1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * S/390 debug facility 4 * 5 * Copyright IBM Corp. 1999, 2020 6 * 7 * Author(s): Michael Holzheu (holzheu@de.ibm.com), 8 * Holger Smolinski (Holger.Smolinski@de.ibm.com) 9 * 10 * Bugreports to: <Linux390@de.ibm.com> 11 */ 12 13 #define KMSG_COMPONENT "s390dbf" 14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 15 16 #include <linux/stddef.h> 17 #include <linux/kernel.h> 18 #include <linux/errno.h> 19 #include <linux/slab.h> 20 #include <linux/ctype.h> 21 #include <linux/string.h> 22 #include <linux/sysctl.h> 23 #include <linux/uaccess.h> 24 #include <linux/export.h> 25 #include <linux/init.h> 26 #include <linux/fs.h> 27 #include <linux/minmax.h> 28 #include <linux/debugfs.h> 29 30 #include <asm/debug.h> 31 32 #define DEBUG_PROLOG_ENTRY -1 33 34 #define ALL_AREAS 0 /* copy all debug areas */ 35 #define NO_AREAS 1 /* copy no debug areas */ 36 37 /* typedefs */ 38 39 typedef struct file_private_info { 40 loff_t offset; /* offset of last read in file */ 41 int act_area; /* number of last formated area */ 42 int act_page; /* act page in given area */ 43 int act_entry; /* last formated entry (offset */ 44 /* relative to beginning of last */ 45 /* formated page) */ 46 size_t act_entry_offset; /* up to this offset we copied */ 47 /* in last read the last formated */ 48 /* entry to userland */ 49 char temp_buf[2048]; /* buffer for output */ 50 debug_info_t *debug_info_org; /* original debug information */ 51 debug_info_t *debug_info_snap; /* snapshot of debug information */ 52 struct debug_view *view; /* used view of debug info */ 53 } file_private_info_t; 54 55 typedef struct { 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 /* 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_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 95 char *out_buf, debug_sprintf_entry_t *curr_event); 96 static void debug_areas_swap(debug_info_t *a, debug_info_t *b); 97 static void debug_events_append(debug_info_t *dest, debug_info_t *src); 98 99 /* globals */ 100 101 struct debug_view debug_hex_ascii_view = { 102 "hex_ascii", 103 NULL, 104 &debug_dflt_header_fn, 105 &debug_hex_ascii_format_fn, 106 NULL, 107 NULL 108 }; 109 EXPORT_SYMBOL(debug_hex_ascii_view); 110 111 static struct debug_view debug_level_view = { 112 "level", 113 &debug_prolog_level_fn, 114 NULL, 115 NULL, 116 &debug_input_level_fn, 117 NULL 118 }; 119 120 static struct debug_view debug_pages_view = { 121 "pages", 122 &debug_prolog_pages_fn, 123 NULL, 124 NULL, 125 &debug_input_pages_fn, 126 NULL 127 }; 128 129 static struct debug_view debug_flush_view = { 130 "flush", 131 NULL, 132 NULL, 133 NULL, 134 &debug_input_flush_fn, 135 NULL 136 }; 137 138 struct debug_view debug_sprintf_view = { 139 "sprintf", 140 NULL, 141 &debug_dflt_header_fn, 142 (debug_format_proc_t *)&debug_sprintf_format_fn, 143 NULL, 144 NULL 145 }; 146 EXPORT_SYMBOL(debug_sprintf_view); 147 148 /* used by dump analysis tools to determine version of debug feature */ 149 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 150 151 /* static globals */ 152 153 static debug_info_t *debug_area_first; 154 static debug_info_t *debug_area_last; 155 static DEFINE_MUTEX(debug_mutex); 156 157 static int initialized; 158 static int debug_critical; 159 160 static const struct file_operations debug_file_ops = { 161 .owner = THIS_MODULE, 162 .read = debug_output, 163 .write = debug_input, 164 .open = debug_open, 165 .release = debug_close, 166 .llseek = no_llseek, 167 }; 168 169 static struct dentry *debug_debugfs_root_entry; 170 171 /* functions */ 172 173 /* 174 * debug_areas_alloc 175 * - Debug areas are implemented as a threedimensonal array: 176 * areas[areanumber][pagenumber][pageoffset] 177 */ 178 179 static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas) 180 { 181 debug_entry_t ***areas; 182 int i, j; 183 184 areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL); 185 if (!areas) 186 goto fail_malloc_areas; 187 for (i = 0; i < nr_areas; i++) { 188 /* GFP_NOWARN to avoid user triggerable WARN, we handle fails */ 189 areas[i] = kmalloc_array(pages_per_area, 190 sizeof(debug_entry_t *), 191 GFP_KERNEL | __GFP_NOWARN); 192 if (!areas[i]) 193 goto fail_malloc_areas2; 194 for (j = 0; j < pages_per_area; j++) { 195 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); 196 if (!areas[i][j]) { 197 for (j--; j >= 0 ; j--) 198 kfree(areas[i][j]); 199 kfree(areas[i]); 200 goto fail_malloc_areas2; 201 } 202 } 203 } 204 return areas; 205 206 fail_malloc_areas2: 207 for (i--; i >= 0; i--) { 208 for (j = 0; j < pages_per_area; j++) 209 kfree(areas[i][j]); 210 kfree(areas[i]); 211 } 212 kfree(areas); 213 fail_malloc_areas: 214 return NULL; 215 } 216 217 /* 218 * debug_info_alloc 219 * - alloc new debug-info 220 */ 221 static debug_info_t *debug_info_alloc(const char *name, int pages_per_area, 222 int nr_areas, int buf_size, int level, 223 int mode) 224 { 225 debug_info_t *rc; 226 227 /* alloc everything */ 228 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); 229 if (!rc) 230 goto fail_malloc_rc; 231 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 232 if (!rc->active_entries) 233 goto fail_malloc_active_entries; 234 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 235 if (!rc->active_pages) 236 goto fail_malloc_active_pages; 237 if ((mode == ALL_AREAS) && (pages_per_area != 0)) { 238 rc->areas = debug_areas_alloc(pages_per_area, nr_areas); 239 if (!rc->areas) 240 goto fail_malloc_areas; 241 } else { 242 rc->areas = NULL; 243 } 244 245 /* initialize members */ 246 spin_lock_init(&rc->lock); 247 rc->pages_per_area = pages_per_area; 248 rc->nr_areas = nr_areas; 249 rc->active_area = 0; 250 rc->level = level; 251 rc->buf_size = buf_size; 252 rc->entry_size = sizeof(debug_entry_t) + buf_size; 253 strlcpy(rc->name, name, sizeof(rc->name)); 254 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); 255 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *)); 256 refcount_set(&(rc->ref_count), 0); 257 258 return rc; 259 260 fail_malloc_areas: 261 kfree(rc->active_pages); 262 fail_malloc_active_pages: 263 kfree(rc->active_entries); 264 fail_malloc_active_entries: 265 kfree(rc); 266 fail_malloc_rc: 267 return NULL; 268 } 269 270 /* 271 * debug_areas_free 272 * - free all debug areas 273 */ 274 static void debug_areas_free(debug_info_t *db_info) 275 { 276 int i, j; 277 278 if (!db_info->areas) 279 return; 280 for (i = 0; i < db_info->nr_areas; i++) { 281 for (j = 0; j < db_info->pages_per_area; j++) 282 kfree(db_info->areas[i][j]); 283 kfree(db_info->areas[i]); 284 } 285 kfree(db_info->areas); 286 db_info->areas = NULL; 287 } 288 289 /* 290 * debug_info_free 291 * - free memory debug-info 292 */ 293 static void debug_info_free(debug_info_t *db_info) 294 { 295 debug_areas_free(db_info); 296 kfree(db_info->active_entries); 297 kfree(db_info->active_pages); 298 kfree(db_info); 299 } 300 301 /* 302 * debug_info_create 303 * - create new debug-info 304 */ 305 306 static debug_info_t *debug_info_create(const char *name, int pages_per_area, 307 int nr_areas, int buf_size, umode_t mode) 308 { 309 debug_info_t *rc; 310 311 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, 312 DEBUG_DEFAULT_LEVEL, ALL_AREAS); 313 if (!rc) 314 goto out; 315 316 rc->mode = mode & ~S_IFMT; 317 refcount_set(&rc->ref_count, 1); 318 out: 319 return rc; 320 } 321 322 /* 323 * debug_info_copy 324 * - copy debug-info 325 */ 326 static debug_info_t *debug_info_copy(debug_info_t *in, int mode) 327 { 328 unsigned long flags; 329 debug_info_t *rc; 330 int i, j; 331 332 /* get a consistent copy of the debug areas */ 333 do { 334 rc = debug_info_alloc(in->name, in->pages_per_area, 335 in->nr_areas, in->buf_size, in->level, mode); 336 spin_lock_irqsave(&in->lock, flags); 337 if (!rc) 338 goto out; 339 /* has something changed in the meantime ? */ 340 if ((rc->pages_per_area == in->pages_per_area) && 341 (rc->nr_areas == in->nr_areas)) { 342 break; 343 } 344 spin_unlock_irqrestore(&in->lock, flags); 345 debug_info_free(rc); 346 } while (1); 347 348 if (mode == NO_AREAS) 349 goto out; 350 351 for (i = 0; i < in->nr_areas; i++) { 352 for (j = 0; j < in->pages_per_area; j++) 353 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE); 354 } 355 out: 356 spin_unlock_irqrestore(&in->lock, flags); 357 return rc; 358 } 359 360 /* 361 * debug_info_get 362 * - increments reference count for debug-info 363 */ 364 static void debug_info_get(debug_info_t *db_info) 365 { 366 if (db_info) 367 refcount_inc(&db_info->ref_count); 368 } 369 370 /* 371 * debug_info_put: 372 * - decreases reference count for debug-info and frees it if necessary 373 */ 374 static void debug_info_put(debug_info_t *db_info) 375 { 376 if (!db_info) 377 return; 378 if (refcount_dec_and_test(&db_info->ref_count)) 379 debug_info_free(db_info); 380 } 381 382 /* 383 * debug_format_entry: 384 * - format one debug entry and return size of formated data 385 */ 386 static int debug_format_entry(file_private_info_t *p_info) 387 { 388 debug_info_t *id_snap = p_info->debug_info_snap; 389 struct debug_view *view = p_info->view; 390 debug_entry_t *act_entry; 391 size_t len = 0; 392 393 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { 394 /* print prolog */ 395 if (view->prolog_proc) 396 len += view->prolog_proc(id_snap, view, p_info->temp_buf); 397 goto out; 398 } 399 if (!id_snap->areas) /* this is true, if we have a prolog only view */ 400 goto out; /* or if 'pages_per_area' is 0 */ 401 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area] 402 [p_info->act_page] + p_info->act_entry); 403 404 if (act_entry->clock == 0LL) 405 goto out; /* empty entry */ 406 if (view->header_proc) 407 len += view->header_proc(id_snap, view, p_info->act_area, 408 act_entry, p_info->temp_buf + len); 409 if (view->format_proc) 410 len += view->format_proc(id_snap, view, p_info->temp_buf + len, 411 DEBUG_DATA(act_entry)); 412 out: 413 return len; 414 } 415 416 /* 417 * debug_next_entry: 418 * - goto next entry in p_info 419 */ 420 static inline int debug_next_entry(file_private_info_t *p_info) 421 { 422 debug_info_t *id; 423 424 id = p_info->debug_info_snap; 425 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { 426 p_info->act_entry = 0; 427 p_info->act_page = 0; 428 goto out; 429 } 430 if (!id->areas) 431 return 1; 432 p_info->act_entry += id->entry_size; 433 /* switch to next page, if we reached the end of the page */ 434 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) { 435 /* next page */ 436 p_info->act_entry = 0; 437 p_info->act_page += 1; 438 if ((p_info->act_page % id->pages_per_area) == 0) { 439 /* next area */ 440 p_info->act_area++; 441 p_info->act_page = 0; 442 } 443 if (p_info->act_area >= id->nr_areas) 444 return 1; 445 } 446 out: 447 return 0; 448 } 449 450 /* 451 * debug_output: 452 * - called for user read() 453 * - copies formated debug entries to the user buffer 454 */ 455 static ssize_t debug_output(struct file *file, /* file descriptor */ 456 char __user *user_buf, /* user buffer */ 457 size_t len, /* length of buffer */ 458 loff_t *offset) /* offset in the file */ 459 { 460 size_t count = 0; 461 size_t entry_offset; 462 file_private_info_t *p_info; 463 464 p_info = (file_private_info_t *) file->private_data; 465 if (*offset != p_info->offset) 466 return -EPIPE; 467 if (p_info->act_area >= p_info->debug_info_snap->nr_areas) 468 return 0; 469 entry_offset = p_info->act_entry_offset; 470 while (count < len) { 471 int formatted_line_residue; 472 int formatted_line_size; 473 int user_buf_residue; 474 size_t copy_size; 475 476 formatted_line_size = debug_format_entry(p_info); 477 formatted_line_residue = formatted_line_size - entry_offset; 478 user_buf_residue = len-count; 479 copy_size = min(user_buf_residue, formatted_line_residue); 480 if (copy_size) { 481 if (copy_to_user(user_buf + count, p_info->temp_buf 482 + entry_offset, copy_size)) 483 return -EFAULT; 484 count += copy_size; 485 entry_offset += copy_size; 486 } 487 if (copy_size == formatted_line_residue) { 488 entry_offset = 0; 489 if (debug_next_entry(p_info)) 490 goto out; 491 } 492 } 493 out: 494 p_info->offset = *offset + count; 495 p_info->act_entry_offset = entry_offset; 496 *offset = p_info->offset; 497 return count; 498 } 499 500 /* 501 * debug_input: 502 * - called for user write() 503 * - calls input function of view 504 */ 505 static ssize_t debug_input(struct file *file, const char __user *user_buf, 506 size_t length, loff_t *offset) 507 { 508 file_private_info_t *p_info; 509 int rc = 0; 510 511 mutex_lock(&debug_mutex); 512 p_info = ((file_private_info_t *) file->private_data); 513 if (p_info->view->input_proc) { 514 rc = p_info->view->input_proc(p_info->debug_info_org, 515 p_info->view, file, user_buf, 516 length, offset); 517 } else { 518 rc = -EPERM; 519 } 520 mutex_unlock(&debug_mutex); 521 return rc; /* number of input characters */ 522 } 523 524 /* 525 * debug_open: 526 * - called for user open() 527 * - copies formated output to private_data area of the file 528 * handle 529 */ 530 static int debug_open(struct inode *inode, struct file *file) 531 { 532 debug_info_t *debug_info, *debug_info_snapshot; 533 file_private_info_t *p_info; 534 int i, rc = 0; 535 536 mutex_lock(&debug_mutex); 537 debug_info = file_inode(file)->i_private; 538 /* find debug view */ 539 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 540 if (!debug_info->views[i]) 541 continue; 542 else if (debug_info->debugfs_entries[i] == file->f_path.dentry) 543 goto found; /* found view ! */ 544 } 545 /* no entry found */ 546 rc = -EINVAL; 547 goto out; 548 549 found: 550 551 /* Make snapshot of current debug areas to get it consistent. */ 552 /* To copy all the areas is only needed, if we have a view which */ 553 /* formats the debug areas. */ 554 555 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc) 556 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS); 557 else 558 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS); 559 560 if (!debug_info_snapshot) { 561 rc = -ENOMEM; 562 goto out; 563 } 564 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL); 565 if (!p_info) { 566 debug_info_free(debug_info_snapshot); 567 rc = -ENOMEM; 568 goto out; 569 } 570 p_info->offset = 0; 571 p_info->debug_info_snap = debug_info_snapshot; 572 p_info->debug_info_org = debug_info; 573 p_info->view = debug_info->views[i]; 574 p_info->act_area = 0; 575 p_info->act_page = 0; 576 p_info->act_entry = DEBUG_PROLOG_ENTRY; 577 p_info->act_entry_offset = 0; 578 file->private_data = p_info; 579 debug_info_get(debug_info); 580 nonseekable_open(inode, file); 581 out: 582 mutex_unlock(&debug_mutex); 583 return rc; 584 } 585 586 /* 587 * debug_close: 588 * - called for user close() 589 * - deletes private_data area of the file handle 590 */ 591 static int debug_close(struct inode *inode, struct file *file) 592 { 593 file_private_info_t *p_info; 594 595 p_info = (file_private_info_t *) file->private_data; 596 if (p_info->debug_info_snap) 597 debug_info_free(p_info->debug_info_snap); 598 debug_info_put(p_info->debug_info_org); 599 kfree(file->private_data); 600 return 0; /* success */ 601 } 602 603 /* Create debugfs entries and add to internal list. */ 604 static void _debug_register(debug_info_t *id) 605 { 606 /* create root directory */ 607 id->debugfs_root_entry = debugfs_create_dir(id->name, 608 debug_debugfs_root_entry); 609 610 /* append new element to linked list */ 611 if (!debug_area_first) { 612 /* first element in list */ 613 debug_area_first = id; 614 id->prev = NULL; 615 } else { 616 /* append element to end of list */ 617 debug_area_last->next = id; 618 id->prev = debug_area_last; 619 } 620 debug_area_last = id; 621 id->next = NULL; 622 623 debug_register_view(id, &debug_level_view); 624 debug_register_view(id, &debug_flush_view); 625 debug_register_view(id, &debug_pages_view); 626 } 627 628 /** 629 * debug_register_mode() - creates and initializes debug area. 630 * 631 * @name: Name of debug log (e.g. used for debugfs entry) 632 * @pages_per_area: Number of pages, which will be allocated per area 633 * @nr_areas: Number of debug areas 634 * @buf_size: Size of data area in each debug entry 635 * @mode: File mode for debugfs files. E.g. S_IRWXUGO 636 * @uid: User ID for debugfs files. Currently only 0 is supported. 637 * @gid: Group ID for debugfs files. Currently only 0 is supported. 638 * 639 * Return: 640 * - Handle for generated debug area 641 * - %NULL if register failed 642 * 643 * Allocates memory for a debug log. 644 * Must not be called within an interrupt handler. 645 */ 646 debug_info_t *debug_register_mode(const char *name, int pages_per_area, 647 int nr_areas, int buf_size, umode_t mode, 648 uid_t uid, gid_t gid) 649 { 650 debug_info_t *rc = NULL; 651 652 /* Since debugfs currently does not support uid/gid other than root, */ 653 /* we do not allow gid/uid != 0 until we get support for that. */ 654 if ((uid != 0) || (gid != 0)) 655 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n"); 656 BUG_ON(!initialized); 657 658 /* create new debug_info */ 659 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 660 if (rc) { 661 mutex_lock(&debug_mutex); 662 _debug_register(rc); 663 mutex_unlock(&debug_mutex); 664 } else { 665 pr_err("Registering debug feature %s failed\n", name); 666 } 667 return rc; 668 } 669 EXPORT_SYMBOL(debug_register_mode); 670 671 /** 672 * debug_register() - creates and initializes debug area with default file mode. 673 * 674 * @name: Name of debug log (e.g. used for debugfs entry) 675 * @pages_per_area: Number of pages, which will be allocated per area 676 * @nr_areas: Number of debug areas 677 * @buf_size: Size of data area in each debug entry 678 * 679 * Return: 680 * - Handle for generated debug area 681 * - %NULL if register failed 682 * 683 * Allocates memory for a debug log. 684 * The debugfs file mode access permissions are read and write for user. 685 * Must not be called within an interrupt handler. 686 */ 687 debug_info_t *debug_register(const char *name, int pages_per_area, 688 int nr_areas, int buf_size) 689 { 690 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 691 S_IRUSR | S_IWUSR, 0, 0); 692 } 693 EXPORT_SYMBOL(debug_register); 694 695 /** 696 * debug_register_static() - registers a static debug area 697 * 698 * @id: Handle for static debug area 699 * @pages_per_area: Number of pages per area 700 * @nr_areas: Number of debug areas 701 * 702 * Register debug_info_t defined using DEFINE_STATIC_DEBUG_INFO. 703 * 704 * Note: This function is called automatically via an initcall generated by 705 * DEFINE_STATIC_DEBUG_INFO. 706 */ 707 void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas) 708 { 709 unsigned long flags; 710 debug_info_t *copy; 711 712 if (!initialized) { 713 pr_err("Tried to register debug feature %s too early\n", 714 id->name); 715 return; 716 } 717 718 copy = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size, 719 id->level, ALL_AREAS); 720 if (!copy) { 721 pr_err("Registering debug feature %s failed\n", id->name); 722 723 /* Clear pointers to prevent tracing into released initdata. */ 724 spin_lock_irqsave(&id->lock, flags); 725 id->areas = NULL; 726 id->active_pages = NULL; 727 id->active_entries = NULL; 728 spin_unlock_irqrestore(&id->lock, flags); 729 730 return; 731 } 732 733 /* Replace static trace area with dynamic copy. */ 734 spin_lock_irqsave(&id->lock, flags); 735 debug_events_append(copy, id); 736 debug_areas_swap(id, copy); 737 spin_unlock_irqrestore(&id->lock, flags); 738 739 /* Clear pointers to initdata and discard copy. */ 740 copy->areas = NULL; 741 copy->active_pages = NULL; 742 copy->active_entries = NULL; 743 debug_info_free(copy); 744 745 mutex_lock(&debug_mutex); 746 _debug_register(id); 747 mutex_unlock(&debug_mutex); 748 } 749 750 /* Remove debugfs entries and remove from internal list. */ 751 static void _debug_unregister(debug_info_t *id) 752 { 753 int i; 754 755 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 756 if (!id->views[i]) 757 continue; 758 debugfs_remove(id->debugfs_entries[i]); 759 } 760 debugfs_remove(id->debugfs_root_entry); 761 if (id == debug_area_first) 762 debug_area_first = id->next; 763 if (id == debug_area_last) 764 debug_area_last = id->prev; 765 if (id->prev) 766 id->prev->next = id->next; 767 if (id->next) 768 id->next->prev = id->prev; 769 } 770 771 /** 772 * debug_unregister() - give back debug area. 773 * 774 * @id: handle for debug log 775 * 776 * Return: 777 * none 778 */ 779 void debug_unregister(debug_info_t *id) 780 { 781 if (!id) 782 return; 783 mutex_lock(&debug_mutex); 784 _debug_unregister(id); 785 mutex_unlock(&debug_mutex); 786 787 debug_info_put(id); 788 } 789 EXPORT_SYMBOL(debug_unregister); 790 791 /* 792 * debug_set_size: 793 * - set area size (number of pages) and number of areas 794 */ 795 static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area) 796 { 797 debug_info_t *new_id; 798 unsigned long flags; 799 800 if (!id || (nr_areas <= 0) || (pages_per_area < 0)) 801 return -EINVAL; 802 803 new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size, 804 id->level, ALL_AREAS); 805 if (!new_id) { 806 pr_info("Allocating memory for %i pages failed\n", 807 pages_per_area); 808 return -ENOMEM; 809 } 810 811 spin_lock_irqsave(&id->lock, flags); 812 debug_events_append(new_id, id); 813 debug_areas_swap(new_id, id); 814 debug_info_free(new_id); 815 spin_unlock_irqrestore(&id->lock, flags); 816 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area); 817 818 return 0; 819 } 820 821 /** 822 * debug_set_level() - Sets new actual debug level if new_level is valid. 823 * 824 * @id: handle for debug log 825 * @new_level: new debug level 826 * 827 * Return: 828 * none 829 */ 830 void debug_set_level(debug_info_t *id, int new_level) 831 { 832 unsigned long flags; 833 834 if (!id) 835 return; 836 837 if (new_level == DEBUG_OFF_LEVEL) { 838 pr_info("%s: switched off\n", id->name); 839 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 840 pr_info("%s: level %i is out of range (%i - %i)\n", 841 id->name, new_level, 0, DEBUG_MAX_LEVEL); 842 return; 843 } 844 845 spin_lock_irqsave(&id->lock, flags); 846 id->level = new_level; 847 spin_unlock_irqrestore(&id->lock, flags); 848 } 849 EXPORT_SYMBOL(debug_set_level); 850 851 /* 852 * proceed_active_entry: 853 * - set active entry to next in the ring buffer 854 */ 855 static inline void proceed_active_entry(debug_info_t *id) 856 { 857 if ((id->active_entries[id->active_area] += id->entry_size) 858 > (PAGE_SIZE - id->entry_size)) { 859 id->active_entries[id->active_area] = 0; 860 id->active_pages[id->active_area] = 861 (id->active_pages[id->active_area] + 1) % 862 id->pages_per_area; 863 } 864 } 865 866 /* 867 * proceed_active_area: 868 * - set active area to next in the ring buffer 869 */ 870 static inline void proceed_active_area(debug_info_t *id) 871 { 872 id->active_area++; 873 id->active_area = id->active_area % id->nr_areas; 874 } 875 876 /* 877 * get_active_entry: 878 */ 879 static inline debug_entry_t *get_active_entry(debug_info_t *id) 880 { 881 return (debug_entry_t *) (((char *) id->areas[id->active_area] 882 [id->active_pages[id->active_area]]) + 883 id->active_entries[id->active_area]); 884 } 885 886 /* Swap debug areas of a and b. */ 887 static void debug_areas_swap(debug_info_t *a, debug_info_t *b) 888 { 889 swap(a->nr_areas, b->nr_areas); 890 swap(a->pages_per_area, b->pages_per_area); 891 swap(a->areas, b->areas); 892 swap(a->active_area, b->active_area); 893 swap(a->active_pages, b->active_pages); 894 swap(a->active_entries, b->active_entries); 895 } 896 897 /* Append all debug events in active area from source to destination log. */ 898 static void debug_events_append(debug_info_t *dest, debug_info_t *src) 899 { 900 debug_entry_t *from, *to, *last; 901 902 if (!src->areas || !dest->areas) 903 return; 904 905 /* Loop over all entries in src, starting with oldest. */ 906 from = get_active_entry(src); 907 last = from; 908 do { 909 if (from->clock != 0LL) { 910 to = get_active_entry(dest); 911 memset(to, 0, dest->entry_size); 912 memcpy(to, from, min(src->entry_size, 913 dest->entry_size)); 914 proceed_active_entry(dest); 915 } 916 917 proceed_active_entry(src); 918 from = get_active_entry(src); 919 } while (from != last); 920 } 921 922 /* 923 * debug_finish_entry: 924 * - set timestamp, caller address, cpu number etc. 925 */ 926 927 static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active, 928 int level, int exception) 929 { 930 unsigned long timestamp; 931 union tod_clock clk; 932 933 store_tod_clock_ext(&clk); 934 timestamp = clk.us; 935 timestamp -= TOD_UNIX_EPOCH >> 12; 936 active->clock = timestamp; 937 active->cpu = smp_processor_id(); 938 active->caller = __builtin_return_address(0); 939 active->exception = exception; 940 active->level = level; 941 proceed_active_entry(id); 942 if (exception) 943 proceed_active_area(id); 944 } 945 946 static int debug_stoppable = 1; 947 static int debug_active = 1; 948 949 #define CTL_S390DBF_STOPPABLE 5678 950 #define CTL_S390DBF_ACTIVE 5679 951 952 /* 953 * proc handler for the running debug_active sysctl 954 * always allow read, allow write only if debug_stoppable is set or 955 * if debug_active is already off 956 */ 957 static int s390dbf_procactive(struct ctl_table *table, int write, 958 void *buffer, size_t *lenp, loff_t *ppos) 959 { 960 if (!write || debug_stoppable || !debug_active) 961 return proc_dointvec(table, write, buffer, lenp, ppos); 962 else 963 return 0; 964 } 965 966 static struct ctl_table s390dbf_table[] = { 967 { 968 .procname = "debug_stoppable", 969 .data = &debug_stoppable, 970 .maxlen = sizeof(int), 971 .mode = S_IRUGO | S_IWUSR, 972 .proc_handler = proc_dointvec, 973 }, 974 { 975 .procname = "debug_active", 976 .data = &debug_active, 977 .maxlen = sizeof(int), 978 .mode = S_IRUGO | S_IWUSR, 979 .proc_handler = s390dbf_procactive, 980 }, 981 { } 982 }; 983 984 static struct ctl_table s390dbf_dir_table[] = { 985 { 986 .procname = "s390dbf", 987 .maxlen = 0, 988 .mode = S_IRUGO | S_IXUGO, 989 .child = s390dbf_table, 990 }, 991 { } 992 }; 993 994 static struct ctl_table_header *s390dbf_sysctl_header; 995 996 /** 997 * debug_stop_all() - stops the debug feature if stopping is allowed. 998 * 999 * Return: 1000 * - none 1001 * 1002 * Currently used in case of a kernel oops. 1003 */ 1004 void debug_stop_all(void) 1005 { 1006 if (debug_stoppable) 1007 debug_active = 0; 1008 } 1009 EXPORT_SYMBOL(debug_stop_all); 1010 1011 /** 1012 * debug_set_critical() - event/exception functions try lock instead of spin. 1013 * 1014 * Return: 1015 * - none 1016 * 1017 * Currently used in case of stopping all CPUs but the current one. 1018 * Once in this state, functions to write a debug entry for an 1019 * event or exception no longer spin on the debug area lock, 1020 * but only try to get it and fail if they do not get the lock. 1021 */ 1022 void debug_set_critical(void) 1023 { 1024 debug_critical = 1; 1025 } 1026 1027 /* 1028 * debug_event_common: 1029 * - write debug entry with given size 1030 */ 1031 debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf, 1032 int len) 1033 { 1034 debug_entry_t *active; 1035 unsigned long flags; 1036 1037 if (!debug_active || !id->areas) 1038 return NULL; 1039 if (debug_critical) { 1040 if (!spin_trylock_irqsave(&id->lock, flags)) 1041 return NULL; 1042 } else { 1043 spin_lock_irqsave(&id->lock, flags); 1044 } 1045 do { 1046 active = get_active_entry(id); 1047 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1048 if (len < id->buf_size) 1049 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1050 debug_finish_entry(id, active, level, 0); 1051 len -= id->buf_size; 1052 buf += id->buf_size; 1053 } while (len > 0); 1054 1055 spin_unlock_irqrestore(&id->lock, flags); 1056 return active; 1057 } 1058 EXPORT_SYMBOL(debug_event_common); 1059 1060 /* 1061 * debug_exception_common: 1062 * - write debug entry with given size and switch to next debug area 1063 */ 1064 debug_entry_t *debug_exception_common(debug_info_t *id, int level, 1065 const void *buf, int len) 1066 { 1067 debug_entry_t *active; 1068 unsigned long flags; 1069 1070 if (!debug_active || !id->areas) 1071 return NULL; 1072 if (debug_critical) { 1073 if (!spin_trylock_irqsave(&id->lock, flags)) 1074 return NULL; 1075 } else { 1076 spin_lock_irqsave(&id->lock, flags); 1077 } 1078 do { 1079 active = get_active_entry(id); 1080 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1081 if (len < id->buf_size) 1082 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1083 debug_finish_entry(id, active, level, len <= id->buf_size); 1084 len -= id->buf_size; 1085 buf += id->buf_size; 1086 } while (len > 0); 1087 1088 spin_unlock_irqrestore(&id->lock, flags); 1089 return active; 1090 } 1091 EXPORT_SYMBOL(debug_exception_common); 1092 1093 /* 1094 * counts arguments in format string for sprintf view 1095 */ 1096 static inline int debug_count_numargs(char *string) 1097 { 1098 int numargs = 0; 1099 1100 while (*string) { 1101 if (*string++ == '%') 1102 numargs++; 1103 } 1104 return numargs; 1105 } 1106 1107 /* 1108 * debug_sprintf_event: 1109 */ 1110 debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 1111 { 1112 debug_sprintf_entry_t *curr_event; 1113 debug_entry_t *active; 1114 unsigned long flags; 1115 int numargs, idx; 1116 va_list ap; 1117 1118 if (!debug_active || !id->areas) 1119 return NULL; 1120 numargs = debug_count_numargs(string); 1121 1122 if (debug_critical) { 1123 if (!spin_trylock_irqsave(&id->lock, flags)) 1124 return NULL; 1125 } else { 1126 spin_lock_irqsave(&id->lock, flags); 1127 } 1128 active = get_active_entry(id); 1129 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active); 1130 va_start(ap, string); 1131 curr_event->string = string; 1132 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1133 curr_event->args[idx] = va_arg(ap, long); 1134 va_end(ap); 1135 debug_finish_entry(id, active, level, 0); 1136 spin_unlock_irqrestore(&id->lock, flags); 1137 1138 return active; 1139 } 1140 EXPORT_SYMBOL(__debug_sprintf_event); 1141 1142 /* 1143 * debug_sprintf_exception: 1144 */ 1145 debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 1146 { 1147 debug_sprintf_entry_t *curr_event; 1148 debug_entry_t *active; 1149 unsigned long flags; 1150 int numargs, idx; 1151 va_list ap; 1152 1153 if (!debug_active || !id->areas) 1154 return NULL; 1155 1156 numargs = debug_count_numargs(string); 1157 1158 if (debug_critical) { 1159 if (!spin_trylock_irqsave(&id->lock, flags)) 1160 return NULL; 1161 } else { 1162 spin_lock_irqsave(&id->lock, flags); 1163 } 1164 active = get_active_entry(id); 1165 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active); 1166 va_start(ap, string); 1167 curr_event->string = string; 1168 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1169 curr_event->args[idx] = va_arg(ap, long); 1170 va_end(ap); 1171 debug_finish_entry(id, active, level, 1); 1172 spin_unlock_irqrestore(&id->lock, flags); 1173 1174 return active; 1175 } 1176 EXPORT_SYMBOL(__debug_sprintf_exception); 1177 1178 /** 1179 * debug_register_view() - registers new debug view and creates debugfs 1180 * dir entry 1181 * 1182 * @id: handle for debug log 1183 * @view: pointer to debug view struct 1184 * 1185 * Return: 1186 * - 0 : ok 1187 * - < 0: Error 1188 */ 1189 int debug_register_view(debug_info_t *id, struct debug_view *view) 1190 { 1191 unsigned long flags; 1192 struct dentry *pde; 1193 umode_t mode; 1194 int rc = 0; 1195 int i; 1196 1197 if (!id) 1198 goto out; 1199 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1200 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1201 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1202 if (!view->input_proc) 1203 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1204 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1205 id, &debug_file_ops); 1206 spin_lock_irqsave(&id->lock, flags); 1207 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1208 if (!id->views[i]) 1209 break; 1210 } 1211 if (i == DEBUG_MAX_VIEWS) { 1212 rc = -1; 1213 } else { 1214 id->views[i] = view; 1215 id->debugfs_entries[i] = pde; 1216 } 1217 spin_unlock_irqrestore(&id->lock, flags); 1218 if (rc) { 1219 pr_err("Registering view %s/%s would exceed the maximum " 1220 "number of views %i\n", id->name, view->name, i); 1221 debugfs_remove(pde); 1222 } 1223 out: 1224 return rc; 1225 } 1226 EXPORT_SYMBOL(debug_register_view); 1227 1228 /** 1229 * debug_unregister_view() - unregisters debug view and removes debugfs 1230 * dir entry 1231 * 1232 * @id: handle for debug log 1233 * @view: pointer to debug view struct 1234 * 1235 * Return: 1236 * - 0 : ok 1237 * - < 0: Error 1238 */ 1239 int debug_unregister_view(debug_info_t *id, struct debug_view *view) 1240 { 1241 struct dentry *dentry = NULL; 1242 unsigned long flags; 1243 int i, rc = 0; 1244 1245 if (!id) 1246 goto out; 1247 spin_lock_irqsave(&id->lock, flags); 1248 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1249 if (id->views[i] == view) 1250 break; 1251 } 1252 if (i == DEBUG_MAX_VIEWS) { 1253 rc = -1; 1254 } else { 1255 dentry = id->debugfs_entries[i]; 1256 id->views[i] = NULL; 1257 id->debugfs_entries[i] = NULL; 1258 } 1259 spin_unlock_irqrestore(&id->lock, flags); 1260 debugfs_remove(dentry); 1261 out: 1262 return rc; 1263 } 1264 EXPORT_SYMBOL(debug_unregister_view); 1265 1266 static inline char *debug_get_user_string(const char __user *user_buf, 1267 size_t user_len) 1268 { 1269 char *buffer; 1270 1271 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1272 if (!buffer) 1273 return ERR_PTR(-ENOMEM); 1274 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1275 kfree(buffer); 1276 return ERR_PTR(-EFAULT); 1277 } 1278 /* got the string, now strip linefeed. */ 1279 if (buffer[user_len - 1] == '\n') 1280 buffer[user_len - 1] = 0; 1281 else 1282 buffer[user_len] = 0; 1283 return buffer; 1284 } 1285 1286 static inline int debug_get_uint(char *buf) 1287 { 1288 int rc; 1289 1290 buf = skip_spaces(buf); 1291 rc = simple_strtoul(buf, &buf, 10); 1292 if (*buf) 1293 rc = -EINVAL; 1294 return rc; 1295 } 1296 1297 /* 1298 * functions for debug-views 1299 *********************************** 1300 */ 1301 1302 /* 1303 * prints out actual debug level 1304 */ 1305 1306 static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view, 1307 char *out_buf) 1308 { 1309 return sprintf(out_buf, "%i\n", id->pages_per_area); 1310 } 1311 1312 /* 1313 * reads new size (number of pages per debug area) 1314 */ 1315 1316 static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, 1317 struct file *file, const char __user *user_buf, 1318 size_t user_len, loff_t *offset) 1319 { 1320 int rc, new_pages; 1321 char *str; 1322 1323 if (user_len > 0x10000) 1324 user_len = 0x10000; 1325 if (*offset != 0) { 1326 rc = -EPIPE; 1327 goto out; 1328 } 1329 str = debug_get_user_string(user_buf, user_len); 1330 if (IS_ERR(str)) { 1331 rc = PTR_ERR(str); 1332 goto out; 1333 } 1334 new_pages = debug_get_uint(str); 1335 if (new_pages < 0) { 1336 rc = -EINVAL; 1337 goto free_str; 1338 } 1339 rc = debug_set_size(id, id->nr_areas, new_pages); 1340 if (rc != 0) { 1341 rc = -EINVAL; 1342 goto free_str; 1343 } 1344 rc = user_len; 1345 free_str: 1346 kfree(str); 1347 out: 1348 *offset += user_len; 1349 return rc; /* number of input characters */ 1350 } 1351 1352 /* 1353 * prints out actual debug level 1354 */ 1355 static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view, 1356 char *out_buf) 1357 { 1358 int rc = 0; 1359 1360 if (id->level == DEBUG_OFF_LEVEL) 1361 rc = sprintf(out_buf, "-\n"); 1362 else 1363 rc = sprintf(out_buf, "%i\n", id->level); 1364 return rc; 1365 } 1366 1367 /* 1368 * reads new debug level 1369 */ 1370 static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 1371 struct file *file, const char __user *user_buf, 1372 size_t user_len, loff_t *offset) 1373 { 1374 int rc, new_level; 1375 char *str; 1376 1377 if (user_len > 0x10000) 1378 user_len = 0x10000; 1379 if (*offset != 0) { 1380 rc = -EPIPE; 1381 goto out; 1382 } 1383 str = debug_get_user_string(user_buf, user_len); 1384 if (IS_ERR(str)) { 1385 rc = PTR_ERR(str); 1386 goto out; 1387 } 1388 if (str[0] == '-') { 1389 debug_set_level(id, DEBUG_OFF_LEVEL); 1390 rc = user_len; 1391 goto free_str; 1392 } else { 1393 new_level = debug_get_uint(str); 1394 } 1395 if (new_level < 0) { 1396 pr_warn("%s is not a valid level for a debug feature\n", str); 1397 rc = -EINVAL; 1398 } else { 1399 debug_set_level(id, new_level); 1400 rc = user_len; 1401 } 1402 free_str: 1403 kfree(str); 1404 out: 1405 *offset += user_len; 1406 return rc; /* number of input characters */ 1407 } 1408 1409 /* 1410 * flushes debug areas 1411 */ 1412 static void debug_flush(debug_info_t *id, int area) 1413 { 1414 unsigned long flags; 1415 int i, j; 1416 1417 if (!id || !id->areas) 1418 return; 1419 spin_lock_irqsave(&id->lock, flags); 1420 if (area == DEBUG_FLUSH_ALL) { 1421 id->active_area = 0; 1422 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1423 for (i = 0; i < id->nr_areas; i++) { 1424 id->active_pages[i] = 0; 1425 for (j = 0; j < id->pages_per_area; j++) 1426 memset(id->areas[i][j], 0, PAGE_SIZE); 1427 } 1428 } else if (area >= 0 && area < id->nr_areas) { 1429 id->active_entries[area] = 0; 1430 id->active_pages[area] = 0; 1431 for (i = 0; i < id->pages_per_area; i++) 1432 memset(id->areas[area][i], 0, PAGE_SIZE); 1433 } 1434 spin_unlock_irqrestore(&id->lock, flags); 1435 } 1436 1437 /* 1438 * view function: flushes debug areas 1439 */ 1440 static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 1441 struct file *file, const char __user *user_buf, 1442 size_t user_len, loff_t *offset) 1443 { 1444 char input_buf[1]; 1445 int rc = user_len; 1446 1447 if (user_len > 0x10000) 1448 user_len = 0x10000; 1449 if (*offset != 0) { 1450 rc = -EPIPE; 1451 goto out; 1452 } 1453 if (copy_from_user(input_buf, user_buf, 1)) { 1454 rc = -EFAULT; 1455 goto out; 1456 } 1457 if (input_buf[0] == '-') { 1458 debug_flush(id, DEBUG_FLUSH_ALL); 1459 goto out; 1460 } 1461 if (isdigit(input_buf[0])) { 1462 int area = ((int) input_buf[0] - (int) '0'); 1463 1464 debug_flush(id, area); 1465 goto out; 1466 } 1467 1468 pr_info("Flushing debug data failed because %c is not a valid " 1469 "area\n", input_buf[0]); 1470 1471 out: 1472 *offset += user_len; 1473 return rc; /* number of input characters */ 1474 } 1475 1476 /* 1477 * prints debug data in hex/ascii format 1478 */ 1479 static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 1480 char *out_buf, const char *in_buf) 1481 { 1482 int i, rc = 0; 1483 1484 for (i = 0; i < id->buf_size; i++) 1485 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]); 1486 rc += sprintf(out_buf + rc, "| "); 1487 for (i = 0; i < id->buf_size; i++) { 1488 unsigned char c = in_buf[i]; 1489 1490 if (isascii(c) && isprint(c)) 1491 rc += sprintf(out_buf + rc, "%c", c); 1492 else 1493 rc += sprintf(out_buf + rc, "."); 1494 } 1495 rc += sprintf(out_buf + rc, "\n"); 1496 return rc; 1497 } 1498 1499 /* 1500 * prints header for debug entry 1501 */ 1502 int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view, 1503 int area, debug_entry_t *entry, char *out_buf) 1504 { 1505 unsigned long sec, usec; 1506 unsigned long caller; 1507 unsigned int level; 1508 char *except_str; 1509 int rc = 0; 1510 1511 level = entry->level; 1512 sec = entry->clock; 1513 usec = do_div(sec, USEC_PER_SEC); 1514 1515 if (entry->exception) 1516 except_str = "*"; 1517 else 1518 except_str = "-"; 1519 caller = (unsigned long) entry->caller; 1520 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %04u %px ", 1521 area, sec, usec, level, except_str, 1522 entry->cpu, (void *)caller); 1523 return rc; 1524 } 1525 EXPORT_SYMBOL(debug_dflt_header_fn); 1526 1527 /* 1528 * prints debug data sprintf-formated: 1529 * debug_sprinf_event/exception calls must be used together with this view 1530 */ 1531 1532 #define DEBUG_SPRINTF_MAX_ARGS 10 1533 1534 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 1535 char *out_buf, debug_sprintf_entry_t *curr_event) 1536 { 1537 int num_longs, num_used_args = 0, i, rc = 0; 1538 int index[DEBUG_SPRINTF_MAX_ARGS]; 1539 1540 /* count of longs fit into one entry */ 1541 num_longs = id->buf_size / sizeof(long); 1542 1543 if (num_longs < 1) 1544 goto out; /* bufsize of entry too small */ 1545 if (num_longs == 1) { 1546 /* no args, we use only the string */ 1547 strcpy(out_buf, curr_event->string); 1548 rc = strlen(curr_event->string); 1549 goto out; 1550 } 1551 1552 /* number of arguments used for sprintf (without the format string) */ 1553 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1554 1555 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1556 1557 for (i = 0; i < num_used_args; i++) 1558 index[i] = i; 1559 1560 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1561 curr_event->args[index[1]], curr_event->args[index[2]], 1562 curr_event->args[index[3]], curr_event->args[index[4]], 1563 curr_event->args[index[5]], curr_event->args[index[6]], 1564 curr_event->args[index[7]], curr_event->args[index[8]], 1565 curr_event->args[index[9]]); 1566 out: 1567 return rc; 1568 } 1569 1570 /* 1571 * debug_init: 1572 * - is called exactly once to initialize the debug feature 1573 */ 1574 static int __init debug_init(void) 1575 { 1576 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1577 mutex_lock(&debug_mutex); 1578 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1579 initialized = 1; 1580 mutex_unlock(&debug_mutex); 1581 return 0; 1582 } 1583 postcore_initcall(debug_init); 1584