1/* 2 * arch/s390/kernel/debug.c 3 * S/390 debug facility 4 * 5 * Copyright (C) 1999, 2000 IBM Deutschland Entwicklung GmbH, 6 * IBM Corporation 7 * Author(s): Michael Holzheu (holzheu@de.ibm.com), 8 * Holger Smolinski (Holger.Smolinski@de.ibm.com) 9 * 10 * Bugreports to: <Linux390@de.ibm.com> 11 */ 12 13#define KMSG_COMPONENT "s390dbf" 14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 15 16#include <linux/stddef.h> 17#include <linux/kernel.h> 18#include <linux/errno.h> 19#include <linux/slab.h> 20#include <linux/ctype.h> 21#include <linux/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 38typedef 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 54typedef 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 69static int debug_init(void); 70static ssize_t debug_output(struct file *file, char __user *user_buf, 71 size_t user_len, loff_t * offset); 72static ssize_t debug_input(struct file *file, const char __user *user_buf, 73 size_t user_len, loff_t * offset); 74static int debug_open(struct inode *inode, struct file *file); 75static int debug_close(struct inode *inode, struct file *file); 76static debug_info_t *debug_info_create(const char *name, int pages_per_area, 77 int nr_areas, int buf_size, mode_t mode); 78static void debug_info_get(debug_info_t *); 79static void debug_info_put(debug_info_t *); 80static int debug_prolog_level_fn(debug_info_t * id, 81 struct debug_view *view, char *out_buf); 82static 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); 85static int debug_prolog_pages_fn(debug_info_t * id, 86 struct debug_view *view, char *out_buf); 87static 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); 90static 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); 93static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 94 char *out_buf, const char *in_buf); 95static int debug_raw_format_fn(debug_info_t * id, 96 struct debug_view *view, char *out_buf, 97 const char *in_buf); 98static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 99 int area, debug_entry_t * entry, char *out_buf); 100 101static 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 106struct 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 115struct 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 124static 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 133static 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 142static struct debug_view debug_flush_view = { 143 "flush", 144 NULL, 145 NULL, 146 NULL, 147 &debug_input_flush_fn, 148 NULL 149}; 150 151struct 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 */ 161static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 162 163/* static globals */ 164 165static debug_info_t *debug_area_first = NULL; 166static debug_info_t *debug_area_last = NULL; 167static DEFINE_MUTEX(debug_mutex); 168 169static int initialized; 170 171static 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}; 178 179static struct dentry *debug_debugfs_root_entry; 180 181/* functions */ 182 183/* 184 * debug_areas_alloc 185 * - Debug areas are implemented as a threedimensonal array: 186 * areas[areanumber][pagenumber][pageoffset] 187 */ 188 189static debug_entry_t*** 190debug_areas_alloc(int pages_per_area, int nr_areas) 191{ 192 debug_entry_t*** areas; 193 int i,j; 194 195 areas = kmalloc(nr_areas * 196 sizeof(debug_entry_t**), 197 GFP_KERNEL); 198 if (!areas) 199 goto fail_malloc_areas; 200 for (i = 0; i < nr_areas; i++) { 201 areas[i] = kmalloc(pages_per_area * 202 sizeof(debug_entry_t*),GFP_KERNEL); 203 if (!areas[i]) { 204 goto fail_malloc_areas2; 205 } 206 for(j = 0; j < pages_per_area; j++) { 207 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); 208 if(!areas[i][j]) { 209 for(j--; j >=0 ; j--) { 210 kfree(areas[i][j]); 211 } 212 kfree(areas[i]); 213 goto fail_malloc_areas2; 214 } 215 } 216 } 217 return areas; 218 219fail_malloc_areas2: 220 for(i--; i >= 0; i--){ 221 for(j=0; j < pages_per_area;j++){ 222 kfree(areas[i][j]); 223 } 224 kfree(areas[i]); 225 } 226 kfree(areas); 227fail_malloc_areas: 228 return NULL; 229 230} 231 232 233/* 234 * debug_info_alloc 235 * - alloc new debug-info 236 */ 237 238static debug_info_t* 239debug_info_alloc(const char *name, int pages_per_area, int nr_areas, 240 int buf_size, int level, int mode) 241{ 242 debug_info_t* rc; 243 244 /* alloc everything */ 245 246 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); 247 if(!rc) 248 goto fail_malloc_rc; 249 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 250 if(!rc->active_entries) 251 goto fail_malloc_active_entries; 252 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 253 if(!rc->active_pages) 254 goto fail_malloc_active_pages; 255 if((mode == ALL_AREAS) && (pages_per_area != 0)){ 256 rc->areas = debug_areas_alloc(pages_per_area, nr_areas); 257 if(!rc->areas) 258 goto fail_malloc_areas; 259 } else { 260 rc->areas = NULL; 261 } 262 263 /* initialize members */ 264 265 spin_lock_init(&rc->lock); 266 rc->pages_per_area = pages_per_area; 267 rc->nr_areas = nr_areas; 268 rc->active_area = 0; 269 rc->level = level; 270 rc->buf_size = buf_size; 271 rc->entry_size = sizeof(debug_entry_t) + buf_size; 272 strlcpy(rc->name, name, sizeof(rc->name)); 273 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); 274 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS * 275 sizeof(struct dentry*)); 276 atomic_set(&(rc->ref_count), 0); 277 278 return rc; 279 280fail_malloc_areas: 281 kfree(rc->active_pages); 282fail_malloc_active_pages: 283 kfree(rc->active_entries); 284fail_malloc_active_entries: 285 kfree(rc); 286fail_malloc_rc: 287 return NULL; 288} 289 290/* 291 * debug_areas_free 292 * - free all debug areas 293 */ 294 295static void 296debug_areas_free(debug_info_t* db_info) 297{ 298 int i,j; 299 300 if(!db_info->areas) 301 return; 302 for (i = 0; i < db_info->nr_areas; i++) { 303 for(j = 0; j < db_info->pages_per_area; j++) { 304 kfree(db_info->areas[i][j]); 305 } 306 kfree(db_info->areas[i]); 307 } 308 kfree(db_info->areas); 309 db_info->areas = NULL; 310} 311 312/* 313 * debug_info_free 314 * - free memory debug-info 315 */ 316 317static void 318debug_info_free(debug_info_t* db_info){ 319 debug_areas_free(db_info); 320 kfree(db_info->active_entries); 321 kfree(db_info->active_pages); 322 kfree(db_info); 323} 324 325/* 326 * debug_info_create 327 * - create new debug-info 328 */ 329 330static debug_info_t* 331debug_info_create(const char *name, int pages_per_area, int nr_areas, 332 int buf_size, mode_t mode) 333{ 334 debug_info_t* rc; 335 336 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, 337 DEBUG_DEFAULT_LEVEL, ALL_AREAS); 338 if(!rc) 339 goto out; 340 341 rc->mode = mode & ~S_IFMT; 342 343 /* create root directory */ 344 rc->debugfs_root_entry = debugfs_create_dir(rc->name, 345 debug_debugfs_root_entry); 346 347 /* append new element to linked list */ 348 if (!debug_area_first) { 349 /* first element in list */ 350 debug_area_first = rc; 351 rc->prev = NULL; 352 } else { 353 /* append element to end of list */ 354 debug_area_last->next = rc; 355 rc->prev = debug_area_last; 356 } 357 debug_area_last = rc; 358 rc->next = NULL; 359 360 debug_info_get(rc); 361out: 362 return rc; 363} 364 365/* 366 * debug_info_copy 367 * - copy debug-info 368 */ 369 370static debug_info_t* 371debug_info_copy(debug_info_t* in, int mode) 372{ 373 int i,j; 374 debug_info_t* rc; 375 unsigned long flags; 376 377 /* get a consistent copy of the debug areas */ 378 do { 379 rc = debug_info_alloc(in->name, in->pages_per_area, 380 in->nr_areas, in->buf_size, in->level, mode); 381 spin_lock_irqsave(&in->lock, flags); 382 if(!rc) 383 goto out; 384 /* has something changed in the meantime ? */ 385 if((rc->pages_per_area == in->pages_per_area) && 386 (rc->nr_areas == in->nr_areas)) { 387 break; 388 } 389 spin_unlock_irqrestore(&in->lock, flags); 390 debug_info_free(rc); 391 } while (1); 392 393 if (mode == NO_AREAS) 394 goto out; 395 396 for(i = 0; i < in->nr_areas; i++){ 397 for(j = 0; j < in->pages_per_area; j++) { 398 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE); 399 } 400 } 401out: 402 spin_unlock_irqrestore(&in->lock, flags); 403 return rc; 404} 405 406/* 407 * debug_info_get 408 * - increments reference count for debug-info 409 */ 410 411static void 412debug_info_get(debug_info_t * db_info) 413{ 414 if (db_info) 415 atomic_inc(&db_info->ref_count); 416} 417 418/* 419 * debug_info_put: 420 * - decreases reference count for debug-info and frees it if necessary 421 */ 422 423static void 424debug_info_put(debug_info_t *db_info) 425{ 426 int i; 427 428 if (!db_info) 429 return; 430 if (atomic_dec_and_test(&db_info->ref_count)) { 431 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 432 if (!db_info->views[i]) 433 continue; 434 debugfs_remove(db_info->debugfs_entries[i]); 435 } 436 debugfs_remove(db_info->debugfs_root_entry); 437 if(db_info == debug_area_first) 438 debug_area_first = db_info->next; 439 if(db_info == debug_area_last) 440 debug_area_last = db_info->prev; 441 if(db_info->prev) db_info->prev->next = db_info->next; 442 if(db_info->next) db_info->next->prev = db_info->prev; 443 debug_info_free(db_info); 444 } 445} 446 447/* 448 * debug_format_entry: 449 * - format one debug entry and return size of formated data 450 */ 451 452static int 453debug_format_entry(file_private_info_t *p_info) 454{ 455 debug_info_t *id_snap = p_info->debug_info_snap; 456 struct debug_view *view = p_info->view; 457 debug_entry_t *act_entry; 458 size_t len = 0; 459 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 460 /* print prolog */ 461 if (view->prolog_proc) 462 len += view->prolog_proc(id_snap,view,p_info->temp_buf); 463 goto out; 464 } 465 if (!id_snap->areas) /* this is true, if we have a prolog only view */ 466 goto out; /* or if 'pages_per_area' is 0 */ 467 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area] 468 [p_info->act_page] + p_info->act_entry); 469 470 if (act_entry->id.stck == 0LL) 471 goto out; /* empty entry */ 472 if (view->header_proc) 473 len += view->header_proc(id_snap, view, p_info->act_area, 474 act_entry, p_info->temp_buf + len); 475 if (view->format_proc) 476 len += view->format_proc(id_snap, view, p_info->temp_buf + len, 477 DEBUG_DATA(act_entry)); 478out: 479 return len; 480} 481 482/* 483 * debug_next_entry: 484 * - goto next entry in p_info 485 */ 486 487static inline int 488debug_next_entry(file_private_info_t *p_info) 489{ 490 debug_info_t *id; 491 492 id = p_info->debug_info_snap; 493 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){ 494 p_info->act_entry = 0; 495 p_info->act_page = 0; 496 goto out; 497 } 498 if(!id->areas) 499 return 1; 500 p_info->act_entry += id->entry_size; 501 /* switch to next page, if we reached the end of the page */ 502 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){ 503 /* next page */ 504 p_info->act_entry = 0; 505 p_info->act_page += 1; 506 if((p_info->act_page % id->pages_per_area) == 0) { 507 /* next area */ 508 p_info->act_area++; 509 p_info->act_page=0; 510 } 511 if(p_info->act_area >= id->nr_areas) 512 return 1; 513 } 514out: 515 return 0; 516} 517 518/* 519 * debug_output: 520 * - called for user read() 521 * - copies formated debug entries to the user buffer 522 */ 523 524static ssize_t 525debug_output(struct file *file, /* file descriptor */ 526 char __user *user_buf, /* user buffer */ 527 size_t len, /* length of buffer */ 528 loff_t *offset) /* offset in the file */ 529{ 530 size_t count = 0; 531 size_t entry_offset; 532 file_private_info_t *p_info; 533 534 p_info = ((file_private_info_t *) file->private_data); 535 if (*offset != p_info->offset) 536 return -EPIPE; 537 if(p_info->act_area >= p_info->debug_info_snap->nr_areas) 538 return 0; 539 entry_offset = p_info->act_entry_offset; 540 while(count < len){ 541 int formatted_line_size; 542 int formatted_line_residue; 543 int user_buf_residue; 544 size_t copy_size; 545 546 formatted_line_size = debug_format_entry(p_info); 547 formatted_line_residue = formatted_line_size - entry_offset; 548 user_buf_residue = len-count; 549 copy_size = min(user_buf_residue, formatted_line_residue); 550 if(copy_size){ 551 if (copy_to_user(user_buf + count, p_info->temp_buf 552 + entry_offset, copy_size)) 553 return -EFAULT; 554 count += copy_size; 555 entry_offset += copy_size; 556 } 557 if(copy_size == formatted_line_residue){ 558 entry_offset = 0; 559 if(debug_next_entry(p_info)) 560 goto out; 561 } 562 } 563out: 564 p_info->offset = *offset + count; 565 p_info->act_entry_offset = entry_offset; 566 *offset = p_info->offset; 567 return count; 568} 569 570/* 571 * debug_input: 572 * - called for user write() 573 * - calls input function of view 574 */ 575 576static ssize_t 577debug_input(struct file *file, const char __user *user_buf, size_t length, 578 loff_t *offset) 579{ 580 int rc = 0; 581 file_private_info_t *p_info; 582 583 mutex_lock(&debug_mutex); 584 p_info = ((file_private_info_t *) file->private_data); 585 if (p_info->view->input_proc) 586 rc = p_info->view->input_proc(p_info->debug_info_org, 587 p_info->view, file, user_buf, 588 length, offset); 589 else 590 rc = -EPERM; 591 mutex_unlock(&debug_mutex); 592 return rc; /* number of input characters */ 593} 594 595/* 596 * debug_open: 597 * - called for user open() 598 * - copies formated output to private_data area of the file 599 * handle 600 */ 601 602static int 603debug_open(struct inode *inode, struct file *file) 604{ 605 int i, rc = 0; 606 file_private_info_t *p_info; 607 debug_info_t *debug_info, *debug_info_snapshot; 608 609 mutex_lock(&debug_mutex); 610 debug_info = file->f_path.dentry->d_inode->i_private; 611 /* find debug view */ 612 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 613 if (!debug_info->views[i]) 614 continue; 615 else if (debug_info->debugfs_entries[i] == 616 file->f_path.dentry) { 617 goto found; /* found view ! */ 618 } 619 } 620 /* no entry found */ 621 rc = -EINVAL; 622 goto out; 623 624found: 625 626 /* Make snapshot of current debug areas to get it consistent. */ 627 /* To copy all the areas is only needed, if we have a view which */ 628 /* formats the debug areas. */ 629 630 if(!debug_info->views[i]->format_proc && 631 !debug_info->views[i]->header_proc){ 632 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS); 633 } else { 634 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS); 635 } 636 637 if(!debug_info_snapshot){ 638 rc = -ENOMEM; 639 goto out; 640 } 641 p_info = kmalloc(sizeof(file_private_info_t), 642 GFP_KERNEL); 643 if(!p_info){ 644 debug_info_free(debug_info_snapshot); 645 rc = -ENOMEM; 646 goto out; 647 } 648 p_info->offset = 0; 649 p_info->debug_info_snap = debug_info_snapshot; 650 p_info->debug_info_org = debug_info; 651 p_info->view = debug_info->views[i]; 652 p_info->act_area = 0; 653 p_info->act_page = 0; 654 p_info->act_entry = DEBUG_PROLOG_ENTRY; 655 p_info->act_entry_offset = 0; 656 file->private_data = p_info; 657 debug_info_get(debug_info); 658 nonseekable_open(inode, file); 659out: 660 mutex_unlock(&debug_mutex); 661 return rc; 662} 663 664/* 665 * debug_close: 666 * - called for user close() 667 * - deletes private_data area of the file handle 668 */ 669 670static int 671debug_close(struct inode *inode, struct file *file) 672{ 673 file_private_info_t *p_info; 674 p_info = (file_private_info_t *) file->private_data; 675 if(p_info->debug_info_snap) 676 debug_info_free(p_info->debug_info_snap); 677 debug_info_put(p_info->debug_info_org); 678 kfree(file->private_data); 679 return 0; /* success */ 680} 681 682/* 683 * debug_register_mode: 684 * - Creates and initializes debug area for the caller 685 * The mode parameter allows to specify access rights for the s390dbf files 686 * - Returns handle for debug area 687 */ 688 689debug_info_t *debug_register_mode(const char *name, int pages_per_area, 690 int nr_areas, int buf_size, mode_t mode, 691 uid_t uid, gid_t gid) 692{ 693 debug_info_t *rc = NULL; 694 695 /* Since debugfs currently does not support uid/gid other than root, */ 696 /* we do not allow gid/uid != 0 until we get support for that. */ 697 if ((uid != 0) || (gid != 0)) 698 pr_warning("Root becomes the owner of all s390dbf files " 699 "in sysfs\n"); 700 BUG_ON(!initialized); 701 mutex_lock(&debug_mutex); 702 703 /* create new debug_info */ 704 705 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 706 if(!rc) 707 goto out; 708 debug_register_view(rc, &debug_level_view); 709 debug_register_view(rc, &debug_flush_view); 710 debug_register_view(rc, &debug_pages_view); 711out: 712 if (!rc){ 713 pr_err("Registering debug feature %s failed\n", name); 714 } 715 mutex_unlock(&debug_mutex); 716 return rc; 717} 718EXPORT_SYMBOL(debug_register_mode); 719 720/* 721 * debug_register: 722 * - creates and initializes debug area for the caller 723 * - returns handle for debug area 724 */ 725 726debug_info_t *debug_register(const char *name, int pages_per_area, 727 int nr_areas, int buf_size) 728{ 729 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 730 S_IRUSR | S_IWUSR, 0, 0); 731} 732 733/* 734 * debug_unregister: 735 * - give back debug area 736 */ 737 738void 739debug_unregister(debug_info_t * id) 740{ 741 if (!id) 742 goto out; 743 mutex_lock(&debug_mutex); 744 debug_info_put(id); 745 mutex_unlock(&debug_mutex); 746 747out: 748 return; 749} 750 751/* 752 * debug_set_size: 753 * - set area size (number of pages) and number of areas 754 */ 755static int 756debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area) 757{ 758 unsigned long flags; 759 debug_entry_t *** new_areas; 760 int rc=0; 761 762 if(!id || (nr_areas <= 0) || (pages_per_area < 0)) 763 return -EINVAL; 764 if(pages_per_area > 0){ 765 new_areas = debug_areas_alloc(pages_per_area, nr_areas); 766 if(!new_areas) { 767 pr_info("Allocating memory for %i pages failed\n", 768 pages_per_area); 769 rc = -ENOMEM; 770 goto out; 771 } 772 } else { 773 new_areas = NULL; 774 } 775 spin_lock_irqsave(&id->lock,flags); 776 debug_areas_free(id); 777 id->areas = new_areas; 778 id->nr_areas = nr_areas; 779 id->pages_per_area = pages_per_area; 780 id->active_area = 0; 781 memset(id->active_entries,0,sizeof(int)*id->nr_areas); 782 memset(id->active_pages, 0, sizeof(int)*id->nr_areas); 783 spin_unlock_irqrestore(&id->lock,flags); 784 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area); 785out: 786 return rc; 787} 788 789/* 790 * debug_set_level: 791 * - set actual debug level 792 */ 793 794void 795debug_set_level(debug_info_t* id, int new_level) 796{ 797 unsigned long flags; 798 if(!id) 799 return; 800 spin_lock_irqsave(&id->lock,flags); 801 if(new_level == DEBUG_OFF_LEVEL){ 802 id->level = DEBUG_OFF_LEVEL; 803 pr_info("%s: switched off\n",id->name); 804 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 805 pr_info("%s: level %i is out of range (%i - %i)\n", 806 id->name, new_level, 0, DEBUG_MAX_LEVEL); 807 } else { 808 id->level = new_level; 809 } 810 spin_unlock_irqrestore(&id->lock,flags); 811} 812 813 814/* 815 * proceed_active_entry: 816 * - set active entry to next in the ring buffer 817 */ 818 819static inline void 820proceed_active_entry(debug_info_t * id) 821{ 822 if ((id->active_entries[id->active_area] += id->entry_size) 823 > (PAGE_SIZE - id->entry_size)){ 824 id->active_entries[id->active_area] = 0; 825 id->active_pages[id->active_area] = 826 (id->active_pages[id->active_area] + 1) % 827 id->pages_per_area; 828 } 829} 830 831/* 832 * proceed_active_area: 833 * - set active area to next in the ring buffer 834 */ 835 836static inline void 837proceed_active_area(debug_info_t * id) 838{ 839 id->active_area++; 840 id->active_area = id->active_area % id->nr_areas; 841} 842 843/* 844 * get_active_entry: 845 */ 846 847static inline debug_entry_t* 848get_active_entry(debug_info_t * id) 849{ 850 return (debug_entry_t *) (((char *) id->areas[id->active_area] 851 [id->active_pages[id->active_area]]) + 852 id->active_entries[id->active_area]); 853} 854 855/* 856 * debug_finish_entry: 857 * - set timestamp, caller address, cpu number etc. 858 */ 859 860static inline void 861debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level, 862 int exception) 863{ 864 active->id.stck = get_clock(); 865 active->id.fields.cpuid = smp_processor_id(); 866 active->caller = __builtin_return_address(0); 867 active->id.fields.exception = exception; 868 active->id.fields.level = level; 869 proceed_active_entry(id); 870 if(exception) 871 proceed_active_area(id); 872} 873 874static int debug_stoppable=1; 875static int debug_active=1; 876 877#define CTL_S390DBF_STOPPABLE 5678 878#define CTL_S390DBF_ACTIVE 5679 879 880/* 881 * proc handler for the running debug_active sysctl 882 * always allow read, allow write only if debug_stoppable is set or 883 * if debug_active is already off 884 */ 885static int 886s390dbf_procactive(ctl_table *table, int write, 887 void __user *buffer, size_t *lenp, loff_t *ppos) 888{ 889 if (!write || debug_stoppable || !debug_active) 890 return proc_dointvec(table, write, buffer, lenp, ppos); 891 else 892 return 0; 893} 894 895 896static struct ctl_table s390dbf_table[] = { 897 { 898 .procname = "debug_stoppable", 899 .data = &debug_stoppable, 900 .maxlen = sizeof(int), 901 .mode = S_IRUGO | S_IWUSR, 902 .proc_handler = proc_dointvec, 903 }, 904 { 905 .procname = "debug_active", 906 .data = &debug_active, 907 .maxlen = sizeof(int), 908 .mode = S_IRUGO | S_IWUSR, 909 .proc_handler = s390dbf_procactive, 910 }, 911 { } 912}; 913 914static struct ctl_table s390dbf_dir_table[] = { 915 { 916 .procname = "s390dbf", 917 .maxlen = 0, 918 .mode = S_IRUGO | S_IXUGO, 919 .child = s390dbf_table, 920 }, 921 { } 922}; 923 924static struct ctl_table_header *s390dbf_sysctl_header; 925 926void 927debug_stop_all(void) 928{ 929 if (debug_stoppable) 930 debug_active = 0; 931} 932 933 934/* 935 * debug_event_common: 936 * - write debug entry with given size 937 */ 938 939debug_entry_t* 940debug_event_common(debug_info_t * id, int level, const void *buf, int len) 941{ 942 unsigned long flags; 943 debug_entry_t *active; 944 945 if (!debug_active || !id->areas) 946 return NULL; 947 spin_lock_irqsave(&id->lock, flags); 948 active = get_active_entry(id); 949 memset(DEBUG_DATA(active), 0, id->buf_size); 950 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 951 debug_finish_entry(id, active, level, 0); 952 spin_unlock_irqrestore(&id->lock, flags); 953 954 return active; 955} 956 957/* 958 * debug_exception_common: 959 * - write debug entry with given size and switch to next debug area 960 */ 961 962debug_entry_t 963*debug_exception_common(debug_info_t * id, int level, const void *buf, int len) 964{ 965 unsigned long flags; 966 debug_entry_t *active; 967 968 if (!debug_active || !id->areas) 969 return NULL; 970 spin_lock_irqsave(&id->lock, flags); 971 active = get_active_entry(id); 972 memset(DEBUG_DATA(active), 0, id->buf_size); 973 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 974 debug_finish_entry(id, active, level, 1); 975 spin_unlock_irqrestore(&id->lock, flags); 976 977 return active; 978} 979 980/* 981 * counts arguments in format string for sprintf view 982 */ 983 984static inline int 985debug_count_numargs(char *string) 986{ 987 int numargs=0; 988 989 while(*string) { 990 if(*string++=='%') 991 numargs++; 992 } 993 return(numargs); 994} 995 996/* 997 * debug_sprintf_event: 998 */ 999 1000debug_entry_t* 1001debug_sprintf_event(debug_info_t* id, int level,char *string,...) 1002{ 1003 va_list ap; 1004 int numargs,idx; 1005 unsigned long flags; 1006 debug_sprintf_entry_t *curr_event; 1007 debug_entry_t *active; 1008 1009 if((!id) || (level > id->level)) 1010 return NULL; 1011 if (!debug_active || !id->areas) 1012 return NULL; 1013 numargs=debug_count_numargs(string); 1014 1015 spin_lock_irqsave(&id->lock, flags); 1016 active = get_active_entry(id); 1017 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active); 1018 va_start(ap,string); 1019 curr_event->string=string; 1020 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1021 curr_event->args[idx]=va_arg(ap,long); 1022 va_end(ap); 1023 debug_finish_entry(id, active, level, 0); 1024 spin_unlock_irqrestore(&id->lock, flags); 1025 1026 return active; 1027} 1028 1029/* 1030 * debug_sprintf_exception: 1031 */ 1032 1033debug_entry_t* 1034debug_sprintf_exception(debug_info_t* id, int level,char *string,...) 1035{ 1036 va_list ap; 1037 int numargs,idx; 1038 unsigned long flags; 1039 debug_sprintf_entry_t *curr_event; 1040 debug_entry_t *active; 1041 1042 if((!id) || (level > id->level)) 1043 return NULL; 1044 if (!debug_active || !id->areas) 1045 return NULL; 1046 1047 numargs=debug_count_numargs(string); 1048 1049 spin_lock_irqsave(&id->lock, flags); 1050 active = get_active_entry(id); 1051 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active); 1052 va_start(ap,string); 1053 curr_event->string=string; 1054 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1055 curr_event->args[idx]=va_arg(ap,long); 1056 va_end(ap); 1057 debug_finish_entry(id, active, level, 1); 1058 spin_unlock_irqrestore(&id->lock, flags); 1059 1060 return active; 1061} 1062 1063/* 1064 * debug_init: 1065 * - is called exactly once to initialize the debug feature 1066 */ 1067 1068static int 1069__init debug_init(void) 1070{ 1071 int rc = 0; 1072 1073 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1074 mutex_lock(&debug_mutex); 1075 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL); 1076 initialized = 1; 1077 mutex_unlock(&debug_mutex); 1078 1079 return rc; 1080} 1081 1082/* 1083 * debug_register_view: 1084 */ 1085 1086int 1087debug_register_view(debug_info_t * id, struct debug_view *view) 1088{ 1089 int rc = 0; 1090 int i; 1091 unsigned long flags; 1092 mode_t mode; 1093 struct dentry *pde; 1094 1095 if (!id) 1096 goto out; 1097 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1098 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1099 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1100 if (!view->input_proc) 1101 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1102 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1103 id , &debug_file_ops); 1104 if (!pde){ 1105 pr_err("Registering view %s/%s failed due to out of " 1106 "memory\n", id->name,view->name); 1107 rc = -1; 1108 goto out; 1109 } 1110 spin_lock_irqsave(&id->lock, flags); 1111 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1112 if (!id->views[i]) 1113 break; 1114 } 1115 if (i == DEBUG_MAX_VIEWS) { 1116 pr_err("Registering view %s/%s would exceed the maximum " 1117 "number of views %i\n", id->name, view->name, i); 1118 debugfs_remove(pde); 1119 rc = -1; 1120 } else { 1121 id->views[i] = view; 1122 id->debugfs_entries[i] = pde; 1123 } 1124 spin_unlock_irqrestore(&id->lock, flags); 1125out: 1126 return rc; 1127} 1128 1129/* 1130 * debug_unregister_view: 1131 */ 1132 1133int 1134debug_unregister_view(debug_info_t * id, struct debug_view *view) 1135{ 1136 int rc = 0; 1137 int i; 1138 unsigned long flags; 1139 1140 if (!id) 1141 goto out; 1142 spin_lock_irqsave(&id->lock, flags); 1143 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1144 if (id->views[i] == view) 1145 break; 1146 } 1147 if (i == DEBUG_MAX_VIEWS) 1148 rc = -1; 1149 else { 1150 debugfs_remove(id->debugfs_entries[i]); 1151 id->views[i] = NULL; 1152 } 1153 spin_unlock_irqrestore(&id->lock, flags); 1154out: 1155 return rc; 1156} 1157 1158static inline char * 1159debug_get_user_string(const char __user *user_buf, size_t user_len) 1160{ 1161 char* buffer; 1162 1163 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1164 if (!buffer) 1165 return ERR_PTR(-ENOMEM); 1166 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1167 kfree(buffer); 1168 return ERR_PTR(-EFAULT); 1169 } 1170 /* got the string, now strip linefeed. */ 1171 if (buffer[user_len - 1] == '\n') 1172 buffer[user_len - 1] = 0; 1173 else 1174 buffer[user_len] = 0; 1175 return buffer; 1176} 1177 1178static inline int 1179debug_get_uint(char *buf) 1180{ 1181 int rc; 1182 1183 buf = skip_spaces(buf); 1184 rc = simple_strtoul(buf, &buf, 10); 1185 if(*buf){ 1186 rc = -EINVAL; 1187 } 1188 return rc; 1189} 1190 1191/* 1192 * functions for debug-views 1193 *********************************** 1194*/ 1195 1196/* 1197 * prints out actual debug level 1198 */ 1199 1200static int 1201debug_prolog_pages_fn(debug_info_t * id, 1202 struct debug_view *view, char *out_buf) 1203{ 1204 return sprintf(out_buf, "%i\n", id->pages_per_area); 1205} 1206 1207/* 1208 * reads new size (number of pages per debug area) 1209 */ 1210 1211static int 1212debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 1213 struct file *file, const char __user *user_buf, 1214 size_t user_len, loff_t * offset) 1215{ 1216 char *str; 1217 int rc,new_pages; 1218 1219 if (user_len > 0x10000) 1220 user_len = 0x10000; 1221 if (*offset != 0){ 1222 rc = -EPIPE; 1223 goto out; 1224 } 1225 str = debug_get_user_string(user_buf,user_len); 1226 if(IS_ERR(str)){ 1227 rc = PTR_ERR(str); 1228 goto out; 1229 } 1230 new_pages = debug_get_uint(str); 1231 if(new_pages < 0){ 1232 rc = -EINVAL; 1233 goto free_str; 1234 } 1235 rc = debug_set_size(id,id->nr_areas, new_pages); 1236 if(rc != 0){ 1237 rc = -EINVAL; 1238 goto free_str; 1239 } 1240 rc = user_len; 1241free_str: 1242 kfree(str); 1243out: 1244 *offset += user_len; 1245 return rc; /* number of input characters */ 1246} 1247 1248/* 1249 * prints out actual debug level 1250 */ 1251 1252static int 1253debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf) 1254{ 1255 int rc = 0; 1256 1257 if(id->level == DEBUG_OFF_LEVEL) { 1258 rc = sprintf(out_buf,"-\n"); 1259 } 1260 else { 1261 rc = sprintf(out_buf, "%i\n", id->level); 1262 } 1263 return rc; 1264} 1265 1266/* 1267 * reads new debug level 1268 */ 1269 1270static int 1271debug_input_level_fn(debug_info_t * id, struct debug_view *view, 1272 struct file *file, const char __user *user_buf, 1273 size_t user_len, loff_t * offset) 1274{ 1275 char *str; 1276 int rc,new_level; 1277 1278 if (user_len > 0x10000) 1279 user_len = 0x10000; 1280 if (*offset != 0){ 1281 rc = -EPIPE; 1282 goto out; 1283 } 1284 str = debug_get_user_string(user_buf,user_len); 1285 if(IS_ERR(str)){ 1286 rc = PTR_ERR(str); 1287 goto out; 1288 } 1289 if(str[0] == '-'){ 1290 debug_set_level(id, DEBUG_OFF_LEVEL); 1291 rc = user_len; 1292 goto free_str; 1293 } else { 1294 new_level = debug_get_uint(str); 1295 } 1296 if(new_level < 0) { 1297 pr_warning("%s is not a valid level for a debug " 1298 "feature\n", str); 1299 rc = -EINVAL; 1300 } else { 1301 debug_set_level(id, new_level); 1302 rc = user_len; 1303 } 1304free_str: 1305 kfree(str); 1306out: 1307 *offset += user_len; 1308 return rc; /* number of input characters */ 1309} 1310 1311 1312/* 1313 * flushes debug areas 1314 */ 1315 1316static void debug_flush(debug_info_t* id, int area) 1317{ 1318 unsigned long flags; 1319 int i,j; 1320 1321 if(!id || !id->areas) 1322 return; 1323 spin_lock_irqsave(&id->lock,flags); 1324 if(area == DEBUG_FLUSH_ALL){ 1325 id->active_area = 0; 1326 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1327 for (i = 0; i < id->nr_areas; i++) { 1328 id->active_pages[i] = 0; 1329 for(j = 0; j < id->pages_per_area; j++) { 1330 memset(id->areas[i][j], 0, PAGE_SIZE); 1331 } 1332 } 1333 } else if(area >= 0 && area < id->nr_areas) { 1334 id->active_entries[area] = 0; 1335 id->active_pages[area] = 0; 1336 for(i = 0; i < id->pages_per_area; i++) { 1337 memset(id->areas[area][i],0,PAGE_SIZE); 1338 } 1339 } 1340 spin_unlock_irqrestore(&id->lock,flags); 1341} 1342 1343/* 1344 * view function: flushes debug areas 1345 */ 1346 1347static int 1348debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 1349 struct file *file, const char __user *user_buf, 1350 size_t user_len, loff_t * offset) 1351{ 1352 char input_buf[1]; 1353 int rc = user_len; 1354 1355 if (user_len > 0x10000) 1356 user_len = 0x10000; 1357 if (*offset != 0){ 1358 rc = -EPIPE; 1359 goto out; 1360 } 1361 if (copy_from_user(input_buf, user_buf, 1)){ 1362 rc = -EFAULT; 1363 goto out; 1364 } 1365 if(input_buf[0] == '-') { 1366 debug_flush(id, DEBUG_FLUSH_ALL); 1367 goto out; 1368 } 1369 if (isdigit(input_buf[0])) { 1370 int area = ((int) input_buf[0] - (int) '0'); 1371 debug_flush(id, area); 1372 goto out; 1373 } 1374 1375 pr_info("Flushing debug data failed because %c is not a valid " 1376 "area\n", input_buf[0]); 1377 1378out: 1379 *offset += user_len; 1380 return rc; /* number of input characters */ 1381} 1382 1383/* 1384 * prints debug header in raw format 1385 */ 1386 1387static int 1388debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 1389 int area, debug_entry_t * entry, char *out_buf) 1390{ 1391 int rc; 1392 1393 rc = sizeof(debug_entry_t); 1394 memcpy(out_buf,entry,sizeof(debug_entry_t)); 1395 return rc; 1396} 1397 1398/* 1399 * prints debug data in raw format 1400 */ 1401 1402static int 1403debug_raw_format_fn(debug_info_t * id, struct debug_view *view, 1404 char *out_buf, const char *in_buf) 1405{ 1406 int rc; 1407 1408 rc = id->buf_size; 1409 memcpy(out_buf, in_buf, id->buf_size); 1410 return rc; 1411} 1412 1413/* 1414 * prints debug data in hex/ascii format 1415 */ 1416 1417static int 1418debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 1419 char *out_buf, const char *in_buf) 1420{ 1421 int i, rc = 0; 1422 1423 for (i = 0; i < id->buf_size; i++) { 1424 rc += sprintf(out_buf + rc, "%02x ", 1425 ((unsigned char *) in_buf)[i]); 1426 } 1427 rc += sprintf(out_buf + rc, "| "); 1428 for (i = 0; i < id->buf_size; i++) { 1429 unsigned char c = in_buf[i]; 1430 if (!isprint(c)) 1431 rc += sprintf(out_buf + rc, "."); 1432 else 1433 rc += sprintf(out_buf + rc, "%c", c); 1434 } 1435 rc += sprintf(out_buf + rc, "\n"); 1436 return rc; 1437} 1438 1439/* 1440 * prints header for debug entry 1441 */ 1442 1443int 1444debug_dflt_header_fn(debug_info_t * id, struct debug_view *view, 1445 int area, debug_entry_t * entry, char *out_buf) 1446{ 1447 struct timespec time_spec; 1448 char *except_str; 1449 unsigned long caller; 1450 int rc = 0; 1451 unsigned int level; 1452 1453 level = entry->id.fields.level; 1454 stck_to_timespec(entry->id.stck, &time_spec); 1455 1456 if (entry->id.fields.exception) 1457 except_str = "*"; 1458 else 1459 except_str = "-"; 1460 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN; 1461 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ", 1462 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level, 1463 except_str, entry->id.fields.cpuid, (void *) caller); 1464 return rc; 1465} 1466 1467/* 1468 * prints debug data sprintf-formated: 1469 * debug_sprinf_event/exception calls must be used together with this view 1470 */ 1471 1472#define DEBUG_SPRINTF_MAX_ARGS 10 1473 1474static int 1475debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 1476 char *out_buf, debug_sprintf_entry_t *curr_event) 1477{ 1478 int num_longs, num_used_args = 0,i, rc = 0; 1479 int index[DEBUG_SPRINTF_MAX_ARGS]; 1480 1481 /* count of longs fit into one entry */ 1482 num_longs = id->buf_size / sizeof(long); 1483 1484 if(num_longs < 1) 1485 goto out; /* bufsize of entry too small */ 1486 if(num_longs == 1) { 1487 /* no args, we use only the string */ 1488 strcpy(out_buf, curr_event->string); 1489 rc = strlen(curr_event->string); 1490 goto out; 1491 } 1492 1493 /* number of arguments used for sprintf (without the format string) */ 1494 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1495 1496 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1497 1498 for(i = 0; i < num_used_args; i++) 1499 index[i] = i; 1500 1501 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1502 curr_event->args[index[1]], curr_event->args[index[2]], 1503 curr_event->args[index[3]], curr_event->args[index[4]], 1504 curr_event->args[index[5]], curr_event->args[index[6]], 1505 curr_event->args[index[7]], curr_event->args[index[8]], 1506 curr_event->args[index[9]]); 1507 1508out: 1509 1510 return rc; 1511} 1512 1513/* 1514 * clean up module 1515 */ 1516static void __exit debug_exit(void) 1517{ 1518 debugfs_remove(debug_debugfs_root_entry); 1519 unregister_sysctl_table(s390dbf_sysctl_header); 1520 return; 1521} 1522 1523/* 1524 * module definitions 1525 */ 1526postcore_initcall(debug_init); 1527module_exit(debug_exit); 1528MODULE_LICENSE("GPL"); 1529 1530EXPORT_SYMBOL(debug_register); 1531EXPORT_SYMBOL(debug_unregister); 1532EXPORT_SYMBOL(debug_set_level); 1533EXPORT_SYMBOL(debug_stop_all); 1534EXPORT_SYMBOL(debug_register_view); 1535EXPORT_SYMBOL(debug_unregister_view); 1536EXPORT_SYMBOL(debug_event_common); 1537EXPORT_SYMBOL(debug_exception_common); 1538EXPORT_SYMBOL(debug_hex_ascii_view); 1539EXPORT_SYMBOL(debug_raw_view); 1540EXPORT_SYMBOL(debug_dflt_header_fn); 1541EXPORT_SYMBOL(debug_sprintf_view); 1542EXPORT_SYMBOL(debug_sprintf_exception); 1543EXPORT_SYMBOL(debug_sprintf_event); 1544