBufferSize(param.m_unsignedLong) == -1) {
 243                                 result = -1;
 244                                 break;
 245                         }
 246                         result = 0;
 247                         DPRINTF("Set Buffer Size = %lu", param.m_unsignedLong);
 248                         break;
 249                 }
 250         case EC_IOCTL_GET_BUFFER_SIZE:
 251                 {
 252                         ioctl_general_t param;
 253                         unsigned long nIgnoredBytes = 0;
 254                         memset(&param, '0', sizeof(ioctl_general_t));
 255                         param.m_unsignedLong = GetBufferSize();
 256                         nIgnoredBytes = copy_to_user ((void*)arg, &param, sizeof (ioctl_general_t));
 257                         if (nIgnoredBytes > 0) {
 258                                 result = -1;
 259                                 break;
 260                         }
 261                         result = 0;
 262                         DPRINTF("Get Buffer Size = %lu", param.m_unsignedLong);
 263                         break;
 264                 }
 265         case EC_IOCTL_RESET_BUFFER:
 266                 {
 267                         if (ResetBuffer() == -1) {
 268                                 result = -1;
 269                                 break;
 270                         }
 271                         result = 0;
 272                         DPRINTF("Reset Buffer");
 273                         break;
 274                 }
 275         case EC_IOCTL_GET_EC_INFO:
 276                 {
 277                         if (copy_ec_info_to_user_space ((ec_info_t *) arg) != 0) {
 278                                 result = -1;
 279                                 break;
 280                         }
 281                         result = 0;
 282 //                      DPRINTF("Get Buffer Status"); // Frequent call
 283                         break;
 284                 }
 285         case EC_IOCTL_CONSUME_BUFFER:
 286                 {
 287                         static ec_info_t ec_info_copy;
 288                         int nIgnoredBytes = 0;
 289
 290                         nIgnoredBytes = copy_from_user (&ec_info_copy, (ec_info_t *) arg, sizeof (ec_info_t));
 291                         if(nIgnoredBytes > 0)
 292                         {
 293                                 EPRINTF ("copy_from_user(%08X,%08X)=%d", (unsigned) arg, (unsigned) &ec_info_copy, nIgnoredBytes);
 294                                 result = -1;
 295                                 break;
 296                         }
 297
 298                         spin_lock_irqsave (&ec_spinlock, spinlock_flags);
 299
 300                         // Original buffer
 301                         if(ec_info.after_last > ec_info.first) {
 302                                 ec_info.buffer_effect = ec_info.buffer_size;
 303                         }
 304                         if (ec_info.after_last == ec_info.buffer_effect) {
 305                                  ec_info.first = 0;
 306                         } else {
 307                                  ec_info.first = ec_info_copy.after_last;
 308                         }
 309                         ec_info.trace_size = ec_info.trace_size - ec_info_copy.trace_size;
 310
 311                         spin_unlock_irqrestore (&ec_spinlock, spinlock_flags);
 312                         result = 0;
 313 //                      DPRINTF("Consume Buffer"); // Frequent call
 314                         break;
 315                 }
 316         case EC_IOCTL_ADD_PROBE:
 317                 {
 318                         unsigned long addr = arg;
 319                         result = add_probe(addr);
 320
 321                         break;
 322                 }
 323         //@AGv: remove_probe expects probe address instead of name
 324         /*case EC_IOCTL_REMOVE_PROBE:
 325                 {
 326                         char *probe_name = (char *) arg;
 327                         result = remove_probe (probe_name);
 328
 329                         break;
 330                 }*/
 331         case EC_IOCTL_SET_APPDEPS:
 332         {
 333                 size_t size;
 334                 result = copy_from_user(&size, (void *)arg, sizeof(size_t));
 335                 if (result) {
 336                         EPRINTF("Cannot copy deps size!");
 337                         result = -1;
 338                         break;
 339                 }
 340                 DPRINTF("Deps size has been copied (%d)", size);
 341
 342                 if (size == 0) {
 343                         DPRINTF("Deps are size of 0");
 344                         break;
 345                 }
 346
 347                 deps = vmalloc(size);
 348                 if (deps == NULL) {
 349                         EPRINTF("Cannot alloc mem for deps!");
 350                         result = -1;
 351                         break;
 352                 }
 353                 DPRINTF("Mem for deps has been allocated");
 354
 355                 result = copy_from_user(deps, (void *)arg, size);
 356                 if (result) {
 357                         EPRINTF("Cannot copy deps!");
 358                         result = -1;
 359                         break;
 360                 }
 361                 DPRINTF("Deps has been copied successfully");
 362
 363                 break;
 364         }
 365         case EC_IOCTL_SET_PID:
 366         {
 367                 unsigned int _pid;
 368
 369                 result = copy_from_user(&_pid, (void *)arg, sizeof(unsigned int));
 370                 if (result) {
 371                         EPRINTF("Cannot copy pid!");
 372                         result = -1;
 373                         break;
 374                 }
 375
 376                 inst_pid = _pid;
 377
 378                 DPRINTF("EC_IOCTL_SET_PID pid:%d", inst_pid);
 379
 380                 break;
 381         }
 382         case EC_IOCTL_SET_PROFILEBUNDLE:
 383         {
 384                 size_t size;
 385
 386                 result = copy_from_user(&size, (void *)arg, sizeof(size_t));
 387                 if (result) {
 388                         EPRINTF("Cannot copy bundle size!");
 389                         result = -1;
 390                         break;
 391                 }
 392                 DPRINTF("Bundle size has been copied");
 393
 394                 bundle = vmalloc(size);
 395                 if (bundle == NULL) {
 396                         EPRINTF("Cannot alloc mem for bundle!");
 397                         result = -1;
 398                         break;
 399                 }
 400                 DPRINTF("Mem for bundle has been alloced");
 401
 402                 result = copy_from_user(bundle, (void *)arg, size);
 403                 if (result) {
 404                         EPRINTF("Cannot copy bundle!");
 405                         result = -1;
 406                         break;
 407                 }
 408                 DPRINTF("Bundle has been copied successfully");
 409
 410                 if (link_bundle() == -1) {
 411                         EPRINTF("Cannot link profile bundle!");
 412                         result = -1;
 413                         break;
 414                 }
 415
 416                 break;
 417         }
 418         case EC_IOCTL_RESET_PROBES:
 419                 {
 420                         result = reset_probes();
 421
 422                         break;
 423                 }
 424         case EC_IOCTL_UPDATE_CONDS:
 425                 {
 426                         int args_cnt, i;
 427                         struct cond *c, *c_tmp, *p_cond;
 428                         unsigned char *p_data;
 429                         int err;
 430                         result = 0;
 431                         err = copy_from_user(&args_cnt, (void *)arg, sizeof(int));
 432                         if (err) {
 433                                 result = -1;
 434                                 break;
 435                         }
 436                         /* first, delete all the conds */
 437                         list_for_each_entry_safe(c, c_tmp, &cond_list.list, list) {
 438                                 list_del(&c->list);
 439                                 kfree(c);
 440                         }
 441                         /* second, add new conds */
 442                         p_data = (unsigned char *)(arg + sizeof(int));
 443                         for (i = 0; i < args_cnt; i++) {
 444                                 p_cond = kmalloc(sizeof(struct cond), GFP_KERNEL);
 445                                 if (!p_cond) {
 446                                         DPRINTF("Cannot alloc cond!");
 447                                         result = -1;
 448                                         break;
 449                                 }
 450                                 err = copy_from_user(&p_cond->tmpl, p_data, sizeof(struct event_tmpl));
 451                                 if (err) {
 452                                         DPRINTF("Cannot copy cond from user!");
 453                                         result = -1;
 454                                         break;
 455                                 }
 456                                 p_cond->applied = 0;
 457                                 list_add(&(p_cond->list), &(cond_list.list));
 458                                 p_data += sizeof(struct event_tmpl);
 459                         }
 460                         break;
 461                 }
 462         case EC_IOCTL_ATTACH:
 463                 {
 464                         unsigned long dbi_flags;
 465                         struct dbi_modules_handlers *local_mh;
 466                         struct dbi_modules_handlers_info *local_mhi;
 467                         int j;
 468                         dbi_module_callback dmc_start;
 469
 470                         // call "start"-callback for all modules according module priority
 471                         local_mh = get_dbi_modules_handlers();
 472                         spin_lock_irqsave(&local_mh->lock, dbi_flags);
 473                         for (j = 0; j <= MAX_PRIORITY; j++) {
 474                                 list_for_each_entry_rcu(local_mhi, &local_mh->modules_handlers, dbi_list_head) {
 475                                         if (local_mhi->dbi_module_priority_start == j) {
 476                                                 if (local_mhi->dbi_module_callback_start != NULL) {
 477                                                         printk("Started module callback (start) %s\n", local_mhi->dbi_module->name);
 478                                                         dmc_start = (dbi_module_callback )local_mhi->dbi_module_callback_start;
 479                                                         dmc_start();
 480                                                 }
 481                                         }
 482                                 }
 483                         }
 484                         spin_unlock_irqrestore(&local_mh->lock, dbi_flags);
 485
 486                         result = ec_user_attach ();
 487 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
 488                         DPRINTF("EC_IOCTL_ATTACH calling notification chain");
 489                         blocking_notifier_call_chain(&swap_notifier_list, EC_IOCTL_ATTACH, (void*)NULL);
 490 #endif
 491                         DPRINTF("Attach Probes");
 492                         break;
 493                 }
 494         case EC_IOCTL_ACTIVATE:
 495                 result = ec_user_activate ();
 496                 DPRINTF("Activate Probes");
 497                 break;
 498         case EC_IOCTL_STOP_AND_DETACH:
 499         {
 500                 unsigned long nIgnoredBytes = 0;
 501                 unsigned long dbi_flags;
 502                 struct dbi_modules_handlers *local_mh;
 503                 struct dbi_modules_handlers_info *local_mhi;
 504                 unsigned int local_module_refcount = 0;
 505                 int j;
 506                 dbi_module_callback dmc_stop;
 507
 508 #ifdef OVERHEAD_DEBUG
 509                 printk("\nswap_sum_time = %ld in kprobe_handler()\n", swap_sum_time);
 510                 printk("swap_sum_hit = %ld in kprobe_handler()\n", swap_sum_hit);
 511                 swap_sum_time = 0;
 512                 swap_sum_hit = 0;
 513 #endif
 514                 local_mh = get_dbi_modules_handlers();
 515                 if(ec_user_stop() != 0) {
 516                         result = -1;
 517                         goto sad_cleanup;
 518                 }
 519                 nIgnoredBytes = copy_ec_info_to_user_space ((ec_info_t*)arg);
 520                 if(nIgnoredBytes > 0) {
 521                         result = -1;
 522                         goto sad_cleanup;
 523                 }
 524                 vfree(bundle);
 525                 result = 0;
 526                 DPRINTF("Stop and Detach Probes");
 527 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
 528                 DPRINTF("EC_IOCTL_STOP_AND_DETACH calling notification chain");
 529                 blocking_notifier_call_chain(&swap_notifier_list, EC_IOCTL_STOP_AND_DETACH, (void*)&gl_nNotifyTgid);
 530 #endif
 531                 // call "stop"-callback for all modules according module priority
 532                 spin_lock_irqsave(&local_mh->lock, dbi_flags);
 533                 for (j = 0; j <= MAX_PRIORITY; j++) {
 534                         list_for_each_entry_rcu(local_mhi, &local_mh->modules_handlers, dbi_list_head) {
 535                                 if (local_mhi->dbi_module_priority_stop == j) {
 536                                         if (local_mhi->dbi_module_callback_stop != NULL) {
 537                                                 printk("Started module callback (stop) %s\n", local_mhi->dbi_module->name);
 538                                                 dmc_stop = (dbi_module_callback )local_mhi->dbi_module_callback_stop;
 539                                                 dmc_stop();
 540                                         }
 541                                 }
 542                         }
 543                 }
 544                 spin_unlock_irqrestore(&local_mh->lock, dbi_flags);
 545 sad_cleanup:
 546                 spin_lock_irqsave(&local_mh->lock, dbi_flags);
 547                 list_for_each_entry_rcu(local_mhi, &local_mh->modules_handlers, dbi_list_head) {
 548                         local_module_refcount = module_refcount(local_mhi->dbi_module);
 549                         if (local_module_refcount == 1) {
 550                                 module_put(local_mhi->dbi_module);
 551                         }
 552                         else if (local_module_refcount > 1) {
 553                                 printk("local_module_refcount too much - force set refcount to zero\n");
 554                                 while (local_module_refcount--)
 555                                         module_put(local_mhi->dbi_module);
 556                         }
 557                 }
 558                 spin_unlock_irqrestore(&local_mh->lock, dbi_flags);
 559                 break;
 560         }
 561         case EC_IOCTL_WAIT_NOTIFICATION:
 562                 {
 563                         static ec_info_t ec_info_copy;
 564
 565                         ioctl_wait_notification_t ioctl_args;
 566
 567                         result = copy_from_user (&ioctl_args, (void *) arg, sizeof (ioctl_args));
 568                         if (result)
 569                         {
 570                                 result = -1;
 571                                 break;
 572                         }
 573
 574                         result = wait_event_interruptible (notification_waiters_queue, ioctl_args.notification_count != notification_count);
 575                         if (result)
 576                         {
 577                                 result = -EINTR;        // woken by signal (ERESTARTSYS 512)
 578                                 break;
 579                         }
 580
 581                         ioctl_args.notification_count = notification_count;
 582
 583                         result = copy_to_user ((void *) arg, &ioctl_args, sizeof (ioctl_args));
 584                         if (result)
 585                         {
 586                                 result = -1;
 587                                 break;
 588                         }
 589
 590                         // FIXME: synchronization is necessary here (ec_info must be locked).
 591                         // ENTER_CRITICAL_SECTION
 592                         memcpy (&ec_info_copy, &ec_info, sizeof (ec_info_copy));
 593                         // LEAVE_CRITICAL_SECTION
 594
 595                         result = copy_to_user ((void *) ioctl_args.p_ec_info, &ec_info_copy, sizeof (ec_info_t));
 596                         if (result)
 597                         {
 598                                 EPRINTF ("copy_to_user(%08X,%08X)=%d", (unsigned) ioctl_args.p_ec_info, (unsigned) &ec_info_copy, result);
 599                                 result = -1;
 600                                 break;
 601                         }
 602                         DPRINTF("Wake up");
 603                         break;
 604                 }
 605         case EC_IOCTL_US_EVENT:
 606                 {
 607                         ioctl_us_event_t ioctl_args;
 608                         result = copy_from_user (&ioctl_args, (void *) arg, sizeof (ioctl_args));
 609                         if (result)
 610                         {
 611                                 result = -1;
 612                                 EPRINTF ("copy_from_user() failure");
 613                         }
 614                         else
 615                         {
 616                                 if(ioctl_args.len == 0){
 617                                         result = -EINVAL;
 618                                         EPRINTF ("invalid event length!");
 619                                 }
 620                                 else {
 621                                         char *buf = kmalloc(ioctl_args.len, GFP_KERNEL);
 622                                         if(!buf){
 623                                                 result = -ENOMEM;
 624                                                 EPRINTF ("failed to alloc mem for event!");
 625                                         }
 626                                         else {
 627                                                 result = copy_from_user (buf, (void *) ioctl_args.data, ioctl_args.len);
 628                                                 if (result){
 629                                                         result = -1;
 630                                                         EPRINTF ("failed to copy event from user space!");
 631                                                 }
 632                                                 else
 633                                                         result = put_us_event(buf, ioctl_args.len);
 634                                                 kfree(buf);
 635                                         }
 636                                 }
 637                         }
 638 //                      DPRINTF("User Space Event"); // Frequent call
 639                         break;
 640                 }
 641
 642         case EC_IOCTL_SET_EVENT_MASK:
 643                 {
 644                         int mask;
 645                         result = copy_from_user (&mask, (void *) arg, sizeof (mask));
 646                         if (result)
 647                         {
 648                                 result = -EFAULT;
 649                                 break;
 650                         }
 651
 652                         result = set_event_mask (mask);
 653                         if (result)
 654                         {
 655                                 break;
 656                         }
 657                         DPRINTF("Set Event Mask = %d", mask);
 658                         break;
 659                 }
 660
 661         case EC_IOCTL_GET_EVENT_MASK:
 662                 {
 663                         int mask = 0;
 664                         result = get_event_mask(&mask);
 665                         if (result)
 666                         {
 667                                 result = -EFAULT;
 668                         }
 669                         result = copy_to_user ((void *) arg, &mask, sizeof (mask));
 670                         if (result)
 671                         {
 672                                 result = -EFAULT;
 673                         }
 674                         DPRINTF("Get Event Mask = %d", mask);
 675                         break;
 676                 }
 677
 678         case EC_IOCTL_SET_PREDEF_UPROBES:
 679                 {
 680                         ioctl_predef_uprobes_info_t data;
 681                         result = copy_from_user (&data, (void *) arg, sizeof (data));
 682                         if (result)
 683                         {
 684                                 result = -EFAULT;
 685                                 break;
 686                         }
 687
 688                         result = set_predef_uprobes (&data);
 689                         if (result)
 690                         {
 691                                 break;
 692                         }
 693                         DPRINTF("Set Predefined User Space Probes");
 694                         break;
 695                 }
 696
 697         case EC_IOCTL_GET_PREDEF_UPROBES:
 698                 {
 699                         result = get_predef_uprobes((ioctl_predef_uprobes_info_t *)arg);
 700                         if (result)
 701                         {
 702                                 result = -EFAULT;
 703                         }
 704                         DPRINTF("Get Predefined User Space Probes");
 705                         break;
 706                 }
 707
 708         case EC_IOCTL_GET_PREDEF_UPROBES_SIZE:
 709                 {
 710                         int size = 0;
 711                         result = get_predef_uprobes_size(&size);
 712                         if (result)
 713                         {
 714                                 result = -EFAULT;
 715                         }
 716                         result = copy_to_user ((void *) arg, &size, sizeof (size));
 717                         if (result)
 718                         {
 719                                 result = -EFAULT;
 720                         }
 721                         DPRINTF("Get Size of Predefined User Space Probes");
 722                         break;
 723                 }
 724
 725         default:
 726                 EPRINTF ("Unknown driver command = %u", cmd);
 727                 result = -EINVAL;
 728                 break;
 729         }
 730
 731         return result;
 732 }