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 .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 strscpy(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_header *s390dbf_sysctl_header; 985 986 /** 987 * debug_stop_all() - stops the debug feature if stopping is allowed. 988 * 989 * Return: 990 * - none 991 * 992 * Currently used in case of a kernel oops. 993 */ 994 void debug_stop_all(void) 995 { 996 if (debug_stoppable) 997 debug_active = 0; 998 } 999 EXPORT_SYMBOL(debug_stop_all); 1000 1001 /** 1002 * debug_set_critical() - event/exception functions try lock instead of spin. 1003 * 1004 * Return: 1005 * - none 1006 * 1007 * Currently used in case of stopping all CPUs but the current one. 1008 * Once in this state, functions to write a debug entry for an 1009 * event or exception no longer spin on the debug area lock, 1010 * but only try to get it and fail if they do not get the lock. 1011 */ 1012 void debug_set_critical(void) 1013 { 1014 debug_critical = 1; 1015 } 1016 1017 /* 1018 * debug_event_common: 1019 * - write debug entry with given size 1020 */ 1021 debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf, 1022 int len) 1023 { 1024 debug_entry_t *active; 1025 unsigned long flags; 1026 1027 if (!debug_active || !id->areas) 1028 return NULL; 1029 if (debug_critical) { 1030 if (!spin_trylock_irqsave(&id->lock, flags)) 1031 return NULL; 1032 } else { 1033 spin_lock_irqsave(&id->lock, flags); 1034 } 1035 do { 1036 active = get_active_entry(id); 1037 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1038 if (len < id->buf_size) 1039 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1040 debug_finish_entry(id, active, level, 0); 1041 len -= id->buf_size; 1042 buf += id->buf_size; 1043 } while (len > 0); 1044 1045 spin_unlock_irqrestore(&id->lock, flags); 1046 return active; 1047 } 1048 EXPORT_SYMBOL(debug_event_common); 1049 1050 /* 1051 * debug_exception_common: 1052 * - write debug entry with given size and switch to next debug area 1053 */ 1054 debug_entry_t *debug_exception_common(debug_info_t *id, int level, 1055 const void *buf, int len) 1056 { 1057 debug_entry_t *active; 1058 unsigned long flags; 1059 1060 if (!debug_active || !id->areas) 1061 return NULL; 1062 if (debug_critical) { 1063 if (!spin_trylock_irqsave(&id->lock, flags)) 1064 return NULL; 1065 } else { 1066 spin_lock_irqsave(&id->lock, flags); 1067 } 1068 do { 1069 active = get_active_entry(id); 1070 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1071 if (len < id->buf_size) 1072 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1073 debug_finish_entry(id, active, level, len <= id->buf_size); 1074 len -= id->buf_size; 1075 buf += id->buf_size; 1076 } while (len > 0); 1077 1078 spin_unlock_irqrestore(&id->lock, flags); 1079 return active; 1080 } 1081 EXPORT_SYMBOL(debug_exception_common); 1082 1083 /* 1084 * counts arguments in format string for sprintf view 1085 */ 1086 static inline int debug_count_numargs(char *string) 1087 { 1088 int numargs = 0; 1089 1090 while (*string) { 1091 if (*string++ == '%') 1092 numargs++; 1093 } 1094 return numargs; 1095 } 1096 1097 /* 1098 * debug_sprintf_event: 1099 */ 1100 debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 1101 { 1102 debug_sprintf_entry_t *curr_event; 1103 debug_entry_t *active; 1104 unsigned long flags; 1105 int numargs, idx; 1106 va_list ap; 1107 1108 if (!debug_active || !id->areas) 1109 return NULL; 1110 numargs = debug_count_numargs(string); 1111 1112 if (debug_critical) { 1113 if (!spin_trylock_irqsave(&id->lock, flags)) 1114 return NULL; 1115 } else { 1116 spin_lock_irqsave(&id->lock, flags); 1117 } 1118 active = get_active_entry(id); 1119 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active); 1120 va_start(ap, string); 1121 curr_event->string = string; 1122 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1123 curr_event->args[idx] = va_arg(ap, long); 1124 va_end(ap); 1125 debug_finish_entry(id, active, level, 0); 1126 spin_unlock_irqrestore(&id->lock, flags); 1127 1128 return active; 1129 } 1130 EXPORT_SYMBOL(__debug_sprintf_event); 1131 1132 /* 1133 * debug_sprintf_exception: 1134 */ 1135 debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 1136 { 1137 debug_sprintf_entry_t *curr_event; 1138 debug_entry_t *active; 1139 unsigned long flags; 1140 int numargs, idx; 1141 va_list ap; 1142 1143 if (!debug_active || !id->areas) 1144 return NULL; 1145 1146 numargs = debug_count_numargs(string); 1147 1148 if (debug_critical) { 1149 if (!spin_trylock_irqsave(&id->lock, flags)) 1150 return NULL; 1151 } else { 1152 spin_lock_irqsave(&id->lock, flags); 1153 } 1154 active = get_active_entry(id); 1155 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active); 1156 va_start(ap, string); 1157 curr_event->string = string; 1158 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1159 curr_event->args[idx] = va_arg(ap, long); 1160 va_end(ap); 1161 debug_finish_entry(id, active, level, 1); 1162 spin_unlock_irqrestore(&id->lock, flags); 1163 1164 return active; 1165 } 1166 EXPORT_SYMBOL(__debug_sprintf_exception); 1167 1168 /** 1169 * debug_register_view() - registers new debug view and creates debugfs 1170 * dir entry 1171 * 1172 * @id: handle for debug log 1173 * @view: pointer to debug view struct 1174 * 1175 * Return: 1176 * - 0 : ok 1177 * - < 0: Error 1178 */ 1179 int debug_register_view(debug_info_t *id, struct debug_view *view) 1180 { 1181 unsigned long flags; 1182 struct dentry *pde; 1183 umode_t mode; 1184 int rc = 0; 1185 int i; 1186 1187 if (!id) 1188 goto out; 1189 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1190 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1191 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1192 if (!view->input_proc) 1193 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1194 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1195 id, &debug_file_ops); 1196 spin_lock_irqsave(&id->lock, flags); 1197 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1198 if (!id->views[i]) 1199 break; 1200 } 1201 if (i == DEBUG_MAX_VIEWS) { 1202 rc = -1; 1203 } else { 1204 id->views[i] = view; 1205 id->debugfs_entries[i] = pde; 1206 } 1207 spin_unlock_irqrestore(&id->lock, flags); 1208 if (rc) { 1209 pr_err("Registering view %s/%s would exceed the maximum " 1210 "number of views %i\n", id->name, view->name, i); 1211 debugfs_remove(pde); 1212 } 1213 out: 1214 return rc; 1215 } 1216 EXPORT_SYMBOL(debug_register_view); 1217 1218 /** 1219 * debug_unregister_view() - unregisters debug view and removes debugfs 1220 * dir entry 1221 * 1222 * @id: handle for debug log 1223 * @view: pointer to debug view struct 1224 * 1225 * Return: 1226 * - 0 : ok 1227 * - < 0: Error 1228 */ 1229 int debug_unregister_view(debug_info_t *id, struct debug_view *view) 1230 { 1231 struct dentry *dentry = NULL; 1232 unsigned long flags; 1233 int i, rc = 0; 1234 1235 if (!id) 1236 goto out; 1237 spin_lock_irqsave(&id->lock, flags); 1238 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1239 if (id->views[i] == view) 1240 break; 1241 } 1242 if (i == DEBUG_MAX_VIEWS) { 1243 rc = -1; 1244 } else { 1245 dentry = id->debugfs_entries[i]; 1246 id->views[i] = NULL; 1247 id->debugfs_entries[i] = NULL; 1248 } 1249 spin_unlock_irqrestore(&id->lock, flags); 1250 debugfs_remove(dentry); 1251 out: 1252 return rc; 1253 } 1254 EXPORT_SYMBOL(debug_unregister_view); 1255 1256 static inline char *debug_get_user_string(const char __user *user_buf, 1257 size_t user_len) 1258 { 1259 char *buffer; 1260 1261 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1262 if (!buffer) 1263 return ERR_PTR(-ENOMEM); 1264 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1265 kfree(buffer); 1266 return ERR_PTR(-EFAULT); 1267 } 1268 /* got the string, now strip linefeed. */ 1269 if (buffer[user_len - 1] == '\n') 1270 buffer[user_len - 1] = 0; 1271 else 1272 buffer[user_len] = 0; 1273 return buffer; 1274 } 1275 1276 static inline int debug_get_uint(char *buf) 1277 { 1278 int rc; 1279 1280 buf = skip_spaces(buf); 1281 rc = simple_strtoul(buf, &buf, 10); 1282 if (*buf) 1283 rc = -EINVAL; 1284 return rc; 1285 } 1286 1287 /* 1288 * functions for debug-views 1289 *********************************** 1290 */ 1291 1292 /* 1293 * prints out actual debug level 1294 */ 1295 1296 static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view, 1297 char *out_buf) 1298 { 1299 return sprintf(out_buf, "%i\n", id->pages_per_area); 1300 } 1301 1302 /* 1303 * reads new size (number of pages per debug area) 1304 */ 1305 1306 static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, 1307 struct file *file, const char __user *user_buf, 1308 size_t user_len, loff_t *offset) 1309 { 1310 int rc, new_pages; 1311 char *str; 1312 1313 if (user_len > 0x10000) 1314 user_len = 0x10000; 1315 if (*offset != 0) { 1316 rc = -EPIPE; 1317 goto out; 1318 } 1319 str = debug_get_user_string(user_buf, user_len); 1320 if (IS_ERR(str)) { 1321 rc = PTR_ERR(str); 1322 goto out; 1323 } 1324 new_pages = debug_get_uint(str); 1325 if (new_pages < 0) { 1326 rc = -EINVAL; 1327 goto free_str; 1328 } 1329 rc = debug_set_size(id, id->nr_areas, new_pages); 1330 if (rc != 0) { 1331 rc = -EINVAL; 1332 goto free_str; 1333 } 1334 rc = user_len; 1335 free_str: 1336 kfree(str); 1337 out: 1338 *offset += user_len; 1339 return rc; /* number of input characters */ 1340 } 1341 1342 /* 1343 * prints out actual debug level 1344 */ 1345 static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view, 1346 char *out_buf) 1347 { 1348 int rc = 0; 1349 1350 if (id->level == DEBUG_OFF_LEVEL) 1351 rc = sprintf(out_buf, "-\n"); 1352 else 1353 rc = sprintf(out_buf, "%i\n", id->level); 1354 return rc; 1355 } 1356 1357 /* 1358 * reads new debug level 1359 */ 1360 static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 1361 struct file *file, const char __user *user_buf, 1362 size_t user_len, loff_t *offset) 1363 { 1364 int rc, new_level; 1365 char *str; 1366 1367 if (user_len > 0x10000) 1368 user_len = 0x10000; 1369 if (*offset != 0) { 1370 rc = -EPIPE; 1371 goto out; 1372 } 1373 str = debug_get_user_string(user_buf, user_len); 1374 if (IS_ERR(str)) { 1375 rc = PTR_ERR(str); 1376 goto out; 1377 } 1378 if (str[0] == '-') { 1379 debug_set_level(id, DEBUG_OFF_LEVEL); 1380 rc = user_len; 1381 goto free_str; 1382 } else { 1383 new_level = debug_get_uint(str); 1384 } 1385 if (new_level < 0) { 1386 pr_warn("%s is not a valid level for a debug feature\n", str); 1387 rc = -EINVAL; 1388 } else { 1389 debug_set_level(id, new_level); 1390 rc = user_len; 1391 } 1392 free_str: 1393 kfree(str); 1394 out: 1395 *offset += user_len; 1396 return rc; /* number of input characters */ 1397 } 1398 1399 /* 1400 * flushes debug areas 1401 */ 1402 static void debug_flush(debug_info_t *id, int area) 1403 { 1404 unsigned long flags; 1405 int i, j; 1406 1407 if (!id || !id->areas) 1408 return; 1409 spin_lock_irqsave(&id->lock, flags); 1410 if (area == DEBUG_FLUSH_ALL) { 1411 id->active_area = 0; 1412 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1413 for (i = 0; i < id->nr_areas; i++) { 1414 id->active_pages[i] = 0; 1415 for (j = 0; j < id->pages_per_area; j++) 1416 memset(id->areas[i][j], 0, PAGE_SIZE); 1417 } 1418 } else if (area >= 0 && area < id->nr_areas) { 1419 id->active_entries[area] = 0; 1420 id->active_pages[area] = 0; 1421 for (i = 0; i < id->pages_per_area; i++) 1422 memset(id->areas[area][i], 0, PAGE_SIZE); 1423 } 1424 spin_unlock_irqrestore(&id->lock, flags); 1425 } 1426 1427 /* 1428 * view function: flushes debug areas 1429 */ 1430 static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 1431 struct file *file, const char __user *user_buf, 1432 size_t user_len, loff_t *offset) 1433 { 1434 char input_buf[1]; 1435 int rc = user_len; 1436 1437 if (user_len > 0x10000) 1438 user_len = 0x10000; 1439 if (*offset != 0) { 1440 rc = -EPIPE; 1441 goto out; 1442 } 1443 if (copy_from_user(input_buf, user_buf, 1)) { 1444 rc = -EFAULT; 1445 goto out; 1446 } 1447 if (input_buf[0] == '-') { 1448 debug_flush(id, DEBUG_FLUSH_ALL); 1449 goto out; 1450 } 1451 if (isdigit(input_buf[0])) { 1452 int area = ((int) input_buf[0] - (int) '0'); 1453 1454 debug_flush(id, area); 1455 goto out; 1456 } 1457 1458 pr_info("Flushing debug data failed because %c is not a valid " 1459 "area\n", input_buf[0]); 1460 1461 out: 1462 *offset += user_len; 1463 return rc; /* number of input characters */ 1464 } 1465 1466 /* 1467 * prints debug data in hex/ascii format 1468 */ 1469 static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 1470 char *out_buf, const char *in_buf) 1471 { 1472 int i, rc = 0; 1473 1474 for (i = 0; i < id->buf_size; i++) 1475 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]); 1476 rc += sprintf(out_buf + rc, "| "); 1477 for (i = 0; i < id->buf_size; i++) { 1478 unsigned char c = in_buf[i]; 1479 1480 if (isascii(c) && isprint(c)) 1481 rc += sprintf(out_buf + rc, "%c", c); 1482 else 1483 rc += sprintf(out_buf + rc, "."); 1484 } 1485 rc += sprintf(out_buf + rc, "\n"); 1486 return rc; 1487 } 1488 1489 /* 1490 * prints header for debug entry 1491 */ 1492 int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view, 1493 int area, debug_entry_t *entry, char *out_buf) 1494 { 1495 unsigned long sec, usec; 1496 unsigned long caller; 1497 unsigned int level; 1498 char *except_str; 1499 int rc = 0; 1500 1501 level = entry->level; 1502 sec = entry->clock; 1503 usec = do_div(sec, USEC_PER_SEC); 1504 1505 if (entry->exception) 1506 except_str = "*"; 1507 else 1508 except_str = "-"; 1509 caller = (unsigned long) entry->caller; 1510 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %04u %px ", 1511 area, sec, usec, level, except_str, 1512 entry->cpu, (void *)caller); 1513 return rc; 1514 } 1515 EXPORT_SYMBOL(debug_dflt_header_fn); 1516 1517 /* 1518 * prints debug data sprintf-formated: 1519 * debug_sprinf_event/exception calls must be used together with this view 1520 */ 1521 1522 #define DEBUG_SPRINTF_MAX_ARGS 10 1523 1524 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 1525 char *out_buf, const char *inbuf) 1526 { 1527 debug_sprintf_entry_t *curr_event = (debug_sprintf_entry_t *)inbuf; 1528 int num_longs, num_used_args = 0, i, rc = 0; 1529 int index[DEBUG_SPRINTF_MAX_ARGS]; 1530 1531 /* count of longs fit into one entry */ 1532 num_longs = id->buf_size / sizeof(long); 1533 1534 if (num_longs < 1) 1535 goto out; /* bufsize of entry too small */ 1536 if (num_longs == 1) { 1537 /* no args, we use only the string */ 1538 strcpy(out_buf, curr_event->string); 1539 rc = strlen(curr_event->string); 1540 goto out; 1541 } 1542 1543 /* number of arguments used for sprintf (without the format string) */ 1544 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1545 1546 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1547 1548 for (i = 0; i < num_used_args; i++) 1549 index[i] = i; 1550 1551 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1552 curr_event->args[index[1]], curr_event->args[index[2]], 1553 curr_event->args[index[3]], curr_event->args[index[4]], 1554 curr_event->args[index[5]], curr_event->args[index[6]], 1555 curr_event->args[index[7]], curr_event->args[index[8]], 1556 curr_event->args[index[9]]); 1557 out: 1558 return rc; 1559 } 1560 1561 /* 1562 * debug_init: 1563 * - is called exactly once to initialize the debug feature 1564 */ 1565 static int __init debug_init(void) 1566 { 1567 s390dbf_sysctl_header = register_sysctl("s390dbf", s390dbf_table); 1568 mutex_lock(&debug_mutex); 1569 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1570 initialized = 1; 1571 mutex_unlock(&debug_mutex); 1572 return 0; 1573 } 1574 postcore_initcall(debug_init); 1575