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 37typedef 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 53typedef 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 68static int debug_init(void); 69static ssize_t debug_output(struct file *file, char __user *user_buf, 70 size_t user_len, loff_t * offset); 71static ssize_t debug_input(struct file *file, const char __user *user_buf, 72 size_t user_len, loff_t * offset); 73static int debug_open(struct inode *inode, struct file *file); 74static int debug_close(struct inode *inode, struct file *file); 75static debug_info_t *debug_info_create(const char *name, int pages_per_area, 76 int nr_areas, int buf_size, umode_t mode); 77static void debug_info_get(debug_info_t *); 78static void debug_info_put(debug_info_t *); 79static int debug_prolog_level_fn(debug_info_t * id, 80 struct debug_view *view, char *out_buf); 81static 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); 84static int debug_prolog_pages_fn(debug_info_t * id, 85 struct debug_view *view, char *out_buf); 86static 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); 89static 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); 92static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 93 char *out_buf, const char *in_buf); 94static int debug_raw_format_fn(debug_info_t * id, 95 struct debug_view *view, char *out_buf, 96 const char *in_buf); 97static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 98 int area, debug_entry_t * entry, char *out_buf); 99 100static 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 105struct debug_view debug_raw_view = { 106 "raw", 107 NULL, 108 &debug_raw_header_fn, 109 &debug_raw_format_fn, 110 NULL, 111 NULL 112}; 113EXPORT_SYMBOL(debug_raw_view); 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}; 123EXPORT_SYMBOL(debug_hex_ascii_view); 124 125static 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 134static 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 143static struct debug_view debug_flush_view = { 144 "flush", 145 NULL, 146 NULL, 147 NULL, 148 &debug_input_flush_fn, 149 NULL 150}; 151 152struct 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}; 160EXPORT_SYMBOL(debug_sprintf_view); 161 162/* used by dump analysis tools to determine version of debug feature */ 163static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 164 165/* static globals */ 166 167static debug_info_t *debug_area_first = NULL; 168static debug_info_t *debug_area_last = NULL; 169static DEFINE_MUTEX(debug_mutex); 170 171static int initialized; 172static int debug_critical; 173 174static 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 183static 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 193static debug_entry_t*** 194debug_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 223fail_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); 231fail_malloc_areas: 232 return NULL; 233 234} 235 236 237/* 238 * debug_info_alloc 239 * - alloc new debug-info 240 */ 241 242static debug_info_t* 243debug_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 284fail_malloc_areas: 285 kfree(rc->active_pages); 286fail_malloc_active_pages: 287 kfree(rc->active_entries); 288fail_malloc_active_entries: 289 kfree(rc); 290fail_malloc_rc: 291 return NULL; 292} 293 294/* 295 * debug_areas_free 296 * - free all debug areas 297 */ 298 299static void 300debug_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 321static void 322debug_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 334static debug_info_t* 335debug_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); 365out: 366 return rc; 367} 368 369/* 370 * debug_info_copy 371 * - copy debug-info 372 */ 373 374static debug_info_t* 375debug_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 } 405out: 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 415static void 416debug_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 427static void 428debug_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 456static int 457debug_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)); 482out: 483 return len; 484} 485 486/* 487 * debug_next_entry: 488 * - goto next entry in p_info 489 */ 490 491static inline int 492debug_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 } 518out: 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 528static ssize_t 529debug_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 } 567out: 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 580static ssize_t 581debug_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 606static int 607debug_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 628found: 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); 663out: 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 674static int 675debug_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 693debug_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_warning("Root becomes the owner of all s390dbf files " 703 "in sysfs\n"); 704 BUG_ON(!initialized); 705 mutex_lock(&debug_mutex); 706 707 /* create new debug_info */ 708 709 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 710 if(!rc) 711 goto out; 712 debug_register_view(rc, &debug_level_view); 713 debug_register_view(rc, &debug_flush_view); 714 debug_register_view(rc, &debug_pages_view); 715out: 716 if (!rc){ 717 pr_err("Registering debug feature %s failed\n", name); 718 } 719 mutex_unlock(&debug_mutex); 720 return rc; 721} 722EXPORT_SYMBOL(debug_register_mode); 723 724/* 725 * debug_register: 726 * - creates and initializes debug area for the caller 727 * - returns handle for debug area 728 */ 729 730debug_info_t *debug_register(const char *name, int pages_per_area, 731 int nr_areas, int buf_size) 732{ 733 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 734 S_IRUSR | S_IWUSR, 0, 0); 735} 736EXPORT_SYMBOL(debug_register); 737 738/* 739 * debug_unregister: 740 * - give back debug area 741 */ 742 743void 744debug_unregister(debug_info_t * id) 745{ 746 if (!id) 747 goto out; 748 mutex_lock(&debug_mutex); 749 debug_info_put(id); 750 mutex_unlock(&debug_mutex); 751 752out: 753 return; 754} 755EXPORT_SYMBOL(debug_unregister); 756 757/* 758 * debug_set_size: 759 * - set area size (number of pages) and number of areas 760 */ 761static int 762debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area) 763{ 764 unsigned long flags; 765 debug_entry_t *** new_areas; 766 int rc=0; 767 768 if(!id || (nr_areas <= 0) || (pages_per_area < 0)) 769 return -EINVAL; 770 if(pages_per_area > 0){ 771 new_areas = debug_areas_alloc(pages_per_area, nr_areas); 772 if(!new_areas) { 773 pr_info("Allocating memory for %i pages failed\n", 774 pages_per_area); 775 rc = -ENOMEM; 776 goto out; 777 } 778 } else { 779 new_areas = NULL; 780 } 781 spin_lock_irqsave(&id->lock,flags); 782 debug_areas_free(id); 783 id->areas = new_areas; 784 id->nr_areas = nr_areas; 785 id->pages_per_area = pages_per_area; 786 id->active_area = 0; 787 memset(id->active_entries,0,sizeof(int)*id->nr_areas); 788 memset(id->active_pages, 0, sizeof(int)*id->nr_areas); 789 spin_unlock_irqrestore(&id->lock,flags); 790 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area); 791out: 792 return rc; 793} 794 795/* 796 * debug_set_level: 797 * - set actual debug level 798 */ 799 800void 801debug_set_level(debug_info_t* id, int new_level) 802{ 803 unsigned long flags; 804 if(!id) 805 return; 806 spin_lock_irqsave(&id->lock,flags); 807 if(new_level == DEBUG_OFF_LEVEL){ 808 id->level = DEBUG_OFF_LEVEL; 809 pr_info("%s: switched off\n",id->name); 810 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 811 pr_info("%s: level %i is out of range (%i - %i)\n", 812 id->name, new_level, 0, DEBUG_MAX_LEVEL); 813 } else { 814 id->level = new_level; 815 } 816 spin_unlock_irqrestore(&id->lock,flags); 817} 818EXPORT_SYMBOL(debug_set_level); 819 820/* 821 * proceed_active_entry: 822 * - set active entry to next in the ring buffer 823 */ 824 825static inline void 826proceed_active_entry(debug_info_t * id) 827{ 828 if ((id->active_entries[id->active_area] += id->entry_size) 829 > (PAGE_SIZE - id->entry_size)){ 830 id->active_entries[id->active_area] = 0; 831 id->active_pages[id->active_area] = 832 (id->active_pages[id->active_area] + 1) % 833 id->pages_per_area; 834 } 835} 836 837/* 838 * proceed_active_area: 839 * - set active area to next in the ring buffer 840 */ 841 842static inline void 843proceed_active_area(debug_info_t * id) 844{ 845 id->active_area++; 846 id->active_area = id->active_area % id->nr_areas; 847} 848 849/* 850 * get_active_entry: 851 */ 852 853static inline debug_entry_t* 854get_active_entry(debug_info_t * id) 855{ 856 return (debug_entry_t *) (((char *) id->areas[id->active_area] 857 [id->active_pages[id->active_area]]) + 858 id->active_entries[id->active_area]); 859} 860 861/* 862 * debug_finish_entry: 863 * - set timestamp, caller address, cpu number etc. 864 */ 865 866static inline void 867debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level, 868 int exception) 869{ 870 active->id.stck = get_tod_clock_fast(); 871 active->id.fields.cpuid = smp_processor_id(); 872 active->caller = __builtin_return_address(0); 873 active->id.fields.exception = exception; 874 active->id.fields.level = level; 875 proceed_active_entry(id); 876 if(exception) 877 proceed_active_area(id); 878} 879 880static int debug_stoppable=1; 881static int debug_active=1; 882 883#define CTL_S390DBF_STOPPABLE 5678 884#define CTL_S390DBF_ACTIVE 5679 885 886/* 887 * proc handler for the running debug_active sysctl 888 * always allow read, allow write only if debug_stoppable is set or 889 * if debug_active is already off 890 */ 891static int 892s390dbf_procactive(struct ctl_table *table, int write, 893 void __user *buffer, size_t *lenp, loff_t *ppos) 894{ 895 if (!write || debug_stoppable || !debug_active) 896 return proc_dointvec(table, write, buffer, lenp, ppos); 897 else 898 return 0; 899} 900 901 902static struct ctl_table s390dbf_table[] = { 903 { 904 .procname = "debug_stoppable", 905 .data = &debug_stoppable, 906 .maxlen = sizeof(int), 907 .mode = S_IRUGO | S_IWUSR, 908 .proc_handler = proc_dointvec, 909 }, 910 { 911 .procname = "debug_active", 912 .data = &debug_active, 913 .maxlen = sizeof(int), 914 .mode = S_IRUGO | S_IWUSR, 915 .proc_handler = s390dbf_procactive, 916 }, 917 { } 918}; 919 920static struct ctl_table s390dbf_dir_table[] = { 921 { 922 .procname = "s390dbf", 923 .maxlen = 0, 924 .mode = S_IRUGO | S_IXUGO, 925 .child = s390dbf_table, 926 }, 927 { } 928}; 929 930static struct ctl_table_header *s390dbf_sysctl_header; 931 932void 933debug_stop_all(void) 934{ 935 if (debug_stoppable) 936 debug_active = 0; 937} 938EXPORT_SYMBOL(debug_stop_all); 939 940void debug_set_critical(void) 941{ 942 debug_critical = 1; 943} 944 945/* 946 * debug_event_common: 947 * - write debug entry with given size 948 */ 949 950debug_entry_t* 951debug_event_common(debug_info_t * id, int level, const void *buf, int len) 952{ 953 unsigned long flags; 954 debug_entry_t *active; 955 956 if (!debug_active || !id->areas) 957 return NULL; 958 if (debug_critical) { 959 if (!spin_trylock_irqsave(&id->lock, flags)) 960 return NULL; 961 } else 962 spin_lock_irqsave(&id->lock, flags); 963 active = get_active_entry(id); 964 memset(DEBUG_DATA(active), 0, id->buf_size); 965 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 966 debug_finish_entry(id, active, level, 0); 967 spin_unlock_irqrestore(&id->lock, flags); 968 969 return active; 970} 971EXPORT_SYMBOL(debug_event_common); 972 973/* 974 * debug_exception_common: 975 * - write debug entry with given size and switch to next debug area 976 */ 977 978debug_entry_t 979*debug_exception_common(debug_info_t * id, int level, const void *buf, int len) 980{ 981 unsigned long flags; 982 debug_entry_t *active; 983 984 if (!debug_active || !id->areas) 985 return NULL; 986 if (debug_critical) { 987 if (!spin_trylock_irqsave(&id->lock, flags)) 988 return NULL; 989 } else 990 spin_lock_irqsave(&id->lock, flags); 991 active = get_active_entry(id); 992 memset(DEBUG_DATA(active), 0, id->buf_size); 993 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 994 debug_finish_entry(id, active, level, 1); 995 spin_unlock_irqrestore(&id->lock, flags); 996 997 return active; 998} 999EXPORT_SYMBOL(debug_exception_common); 1000 1001/* 1002 * counts arguments in format string for sprintf view 1003 */ 1004 1005static inline int 1006debug_count_numargs(char *string) 1007{ 1008 int numargs=0; 1009 1010 while(*string) { 1011 if(*string++=='%') 1012 numargs++; 1013 } 1014 return(numargs); 1015} 1016 1017/* 1018 * debug_sprintf_event: 1019 */ 1020 1021debug_entry_t* 1022debug_sprintf_event(debug_info_t* id, int level,char *string,...) 1023{ 1024 va_list ap; 1025 int numargs,idx; 1026 unsigned long flags; 1027 debug_sprintf_entry_t *curr_event; 1028 debug_entry_t *active; 1029 1030 if((!id) || (level > id->level)) 1031 return NULL; 1032 if (!debug_active || !id->areas) 1033 return NULL; 1034 numargs=debug_count_numargs(string); 1035 1036 if (debug_critical) { 1037 if (!spin_trylock_irqsave(&id->lock, flags)) 1038 return NULL; 1039 } else 1040 spin_lock_irqsave(&id->lock, flags); 1041 active = get_active_entry(id); 1042 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active); 1043 va_start(ap,string); 1044 curr_event->string=string; 1045 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1046 curr_event->args[idx]=va_arg(ap,long); 1047 va_end(ap); 1048 debug_finish_entry(id, active, level, 0); 1049 spin_unlock_irqrestore(&id->lock, flags); 1050 1051 return active; 1052} 1053EXPORT_SYMBOL(debug_sprintf_event); 1054 1055/* 1056 * debug_sprintf_exception: 1057 */ 1058 1059debug_entry_t* 1060debug_sprintf_exception(debug_info_t* id, int level,char *string,...) 1061{ 1062 va_list ap; 1063 int numargs,idx; 1064 unsigned long flags; 1065 debug_sprintf_entry_t *curr_event; 1066 debug_entry_t *active; 1067 1068 if((!id) || (level > id->level)) 1069 return NULL; 1070 if (!debug_active || !id->areas) 1071 return NULL; 1072 1073 numargs=debug_count_numargs(string); 1074 1075 if (debug_critical) { 1076 if (!spin_trylock_irqsave(&id->lock, flags)) 1077 return NULL; 1078 } else 1079 spin_lock_irqsave(&id->lock, flags); 1080 active = get_active_entry(id); 1081 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active); 1082 va_start(ap,string); 1083 curr_event->string=string; 1084 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++) 1085 curr_event->args[idx]=va_arg(ap,long); 1086 va_end(ap); 1087 debug_finish_entry(id, active, level, 1); 1088 spin_unlock_irqrestore(&id->lock, flags); 1089 1090 return active; 1091} 1092EXPORT_SYMBOL(debug_sprintf_exception); 1093 1094/* 1095 * debug_register_view: 1096 */ 1097 1098int 1099debug_register_view(debug_info_t * id, struct debug_view *view) 1100{ 1101 int rc = 0; 1102 int i; 1103 unsigned long flags; 1104 umode_t mode; 1105 struct dentry *pde; 1106 1107 if (!id) 1108 goto out; 1109 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1110 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1111 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1112 if (!view->input_proc) 1113 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1114 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1115 id , &debug_file_ops); 1116 if (!pde){ 1117 pr_err("Registering view %s/%s failed due to out of " 1118 "memory\n", id->name,view->name); 1119 rc = -1; 1120 goto out; 1121 } 1122 spin_lock_irqsave(&id->lock, flags); 1123 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1124 if (!id->views[i]) 1125 break; 1126 } 1127 if (i == DEBUG_MAX_VIEWS) { 1128 pr_err("Registering view %s/%s would exceed the maximum " 1129 "number of views %i\n", id->name, view->name, i); 1130 rc = -1; 1131 } else { 1132 id->views[i] = view; 1133 id->debugfs_entries[i] = pde; 1134 } 1135 spin_unlock_irqrestore(&id->lock, flags); 1136 if (rc) 1137 debugfs_remove(pde); 1138out: 1139 return rc; 1140} 1141EXPORT_SYMBOL(debug_register_view); 1142 1143/* 1144 * debug_unregister_view: 1145 */ 1146 1147int 1148debug_unregister_view(debug_info_t * id, struct debug_view *view) 1149{ 1150 struct dentry *dentry = NULL; 1151 unsigned long flags; 1152 int i, rc = 0; 1153 1154 if (!id) 1155 goto out; 1156 spin_lock_irqsave(&id->lock, flags); 1157 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1158 if (id->views[i] == view) 1159 break; 1160 } 1161 if (i == DEBUG_MAX_VIEWS) 1162 rc = -1; 1163 else { 1164 dentry = id->debugfs_entries[i]; 1165 id->views[i] = NULL; 1166 id->debugfs_entries[i] = NULL; 1167 } 1168 spin_unlock_irqrestore(&id->lock, flags); 1169 debugfs_remove(dentry); 1170out: 1171 return rc; 1172} 1173EXPORT_SYMBOL(debug_unregister_view); 1174 1175static inline char * 1176debug_get_user_string(const char __user *user_buf, size_t user_len) 1177{ 1178 char* buffer; 1179 1180 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1181 if (!buffer) 1182 return ERR_PTR(-ENOMEM); 1183 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1184 kfree(buffer); 1185 return ERR_PTR(-EFAULT); 1186 } 1187 /* got the string, now strip linefeed. */ 1188 if (buffer[user_len - 1] == '\n') 1189 buffer[user_len - 1] = 0; 1190 else 1191 buffer[user_len] = 0; 1192 return buffer; 1193} 1194 1195static inline int 1196debug_get_uint(char *buf) 1197{ 1198 int rc; 1199 1200 buf = skip_spaces(buf); 1201 rc = simple_strtoul(buf, &buf, 10); 1202 if(*buf){ 1203 rc = -EINVAL; 1204 } 1205 return rc; 1206} 1207 1208/* 1209 * functions for debug-views 1210 *********************************** 1211*/ 1212 1213/* 1214 * prints out actual debug level 1215 */ 1216 1217static int 1218debug_prolog_pages_fn(debug_info_t * id, 1219 struct debug_view *view, char *out_buf) 1220{ 1221 return sprintf(out_buf, "%i\n", id->pages_per_area); 1222} 1223 1224/* 1225 * reads new size (number of pages per debug area) 1226 */ 1227 1228static int 1229debug_input_pages_fn(debug_info_t * id, struct debug_view *view, 1230 struct file *file, const char __user *user_buf, 1231 size_t user_len, loff_t * offset) 1232{ 1233 char *str; 1234 int rc,new_pages; 1235 1236 if (user_len > 0x10000) 1237 user_len = 0x10000; 1238 if (*offset != 0){ 1239 rc = -EPIPE; 1240 goto out; 1241 } 1242 str = debug_get_user_string(user_buf,user_len); 1243 if(IS_ERR(str)){ 1244 rc = PTR_ERR(str); 1245 goto out; 1246 } 1247 new_pages = debug_get_uint(str); 1248 if(new_pages < 0){ 1249 rc = -EINVAL; 1250 goto free_str; 1251 } 1252 rc = debug_set_size(id,id->nr_areas, new_pages); 1253 if(rc != 0){ 1254 rc = -EINVAL; 1255 goto free_str; 1256 } 1257 rc = user_len; 1258free_str: 1259 kfree(str); 1260out: 1261 *offset += user_len; 1262 return rc; /* number of input characters */ 1263} 1264 1265/* 1266 * prints out actual debug level 1267 */ 1268 1269static int 1270debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf) 1271{ 1272 int rc = 0; 1273 1274 if(id->level == DEBUG_OFF_LEVEL) { 1275 rc = sprintf(out_buf,"-\n"); 1276 } 1277 else { 1278 rc = sprintf(out_buf, "%i\n", id->level); 1279 } 1280 return rc; 1281} 1282 1283/* 1284 * reads new debug level 1285 */ 1286 1287static int 1288debug_input_level_fn(debug_info_t * id, struct debug_view *view, 1289 struct file *file, const char __user *user_buf, 1290 size_t user_len, loff_t * offset) 1291{ 1292 char *str; 1293 int rc,new_level; 1294 1295 if (user_len > 0x10000) 1296 user_len = 0x10000; 1297 if (*offset != 0){ 1298 rc = -EPIPE; 1299 goto out; 1300 } 1301 str = debug_get_user_string(user_buf,user_len); 1302 if(IS_ERR(str)){ 1303 rc = PTR_ERR(str); 1304 goto out; 1305 } 1306 if(str[0] == '-'){ 1307 debug_set_level(id, DEBUG_OFF_LEVEL); 1308 rc = user_len; 1309 goto free_str; 1310 } else { 1311 new_level = debug_get_uint(str); 1312 } 1313 if(new_level < 0) { 1314 pr_warning("%s is not a valid level for a debug " 1315 "feature\n", str); 1316 rc = -EINVAL; 1317 } else { 1318 debug_set_level(id, new_level); 1319 rc = user_len; 1320 } 1321free_str: 1322 kfree(str); 1323out: 1324 *offset += user_len; 1325 return rc; /* number of input characters */ 1326} 1327 1328 1329/* 1330 * flushes debug areas 1331 */ 1332 1333static void debug_flush(debug_info_t* id, int area) 1334{ 1335 unsigned long flags; 1336 int i,j; 1337 1338 if(!id || !id->areas) 1339 return; 1340 spin_lock_irqsave(&id->lock,flags); 1341 if(area == DEBUG_FLUSH_ALL){ 1342 id->active_area = 0; 1343 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1344 for (i = 0; i < id->nr_areas; i++) { 1345 id->active_pages[i] = 0; 1346 for(j = 0; j < id->pages_per_area; j++) { 1347 memset(id->areas[i][j], 0, PAGE_SIZE); 1348 } 1349 } 1350 } else if(area >= 0 && area < id->nr_areas) { 1351 id->active_entries[area] = 0; 1352 id->active_pages[area] = 0; 1353 for(i = 0; i < id->pages_per_area; i++) { 1354 memset(id->areas[area][i],0,PAGE_SIZE); 1355 } 1356 } 1357 spin_unlock_irqrestore(&id->lock,flags); 1358} 1359 1360/* 1361 * view function: flushes debug areas 1362 */ 1363 1364static int 1365debug_input_flush_fn(debug_info_t * id, struct debug_view *view, 1366 struct file *file, const char __user *user_buf, 1367 size_t user_len, loff_t * offset) 1368{ 1369 char input_buf[1]; 1370 int rc = user_len; 1371 1372 if (user_len > 0x10000) 1373 user_len = 0x10000; 1374 if (*offset != 0){ 1375 rc = -EPIPE; 1376 goto out; 1377 } 1378 if (copy_from_user(input_buf, user_buf, 1)){ 1379 rc = -EFAULT; 1380 goto out; 1381 } 1382 if(input_buf[0] == '-') { 1383 debug_flush(id, DEBUG_FLUSH_ALL); 1384 goto out; 1385 } 1386 if (isdigit(input_buf[0])) { 1387 int area = ((int) input_buf[0] - (int) '0'); 1388 debug_flush(id, area); 1389 goto out; 1390 } 1391 1392 pr_info("Flushing debug data failed because %c is not a valid " 1393 "area\n", input_buf[0]); 1394 1395out: 1396 *offset += user_len; 1397 return rc; /* number of input characters */ 1398} 1399 1400/* 1401 * prints debug header in raw format 1402 */ 1403 1404static int 1405debug_raw_header_fn(debug_info_t * id, struct debug_view *view, 1406 int area, debug_entry_t * entry, char *out_buf) 1407{ 1408 int rc; 1409 1410 rc = sizeof(debug_entry_t); 1411 memcpy(out_buf,entry,sizeof(debug_entry_t)); 1412 return rc; 1413} 1414 1415/* 1416 * prints debug data in raw format 1417 */ 1418 1419static int 1420debug_raw_format_fn(debug_info_t * id, struct debug_view *view, 1421 char *out_buf, const char *in_buf) 1422{ 1423 int rc; 1424 1425 rc = id->buf_size; 1426 memcpy(out_buf, in_buf, id->buf_size); 1427 return rc; 1428} 1429 1430/* 1431 * prints debug data in hex/ascii format 1432 */ 1433 1434static int 1435debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view, 1436 char *out_buf, const char *in_buf) 1437{ 1438 int i, rc = 0; 1439 1440 for (i = 0; i < id->buf_size; i++) { 1441 rc += sprintf(out_buf + rc, "%02x ", 1442 ((unsigned char *) in_buf)[i]); 1443 } 1444 rc += sprintf(out_buf + rc, "| "); 1445 for (i = 0; i < id->buf_size; i++) { 1446 unsigned char c = in_buf[i]; 1447 if (isascii(c) && isprint(c)) 1448 rc += sprintf(out_buf + rc, "%c", c); 1449 else 1450 rc += sprintf(out_buf + rc, "."); 1451 } 1452 rc += sprintf(out_buf + rc, "\n"); 1453 return rc; 1454} 1455 1456/* 1457 * prints header for debug entry 1458 */ 1459 1460int 1461debug_dflt_header_fn(debug_info_t * id, struct debug_view *view, 1462 int area, debug_entry_t * entry, char *out_buf) 1463{ 1464 struct timespec time_spec; 1465 char *except_str; 1466 unsigned long caller; 1467 int rc = 0; 1468 unsigned int level; 1469 1470 level = entry->id.fields.level; 1471 stck_to_timespec(entry->id.stck, &time_spec); 1472 1473 if (entry->id.fields.exception) 1474 except_str = "*"; 1475 else 1476 except_str = "-"; 1477 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN; 1478 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ", 1479 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level, 1480 except_str, entry->id.fields.cpuid, (void *) caller); 1481 return rc; 1482} 1483EXPORT_SYMBOL(debug_dflt_header_fn); 1484 1485/* 1486 * prints debug data sprintf-formated: 1487 * debug_sprinf_event/exception calls must be used together with this view 1488 */ 1489 1490#define DEBUG_SPRINTF_MAX_ARGS 10 1491 1492static int 1493debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view, 1494 char *out_buf, debug_sprintf_entry_t *curr_event) 1495{ 1496 int num_longs, num_used_args = 0,i, rc = 0; 1497 int index[DEBUG_SPRINTF_MAX_ARGS]; 1498 1499 /* count of longs fit into one entry */ 1500 num_longs = id->buf_size / sizeof(long); 1501 1502 if(num_longs < 1) 1503 goto out; /* bufsize of entry too small */ 1504 if(num_longs == 1) { 1505 /* no args, we use only the string */ 1506 strcpy(out_buf, curr_event->string); 1507 rc = strlen(curr_event->string); 1508 goto out; 1509 } 1510 1511 /* number of arguments used for sprintf (without the format string) */ 1512 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1513 1514 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1515 1516 for(i = 0; i < num_used_args; i++) 1517 index[i] = i; 1518 1519 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1520 curr_event->args[index[1]], curr_event->args[index[2]], 1521 curr_event->args[index[3]], curr_event->args[index[4]], 1522 curr_event->args[index[5]], curr_event->args[index[6]], 1523 curr_event->args[index[7]], curr_event->args[index[8]], 1524 curr_event->args[index[9]]); 1525 1526out: 1527 1528 return rc; 1529} 1530 1531/* 1532 * debug_init: 1533 * - is called exactly once to initialize the debug feature 1534 */ 1535static int __init debug_init(void) 1536{ 1537 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1538 mutex_lock(&debug_mutex); 1539 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1540 initialized = 1; 1541 mutex_unlock(&debug_mutex); 1542 return 0; 1543} 1544postcore_initcall(debug_init); 1545