1 /* 2 * S/390 debug facility 3 * 4 * Copyright IBM Corp. 1999, 2012 5 * 6 * Author(s): Michael Holzheu (holzheu@de.ibm.com), 7 * Holger Smolinski (Holger.Smolinski@de.ibm.com) 8 * 9 * Bugreports to: <Linux390@de.ibm.com> 10 */ 11 12 #define KMSG_COMPONENT "s390dbf" 13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 14 15 #include <linux/stddef.h> 16 #include <linux/kernel.h> 17 #include <linux/errno.h> 18 #include <linux/slab.h> 19 #include <linux/ctype.h> 20 #include <linux/string.h> 21 #include <linux/sysctl.h> 22 #include <linux/uaccess.h> 23 #include <linux/export.h> 24 #include <linux/init.h> 25 #include <linux/fs.h> 26 #include <linux/debugfs.h> 27 28 #include <asm/debug.h> 29 30 #define DEBUG_PROLOG_ENTRY -1 31 32 #define ALL_AREAS 0 /* copy all debug areas */ 33 #define NO_AREAS 1 /* copy no debug areas */ 34 35 /* typedefs */ 36 37 typedef struct file_private_info { 38 loff_t offset; /* offset of last read in file */ 39 int act_area; /* number of last formated area */ 40 int act_page; /* act page in given area */ 41 int act_entry; /* last formated entry (offset */ 42 /* relative to beginning of last */ 43 /* formated page) */ 44 size_t act_entry_offset; /* up to this offset we copied */ 45 /* in last read the last formated */ 46 /* entry to userland */ 47 char temp_buf[2048]; /* buffer for output */ 48 debug_info_t *debug_info_org; /* original debug information */ 49 debug_info_t *debug_info_snap; /* snapshot of debug information */ 50 struct debug_view *view; /* used view of debug info */ 51 } file_private_info_t; 52 53 typedef struct 54 { 55 char *string; 56 /* 57 * This assumes that all args are converted into longs 58 * on L/390 this is the case for all types of parameter 59 * except of floats, and long long (32 bit) 60 * 61 */ 62 long args[0]; 63 } debug_sprintf_entry_t; 64 65 66 /* internal function prototyes */ 67 68 static int debug_init(void); 69 static ssize_t debug_output(struct file *file, char __user *user_buf, 70 size_t user_len, loff_t * offset); 71 static ssize_t debug_input(struct file *file, const char __user *user_buf, 72 size_t user_len, loff_t * offset); 73 static int debug_open(struct inode *inode, struct file *file); 74 static int debug_close(struct inode *inode, struct file *file); 75 static debug_info_t *debug_info_create(const char *name, int pages_per_area, 76 int nr_areas, int buf_size, umode_t mode); 77 static void debug_info_get(debug_info_t *); 78 static void debug_info_put(debug_info_t *); 79 static int debug_prolog_level_fn(debug_info_t * id, 80 struct debug_view *view, char *out_buf); 81 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view, 82 struct file *file, const char __user *user_buf, 83 size_t user_buf_size, loff_t * offset); 84 static int debug_prolog_pages_fn(debug_info_t * id, 85 struct debug_view *view, char *out_buf); 86 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 87 struct file *file, const char __user *user_buf, 88 size_t user_buf_size, loff_t * offset); 89 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 90 struct file *file, const char __user *user_buf, 91 size_t user_buf_size, loff_t * offset); 92 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 93 char *out_buf, const char *in_buf); 94 static int debug_raw_format_fn(debug_info_t * id, 95 struct debug_view *view, char *out_buf, 96 const char *in_buf); 97 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 98 int area, debug_entry_t * entry, char *out_buf); 99 100 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 101 char *out_buf, debug_sprintf_entry_t *curr_event); 102 103 /* globals */ 104 105 struct debug_view debug_raw_view = { 106 "raw", 107 NULL, 108 &debug_raw_header_fn, 109 &debug_raw_format_fn, 110 NULL, 111 NULL 112 }; 113 EXPORT_SYMBOL(debug_raw_view); 114 115 struct debug_view debug_hex_ascii_view = { 116 "hex_ascii", 117 NULL, 118 &debug_dflt_header_fn, 119 &debug_hex_ascii_format_fn, 120 NULL, 121 NULL 122 }; 123 EXPORT_SYMBOL(debug_hex_ascii_view); 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 EXPORT_SYMBOL(debug_sprintf_view); 161 162 /* used by dump analysis tools to determine version of debug feature */ 163 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 164 165 /* static globals */ 166 167 static debug_info_t *debug_area_first = NULL; 168 static debug_info_t *debug_area_last = NULL; 169 static DEFINE_MUTEX(debug_mutex); 170 171 static int initialized; 172 static int debug_critical; 173 174 static const struct file_operations debug_file_ops = { 175 .owner = THIS_MODULE, 176 .read = debug_output, 177 .write = debug_input, 178 .open = debug_open, 179 .release = debug_close, 180 .llseek = no_llseek, 181 }; 182 183 static struct dentry *debug_debugfs_root_entry; 184 185 /* functions */ 186 187 /* 188 * debug_areas_alloc 189 * - Debug areas are implemented as a threedimensonal array: 190 * areas[areanumber][pagenumber][pageoffset] 191 */ 192 193 static debug_entry_t*** 194 debug_areas_alloc(int pages_per_area, int nr_areas) 195 { 196 debug_entry_t*** areas; 197 int i,j; 198 199 areas = kmalloc(nr_areas * 200 sizeof(debug_entry_t**), 201 GFP_KERNEL); 202 if (!areas) 203 goto fail_malloc_areas; 204 for (i = 0; i < nr_areas; i++) { 205 areas[i] = kmalloc(pages_per_area * 206 sizeof(debug_entry_t*),GFP_KERNEL); 207 if (!areas[i]) { 208 goto fail_malloc_areas2; 209 } 210 for(j = 0; j < pages_per_area; j++) { 211 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); 212 if(!areas[i][j]) { 213 for(j--; j >=0 ; j--) { 214 kfree(areas[i][j]); 215 } 216 kfree(areas[i]); 217 goto fail_malloc_areas2; 218 } 219 } 220 } 221 return areas; 222 223 fail_malloc_areas2: 224 for(i--; i >= 0; i--){ 225 for(j=0; j < pages_per_area;j++){ 226 kfree(areas[i][j]); 227 } 228 kfree(areas[i]); 229 } 230 kfree(areas); 231 fail_malloc_areas: 232 return NULL; 233 234 } 235 236 237 /* 238 * debug_info_alloc 239 * - alloc new debug-info 240 */ 241 242 static debug_info_t* 243 debug_info_alloc(const char *name, int pages_per_area, int nr_areas, 244 int buf_size, int level, int mode) 245 { 246 debug_info_t* rc; 247 248 /* alloc everything */ 249 250 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); 251 if(!rc) 252 goto fail_malloc_rc; 253 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 254 if(!rc->active_entries) 255 goto fail_malloc_active_entries; 256 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 257 if(!rc->active_pages) 258 goto fail_malloc_active_pages; 259 if((mode == ALL_AREAS) && (pages_per_area != 0)){ 260 rc->areas = debug_areas_alloc(pages_per_area, nr_areas); 261 if(!rc->areas) 262 goto fail_malloc_areas; 263 } else { 264 rc->areas = NULL; 265 } 266 267 /* initialize members */ 268 269 spin_lock_init(&rc->lock); 270 rc->pages_per_area = pages_per_area; 271 rc->nr_areas = nr_areas; 272 rc->active_area = 0; 273 rc->level = level; 274 rc->buf_size = buf_size; 275 rc->entry_size = sizeof(debug_entry_t) + buf_size; 276 strlcpy(rc->name, name, sizeof(rc->name)); 277 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); 278 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS * 279 sizeof(struct dentry*)); 280 refcount_set(&(rc->ref_count), 0); 281 282 return rc; 283 284 fail_malloc_areas: 285 kfree(rc->active_pages); 286 fail_malloc_active_pages: 287 kfree(rc->active_entries); 288 fail_malloc_active_entries: 289 kfree(rc); 290 fail_malloc_rc: 291 return NULL; 292 } 293 294 /* 295 * debug_areas_free 296 * - free all debug areas 297 */ 298 299 static void 300 debug_areas_free(debug_info_t* db_info) 301 { 302 int i,j; 303 304 if(!db_info->areas) 305 return; 306 for (i = 0; i < db_info->nr_areas; i++) { 307 for(j = 0; j < db_info->pages_per_area; j++) { 308 kfree(db_info->areas[i][j]); 309 } 310 kfree(db_info->areas[i]); 311 } 312 kfree(db_info->areas); 313 db_info->areas = NULL; 314 } 315 316 /* 317 * debug_info_free 318 * - free memory debug-info 319 */ 320 321 static void 322 debug_info_free(debug_info_t* db_info){ 323 debug_areas_free(db_info); 324 kfree(db_info->active_entries); 325 kfree(db_info->active_pages); 326 kfree(db_info); 327 } 328 329 /* 330 * debug_info_create 331 * - create new debug-info 332 */ 333 334 static debug_info_t* 335 debug_info_create(const char *name, int pages_per_area, int nr_areas, 336 int buf_size, umode_t mode) 337 { 338 debug_info_t* rc; 339 340 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, 341 DEBUG_DEFAULT_LEVEL, ALL_AREAS); 342 if(!rc) 343 goto out; 344 345 rc->mode = mode & ~S_IFMT; 346 347 /* create root directory */ 348 rc->debugfs_root_entry = debugfs_create_dir(rc->name, 349 debug_debugfs_root_entry); 350 351 /* append new element to linked list */ 352 if (!debug_area_first) { 353 /* first element in list */ 354 debug_area_first = rc; 355 rc->prev = NULL; 356 } else { 357 /* append element to end of list */ 358 debug_area_last->next = rc; 359 rc->prev = debug_area_last; 360 } 361 debug_area_last = rc; 362 rc->next = NULL; 363 364 refcount_set(&rc->ref_count, 1); 365 out: 366 return rc; 367 } 368 369 /* 370 * debug_info_copy 371 * - copy debug-info 372 */ 373 374 static debug_info_t* 375 debug_info_copy(debug_info_t* in, int mode) 376 { 377 int i,j; 378 debug_info_t* rc; 379 unsigned long flags; 380 381 /* get a consistent copy of the debug areas */ 382 do { 383 rc = debug_info_alloc(in->name, in->pages_per_area, 384 in->nr_areas, in->buf_size, in->level, mode); 385 spin_lock_irqsave(&in->lock, flags); 386 if(!rc) 387 goto out; 388 /* has something changed in the meantime ? */ 389 if((rc->pages_per_area == in->pages_per_area) && 390 (rc->nr_areas == in->nr_areas)) { 391 break; 392 } 393 spin_unlock_irqrestore(&in->lock, flags); 394 debug_info_free(rc); 395 } while (1); 396 397 if (mode == NO_AREAS) 398 goto out; 399 400 for(i = 0; i < in->nr_areas; i++){ 401 for(j = 0; j < in->pages_per_area; j++) { 402 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE); 403 } 404 } 405 out: 406 spin_unlock_irqrestore(&in->lock, flags); 407 return rc; 408 } 409 410 /* 411 * debug_info_get 412 * - increments reference count for debug-info 413 */ 414 415 static void 416 debug_info_get(debug_info_t * db_info) 417 { 418 if (db_info) 419 refcount_inc(&db_info->ref_count); 420 } 421 422 /* 423 * debug_info_put: 424 * - decreases reference count for debug-info and frees it if necessary 425 */ 426 427 static void 428 debug_info_put(debug_info_t *db_info) 429 { 430 int i; 431 432 if (!db_info) 433 return; 434 if (refcount_dec_and_test(&db_info->ref_count)) { 435 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 436 if (!db_info->views[i]) 437 continue; 438 debugfs_remove(db_info->debugfs_entries[i]); 439 } 440 debugfs_remove(db_info->debugfs_root_entry); 441 if(db_info == debug_area_first) 442 debug_area_first = db_info->next; 443 if(db_info == debug_area_last) 444 debug_area_last = db_info->prev; 445 if(db_info->prev) db_info->prev->next = db_info->next; 446 if(db_info->next) db_info->next->prev = db_info->prev; 447 debug_info_free(db_info); 448 } 449 } 450 451 /* 452 * debug_format_entry: 453 * - format one debug entry and return size of formated data 454 */ 455 456 static int 457 debug_format_entry(file_private_info_t *p_info) 458 { 459 debug_info_t *id_snap = p_info->debug_info_snap; 460 struct debug_view *view = p_info->view; 461 debug_entry_t *act_entry; 462 size_t len = 0; 463 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 464 /* print prolog */ 465 if (view->prolog_proc) 466 len += view->prolog_proc(id_snap,view,p_info->temp_buf); 467 goto out; 468 } 469 if (!id_snap->areas) /* this is true, if we have a prolog only view */ 470 goto out; /* or if 'pages_per_area' is 0 */ 471 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area] 472 [p_info->act_page] + p_info->act_entry); 473 474 if (act_entry->id.stck == 0LL) 475 goto out; /* empty entry */ 476 if (view->header_proc) 477 len += view->header_proc(id_snap, view, p_info->act_area, 478 act_entry, p_info->temp_buf + len); 479 if (view->format_proc) 480 len += view->format_proc(id_snap, view, p_info->temp_buf + len, 481 DEBUG_DATA(act_entry)); 482 out: 483 return len; 484 } 485 486 /* 487 * debug_next_entry: 488 * - goto next entry in p_info 489 */ 490 491 static inline int 492 debug_next_entry(file_private_info_t *p_info) 493 { 494 debug_info_t *id; 495 496 id = p_info->debug_info_snap; 497 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 498 p_info->act_entry = 0; 499 p_info->act_page = 0; 500 goto out; 501 } 502 if(!id->areas) 503 return 1; 504 p_info->act_entry += id->entry_size; 505 /* switch to next page, if we reached the end of the page */ 506 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){ 507 /* next page */ 508 p_info->act_entry = 0; 509 p_info->act_page += 1; 510 if((p_info->act_page % id->pages_per_area) == 0) { 511 /* next area */ 512 p_info->act_area++; 513 p_info->act_page=0; 514 } 515 if(p_info->act_area >= id->nr_areas) 516 return 1; 517 } 518 out: 519 return 0; 520 } 521 522 /* 523 * debug_output: 524 * - called for user read() 525 * - copies formated debug entries to the user buffer 526 */ 527 528 static ssize_t 529 debug_output(struct file *file, /* file descriptor */ 530 char __user *user_buf, /* user buffer */ 531 size_t len, /* length of buffer */ 532 loff_t *offset) /* offset in the file */ 533 { 534 size_t count = 0; 535 size_t entry_offset; 536 file_private_info_t *p_info; 537 538 p_info = ((file_private_info_t *) file->private_data); 539 if (*offset != p_info->offset) 540 return -EPIPE; 541 if(p_info->act_area >= p_info->debug_info_snap->nr_areas) 542 return 0; 543 entry_offset = p_info->act_entry_offset; 544 while(count < len){ 545 int formatted_line_size; 546 int formatted_line_residue; 547 int user_buf_residue; 548 size_t copy_size; 549 550 formatted_line_size = debug_format_entry(p_info); 551 formatted_line_residue = formatted_line_size - entry_offset; 552 user_buf_residue = len-count; 553 copy_size = min(user_buf_residue, formatted_line_residue); 554 if(copy_size){ 555 if (copy_to_user(user_buf + count, p_info->temp_buf 556 + entry_offset, copy_size)) 557 return -EFAULT; 558 count += copy_size; 559 entry_offset += copy_size; 560 } 561 if(copy_size == formatted_line_residue){ 562 entry_offset = 0; 563 if(debug_next_entry(p_info)) 564 goto out; 565 } 566 } 567 out: 568 p_info->offset = *offset + count; 569 p_info->act_entry_offset = entry_offset; 570 *offset = p_info->offset; 571 return count; 572 } 573 574 /* 575 * debug_input: 576 * - called for user write() 577 * - calls input function of view 578 */ 579 580 static ssize_t 581 debug_input(struct file *file, const char __user *user_buf, size_t length, 582 loff_t *offset) 583 { 584 int rc = 0; 585 file_private_info_t *p_info; 586 587 mutex_lock(&debug_mutex); 588 p_info = ((file_private_info_t *) file->private_data); 589 if (p_info->view->input_proc) 590 rc = p_info->view->input_proc(p_info->debug_info_org, 591 p_info->view, file, user_buf, 592 length, offset); 593 else 594 rc = -EPERM; 595 mutex_unlock(&debug_mutex); 596 return rc; /* number of input characters */ 597 } 598 599 /* 600 * debug_open: 601 * - called for user open() 602 * - copies formated output to private_data area of the file 603 * handle 604 */ 605 606 static int 607 debug_open(struct inode *inode, struct file *file) 608 { 609 int i, rc = 0; 610 file_private_info_t *p_info; 611 debug_info_t *debug_info, *debug_info_snapshot; 612 613 mutex_lock(&debug_mutex); 614 debug_info = file_inode(file)->i_private; 615 /* find debug view */ 616 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 617 if (!debug_info->views[i]) 618 continue; 619 else if (debug_info->debugfs_entries[i] == 620 file->f_path.dentry) { 621 goto found; /* found view ! */ 622 } 623 } 624 /* no entry found */ 625 rc = -EINVAL; 626 goto out; 627 628 found: 629 630 /* Make snapshot of current debug areas to get it consistent. */ 631 /* To copy all the areas is only needed, if we have a view which */ 632 /* formats the debug areas. */ 633 634 if(!debug_info->views[i]->format_proc && 635 !debug_info->views[i]->header_proc){ 636 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS); 637 } else { 638 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS); 639 } 640 641 if(!debug_info_snapshot){ 642 rc = -ENOMEM; 643 goto out; 644 } 645 p_info = kmalloc(sizeof(file_private_info_t), 646 GFP_KERNEL); 647 if(!p_info){ 648 debug_info_free(debug_info_snapshot); 649 rc = -ENOMEM; 650 goto out; 651 } 652 p_info->offset = 0; 653 p_info->debug_info_snap = debug_info_snapshot; 654 p_info->debug_info_org = debug_info; 655 p_info->view = debug_info->views[i]; 656 p_info->act_area = 0; 657 p_info->act_page = 0; 658 p_info->act_entry = DEBUG_PROLOG_ENTRY; 659 p_info->act_entry_offset = 0; 660 file->private_data = p_info; 661 debug_info_get(debug_info); 662 nonseekable_open(inode, file); 663 out: 664 mutex_unlock(&debug_mutex); 665 return rc; 666 } 667 668 /* 669 * debug_close: 670 * - called for user close() 671 * - deletes private_data area of the file handle 672 */ 673 674 static int 675 debug_close(struct inode *inode, struct file *file) 676 { 677 file_private_info_t *p_info; 678 p_info = (file_private_info_t *) file->private_data; 679 if(p_info->debug_info_snap) 680 debug_info_free(p_info->debug_info_snap); 681 debug_info_put(p_info->debug_info_org); 682 kfree(file->private_data); 683 return 0; /* success */ 684 } 685 686 /* 687 * debug_register_mode: 688 * - Creates and initializes debug area for the caller 689 * The mode parameter allows to specify access rights for the s390dbf files 690 * - Returns handle for debug area 691 */ 692 693 debug_info_t *debug_register_mode(const char *name, int pages_per_area, 694 int nr_areas, int buf_size, umode_t mode, 695 uid_t uid, gid_t gid) 696 { 697 debug_info_t *rc = NULL; 698 699 /* Since debugfs currently does not support uid/gid other than root, */ 700 /* we do not allow gid/uid != 0 until we get support for that. */ 701 if ((uid != 0) || (gid != 0)) 702 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n"); 703 BUG_ON(!initialized); 704 mutex_lock(&debug_mutex); 705 706 /* create new debug_info */ 707 708 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 709 if(!rc) 710 goto out; 711 debug_register_view(rc, &debug_level_view); 712 debug_register_view(rc, &debug_flush_view); 713 debug_register_view(rc, &debug_pages_view); 714 out: 715 if (!rc){ 716 pr_err("Registering debug feature %s failed\n", name); 717 } 718 mutex_unlock(&debug_mutex); 719 return rc; 720 } 721 EXPORT_SYMBOL(debug_register_mode); 722 723 /* 724 * debug_register: 725 * - creates and initializes debug area for the caller 726 * - returns handle for debug area 727 */ 728 729 debug_info_t *debug_register(const char *name, int pages_per_area, 730 int nr_areas, int buf_size) 731 { 732 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 733 S_IRUSR | S_IWUSR, 0, 0); 734 } 735 EXPORT_SYMBOL(debug_register); 736 737 /* 738 * debug_unregister: 739 * - give back debug area 740 */ 741 742 void 743 debug_unregister(debug_info_t * id) 744 { 745 if (!id) 746 goto out; 747 mutex_lock(&debug_mutex); 748 debug_info_put(id); 749 mutex_unlock(&debug_mutex); 750 751 out: 752 return; 753 } 754 EXPORT_SYMBOL(debug_unregister); 755 756 /* 757 * debug_set_size: 758 * - set area size (number of pages) and number of areas 759 */ 760 static int 761 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area) 762 { 763 unsigned long flags; 764 debug_entry_t *** new_areas; 765 int rc=0; 766 767 if(!id || (nr_areas <= 0) || (pages_per_area < 0)) 768 return -EINVAL; 769 if(pages_per_area > 0){ 770 new_areas = debug_areas_alloc(pages_per_area, nr_areas); 771 if(!new_areas) { 772 pr_info("Allocating memory for %i pages failed\n", 773 pages_per_area); 774 rc = -ENOMEM; 775 goto out; 776 } 777 } else { 778 new_areas = NULL; 779 } 780 spin_lock_irqsave(&id->lock,flags); 781 debug_areas_free(id); 782 id->areas = new_areas; 783 id->nr_areas = nr_areas; 784 id->pages_per_area = pages_per_area; 785 id->active_area = 0; 786 memset(id->active_entries,0,sizeof(int)*id->nr_areas); 787 memset(id->active_pages, 0, sizeof(int)*id->nr_areas); 788 spin_unlock_irqrestore(&id->lock,flags); 789 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area); 790 out: 791 return rc; 792 } 793 794 /* 795 * debug_set_level: 796 * - set actual debug level 797 */ 798 799 void 800 debug_set_level(debug_info_t* id, int new_level) 801 { 802 unsigned long flags; 803 if(!id) 804 return; 805 spin_lock_irqsave(&id->lock,flags); 806 if(new_level == DEBUG_OFF_LEVEL){ 807 id->level = DEBUG_OFF_LEVEL; 808 pr_info("%s: switched off\n",id->name); 809 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 810 pr_info("%s: level %i is out of range (%i - %i)\n", 811 id->name, new_level, 0, DEBUG_MAX_LEVEL); 812 } else { 813 id->level = new_level; 814 } 815 spin_unlock_irqrestore(&id->lock,flags); 816 } 817 EXPORT_SYMBOL(debug_set_level); 818 819 /* 820 * proceed_active_entry: 821 * - set active entry to next in the ring buffer 822 */ 823 824 static inline void 825 proceed_active_entry(debug_info_t * id) 826 { 827 if ((id->active_entries[id->active_area] += id->entry_size) 828 > (PAGE_SIZE - id->entry_size)){ 829 id->active_entries[id->active_area] = 0; 830 id->active_pages[id->active_area] = 831 (id->active_pages[id->active_area] + 1) % 832 id->pages_per_area; 833 } 834 } 835 836 /* 837 * proceed_active_area: 838 * - set active area to next in the ring buffer 839 */ 840 841 static inline void 842 proceed_active_area(debug_info_t * id) 843 { 844 id->active_area++; 845 id->active_area = id->active_area % id->nr_areas; 846 } 847 848 /* 849 * get_active_entry: 850 */ 851 852 static inline debug_entry_t* 853 get_active_entry(debug_info_t * id) 854 { 855 return (debug_entry_t *) (((char *) id->areas[id->active_area] 856 [id->active_pages[id->active_area]]) + 857 id->active_entries[id->active_area]); 858 } 859 860 /* 861 * debug_finish_entry: 862 * - set timestamp, caller address, cpu number etc. 863 */ 864 865 static inline void 866 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level, 867 int exception) 868 { 869 active->id.stck = get_tod_clock_fast() - 870 *(unsigned long long *) &tod_clock_base[1]; 871 active->id.fields.cpuid = smp_processor_id(); 872 active->caller = __builtin_return_address(0); 873 active->id.fields.exception = exception; 874 active->id.fields.level = level; 875 proceed_active_entry(id); 876 if(exception) 877 proceed_active_area(id); 878 } 879 880 static int debug_stoppable=1; 881 static int debug_active=1; 882 883 #define CTL_S390DBF_STOPPABLE 5678 884 #define CTL_S390DBF_ACTIVE 5679 885 886 /* 887 * proc handler for the running debug_active sysctl 888 * always allow read, allow write only if debug_stoppable is set or 889 * if debug_active is already off 890 */ 891 static int 892 s390dbf_procactive(struct ctl_table *table, int write, 893 void __user *buffer, size_t *lenp, loff_t *ppos) 894 { 895 if (!write || debug_stoppable || !debug_active) 896 return proc_dointvec(table, write, buffer, lenp, ppos); 897 else 898 return 0; 899 } 900 901 902 static struct ctl_table s390dbf_table[] = { 903 { 904 .procname = "debug_stoppable", 905 .data = &debug_stoppable, 906 .maxlen = sizeof(int), 907 .mode = S_IRUGO | S_IWUSR, 908 .proc_handler = proc_dointvec, 909 }, 910 { 911 .procname = "debug_active", 912 .data = &debug_active, 913 .maxlen = sizeof(int), 914 .mode = S_IRUGO | S_IWUSR, 915 .proc_handler = s390dbf_procactive, 916 }, 917 { } 918 }; 919 920 static struct ctl_table s390dbf_dir_table[] = { 921 { 922 .procname = "s390dbf", 923 .maxlen = 0, 924 .mode = S_IRUGO | S_IXUGO, 925 .child = s390dbf_table, 926 }, 927 { } 928 }; 929 930 static struct ctl_table_header *s390dbf_sysctl_header; 931 932 void 933 debug_stop_all(void) 934 { 935 if (debug_stoppable) 936 debug_active = 0; 937 } 938 EXPORT_SYMBOL(debug_stop_all); 939 940 void debug_set_critical(void) 941 { 942 debug_critical = 1; 943 } 944 945 /* 946 * debug_event_common: 947 * - write debug entry with given size 948 */ 949 950 debug_entry_t* 951 debug_event_common(debug_info_t * id, int level, const void *buf, int len) 952 { 953 unsigned long flags; 954 debug_entry_t *active; 955 956 if (!debug_active || !id->areas) 957 return NULL; 958 if (debug_critical) { 959 if (!spin_trylock_irqsave(&id->lock, flags)) 960 return NULL; 961 } else 962 spin_lock_irqsave(&id->lock, flags); 963 active = get_active_entry(id); 964 memset(DEBUG_DATA(active), 0, id->buf_size); 965 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 966 debug_finish_entry(id, active, level, 0); 967 spin_unlock_irqrestore(&id->lock, flags); 968 969 return active; 970 } 971 EXPORT_SYMBOL(debug_event_common); 972 973 /* 974 * debug_exception_common: 975 * - write debug entry with given size and switch to next debug area 976 */ 977 978 debug_entry_t 979 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len) 980 { 981 unsigned long flags; 982 debug_entry_t *active; 983 984 if (!debug_active || !id->areas) 985 return NULL; 986 if (debug_critical) { 987 if (!spin_trylock_irqsave(&id->lock, flags)) 988 return NULL; 989 } else 990 spin_lock_irqsave(&id->lock, flags); 991 active = get_active_entry(id); 992 memset(DEBUG_DATA(active), 0, id->buf_size); 993 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 994 debug_finish_entry(id, active, level, 1); 995 spin_unlock_irqrestore(&id->lock, flags); 996 997 return active; 998 } 999 EXPORT_SYMBOL(debug_exception_common); 1000 1001 /* 1002 * counts arguments in format string for sprintf view 1003 */ 1004 1005 static inline int 1006 debug_count_numargs(char *string) 1007 { 1008 int numargs=0; 1009 1010 while(*string) { 1011 if(*string++=='%') 1012 numargs++; 1013 } 1014 return(numargs); 1015 } 1016 1017 /* 1018 * debug_sprintf_event: 1019 */ 1020 1021 debug_entry_t* 1022 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 1023 { 1024 va_list ap; 1025 int numargs,idx; 1026 unsigned long flags; 1027 debug_sprintf_entry_t *curr_event; 1028 debug_entry_t *active; 1029 1030 if (!debug_active || !id->areas) 1031 return NULL; 1032 numargs=debug_count_numargs(string); 1033 1034 if (debug_critical) { 1035 if (!spin_trylock_irqsave(&id->lock, flags)) 1036 return NULL; 1037 } else 1038 spin_lock_irqsave(&id->lock, flags); 1039 active = get_active_entry(id); 1040 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active); 1041 va_start(ap,string); 1042 curr_event->string=string; 1043 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1044 curr_event->args[idx]=va_arg(ap,long); 1045 va_end(ap); 1046 debug_finish_entry(id, active, level, 0); 1047 spin_unlock_irqrestore(&id->lock, flags); 1048 1049 return active; 1050 } 1051 EXPORT_SYMBOL(__debug_sprintf_event); 1052 1053 /* 1054 * debug_sprintf_exception: 1055 */ 1056 1057 debug_entry_t* 1058 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 1059 { 1060 va_list ap; 1061 int numargs,idx; 1062 unsigned long flags; 1063 debug_sprintf_entry_t *curr_event; 1064 debug_entry_t *active; 1065 1066 if (!debug_active || !id->areas) 1067 return NULL; 1068 1069 numargs=debug_count_numargs(string); 1070 1071 if (debug_critical) { 1072 if (!spin_trylock_irqsave(&id->lock, flags)) 1073 return NULL; 1074 } else 1075 spin_lock_irqsave(&id->lock, flags); 1076 active = get_active_entry(id); 1077 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active); 1078 va_start(ap,string); 1079 curr_event->string=string; 1080 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1081 curr_event->args[idx]=va_arg(ap,long); 1082 va_end(ap); 1083 debug_finish_entry(id, active, level, 1); 1084 spin_unlock_irqrestore(&id->lock, flags); 1085 1086 return active; 1087 } 1088 EXPORT_SYMBOL(__debug_sprintf_exception); 1089 1090 /* 1091 * debug_register_view: 1092 */ 1093 1094 int 1095 debug_register_view(debug_info_t * id, struct debug_view *view) 1096 { 1097 int rc = 0; 1098 int i; 1099 unsigned long flags; 1100 umode_t mode; 1101 struct dentry *pde; 1102 1103 if (!id) 1104 goto out; 1105 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1106 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1107 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1108 if (!view->input_proc) 1109 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1110 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1111 id , &debug_file_ops); 1112 if (!pde){ 1113 pr_err("Registering view %s/%s failed due to out of " 1114 "memory\n", id->name,view->name); 1115 rc = -1; 1116 goto out; 1117 } 1118 spin_lock_irqsave(&id->lock, flags); 1119 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1120 if (!id->views[i]) 1121 break; 1122 } 1123 if (i == DEBUG_MAX_VIEWS) { 1124 pr_err("Registering view %s/%s would exceed the maximum " 1125 "number of views %i\n", id->name, view->name, i); 1126 rc = -1; 1127 } else { 1128 id->views[i] = view; 1129 id->debugfs_entries[i] = pde; 1130 } 1131 spin_unlock_irqrestore(&id->lock, flags); 1132 if (rc) 1133 debugfs_remove(pde); 1134 out: 1135 return rc; 1136 } 1137 EXPORT_SYMBOL(debug_register_view); 1138 1139 /* 1140 * debug_unregister_view: 1141 */ 1142 1143 int 1144 debug_unregister_view(debug_info_t * id, struct debug_view *view) 1145 { 1146 struct dentry *dentry = NULL; 1147 unsigned long flags; 1148 int i, rc = 0; 1149 1150 if (!id) 1151 goto out; 1152 spin_lock_irqsave(&id->lock, flags); 1153 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1154 if (id->views[i] == view) 1155 break; 1156 } 1157 if (i == DEBUG_MAX_VIEWS) 1158 rc = -1; 1159 else { 1160 dentry = id->debugfs_entries[i]; 1161 id->views[i] = NULL; 1162 id->debugfs_entries[i] = NULL; 1163 } 1164 spin_unlock_irqrestore(&id->lock, flags); 1165 debugfs_remove(dentry); 1166 out: 1167 return rc; 1168 } 1169 EXPORT_SYMBOL(debug_unregister_view); 1170 1171 static inline char * 1172 debug_get_user_string(const char __user *user_buf, size_t user_len) 1173 { 1174 char* buffer; 1175 1176 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1177 if (!buffer) 1178 return ERR_PTR(-ENOMEM); 1179 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1180 kfree(buffer); 1181 return ERR_PTR(-EFAULT); 1182 } 1183 /* got the string, now strip linefeed. */ 1184 if (buffer[user_len - 1] == '\n') 1185 buffer[user_len - 1] = 0; 1186 else 1187 buffer[user_len] = 0; 1188 return buffer; 1189 } 1190 1191 static inline int 1192 debug_get_uint(char *buf) 1193 { 1194 int rc; 1195 1196 buf = skip_spaces(buf); 1197 rc = simple_strtoul(buf, &buf, 10); 1198 if(*buf){ 1199 rc = -EINVAL; 1200 } 1201 return rc; 1202 } 1203 1204 /* 1205 * functions for debug-views 1206 *********************************** 1207 */ 1208 1209 /* 1210 * prints out actual debug level 1211 */ 1212 1213 static int 1214 debug_prolog_pages_fn(debug_info_t * id, 1215 struct debug_view *view, char *out_buf) 1216 { 1217 return sprintf(out_buf, "%i\n", id->pages_per_area); 1218 } 1219 1220 /* 1221 * reads new size (number of pages per debug area) 1222 */ 1223 1224 static int 1225 debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 1226 struct file *file, const char __user *user_buf, 1227 size_t user_len, loff_t * offset) 1228 { 1229 char *str; 1230 int rc,new_pages; 1231 1232 if (user_len > 0x10000) 1233 user_len = 0x10000; 1234 if (*offset != 0){ 1235 rc = -EPIPE; 1236 goto out; 1237 } 1238 str = debug_get_user_string(user_buf,user_len); 1239 if(IS_ERR(str)){ 1240 rc = PTR_ERR(str); 1241 goto out; 1242 } 1243 new_pages = debug_get_uint(str); 1244 if(new_pages < 0){ 1245 rc = -EINVAL; 1246 goto free_str; 1247 } 1248 rc = debug_set_size(id,id->nr_areas, new_pages); 1249 if(rc != 0){ 1250 rc = -EINVAL; 1251 goto free_str; 1252 } 1253 rc = user_len; 1254 free_str: 1255 kfree(str); 1256 out: 1257 *offset += user_len; 1258 return rc; /* number of input characters */ 1259 } 1260 1261 /* 1262 * prints out actual debug level 1263 */ 1264 1265 static int 1266 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf) 1267 { 1268 int rc = 0; 1269 1270 if(id->level == DEBUG_OFF_LEVEL) { 1271 rc = sprintf(out_buf,"-\n"); 1272 } 1273 else { 1274 rc = sprintf(out_buf, "%i\n", id->level); 1275 } 1276 return rc; 1277 } 1278 1279 /* 1280 * reads new debug level 1281 */ 1282 1283 static int 1284 debug_input_level_fn(debug_info_t * id, struct debug_view *view, 1285 struct file *file, const char __user *user_buf, 1286 size_t user_len, loff_t * offset) 1287 { 1288 char *str; 1289 int rc,new_level; 1290 1291 if (user_len > 0x10000) 1292 user_len = 0x10000; 1293 if (*offset != 0){ 1294 rc = -EPIPE; 1295 goto out; 1296 } 1297 str = debug_get_user_string(user_buf,user_len); 1298 if(IS_ERR(str)){ 1299 rc = PTR_ERR(str); 1300 goto out; 1301 } 1302 if(str[0] == '-'){ 1303 debug_set_level(id, DEBUG_OFF_LEVEL); 1304 rc = user_len; 1305 goto free_str; 1306 } else { 1307 new_level = debug_get_uint(str); 1308 } 1309 if(new_level < 0) { 1310 pr_warn("%s is not a valid level for a debug feature\n", str); 1311 rc = -EINVAL; 1312 } else { 1313 debug_set_level(id, new_level); 1314 rc = user_len; 1315 } 1316 free_str: 1317 kfree(str); 1318 out: 1319 *offset += user_len; 1320 return rc; /* number of input characters */ 1321 } 1322 1323 1324 /* 1325 * flushes debug areas 1326 */ 1327 1328 static void debug_flush(debug_info_t* id, int area) 1329 { 1330 unsigned long flags; 1331 int i,j; 1332 1333 if(!id || !id->areas) 1334 return; 1335 spin_lock_irqsave(&id->lock,flags); 1336 if(area == DEBUG_FLUSH_ALL){ 1337 id->active_area = 0; 1338 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1339 for (i = 0; i < id->nr_areas; i++) { 1340 id->active_pages[i] = 0; 1341 for(j = 0; j < id->pages_per_area; j++) { 1342 memset(id->areas[i][j], 0, PAGE_SIZE); 1343 } 1344 } 1345 } else if(area >= 0 && area < id->nr_areas) { 1346 id->active_entries[area] = 0; 1347 id->active_pages[area] = 0; 1348 for(i = 0; i < id->pages_per_area; i++) { 1349 memset(id->areas[area][i],0,PAGE_SIZE); 1350 } 1351 } 1352 spin_unlock_irqrestore(&id->lock,flags); 1353 } 1354 1355 /* 1356 * view function: flushes debug areas 1357 */ 1358 1359 static int 1360 debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 1361 struct file *file, const char __user *user_buf, 1362 size_t user_len, loff_t * offset) 1363 { 1364 char input_buf[1]; 1365 int rc = user_len; 1366 1367 if (user_len > 0x10000) 1368 user_len = 0x10000; 1369 if (*offset != 0){ 1370 rc = -EPIPE; 1371 goto out; 1372 } 1373 if (copy_from_user(input_buf, user_buf, 1)){ 1374 rc = -EFAULT; 1375 goto out; 1376 } 1377 if(input_buf[0] == '-') { 1378 debug_flush(id, DEBUG_FLUSH_ALL); 1379 goto out; 1380 } 1381 if (isdigit(input_buf[0])) { 1382 int area = ((int) input_buf[0] - (int) '0'); 1383 debug_flush(id, area); 1384 goto out; 1385 } 1386 1387 pr_info("Flushing debug data failed because %c is not a valid " 1388 "area\n", input_buf[0]); 1389 1390 out: 1391 *offset += user_len; 1392 return rc; /* number of input characters */ 1393 } 1394 1395 /* 1396 * prints debug header in raw format 1397 */ 1398 1399 static int 1400 debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 1401 int area, debug_entry_t * entry, char *out_buf) 1402 { 1403 int rc; 1404 1405 rc = sizeof(debug_entry_t); 1406 memcpy(out_buf,entry,sizeof(debug_entry_t)); 1407 return rc; 1408 } 1409 1410 /* 1411 * prints debug data in raw format 1412 */ 1413 1414 static int 1415 debug_raw_format_fn(debug_info_t * id, struct debug_view *view, 1416 char *out_buf, const char *in_buf) 1417 { 1418 int rc; 1419 1420 rc = id->buf_size; 1421 memcpy(out_buf, in_buf, id->buf_size); 1422 return rc; 1423 } 1424 1425 /* 1426 * prints debug data in hex/ascii format 1427 */ 1428 1429 static int 1430 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 1431 char *out_buf, const char *in_buf) 1432 { 1433 int i, rc = 0; 1434 1435 for (i = 0; i < id->buf_size; i++) { 1436 rc += sprintf(out_buf + rc, "%02x ", 1437 ((unsigned char *) in_buf)[i]); 1438 } 1439 rc += sprintf(out_buf + rc, "| "); 1440 for (i = 0; i < id->buf_size; i++) { 1441 unsigned char c = in_buf[i]; 1442 if (isascii(c) && isprint(c)) 1443 rc += sprintf(out_buf + rc, "%c", c); 1444 else 1445 rc += sprintf(out_buf + rc, "."); 1446 } 1447 rc += sprintf(out_buf + rc, "\n"); 1448 return rc; 1449 } 1450 1451 /* 1452 * prints header for debug entry 1453 */ 1454 1455 int 1456 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view, 1457 int area, debug_entry_t * entry, char *out_buf) 1458 { 1459 unsigned long base, sec, usec; 1460 char *except_str; 1461 unsigned long caller; 1462 int rc = 0; 1463 unsigned int level; 1464 1465 level = entry->id.fields.level; 1466 base = (*(unsigned long *) &tod_clock_base[0]) >> 4; 1467 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12); 1468 usec = do_div(sec, USEC_PER_SEC); 1469 1470 if (entry->id.fields.exception) 1471 except_str = "*"; 1472 else 1473 except_str = "-"; 1474 caller = (unsigned long) entry->caller; 1475 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %p ", 1476 area, sec, usec, level, except_str, 1477 entry->id.fields.cpuid, (void *)caller); 1478 return rc; 1479 } 1480 EXPORT_SYMBOL(debug_dflt_header_fn); 1481 1482 /* 1483 * prints debug data sprintf-formated: 1484 * debug_sprinf_event/exception calls must be used together with this view 1485 */ 1486 1487 #define DEBUG_SPRINTF_MAX_ARGS 10 1488 1489 static int 1490 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 1491 char *out_buf, debug_sprintf_entry_t *curr_event) 1492 { 1493 int num_longs, num_used_args = 0,i, rc = 0; 1494 int index[DEBUG_SPRINTF_MAX_ARGS]; 1495 1496 /* count of longs fit into one entry */ 1497 num_longs = id->buf_size / sizeof(long); 1498 1499 if(num_longs < 1) 1500 goto out; /* bufsize of entry too small */ 1501 if(num_longs == 1) { 1502 /* no args, we use only the string */ 1503 strcpy(out_buf, curr_event->string); 1504 rc = strlen(curr_event->string); 1505 goto out; 1506 } 1507 1508 /* number of arguments used for sprintf (without the format string) */ 1509 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1510 1511 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1512 1513 for(i = 0; i < num_used_args; i++) 1514 index[i] = i; 1515 1516 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1517 curr_event->args[index[1]], curr_event->args[index[2]], 1518 curr_event->args[index[3]], curr_event->args[index[4]], 1519 curr_event->args[index[5]], curr_event->args[index[6]], 1520 curr_event->args[index[7]], curr_event->args[index[8]], 1521 curr_event->args[index[9]]); 1522 1523 out: 1524 1525 return rc; 1526 } 1527 1528 /* 1529 * debug_init: 1530 * - is called exactly once to initialize the debug feature 1531 */ 1532 static int __init debug_init(void) 1533 { 1534 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1535 mutex_lock(&debug_mutex); 1536 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1537 initialized = 1; 1538 mutex_unlock(&debug_mutex); 1539 return 0; 1540 } 1541 postcore_initcall(debug_init); 1542