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