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 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 atomic_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 debug_info_get(rc); 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 atomic_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 (atomic_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 active->id.fields.cpuid = smp_processor_id(); 871 active->caller = __builtin_return_address(0); 872 active->id.fields.exception = exception; 873 active->id.fields.level = level; 874 proceed_active_entry(id); 875 if(exception) 876 proceed_active_area(id); 877 } 878 879 static int debug_stoppable=1; 880 static int debug_active=1; 881 882 #define CTL_S390DBF_STOPPABLE 5678 883 #define CTL_S390DBF_ACTIVE 5679 884 885 /* 886 * proc handler for the running debug_active sysctl 887 * always allow read, allow write only if debug_stoppable is set or 888 * if debug_active is already off 889 */ 890 static int 891 s390dbf_procactive(struct ctl_table *table, int write, 892 void __user *buffer, size_t *lenp, loff_t *ppos) 893 { 894 if (!write || debug_stoppable || !debug_active) 895 return proc_dointvec(table, write, buffer, lenp, ppos); 896 else 897 return 0; 898 } 899 900 901 static struct ctl_table s390dbf_table[] = { 902 { 903 .procname = "debug_stoppable", 904 .data = &debug_stoppable, 905 .maxlen = sizeof(int), 906 .mode = S_IRUGO | S_IWUSR, 907 .proc_handler = proc_dointvec, 908 }, 909 { 910 .procname = "debug_active", 911 .data = &debug_active, 912 .maxlen = sizeof(int), 913 .mode = S_IRUGO | S_IWUSR, 914 .proc_handler = s390dbf_procactive, 915 }, 916 { } 917 }; 918 919 static struct ctl_table s390dbf_dir_table[] = { 920 { 921 .procname = "s390dbf", 922 .maxlen = 0, 923 .mode = S_IRUGO | S_IXUGO, 924 .child = s390dbf_table, 925 }, 926 { } 927 }; 928 929 static struct ctl_table_header *s390dbf_sysctl_header; 930 931 void 932 debug_stop_all(void) 933 { 934 if (debug_stoppable) 935 debug_active = 0; 936 } 937 EXPORT_SYMBOL(debug_stop_all); 938 939 void debug_set_critical(void) 940 { 941 debug_critical = 1; 942 } 943 944 /* 945 * debug_event_common: 946 * - write debug entry with given size 947 */ 948 949 debug_entry_t* 950 debug_event_common(debug_info_t * id, int level, const void *buf, int len) 951 { 952 unsigned long flags; 953 debug_entry_t *active; 954 955 if (!debug_active || !id->areas) 956 return NULL; 957 if (debug_critical) { 958 if (!spin_trylock_irqsave(&id->lock, flags)) 959 return NULL; 960 } else 961 spin_lock_irqsave(&id->lock, flags); 962 active = get_active_entry(id); 963 memset(DEBUG_DATA(active), 0, id->buf_size); 964 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 965 debug_finish_entry(id, active, level, 0); 966 spin_unlock_irqrestore(&id->lock, flags); 967 968 return active; 969 } 970 EXPORT_SYMBOL(debug_event_common); 971 972 /* 973 * debug_exception_common: 974 * - write debug entry with given size and switch to next debug area 975 */ 976 977 debug_entry_t 978 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len) 979 { 980 unsigned long flags; 981 debug_entry_t *active; 982 983 if (!debug_active || !id->areas) 984 return NULL; 985 if (debug_critical) { 986 if (!spin_trylock_irqsave(&id->lock, flags)) 987 return NULL; 988 } else 989 spin_lock_irqsave(&id->lock, flags); 990 active = get_active_entry(id); 991 memset(DEBUG_DATA(active), 0, id->buf_size); 992 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 993 debug_finish_entry(id, active, level, 1); 994 spin_unlock_irqrestore(&id->lock, flags); 995 996 return active; 997 } 998 EXPORT_SYMBOL(debug_exception_common); 999 1000 /* 1001 * counts arguments in format string for sprintf view 1002 */ 1003 1004 static inline int 1005 debug_count_numargs(char *string) 1006 { 1007 int numargs=0; 1008 1009 while(*string) { 1010 if(*string++=='%') 1011 numargs++; 1012 } 1013 return(numargs); 1014 } 1015 1016 /* 1017 * debug_sprintf_event: 1018 */ 1019 1020 debug_entry_t* 1021 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 1022 { 1023 va_list ap; 1024 int numargs,idx; 1025 unsigned long flags; 1026 debug_sprintf_entry_t *curr_event; 1027 debug_entry_t *active; 1028 1029 if (!debug_active || !id->areas) 1030 return NULL; 1031 numargs=debug_count_numargs(string); 1032 1033 if (debug_critical) { 1034 if (!spin_trylock_irqsave(&id->lock, flags)) 1035 return NULL; 1036 } else 1037 spin_lock_irqsave(&id->lock, flags); 1038 active = get_active_entry(id); 1039 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active); 1040 va_start(ap,string); 1041 curr_event->string=string; 1042 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1043 curr_event->args[idx]=va_arg(ap,long); 1044 va_end(ap); 1045 debug_finish_entry(id, active, level, 0); 1046 spin_unlock_irqrestore(&id->lock, flags); 1047 1048 return active; 1049 } 1050 EXPORT_SYMBOL(__debug_sprintf_event); 1051 1052 /* 1053 * debug_sprintf_exception: 1054 */ 1055 1056 debug_entry_t* 1057 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 1058 { 1059 va_list ap; 1060 int numargs,idx; 1061 unsigned long flags; 1062 debug_sprintf_entry_t *curr_event; 1063 debug_entry_t *active; 1064 1065 if (!debug_active || !id->areas) 1066 return NULL; 1067 1068 numargs=debug_count_numargs(string); 1069 1070 if (debug_critical) { 1071 if (!spin_trylock_irqsave(&id->lock, flags)) 1072 return NULL; 1073 } else 1074 spin_lock_irqsave(&id->lock, flags); 1075 active = get_active_entry(id); 1076 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active); 1077 va_start(ap,string); 1078 curr_event->string=string; 1079 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1080 curr_event->args[idx]=va_arg(ap,long); 1081 va_end(ap); 1082 debug_finish_entry(id, active, level, 1); 1083 spin_unlock_irqrestore(&id->lock, flags); 1084 1085 return active; 1086 } 1087 EXPORT_SYMBOL(__debug_sprintf_exception); 1088 1089 /* 1090 * debug_register_view: 1091 */ 1092 1093 int 1094 debug_register_view(debug_info_t * id, struct debug_view *view) 1095 { 1096 int rc = 0; 1097 int i; 1098 unsigned long flags; 1099 umode_t mode; 1100 struct dentry *pde; 1101 1102 if (!id) 1103 goto out; 1104 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1105 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1106 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1107 if (!view->input_proc) 1108 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1109 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1110 id , &debug_file_ops); 1111 if (!pde){ 1112 pr_err("Registering view %s/%s failed due to out of " 1113 "memory\n", id->name,view->name); 1114 rc = -1; 1115 goto out; 1116 } 1117 spin_lock_irqsave(&id->lock, flags); 1118 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1119 if (!id->views[i]) 1120 break; 1121 } 1122 if (i == DEBUG_MAX_VIEWS) { 1123 pr_err("Registering view %s/%s would exceed the maximum " 1124 "number of views %i\n", id->name, view->name, i); 1125 rc = -1; 1126 } else { 1127 id->views[i] = view; 1128 id->debugfs_entries[i] = pde; 1129 } 1130 spin_unlock_irqrestore(&id->lock, flags); 1131 if (rc) 1132 debugfs_remove(pde); 1133 out: 1134 return rc; 1135 } 1136 EXPORT_SYMBOL(debug_register_view); 1137 1138 /* 1139 * debug_unregister_view: 1140 */ 1141 1142 int 1143 debug_unregister_view(debug_info_t * id, struct debug_view *view) 1144 { 1145 struct dentry *dentry = NULL; 1146 unsigned long flags; 1147 int i, rc = 0; 1148 1149 if (!id) 1150 goto out; 1151 spin_lock_irqsave(&id->lock, flags); 1152 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1153 if (id->views[i] == view) 1154 break; 1155 } 1156 if (i == DEBUG_MAX_VIEWS) 1157 rc = -1; 1158 else { 1159 dentry = id->debugfs_entries[i]; 1160 id->views[i] = NULL; 1161 id->debugfs_entries[i] = NULL; 1162 } 1163 spin_unlock_irqrestore(&id->lock, flags); 1164 debugfs_remove(dentry); 1165 out: 1166 return rc; 1167 } 1168 EXPORT_SYMBOL(debug_unregister_view); 1169 1170 static inline char * 1171 debug_get_user_string(const char __user *user_buf, size_t user_len) 1172 { 1173 char* buffer; 1174 1175 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1176 if (!buffer) 1177 return ERR_PTR(-ENOMEM); 1178 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1179 kfree(buffer); 1180 return ERR_PTR(-EFAULT); 1181 } 1182 /* got the string, now strip linefeed. */ 1183 if (buffer[user_len - 1] == '\n') 1184 buffer[user_len - 1] = 0; 1185 else 1186 buffer[user_len] = 0; 1187 return buffer; 1188 } 1189 1190 static inline int 1191 debug_get_uint(char *buf) 1192 { 1193 int rc; 1194 1195 buf = skip_spaces(buf); 1196 rc = simple_strtoul(buf, &buf, 10); 1197 if(*buf){ 1198 rc = -EINVAL; 1199 } 1200 return rc; 1201 } 1202 1203 /* 1204 * functions for debug-views 1205 *********************************** 1206 */ 1207 1208 /* 1209 * prints out actual debug level 1210 */ 1211 1212 static int 1213 debug_prolog_pages_fn(debug_info_t * id, 1214 struct debug_view *view, char *out_buf) 1215 { 1216 return sprintf(out_buf, "%i\n", id->pages_per_area); 1217 } 1218 1219 /* 1220 * reads new size (number of pages per debug area) 1221 */ 1222 1223 static int 1224 debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 1225 struct file *file, const char __user *user_buf, 1226 size_t user_len, loff_t * offset) 1227 { 1228 char *str; 1229 int rc,new_pages; 1230 1231 if (user_len > 0x10000) 1232 user_len = 0x10000; 1233 if (*offset != 0){ 1234 rc = -EPIPE; 1235 goto out; 1236 } 1237 str = debug_get_user_string(user_buf,user_len); 1238 if(IS_ERR(str)){ 1239 rc = PTR_ERR(str); 1240 goto out; 1241 } 1242 new_pages = debug_get_uint(str); 1243 if(new_pages < 0){ 1244 rc = -EINVAL; 1245 goto free_str; 1246 } 1247 rc = debug_set_size(id,id->nr_areas, new_pages); 1248 if(rc != 0){ 1249 rc = -EINVAL; 1250 goto free_str; 1251 } 1252 rc = user_len; 1253 free_str: 1254 kfree(str); 1255 out: 1256 *offset += user_len; 1257 return rc; /* number of input characters */ 1258 } 1259 1260 /* 1261 * prints out actual debug level 1262 */ 1263 1264 static int 1265 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf) 1266 { 1267 int rc = 0; 1268 1269 if(id->level == DEBUG_OFF_LEVEL) { 1270 rc = sprintf(out_buf,"-\n"); 1271 } 1272 else { 1273 rc = sprintf(out_buf, "%i\n", id->level); 1274 } 1275 return rc; 1276 } 1277 1278 /* 1279 * reads new debug level 1280 */ 1281 1282 static int 1283 debug_input_level_fn(debug_info_t * id, struct debug_view *view, 1284 struct file *file, const char __user *user_buf, 1285 size_t user_len, loff_t * offset) 1286 { 1287 char *str; 1288 int rc,new_level; 1289 1290 if (user_len > 0x10000) 1291 user_len = 0x10000; 1292 if (*offset != 0){ 1293 rc = -EPIPE; 1294 goto out; 1295 } 1296 str = debug_get_user_string(user_buf,user_len); 1297 if(IS_ERR(str)){ 1298 rc = PTR_ERR(str); 1299 goto out; 1300 } 1301 if(str[0] == '-'){ 1302 debug_set_level(id, DEBUG_OFF_LEVEL); 1303 rc = user_len; 1304 goto free_str; 1305 } else { 1306 new_level = debug_get_uint(str); 1307 } 1308 if(new_level < 0) { 1309 pr_warn("%s is not a valid level for a debug feature\n", str); 1310 rc = -EINVAL; 1311 } else { 1312 debug_set_level(id, new_level); 1313 rc = user_len; 1314 } 1315 free_str: 1316 kfree(str); 1317 out: 1318 *offset += user_len; 1319 return rc; /* number of input characters */ 1320 } 1321 1322 1323 /* 1324 * flushes debug areas 1325 */ 1326 1327 static void debug_flush(debug_info_t* id, int area) 1328 { 1329 unsigned long flags; 1330 int i,j; 1331 1332 if(!id || !id->areas) 1333 return; 1334 spin_lock_irqsave(&id->lock,flags); 1335 if(area == DEBUG_FLUSH_ALL){ 1336 id->active_area = 0; 1337 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1338 for (i = 0; i < id->nr_areas; i++) { 1339 id->active_pages[i] = 0; 1340 for(j = 0; j < id->pages_per_area; j++) { 1341 memset(id->areas[i][j], 0, PAGE_SIZE); 1342 } 1343 } 1344 } else if(area >= 0 && area < id->nr_areas) { 1345 id->active_entries[area] = 0; 1346 id->active_pages[area] = 0; 1347 for(i = 0; i < id->pages_per_area; i++) { 1348 memset(id->areas[area][i],0,PAGE_SIZE); 1349 } 1350 } 1351 spin_unlock_irqrestore(&id->lock,flags); 1352 } 1353 1354 /* 1355 * view function: flushes debug areas 1356 */ 1357 1358 static int 1359 debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 1360 struct file *file, const char __user *user_buf, 1361 size_t user_len, loff_t * offset) 1362 { 1363 char input_buf[1]; 1364 int rc = user_len; 1365 1366 if (user_len > 0x10000) 1367 user_len = 0x10000; 1368 if (*offset != 0){ 1369 rc = -EPIPE; 1370 goto out; 1371 } 1372 if (copy_from_user(input_buf, user_buf, 1)){ 1373 rc = -EFAULT; 1374 goto out; 1375 } 1376 if(input_buf[0] == '-') { 1377 debug_flush(id, DEBUG_FLUSH_ALL); 1378 goto out; 1379 } 1380 if (isdigit(input_buf[0])) { 1381 int area = ((int) input_buf[0] - (int) '0'); 1382 debug_flush(id, area); 1383 goto out; 1384 } 1385 1386 pr_info("Flushing debug data failed because %c is not a valid " 1387 "area\n", input_buf[0]); 1388 1389 out: 1390 *offset += user_len; 1391 return rc; /* number of input characters */ 1392 } 1393 1394 /* 1395 * prints debug header in raw format 1396 */ 1397 1398 static int 1399 debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 1400 int area, debug_entry_t * entry, char *out_buf) 1401 { 1402 int rc; 1403 1404 rc = sizeof(debug_entry_t); 1405 memcpy(out_buf,entry,sizeof(debug_entry_t)); 1406 return rc; 1407 } 1408 1409 /* 1410 * prints debug data in raw format 1411 */ 1412 1413 static int 1414 debug_raw_format_fn(debug_info_t * id, struct debug_view *view, 1415 char *out_buf, const char *in_buf) 1416 { 1417 int rc; 1418 1419 rc = id->buf_size; 1420 memcpy(out_buf, in_buf, id->buf_size); 1421 return rc; 1422 } 1423 1424 /* 1425 * prints debug data in hex/ascii format 1426 */ 1427 1428 static int 1429 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 1430 char *out_buf, const char *in_buf) 1431 { 1432 int i, rc = 0; 1433 1434 for (i = 0; i < id->buf_size; i++) { 1435 rc += sprintf(out_buf + rc, "%02x ", 1436 ((unsigned char *) in_buf)[i]); 1437 } 1438 rc += sprintf(out_buf + rc, "| "); 1439 for (i = 0; i < id->buf_size; i++) { 1440 unsigned char c = in_buf[i]; 1441 if (isascii(c) && isprint(c)) 1442 rc += sprintf(out_buf + rc, "%c", c); 1443 else 1444 rc += sprintf(out_buf + rc, "."); 1445 } 1446 rc += sprintf(out_buf + rc, "\n"); 1447 return rc; 1448 } 1449 1450 /* 1451 * prints header for debug entry 1452 */ 1453 1454 int 1455 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view, 1456 int area, debug_entry_t * entry, char *out_buf) 1457 { 1458 struct timespec64 time_spec; 1459 char *except_str; 1460 unsigned long caller; 1461 int rc = 0; 1462 unsigned int level; 1463 1464 level = entry->id.fields.level; 1465 stck_to_timespec64(entry->id.stck, &time_spec); 1466 1467 if (entry->id.fields.exception) 1468 except_str = "*"; 1469 else 1470 except_str = "-"; 1471 caller = (unsigned long) entry->caller; 1472 rc += sprintf(out_buf, "%02i %011lld:%06lu %1u %1s %02i %p ", 1473 area, (long long)time_spec.tv_sec, 1474 time_spec.tv_nsec / 1000, level, except_str, 1475 entry->id.fields.cpuid, (void *)caller); 1476 return rc; 1477 } 1478 EXPORT_SYMBOL(debug_dflt_header_fn); 1479 1480 /* 1481 * prints debug data sprintf-formated: 1482 * debug_sprinf_event/exception calls must be used together with this view 1483 */ 1484 1485 #define DEBUG_SPRINTF_MAX_ARGS 10 1486 1487 static int 1488 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 1489 char *out_buf, debug_sprintf_entry_t *curr_event) 1490 { 1491 int num_longs, num_used_args = 0,i, rc = 0; 1492 int index[DEBUG_SPRINTF_MAX_ARGS]; 1493 1494 /* count of longs fit into one entry */ 1495 num_longs = id->buf_size / sizeof(long); 1496 1497 if(num_longs < 1) 1498 goto out; /* bufsize of entry too small */ 1499 if(num_longs == 1) { 1500 /* no args, we use only the string */ 1501 strcpy(out_buf, curr_event->string); 1502 rc = strlen(curr_event->string); 1503 goto out; 1504 } 1505 1506 /* number of arguments used for sprintf (without the format string) */ 1507 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1508 1509 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1510 1511 for(i = 0; i < num_used_args; i++) 1512 index[i] = i; 1513 1514 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1515 curr_event->args[index[1]], curr_event->args[index[2]], 1516 curr_event->args[index[3]], curr_event->args[index[4]], 1517 curr_event->args[index[5]], curr_event->args[index[6]], 1518 curr_event->args[index[7]], curr_event->args[index[8]], 1519 curr_event->args[index[9]]); 1520 1521 out: 1522 1523 return rc; 1524 } 1525 1526 /* 1527 * debug_init: 1528 * - is called exactly once to initialize the debug feature 1529 */ 1530 static int __init debug_init(void) 1531 { 1532 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1533 mutex_lock(&debug_mutex); 1534 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1535 initialized = 1; 1536 mutex_unlock(&debug_mutex); 1537 return 0; 1538 } 1539 postcore_initcall(debug_init); 1540