1 /* 2 * S/390 debug facility 3 * 4 * Copyright IBM Corp. 1999, 2012 5 * 6 * Author(s): Michael Holzheu (holzheu@de.ibm.com), 7 * Holger Smolinski (Holger.Smolinski@de.ibm.com) 8 * 9 * Bugreports to: <Linux390@de.ibm.com> 10 */ 11 12 #define KMSG_COMPONENT "s390dbf" 13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 14 15 #include <linux/stddef.h> 16 #include <linux/kernel.h> 17 #include <linux/errno.h> 18 #include <linux/slab.h> 19 #include <linux/ctype.h> 20 #include <linux/string.h> 21 #include <linux/sysctl.h> 22 #include <asm/uaccess.h> 23 #include <linux/module.h> 24 #include <linux/init.h> 25 #include <linux/fs.h> 26 #include <linux/debugfs.h> 27 28 #include <asm/debug.h> 29 30 #define DEBUG_PROLOG_ENTRY -1 31 32 #define ALL_AREAS 0 /* copy all debug areas */ 33 #define NO_AREAS 1 /* copy no debug areas */ 34 35 /* typedefs */ 36 37 typedef struct file_private_info { 38 loff_t offset; /* offset of last read in file */ 39 int act_area; /* number of last formated area */ 40 int act_page; /* act page in given area */ 41 int act_entry; /* last formated entry (offset */ 42 /* relative to beginning of last */ 43 /* formated page) */ 44 size_t act_entry_offset; /* up to this offset we copied */ 45 /* in last read the last formated */ 46 /* entry to userland */ 47 char temp_buf[2048]; /* buffer for output */ 48 debug_info_t *debug_info_org; /* original debug information */ 49 debug_info_t *debug_info_snap; /* snapshot of debug information */ 50 struct debug_view *view; /* used view of debug info */ 51 } file_private_info_t; 52 53 typedef struct 54 { 55 char *string; 56 /* 57 * This assumes that all args are converted into longs 58 * on L/390 this is the case for all types of parameter 59 * except of floats, and long long (32 bit) 60 * 61 */ 62 long args[0]; 63 } debug_sprintf_entry_t; 64 65 66 /* internal function prototyes */ 67 68 static int debug_init(void); 69 static ssize_t debug_output(struct file *file, char __user *user_buf, 70 size_t user_len, loff_t * offset); 71 static ssize_t debug_input(struct file *file, const char __user *user_buf, 72 size_t user_len, loff_t * offset); 73 static int debug_open(struct inode *inode, struct file *file); 74 static int debug_close(struct inode *inode, struct file *file); 75 static debug_info_t *debug_info_create(const char *name, int pages_per_area, 76 int nr_areas, int buf_size, umode_t mode); 77 static void debug_info_get(debug_info_t *); 78 static void debug_info_put(debug_info_t *); 79 static int debug_prolog_level_fn(debug_info_t * id, 80 struct debug_view *view, char *out_buf); 81 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view, 82 struct file *file, const char __user *user_buf, 83 size_t user_buf_size, loff_t * offset); 84 static int debug_prolog_pages_fn(debug_info_t * id, 85 struct debug_view *view, char *out_buf); 86 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 87 struct file *file, const char __user *user_buf, 88 size_t user_buf_size, loff_t * offset); 89 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 90 struct file *file, const char __user *user_buf, 91 size_t user_buf_size, loff_t * offset); 92 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 93 char *out_buf, const char *in_buf); 94 static int debug_raw_format_fn(debug_info_t * id, 95 struct debug_view *view, char *out_buf, 96 const char *in_buf); 97 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 98 int area, debug_entry_t * entry, char *out_buf); 99 100 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 101 char *out_buf, debug_sprintf_entry_t *curr_event); 102 103 /* globals */ 104 105 struct debug_view debug_raw_view = { 106 "raw", 107 NULL, 108 &debug_raw_header_fn, 109 &debug_raw_format_fn, 110 NULL, 111 NULL 112 }; 113 114 struct debug_view debug_hex_ascii_view = { 115 "hex_ascii", 116 NULL, 117 &debug_dflt_header_fn, 118 &debug_hex_ascii_format_fn, 119 NULL, 120 NULL 121 }; 122 123 static struct debug_view debug_level_view = { 124 "level", 125 &debug_prolog_level_fn, 126 NULL, 127 NULL, 128 &debug_input_level_fn, 129 NULL 130 }; 131 132 static struct debug_view debug_pages_view = { 133 "pages", 134 &debug_prolog_pages_fn, 135 NULL, 136 NULL, 137 &debug_input_pages_fn, 138 NULL 139 }; 140 141 static struct debug_view debug_flush_view = { 142 "flush", 143 NULL, 144 NULL, 145 NULL, 146 &debug_input_flush_fn, 147 NULL 148 }; 149 150 struct debug_view debug_sprintf_view = { 151 "sprintf", 152 NULL, 153 &debug_dflt_header_fn, 154 (debug_format_proc_t*)&debug_sprintf_format_fn, 155 NULL, 156 NULL 157 }; 158 159 /* used by dump analysis tools to determine version of debug feature */ 160 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 161 162 /* static globals */ 163 164 static debug_info_t *debug_area_first = NULL; 165 static debug_info_t *debug_area_last = NULL; 166 static DEFINE_MUTEX(debug_mutex); 167 168 static int initialized; 169 static int debug_critical; 170 171 static const struct file_operations debug_file_ops = { 172 .owner = THIS_MODULE, 173 .read = debug_output, 174 .write = debug_input, 175 .open = debug_open, 176 .release = debug_close, 177 .llseek = no_llseek, 178 }; 179 180 static struct dentry *debug_debugfs_root_entry; 181 182 /* functions */ 183 184 /* 185 * debug_areas_alloc 186 * - Debug areas are implemented as a threedimensonal array: 187 * areas[areanumber][pagenumber][pageoffset] 188 */ 189 190 static debug_entry_t*** 191 debug_areas_alloc(int pages_per_area, int nr_areas) 192 { 193 debug_entry_t*** areas; 194 int i,j; 195 196 areas = kmalloc(nr_areas * 197 sizeof(debug_entry_t**), 198 GFP_KERNEL); 199 if (!areas) 200 goto fail_malloc_areas; 201 for (i = 0; i < nr_areas; i++) { 202 areas[i] = kmalloc(pages_per_area * 203 sizeof(debug_entry_t*),GFP_KERNEL); 204 if (!areas[i]) { 205 goto fail_malloc_areas2; 206 } 207 for(j = 0; j < pages_per_area; j++) { 208 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); 209 if(!areas[i][j]) { 210 for(j--; j >=0 ; j--) { 211 kfree(areas[i][j]); 212 } 213 kfree(areas[i]); 214 goto fail_malloc_areas2; 215 } 216 } 217 } 218 return areas; 219 220 fail_malloc_areas2: 221 for(i--; i >= 0; i--){ 222 for(j=0; j < pages_per_area;j++){ 223 kfree(areas[i][j]); 224 } 225 kfree(areas[i]); 226 } 227 kfree(areas); 228 fail_malloc_areas: 229 return NULL; 230 231 } 232 233 234 /* 235 * debug_info_alloc 236 * - alloc new debug-info 237 */ 238 239 static debug_info_t* 240 debug_info_alloc(const char *name, int pages_per_area, int nr_areas, 241 int buf_size, int level, int mode) 242 { 243 debug_info_t* rc; 244 245 /* alloc everything */ 246 247 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); 248 if(!rc) 249 goto fail_malloc_rc; 250 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 251 if(!rc->active_entries) 252 goto fail_malloc_active_entries; 253 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 254 if(!rc->active_pages) 255 goto fail_malloc_active_pages; 256 if((mode == ALL_AREAS) && (pages_per_area != 0)){ 257 rc->areas = debug_areas_alloc(pages_per_area, nr_areas); 258 if(!rc->areas) 259 goto fail_malloc_areas; 260 } else { 261 rc->areas = NULL; 262 } 263 264 /* initialize members */ 265 266 spin_lock_init(&rc->lock); 267 rc->pages_per_area = pages_per_area; 268 rc->nr_areas = nr_areas; 269 rc->active_area = 0; 270 rc->level = level; 271 rc->buf_size = buf_size; 272 rc->entry_size = sizeof(debug_entry_t) + buf_size; 273 strlcpy(rc->name, name, sizeof(rc->name)); 274 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); 275 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS * 276 sizeof(struct dentry*)); 277 atomic_set(&(rc->ref_count), 0); 278 279 return rc; 280 281 fail_malloc_areas: 282 kfree(rc->active_pages); 283 fail_malloc_active_pages: 284 kfree(rc->active_entries); 285 fail_malloc_active_entries: 286 kfree(rc); 287 fail_malloc_rc: 288 return NULL; 289 } 290 291 /* 292 * debug_areas_free 293 * - free all debug areas 294 */ 295 296 static void 297 debug_areas_free(debug_info_t* db_info) 298 { 299 int i,j; 300 301 if(!db_info->areas) 302 return; 303 for (i = 0; i < db_info->nr_areas; i++) { 304 for(j = 0; j < db_info->pages_per_area; j++) { 305 kfree(db_info->areas[i][j]); 306 } 307 kfree(db_info->areas[i]); 308 } 309 kfree(db_info->areas); 310 db_info->areas = NULL; 311 } 312 313 /* 314 * debug_info_free 315 * - free memory debug-info 316 */ 317 318 static void 319 debug_info_free(debug_info_t* db_info){ 320 debug_areas_free(db_info); 321 kfree(db_info->active_entries); 322 kfree(db_info->active_pages); 323 kfree(db_info); 324 } 325 326 /* 327 * debug_info_create 328 * - create new debug-info 329 */ 330 331 static debug_info_t* 332 debug_info_create(const char *name, int pages_per_area, int nr_areas, 333 int buf_size, umode_t mode) 334 { 335 debug_info_t* rc; 336 337 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, 338 DEBUG_DEFAULT_LEVEL, ALL_AREAS); 339 if(!rc) 340 goto out; 341 342 rc->mode = mode & ~S_IFMT; 343 344 /* create root directory */ 345 rc->debugfs_root_entry = debugfs_create_dir(rc->name, 346 debug_debugfs_root_entry); 347 348 /* append new element to linked list */ 349 if (!debug_area_first) { 350 /* first element in list */ 351 debug_area_first = rc; 352 rc->prev = NULL; 353 } else { 354 /* append element to end of list */ 355 debug_area_last->next = rc; 356 rc->prev = debug_area_last; 357 } 358 debug_area_last = rc; 359 rc->next = NULL; 360 361 debug_info_get(rc); 362 out: 363 return rc; 364 } 365 366 /* 367 * debug_info_copy 368 * - copy debug-info 369 */ 370 371 static debug_info_t* 372 debug_info_copy(debug_info_t* in, int mode) 373 { 374 int i,j; 375 debug_info_t* rc; 376 unsigned long flags; 377 378 /* get a consistent copy of the debug areas */ 379 do { 380 rc = debug_info_alloc(in->name, in->pages_per_area, 381 in->nr_areas, in->buf_size, in->level, mode); 382 spin_lock_irqsave(&in->lock, flags); 383 if(!rc) 384 goto out; 385 /* has something changed in the meantime ? */ 386 if((rc->pages_per_area == in->pages_per_area) && 387 (rc->nr_areas == in->nr_areas)) { 388 break; 389 } 390 spin_unlock_irqrestore(&in->lock, flags); 391 debug_info_free(rc); 392 } while (1); 393 394 if (mode == NO_AREAS) 395 goto out; 396 397 for(i = 0; i < in->nr_areas; i++){ 398 for(j = 0; j < in->pages_per_area; j++) { 399 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE); 400 } 401 } 402 out: 403 spin_unlock_irqrestore(&in->lock, flags); 404 return rc; 405 } 406 407 /* 408 * debug_info_get 409 * - increments reference count for debug-info 410 */ 411 412 static void 413 debug_info_get(debug_info_t * db_info) 414 { 415 if (db_info) 416 atomic_inc(&db_info->ref_count); 417 } 418 419 /* 420 * debug_info_put: 421 * - decreases reference count for debug-info and frees it if necessary 422 */ 423 424 static void 425 debug_info_put(debug_info_t *db_info) 426 { 427 int i; 428 429 if (!db_info) 430 return; 431 if (atomic_dec_and_test(&db_info->ref_count)) { 432 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 433 if (!db_info->views[i]) 434 continue; 435 debugfs_remove(db_info->debugfs_entries[i]); 436 } 437 debugfs_remove(db_info->debugfs_root_entry); 438 if(db_info == debug_area_first) 439 debug_area_first = db_info->next; 440 if(db_info == debug_area_last) 441 debug_area_last = db_info->prev; 442 if(db_info->prev) db_info->prev->next = db_info->next; 443 if(db_info->next) db_info->next->prev = db_info->prev; 444 debug_info_free(db_info); 445 } 446 } 447 448 /* 449 * debug_format_entry: 450 * - format one debug entry and return size of formated data 451 */ 452 453 static int 454 debug_format_entry(file_private_info_t *p_info) 455 { 456 debug_info_t *id_snap = p_info->debug_info_snap; 457 struct debug_view *view = p_info->view; 458 debug_entry_t *act_entry; 459 size_t len = 0; 460 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 461 /* print prolog */ 462 if (view->prolog_proc) 463 len += view->prolog_proc(id_snap,view,p_info->temp_buf); 464 goto out; 465 } 466 if (!id_snap->areas) /* this is true, if we have a prolog only view */ 467 goto out; /* or if 'pages_per_area' is 0 */ 468 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area] 469 [p_info->act_page] + p_info->act_entry); 470 471 if (act_entry->id.stck == 0LL) 472 goto out; /* empty entry */ 473 if (view->header_proc) 474 len += view->header_proc(id_snap, view, p_info->act_area, 475 act_entry, p_info->temp_buf + len); 476 if (view->format_proc) 477 len += view->format_proc(id_snap, view, p_info->temp_buf + len, 478 DEBUG_DATA(act_entry)); 479 out: 480 return len; 481 } 482 483 /* 484 * debug_next_entry: 485 * - goto next entry in p_info 486 */ 487 488 static inline int 489 debug_next_entry(file_private_info_t *p_info) 490 { 491 debug_info_t *id; 492 493 id = p_info->debug_info_snap; 494 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 495 p_info->act_entry = 0; 496 p_info->act_page = 0; 497 goto out; 498 } 499 if(!id->areas) 500 return 1; 501 p_info->act_entry += id->entry_size; 502 /* switch to next page, if we reached the end of the page */ 503 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){ 504 /* next page */ 505 p_info->act_entry = 0; 506 p_info->act_page += 1; 507 if((p_info->act_page % id->pages_per_area) == 0) { 508 /* next area */ 509 p_info->act_area++; 510 p_info->act_page=0; 511 } 512 if(p_info->act_area >= id->nr_areas) 513 return 1; 514 } 515 out: 516 return 0; 517 } 518 519 /* 520 * debug_output: 521 * - called for user read() 522 * - copies formated debug entries to the user buffer 523 */ 524 525 static ssize_t 526 debug_output(struct file *file, /* file descriptor */ 527 char __user *user_buf, /* user buffer */ 528 size_t len, /* length of buffer */ 529 loff_t *offset) /* offset in the file */ 530 { 531 size_t count = 0; 532 size_t entry_offset; 533 file_private_info_t *p_info; 534 535 p_info = ((file_private_info_t *) file->private_data); 536 if (*offset != p_info->offset) 537 return -EPIPE; 538 if(p_info->act_area >= p_info->debug_info_snap->nr_areas) 539 return 0; 540 entry_offset = p_info->act_entry_offset; 541 while(count < len){ 542 int formatted_line_size; 543 int formatted_line_residue; 544 int user_buf_residue; 545 size_t copy_size; 546 547 formatted_line_size = debug_format_entry(p_info); 548 formatted_line_residue = formatted_line_size - entry_offset; 549 user_buf_residue = len-count; 550 copy_size = min(user_buf_residue, formatted_line_residue); 551 if(copy_size){ 552 if (copy_to_user(user_buf + count, p_info->temp_buf 553 + entry_offset, copy_size)) 554 return -EFAULT; 555 count += copy_size; 556 entry_offset += copy_size; 557 } 558 if(copy_size == formatted_line_residue){ 559 entry_offset = 0; 560 if(debug_next_entry(p_info)) 561 goto out; 562 } 563 } 564 out: 565 p_info->offset = *offset + count; 566 p_info->act_entry_offset = entry_offset; 567 *offset = p_info->offset; 568 return count; 569 } 570 571 /* 572 * debug_input: 573 * - called for user write() 574 * - calls input function of view 575 */ 576 577 static ssize_t 578 debug_input(struct file *file, const char __user *user_buf, size_t length, 579 loff_t *offset) 580 { 581 int rc = 0; 582 file_private_info_t *p_info; 583 584 mutex_lock(&debug_mutex); 585 p_info = ((file_private_info_t *) file->private_data); 586 if (p_info->view->input_proc) 587 rc = p_info->view->input_proc(p_info->debug_info_org, 588 p_info->view, file, user_buf, 589 length, offset); 590 else 591 rc = -EPERM; 592 mutex_unlock(&debug_mutex); 593 return rc; /* number of input characters */ 594 } 595 596 /* 597 * debug_open: 598 * - called for user open() 599 * - copies formated output to private_data area of the file 600 * handle 601 */ 602 603 static int 604 debug_open(struct inode *inode, struct file *file) 605 { 606 int i, rc = 0; 607 file_private_info_t *p_info; 608 debug_info_t *debug_info, *debug_info_snapshot; 609 610 mutex_lock(&debug_mutex); 611 debug_info = file->f_path.dentry->d_inode->i_private; 612 /* find debug view */ 613 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 614 if (!debug_info->views[i]) 615 continue; 616 else if (debug_info->debugfs_entries[i] == 617 file->f_path.dentry) { 618 goto found; /* found view ! */ 619 } 620 } 621 /* no entry found */ 622 rc = -EINVAL; 623 goto out; 624 625 found: 626 627 /* Make snapshot of current debug areas to get it consistent. */ 628 /* To copy all the areas is only needed, if we have a view which */ 629 /* formats the debug areas. */ 630 631 if(!debug_info->views[i]->format_proc && 632 !debug_info->views[i]->header_proc){ 633 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS); 634 } else { 635 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS); 636 } 637 638 if(!debug_info_snapshot){ 639 rc = -ENOMEM; 640 goto out; 641 } 642 p_info = kmalloc(sizeof(file_private_info_t), 643 GFP_KERNEL); 644 if(!p_info){ 645 debug_info_free(debug_info_snapshot); 646 rc = -ENOMEM; 647 goto out; 648 } 649 p_info->offset = 0; 650 p_info->debug_info_snap = debug_info_snapshot; 651 p_info->debug_info_org = debug_info; 652 p_info->view = debug_info->views[i]; 653 p_info->act_area = 0; 654 p_info->act_page = 0; 655 p_info->act_entry = DEBUG_PROLOG_ENTRY; 656 p_info->act_entry_offset = 0; 657 file->private_data = p_info; 658 debug_info_get(debug_info); 659 nonseekable_open(inode, file); 660 out: 661 mutex_unlock(&debug_mutex); 662 return rc; 663 } 664 665 /* 666 * debug_close: 667 * - called for user close() 668 * - deletes private_data area of the file handle 669 */ 670 671 static int 672 debug_close(struct inode *inode, struct file *file) 673 { 674 file_private_info_t *p_info; 675 p_info = (file_private_info_t *) file->private_data; 676 if(p_info->debug_info_snap) 677 debug_info_free(p_info->debug_info_snap); 678 debug_info_put(p_info->debug_info_org); 679 kfree(file->private_data); 680 return 0; /* success */ 681 } 682 683 /* 684 * debug_register_mode: 685 * - Creates and initializes debug area for the caller 686 * The mode parameter allows to specify access rights for the s390dbf files 687 * - Returns handle for debug area 688 */ 689 690 debug_info_t *debug_register_mode(const char *name, int pages_per_area, 691 int nr_areas, int buf_size, umode_t mode, 692 uid_t uid, gid_t gid) 693 { 694 debug_info_t *rc = NULL; 695 696 /* Since debugfs currently does not support uid/gid other than root, */ 697 /* we do not allow gid/uid != 0 until we get support for that. */ 698 if ((uid != 0) || (gid != 0)) 699 pr_warning("Root becomes the owner of all s390dbf files " 700 "in sysfs\n"); 701 BUG_ON(!initialized); 702 mutex_lock(&debug_mutex); 703 704 /* create new debug_info */ 705 706 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 707 if(!rc) 708 goto out; 709 debug_register_view(rc, &debug_level_view); 710 debug_register_view(rc, &debug_flush_view); 711 debug_register_view(rc, &debug_pages_view); 712 out: 713 if (!rc){ 714 pr_err("Registering debug feature %s failed\n", name); 715 } 716 mutex_unlock(&debug_mutex); 717 return rc; 718 } 719 EXPORT_SYMBOL(debug_register_mode); 720 721 /* 722 * debug_register: 723 * - creates and initializes debug area for the caller 724 * - returns handle for debug area 725 */ 726 727 debug_info_t *debug_register(const char *name, int pages_per_area, 728 int nr_areas, int buf_size) 729 { 730 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 731 S_IRUSR | S_IWUSR, 0, 0); 732 } 733 734 /* 735 * debug_unregister: 736 * - give back debug area 737 */ 738 739 void 740 debug_unregister(debug_info_t * id) 741 { 742 if (!id) 743 goto out; 744 mutex_lock(&debug_mutex); 745 debug_info_put(id); 746 mutex_unlock(&debug_mutex); 747 748 out: 749 return; 750 } 751 752 /* 753 * debug_set_size: 754 * - set area size (number of pages) and number of areas 755 */ 756 static int 757 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area) 758 { 759 unsigned long flags; 760 debug_entry_t *** new_areas; 761 int rc=0; 762 763 if(!id || (nr_areas <= 0) || (pages_per_area < 0)) 764 return -EINVAL; 765 if(pages_per_area > 0){ 766 new_areas = debug_areas_alloc(pages_per_area, nr_areas); 767 if(!new_areas) { 768 pr_info("Allocating memory for %i pages failed\n", 769 pages_per_area); 770 rc = -ENOMEM; 771 goto out; 772 } 773 } else { 774 new_areas = NULL; 775 } 776 spin_lock_irqsave(&id->lock,flags); 777 debug_areas_free(id); 778 id->areas = new_areas; 779 id->nr_areas = nr_areas; 780 id->pages_per_area = pages_per_area; 781 id->active_area = 0; 782 memset(id->active_entries,0,sizeof(int)*id->nr_areas); 783 memset(id->active_pages, 0, sizeof(int)*id->nr_areas); 784 spin_unlock_irqrestore(&id->lock,flags); 785 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area); 786 out: 787 return rc; 788 } 789 790 /* 791 * debug_set_level: 792 * - set actual debug level 793 */ 794 795 void 796 debug_set_level(debug_info_t* id, int new_level) 797 { 798 unsigned long flags; 799 if(!id) 800 return; 801 spin_lock_irqsave(&id->lock,flags); 802 if(new_level == DEBUG_OFF_LEVEL){ 803 id->level = DEBUG_OFF_LEVEL; 804 pr_info("%s: switched off\n",id->name); 805 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 806 pr_info("%s: level %i is out of range (%i - %i)\n", 807 id->name, new_level, 0, DEBUG_MAX_LEVEL); 808 } else { 809 id->level = new_level; 810 } 811 spin_unlock_irqrestore(&id->lock,flags); 812 } 813 814 815 /* 816 * proceed_active_entry: 817 * - set active entry to next in the ring buffer 818 */ 819 820 static inline void 821 proceed_active_entry(debug_info_t * id) 822 { 823 if ((id->active_entries[id->active_area] += id->entry_size) 824 > (PAGE_SIZE - id->entry_size)){ 825 id->active_entries[id->active_area] = 0; 826 id->active_pages[id->active_area] = 827 (id->active_pages[id->active_area] + 1) % 828 id->pages_per_area; 829 } 830 } 831 832 /* 833 * proceed_active_area: 834 * - set active area to next in the ring buffer 835 */ 836 837 static inline void 838 proceed_active_area(debug_info_t * id) 839 { 840 id->active_area++; 841 id->active_area = id->active_area % id->nr_areas; 842 } 843 844 /* 845 * get_active_entry: 846 */ 847 848 static inline debug_entry_t* 849 get_active_entry(debug_info_t * id) 850 { 851 return (debug_entry_t *) (((char *) id->areas[id->active_area] 852 [id->active_pages[id->active_area]]) + 853 id->active_entries[id->active_area]); 854 } 855 856 /* 857 * debug_finish_entry: 858 * - set timestamp, caller address, cpu number etc. 859 */ 860 861 static inline void 862 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level, 863 int exception) 864 { 865 active->id.stck = get_clock(); 866 active->id.fields.cpuid = smp_processor_id(); 867 active->caller = __builtin_return_address(0); 868 active->id.fields.exception = exception; 869 active->id.fields.level = level; 870 proceed_active_entry(id); 871 if(exception) 872 proceed_active_area(id); 873 } 874 875 static int debug_stoppable=1; 876 static int debug_active=1; 877 878 #define CTL_S390DBF_STOPPABLE 5678 879 #define CTL_S390DBF_ACTIVE 5679 880 881 /* 882 * proc handler for the running debug_active sysctl 883 * always allow read, allow write only if debug_stoppable is set or 884 * if debug_active is already off 885 */ 886 static int 887 s390dbf_procactive(ctl_table *table, int write, 888 void __user *buffer, size_t *lenp, loff_t *ppos) 889 { 890 if (!write || debug_stoppable || !debug_active) 891 return proc_dointvec(table, write, buffer, lenp, ppos); 892 else 893 return 0; 894 } 895 896 897 static struct ctl_table s390dbf_table[] = { 898 { 899 .procname = "debug_stoppable", 900 .data = &debug_stoppable, 901 .maxlen = sizeof(int), 902 .mode = S_IRUGO | S_IWUSR, 903 .proc_handler = proc_dointvec, 904 }, 905 { 906 .procname = "debug_active", 907 .data = &debug_active, 908 .maxlen = sizeof(int), 909 .mode = S_IRUGO | S_IWUSR, 910 .proc_handler = s390dbf_procactive, 911 }, 912 { } 913 }; 914 915 static struct ctl_table s390dbf_dir_table[] = { 916 { 917 .procname = "s390dbf", 918 .maxlen = 0, 919 .mode = S_IRUGO | S_IXUGO, 920 .child = s390dbf_table, 921 }, 922 { } 923 }; 924 925 static struct ctl_table_header *s390dbf_sysctl_header; 926 927 void 928 debug_stop_all(void) 929 { 930 if (debug_stoppable) 931 debug_active = 0; 932 } 933 934 935 void debug_set_critical(void) 936 { 937 debug_critical = 1; 938 } 939 940 /* 941 * debug_event_common: 942 * - write debug entry with given size 943 */ 944 945 debug_entry_t* 946 debug_event_common(debug_info_t * id, int level, const void *buf, int len) 947 { 948 unsigned long flags; 949 debug_entry_t *active; 950 951 if (!debug_active || !id->areas) 952 return NULL; 953 if (debug_critical) { 954 if (!spin_trylock_irqsave(&id->lock, flags)) 955 return NULL; 956 } else 957 spin_lock_irqsave(&id->lock, flags); 958 active = get_active_entry(id); 959 memset(DEBUG_DATA(active), 0, id->buf_size); 960 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 961 debug_finish_entry(id, active, level, 0); 962 spin_unlock_irqrestore(&id->lock, flags); 963 964 return active; 965 } 966 967 /* 968 * debug_exception_common: 969 * - write debug entry with given size and switch to next debug area 970 */ 971 972 debug_entry_t 973 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len) 974 { 975 unsigned long flags; 976 debug_entry_t *active; 977 978 if (!debug_active || !id->areas) 979 return NULL; 980 if (debug_critical) { 981 if (!spin_trylock_irqsave(&id->lock, flags)) 982 return NULL; 983 } else 984 spin_lock_irqsave(&id->lock, flags); 985 active = get_active_entry(id); 986 memset(DEBUG_DATA(active), 0, id->buf_size); 987 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 988 debug_finish_entry(id, active, level, 1); 989 spin_unlock_irqrestore(&id->lock, flags); 990 991 return active; 992 } 993 994 /* 995 * counts arguments in format string for sprintf view 996 */ 997 998 static inline int 999 debug_count_numargs(char *string) 1000 { 1001 int numargs=0; 1002 1003 while(*string) { 1004 if(*string++=='%') 1005 numargs++; 1006 } 1007 return(numargs); 1008 } 1009 1010 /* 1011 * debug_sprintf_event: 1012 */ 1013 1014 debug_entry_t* 1015 debug_sprintf_event(debug_info_t* id, int level,char *string,...) 1016 { 1017 va_list ap; 1018 int numargs,idx; 1019 unsigned long flags; 1020 debug_sprintf_entry_t *curr_event; 1021 debug_entry_t *active; 1022 1023 if((!id) || (level > id->level)) 1024 return NULL; 1025 if (!debug_active || !id->areas) 1026 return NULL; 1027 numargs=debug_count_numargs(string); 1028 1029 if (debug_critical) { 1030 if (!spin_trylock_irqsave(&id->lock, flags)) 1031 return NULL; 1032 } else 1033 spin_lock_irqsave(&id->lock, flags); 1034 active = get_active_entry(id); 1035 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active); 1036 va_start(ap,string); 1037 curr_event->string=string; 1038 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1039 curr_event->args[idx]=va_arg(ap,long); 1040 va_end(ap); 1041 debug_finish_entry(id, active, level, 0); 1042 spin_unlock_irqrestore(&id->lock, flags); 1043 1044 return active; 1045 } 1046 1047 /* 1048 * debug_sprintf_exception: 1049 */ 1050 1051 debug_entry_t* 1052 debug_sprintf_exception(debug_info_t* id, int level,char *string,...) 1053 { 1054 va_list ap; 1055 int numargs,idx; 1056 unsigned long flags; 1057 debug_sprintf_entry_t *curr_event; 1058 debug_entry_t *active; 1059 1060 if((!id) || (level > id->level)) 1061 return NULL; 1062 if (!debug_active || !id->areas) 1063 return NULL; 1064 1065 numargs=debug_count_numargs(string); 1066 1067 if (debug_critical) { 1068 if (!spin_trylock_irqsave(&id->lock, flags)) 1069 return NULL; 1070 } else 1071 spin_lock_irqsave(&id->lock, flags); 1072 active = get_active_entry(id); 1073 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active); 1074 va_start(ap,string); 1075 curr_event->string=string; 1076 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1077 curr_event->args[idx]=va_arg(ap,long); 1078 va_end(ap); 1079 debug_finish_entry(id, active, level, 1); 1080 spin_unlock_irqrestore(&id->lock, flags); 1081 1082 return active; 1083 } 1084 1085 /* 1086 * debug_init: 1087 * - is called exactly once to initialize the debug feature 1088 */ 1089 1090 static int 1091 __init debug_init(void) 1092 { 1093 int rc = 0; 1094 1095 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1096 mutex_lock(&debug_mutex); 1097 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL); 1098 initialized = 1; 1099 mutex_unlock(&debug_mutex); 1100 1101 return rc; 1102 } 1103 1104 /* 1105 * debug_register_view: 1106 */ 1107 1108 int 1109 debug_register_view(debug_info_t * id, struct debug_view *view) 1110 { 1111 int rc = 0; 1112 int i; 1113 unsigned long flags; 1114 umode_t mode; 1115 struct dentry *pde; 1116 1117 if (!id) 1118 goto out; 1119 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1120 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1121 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1122 if (!view->input_proc) 1123 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1124 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1125 id , &debug_file_ops); 1126 if (!pde){ 1127 pr_err("Registering view %s/%s failed due to out of " 1128 "memory\n", id->name,view->name); 1129 rc = -1; 1130 goto out; 1131 } 1132 spin_lock_irqsave(&id->lock, flags); 1133 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1134 if (!id->views[i]) 1135 break; 1136 } 1137 if (i == DEBUG_MAX_VIEWS) { 1138 pr_err("Registering view %s/%s would exceed the maximum " 1139 "number of views %i\n", id->name, view->name, i); 1140 debugfs_remove(pde); 1141 rc = -1; 1142 } else { 1143 id->views[i] = view; 1144 id->debugfs_entries[i] = pde; 1145 } 1146 spin_unlock_irqrestore(&id->lock, flags); 1147 out: 1148 return rc; 1149 } 1150 1151 /* 1152 * debug_unregister_view: 1153 */ 1154 1155 int 1156 debug_unregister_view(debug_info_t * id, struct debug_view *view) 1157 { 1158 int rc = 0; 1159 int i; 1160 unsigned long flags; 1161 1162 if (!id) 1163 goto out; 1164 spin_lock_irqsave(&id->lock, flags); 1165 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1166 if (id->views[i] == view) 1167 break; 1168 } 1169 if (i == DEBUG_MAX_VIEWS) 1170 rc = -1; 1171 else { 1172 debugfs_remove(id->debugfs_entries[i]); 1173 id->views[i] = NULL; 1174 } 1175 spin_unlock_irqrestore(&id->lock, flags); 1176 out: 1177 return rc; 1178 } 1179 1180 static inline char * 1181 debug_get_user_string(const char __user *user_buf, size_t user_len) 1182 { 1183 char* buffer; 1184 1185 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1186 if (!buffer) 1187 return ERR_PTR(-ENOMEM); 1188 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1189 kfree(buffer); 1190 return ERR_PTR(-EFAULT); 1191 } 1192 /* got the string, now strip linefeed. */ 1193 if (buffer[user_len - 1] == '\n') 1194 buffer[user_len - 1] = 0; 1195 else 1196 buffer[user_len] = 0; 1197 return buffer; 1198 } 1199 1200 static inline int 1201 debug_get_uint(char *buf) 1202 { 1203 int rc; 1204 1205 buf = skip_spaces(buf); 1206 rc = simple_strtoul(buf, &buf, 10); 1207 if(*buf){ 1208 rc = -EINVAL; 1209 } 1210 return rc; 1211 } 1212 1213 /* 1214 * functions for debug-views 1215 *********************************** 1216 */ 1217 1218 /* 1219 * prints out actual debug level 1220 */ 1221 1222 static int 1223 debug_prolog_pages_fn(debug_info_t * id, 1224 struct debug_view *view, char *out_buf) 1225 { 1226 return sprintf(out_buf, "%i\n", id->pages_per_area); 1227 } 1228 1229 /* 1230 * reads new size (number of pages per debug area) 1231 */ 1232 1233 static int 1234 debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 1235 struct file *file, const char __user *user_buf, 1236 size_t user_len, loff_t * offset) 1237 { 1238 char *str; 1239 int rc,new_pages; 1240 1241 if (user_len > 0x10000) 1242 user_len = 0x10000; 1243 if (*offset != 0){ 1244 rc = -EPIPE; 1245 goto out; 1246 } 1247 str = debug_get_user_string(user_buf,user_len); 1248 if(IS_ERR(str)){ 1249 rc = PTR_ERR(str); 1250 goto out; 1251 } 1252 new_pages = debug_get_uint(str); 1253 if(new_pages < 0){ 1254 rc = -EINVAL; 1255 goto free_str; 1256 } 1257 rc = debug_set_size(id,id->nr_areas, new_pages); 1258 if(rc != 0){ 1259 rc = -EINVAL; 1260 goto free_str; 1261 } 1262 rc = user_len; 1263 free_str: 1264 kfree(str); 1265 out: 1266 *offset += user_len; 1267 return rc; /* number of input characters */ 1268 } 1269 1270 /* 1271 * prints out actual debug level 1272 */ 1273 1274 static int 1275 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf) 1276 { 1277 int rc = 0; 1278 1279 if(id->level == DEBUG_OFF_LEVEL) { 1280 rc = sprintf(out_buf,"-\n"); 1281 } 1282 else { 1283 rc = sprintf(out_buf, "%i\n", id->level); 1284 } 1285 return rc; 1286 } 1287 1288 /* 1289 * reads new debug level 1290 */ 1291 1292 static int 1293 debug_input_level_fn(debug_info_t * id, struct debug_view *view, 1294 struct file *file, const char __user *user_buf, 1295 size_t user_len, loff_t * offset) 1296 { 1297 char *str; 1298 int rc,new_level; 1299 1300 if (user_len > 0x10000) 1301 user_len = 0x10000; 1302 if (*offset != 0){ 1303 rc = -EPIPE; 1304 goto out; 1305 } 1306 str = debug_get_user_string(user_buf,user_len); 1307 if(IS_ERR(str)){ 1308 rc = PTR_ERR(str); 1309 goto out; 1310 } 1311 if(str[0] == '-'){ 1312 debug_set_level(id, DEBUG_OFF_LEVEL); 1313 rc = user_len; 1314 goto free_str; 1315 } else { 1316 new_level = debug_get_uint(str); 1317 } 1318 if(new_level < 0) { 1319 pr_warning("%s is not a valid level for a debug " 1320 "feature\n", str); 1321 rc = -EINVAL; 1322 } else { 1323 debug_set_level(id, new_level); 1324 rc = user_len; 1325 } 1326 free_str: 1327 kfree(str); 1328 out: 1329 *offset += user_len; 1330 return rc; /* number of input characters */ 1331 } 1332 1333 1334 /* 1335 * flushes debug areas 1336 */ 1337 1338 static void debug_flush(debug_info_t* id, int area) 1339 { 1340 unsigned long flags; 1341 int i,j; 1342 1343 if(!id || !id->areas) 1344 return; 1345 spin_lock_irqsave(&id->lock,flags); 1346 if(area == DEBUG_FLUSH_ALL){ 1347 id->active_area = 0; 1348 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1349 for (i = 0; i < id->nr_areas; i++) { 1350 id->active_pages[i] = 0; 1351 for(j = 0; j < id->pages_per_area; j++) { 1352 memset(id->areas[i][j], 0, PAGE_SIZE); 1353 } 1354 } 1355 } else if(area >= 0 && area < id->nr_areas) { 1356 id->active_entries[area] = 0; 1357 id->active_pages[area] = 0; 1358 for(i = 0; i < id->pages_per_area; i++) { 1359 memset(id->areas[area][i],0,PAGE_SIZE); 1360 } 1361 } 1362 spin_unlock_irqrestore(&id->lock,flags); 1363 } 1364 1365 /* 1366 * view function: flushes debug areas 1367 */ 1368 1369 static int 1370 debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 1371 struct file *file, const char __user *user_buf, 1372 size_t user_len, loff_t * offset) 1373 { 1374 char input_buf[1]; 1375 int rc = user_len; 1376 1377 if (user_len > 0x10000) 1378 user_len = 0x10000; 1379 if (*offset != 0){ 1380 rc = -EPIPE; 1381 goto out; 1382 } 1383 if (copy_from_user(input_buf, user_buf, 1)){ 1384 rc = -EFAULT; 1385 goto out; 1386 } 1387 if(input_buf[0] == '-') { 1388 debug_flush(id, DEBUG_FLUSH_ALL); 1389 goto out; 1390 } 1391 if (isdigit(input_buf[0])) { 1392 int area = ((int) input_buf[0] - (int) '0'); 1393 debug_flush(id, area); 1394 goto out; 1395 } 1396 1397 pr_info("Flushing debug data failed because %c is not a valid " 1398 "area\n", input_buf[0]); 1399 1400 out: 1401 *offset += user_len; 1402 return rc; /* number of input characters */ 1403 } 1404 1405 /* 1406 * prints debug header in raw format 1407 */ 1408 1409 static int 1410 debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 1411 int area, debug_entry_t * entry, char *out_buf) 1412 { 1413 int rc; 1414 1415 rc = sizeof(debug_entry_t); 1416 memcpy(out_buf,entry,sizeof(debug_entry_t)); 1417 return rc; 1418 } 1419 1420 /* 1421 * prints debug data in raw format 1422 */ 1423 1424 static int 1425 debug_raw_format_fn(debug_info_t * id, struct debug_view *view, 1426 char *out_buf, const char *in_buf) 1427 { 1428 int rc; 1429 1430 rc = id->buf_size; 1431 memcpy(out_buf, in_buf, id->buf_size); 1432 return rc; 1433 } 1434 1435 /* 1436 * prints debug data in hex/ascii format 1437 */ 1438 1439 static int 1440 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 1441 char *out_buf, const char *in_buf) 1442 { 1443 int i, rc = 0; 1444 1445 for (i = 0; i < id->buf_size; i++) { 1446 rc += sprintf(out_buf + rc, "%02x ", 1447 ((unsigned char *) in_buf)[i]); 1448 } 1449 rc += sprintf(out_buf + rc, "| "); 1450 for (i = 0; i < id->buf_size; i++) { 1451 unsigned char c = in_buf[i]; 1452 if (isascii(c) && isprint(c)) 1453 rc += sprintf(out_buf + rc, "%c", c); 1454 else 1455 rc += sprintf(out_buf + rc, "."); 1456 } 1457 rc += sprintf(out_buf + rc, "\n"); 1458 return rc; 1459 } 1460 1461 /* 1462 * prints header for debug entry 1463 */ 1464 1465 int 1466 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view, 1467 int area, debug_entry_t * entry, char *out_buf) 1468 { 1469 struct timespec time_spec; 1470 char *except_str; 1471 unsigned long caller; 1472 int rc = 0; 1473 unsigned int level; 1474 1475 level = entry->id.fields.level; 1476 stck_to_timespec(entry->id.stck, &time_spec); 1477 1478 if (entry->id.fields.exception) 1479 except_str = "*"; 1480 else 1481 except_str = "-"; 1482 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN; 1483 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ", 1484 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level, 1485 except_str, entry->id.fields.cpuid, (void *) caller); 1486 return rc; 1487 } 1488 1489 /* 1490 * prints debug data sprintf-formated: 1491 * debug_sprinf_event/exception calls must be used together with this view 1492 */ 1493 1494 #define DEBUG_SPRINTF_MAX_ARGS 10 1495 1496 static int 1497 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 1498 char *out_buf, debug_sprintf_entry_t *curr_event) 1499 { 1500 int num_longs, num_used_args = 0,i, rc = 0; 1501 int index[DEBUG_SPRINTF_MAX_ARGS]; 1502 1503 /* count of longs fit into one entry */ 1504 num_longs = id->buf_size / sizeof(long); 1505 1506 if(num_longs < 1) 1507 goto out; /* bufsize of entry too small */ 1508 if(num_longs == 1) { 1509 /* no args, we use only the string */ 1510 strcpy(out_buf, curr_event->string); 1511 rc = strlen(curr_event->string); 1512 goto out; 1513 } 1514 1515 /* number of arguments used for sprintf (without the format string) */ 1516 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1517 1518 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1519 1520 for(i = 0; i < num_used_args; i++) 1521 index[i] = i; 1522 1523 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1524 curr_event->args[index[1]], curr_event->args[index[2]], 1525 curr_event->args[index[3]], curr_event->args[index[4]], 1526 curr_event->args[index[5]], curr_event->args[index[6]], 1527 curr_event->args[index[7]], curr_event->args[index[8]], 1528 curr_event->args[index[9]]); 1529 1530 out: 1531 1532 return rc; 1533 } 1534 1535 /* 1536 * clean up module 1537 */ 1538 static void __exit debug_exit(void) 1539 { 1540 debugfs_remove(debug_debugfs_root_entry); 1541 unregister_sysctl_table(s390dbf_sysctl_header); 1542 return; 1543 } 1544 1545 /* 1546 * module definitions 1547 */ 1548 postcore_initcall(debug_init); 1549 module_exit(debug_exit); 1550 MODULE_LICENSE("GPL"); 1551 1552 EXPORT_SYMBOL(debug_register); 1553 EXPORT_SYMBOL(debug_unregister); 1554 EXPORT_SYMBOL(debug_set_level); 1555 EXPORT_SYMBOL(debug_stop_all); 1556 EXPORT_SYMBOL(debug_register_view); 1557 EXPORT_SYMBOL(debug_unregister_view); 1558 EXPORT_SYMBOL(debug_event_common); 1559 EXPORT_SYMBOL(debug_exception_common); 1560 EXPORT_SYMBOL(debug_hex_ascii_view); 1561 EXPORT_SYMBOL(debug_raw_view); 1562 EXPORT_SYMBOL(debug_dflt_header_fn); 1563 EXPORT_SYMBOL(debug_sprintf_view); 1564 EXPORT_SYMBOL(debug_sprintf_exception); 1565 EXPORT_SYMBOL(debug_sprintf_event); 1566