1 /* 2 * arch/s390/kernel/debug.c 3 * S/390 debug facility 4 * 5 * Copyright IBM Corp. 1999, 2012 6 * 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/string.h> 22 #include <linux/sysctl.h> 23 #include <asm/uaccess.h> 24 #include <linux/module.h> 25 #include <linux/init.h> 26 #include <linux/fs.h> 27 #include <linux/debugfs.h> 28 29 #include <asm/debug.h> 30 31 #define DEBUG_PROLOG_ENTRY -1 32 33 #define ALL_AREAS 0 /* copy all debug areas */ 34 #define NO_AREAS 1 /* copy no debug areas */ 35 36 /* typedefs */ 37 38 typedef struct file_private_info { 39 loff_t offset; /* offset of last read in file */ 40 int act_area; /* number of last formated area */ 41 int act_page; /* act page in given area */ 42 int act_entry; /* last formated entry (offset */ 43 /* relative to beginning of last */ 44 /* formated page) */ 45 size_t act_entry_offset; /* up to this offset we copied */ 46 /* in last read the last formated */ 47 /* entry to userland */ 48 char temp_buf[2048]; /* buffer for output */ 49 debug_info_t *debug_info_org; /* original debug information */ 50 debug_info_t *debug_info_snap; /* snapshot of debug information */ 51 struct debug_view *view; /* used view of debug info */ 52 } file_private_info_t; 53 54 typedef struct 55 { 56 char *string; 57 /* 58 * This assumes that all args are converted into longs 59 * on L/390 this is the case for all types of parameter 60 * except of floats, and long long (32 bit) 61 * 62 */ 63 long args[0]; 64 } debug_sprintf_entry_t; 65 66 67 /* internal function prototyes */ 68 69 static int debug_init(void); 70 static ssize_t debug_output(struct file *file, char __user *user_buf, 71 size_t user_len, loff_t * offset); 72 static ssize_t debug_input(struct file *file, const char __user *user_buf, 73 size_t user_len, loff_t * offset); 74 static int debug_open(struct inode *inode, struct file *file); 75 static int debug_close(struct inode *inode, struct file *file); 76 static debug_info_t *debug_info_create(const char *name, int pages_per_area, 77 int nr_areas, int buf_size, umode_t mode); 78 static void debug_info_get(debug_info_t *); 79 static void debug_info_put(debug_info_t *); 80 static int debug_prolog_level_fn(debug_info_t * id, 81 struct debug_view *view, char *out_buf); 82 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view, 83 struct file *file, const char __user *user_buf, 84 size_t user_buf_size, loff_t * offset); 85 static int debug_prolog_pages_fn(debug_info_t * id, 86 struct debug_view *view, char *out_buf); 87 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 88 struct file *file, const char __user *user_buf, 89 size_t user_buf_size, loff_t * offset); 90 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 91 struct file *file, const char __user *user_buf, 92 size_t user_buf_size, loff_t * offset); 93 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 94 char *out_buf, const char *in_buf); 95 static int debug_raw_format_fn(debug_info_t * id, 96 struct debug_view *view, char *out_buf, 97 const char *in_buf); 98 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 99 int area, debug_entry_t * entry, char *out_buf); 100 101 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 102 char *out_buf, debug_sprintf_entry_t *curr_event); 103 104 /* globals */ 105 106 struct debug_view debug_raw_view = { 107 "raw", 108 NULL, 109 &debug_raw_header_fn, 110 &debug_raw_format_fn, 111 NULL, 112 NULL 113 }; 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 }; 123 124 static struct debug_view debug_level_view = { 125 "level", 126 &debug_prolog_level_fn, 127 NULL, 128 NULL, 129 &debug_input_level_fn, 130 NULL 131 }; 132 133 static struct debug_view debug_pages_view = { 134 "pages", 135 &debug_prolog_pages_fn, 136 NULL, 137 NULL, 138 &debug_input_pages_fn, 139 NULL 140 }; 141 142 static struct debug_view debug_flush_view = { 143 "flush", 144 NULL, 145 NULL, 146 NULL, 147 &debug_input_flush_fn, 148 NULL 149 }; 150 151 struct debug_view debug_sprintf_view = { 152 "sprintf", 153 NULL, 154 &debug_dflt_header_fn, 155 (debug_format_proc_t*)&debug_sprintf_format_fn, 156 NULL, 157 NULL 158 }; 159 160 /* used by dump analysis tools to determine version of debug feature */ 161 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 162 163 /* static globals */ 164 165 static debug_info_t *debug_area_first = NULL; 166 static debug_info_t *debug_area_last = NULL; 167 static DEFINE_MUTEX(debug_mutex); 168 169 static int initialized; 170 static int debug_critical; 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 .llseek = no_llseek, 179 }; 180 181 static struct dentry *debug_debugfs_root_entry; 182 183 /* functions */ 184 185 /* 186 * debug_areas_alloc 187 * - Debug areas are implemented as a threedimensonal array: 188 * areas[areanumber][pagenumber][pageoffset] 189 */ 190 191 static debug_entry_t*** 192 debug_areas_alloc(int pages_per_area, int nr_areas) 193 { 194 debug_entry_t*** areas; 195 int i,j; 196 197 areas = kmalloc(nr_areas * 198 sizeof(debug_entry_t**), 199 GFP_KERNEL); 200 if (!areas) 201 goto fail_malloc_areas; 202 for (i = 0; i < nr_areas; i++) { 203 areas[i] = kmalloc(pages_per_area * 204 sizeof(debug_entry_t*),GFP_KERNEL); 205 if (!areas[i]) { 206 goto fail_malloc_areas2; 207 } 208 for(j = 0; j < pages_per_area; j++) { 209 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); 210 if(!areas[i][j]) { 211 for(j--; j >=0 ; j--) { 212 kfree(areas[i][j]); 213 } 214 kfree(areas[i]); 215 goto fail_malloc_areas2; 216 } 217 } 218 } 219 return areas; 220 221 fail_malloc_areas2: 222 for(i--; i >= 0; i--){ 223 for(j=0; j < pages_per_area;j++){ 224 kfree(areas[i][j]); 225 } 226 kfree(areas[i]); 227 } 228 kfree(areas); 229 fail_malloc_areas: 230 return NULL; 231 232 } 233 234 235 /* 236 * debug_info_alloc 237 * - alloc new debug-info 238 */ 239 240 static debug_info_t* 241 debug_info_alloc(const char *name, int pages_per_area, int nr_areas, 242 int buf_size, int level, int mode) 243 { 244 debug_info_t* rc; 245 246 /* alloc everything */ 247 248 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); 249 if(!rc) 250 goto fail_malloc_rc; 251 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 252 if(!rc->active_entries) 253 goto fail_malloc_active_entries; 254 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 255 if(!rc->active_pages) 256 goto fail_malloc_active_pages; 257 if((mode == ALL_AREAS) && (pages_per_area != 0)){ 258 rc->areas = debug_areas_alloc(pages_per_area, nr_areas); 259 if(!rc->areas) 260 goto fail_malloc_areas; 261 } else { 262 rc->areas = NULL; 263 } 264 265 /* initialize members */ 266 267 spin_lock_init(&rc->lock); 268 rc->pages_per_area = pages_per_area; 269 rc->nr_areas = nr_areas; 270 rc->active_area = 0; 271 rc->level = level; 272 rc->buf_size = buf_size; 273 rc->entry_size = sizeof(debug_entry_t) + buf_size; 274 strlcpy(rc->name, name, sizeof(rc->name)); 275 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); 276 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS * 277 sizeof(struct dentry*)); 278 atomic_set(&(rc->ref_count), 0); 279 280 return rc; 281 282 fail_malloc_areas: 283 kfree(rc->active_pages); 284 fail_malloc_active_pages: 285 kfree(rc->active_entries); 286 fail_malloc_active_entries: 287 kfree(rc); 288 fail_malloc_rc: 289 return NULL; 290 } 291 292 /* 293 * debug_areas_free 294 * - free all debug areas 295 */ 296 297 static void 298 debug_areas_free(debug_info_t* db_info) 299 { 300 int i,j; 301 302 if(!db_info->areas) 303 return; 304 for (i = 0; i < db_info->nr_areas; i++) { 305 for(j = 0; j < db_info->pages_per_area; j++) { 306 kfree(db_info->areas[i][j]); 307 } 308 kfree(db_info->areas[i]); 309 } 310 kfree(db_info->areas); 311 db_info->areas = NULL; 312 } 313 314 /* 315 * debug_info_free 316 * - free memory debug-info 317 */ 318 319 static void 320 debug_info_free(debug_info_t* db_info){ 321 debug_areas_free(db_info); 322 kfree(db_info->active_entries); 323 kfree(db_info->active_pages); 324 kfree(db_info); 325 } 326 327 /* 328 * debug_info_create 329 * - create new debug-info 330 */ 331 332 static debug_info_t* 333 debug_info_create(const char *name, int pages_per_area, int nr_areas, 334 int buf_size, umode_t mode) 335 { 336 debug_info_t* rc; 337 338 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, 339 DEBUG_DEFAULT_LEVEL, ALL_AREAS); 340 if(!rc) 341 goto out; 342 343 rc->mode = mode & ~S_IFMT; 344 345 /* create root directory */ 346 rc->debugfs_root_entry = debugfs_create_dir(rc->name, 347 debug_debugfs_root_entry); 348 349 /* append new element to linked list */ 350 if (!debug_area_first) { 351 /* first element in list */ 352 debug_area_first = rc; 353 rc->prev = NULL; 354 } else { 355 /* append element to end of list */ 356 debug_area_last->next = rc; 357 rc->prev = debug_area_last; 358 } 359 debug_area_last = rc; 360 rc->next = NULL; 361 362 debug_info_get(rc); 363 out: 364 return rc; 365 } 366 367 /* 368 * debug_info_copy 369 * - copy debug-info 370 */ 371 372 static debug_info_t* 373 debug_info_copy(debug_info_t* in, int mode) 374 { 375 int i,j; 376 debug_info_t* rc; 377 unsigned long flags; 378 379 /* get a consistent copy of the debug areas */ 380 do { 381 rc = debug_info_alloc(in->name, in->pages_per_area, 382 in->nr_areas, in->buf_size, in->level, mode); 383 spin_lock_irqsave(&in->lock, flags); 384 if(!rc) 385 goto out; 386 /* has something changed in the meantime ? */ 387 if((rc->pages_per_area == in->pages_per_area) && 388 (rc->nr_areas == in->nr_areas)) { 389 break; 390 } 391 spin_unlock_irqrestore(&in->lock, flags); 392 debug_info_free(rc); 393 } while (1); 394 395 if (mode == NO_AREAS) 396 goto out; 397 398 for(i = 0; i < in->nr_areas; i++){ 399 for(j = 0; j < in->pages_per_area; j++) { 400 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE); 401 } 402 } 403 out: 404 spin_unlock_irqrestore(&in->lock, flags); 405 return rc; 406 } 407 408 /* 409 * debug_info_get 410 * - increments reference count for debug-info 411 */ 412 413 static void 414 debug_info_get(debug_info_t * db_info) 415 { 416 if (db_info) 417 atomic_inc(&db_info->ref_count); 418 } 419 420 /* 421 * debug_info_put: 422 * - decreases reference count for debug-info and frees it if necessary 423 */ 424 425 static void 426 debug_info_put(debug_info_t *db_info) 427 { 428 int i; 429 430 if (!db_info) 431 return; 432 if (atomic_dec_and_test(&db_info->ref_count)) { 433 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 434 if (!db_info->views[i]) 435 continue; 436 debugfs_remove(db_info->debugfs_entries[i]); 437 } 438 debugfs_remove(db_info->debugfs_root_entry); 439 if(db_info == debug_area_first) 440 debug_area_first = db_info->next; 441 if(db_info == debug_area_last) 442 debug_area_last = db_info->prev; 443 if(db_info->prev) db_info->prev->next = db_info->next; 444 if(db_info->next) db_info->next->prev = db_info->prev; 445 debug_info_free(db_info); 446 } 447 } 448 449 /* 450 * debug_format_entry: 451 * - format one debug entry and return size of formated data 452 */ 453 454 static int 455 debug_format_entry(file_private_info_t *p_info) 456 { 457 debug_info_t *id_snap = p_info->debug_info_snap; 458 struct debug_view *view = p_info->view; 459 debug_entry_t *act_entry; 460 size_t len = 0; 461 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 462 /* print prolog */ 463 if (view->prolog_proc) 464 len += view->prolog_proc(id_snap,view,p_info->temp_buf); 465 goto out; 466 } 467 if (!id_snap->areas) /* this is true, if we have a prolog only view */ 468 goto out; /* or if 'pages_per_area' is 0 */ 469 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area] 470 [p_info->act_page] + p_info->act_entry); 471 472 if (act_entry->id.stck == 0LL) 473 goto out; /* empty entry */ 474 if (view->header_proc) 475 len += view->header_proc(id_snap, view, p_info->act_area, 476 act_entry, p_info->temp_buf + len); 477 if (view->format_proc) 478 len += view->format_proc(id_snap, view, p_info->temp_buf + len, 479 DEBUG_DATA(act_entry)); 480 out: 481 return len; 482 } 483 484 /* 485 * debug_next_entry: 486 * - goto next entry in p_info 487 */ 488 489 static inline int 490 debug_next_entry(file_private_info_t *p_info) 491 { 492 debug_info_t *id; 493 494 id = p_info->debug_info_snap; 495 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 496 p_info->act_entry = 0; 497 p_info->act_page = 0; 498 goto out; 499 } 500 if(!id->areas) 501 return 1; 502 p_info->act_entry += id->entry_size; 503 /* switch to next page, if we reached the end of the page */ 504 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){ 505 /* next page */ 506 p_info->act_entry = 0; 507 p_info->act_page += 1; 508 if((p_info->act_page % id->pages_per_area) == 0) { 509 /* next area */ 510 p_info->act_area++; 511 p_info->act_page=0; 512 } 513 if(p_info->act_area >= id->nr_areas) 514 return 1; 515 } 516 out: 517 return 0; 518 } 519 520 /* 521 * debug_output: 522 * - called for user read() 523 * - copies formated debug entries to the user buffer 524 */ 525 526 static ssize_t 527 debug_output(struct file *file, /* file descriptor */ 528 char __user *user_buf, /* user buffer */ 529 size_t len, /* length of buffer */ 530 loff_t *offset) /* offset in the file */ 531 { 532 size_t count = 0; 533 size_t entry_offset; 534 file_private_info_t *p_info; 535 536 p_info = ((file_private_info_t *) file->private_data); 537 if (*offset != p_info->offset) 538 return -EPIPE; 539 if(p_info->act_area >= p_info->debug_info_snap->nr_areas) 540 return 0; 541 entry_offset = p_info->act_entry_offset; 542 while(count < len){ 543 int formatted_line_size; 544 int formatted_line_residue; 545 int user_buf_residue; 546 size_t copy_size; 547 548 formatted_line_size = debug_format_entry(p_info); 549 formatted_line_residue = formatted_line_size - entry_offset; 550 user_buf_residue = len-count; 551 copy_size = min(user_buf_residue, formatted_line_residue); 552 if(copy_size){ 553 if (copy_to_user(user_buf + count, p_info->temp_buf 554 + entry_offset, copy_size)) 555 return -EFAULT; 556 count += copy_size; 557 entry_offset += copy_size; 558 } 559 if(copy_size == formatted_line_residue){ 560 entry_offset = 0; 561 if(debug_next_entry(p_info)) 562 goto out; 563 } 564 } 565 out: 566 p_info->offset = *offset + count; 567 p_info->act_entry_offset = entry_offset; 568 *offset = p_info->offset; 569 return count; 570 } 571 572 /* 573 * debug_input: 574 * - called for user write() 575 * - calls input function of view 576 */ 577 578 static ssize_t 579 debug_input(struct file *file, const char __user *user_buf, size_t length, 580 loff_t *offset) 581 { 582 int rc = 0; 583 file_private_info_t *p_info; 584 585 mutex_lock(&debug_mutex); 586 p_info = ((file_private_info_t *) file->private_data); 587 if (p_info->view->input_proc) 588 rc = p_info->view->input_proc(p_info->debug_info_org, 589 p_info->view, file, user_buf, 590 length, offset); 591 else 592 rc = -EPERM; 593 mutex_unlock(&debug_mutex); 594 return rc; /* number of input characters */ 595 } 596 597 /* 598 * debug_open: 599 * - called for user open() 600 * - copies formated output to private_data area of the file 601 * handle 602 */ 603 604 static int 605 debug_open(struct inode *inode, struct file *file) 606 { 607 int i, rc = 0; 608 file_private_info_t *p_info; 609 debug_info_t *debug_info, *debug_info_snapshot; 610 611 mutex_lock(&debug_mutex); 612 debug_info = file->f_path.dentry->d_inode->i_private; 613 /* find debug view */ 614 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 615 if (!debug_info->views[i]) 616 continue; 617 else if (debug_info->debugfs_entries[i] == 618 file->f_path.dentry) { 619 goto found; /* found view ! */ 620 } 621 } 622 /* no entry found */ 623 rc = -EINVAL; 624 goto out; 625 626 found: 627 628 /* Make snapshot of current debug areas to get it consistent. */ 629 /* To copy all the areas is only needed, if we have a view which */ 630 /* formats the debug areas. */ 631 632 if(!debug_info->views[i]->format_proc && 633 !debug_info->views[i]->header_proc){ 634 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS); 635 } else { 636 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS); 637 } 638 639 if(!debug_info_snapshot){ 640 rc = -ENOMEM; 641 goto out; 642 } 643 p_info = kmalloc(sizeof(file_private_info_t), 644 GFP_KERNEL); 645 if(!p_info){ 646 debug_info_free(debug_info_snapshot); 647 rc = -ENOMEM; 648 goto out; 649 } 650 p_info->offset = 0; 651 p_info->debug_info_snap = debug_info_snapshot; 652 p_info->debug_info_org = debug_info; 653 p_info->view = debug_info->views[i]; 654 p_info->act_area = 0; 655 p_info->act_page = 0; 656 p_info->act_entry = DEBUG_PROLOG_ENTRY; 657 p_info->act_entry_offset = 0; 658 file->private_data = p_info; 659 debug_info_get(debug_info); 660 nonseekable_open(inode, file); 661 out: 662 mutex_unlock(&debug_mutex); 663 return rc; 664 } 665 666 /* 667 * debug_close: 668 * - called for user close() 669 * - deletes private_data area of the file handle 670 */ 671 672 static int 673 debug_close(struct inode *inode, struct file *file) 674 { 675 file_private_info_t *p_info; 676 p_info = (file_private_info_t *) file->private_data; 677 if(p_info->debug_info_snap) 678 debug_info_free(p_info->debug_info_snap); 679 debug_info_put(p_info->debug_info_org); 680 kfree(file->private_data); 681 return 0; /* success */ 682 } 683 684 /* 685 * debug_register_mode: 686 * - Creates and initializes debug area for the caller 687 * The mode parameter allows to specify access rights for the s390dbf files 688 * - Returns handle for debug area 689 */ 690 691 debug_info_t *debug_register_mode(const char *name, int pages_per_area, 692 int nr_areas, int buf_size, umode_t mode, 693 uid_t uid, gid_t gid) 694 { 695 debug_info_t *rc = NULL; 696 697 /* Since debugfs currently does not support uid/gid other than root, */ 698 /* we do not allow gid/uid != 0 until we get support for that. */ 699 if ((uid != 0) || (gid != 0)) 700 pr_warning("Root becomes the owner of all s390dbf files " 701 "in sysfs\n"); 702 BUG_ON(!initialized); 703 mutex_lock(&debug_mutex); 704 705 /* create new debug_info */ 706 707 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 708 if(!rc) 709 goto out; 710 debug_register_view(rc, &debug_level_view); 711 debug_register_view(rc, &debug_flush_view); 712 debug_register_view(rc, &debug_pages_view); 713 out: 714 if (!rc){ 715 pr_err("Registering debug feature %s failed\n", name); 716 } 717 mutex_unlock(&debug_mutex); 718 return rc; 719 } 720 EXPORT_SYMBOL(debug_register_mode); 721 722 /* 723 * debug_register: 724 * - creates and initializes debug area for the caller 725 * - returns handle for debug area 726 */ 727 728 debug_info_t *debug_register(const char *name, int pages_per_area, 729 int nr_areas, int buf_size) 730 { 731 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 732 S_IRUSR | S_IWUSR, 0, 0); 733 } 734 735 /* 736 * debug_unregister: 737 * - give back debug area 738 */ 739 740 void 741 debug_unregister(debug_info_t * id) 742 { 743 if (!id) 744 goto out; 745 mutex_lock(&debug_mutex); 746 debug_info_put(id); 747 mutex_unlock(&debug_mutex); 748 749 out: 750 return; 751 } 752 753 /* 754 * debug_set_size: 755 * - set area size (number of pages) and number of areas 756 */ 757 static int 758 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area) 759 { 760 unsigned long flags; 761 debug_entry_t *** new_areas; 762 int rc=0; 763 764 if(!id || (nr_areas <= 0) || (pages_per_area < 0)) 765 return -EINVAL; 766 if(pages_per_area > 0){ 767 new_areas = debug_areas_alloc(pages_per_area, nr_areas); 768 if(!new_areas) { 769 pr_info("Allocating memory for %i pages failed\n", 770 pages_per_area); 771 rc = -ENOMEM; 772 goto out; 773 } 774 } else { 775 new_areas = NULL; 776 } 777 spin_lock_irqsave(&id->lock,flags); 778 debug_areas_free(id); 779 id->areas = new_areas; 780 id->nr_areas = nr_areas; 781 id->pages_per_area = pages_per_area; 782 id->active_area = 0; 783 memset(id->active_entries,0,sizeof(int)*id->nr_areas); 784 memset(id->active_pages, 0, sizeof(int)*id->nr_areas); 785 spin_unlock_irqrestore(&id->lock,flags); 786 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area); 787 out: 788 return rc; 789 } 790 791 /* 792 * debug_set_level: 793 * - set actual debug level 794 */ 795 796 void 797 debug_set_level(debug_info_t* id, int new_level) 798 { 799 unsigned long flags; 800 if(!id) 801 return; 802 spin_lock_irqsave(&id->lock,flags); 803 if(new_level == DEBUG_OFF_LEVEL){ 804 id->level = DEBUG_OFF_LEVEL; 805 pr_info("%s: switched off\n",id->name); 806 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 807 pr_info("%s: level %i is out of range (%i - %i)\n", 808 id->name, new_level, 0, DEBUG_MAX_LEVEL); 809 } else { 810 id->level = new_level; 811 } 812 spin_unlock_irqrestore(&id->lock,flags); 813 } 814 815 816 /* 817 * proceed_active_entry: 818 * - set active entry to next in the ring buffer 819 */ 820 821 static inline void 822 proceed_active_entry(debug_info_t * id) 823 { 824 if ((id->active_entries[id->active_area] += id->entry_size) 825 > (PAGE_SIZE - id->entry_size)){ 826 id->active_entries[id->active_area] = 0; 827 id->active_pages[id->active_area] = 828 (id->active_pages[id->active_area] + 1) % 829 id->pages_per_area; 830 } 831 } 832 833 /* 834 * proceed_active_area: 835 * - set active area to next in the ring buffer 836 */ 837 838 static inline void 839 proceed_active_area(debug_info_t * id) 840 { 841 id->active_area++; 842 id->active_area = id->active_area % id->nr_areas; 843 } 844 845 /* 846 * get_active_entry: 847 */ 848 849 static inline debug_entry_t* 850 get_active_entry(debug_info_t * id) 851 { 852 return (debug_entry_t *) (((char *) id->areas[id->active_area] 853 [id->active_pages[id->active_area]]) + 854 id->active_entries[id->active_area]); 855 } 856 857 /* 858 * debug_finish_entry: 859 * - set timestamp, caller address, cpu number etc. 860 */ 861 862 static inline void 863 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level, 864 int exception) 865 { 866 active->id.stck = get_clock(); 867 active->id.fields.cpuid = smp_processor_id(); 868 active->caller = __builtin_return_address(0); 869 active->id.fields.exception = exception; 870 active->id.fields.level = level; 871 proceed_active_entry(id); 872 if(exception) 873 proceed_active_area(id); 874 } 875 876 static int debug_stoppable=1; 877 static int debug_active=1; 878 879 #define CTL_S390DBF_STOPPABLE 5678 880 #define CTL_S390DBF_ACTIVE 5679 881 882 /* 883 * proc handler for the running debug_active sysctl 884 * always allow read, allow write only if debug_stoppable is set or 885 * if debug_active is already off 886 */ 887 static int 888 s390dbf_procactive(ctl_table *table, int write, 889 void __user *buffer, size_t *lenp, loff_t *ppos) 890 { 891 if (!write || debug_stoppable || !debug_active) 892 return proc_dointvec(table, write, buffer, lenp, ppos); 893 else 894 return 0; 895 } 896 897 898 static struct ctl_table s390dbf_table[] = { 899 { 900 .procname = "debug_stoppable", 901 .data = &debug_stoppable, 902 .maxlen = sizeof(int), 903 .mode = S_IRUGO | S_IWUSR, 904 .proc_handler = proc_dointvec, 905 }, 906 { 907 .procname = "debug_active", 908 .data = &debug_active, 909 .maxlen = sizeof(int), 910 .mode = S_IRUGO | S_IWUSR, 911 .proc_handler = s390dbf_procactive, 912 }, 913 { } 914 }; 915 916 static struct ctl_table s390dbf_dir_table[] = { 917 { 918 .procname = "s390dbf", 919 .maxlen = 0, 920 .mode = S_IRUGO | S_IXUGO, 921 .child = s390dbf_table, 922 }, 923 { } 924 }; 925 926 static struct ctl_table_header *s390dbf_sysctl_header; 927 928 void 929 debug_stop_all(void) 930 { 931 if (debug_stoppable) 932 debug_active = 0; 933 } 934 935 936 void debug_set_critical(void) 937 { 938 debug_critical = 1; 939 } 940 941 /* 942 * debug_event_common: 943 * - write debug entry with given size 944 */ 945 946 debug_entry_t* 947 debug_event_common(debug_info_t * id, int level, const void *buf, int len) 948 { 949 unsigned long flags; 950 debug_entry_t *active; 951 952 if (!debug_active || !id->areas) 953 return NULL; 954 if (debug_critical) { 955 if (!spin_trylock_irqsave(&id->lock, flags)) 956 return NULL; 957 } else 958 spin_lock_irqsave(&id->lock, flags); 959 active = get_active_entry(id); 960 memset(DEBUG_DATA(active), 0, id->buf_size); 961 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 962 debug_finish_entry(id, active, level, 0); 963 spin_unlock_irqrestore(&id->lock, flags); 964 965 return active; 966 } 967 968 /* 969 * debug_exception_common: 970 * - write debug entry with given size and switch to next debug area 971 */ 972 973 debug_entry_t 974 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len) 975 { 976 unsigned long flags; 977 debug_entry_t *active; 978 979 if (!debug_active || !id->areas) 980 return NULL; 981 if (debug_critical) { 982 if (!spin_trylock_irqsave(&id->lock, flags)) 983 return NULL; 984 } else 985 spin_lock_irqsave(&id->lock, flags); 986 active = get_active_entry(id); 987 memset(DEBUG_DATA(active), 0, id->buf_size); 988 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 989 debug_finish_entry(id, active, level, 1); 990 spin_unlock_irqrestore(&id->lock, flags); 991 992 return active; 993 } 994 995 /* 996 * counts arguments in format string for sprintf view 997 */ 998 999 static inline int 1000 debug_count_numargs(char *string) 1001 { 1002 int numargs=0; 1003 1004 while(*string) { 1005 if(*string++=='%') 1006 numargs++; 1007 } 1008 return(numargs); 1009 } 1010 1011 /* 1012 * debug_sprintf_event: 1013 */ 1014 1015 debug_entry_t* 1016 debug_sprintf_event(debug_info_t* id, int level,char *string,...) 1017 { 1018 va_list ap; 1019 int numargs,idx; 1020 unsigned long flags; 1021 debug_sprintf_entry_t *curr_event; 1022 debug_entry_t *active; 1023 1024 if((!id) || (level > id->level)) 1025 return NULL; 1026 if (!debug_active || !id->areas) 1027 return NULL; 1028 numargs=debug_count_numargs(string); 1029 1030 if (debug_critical) { 1031 if (!spin_trylock_irqsave(&id->lock, flags)) 1032 return NULL; 1033 } else 1034 spin_lock_irqsave(&id->lock, flags); 1035 active = get_active_entry(id); 1036 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active); 1037 va_start(ap,string); 1038 curr_event->string=string; 1039 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1040 curr_event->args[idx]=va_arg(ap,long); 1041 va_end(ap); 1042 debug_finish_entry(id, active, level, 0); 1043 spin_unlock_irqrestore(&id->lock, flags); 1044 1045 return active; 1046 } 1047 1048 /* 1049 * debug_sprintf_exception: 1050 */ 1051 1052 debug_entry_t* 1053 debug_sprintf_exception(debug_info_t* id, int level,char *string,...) 1054 { 1055 va_list ap; 1056 int numargs,idx; 1057 unsigned long flags; 1058 debug_sprintf_entry_t *curr_event; 1059 debug_entry_t *active; 1060 1061 if((!id) || (level > id->level)) 1062 return NULL; 1063 if (!debug_active || !id->areas) 1064 return NULL; 1065 1066 numargs=debug_count_numargs(string); 1067 1068 if (debug_critical) { 1069 if (!spin_trylock_irqsave(&id->lock, flags)) 1070 return NULL; 1071 } else 1072 spin_lock_irqsave(&id->lock, flags); 1073 active = get_active_entry(id); 1074 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active); 1075 va_start(ap,string); 1076 curr_event->string=string; 1077 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1078 curr_event->args[idx]=va_arg(ap,long); 1079 va_end(ap); 1080 debug_finish_entry(id, active, level, 1); 1081 spin_unlock_irqrestore(&id->lock, flags); 1082 1083 return active; 1084 } 1085 1086 /* 1087 * debug_init: 1088 * - is called exactly once to initialize the debug feature 1089 */ 1090 1091 static int 1092 __init debug_init(void) 1093 { 1094 int rc = 0; 1095 1096 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1097 mutex_lock(&debug_mutex); 1098 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL); 1099 initialized = 1; 1100 mutex_unlock(&debug_mutex); 1101 1102 return rc; 1103 } 1104 1105 /* 1106 * debug_register_view: 1107 */ 1108 1109 int 1110 debug_register_view(debug_info_t * id, struct debug_view *view) 1111 { 1112 int rc = 0; 1113 int i; 1114 unsigned long flags; 1115 umode_t mode; 1116 struct dentry *pde; 1117 1118 if (!id) 1119 goto out; 1120 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1121 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1122 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1123 if (!view->input_proc) 1124 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1125 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1126 id , &debug_file_ops); 1127 if (!pde){ 1128 pr_err("Registering view %s/%s failed due to out of " 1129 "memory\n", id->name,view->name); 1130 rc = -1; 1131 goto out; 1132 } 1133 spin_lock_irqsave(&id->lock, flags); 1134 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1135 if (!id->views[i]) 1136 break; 1137 } 1138 if (i == DEBUG_MAX_VIEWS) { 1139 pr_err("Registering view %s/%s would exceed the maximum " 1140 "number of views %i\n", id->name, view->name, i); 1141 debugfs_remove(pde); 1142 rc = -1; 1143 } else { 1144 id->views[i] = view; 1145 id->debugfs_entries[i] = pde; 1146 } 1147 spin_unlock_irqrestore(&id->lock, flags); 1148 out: 1149 return rc; 1150 } 1151 1152 /* 1153 * debug_unregister_view: 1154 */ 1155 1156 int 1157 debug_unregister_view(debug_info_t * id, struct debug_view *view) 1158 { 1159 int rc = 0; 1160 int i; 1161 unsigned long flags; 1162 1163 if (!id) 1164 goto out; 1165 spin_lock_irqsave(&id->lock, flags); 1166 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1167 if (id->views[i] == view) 1168 break; 1169 } 1170 if (i == DEBUG_MAX_VIEWS) 1171 rc = -1; 1172 else { 1173 debugfs_remove(id->debugfs_entries[i]); 1174 id->views[i] = NULL; 1175 } 1176 spin_unlock_irqrestore(&id->lock, flags); 1177 out: 1178 return rc; 1179 } 1180 1181 static inline char * 1182 debug_get_user_string(const char __user *user_buf, size_t user_len) 1183 { 1184 char* buffer; 1185 1186 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1187 if (!buffer) 1188 return ERR_PTR(-ENOMEM); 1189 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1190 kfree(buffer); 1191 return ERR_PTR(-EFAULT); 1192 } 1193 /* got the string, now strip linefeed. */ 1194 if (buffer[user_len - 1] == '\n') 1195 buffer[user_len - 1] = 0; 1196 else 1197 buffer[user_len] = 0; 1198 return buffer; 1199 } 1200 1201 static inline int 1202 debug_get_uint(char *buf) 1203 { 1204 int rc; 1205 1206 buf = skip_spaces(buf); 1207 rc = simple_strtoul(buf, &buf, 10); 1208 if(*buf){ 1209 rc = -EINVAL; 1210 } 1211 return rc; 1212 } 1213 1214 /* 1215 * functions for debug-views 1216 *********************************** 1217 */ 1218 1219 /* 1220 * prints out actual debug level 1221 */ 1222 1223 static int 1224 debug_prolog_pages_fn(debug_info_t * id, 1225 struct debug_view *view, char *out_buf) 1226 { 1227 return sprintf(out_buf, "%i\n", id->pages_per_area); 1228 } 1229 1230 /* 1231 * reads new size (number of pages per debug area) 1232 */ 1233 1234 static int 1235 debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 1236 struct file *file, const char __user *user_buf, 1237 size_t user_len, loff_t * offset) 1238 { 1239 char *str; 1240 int rc,new_pages; 1241 1242 if (user_len > 0x10000) 1243 user_len = 0x10000; 1244 if (*offset != 0){ 1245 rc = -EPIPE; 1246 goto out; 1247 } 1248 str = debug_get_user_string(user_buf,user_len); 1249 if(IS_ERR(str)){ 1250 rc = PTR_ERR(str); 1251 goto out; 1252 } 1253 new_pages = debug_get_uint(str); 1254 if(new_pages < 0){ 1255 rc = -EINVAL; 1256 goto free_str; 1257 } 1258 rc = debug_set_size(id,id->nr_areas, new_pages); 1259 if(rc != 0){ 1260 rc = -EINVAL; 1261 goto free_str; 1262 } 1263 rc = user_len; 1264 free_str: 1265 kfree(str); 1266 out: 1267 *offset += user_len; 1268 return rc; /* number of input characters */ 1269 } 1270 1271 /* 1272 * prints out actual debug level 1273 */ 1274 1275 static int 1276 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf) 1277 { 1278 int rc = 0; 1279 1280 if(id->level == DEBUG_OFF_LEVEL) { 1281 rc = sprintf(out_buf,"-\n"); 1282 } 1283 else { 1284 rc = sprintf(out_buf, "%i\n", id->level); 1285 } 1286 return rc; 1287 } 1288 1289 /* 1290 * reads new debug level 1291 */ 1292 1293 static int 1294 debug_input_level_fn(debug_info_t * id, struct debug_view *view, 1295 struct file *file, const char __user *user_buf, 1296 size_t user_len, loff_t * offset) 1297 { 1298 char *str; 1299 int rc,new_level; 1300 1301 if (user_len > 0x10000) 1302 user_len = 0x10000; 1303 if (*offset != 0){ 1304 rc = -EPIPE; 1305 goto out; 1306 } 1307 str = debug_get_user_string(user_buf,user_len); 1308 if(IS_ERR(str)){ 1309 rc = PTR_ERR(str); 1310 goto out; 1311 } 1312 if(str[0] == '-'){ 1313 debug_set_level(id, DEBUG_OFF_LEVEL); 1314 rc = user_len; 1315 goto free_str; 1316 } else { 1317 new_level = debug_get_uint(str); 1318 } 1319 if(new_level < 0) { 1320 pr_warning("%s is not a valid level for a debug " 1321 "feature\n", str); 1322 rc = -EINVAL; 1323 } else { 1324 debug_set_level(id, new_level); 1325 rc = user_len; 1326 } 1327 free_str: 1328 kfree(str); 1329 out: 1330 *offset += user_len; 1331 return rc; /* number of input characters */ 1332 } 1333 1334 1335 /* 1336 * flushes debug areas 1337 */ 1338 1339 static void debug_flush(debug_info_t* id, int area) 1340 { 1341 unsigned long flags; 1342 int i,j; 1343 1344 if(!id || !id->areas) 1345 return; 1346 spin_lock_irqsave(&id->lock,flags); 1347 if(area == DEBUG_FLUSH_ALL){ 1348 id->active_area = 0; 1349 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1350 for (i = 0; i < id->nr_areas; i++) { 1351 id->active_pages[i] = 0; 1352 for(j = 0; j < id->pages_per_area; j++) { 1353 memset(id->areas[i][j], 0, PAGE_SIZE); 1354 } 1355 } 1356 } else if(area >= 0 && area < id->nr_areas) { 1357 id->active_entries[area] = 0; 1358 id->active_pages[area] = 0; 1359 for(i = 0; i < id->pages_per_area; i++) { 1360 memset(id->areas[area][i],0,PAGE_SIZE); 1361 } 1362 } 1363 spin_unlock_irqrestore(&id->lock,flags); 1364 } 1365 1366 /* 1367 * view function: flushes debug areas 1368 */ 1369 1370 static int 1371 debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 1372 struct file *file, const char __user *user_buf, 1373 size_t user_len, loff_t * offset) 1374 { 1375 char input_buf[1]; 1376 int rc = user_len; 1377 1378 if (user_len > 0x10000) 1379 user_len = 0x10000; 1380 if (*offset != 0){ 1381 rc = -EPIPE; 1382 goto out; 1383 } 1384 if (copy_from_user(input_buf, user_buf, 1)){ 1385 rc = -EFAULT; 1386 goto out; 1387 } 1388 if(input_buf[0] == '-') { 1389 debug_flush(id, DEBUG_FLUSH_ALL); 1390 goto out; 1391 } 1392 if (isdigit(input_buf[0])) { 1393 int area = ((int) input_buf[0] - (int) '0'); 1394 debug_flush(id, area); 1395 goto out; 1396 } 1397 1398 pr_info("Flushing debug data failed because %c is not a valid " 1399 "area\n", input_buf[0]); 1400 1401 out: 1402 *offset += user_len; 1403 return rc; /* number of input characters */ 1404 } 1405 1406 /* 1407 * prints debug header in raw format 1408 */ 1409 1410 static int 1411 debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 1412 int area, debug_entry_t * entry, char *out_buf) 1413 { 1414 int rc; 1415 1416 rc = sizeof(debug_entry_t); 1417 memcpy(out_buf,entry,sizeof(debug_entry_t)); 1418 return rc; 1419 } 1420 1421 /* 1422 * prints debug data in raw format 1423 */ 1424 1425 static int 1426 debug_raw_format_fn(debug_info_t * id, struct debug_view *view, 1427 char *out_buf, const char *in_buf) 1428 { 1429 int rc; 1430 1431 rc = id->buf_size; 1432 memcpy(out_buf, in_buf, id->buf_size); 1433 return rc; 1434 } 1435 1436 /* 1437 * prints debug data in hex/ascii format 1438 */ 1439 1440 static int 1441 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 1442 char *out_buf, const char *in_buf) 1443 { 1444 int i, rc = 0; 1445 1446 for (i = 0; i < id->buf_size; i++) { 1447 rc += sprintf(out_buf + rc, "%02x ", 1448 ((unsigned char *) in_buf)[i]); 1449 } 1450 rc += sprintf(out_buf + rc, "| "); 1451 for (i = 0; i < id->buf_size; i++) { 1452 unsigned char c = in_buf[i]; 1453 if (isascii(c) && isprint(c)) 1454 rc += sprintf(out_buf + rc, "%c", c); 1455 else 1456 rc += sprintf(out_buf + rc, "."); 1457 } 1458 rc += sprintf(out_buf + rc, "\n"); 1459 return rc; 1460 } 1461 1462 /* 1463 * prints header for debug entry 1464 */ 1465 1466 int 1467 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view, 1468 int area, debug_entry_t * entry, char *out_buf) 1469 { 1470 struct timespec time_spec; 1471 char *except_str; 1472 unsigned long caller; 1473 int rc = 0; 1474 unsigned int level; 1475 1476 level = entry->id.fields.level; 1477 stck_to_timespec(entry->id.stck, &time_spec); 1478 1479 if (entry->id.fields.exception) 1480 except_str = "*"; 1481 else 1482 except_str = "-"; 1483 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN; 1484 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ", 1485 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level, 1486 except_str, entry->id.fields.cpuid, (void *) caller); 1487 return rc; 1488 } 1489 1490 /* 1491 * prints debug data sprintf-formated: 1492 * debug_sprinf_event/exception calls must be used together with this view 1493 */ 1494 1495 #define DEBUG_SPRINTF_MAX_ARGS 10 1496 1497 static int 1498 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 1499 char *out_buf, debug_sprintf_entry_t *curr_event) 1500 { 1501 int num_longs, num_used_args = 0,i, rc = 0; 1502 int index[DEBUG_SPRINTF_MAX_ARGS]; 1503 1504 /* count of longs fit into one entry */ 1505 num_longs = id->buf_size / sizeof(long); 1506 1507 if(num_longs < 1) 1508 goto out; /* bufsize of entry too small */ 1509 if(num_longs == 1) { 1510 /* no args, we use only the string */ 1511 strcpy(out_buf, curr_event->string); 1512 rc = strlen(curr_event->string); 1513 goto out; 1514 } 1515 1516 /* number of arguments used for sprintf (without the format string) */ 1517 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1518 1519 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1520 1521 for(i = 0; i < num_used_args; i++) 1522 index[i] = i; 1523 1524 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1525 curr_event->args[index[1]], curr_event->args[index[2]], 1526 curr_event->args[index[3]], curr_event->args[index[4]], 1527 curr_event->args[index[5]], curr_event->args[index[6]], 1528 curr_event->args[index[7]], curr_event->args[index[8]], 1529 curr_event->args[index[9]]); 1530 1531 out: 1532 1533 return rc; 1534 } 1535 1536 /* 1537 * clean up module 1538 */ 1539 static void __exit debug_exit(void) 1540 { 1541 debugfs_remove(debug_debugfs_root_entry); 1542 unregister_sysctl_table(s390dbf_sysctl_header); 1543 return; 1544 } 1545 1546 /* 1547 * module definitions 1548 */ 1549 postcore_initcall(debug_init); 1550 module_exit(debug_exit); 1551 MODULE_LICENSE("GPL"); 1552 1553 EXPORT_SYMBOL(debug_register); 1554 EXPORT_SYMBOL(debug_unregister); 1555 EXPORT_SYMBOL(debug_set_level); 1556 EXPORT_SYMBOL(debug_stop_all); 1557 EXPORT_SYMBOL(debug_register_view); 1558 EXPORT_SYMBOL(debug_unregister_view); 1559 EXPORT_SYMBOL(debug_event_common); 1560 EXPORT_SYMBOL(debug_exception_common); 1561 EXPORT_SYMBOL(debug_hex_ascii_view); 1562 EXPORT_SYMBOL(debug_raw_view); 1563 EXPORT_SYMBOL(debug_dflt_header_fn); 1564 EXPORT_SYMBOL(debug_sprintf_view); 1565 EXPORT_SYMBOL(debug_sprintf_exception); 1566 EXPORT_SYMBOL(debug_sprintf_event); 1567