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   1 /*
   2  *  arch/s390/kernel/debug.c
   3  *   S/390 debug facility
   4  *
   5  *    Copyright (C) 1999, 2000 IBM Deutschland Entwicklung GmbH,
   6  *                             IBM Corporation
   7  *    Author(s): Michael Holzheu (holzheu@de.ibm.com),
   8  *               Holger Smolinski (Holger.Smolinski@de.ibm.com)
   9  *
  10  *    Bugreports to: <Linux390@de.ibm.com>
  11  */
  12
  13 #define KMSG_COMPONENT "s390dbf"
  14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  15
  16 #include <linux/stddef.h>
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/slab.h>
  20 #include <linux/ctype.h>
  21 #include <linux/sysctl.h>
  22 #include <asm/uaccess.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/fs.h>
  26 #include <linux/debugfs.h>
  27
  28 #include <asm/debug.h>
  29
  30 #define DEBUG_PROLOG_ENTRY -1
  31
  32 #define ALL_AREAS 0 /* copy all debug areas */
  33 #define NO_AREAS  1 /* copy no debug areas */
  34
  35 /* typedefs */
  36
  37 typedef struct file_private_info {
  38         loff_t offset;                  /* offset of last read in file */
  39         int    act_area;                /* number of last formated area */
  40         int    act_page;                /* act page in given area */
  41         int    act_entry;               /* last formated entry (offset */
  42                                         /* relative to beginning of last */
  43                                         /* formated page) */
  44         size_t act_entry_offset;        /* up to this offset we copied */
  45                                         /* in last read the last formated */
  46                                         /* entry to userland */
  47         char   temp_buf[2048];          /* buffer for output */
  48         debug_info_t *debug_info_org;   /* original debug information */
  49         debug_info_t *debug_info_snap;  /* snapshot of debug information */
  50         struct debug_view *view;        /* used view of debug info */
  51 } file_private_info_t;
  52
  53 typedef struct
  54 {
  55         char *string;
  56         /*
  57          * This assumes that all args are converted into longs
  58          * on L/390 this is the case for all types of parameter
  59          * except of floats, and long long (32 bit)
  60          *
  61          */
  62         long args[0];
  63 } debug_sprintf_entry_t;
  64
  65
  66 extern void tod_to_timeval(uint64_t todval, struct timespec *xtime);
  67
  68 /* internal function prototyes */
  69
  70 static int debug_init(void);
  71 static ssize_t debug_output(struct file *file, char __user *user_buf,
  72                         size_t user_len, loff_t * offset);
  73 static ssize_t debug_input(struct file *file, const char __user *user_buf,
  74                         size_t user_len, loff_t * offset);
  75 static int debug_open(struct inode *inode, struct file *file);
  76 static int debug_close(struct inode *inode, struct file *file);
  77 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
  78                         int nr_areas, int buf_size, mode_t mode);
  79 static void debug_info_get(debug_info_t *);
  80 static void debug_info_put(debug_info_t *);
  81 static int debug_prolog_level_fn(debug_info_t * id,
  82                         struct debug_view *view, char *out_buf);
  83 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
  84                         struct file *file, const char __user *user_buf,
  85                         size_t user_buf_size, loff_t * offset);
  86 static int debug_prolog_pages_fn(debug_info_t * id,
  87                         struct debug_view *view, char *out_buf);
  88 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
  89                         struct file *file, const char __user *user_buf,
  90                         size_t user_buf_size, loff_t * offset);
  91 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
  92                         struct file *file, const char __user *user_buf,
  93                         size_t user_buf_size, loff_t * offset);
  94 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
  95                         char *out_buf, const char *in_buf);
  96 static int debug_raw_format_fn(debug_info_t * id,
  97                         struct debug_view *view, char *out_buf,
  98                         const char *in_buf);
  99 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
 100                         int area, debug_entry_t * entry, char *out_buf);
 101
 102 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
 103                         char *out_buf, debug_sprintf_entry_t *curr_event);
 104
 105 /* globals */
 106
 107 struct debug_view debug_raw_view = {
 108         "raw",
 109         NULL,
 110         &debug_raw_header_fn,
 111         &debug_raw_format_fn,
 112         NULL,
 113         NULL
 114 };
 115
 116 struct debug_view debug_hex_ascii_view = {
 117         "hex_ascii",
 118         NULL,
 119         &debug_dflt_header_fn,
 120         &debug_hex_ascii_format_fn,
 121         NULL,
 122         NULL
 123 };
 124
 125 static struct debug_view debug_level_view = {
 126         "level",
 127         &debug_prolog_level_fn,
 128         NULL,
 129         NULL,
 130         &debug_input_level_fn,
 131         NULL
 132 };
 133
 134 static struct debug_view debug_pages_view = {
 135         "pages",
 136         &debug_prolog_pages_fn,
 137         NULL,
 138         NULL,
 139         &debug_input_pages_fn,
 140         NULL
 141 };
 142
 143 static struct debug_view debug_flush_view = {
 144         "flush",
 145         NULL,
 146         NULL,
 147         NULL,
 148         &debug_input_flush_fn,
 149         NULL
 150 };
 151
 152 struct debug_view debug_sprintf_view = {
 153         "sprintf",
 154         NULL,
 155         &debug_dflt_header_fn,
 156         (debug_format_proc_t*)&debug_sprintf_format_fn,
 157         NULL,
 158         NULL
 159 };
 160
 161 /* used by dump analysis tools to determine version of debug feature */
 162 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
 163
 164 /* static globals */
 165
 166 static debug_info_t *debug_area_first = NULL;
 167 static debug_info_t *debug_area_last = NULL;
 168 static DEFINE_MUTEX(debug_mutex);
 169
 170 static int initialized;
 171
 172 static const struct file_operations debug_file_ops = {
 173         .owner   = THIS_MODULE,
 174         .read    = debug_output,
 175         .write   = debug_input,
 176         .open    = debug_open,
 177         .release = debug_close,
 178 };
 179
 180 static struct dentry *debug_debugfs_root_entry;
 181
 182 /* functions */
 183
 184 /*
 185  * debug_areas_alloc
 186  * - Debug areas are implemented as a threedimensonal array:
 187  *   areas[areanumber][pagenumber][pageoffset]
 188  */
 189
 190 static debug_entry_t***
 191 debug_areas_alloc(int pages_per_area, int nr_areas)
 192 {
 193         debug_entry_t*** areas;
 194         int i,j;
 195
 196         areas = kmalloc(nr_areas *
 197                                         sizeof(debug_entry_t**),
 198                                         GFP_KERNEL);
 199         if (!areas)
 200                 goto fail_malloc_areas;
 201         for (i = 0; i < nr_areas; i++) {
 202                 areas[i] = kmalloc(pages_per_area *
 203                                 sizeof(debug_entry_t*),GFP_KERNEL);
 204                 if (!areas[i]) {
 205                         goto fail_malloc_areas2;
 206                 }
 207                 for(j = 0; j < pages_per_area; j++) {
 208                         areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
 209                         if(!areas[i][j]) {
 210                                 for(j--; j >=0 ; j--) {
 211                                         kfree(areas[i][j]);
 212                                 }
 213                                 kfree(areas[i]);
 214                                 goto fail_malloc_areas2;
 215                         }
 216                 }
 217         }
 218         return areas;
 219
 220 fail_malloc_areas2:
 221         for(i--; i >= 0; i--){
 222                 for(j=0; j < pages_per_area;j++){
 223                         kfree(areas[i][j]);
 224                 }
 225                 kfree(areas[i]);
 226         }
 227         kfree(areas);
 228 fail_malloc_areas:
 229         return NULL;
 230
 231 }
 232
 233
 234 /*
 235  * debug_info_alloc
 236  * - alloc new debug-info
 237  */
 238
 239 static debug_info_t*
 240 debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
 241                  int buf_size, int level, int mode)
 242 {
 243         debug_info_t* rc;
 244
 245         /* alloc everything */
 246
 247         rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
 248         if(!rc)
 249                 goto fail_malloc_rc;
 250         rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
 251         if(!rc->active_entries)
 252                 goto fail_malloc_active_entries;
 253         rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
 254         if(!rc->active_pages)
 255                 goto fail_malloc_active_pages;
 256         if((mode == ALL_AREAS) && (pages_per_area != 0)){
 257                 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
 258                 if(!rc->areas)
 259                         goto fail_malloc_areas;
 260         } else {
 261                 rc->areas = NULL;
 262         }
 263
 264         /* initialize members */
 265
 266         spin_lock_init(&rc->lock);
 267         rc->pages_per_area = pages_per_area;
 268         rc->nr_areas       = nr_areas;
 269         rc->active_area    = 0;
 270         rc->level          = level;
 271         rc->buf_size       = buf_size;
 272         rc->entry_size     = sizeof(debug_entry_t) + buf_size;
 273         strlcpy(rc->name, name, sizeof(rc->name));
 274         memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
 275         memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
 276                 sizeof(struct dentry*));
 277         atomic_set(&(rc->ref_count), 0);
 278
 279         return rc;
 280
 281 fail_malloc_areas:
 282         kfree(rc->active_pages);
 283 fail_malloc_active_pages:
 284         kfree(rc->active_entries);
 285 fail_malloc_active_entries:
 286         kfree(rc);
 287 fail_malloc_rc:
 288         return NULL;
 289 }
 290
 291 /*
 292  * debug_areas_free
 293  * - free all debug areas
 294  */
 295
 296 static void
 297 debug_areas_free(debug_info_t* db_info)
 298 {
 299         int i,j;
 300
 301         if(!db_info->areas)
 302                 return;
 303         for (i = 0; i < db_info->nr_areas; i++) {
 304                 for(j = 0; j < db_info->pages_per_area; j++) {
 305                         kfree(db_info->areas[i][j]);
 306                 }
 307                 kfree(db_info->areas[i]);
 308         }
 309         kfree(db_info->areas);
 310         db_info->areas = NULL;
 311 }
 312
 313 /*
 314  * debug_info_free
 315  * - free memory debug-info
 316  */
 317
 318 static void
 319 debug_info_free(debug_info_t* db_info){
 320         debug_areas_free(db_info);
 321         kfree(db_info->active_entries);
 322         kfree(db_info->active_pages);
 323         kfree(db_info);
 324 }
 325
 326 /*
 327  * debug_info_create
 328  * - create new debug-info
 329  */
 330
 331 static debug_info_t*
 332 debug_info_create(const char *name, int pages_per_area, int nr_areas,
 333                   int buf_size, mode_t mode)
 334 {
 335         debug_info_t* rc;
 336
 337         rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
 338                                 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
 339         if(!rc)
 340                 goto out;
 341
 342         rc->mode = mode & ~S_IFMT;
 343
 344         /* create root directory */
 345         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
 346                                         debug_debugfs_root_entry);
 347
 348         /* append new element to linked list */
 349         if (!debug_area_first) {
 350                 /* first element in list */
 351                 debug_area_first = rc;
 352                 rc->prev = NULL;
 353         } else {
 354                 /* append element to end of list */
 355                 debug_area_last->next = rc;
 356                 rc->prev = debug_area_last;
 357         }
 358         debug_area_last = rc;
 359         rc->next = NULL;
 360
 361         debug_info_get(rc);
 362 out:
 363         return rc;
 364 }
 365
 366 /*
 367  * debug_info_copy
 368  * - copy debug-info
 369  */
 370
 371 static debug_info_t*
 372 debug_info_copy(debug_info_t* in, int mode)
 373 {
 374         int i,j;
 375         debug_info_t* rc;
 376         unsigned long flags;
 377
 378         /* get a consistent copy of the debug areas */
 379         do {
 380                 rc = debug_info_alloc(in->name, in->pages_per_area,
 381                         in->nr_areas, in->buf_size, in->level, mode);
 382                 spin_lock_irqsave(&in->lock, flags);
 383                 if(!rc)
 384                         goto out;
 385                 /* has something changed in the meantime ? */
 386                 if((rc->pages_per_area == in->pages_per_area) &&
 387                    (rc->nr_areas == in->nr_areas)) {
 388                         break;
 389                 }
 390                 spin_unlock_irqrestore(&in->lock, flags);
 391                 debug_info_free(rc);
 392         } while (1);
 393
 394         if (mode == NO_AREAS)
 395                 goto out;
 396
 397         for(i = 0; i < in->nr_areas; i++){
 398                 for(j = 0; j < in->pages_per_area; j++) {
 399                         memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
 400                 }
 401         }
 402 out:
 403         spin_unlock_irqrestore(&in->lock, flags);
 404         return rc;
 405 }
 406
 407 /*
 408  * debug_info_get
 409  * - increments reference count for debug-info
 410  */
 411
 412 static void
 413 debug_info_get(debug_info_t * db_info)
 414 {
 415         if (db_info)
 416                 atomic_inc(&db_info->ref_count);
 417 }
 418
 419 /*
 420  * debug_info_put:
 421  * - decreases reference count for debug-info and frees it if necessary
 422  */
 423
 424 static void
 425 debug_info_put(debug_info_t *db_info)
 426 {
 427         int i;
 428
 429         if (!db_info)
 430                 return;
 431         if (atomic_dec_and_test(&db_info->ref_count)) {
 432                 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
 433                         if (!db_info->views[i])
 434                                 continue;
 435                         debugfs_remove(db_info->debugfs_entries[i]);
 436                 }
 437                 debugfs_remove(db_info->debugfs_root_entry);
 438                 if(db_info == debug_area_first)
 439                         debug_area_first = db_info->next;
 440                 if(db_info == debug_area_last)
 441                         debug_area_last = db_info->prev;
 442                 if(db_info->prev) db_info->prev->next = db_info->next;
 443                 if(db_info->next) db_info->next->prev = db_info->prev;
 444                 debug_info_free(db_info);
 445         }
 446 }
 447
 448 /*
 449  * debug_format_entry:
 450  * - format one debug entry and return size of formated data
 451  */
 452
 453 static int
 454 debug_format_entry(file_private_info_t *p_info)
 455 {
 456         debug_info_t *id_snap   = p_info->debug_info_snap;
 457         struct debug_view *view = p_info->view;
 458         debug_entry_t *act_entry;
 459         size_t len = 0;
 460         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
 461                 /* print prolog */
 462                 if (view->prolog_proc)
 463                         len += view->prolog_proc(id_snap,view,p_info->temp_buf);
 464                 goto out;
 465         }
 466         if (!id_snap->areas) /* this is true, if we have a prolog only view */
 467                 goto out;    /* or if 'pages_per_area' is 0 */
 468         act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
 469                                 [p_info->act_page] + p_info->act_entry);
 470
 471         if (act_entry->id.stck == 0LL)
 472                         goto out;  /* empty entry */
 473         if (view->header_proc)
 474                 len += view->header_proc(id_snap, view, p_info->act_area,
 475                                         act_entry, p_info->temp_buf + len);
 476         if (view->format_proc)
 477                 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
 478                                                 DEBUG_DATA(act_entry));
 479 out:
 480         return len;
 481 }
 482
 483 /*
 484  * debug_next_entry:
 485  * - goto next entry in p_info
 486  */
 487
 488 static inline int
 489 debug_next_entry(file_private_info_t *p_info)
 490 {
 491         debug_info_t *id;
 492
 493         id = p_info->debug_info_snap;
 494         if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
 495                 p_info->act_entry = 0;
 496                 p_info->act_page  = 0;
 497                 goto out;
 498         }
 499         if(!id->areas)
 500                 return 1;
 501         p_info->act_entry += id->entry_size;
 502         /* switch to next page, if we reached the end of the page  */
 503         if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
 504                 /* next page */
 505                 p_info->act_entry = 0;
 506                 p_info->act_page += 1;
 507                 if((p_info->act_page % id->pages_per_area) == 0) {
 508                         /* next area */
 509                         p_info->act_area++;
 510                         p_info->act_page=0;
 511                 }
 512                 if(p_info->act_area >= id->nr_areas)
 513                         return 1;
 514         }
 515 out:
 516         return 0;
 517 }
 518
 519 /*
 520  * debug_output:
 521  * - called for user read()
 522  * - copies formated debug entries to the user buffer
 523  */
 524
 525 static ssize_t
 526 debug_output(struct file *file,         /* file descriptor */
 527             char __user *user_buf,      /* user buffer */
 528             size_t  len,                /* length of buffer */
 529             loff_t *offset)             /* offset in the file */
 530 {
 531         size_t count = 0;
 532         size_t entry_offset;
 533         file_private_info_t *p_info;
 534
 535         p_info = ((file_private_info_t *) file->private_data);
 536         if (*offset != p_info->offset)
 537                 return -EPIPE;
 538         if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
 539                 return 0;
 540         entry_offset = p_info->act_entry_offset;
 541         while(count < len){
 542                 int formatted_line_size;
 543                 int formatted_line_residue;
 544                 int user_buf_residue;
 545                 size_t copy_size;
 546
 547                 formatted_line_size = debug_format_entry(p_info);
 548                 formatted_line_residue = formatted_line_size - entry_offset;
 549                 user_buf_residue = len-count;
 550                 copy_size = min(user_buf_residue, formatted_line_residue);
 551                 if(copy_size){
 552                         if (copy_to_user(user_buf + count, p_info->temp_buf
 553                                         + entry_offset, copy_size))
 554                                 return -EFAULT;
 555                         count += copy_size;
 556                         entry_offset += copy_size;
 557                 }
 558                 if(copy_size == formatted_line_residue){
 559                         entry_offset = 0;
 560                         if(debug_next_entry(p_info))
 561                                 goto out;
 562                 }
 563         }
 564 out:
 565         p_info->offset           = *offset + count;
 566         p_info->act_entry_offset = entry_offset;
 567         *offset = p_info->offset;
 568         return count;
 569 }
 570
 571 /*
 572  * debug_input:
 573  * - called for user write()
 574  * - calls input function of view
 575  */
 576
 577 static ssize_t
 578 debug_input(struct file *file, const char __user *user_buf, size_t length,
 579                 loff_t *offset)
 580 {
 581         int rc = 0;
 582         file_private_info_t *p_info;
 583
 584         mutex_lock(&debug_mutex);
 585         p_info = ((file_private_info_t *) file->private_data);
 586         if (p_info->view->input_proc)
 587                 rc = p_info->view->input_proc(p_info->debug_info_org,
 588                                               p_info->view, file, user_buf,
 589                                               length, offset);
 590         else
 591                 rc = -EPERM;
 592         mutex_unlock(&debug_mutex);
 593         return rc;              /* number of input characters */
 594 }
 595
 596 /*
 597  * debug_open:
 598  * - called for user open()
 599  * - copies formated output to private_data area of the file
 600  *   handle
 601  */
 602
 603 static int
 604 debug_open(struct inode *inode, struct file *file)
 605 {
 606         int i = 0, rc = 0;
 607         file_private_info_t *p_info;
 608         debug_info_t *debug_info, *debug_info_snapshot;
 609
 610         mutex_lock(&debug_mutex);
 611         debug_info = file->f_path.dentry->d_inode->i_private;
 612         /* find debug view */
 613         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
 614                 if (!debug_info->views[i])
 615                         continue;
 616                 else if (debug_info->debugfs_entries[i] ==
 617                          file->f_path.dentry) {
 618                         goto found;     /* found view ! */
 619                 }
 620         }
 621         /* no entry found */
 622         rc = -EINVAL;
 623         goto out;
 624
 625 found:
 626
 627         /* Make snapshot of current debug areas to get it consistent.     */
 628         /* To copy all the areas is only needed, if we have a view which  */
 629         /* formats the debug areas. */
 630
 631         if(!debug_info->views[i]->format_proc &&
 632                 !debug_info->views[i]->header_proc){
 633                 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
 634         } else {
 635                 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
 636         }
 637
 638         if(!debug_info_snapshot){
 639                 rc = -ENOMEM;
 640                 goto out;
 641         }
 642         p_info = kmalloc(sizeof(file_private_info_t),
 643                                                 GFP_KERNEL);
 644         if(!p_info){
 645                 if(debug_info_snapshot)
 646                         debug_info_free(debug_info_snapshot);
 647                 rc = -ENOMEM;
 648                 goto out;
 649         }
 650         p_info->offset = 0;
 651         p_info->debug_info_snap = debug_info_snapshot;
 652         p_info->debug_info_org  = debug_info;
 653         p_info->view = debug_info->views[i];
 654         p_info->act_area = 0;
 655         p_info->act_page = 0;
 656         p_info->act_entry = DEBUG_PROLOG_ENTRY;
 657         p_info->act_entry_offset = 0;
 658         file->private_data = p_info;
 659         debug_info_get(debug_info);
 660 out:
 661         mutex_unlock(&debug_mutex);
 662         return rc;
 663 }
 664
 665 /*
 666  * debug_close:
 667  * - called for user close()
 668  * - deletes  private_data area of the file handle
 669  */
 670
 671 static int
 672 debug_close(struct inode *inode, struct file *file)
 673 {
 674         file_private_info_t *p_info;
 675         p_info = (file_private_info_t *) file->private_data;
 676         if(p_info->debug_info_snap)
 677                 debug_info_free(p_info->debug_info_snap);
 678         debug_info_put(p_info->debug_info_org);
 679         kfree(file->private_data);
 680         return 0;               /* success */
 681 }
 682
 683 /*
 684  * debug_register_mode:
 685  * - Creates and initializes debug area for the caller
 686  *   The mode parameter allows to specify access rights for the s390dbf files
 687  * - Returns handle for debug area
 688  */
 689
 690 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
 691                                   int nr_areas, int buf_size, mode_t mode,
 692                                   uid_t uid, gid_t gid)
 693 {
 694         debug_info_t *rc = NULL;
 695
 696         /* Since debugfs currently does not support uid/gid other than root, */
 697         /* we do not allow gid/uid != 0 until we get support for that. */
 698         if ((uid != 0) || (gid != 0))
 699                 pr_warning("Root becomes the owner of all s390dbf files "
 700                            "in sysfs\n");
 701         if (!initialized)
 702                 BUG();
 703         mutex_lock(&debug_mutex);
 704
 705         /* create new debug_info */
 706
 707         rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
 708         if(!rc)
 709                 goto out;
 710         debug_register_view(rc, &debug_level_view);
 711         debug_register_view(rc, &debug_flush_view);
 712         debug_register_view(rc, &debug_pages_view);
 713 out:
 714         if (!rc){
 715                 pr_err("Registering debug feature %s failed\n", name);
 716         }
 717         mutex_unlock(&debug_mutex);
 718         return rc;
 719 }
 720 EXPORT_SYMBOL(debug_register_mode);
 721
 722 /*
 723  * debug_register:
 724  * - creates and initializes debug area for the caller
 725  * - returns handle for debug area
 726  */
 727
 728 debug_info_t *debug_register(const char *name, int pages_per_area,
 729                              int nr_areas, int buf_size)
 730 {
 731         return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
 732                                    S_IRUSR | S_IWUSR, 0, 0);
 733 }
 734
 735 /*
 736  * debug_unregister:
 737  * - give back debug area
 738  */
 739
 740 void
 741 debug_unregister(debug_info_t * id)
 742 {
 743         if (!id)
 744                 goto out;
 745         mutex_lock(&debug_mutex);
 746         debug_info_put(id);
 747         mutex_unlock(&debug_mutex);
 748
 749 out:
 750         return;
 751 }
 752
 753 /*
 754  * debug_set_size:
 755  * - set area size (number of pages) and number of areas
 756  */
 757 static int
 758 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
 759 {
 760         unsigned long flags;
 761         debug_entry_t *** new_areas;
 762         int rc=0;
 763
 764         if(!id || (nr_areas <= 0) || (pages_per_area < 0))
 765                 return -EINVAL;
 766         if(pages_per_area > 0){
 767                 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
 768                 if(!new_areas) {
 769                         pr_info("Allocating memory for %i pages failed\n",
 770                                 pages_per_area);
 771                         rc = -ENOMEM;
 772                         goto out;
 773                 }
 774         } else {
 775                 new_areas = NULL;
 776         }
 777         spin_lock_irqsave(&id->lock,flags);
 778         debug_areas_free(id);
 779         id->areas = new_areas;
 780         id->nr_areas = nr_areas;
 781         id->pages_per_area = pages_per_area;
 782         id->active_area = 0;
 783         memset(id->active_entries,0,sizeof(int)*id->nr_areas);
 784         memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
 785         spin_unlock_irqrestore(&id->lock,flags);
 786         pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
 787 out:
 788         return rc;
 789 }
 790
 791 /*
 792  * debug_set_level:
 793  * - set actual debug level
 794  */
 795
 796 void
 797 debug_set_level(debug_info_t* id, int new_level)
 798 {
 799         unsigned long flags;
 800         if(!id)
 801                 return;
 802         spin_lock_irqsave(&id->lock,flags);
 803         if(new_level == DEBUG_OFF_LEVEL){
 804                 id->level = DEBUG_OFF_LEVEL;
 805                 pr_info("%s: switched off\n",id->name);
 806         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
 807                 pr_info("%s: level %i is out of range (%i - %i)\n",
 808                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
 809         } else {
 810                 id->level = new_level;
 811         }
 812         spin_unlock_irqrestore(&id->lock,flags);
 813 }
 814
 815
 816 /*
 817  * proceed_active_entry:
 818  * - set active entry to next in the ring buffer
 819  */
 820
 821 static inline void
 822 proceed_active_entry(debug_info_t * id)
 823 {
 824         if ((id->active_entries[id->active_area] += id->entry_size)
 825             > (PAGE_SIZE - id->entry_size)){
 826                 id->active_entries[id->active_area] = 0;
 827                 id->active_pages[id->active_area] =
 828                         (id->active_pages[id->active_area] + 1) %
 829                         id->pages_per_area;
 830         }
 831 }
 832
 833 /*
 834  * proceed_active_area:
 835  * - set active area to next in the ring buffer
 836  */
 837
 838 static inline void
 839 proceed_active_area(debug_info_t * id)
 840 {
 841         id->active_area++;
 842         id->active_area = id->active_area % id->nr_areas;
 843 }
 844
 845 /*
 846  * get_active_entry:
 847  */
 848
 849 static inline debug_entry_t*
 850 get_active_entry(debug_info_t * id)
 851 {
 852         return (debug_entry_t *) (((char *) id->areas[id->active_area]
 853                                         [id->active_pages[id->active_area]]) +
 854                                         id->active_entries[id->active_area]);
 855 }
 856
 857 /*
 858  * debug_finish_entry:
 859  * - set timestamp, caller address, cpu number etc.
 860  */
 861
 862 static inline void
 863 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
 864                         int exception)
 865 {
 866         active->id.stck = get_clock();
 867         active->id.fields.cpuid = smp_processor_id();
 868         active->caller = __builtin_return_address(0);
 869         active->id.fields.exception = exception;
 870         active->id.fields.level     = level;
 871         proceed_active_entry(id);
 872         if(exception)
 873                 proceed_active_area(id);
 874 }
 875
 876 static int debug_stoppable=1;
 877 static int debug_active=1;
 878
 879 #define CTL_S390DBF_STOPPABLE 5678
 880 #define CTL_S390DBF_ACTIVE 5679
 881
 882 /*
 883  * proc handler for the running debug_active sysctl
 884  * always allow read, allow write only if debug_stoppable is set or
 885  * if debug_active is already off
 886  */
 887 static int
 888 s390dbf_procactive(ctl_table *table, int write, struct file *filp,
 889                      void __user *buffer, size_t *lenp, loff_t *ppos)
 890 {
 891         if (!write || debug_stoppable || !debug_active)
 892                 return proc_dointvec(table, write, filp, buffer, lenp, ppos);
 893         else
 894                 return 0;
 895 }
 896
 897
 898 static struct ctl_table s390dbf_table[] = {
 899         {
 900                 .ctl_name       = CTL_S390DBF_STOPPABLE,
 901                 .procname       = "debug_stoppable",
 902                 .data           = &debug_stoppable,
 903                 .maxlen         = sizeof(int),
 904                 .mode           = S_IRUGO | S_IWUSR,
 905                 .proc_handler   = &proc_dointvec,
 906                 .strategy       = &sysctl_intvec,
 907         },
 908          {
 909                 .ctl_name       = CTL_S390DBF_ACTIVE,
 910                 .procname       = "debug_active",
 911                 .data           = &debug_active,
 912                 .maxlen         = sizeof(int),
 913                 .mode           = S_IRUGO | S_IWUSR,
 914                 .proc_handler   = &s390dbf_procactive,
 915                 .strategy       = &sysctl_intvec,
 916         },
 917         { .ctl_name = 0 }
 918 };
 919
 920 static struct ctl_table s390dbf_dir_table[] = {
 921         {
 922                 .ctl_name       = CTL_S390DBF,
 923                 .procname       = "s390dbf",
 924                 .maxlen         = 0,
 925                 .mode           = S_IRUGO | S_IXUGO,
 926                 .child          = s390dbf_table,
 927         },
 928         { .ctl_name = 0 }
 929 };
 930
 931 static struct ctl_table_header *s390dbf_sysctl_header;
 932
 933 void
 934 debug_stop_all(void)
 935 {
 936         if (debug_stoppable)
 937                 debug_active = 0;
 938 }
 939
 940
 941 /*
 942  * debug_event_common:
 943  * - write debug entry with given size
 944  */
 945
 946 debug_entry_t*
 947 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
 948 {
 949         unsigned long flags;
 950         debug_entry_t *active;
 951
 952         if (!debug_active || !id->areas)
 953                 return NULL;
 954         spin_lock_irqsave(&id->lock, flags);
 955         active = get_active_entry(id);
 956         memset(DEBUG_DATA(active), 0, id->buf_size);
 957         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
 958         debug_finish_entry(id, active, level, 0);
 959         spin_unlock_irqrestore(&id->lock, flags);
 960
 961         return active;
 962 }
 963
 964 /*
 965  * debug_exception_common:
 966  * - write debug entry with given size and switch to next debug area
 967  */
 968
 969 debug_entry_t
 970 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
 971 {
 972         unsigned long flags;
 973         debug_entry_t *active;
 974
 975         if (!debug_active || !id->areas)
 976                 return NULL;
 977         spin_lock_irqsave(&id->lock, flags);
 978         active = get_active_entry(id);
 979         memset(DEBUG_DATA(active), 0, id->buf_size);
 980         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
 981         debug_finish_entry(id, active, level, 1);
 982         spin_unlock_irqrestore(&id->lock, flags);
 983
 984         return active;
 985 }
 986
 987 /*
 988  * counts arguments in format string for sprintf view
 989  */
 990
 991 static inline int
 992 debug_count_numargs(char *string)
 993 {
 994         int numargs=0;
 995
 996         while(*string) {
 997                 if(*string++=='%')
 998                         numargs++;
 999         }
1000         return(numargs);
1001 }
1002
1003 /*
1004  * debug_sprintf_event:
1005  */
1006
1007 debug_entry_t*
1008 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1009 {
1010         va_list   ap;
1011         int numargs,idx;
1012         unsigned long flags;
1013         debug_sprintf_entry_t *curr_event;
1014         debug_entry_t *active;
1015
1016         if((!id) || (level > id->level))
1017                 return NULL;
1018         if (!debug_active || !id->areas)
1019                 return NULL;
1020         numargs=debug_count_numargs(string);
1021
1022         spin_lock_irqsave(&id->lock, flags);
1023         active = get_active_entry(id);
1024         curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1025         va_start(ap,string);
1026         curr_event->string=string;
1027         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1028                 curr_event->args[idx]=va_arg(ap,long);
1029         va_end(ap);
1030         debug_finish_entry(id, active, level, 0);
1031         spin_unlock_irqrestore(&id->lock, flags);
1032
1033         return active;
1034 }
1035
1036 /*
1037  * debug_sprintf_exception:
1038  */
1039
1040 debug_entry_t*
1041 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1042 {
1043         va_list   ap;
1044         int numargs,idx;
1045         unsigned long flags;
1046         debug_sprintf_entry_t *curr_event;
1047         debug_entry_t *active;
1048
1049         if((!id) || (level > id->level))
1050                 return NULL;
1051         if (!debug_active || !id->areas)
1052                 return NULL;
1053
1054         numargs=debug_count_numargs(string);
1055
1056         spin_lock_irqsave(&id->lock, flags);
1057         active = get_active_entry(id);
1058         curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1059         va_start(ap,string);
1060         curr_event->string=string;
1061         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1062                 curr_event->args[idx]=va_arg(ap,long);
1063         va_end(ap);
1064         debug_finish_entry(id, active, level, 1);
1065         spin_unlock_irqrestore(&id->lock, flags);
1066
1067         return active;
1068 }
1069
1070 /*
1071  * debug_init:
1072  * - is called exactly once to initialize the debug feature
1073  */
1074
1075 static int
1076 __init debug_init(void)
1077 {
1078         int rc = 0;
1079
1080         s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1081         mutex_lock(&debug_mutex);
1082         debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1083         initialized = 1;
1084         mutex_unlock(&debug_mutex);
1085
1086         return rc;
1087 }
1088
1089 /*
1090  * debug_register_view:
1091  */
1092
1093 int
1094 debug_register_view(debug_info_t * id, struct debug_view *view)
1095 {
1096         int rc = 0;
1097         int i;
1098         unsigned long flags;
1099         mode_t mode;
1100         struct dentry *pde;
1101
1102         if (!id)
1103                 goto out;
1104         mode = (id->mode | S_IFREG) & ~S_IXUGO;
1105         if (!(view->prolog_proc || view->format_proc || view->header_proc))
1106                 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1107         if (!view->input_proc)
1108                 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1109         pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1110                                 id , &debug_file_ops);
1111         if (!pde){
1112                 pr_err("Registering view %s/%s failed due to out of "
1113                        "memory\n", id->name,view->name);
1114                 rc = -1;
1115                 goto out;
1116         }
1117         spin_lock_irqsave(&id->lock, flags);
1118         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1119                 if (!id->views[i])
1120                         break;
1121         }
1122         if (i == DEBUG_MAX_VIEWS) {
1123                 pr_err("Registering view %s/%s would exceed the maximum "
1124                        "number of views %i\n", id->name, view->name, i);
1125                 debugfs_remove(pde);
1126                 rc = -1;
1127         } else {
1128                 id->views[i] = view;
1129                 id->debugfs_entries[i] = pde;
1130         }
1131         spin_unlock_irqrestore(&id->lock, flags);
1132 out:
1133         return rc;
1134 }
1135
1136 /*
1137  * debug_unregister_view:
1138  */
1139
1140 int
1141 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1142 {
1143         int rc = 0;
1144         int i;
1145         unsigned long flags;
1146
1147         if (!id)
1148                 goto out;
1149         spin_lock_irqsave(&id->lock, flags);
1150         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1151                 if (id->views[i] == view)
1152                         break;
1153         }
1154         if (i == DEBUG_MAX_VIEWS)
1155                 rc = -1;
1156         else {
1157                 debugfs_remove(id->debugfs_entries[i]);
1158                 id->views[i] = NULL;
1159                 rc = 0;
1160         }
1161         spin_unlock_irqrestore(&id->lock, flags);
1162 out:
1163         return rc;
1164 }
1165
1166 static inline char *
1167 debug_get_user_string(const char __user *user_buf, size_t user_len)
1168 {
1169         char* buffer;
1170
1171         buffer = kmalloc(user_len + 1, GFP_KERNEL);
1172         if (!buffer)
1173                 return ERR_PTR(-ENOMEM);
1174         if (copy_from_user(buffer, user_buf, user_len) != 0) {
1175                 kfree(buffer);
1176                 return ERR_PTR(-EFAULT);
1177         }
1178         /* got the string, now strip linefeed. */
1179         if (buffer[user_len - 1] == '\n')
1180                 buffer[user_len - 1] = 0;
1181         else
1182                 buffer[user_len] = 0;
1183         return buffer;
1184 }
1185
1186 static inline int
1187 debug_get_uint(char *buf)
1188 {
1189         int rc;
1190
1191         for(; isspace(*buf); buf++);
1192         rc = simple_strtoul(buf, &buf, 10);
1193         if(*buf){
1194                 rc = -EINVAL;
1195         }
1196         return rc;
1197 }
1198
1199 /*
1200  * functions for debug-views
1201  ***********************************
1202 */
1203
1204 /*
1205  * prints out actual debug level
1206  */
1207
1208 static int
1209 debug_prolog_pages_fn(debug_info_t * id,
1210                                  struct debug_view *view, char *out_buf)
1211 {
1212         return sprintf(out_buf, "%i\n", id->pages_per_area);
1213 }
1214
1215 /*
1216  * reads new size (number of pages per debug area)
1217  */
1218
1219 static int
1220 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1221                         struct file *file, const char __user *user_buf,
1222                         size_t user_len, loff_t * offset)
1223 {
1224         char *str;
1225         int rc,new_pages;
1226
1227         if (user_len > 0x10000)
1228                 user_len = 0x10000;
1229         if (*offset != 0){
1230                 rc = -EPIPE;
1231                 goto out;
1232         }
1233         str = debug_get_user_string(user_buf,user_len);
1234         if(IS_ERR(str)){
1235                 rc = PTR_ERR(str);
1236                 goto out;
1237         }
1238         new_pages = debug_get_uint(str);
1239         if(new_pages < 0){
1240                 rc = -EINVAL;
1241                 goto free_str;
1242         }
1243         rc = debug_set_size(id,id->nr_areas, new_pages);
1244         if(rc != 0){
1245                 rc = -EINVAL;
1246                 goto free_str;
1247         }
1248         rc = user_len;
1249 free_str:
1250         kfree(str);
1251 out:
1252         *offset += user_len;
1253         return rc;              /* number of input characters */
1254 }
1255
1256 /*
1257  * prints out actual debug level
1258  */
1259
1260 static int
1261 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1262 {
1263         int rc = 0;
1264
1265         if(id->level == DEBUG_OFF_LEVEL) {
1266                 rc = sprintf(out_buf,"-\n");
1267         }
1268         else {
1269                 rc = sprintf(out_buf, "%i\n", id->level);
1270         }
1271         return rc;
1272 }
1273
1274 /*
1275  * reads new debug level
1276  */
1277
1278 static int
1279 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1280                         struct file *file, const char __user *user_buf,
1281                         size_t user_len, loff_t * offset)
1282 {
1283         char *str;
1284         int rc,new_level;
1285
1286         if (user_len > 0x10000)
1287                 user_len = 0x10000;
1288         if (*offset != 0){
1289                 rc = -EPIPE;
1290                 goto out;
1291         }
1292         str = debug_get_user_string(user_buf,user_len);
1293         if(IS_ERR(str)){
1294                 rc = PTR_ERR(str);
1295                 goto out;
1296         }
1297         if(str[0] == '-'){
1298                 debug_set_level(id, DEBUG_OFF_LEVEL);
1299                 rc = user_len;
1300                 goto free_str;
1301         } else {
1302                 new_level = debug_get_uint(str);
1303         }
1304         if(new_level < 0) {
1305                 pr_warning("%s is not a valid level for a debug "
1306                            "feature\n", str);
1307                 rc = -EINVAL;
1308         } else {
1309                 debug_set_level(id, new_level);
1310                 rc = user_len;
1311         }
1312 free_str:
1313         kfree(str);
1314 out:
1315         *offset += user_len;
1316         return rc;              /* number of input characters */
1317 }
1318
1319
1320 /*
1321  * flushes debug areas
1322  */
1323
1324 static void debug_flush(debug_info_t* id, int area)
1325 {
1326         unsigned long flags;
1327         int i,j;
1328
1329         if(!id || !id->areas)
1330                 return;
1331         spin_lock_irqsave(&id->lock,flags);
1332         if(area == DEBUG_FLUSH_ALL){
1333                 id->active_area = 0;
1334                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1335                 for (i = 0; i < id->nr_areas; i++) {
1336                         id->active_pages[i] = 0;
1337                         for(j = 0; j < id->pages_per_area; j++) {
1338                                 memset(id->areas[i][j], 0, PAGE_SIZE);
1339                         }
1340                 }
1341         } else if(area >= 0 && area < id->nr_areas) {
1342                 id->active_entries[area] = 0;
1343                 id->active_pages[area] = 0;
1344                 for(i = 0; i < id->pages_per_area; i++) {
1345                         memset(id->areas[area][i],0,PAGE_SIZE);
1346                 }
1347         }
1348         spin_unlock_irqrestore(&id->lock,flags);
1349 }
1350
1351 /*
1352  * view function: flushes debug areas
1353  */
1354
1355 static int
1356 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1357                         struct file *file, const char __user *user_buf,
1358                         size_t user_len, loff_t * offset)
1359 {
1360         char input_buf[1];
1361         int rc = user_len;
1362
1363         if (user_len > 0x10000)
1364                 user_len = 0x10000;
1365         if (*offset != 0){
1366                 rc = -EPIPE;
1367                 goto out;
1368         }
1369         if (copy_from_user(input_buf, user_buf, 1)){
1370                 rc = -EFAULT;
1371                 goto out;
1372         }
1373         if(input_buf[0] == '-') {
1374                 debug_flush(id, DEBUG_FLUSH_ALL);
1375                 goto out;
1376         }
1377         if (isdigit(input_buf[0])) {
1378                 int area = ((int) input_buf[0] - (int) '0');
1379                 debug_flush(id, area);
1380                 goto out;
1381         }
1382
1383         pr_info("Flushing debug data failed because %c is not a valid "
1384                  "area\n", input_buf[0]);
1385
1386 out:
1387         *offset += user_len;
1388         return rc;              /* number of input characters */
1389 }
1390
1391 /*
1392  * prints debug header in raw format
1393  */
1394
1395 static int
1396 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1397                         int area, debug_entry_t * entry, char *out_buf)
1398 {
1399         int rc;
1400
1401         rc = sizeof(debug_entry_t);
1402         memcpy(out_buf,entry,sizeof(debug_entry_t));
1403         return rc;
1404 }
1405
1406 /*
1407  * prints debug data in raw format
1408  */
1409
1410 static int
1411 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1412                                char *out_buf, const char *in_buf)
1413 {
1414         int rc;
1415
1416         rc = id->buf_size;
1417         memcpy(out_buf, in_buf, id->buf_size);
1418         return rc;
1419 }
1420
1421 /*
1422  * prints debug data in hex/ascii format
1423  */
1424
1425 static int
1426 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1427                           char *out_buf, const char *in_buf)
1428 {
1429         int i, rc = 0;
1430
1431         for (i = 0; i < id->buf_size; i++) {
1432                 rc += sprintf(out_buf + rc, "%02x ",
1433                               ((unsigned char *) in_buf)[i]);
1434         }
1435         rc += sprintf(out_buf + rc, "| ");
1436         for (i = 0; i < id->buf_size; i++) {
1437                 unsigned char c = in_buf[i];
1438                 if (!isprint(c))
1439                         rc += sprintf(out_buf + rc, ".");
1440                 else
1441                         rc += sprintf(out_buf + rc, "%c", c);
1442         }
1443         rc += sprintf(out_buf + rc, "\n");
1444         return rc;
1445 }
1446
1447 /*
1448  * prints header for debug entry
1449  */
1450
1451 int
1452 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1453                          int area, debug_entry_t * entry, char *out_buf)
1454 {
1455         struct timespec time_spec;
1456         unsigned long long time;
1457         char *except_str;
1458         unsigned long caller;
1459         int rc = 0;
1460         unsigned int level;
1461
1462         level = entry->id.fields.level;
1463         time = entry->id.stck;
1464         /* adjust todclock to 1970 */
1465         time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
1466         tod_to_timeval(time, &time_spec);
1467
1468         if (entry->id.fields.exception)
1469                 except_str = "*";
1470         else
1471                 except_str = "-";
1472         caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1473         rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
1474                       area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1475                       except_str, entry->id.fields.cpuid, (void *) caller);
1476         return rc;
1477 }
1478
1479 /*
1480  * prints debug data sprintf-formated:
1481  * debug_sprinf_event/exception calls must be used together with this view
1482  */
1483
1484 #define DEBUG_SPRINTF_MAX_ARGS 10
1485
1486 static int
1487 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1488                         char *out_buf, debug_sprintf_entry_t *curr_event)
1489 {
1490         int num_longs, num_used_args = 0,i, rc = 0;
1491         int index[DEBUG_SPRINTF_MAX_ARGS];
1492
1493         /* count of longs fit into one entry */
1494         num_longs = id->buf_size /  sizeof(long);
1495
1496         if(num_longs < 1)
1497                 goto out; /* bufsize of entry too small */
1498         if(num_longs == 1) {
1499                 /* no args, we use only the string */
1500                 strcpy(out_buf, curr_event->string);
1501                 rc = strlen(curr_event->string);
1502                 goto out;
1503         }
1504
1505         /* number of arguments used for sprintf (without the format string) */
1506         num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1507
1508         memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1509
1510         for(i = 0; i < num_used_args; i++)
1511                 index[i] = i;
1512
1513         rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1514                 curr_event->args[index[1]], curr_event->args[index[2]],
1515                 curr_event->args[index[3]], curr_event->args[index[4]],
1516                 curr_event->args[index[5]], curr_event->args[index[6]],
1517                 curr_event->args[index[7]], curr_event->args[index[8]],
1518                 curr_event->args[index[9]]);
1519
1520 out:
1521
1522         return rc;
1523 }
1524
1525 /*
1526  * clean up module
1527  */
1528 static void __exit debug_exit(void)
1529 {
1530         debugfs_remove(debug_debugfs_root_entry);
1531         unregister_sysctl_table(s390dbf_sysctl_header);
1532         return;
1533 }
1534
1535 /*
1536  * module definitions
1537  */
1538 postcore_initcall(debug_init);
1539 module_exit(debug_exit);
1540 MODULE_LICENSE("GPL");
1541
1542 EXPORT_SYMBOL(debug_register);
1543 EXPORT_SYMBOL(debug_unregister);
1544 EXPORT_SYMBOL(debug_set_level);
1545 EXPORT_SYMBOL(debug_stop_all);
1546 EXPORT_SYMBOL(debug_register_view);
1547 EXPORT_SYMBOL(debug_unregister_view);
1548 EXPORT_SYMBOL(debug_event_common);
1549 EXPORT_SYMBOL(debug_exception_common);
1550 EXPORT_SYMBOL(debug_hex_ascii_view);
1551 EXPORT_SYMBOL(debug_raw_view);
1552 EXPORT_SYMBOL(debug_dflt_header_fn);
1553 EXPORT_SYMBOL(debug_sprintf_view);
1554 EXPORT_SYMBOL(debug_sprintf_exception);
1555 EXPORT_SYMBOL(debug_sprintf_event);