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 #include "sspt/sspt_procs.h"
  23
  24 #ifdef OVERHEAD_DEBUG
  25 extern unsigned long swap_sum_time;
  26 extern unsigned long swap_sum_hit;
  27 #endif
  28
  29
  30 extern unsigned long imi_sum_time;
  31 extern unsigned long imi_sum_hit;
  32
  33
  34 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
  35 static BLOCKING_NOTIFIER_HEAD(swap_notifier_list);
  36 #endif
  37 pid_t gl_nNotifyTgid;
  38 EXPORT_SYMBOL_GPL(gl_nNotifyTgid);
  39
  40 DECLARE_WAIT_QUEUE_HEAD (notification_waiters_queue);
  41 volatile unsigned notification_count;
  42
  43 static int device_mmap (struct file *filp, struct vm_area_struct *vma);
  44 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
  45 static int device_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg);
  46 #else
  47 static long device_ioctl (struct file *file, unsigned int cmd, unsigned long arg);
  48 #endif
  49 static int device_open(struct inode *, struct file *);
  50 static int device_release(struct inode *, struct file *);
  51 static ssize_t device_read(struct file *, char *, size_t, loff_t *);
  52 static ssize_t device_write(struct file *, const char *, size_t, loff_t *);
  53
  54 static int gl_nDeviceOpened = 0;
  55 static struct file_operations device_fops = {
  56         .owner = THIS_MODULE,
  57         .mmap = device_mmap,
  58 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
  59         .ioctl = device_ioctl,
  60 #else
  61         .unlocked_ioctl = device_ioctl,
  62 #endif
  63         .read = device_read,
  64         .write = device_write,
  65         .open = device_open,
  66         .release = device_release
  67 };
  68
  69 typedef void (* dbi_module_callback)();
  70
  71 int device_init (void)
  72 {
  73         int nReserved = 0;
  74         nReserved = register_chrdev(0, device_name, &device_fops);
  75         if(nReserved < 0)
  76         {
  77                 unregister_chrdev(nReserved, device_name);
  78                 EPRINTF("Cannot register character device!");
  79                 return -1;
  80         }
  81         EPRINTF("New device node with major number [%d], was created\n", nReserved);
  82         device_major = nReserved;
  83         return 0;
  84 }
  85
  86 void device_down (void)
  87 {
  88         unregister_chrdev(device_major, device_name);
  89 }
  90
  91 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
  92 void swap_register_notify (struct notifier_block *nb)
  93 {
  94         blocking_notifier_chain_register(&swap_notifier_list, nb);
  95 }
  96 EXPORT_SYMBOL_GPL(swap_register_notify);
  97
  98 void swap_unregister_notify (struct notifier_block *nb)
  99 {
 100         blocking_notifier_chain_unregister(&swap_notifier_list, nb);
 101 }
 102 EXPORT_SYMBOL_GPL(swap_unregister_notify);
 103 #endif
 104
 105 void notify_user (event_id_t event_id)
 106 {
 107         ec_info.events_counters[event_id] += 1;
 108
 109         if (EVENT_EC_PROBE_RECORD == event_id)
 110         {
 111                 // EC_PROBE_RECORD events happen to often. To reduce overhead user
 112                 // space will be notified only once per each EVENTS_AGGREGATION_USEC
 113                 static uint64_t timestamp_usec = 0;
 114
 115                 uint64_t current_usec;
 116                 uint64_t delta_usec;
 117
 118                 struct timeval tv;
 119
 120                 do_gettimeofday (&tv);
 121                 current_usec = 1000000ULL * (unsigned) tv.tv_sec + (unsigned) tv.tv_usec;
 122
 123                 if (current_usec < timestamp_usec)
 124                 {
 125                         // Note: time from do_gettimeofday() may go backward
 126                         EPRINTF ("current_usec=%llu timestamp_usec=%llu", current_usec, timestamp_usec);
 127                 }
 128                 else
 129                 {
 130                         delta_usec = current_usec - timestamp_usec;
 131                         if (EVENTS_AGGREGATION_USEC > delta_usec)
 132                         {
 133                                 // wait the time left
 134 #if defined(__DEBUG)
 135                                 unsigned UNUSED left_usec = EVENTS_AGGREGATION_USEC - delta_usec;
 136 #endif /* defined(__DEBUG) */
 137                                 return; // supress notification
 138                         }
 139                 }
 140                 timestamp_usec = current_usec;  // remember new time for the future use
 141         } else if (EVENT_EC_START_CONDITION_SEEN == event_id) {
 142                 return;         // supress notification
 143         } else if (EVENT_EC_STOP_CONDITION_SEEN == event_id) {
 144                 return;         // supress notification
 145         }
 146
 147         ++notification_count;
 148         wake_up_interruptible (&notification_waiters_queue);
 149 }
 150
 151 static int device_mmap (struct file *filp UNUSED, struct vm_area_struct *vma)
 152 {
 153         if(!p_buffer) {
 154                 EPRINTF("Null pointer to buffer!");
 155                 return -1;
 156         }
 157         return remap_vmalloc_range (vma, p_buffer, 0);
 158 }
 159
 160 static int device_open(struct inode *inode, struct file *file)
 161 {
 162         /*if (gl_nDeviceOpened)
 163                 return -EBUSY;*/
 164         gl_nDeviceOpened++;
 165         // TODO
 166         try_module_get(THIS_MODULE);
 167         return 0;
 168 }
 169
 170 static int device_release(struct inode *inode, struct file *file)
 171 {
 172         gl_nDeviceOpened--;
 173         module_put(THIS_MODULE);
 174         return 0;
 175 }
 176
 177 static ssize_t device_read(struct file *filp, char *buffer, size_t length, loff_t * offset)
 178 {
 179         EPRINTF("Operation <<read>> not supported!");
 180         return -1;
 181 }
 182
 183 static ssize_t device_write(struct file *filp, const char *buff, size_t len, loff_t * off)
 184 {
 185         EPRINTF("Operation <<write>> not supported!");
 186         return -1;
 187 }
 188
 189 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
 190 static int device_ioctl (struct inode *inode UNUSED, struct file *file UNUSED, unsigned int cmd, unsigned long arg)
 191 #else
 192 static long device_ioctl (struct file *file UNUSED, unsigned int cmd, unsigned long arg)
 193 #endif
 194 {
 195         unsigned long spinlock_flags = 0L;
 196         int result = -1;
 197 //      DPRINTF("Command=%d", cmd);
 198         switch (cmd)
 199         {
 200         case EC_IOCTL_SET_EC_MODE:
 201                 {
 202                         ioctl_general_t param;
 203                         unsigned long nIgnoredBytes = 0;
 204                         memset(&param, '0', sizeof(ioctl_general_t));
 205                         nIgnoredBytes = copy_from_user (&param, (void*)arg, sizeof(ioctl_general_t));
 206                         if (nIgnoredBytes > 0) {
 207                                 result = -1;
 208                                 break;
 209                         }
 210                         if(SetECMode(param.m_unsignedLong) == -1) {
 211                                 result = -1;
 212                                 break;
 213                         }
 214                         result = 0;
 215                         DPRINTF("Set EC Mode = %lu", param.m_unsignedLong);
 216                         break;
 217                 }
 218         case EC_IOCTL_GET_EC_MODE:
 219                 {
 220                         ioctl_general_t param;
 221                         unsigned long nIgnoredBytes = 0;
 222                         memset(&param, '0', sizeof(ioctl_general_t));
 223                         param.m_unsignedLong = GetECMode();
 224                         nIgnoredBytes = copy_to_user ((void*)arg, &param, sizeof (ioctl_general_t));
 225                         if (nIgnoredBytes > 0) {
 226                                 result = -1;
 227                                 break;
 228                         }
 229                         result = 0;
 230 //                      DPRINTF("Get EC Mode = %lu", param.m_unsignedLong);  // Frequent call
 231                         break;
 232                 }
 233         case EC_IOCTL_SET_BUFFER_SIZE:
 234                 {
 235                         ioctl_general_t param;
 236                         unsigned long nIgnoredBytes = 0;
 237                         memset(&param, '0', sizeof(ioctl_general_t));
 238                         nIgnoredBytes = copy_from_user (&param, (void*)arg, sizeof(ioctl_general_t));
 239                         if (nIgnoredBytes > 0) {
 240                                 result = -1;
 241                                 break;
 242                         }
 243                         if (SetBufferSize(param.m_unsignedLong) == -1) {
 244                                 result = -1;
 245                                 break;
 246                         }
 247                         result = 0;
 248                         DPRINTF("Set Buffer Size = %lu", param.m_unsignedLong);
 249                         break;
 250                 }
 251         case EC_IOCTL_GET_BUFFER_SIZE:
 252                 {
 253                         ioctl_general_t param;
 254                         unsigned long nIgnoredBytes = 0;
 255                         memset(&param, '0', sizeof(ioctl_general_t));
 256                         param.m_unsignedLong = GetBufferSize();
 257                         nIgnoredBytes = copy_to_user ((void*)arg, &param, sizeof (ioctl_general_t));
 258                         if (nIgnoredBytes > 0) {
 259                                 result = -1;
 260                                 break;
 261                         }
 262                         result = 0;
 263                         DPRINTF("Get Buffer Size = %lu", param.m_unsignedLong);
 264                         break;
 265                 }
 266         case EC_IOCTL_RESET_BUFFER:
 267                 {
 268                         if (ResetBuffer() == -1) {
 269                                 result = -1;
 270                                 break;
 271                         }
 272                         result = 0;
 273                         DPRINTF("Reset Buffer");
 274                         break;
 275                 }
 276         case EC_IOCTL_GET_EC_INFO:
 277                 {
 278                         if (copy_ec_info_to_user_space ((ec_info_t *) arg) != 0) {
 279                                 result = -1;
 280                                 break;
 281                         }
 282                         result = 0;
 283 //                      DPRINTF("Get Buffer Status"); // Frequent call
 284                         break;
 285                 }
 286         case EC_IOCTL_CONSUME_BUFFER:
 287                 {
 288                         static ec_info_t ec_info_copy;
 289                         int nIgnoredBytes = 0;
 290
 291                         nIgnoredBytes = copy_from_user (&ec_info_copy, (ec_info_t *) arg, sizeof (ec_info_t));
 292                         if(nIgnoredBytes > 0)
 293                         {
 294                                 EPRINTF ("copy_from_user(%08X,%08X)=%d", (unsigned) arg, (unsigned) &ec_info_copy, nIgnoredBytes);
 295                                 result = -1;
 296                                 break;
 297                         }
 298
 299                         spin_lock_irqsave (&ec_spinlock, spinlock_flags);
 300
 301                         // Original buffer
 302                         if(ec_info.after_last > ec_info.first) {
 303                                 ec_info.buffer_effect = ec_info.buffer_size;
 304                         }
 305                         if (ec_info.after_last == ec_info.buffer_effect) {
 306                                  ec_info.first = 0;
 307                         } else {
 308                                  ec_info.first = ec_info_copy.after_last;
 309                         }
 310                         ec_info.trace_size = ec_info.trace_size - ec_info_copy.trace_size;
 311
 312                         spin_unlock_irqrestore (&ec_spinlock, spinlock_flags);
 313                         result = 0;
 314 //                      DPRINTF("Consume Buffer"); // Frequent call
 315                         break;
 316                 }
 317         case EC_IOCTL_ADD_PROBE:
 318                 {
 319                         unsigned long addr = arg;
 320                         result = add_probe(addr);
 321
 322                         break;
 323                 }
 324         //@AGv: remove_probe expects probe address instead of name
 325         /*case EC_IOCTL_REMOVE_PROBE:
 326                 {
 327                         char *probe_name = (char *) arg;
 328                         result = remove_probe (probe_name);
 329
 330                         break;
 331                 }*/
 332         case EC_IOCTL_SET_APPDEPS:
 333         {
 334                 size_t size;
 335                 result = copy_from_user(&size, (void *)arg, sizeof(size_t));
 336                 if (result) {
 337                         EPRINTF("Cannot copy deps size!");
 338                         result = -1;
 339                         break;
 340                 }
 341                 DPRINTF("Deps size has been copied (%d)", size);
 342
 343                 if (size == 0) {
 344                         DPRINTF("Deps are size of 0");
 345                         break;
 346                 }
 347
 348                 deps = vmalloc(size);
 349                 if (deps == NULL) {
 350                         EPRINTF("Cannot alloc mem for deps!");
 351                         result = -1;
 352                         break;
 353                 }
 354                 DPRINTF("Mem for deps has been allocated");
 355
 356                 result = copy_from_user(deps, (void *)arg, size);
 357                 if (result) {
 358                         EPRINTF("Cannot copy deps!");
 359                         result = -1;
 360                         break;
 361                 }
 362                 DPRINTF("Deps has been copied successfully");
 363
 364                 break;
 365         }
 366         case EC_IOCTL_SET_PID:
 367         {
 368                 unsigned int _pid;
 369
 370                 result = copy_from_user(&_pid, (void *)arg, sizeof(unsigned int));
 371                 if (result) {
 372                         EPRINTF("Cannot copy pid!");
 373                         result = -1;
 374                         break;
 375                 }
 376
 377                 inst_pid = _pid;
 378
 379                 DPRINTF("EC_IOCTL_SET_PID pid:%d", inst_pid);
 380
 381                 break;
 382         }
 383         case EC_IOCTL_SET_PROFILEBUNDLE:
 384         {
 385                 size_t size;
 386
 387                 result = copy_from_user(&size, (void *)arg, sizeof(size_t));
 388                 if (result) {
 389                         EPRINTF("Cannot copy bundle size!");
 390                         result = -1;
 391                         break;
 392                 }
 393                 DPRINTF("Bundle size has been copied");
 394
 395                 bundle = vmalloc(size);
 396                 if (bundle == NULL) {
 397                         EPRINTF("Cannot alloc mem for bundle!");
 398                         result = -1;
 399                         break;
 400                 }
 401                 DPRINTF("Mem for bundle has been alloced");
 402
 403                 result = copy_from_user(bundle, (void *)arg, size);
 404                 if (result) {
 405                         EPRINTF("Cannot copy bundle!");
 406                         result = -1;
 407                         break;
 408                 }
 409                 DPRINTF("Bundle has been copied successfully");
 410
 411                 if (link_bundle() == -1) {
 412                         EPRINTF("Cannot link profile bundle!");
 413                         result = -1;
 414                         break;
 415                 }
 416
 417                 break;
 418         }
 419         case EC_IOCTL_RESET_PROBES:
 420                 {
 421                         result = reset_probes();
 422
 423                         break;
 424                 }
 425         case EC_IOCTL_UPDATE_CONDS:
 426                 {
 427                         int args_cnt, i;
 428                         struct cond *c, *c_tmp, *p_cond;
 429                         unsigned char *p_data;
 430                         int err;
 431                         result = 0;
 432                         err = copy_from_user(&args_cnt, (void *)arg, sizeof(int));
 433                         if (err) {
 434                                 result = -1;
 435                                 break;
 436                         }
 437                         /* first, delete all the conds */
 438                         list_for_each_entry_safe(c, c_tmp, &cond_list.list, list) {
 439                                 list_del(&c->list);
 440                                 kfree(c);
 441                         }
 442                         /* second, add new conds */
 443                         p_data = (unsigned char *)(arg + sizeof(int));
 444                         for (i = 0; i < args_cnt; i++) {
 445                                 p_cond = kmalloc(sizeof(struct cond), GFP_KERNEL);
 446                                 if (!p_cond) {
 447                                         DPRINTF("Cannot alloc cond!");
 448                                         result = -1;
 449                                         break;
 450                                 }
 451                                 err = copy_from_user(&p_cond->tmpl, p_data, sizeof(struct event_tmpl));
 452                                 if (err) {
 453                                         DPRINTF("Cannot copy cond from user!");
 454                                         result = -1;
 455                                         break;
 456                                 }
 457                                 p_cond->applied = 0;
 458                                 list_add(&(p_cond->list), &(cond_list.list));
 459                                 p_data += sizeof(struct event_tmpl);
 460                         }
 461                         break;
 462                 }
 463         case EC_IOCTL_ATTACH:
 464                 {
 465                         unsigned long dbi_flags;
 466                         struct dbi_modules_handlers *local_mh;
 467                         struct dbi_modules_handlers_info *local_mhi;
 468                         int j;
 469                         dbi_module_callback dmc_start;
 470
 471                         // call "start"-callback for all modules according module priority
 472                         local_mh = get_dbi_modules_handlers();
 473                         spin_lock_irqsave(&local_mh->lock, dbi_flags);
 474                         for (j = 0; j <= MAX_PRIORITY; j++) {
 475                                 list_for_each_entry_rcu(local_mhi, &local_mh->modules_handlers, dbi_list_head) {
 476                                         if (local_mhi->dbi_module_priority_start == j) {
 477                                                 if (local_mhi->dbi_module_callback_start != NULL) {
 478                                                         printk("Started module callback (start) %s\n", local_mhi->dbi_module->name);
 479                                                         dmc_start = (dbi_module_callback )local_mhi->dbi_module_callback_start;
 480                                                         dmc_start();
 481                                                 }
 482                                         }
 483                                 }
 484                         }
 485                         spin_unlock_irqrestore(&local_mh->lock, dbi_flags);
 486
 487                         result = ec_user_attach ();
 488 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
 489                         DPRINTF("EC_IOCTL_ATTACH calling notification chain");
 490                         blocking_notifier_call_chain(&swap_notifier_list, EC_IOCTL_ATTACH, (void*)NULL);
 491 #endif
 492                         DPRINTF("Attach Probes");
 493                         break;
 494                 }
 495         case EC_IOCTL_ACTIVATE:
 496                 result = ec_user_activate ();
 497                 DPRINTF("Activate Probes");
 498                 break;
 499         case EC_IOCTL_STOP_AND_DETACH:
 500         {
 501                 unsigned long nIgnoredBytes = 0;
 502                 unsigned long dbi_flags;
 503                 struct dbi_modules_handlers *local_mh;
 504                 struct dbi_modules_handlers_info *local_mhi;
 505                 unsigned int local_module_refcount = 0;
 506                 int j;
 507                 dbi_module_callback dmc_stop;
 508
 509 #ifdef OVERHEAD_DEBUG
 510                 printk("\nswap_sum_time = %ld in kprobe_handler()\n", swap_sum_time);
 511                 printk("swap_sum_hit = %ld in kprobe_handler()\n", swap_sum_hit);
 512                 swap_sum_time = 0;
 513                 swap_sum_hit = 0;
 514 #endif
 515
 516                 printk("\n### imi_sum_time = %ld in install_mapped_ips()\n", imi_sum_time);
 517                 printk("### imi_sum_hit = %ld in install_mapped_ips()\n", imi_sum_hit);
 518
 519                 if (imi_sum_hit != 0) {
 520                         printk("### time = %ld in install_mapped_ips()\n", imi_sum_time/imi_sum_hit);
 521                 }
 522
 523                 imi_sum_time = 0;
 524                 imi_sum_hit = 0;
 525
 526                 local_mh = get_dbi_modules_handlers();
 527                 if(ec_user_stop() != 0) {
 528                         result = -1;
 529                         goto sad_cleanup;
 530                 }
 531                 nIgnoredBytes = copy_ec_info_to_user_space ((ec_info_t*)arg);
 532                 if(nIgnoredBytes > 0) {
 533                         result = -1;
 534                         goto sad_cleanup;
 535                 }
 536
 537                 sspt_procs_free_all();
 538
 539                 vfree(bundle);
 540                 result = 0;
 541                 DPRINTF("Stop and Detach Probes");
 542 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 17)
 543                 DPRINTF("EC_IOCTL_STOP_AND_DETACH calling notification chain");
 544                 blocking_notifier_call_chain(&swap_notifier_list, EC_IOCTL_STOP_AND_DETACH, (void*)&gl_nNotifyTgid);
 545 #endif
 546                 // call "stop"-callback for all modules according module priority
 547                 spin_lock_irqsave(&local_mh->lock, dbi_flags);
 548                 for (j = 0; j <= MAX_PRIORITY; j++) {
 549                         list_for_each_entry_rcu(local_mhi, &local_mh->modules_handlers, dbi_list_head) {
 550                                 if (local_mhi->dbi_module_priority_stop == j) {
 551                                         if (local_mhi->dbi_module_callback_stop != NULL) {
 552                                                 printk("Started module callback (stop) %s\n", local_mhi->dbi_module->name);
 553                                                 dmc_stop = (dbi_module_callback )local_mhi->dbi_module_callback_stop;
 554                                                 dmc_stop();
 555                                         }
 556                                 }
 557                         }
 558                 }
 559                 spin_unlock_irqrestore(&local_mh->lock, dbi_flags);
 560 sad_cleanup:
 561                 spin_lock_irqsave(&local_mh->lock, dbi_flags);
 562                 list_for_each_entry_rcu(local_mhi, &local_mh->modules_handlers, dbi_list_head) {
 563                         local_module_refcount = module_refcount(local_mhi->dbi_module);
 564                         if (local_module_refcount == 1) {
 565                                 module_put(local_mhi->dbi_module);
 566                         }
 567                         else if (local_module_refcount > 1) {
 568                                 printk("local_module_refcount too much - force set refcount to zero\n");
 569                                 while (local_module_refcount--)
 570                                         module_put(local_mhi->dbi_module);
 571                         }
 572                 }
 573                 spin_unlock_irqrestore(&local_mh->lock, dbi_flags);
 574                 break;
 575         }
 576         case EC_IOCTL_WAIT_NOTIFICATION:
 577                 {
 578                         static ec_info_t ec_info_copy;
 579
 580                         ioctl_wait_notification_t ioctl_args;
 581
 582                         result = copy_from_user (&ioctl_args, (void *) arg, sizeof (ioctl_args));
 583                         if (result)
 584                         {
 585                                 result = -1;
 586                                 break;
 587                         }
 588
 589                         result = wait_event_interruptible (notification_waiters_queue, ioctl_args.notification_count != notification_count);
 590                         if (result)
 591                         {
 592                                 result = -EINTR;        // woken by signal (ERESTARTSYS 512)
 593                                 break;
 594                         }
 595
 596                         ioctl_args.notification_count = notification_count;
 597
 598                         result = copy_to_user ((void *) arg, &ioctl_args, sizeof (ioctl_args));
 599                         if (result)
 600                         {
 601                                 result = -1;
 602                                 break;
 603                         }
 604
 605                         // FIXME: synchronization is necessary here (ec_info must be locked).
 606                         // ENTER_CRITICAL_SECTION
 607                         memcpy (&ec_info_copy, &ec_info, sizeof (ec_info_copy));
 608                         // LEAVE_CRITICAL_SECTION
 609
 610                         result = copy_to_user ((void *) ioctl_args.p_ec_info, &ec_info_copy, sizeof (ec_info_t));
 611                         if (result)
 612                         {
 613                                 EPRINTF ("copy_to_user(%08X,%08X)=%d", (unsigned) ioctl_args.p_ec_info, (unsigned) &ec_info_copy, result);
 614                                 result = -1;
 615                                 break;
 616                         }
 617                         DPRINTF("Wake up");
 618                         break;
 619                 }
 620         case EC_IOCTL_US_EVENT:
 621                 {
 622                         ioctl_us_event_t ioctl_args;
 623                         result = copy_from_user (&ioctl_args, (void *) arg, sizeof (ioctl_args));
 624                         if (result)
 625                         {
 626                                 result = -1;
 627                                 EPRINTF ("copy_from_user() failure");
 628                         }
 629                         else
 630                         {
 631                                 if(ioctl_args.len == 0){
 632                                         result = -EINVAL;
 633                                         EPRINTF ("invalid event length!");
 634                                 }
 635                                 else {
 636                                         char *buf = kmalloc(ioctl_args.len, GFP_KERNEL);
 637                                         if(!buf){
 638                                                 result = -ENOMEM;
 639                                                 EPRINTF ("failed to alloc mem for event!");
 640                                         }
 641                                         else {
 642                                                 result = copy_from_user (buf, (void *) ioctl_args.data, ioctl_args.len);
 643                                                 if (result){
 644                                                         result = -1;
 645                                                         EPRINTF ("failed to copy event from user space!");
 646                                                 }
 647                                                 else
 648                                                         result = put_us_event(buf, ioctl_args.len);
 649                                                 kfree(buf);
 650                                         }
 651                                 }
 652                         }
 653 //                      DPRINTF("User Space Event"); // Frequent call
 654                         break;
 655                 }
 656
 657         case EC_IOCTL_SET_EVENT_MASK:
 658                 {
 659                         int mask;
 660                         result = copy_from_user (&mask, (void *) arg, sizeof (mask));
 661                         if (result)
 662                         {
 663                                 result = -EFAULT;
 664                                 break;
 665                         }
 666
 667                         result = set_event_mask (mask);
 668                         if (result)
 669                         {
 670                                 break;
 671                         }
 672                         DPRINTF("Set Event Mask = %d", mask);
 673                         break;
 674                 }
 675
 676         case EC_IOCTL_GET_EVENT_MASK:
 677                 {
 678                         int mask = 0;
 679                         result = get_event_mask(&mask);
 680                         if (result)
 681                         {
 682                                 result = -EFAULT;
 683                         }
 684                         result = copy_to_user ((void *) arg, &mask, sizeof (mask));
 685                         if (result)
 686                         {
 687                                 result = -EFAULT;
 688                         }
 689                         DPRINTF("Get Event Mask = %d", mask);
 690                         break;
 691                 }
 692
 693         case EC_IOCTL_SET_PREDEF_UPROBES:
 694                 {
 695                         result = -1;
 696                         break;
 697
 698                         ioctl_predef_uprobes_info_t data;
 699                         result = copy_from_user (&data, (void *) arg, sizeof (data));
 700                         if (result)
 701                         {
 702                                 result = -EFAULT;
 703                                 break;
 704                         }
 705
 706                         result = set_predef_uprobes (&data);
 707                         if (result)
 708                         {
 709                                 break;
 710                         }
 711                         DPRINTF("Set Predefined User Space Probes");
 712                         break;
 713                 }
 714
 715         case EC_IOCTL_GET_PREDEF_UPROBES:
 716                 {
 717 //                      result = 0;
 718 //                      break;
 719
 720                         result = get_predef_uprobes((ioctl_predef_uprobes_info_t *)arg);
 721                         if (result)
 722                         {
 723                                 result = -EFAULT;
 724                         }
 725                         DPRINTF("Get Predefined User Space Probes");
 726                         break;
 727                 }
 728
 729         case EC_IOCTL_GET_PREDEF_UPROBES_SIZE:
 730                 {
 731                         int size = 0;
 732                         result = get_predef_uprobes_size(&size);
 733                         if (result)
 734                         {
 735                                 result = -EFAULT;
 736                         }
 737                         result = copy_to_user ((void *) arg, &size, sizeof (size));
 738                         if (result)
 739                         {
 740                                 result = -EFAULT;
 741                         }
 742                         DPRINTF("Get Size of Predefined User Space Probes");
 743                         break;
 744                 }
 745
 746         default:
 747                 EPRINTF ("Unknown driver command = %u", cmd);
 748                 result = -EINVAL;
 749                 break;
 750         }
 751
 752         return result;
 753 }