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, 885 void __user *buffer, size_t *lenp, loff_t *ppos) 886 { 887 if (!write || debug_stoppable || !debug_active) 888 return proc_dointvec(table, write, buffer, lenp, ppos); 889 else 890 return 0; 891 } 892 893 894 static struct ctl_table s390dbf_table[] = { 895 { 896 .procname = "debug_stoppable", 897 .data = &debug_stoppable, 898 .maxlen = sizeof(int), 899 .mode = S_IRUGO | S_IWUSR, 900 .proc_handler = proc_dointvec, 901 }, 902 { 903 .procname = "debug_active", 904 .data = &debug_active, 905 .maxlen = sizeof(int), 906 .mode = S_IRUGO | S_IWUSR, 907 .proc_handler = s390dbf_procactive, 908 }, 909 { } 910 }; 911 912 static struct ctl_table s390dbf_dir_table[] = { 913 { 914 .procname = "s390dbf", 915 .maxlen = 0, 916 .mode = S_IRUGO | S_IXUGO, 917 .child = s390dbf_table, 918 }, 919 { } 920 }; 921 922 static struct ctl_table_header *s390dbf_sysctl_header; 923 924 void 925 debug_stop_all(void) 926 { 927 if (debug_stoppable) 928 debug_active = 0; 929 } 930 931 932 /* 933 * debug_event_common: 934 * - write debug entry with given size 935 */ 936 937 debug_entry_t* 938 debug_event_common(debug_info_t * id, int level, const void *buf, int len) 939 { 940 unsigned long flags; 941 debug_entry_t *active; 942 943 if (!debug_active || !id->areas) 944 return NULL; 945 spin_lock_irqsave(&id->lock, flags); 946 active = get_active_entry(id); 947 memset(DEBUG_DATA(active), 0, id->buf_size); 948 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 949 debug_finish_entry(id, active, level, 0); 950 spin_unlock_irqrestore(&id->lock, flags); 951 952 return active; 953 } 954 955 /* 956 * debug_exception_common: 957 * - write debug entry with given size and switch to next debug area 958 */ 959 960 debug_entry_t 961 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len) 962 { 963 unsigned long flags; 964 debug_entry_t *active; 965 966 if (!debug_active || !id->areas) 967 return NULL; 968 spin_lock_irqsave(&id->lock, flags); 969 active = get_active_entry(id); 970 memset(DEBUG_DATA(active), 0, id->buf_size); 971 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 972 debug_finish_entry(id, active, level, 1); 973 spin_unlock_irqrestore(&id->lock, flags); 974 975 return active; 976 } 977 978 /* 979 * counts arguments in format string for sprintf view 980 */ 981 982 static inline int 983 debug_count_numargs(char *string) 984 { 985 int numargs=0; 986 987 while(*string) { 988 if(*string++=='%') 989 numargs++; 990 } 991 return(numargs); 992 } 993 994 /* 995 * debug_sprintf_event: 996 */ 997 998 debug_entry_t* 999 debug_sprintf_event(debug_info_t* id, int level,char *string,...) 1000 { 1001 va_list ap; 1002 int numargs,idx; 1003 unsigned long flags; 1004 debug_sprintf_entry_t *curr_event; 1005 debug_entry_t *active; 1006 1007 if((!id) || (level > id->level)) 1008 return NULL; 1009 if (!debug_active || !id->areas) 1010 return NULL; 1011 numargs=debug_count_numargs(string); 1012 1013 spin_lock_irqsave(&id->lock, flags); 1014 active = get_active_entry(id); 1015 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active); 1016 va_start(ap,string); 1017 curr_event->string=string; 1018 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1019 curr_event->args[idx]=va_arg(ap,long); 1020 va_end(ap); 1021 debug_finish_entry(id, active, level, 0); 1022 spin_unlock_irqrestore(&id->lock, flags); 1023 1024 return active; 1025 } 1026 1027 /* 1028 * debug_sprintf_exception: 1029 */ 1030 1031 debug_entry_t* 1032 debug_sprintf_exception(debug_info_t* id, int level,char *string,...) 1033 { 1034 va_list ap; 1035 int numargs,idx; 1036 unsigned long flags; 1037 debug_sprintf_entry_t *curr_event; 1038 debug_entry_t *active; 1039 1040 if((!id) || (level > id->level)) 1041 return NULL; 1042 if (!debug_active || !id->areas) 1043 return NULL; 1044 1045 numargs=debug_count_numargs(string); 1046 1047 spin_lock_irqsave(&id->lock, flags); 1048 active = get_active_entry(id); 1049 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active); 1050 va_start(ap,string); 1051 curr_event->string=string; 1052 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1053 curr_event->args[idx]=va_arg(ap,long); 1054 va_end(ap); 1055 debug_finish_entry(id, active, level, 1); 1056 spin_unlock_irqrestore(&id->lock, flags); 1057 1058 return active; 1059 } 1060 1061 /* 1062 * debug_init: 1063 * - is called exactly once to initialize the debug feature 1064 */ 1065 1066 static int 1067 __init debug_init(void) 1068 { 1069 int rc = 0; 1070 1071 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1072 mutex_lock(&debug_mutex); 1073 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL); 1074 initialized = 1; 1075 mutex_unlock(&debug_mutex); 1076 1077 return rc; 1078 } 1079 1080 /* 1081 * debug_register_view: 1082 */ 1083 1084 int 1085 debug_register_view(debug_info_t * id, struct debug_view *view) 1086 { 1087 int rc = 0; 1088 int i; 1089 unsigned long flags; 1090 mode_t mode; 1091 struct dentry *pde; 1092 1093 if (!id) 1094 goto out; 1095 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1096 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1097 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1098 if (!view->input_proc) 1099 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1100 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1101 id , &debug_file_ops); 1102 if (!pde){ 1103 pr_err("Registering view %s/%s failed due to out of " 1104 "memory\n", id->name,view->name); 1105 rc = -1; 1106 goto out; 1107 } 1108 spin_lock_irqsave(&id->lock, flags); 1109 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1110 if (!id->views[i]) 1111 break; 1112 } 1113 if (i == DEBUG_MAX_VIEWS) { 1114 pr_err("Registering view %s/%s would exceed the maximum " 1115 "number of views %i\n", id->name, view->name, i); 1116 debugfs_remove(pde); 1117 rc = -1; 1118 } else { 1119 id->views[i] = view; 1120 id->debugfs_entries[i] = pde; 1121 } 1122 spin_unlock_irqrestore(&id->lock, flags); 1123 out: 1124 return rc; 1125 } 1126 1127 /* 1128 * debug_unregister_view: 1129 */ 1130 1131 int 1132 debug_unregister_view(debug_info_t * id, struct debug_view *view) 1133 { 1134 int rc = 0; 1135 int i; 1136 unsigned long flags; 1137 1138 if (!id) 1139 goto out; 1140 spin_lock_irqsave(&id->lock, flags); 1141 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1142 if (id->views[i] == view) 1143 break; 1144 } 1145 if (i == DEBUG_MAX_VIEWS) 1146 rc = -1; 1147 else { 1148 debugfs_remove(id->debugfs_entries[i]); 1149 id->views[i] = NULL; 1150 } 1151 spin_unlock_irqrestore(&id->lock, flags); 1152 out: 1153 return rc; 1154 } 1155 1156 static inline char * 1157 debug_get_user_string(const char __user *user_buf, size_t user_len) 1158 { 1159 char* buffer; 1160 1161 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1162 if (!buffer) 1163 return ERR_PTR(-ENOMEM); 1164 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1165 kfree(buffer); 1166 return ERR_PTR(-EFAULT); 1167 } 1168 /* got the string, now strip linefeed. */ 1169 if (buffer[user_len - 1] == '\n') 1170 buffer[user_len - 1] = 0; 1171 else 1172 buffer[user_len] = 0; 1173 return buffer; 1174 } 1175 1176 static inline int 1177 debug_get_uint(char *buf) 1178 { 1179 int rc; 1180 1181 for(; isspace(*buf); buf++); 1182 rc = simple_strtoul(buf, &buf, 10); 1183 if(*buf){ 1184 rc = -EINVAL; 1185 } 1186 return rc; 1187 } 1188 1189 /* 1190 * functions for debug-views 1191 *********************************** 1192 */ 1193 1194 /* 1195 * prints out actual debug level 1196 */ 1197 1198 static int 1199 debug_prolog_pages_fn(debug_info_t * id, 1200 struct debug_view *view, char *out_buf) 1201 { 1202 return sprintf(out_buf, "%i\n", id->pages_per_area); 1203 } 1204 1205 /* 1206 * reads new size (number of pages per debug area) 1207 */ 1208 1209 static int 1210 debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 1211 struct file *file, const char __user *user_buf, 1212 size_t user_len, loff_t * offset) 1213 { 1214 char *str; 1215 int rc,new_pages; 1216 1217 if (user_len > 0x10000) 1218 user_len = 0x10000; 1219 if (*offset != 0){ 1220 rc = -EPIPE; 1221 goto out; 1222 } 1223 str = debug_get_user_string(user_buf,user_len); 1224 if(IS_ERR(str)){ 1225 rc = PTR_ERR(str); 1226 goto out; 1227 } 1228 new_pages = debug_get_uint(str); 1229 if(new_pages < 0){ 1230 rc = -EINVAL; 1231 goto free_str; 1232 } 1233 rc = debug_set_size(id,id->nr_areas, new_pages); 1234 if(rc != 0){ 1235 rc = -EINVAL; 1236 goto free_str; 1237 } 1238 rc = user_len; 1239 free_str: 1240 kfree(str); 1241 out: 1242 *offset += user_len; 1243 return rc; /* number of input characters */ 1244 } 1245 1246 /* 1247 * prints out actual debug level 1248 */ 1249 1250 static int 1251 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf) 1252 { 1253 int rc = 0; 1254 1255 if(id->level == DEBUG_OFF_LEVEL) { 1256 rc = sprintf(out_buf,"-\n"); 1257 } 1258 else { 1259 rc = sprintf(out_buf, "%i\n", id->level); 1260 } 1261 return rc; 1262 } 1263 1264 /* 1265 * reads new debug level 1266 */ 1267 1268 static int 1269 debug_input_level_fn(debug_info_t * id, struct debug_view *view, 1270 struct file *file, const char __user *user_buf, 1271 size_t user_len, loff_t * offset) 1272 { 1273 char *str; 1274 int rc,new_level; 1275 1276 if (user_len > 0x10000) 1277 user_len = 0x10000; 1278 if (*offset != 0){ 1279 rc = -EPIPE; 1280 goto out; 1281 } 1282 str = debug_get_user_string(user_buf,user_len); 1283 if(IS_ERR(str)){ 1284 rc = PTR_ERR(str); 1285 goto out; 1286 } 1287 if(str[0] == '-'){ 1288 debug_set_level(id, DEBUG_OFF_LEVEL); 1289 rc = user_len; 1290 goto free_str; 1291 } else { 1292 new_level = debug_get_uint(str); 1293 } 1294 if(new_level < 0) { 1295 pr_warning("%s is not a valid level for a debug " 1296 "feature\n", str); 1297 rc = -EINVAL; 1298 } else { 1299 debug_set_level(id, new_level); 1300 rc = user_len; 1301 } 1302 free_str: 1303 kfree(str); 1304 out: 1305 *offset += user_len; 1306 return rc; /* number of input characters */ 1307 } 1308 1309 1310 /* 1311 * flushes debug areas 1312 */ 1313 1314 static void debug_flush(debug_info_t* id, int area) 1315 { 1316 unsigned long flags; 1317 int i,j; 1318 1319 if(!id || !id->areas) 1320 return; 1321 spin_lock_irqsave(&id->lock,flags); 1322 if(area == DEBUG_FLUSH_ALL){ 1323 id->active_area = 0; 1324 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1325 for (i = 0; i < id->nr_areas; i++) { 1326 id->active_pages[i] = 0; 1327 for(j = 0; j < id->pages_per_area; j++) { 1328 memset(id->areas[i][j], 0, PAGE_SIZE); 1329 } 1330 } 1331 } else if(area >= 0 && area < id->nr_areas) { 1332 id->active_entries[area] = 0; 1333 id->active_pages[area] = 0; 1334 for(i = 0; i < id->pages_per_area; i++) { 1335 memset(id->areas[area][i],0,PAGE_SIZE); 1336 } 1337 } 1338 spin_unlock_irqrestore(&id->lock,flags); 1339 } 1340 1341 /* 1342 * view function: flushes debug areas 1343 */ 1344 1345 static int 1346 debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 1347 struct file *file, const char __user *user_buf, 1348 size_t user_len, loff_t * offset) 1349 { 1350 char input_buf[1]; 1351 int rc = user_len; 1352 1353 if (user_len > 0x10000) 1354 user_len = 0x10000; 1355 if (*offset != 0){ 1356 rc = -EPIPE; 1357 goto out; 1358 } 1359 if (copy_from_user(input_buf, user_buf, 1)){ 1360 rc = -EFAULT; 1361 goto out; 1362 } 1363 if(input_buf[0] == '-') { 1364 debug_flush(id, DEBUG_FLUSH_ALL); 1365 goto out; 1366 } 1367 if (isdigit(input_buf[0])) { 1368 int area = ((int) input_buf[0] - (int) '0'); 1369 debug_flush(id, area); 1370 goto out; 1371 } 1372 1373 pr_info("Flushing debug data failed because %c is not a valid " 1374 "area\n", input_buf[0]); 1375 1376 out: 1377 *offset += user_len; 1378 return rc; /* number of input characters */ 1379 } 1380 1381 /* 1382 * prints debug header in raw format 1383 */ 1384 1385 static int 1386 debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 1387 int area, debug_entry_t * entry, char *out_buf) 1388 { 1389 int rc; 1390 1391 rc = sizeof(debug_entry_t); 1392 memcpy(out_buf,entry,sizeof(debug_entry_t)); 1393 return rc; 1394 } 1395 1396 /* 1397 * prints debug data in raw format 1398 */ 1399 1400 static int 1401 debug_raw_format_fn(debug_info_t * id, struct debug_view *view, 1402 char *out_buf, const char *in_buf) 1403 { 1404 int rc; 1405 1406 rc = id->buf_size; 1407 memcpy(out_buf, in_buf, id->buf_size); 1408 return rc; 1409 } 1410 1411 /* 1412 * prints debug data in hex/ascii format 1413 */ 1414 1415 static int 1416 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 1417 char *out_buf, const char *in_buf) 1418 { 1419 int i, rc = 0; 1420 1421 for (i = 0; i < id->buf_size; i++) { 1422 rc += sprintf(out_buf + rc, "%02x ", 1423 ((unsigned char *) in_buf)[i]); 1424 } 1425 rc += sprintf(out_buf + rc, "| "); 1426 for (i = 0; i < id->buf_size; i++) { 1427 unsigned char c = in_buf[i]; 1428 if (!isprint(c)) 1429 rc += sprintf(out_buf + rc, "."); 1430 else 1431 rc += sprintf(out_buf + rc, "%c", c); 1432 } 1433 rc += sprintf(out_buf + rc, "\n"); 1434 return rc; 1435 } 1436 1437 /* 1438 * prints header for debug entry 1439 */ 1440 1441 int 1442 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view, 1443 int area, debug_entry_t * entry, char *out_buf) 1444 { 1445 struct timespec time_spec; 1446 char *except_str; 1447 unsigned long caller; 1448 int rc = 0; 1449 unsigned int level; 1450 1451 level = entry->id.fields.level; 1452 stck_to_timespec(entry->id.stck, &time_spec); 1453 1454 if (entry->id.fields.exception) 1455 except_str = "*"; 1456 else 1457 except_str = "-"; 1458 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN; 1459 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ", 1460 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level, 1461 except_str, entry->id.fields.cpuid, (void *) caller); 1462 return rc; 1463 } 1464 1465 /* 1466 * prints debug data sprintf-formated: 1467 * debug_sprinf_event/exception calls must be used together with this view 1468 */ 1469 1470 #define DEBUG_SPRINTF_MAX_ARGS 10 1471 1472 static int 1473 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 1474 char *out_buf, debug_sprintf_entry_t *curr_event) 1475 { 1476 int num_longs, num_used_args = 0,i, rc = 0; 1477 int index[DEBUG_SPRINTF_MAX_ARGS]; 1478 1479 /* count of longs fit into one entry */ 1480 num_longs = id->buf_size / sizeof(long); 1481 1482 if(num_longs < 1) 1483 goto out; /* bufsize of entry too small */ 1484 if(num_longs == 1) { 1485 /* no args, we use only the string */ 1486 strcpy(out_buf, curr_event->string); 1487 rc = strlen(curr_event->string); 1488 goto out; 1489 } 1490 1491 /* number of arguments used for sprintf (without the format string) */ 1492 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1493 1494 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1495 1496 for(i = 0; i < num_used_args; i++) 1497 index[i] = i; 1498 1499 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1500 curr_event->args[index[1]], curr_event->args[index[2]], 1501 curr_event->args[index[3]], curr_event->args[index[4]], 1502 curr_event->args[index[5]], curr_event->args[index[6]], 1503 curr_event->args[index[7]], curr_event->args[index[8]], 1504 curr_event->args[index[9]]); 1505 1506 out: 1507 1508 return rc; 1509 } 1510 1511 /* 1512 * clean up module 1513 */ 1514 static void __exit debug_exit(void) 1515 { 1516 debugfs_remove(debug_debugfs_root_entry); 1517 unregister_sysctl_table(s390dbf_sysctl_header); 1518 return; 1519 } 1520 1521 /* 1522 * module definitions 1523 */ 1524 postcore_initcall(debug_init); 1525 module_exit(debug_exit); 1526 MODULE_LICENSE("GPL"); 1527 1528 EXPORT_SYMBOL(debug_register); 1529 EXPORT_SYMBOL(debug_unregister); 1530 EXPORT_SYMBOL(debug_set_level); 1531 EXPORT_SYMBOL(debug_stop_all); 1532 EXPORT_SYMBOL(debug_register_view); 1533 EXPORT_SYMBOL(debug_unregister_view); 1534 EXPORT_SYMBOL(debug_event_common); 1535 EXPORT_SYMBOL(debug_exception_common); 1536 EXPORT_SYMBOL(debug_hex_ascii_view); 1537 EXPORT_SYMBOL(debug_raw_view); 1538 EXPORT_SYMBOL(debug_dflt_header_fn); 1539 EXPORT_SYMBOL(debug_sprintf_view); 1540 EXPORT_SYMBOL(debug_sprintf_exception); 1541 EXPORT_SYMBOL(debug_sprintf_event); 1542