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