arch/s390/kernel/debug.c

   1 /*
   2  *   S/390 debug facility
   3  *
   4  *    Copyright IBM Corp. 1999, 2012
   5  *
   6  *    Author(s): Michael Holzheu (holzheu@de.ibm.com),
   7  *               Holger Smolinski (Holger.Smolinski@de.ibm.com)
   8  *
   9  *    Bugreports to: <Linux390@de.ibm.com>
  10  */
  11
  12 #define KMSG_COMPONENT "s390dbf"
  13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  14
  15 #include <linux/stddef.h>
  16 #include <linux/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/slab.h>
  19 #include <linux/ctype.h>
  20 #include <linux/string.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 /* internal function prototyes */
  67
  68 static int debug_init(void);
  69 static ssize_t debug_output(struct file *file, char __user *user_buf,
  70                         size_t user_len, loff_t * offset);
  71 static ssize_t debug_input(struct file *file, const char __user *user_buf,
  72                         size_t user_len, loff_t * offset);
  73 static int debug_open(struct inode *inode, struct file *file);
  74 static int debug_close(struct inode *inode, struct file *file);
  75 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
  76                         int nr_areas, int buf_size, umode_t mode);
  77 static void debug_info_get(debug_info_t *);
  78 static void debug_info_put(debug_info_t *);
  79 static int debug_prolog_level_fn(debug_info_t * id,
  80                         struct debug_view *view, char *out_buf);
  81 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
  82                         struct file *file, const char __user *user_buf,
  83                         size_t user_buf_size, loff_t * offset);
  84 static int debug_prolog_pages_fn(debug_info_t * id,
  85                         struct debug_view *view, char *out_buf);
  86 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
  87                         struct file *file, const char __user *user_buf,
  88                         size_t user_buf_size, loff_t * offset);
  89 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
  90                         struct file *file, const char __user *user_buf,
  91                         size_t user_buf_size, loff_t * offset);
  92 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
  93                         char *out_buf, const char *in_buf);
  94 static int debug_raw_format_fn(debug_info_t * id,
  95                         struct debug_view *view, char *out_buf,
  96                         const char *in_buf);
  97 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
  98                         int area, debug_entry_t * entry, char *out_buf);
  99
 100 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
 101                         char *out_buf, debug_sprintf_entry_t *curr_event);
 102
 103 /* globals */
 104
 105 struct debug_view debug_raw_view = {
 106         "raw",
 107         NULL,
 108         &debug_raw_header_fn,
 109         &debug_raw_format_fn,
 110         NULL,
 111         NULL
 112 };
 113
 114 struct debug_view debug_hex_ascii_view = {
 115         "hex_ascii",
 116         NULL,
 117         &debug_dflt_header_fn,
 118         &debug_hex_ascii_format_fn,
 119         NULL,
 120         NULL
 121 };
 122
 123 static struct debug_view debug_level_view = {
 124         "level",
 125         &debug_prolog_level_fn,
 126         NULL,
 127         NULL,
 128         &debug_input_level_fn,
 129         NULL
 130 };
 131
 132 static struct debug_view debug_pages_view = {
 133         "pages",
 134         &debug_prolog_pages_fn,
 135         NULL,
 136         NULL,
 137         &debug_input_pages_fn,
 138         NULL
 139 };
 140
 141 static struct debug_view debug_flush_view = {
 142         "flush",
 143         NULL,
 144         NULL,
 145         NULL,
 146         &debug_input_flush_fn,
 147         NULL
 148 };
 149
 150 struct debug_view debug_sprintf_view = {
 151         "sprintf",
 152         NULL,
 153         &debug_dflt_header_fn,
 154         (debug_format_proc_t*)&debug_sprintf_format_fn,
 155         NULL,
 156         NULL
 157 };
 158
 159 /* used by dump analysis tools to determine version of debug feature */
 160 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
 161
 162 /* static globals */
 163
 164 static debug_info_t *debug_area_first = NULL;
 165 static debug_info_t *debug_area_last = NULL;
 166 static DEFINE_MUTEX(debug_mutex);
 167
 168 static int initialized;
 169 static int debug_critical;
 170
 171 static const struct file_operations debug_file_ops = {
 172         .owner   = THIS_MODULE,
 173         .read    = debug_output,
 174         .write   = debug_input,
 175         .open    = debug_open,
 176         .release = debug_close,
 177         .llseek  = no_llseek,
 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, umode_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, 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                 debug_info_free(debug_info_snapshot);
 646                 rc = -ENOMEM;
 647                 goto out;
 648         }
 649         p_info->offset = 0;
 650         p_info->debug_info_snap = debug_info_snapshot;
 651         p_info->debug_info_org  = debug_info;
 652         p_info->view = debug_info->views[i];
 653         p_info->act_area = 0;
 654         p_info->act_page = 0;
 655         p_info->act_entry = DEBUG_PROLOG_ENTRY;
 656         p_info->act_entry_offset = 0;
 657         file->private_data = p_info;
 658         debug_info_get(debug_info);
 659         nonseekable_open(inode, file);
 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, umode_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         BUG_ON(!initialized);
 702         mutex_lock(&debug_mutex);
 703
 704         /* create new debug_info */
 705
 706         rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
 707         if(!rc)
 708                 goto out;
 709         debug_register_view(rc, &debug_level_view);
 710         debug_register_view(rc, &debug_flush_view);
 711         debug_register_view(rc, &debug_pages_view);
 712 out:
 713         if (!rc){
 714                 pr_err("Registering debug feature %s failed\n", name);
 715         }
 716         mutex_unlock(&debug_mutex);
 717         return rc;
 718 }
 719 EXPORT_SYMBOL(debug_register_mode);
 720
 721 /*
 722  * debug_register:
 723  * - creates and initializes debug area for the caller
 724  * - returns handle for debug area
 725  */
 726
 727 debug_info_t *debug_register(const char *name, int pages_per_area,
 728                              int nr_areas, int buf_size)
 729 {
 730         return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
 731                                    S_IRUSR | S_IWUSR, 0, 0);
 732 }
 733
 734 /*
 735  * debug_unregister:
 736  * - give back debug area
 737  */
 738
 739 void
 740 debug_unregister(debug_info_t * id)
 741 {
 742         if (!id)
 743                 goto out;
 744         mutex_lock(&debug_mutex);
 745         debug_info_put(id);
 746         mutex_unlock(&debug_mutex);
 747
 748 out:
 749         return;
 750 }
 751
 752 /*
 753  * debug_set_size:
 754  * - set area size (number of pages) and number of areas
 755  */
 756 static int
 757 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
 758 {
 759         unsigned long flags;
 760         debug_entry_t *** new_areas;
 761         int rc=0;
 762
 763         if(!id || (nr_areas <= 0) || (pages_per_area < 0))
 764                 return -EINVAL;
 765         if(pages_per_area > 0){
 766                 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
 767                 if(!new_areas) {
 768                         pr_info("Allocating memory for %i pages failed\n",
 769                                 pages_per_area);
 770                         rc = -ENOMEM;
 771                         goto out;
 772                 }
 773         } else {
 774                 new_areas = NULL;
 775         }
 776         spin_lock_irqsave(&id->lock,flags);
 777         debug_areas_free(id);
 778         id->areas = new_areas;
 779         id->nr_areas = nr_areas;
 780         id->pages_per_area = pages_per_area;
 781         id->active_area = 0;
 782         memset(id->active_entries,0,sizeof(int)*id->nr_areas);
 783         memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
 784         spin_unlock_irqrestore(&id->lock,flags);
 785         pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
 786 out:
 787         return rc;
 788 }
 789
 790 /*
 791  * debug_set_level:
 792  * - set actual debug level
 793  */
 794
 795 void
 796 debug_set_level(debug_info_t* id, int new_level)
 797 {
 798         unsigned long flags;
 799         if(!id)
 800                 return;
 801         spin_lock_irqsave(&id->lock,flags);
 802         if(new_level == DEBUG_OFF_LEVEL){
 803                 id->level = DEBUG_OFF_LEVEL;
 804                 pr_info("%s: switched off\n",id->name);
 805         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
 806                 pr_info("%s: level %i is out of range (%i - %i)\n",
 807                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
 808         } else {
 809                 id->level = new_level;
 810         }
 811         spin_unlock_irqrestore(&id->lock,flags);
 812 }
 813
 814
 815 /*
 816  * proceed_active_entry:
 817  * - set active entry to next in the ring buffer
 818  */
 819
 820 static inline void
 821 proceed_active_entry(debug_info_t * id)
 822 {
 823         if ((id->active_entries[id->active_area] += id->entry_size)
 824             > (PAGE_SIZE - id->entry_size)){
 825                 id->active_entries[id->active_area] = 0;
 826                 id->active_pages[id->active_area] =
 827                         (id->active_pages[id->active_area] + 1) %
 828                         id->pages_per_area;
 829         }
 830 }
 831
 832 /*
 833  * proceed_active_area:
 834  * - set active area to next in the ring buffer
 835  */
 836
 837 static inline void
 838 proceed_active_area(debug_info_t * id)
 839 {
 840         id->active_area++;
 841         id->active_area = id->active_area % id->nr_areas;
 842 }
 843
 844 /*
 845  * get_active_entry:
 846  */
 847
 848 static inline debug_entry_t*
 849 get_active_entry(debug_info_t * id)
 850 {
 851         return (debug_entry_t *) (((char *) id->areas[id->active_area]
 852                                         [id->active_pages[id->active_area]]) +
 853                                         id->active_entries[id->active_area]);
 854 }
 855
 856 /*
 857  * debug_finish_entry:
 858  * - set timestamp, caller address, cpu number etc.
 859  */
 860
 861 static inline void
 862 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
 863                         int exception)
 864 {
 865         active->id.stck = get_clock();
 866         active->id.fields.cpuid = smp_processor_id();
 867         active->caller = __builtin_return_address(0);
 868         active->id.fields.exception = exception;
 869         active->id.fields.level     = level;
 870         proceed_active_entry(id);
 871         if(exception)
 872                 proceed_active_area(id);
 873 }
 874
 875 static int debug_stoppable=1;
 876 static int debug_active=1;
 877
 878 #define CTL_S390DBF_STOPPABLE 5678
 879 #define CTL_S390DBF_ACTIVE 5679
 880
 881 /*
 882  * proc handler for the running debug_active sysctl
 883  * always allow read, allow write only if debug_stoppable is set or
 884  * if debug_active is already off
 885  */
 886 static int
 887 s390dbf_procactive(ctl_table *table, int write,
 888                      void __user *buffer, size_t *lenp, loff_t *ppos)
 889 {
 890         if (!write || debug_stoppable || !debug_active)
 891                 return proc_dointvec(table, write, buffer, lenp, ppos);
 892         else
 893                 return 0;
 894 }
 895
 896
 897 static struct ctl_table s390dbf_table[] = {
 898         {
 899                 .procname       = "debug_stoppable",
 900                 .data           = &debug_stoppable,
 901                 .maxlen         = sizeof(int),
 902                 .mode           = S_IRUGO | S_IWUSR,
 903                 .proc_handler   = proc_dointvec,
 904         },
 905          {
 906                 .procname       = "debug_active",
 907                 .data           = &debug_active,
 908                 .maxlen         = sizeof(int),
 909                 .mode           = S_IRUGO | S_IWUSR,
 910                 .proc_handler   = s390dbf_procactive,
 911         },
 912         { }
 913 };
 914
 915 static struct ctl_table s390dbf_dir_table[] = {
 916         {
 917                 .procname       = "s390dbf",
 918                 .maxlen         = 0,
 919                 .mode           = S_IRUGO | S_IXUGO,
 920                 .child          = s390dbf_table,
 921         },
 922         { }
 923 };
 924
 925 static struct ctl_table_header *s390dbf_sysctl_header;
 926
 927 void
 928 debug_stop_all(void)
 929 {
 930         if (debug_stoppable)
 931                 debug_active = 0;
 932 }
 933
 934
 935 void debug_set_critical(void)
 936 {
 937         debug_critical = 1;
 938 }
 939
 940 /*
 941  * debug_event_common:
 942  * - write debug entry with given size
 943  */
 944
 945 debug_entry_t*
 946 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
 947 {
 948         unsigned long flags;
 949         debug_entry_t *active;
 950
 951         if (!debug_active || !id->areas)
 952                 return NULL;
 953         if (debug_critical) {
 954                 if (!spin_trylock_irqsave(&id->lock, flags))
 955                         return NULL;
 956         } else
 957                 spin_lock_irqsave(&id->lock, flags);
 958         active = get_active_entry(id);
 959         memset(DEBUG_DATA(active), 0, id->buf_size);
 960         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
 961         debug_finish_entry(id, active, level, 0);
 962         spin_unlock_irqrestore(&id->lock, flags);
 963
 964         return active;
 965 }
 966
 967 /*
 968  * debug_exception_common:
 969  * - write debug entry with given size and switch to next debug area
 970  */
 971
 972 debug_entry_t
 973 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
 974 {
 975         unsigned long flags;
 976         debug_entry_t *active;
 977
 978         if (!debug_active || !id->areas)
 979                 return NULL;
 980         if (debug_critical) {
 981                 if (!spin_trylock_irqsave(&id->lock, flags))
 982                         return NULL;
 983         } else
 984                 spin_lock_irqsave(&id->lock, flags);
 985         active = get_active_entry(id);
 986         memset(DEBUG_DATA(active), 0, id->buf_size);
 987         memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
 988         debug_finish_entry(id, active, level, 1);
 989         spin_unlock_irqrestore(&id->lock, flags);
 990
 991         return active;
 992 }
 993
 994 /*
 995  * counts arguments in format string for sprintf view
 996  */
 997
 998 static inline int
 999 debug_count_numargs(char *string)
1000 {
1001         int numargs=0;
1002
1003         while(*string) {
1004                 if(*string++=='%')
1005                         numargs++;
1006         }
1007         return(numargs);
1008 }
1009
1010 /*
1011  * debug_sprintf_event:
1012  */
1013
1014 debug_entry_t*
1015 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1016 {
1017         va_list   ap;
1018         int numargs,idx;
1019         unsigned long flags;
1020         debug_sprintf_entry_t *curr_event;
1021         debug_entry_t *active;
1022
1023         if((!id) || (level > id->level))
1024                 return NULL;
1025         if (!debug_active || !id->areas)
1026                 return NULL;
1027         numargs=debug_count_numargs(string);
1028
1029         if (debug_critical) {
1030                 if (!spin_trylock_irqsave(&id->lock, flags))
1031                         return NULL;
1032         } else
1033                 spin_lock_irqsave(&id->lock, flags);
1034         active = get_active_entry(id);
1035         curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1036         va_start(ap,string);
1037         curr_event->string=string;
1038         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1039                 curr_event->args[idx]=va_arg(ap,long);
1040         va_end(ap);
1041         debug_finish_entry(id, active, level, 0);
1042         spin_unlock_irqrestore(&id->lock, flags);
1043
1044         return active;
1045 }
1046
1047 /*
1048  * debug_sprintf_exception:
1049  */
1050
1051 debug_entry_t*
1052 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1053 {
1054         va_list   ap;
1055         int numargs,idx;
1056         unsigned long flags;
1057         debug_sprintf_entry_t *curr_event;
1058         debug_entry_t *active;
1059
1060         if((!id) || (level > id->level))
1061                 return NULL;
1062         if (!debug_active || !id->areas)
1063                 return NULL;
1064
1065         numargs=debug_count_numargs(string);
1066
1067         if (debug_critical) {
1068                 if (!spin_trylock_irqsave(&id->lock, flags))
1069                         return NULL;
1070         } else
1071                 spin_lock_irqsave(&id->lock, flags);
1072         active = get_active_entry(id);
1073         curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1074         va_start(ap,string);
1075         curr_event->string=string;
1076         for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1077                 curr_event->args[idx]=va_arg(ap,long);
1078         va_end(ap);
1079         debug_finish_entry(id, active, level, 1);
1080         spin_unlock_irqrestore(&id->lock, flags);
1081
1082         return active;
1083 }
1084
1085 /*
1086  * debug_init:
1087  * - is called exactly once to initialize the debug feature
1088  */
1089
1090 static int
1091 __init debug_init(void)
1092 {
1093         int rc = 0;
1094
1095         s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1096         mutex_lock(&debug_mutex);
1097         debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1098         initialized = 1;
1099         mutex_unlock(&debug_mutex);
1100
1101         return rc;
1102 }
1103
1104 /*
1105  * debug_register_view:
1106  */
1107
1108 int
1109 debug_register_view(debug_info_t * id, struct debug_view *view)
1110 {
1111         int rc = 0;
1112         int i;
1113         unsigned long flags;
1114         umode_t mode;
1115         struct dentry *pde;
1116
1117         if (!id)
1118                 goto out;
1119         mode = (id->mode | S_IFREG) & ~S_IXUGO;
1120         if (!(view->prolog_proc || view->format_proc || view->header_proc))
1121                 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1122         if (!view->input_proc)
1123                 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1124         pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1125                                 id , &debug_file_ops);
1126         if (!pde){
1127                 pr_err("Registering view %s/%s failed due to out of "
1128                        "memory\n", id->name,view->name);
1129                 rc = -1;
1130                 goto out;
1131         }
1132         spin_lock_irqsave(&id->lock, flags);
1133         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1134                 if (!id->views[i])
1135                         break;
1136         }
1137         if (i == DEBUG_MAX_VIEWS) {
1138                 pr_err("Registering view %s/%s would exceed the maximum "
1139                        "number of views %i\n", id->name, view->name, i);
1140                 debugfs_remove(pde);
1141                 rc = -1;
1142         } else {
1143                 id->views[i] = view;
1144                 id->debugfs_entries[i] = pde;
1145         }
1146         spin_unlock_irqrestore(&id->lock, flags);
1147 out:
1148         return rc;
1149 }
1150
1151 /*
1152  * debug_unregister_view:
1153  */
1154
1155 int
1156 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1157 {
1158         int rc = 0;
1159         int i;
1160         unsigned long flags;
1161
1162         if (!id)
1163                 goto out;
1164         spin_lock_irqsave(&id->lock, flags);
1165         for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1166                 if (id->views[i] == view)
1167                         break;
1168         }
1169         if (i == DEBUG_MAX_VIEWS)
1170                 rc = -1;
1171         else {
1172                 debugfs_remove(id->debugfs_entries[i]);
1173                 id->views[i] = NULL;
1174         }
1175         spin_unlock_irqrestore(&id->lock, flags);
1176 out:
1177         return rc;
1178 }
1179
1180 static inline char *
1181 debug_get_user_string(const char __user *user_buf, size_t user_len)
1182 {
1183         char* buffer;
1184
1185         buffer = kmalloc(user_len + 1, GFP_KERNEL);
1186         if (!buffer)
1187                 return ERR_PTR(-ENOMEM);
1188         if (copy_from_user(buffer, user_buf, user_len) != 0) {
1189                 kfree(buffer);
1190                 return ERR_PTR(-EFAULT);
1191         }
1192         /* got the string, now strip linefeed. */
1193         if (buffer[user_len - 1] == '\n')
1194                 buffer[user_len - 1] = 0;
1195         else
1196                 buffer[user_len] = 0;
1197         return buffer;
1198 }
1199
1200 static inline int
1201 debug_get_uint(char *buf)
1202 {
1203         int rc;
1204
1205         buf = skip_spaces(buf);
1206         rc = simple_strtoul(buf, &buf, 10);
1207         if(*buf){
1208                 rc = -EINVAL;
1209         }
1210         return rc;
1211 }
1212
1213 /*
1214  * functions for debug-views
1215  ***********************************
1216 */
1217
1218 /*
1219  * prints out actual debug level
1220  */
1221
1222 static int
1223 debug_prolog_pages_fn(debug_info_t * id,
1224                                  struct debug_view *view, char *out_buf)
1225 {
1226         return sprintf(out_buf, "%i\n", id->pages_per_area);
1227 }
1228
1229 /*
1230  * reads new size (number of pages per debug area)
1231  */
1232
1233 static int
1234 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1235                         struct file *file, const char __user *user_buf,
1236                         size_t user_len, loff_t * offset)
1237 {
1238         char *str;
1239         int rc,new_pages;
1240
1241         if (user_len > 0x10000)
1242                 user_len = 0x10000;
1243         if (*offset != 0){
1244                 rc = -EPIPE;
1245                 goto out;
1246         }
1247         str = debug_get_user_string(user_buf,user_len);
1248         if(IS_ERR(str)){
1249                 rc = PTR_ERR(str);
1250                 goto out;
1251         }
1252         new_pages = debug_get_uint(str);
1253         if(new_pages < 0){
1254                 rc = -EINVAL;
1255                 goto free_str;
1256         }
1257         rc = debug_set_size(id,id->nr_areas, new_pages);
1258         if(rc != 0){
1259                 rc = -EINVAL;
1260                 goto free_str;
1261         }
1262         rc = user_len;
1263 free_str:
1264         kfree(str);
1265 out:
1266         *offset += user_len;
1267         return rc;              /* number of input characters */
1268 }
1269
1270 /*
1271  * prints out actual debug level
1272  */
1273
1274 static int
1275 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1276 {
1277         int rc = 0;
1278
1279         if(id->level == DEBUG_OFF_LEVEL) {
1280                 rc = sprintf(out_buf,"-\n");
1281         }
1282         else {
1283                 rc = sprintf(out_buf, "%i\n", id->level);
1284         }
1285         return rc;
1286 }
1287
1288 /*
1289  * reads new debug level
1290  */
1291
1292 static int
1293 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1294                         struct file *file, const char __user *user_buf,
1295                         size_t user_len, loff_t * offset)
1296 {
1297         char *str;
1298         int rc,new_level;
1299
1300         if (user_len > 0x10000)
1301                 user_len = 0x10000;
1302         if (*offset != 0){
1303                 rc = -EPIPE;
1304                 goto out;
1305         }
1306         str = debug_get_user_string(user_buf,user_len);
1307         if(IS_ERR(str)){
1308                 rc = PTR_ERR(str);
1309                 goto out;
1310         }
1311         if(str[0] == '-'){
1312                 debug_set_level(id, DEBUG_OFF_LEVEL);
1313                 rc = user_len;
1314                 goto free_str;
1315         } else {
1316                 new_level = debug_get_uint(str);
1317         }
1318         if(new_level < 0) {
1319                 pr_warning("%s is not a valid level for a debug "
1320                            "feature\n", str);
1321                 rc = -EINVAL;
1322         } else {
1323                 debug_set_level(id, new_level);
1324                 rc = user_len;
1325         }
1326 free_str:
1327         kfree(str);
1328 out:
1329         *offset += user_len;
1330         return rc;              /* number of input characters */
1331 }
1332
1333
1334 /*
1335  * flushes debug areas
1336  */
1337
1338 static void debug_flush(debug_info_t* id, int area)
1339 {
1340         unsigned long flags;
1341         int i,j;
1342
1343         if(!id || !id->areas)
1344                 return;
1345         spin_lock_irqsave(&id->lock,flags);
1346         if(area == DEBUG_FLUSH_ALL){
1347                 id->active_area = 0;
1348                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1349                 for (i = 0; i < id->nr_areas; i++) {
1350                         id->active_pages[i] = 0;
1351                         for(j = 0; j < id->pages_per_area; j++) {
1352                                 memset(id->areas[i][j], 0, PAGE_SIZE);
1353                         }
1354                 }
1355         } else if(area >= 0 && area < id->nr_areas) {
1356                 id->active_entries[area] = 0;
1357                 id->active_pages[area] = 0;
1358                 for(i = 0; i < id->pages_per_area; i++) {
1359                         memset(id->areas[area][i],0,PAGE_SIZE);
1360                 }
1361         }
1362         spin_unlock_irqrestore(&id->lock,flags);
1363 }
1364
1365 /*
1366  * view function: flushes debug areas
1367  */
1368
1369 static int
1370 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1371                         struct file *file, const char __user *user_buf,
1372                         size_t user_len, loff_t * offset)
1373 {
1374         char input_buf[1];
1375         int rc = user_len;
1376
1377         if (user_len > 0x10000)
1378                 user_len = 0x10000;
1379         if (*offset != 0){
1380                 rc = -EPIPE;
1381                 goto out;
1382         }
1383         if (copy_from_user(input_buf, user_buf, 1)){
1384                 rc = -EFAULT;
1385                 goto out;
1386         }
1387         if(input_buf[0] == '-') {
1388                 debug_flush(id, DEBUG_FLUSH_ALL);
1389                 goto out;
1390         }
1391         if (isdigit(input_buf[0])) {
1392                 int area = ((int) input_buf[0] - (int) '0');
1393                 debug_flush(id, area);
1394                 goto out;
1395         }
1396
1397         pr_info("Flushing debug data failed because %c is not a valid "
1398                  "area\n", input_buf[0]);
1399
1400 out:
1401         *offset += user_len;
1402         return rc;              /* number of input characters */
1403 }
1404
1405 /*
1406  * prints debug header in raw format
1407  */
1408
1409 static int
1410 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1411                         int area, debug_entry_t * entry, char *out_buf)
1412 {
1413         int rc;
1414
1415         rc = sizeof(debug_entry_t);
1416         memcpy(out_buf,entry,sizeof(debug_entry_t));
1417         return rc;
1418 }
1419
1420 /*
1421  * prints debug data in raw format
1422  */
1423
1424 static int
1425 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1426                                char *out_buf, const char *in_buf)
1427 {
1428         int rc;
1429
1430         rc = id->buf_size;
1431         memcpy(out_buf, in_buf, id->buf_size);
1432         return rc;
1433 }
1434
1435 /*
1436  * prints debug data in hex/ascii format
1437  */
1438
1439 static int
1440 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1441                           char *out_buf, const char *in_buf)
1442 {
1443         int i, rc = 0;
1444
1445         for (i = 0; i < id->buf_size; i++) {
1446                 rc += sprintf(out_buf + rc, "%02x ",
1447                               ((unsigned char *) in_buf)[i]);
1448         }
1449         rc += sprintf(out_buf + rc, "| ");
1450         for (i = 0; i < id->buf_size; i++) {
1451                 unsigned char c = in_buf[i];
1452                 if (isascii(c) && isprint(c))
1453                         rc += sprintf(out_buf + rc, "%c", c);
1454                 else
1455                         rc += sprintf(out_buf + rc, ".");
1456         }
1457         rc += sprintf(out_buf + rc, "\n");
1458         return rc;
1459 }
1460
1461 /*
1462  * prints header for debug entry
1463  */
1464
1465 int
1466 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1467                          int area, debug_entry_t * entry, char *out_buf)
1468 {
1469         struct timespec time_spec;
1470         char *except_str;
1471         unsigned long caller;
1472         int rc = 0;
1473         unsigned int level;
1474
1475         level = entry->id.fields.level;
1476         stck_to_timespec(entry->id.stck, &time_spec);
1477
1478         if (entry->id.fields.exception)
1479                 except_str = "*";
1480         else
1481                 except_str = "-";
1482         caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1483         rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p  ",
1484                       area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1485                       except_str, entry->id.fields.cpuid, (void *) caller);
1486         return rc;
1487 }
1488
1489 /*
1490  * prints debug data sprintf-formated:
1491  * debug_sprinf_event/exception calls must be used together with this view
1492  */
1493
1494 #define DEBUG_SPRINTF_MAX_ARGS 10
1495
1496 static int
1497 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1498                         char *out_buf, debug_sprintf_entry_t *curr_event)
1499 {
1500         int num_longs, num_used_args = 0,i, rc = 0;
1501         int index[DEBUG_SPRINTF_MAX_ARGS];
1502
1503         /* count of longs fit into one entry */
1504         num_longs = id->buf_size /  sizeof(long);
1505
1506         if(num_longs < 1)
1507                 goto out; /* bufsize of entry too small */
1508         if(num_longs == 1) {
1509                 /* no args, we use only the string */
1510                 strcpy(out_buf, curr_event->string);
1511                 rc = strlen(curr_event->string);
1512                 goto out;
1513         }
1514
1515         /* number of arguments used for sprintf (without the format string) */
1516         num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1517
1518         memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1519
1520         for(i = 0; i < num_used_args; i++)
1521                 index[i] = i;
1522
1523         rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1524                 curr_event->args[index[1]], curr_event->args[index[2]],
1525                 curr_event->args[index[3]], curr_event->args[index[4]],
1526                 curr_event->args[index[5]], curr_event->args[index[6]],
1527                 curr_event->args[index[7]], curr_event->args[index[8]],
1528                 curr_event->args[index[9]]);
1529
1530 out:
1531
1532         return rc;
1533 }
1534
1535 /*
1536  * clean up module
1537  */
1538 static void __exit debug_exit(void)
1539 {
1540         debugfs_remove(debug_debugfs_root_entry);
1541         unregister_sysctl_table(s390dbf_sysctl_header);
1542         return;
1543 }
1544
1545 /*
1546  * module definitions
1547  */
1548 postcore_initcall(debug_init);
1549 module_exit(debug_exit);
1550 MODULE_LICENSE("GPL");
1551
1552 EXPORT_SYMBOL(debug_register);
1553 EXPORT_SYMBOL(debug_unregister);
1554 EXPORT_SYMBOL(debug_set_level);
1555 EXPORT_SYMBOL(debug_stop_all);
1556 EXPORT_SYMBOL(debug_register_view);
1557 EXPORT_SYMBOL(debug_unregister_view);
1558 EXPORT_SYMBOL(debug_event_common);
1559 EXPORT_SYMBOL(debug_exception_common);
1560 EXPORT_SYMBOL(debug_hex_ascii_view);
1561 EXPORT_SYMBOL(debug_raw_view);
1562 EXPORT_SYMBOL(debug_dflt_header_fn);
1563 EXPORT_SYMBOL(debug_sprintf_view);
1564 EXPORT_SYMBOL(debug_sprintf_exception);
1565 EXPORT_SYMBOL(debug_sprintf_event);