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