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 39typedef 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 55typedef 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 68static int debug_init(void); 69static ssize_t debug_output(struct file *file, char __user *user_buf, 70 size_t user_len, loff_t *offset); 71static ssize_t debug_input(struct file *file, const char __user *user_buf, 72 size_t user_len, loff_t *offset); 73static int debug_open(struct inode *inode, struct file *file); 74static int debug_close(struct inode *inode, struct file *file); 75static debug_info_t *debug_info_create(const char *name, int pages_per_area, 76 int nr_areas, int buf_size, umode_t mode); 77static void debug_info_get(debug_info_t *); 78static void debug_info_put(debug_info_t *); 79static int debug_prolog_level_fn(debug_info_t *id, 80 struct debug_view *view, char *out_buf); 81static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 82 struct file *file, const char __user *user_buf, 83 size_t user_buf_size, loff_t *offset); 84static int debug_prolog_pages_fn(debug_info_t *id, 85 struct debug_view *view, char *out_buf); 86static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, 87 struct file *file, const char __user *user_buf, 88 size_t user_buf_size, loff_t *offset); 89static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 90 struct file *file, const char __user *user_buf, 91 size_t user_buf_size, loff_t *offset); 92static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 93 char *out_buf, const char *in_buf); 94static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 95 char *out_buf, const char *inbuf); 96static void debug_areas_swap(debug_info_t *a, debug_info_t *b); 97static void debug_events_append(debug_info_t *dest, debug_info_t *src); 98 99/* globals */ 100 101struct 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}; 109EXPORT_SYMBOL(debug_hex_ascii_view); 110 111static 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 120static 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 129static struct debug_view debug_flush_view = { 130 "flush", 131 NULL, 132 NULL, 133 NULL, 134 &debug_input_flush_fn, 135 NULL 136}; 137 138struct debug_view debug_sprintf_view = { 139 "sprintf", 140 NULL, 141 &debug_dflt_header_fn, 142 &debug_sprintf_format_fn, 143 NULL, 144 NULL 145}; 146EXPORT_SYMBOL(debug_sprintf_view); 147 148/* used by dump analysis tools to determine version of debug feature */ 149static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 150 151/* static globals */ 152 153static debug_info_t *debug_area_first; 154static debug_info_t *debug_area_last; 155static DEFINE_MUTEX(debug_mutex); 156 157static int initialized; 158static int debug_critical; 159 160static 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 169static 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 179static 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 206fail_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); 213fail_malloc_areas: 214 return NULL; 215} 216 217/* 218 * debug_info_alloc 219 * - alloc new debug-info 220 */ 221static 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 260fail_malloc_areas: 261 kfree(rc->active_pages); 262fail_malloc_active_pages: 263 kfree(rc->active_entries); 264fail_malloc_active_entries: 265 kfree(rc); 266fail_malloc_rc: 267 return NULL; 268} 269 270/* 271 * debug_areas_free 272 * - free all debug areas 273 */ 274static 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 */ 293static 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 306static 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); 318out: 319 return rc; 320} 321 322/* 323 * debug_info_copy 324 * - copy debug-info 325 */ 326static 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 } 355out: 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 */ 364static 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 */ 374static 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 */ 386static 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)); 412out: 413 return len; 414} 415 416/* 417 * debug_next_entry: 418 * - goto next entry in p_info 419 */ 420static 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 } 446out: 447 return 0; 448} 449 450/* 451 * debug_output: 452 * - called for user read() 453 * - copies formated debug entries to the user buffer 454 */ 455static 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 } 493out: 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 */ 505static 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 */ 530static 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 549found: 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); 581out: 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 */ 591static 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. */ 604static 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 */ 646debug_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} 669EXPORT_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 */ 687debug_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} 693EXPORT_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 */ 707void 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. */ 751static 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 */ 779void 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} 789EXPORT_SYMBOL(debug_unregister); 790 791/* 792 * debug_set_size: 793 * - set area size (number of pages) and number of areas 794 */ 795static 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 */ 830void 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} 849EXPORT_SYMBOL(debug_set_level); 850 851/* 852 * proceed_active_entry: 853 * - set active entry to next in the ring buffer 854 */ 855static 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 */ 870static 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 */ 879static 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. */ 887static 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. */ 898static 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 927static 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 946static int debug_stoppable = 1; 947static 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 */ 957static 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 966static 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 983static struct ctl_table_header *s390dbf_sysctl_header; 984 985/** 986 * debug_stop_all() - stops the debug feature if stopping is allowed. 987 * 988 * Return: 989 * - none 990 * 991 * Currently used in case of a kernel oops. 992 */ 993void debug_stop_all(void) 994{ 995 if (debug_stoppable) 996 debug_active = 0; 997} 998EXPORT_SYMBOL(debug_stop_all); 999 1000/** 1001 * debug_set_critical() - event/exception functions try lock instead of spin. 1002 * 1003 * Return: 1004 * - none 1005 * 1006 * Currently used in case of stopping all CPUs but the current one. 1007 * Once in this state, functions to write a debug entry for an 1008 * event or exception no longer spin on the debug area lock, 1009 * but only try to get it and fail if they do not get the lock. 1010 */ 1011void debug_set_critical(void) 1012{ 1013 debug_critical = 1; 1014} 1015 1016/* 1017 * debug_event_common: 1018 * - write debug entry with given size 1019 */ 1020debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf, 1021 int len) 1022{ 1023 debug_entry_t *active; 1024 unsigned long flags; 1025 1026 if (!debug_active || !id->areas) 1027 return NULL; 1028 if (debug_critical) { 1029 if (!spin_trylock_irqsave(&id->lock, flags)) 1030 return NULL; 1031 } else { 1032 spin_lock_irqsave(&id->lock, flags); 1033 } 1034 do { 1035 active = get_active_entry(id); 1036 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1037 if (len < id->buf_size) 1038 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1039 debug_finish_entry(id, active, level, 0); 1040 len -= id->buf_size; 1041 buf += id->buf_size; 1042 } while (len > 0); 1043 1044 spin_unlock_irqrestore(&id->lock, flags); 1045 return active; 1046} 1047EXPORT_SYMBOL(debug_event_common); 1048 1049/* 1050 * debug_exception_common: 1051 * - write debug entry with given size and switch to next debug area 1052 */ 1053debug_entry_t *debug_exception_common(debug_info_t *id, int level, 1054 const void *buf, int len) 1055{ 1056 debug_entry_t *active; 1057 unsigned long flags; 1058 1059 if (!debug_active || !id->areas) 1060 return NULL; 1061 if (debug_critical) { 1062 if (!spin_trylock_irqsave(&id->lock, flags)) 1063 return NULL; 1064 } else { 1065 spin_lock_irqsave(&id->lock, flags); 1066 } 1067 do { 1068 active = get_active_entry(id); 1069 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1070 if (len < id->buf_size) 1071 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1072 debug_finish_entry(id, active, level, len <= id->buf_size); 1073 len -= id->buf_size; 1074 buf += id->buf_size; 1075 } while (len > 0); 1076 1077 spin_unlock_irqrestore(&id->lock, flags); 1078 return active; 1079} 1080EXPORT_SYMBOL(debug_exception_common); 1081 1082/* 1083 * counts arguments in format string for sprintf view 1084 */ 1085static inline int debug_count_numargs(char *string) 1086{ 1087 int numargs = 0; 1088 1089 while (*string) { 1090 if (*string++ == '%') 1091 numargs++; 1092 } 1093 return numargs; 1094} 1095 1096/* 1097 * debug_sprintf_event: 1098 */ 1099debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 1100{ 1101 debug_sprintf_entry_t *curr_event; 1102 debug_entry_t *active; 1103 unsigned long flags; 1104 int numargs, idx; 1105 va_list ap; 1106 1107 if (!debug_active || !id->areas) 1108 return NULL; 1109 numargs = debug_count_numargs(string); 1110 1111 if (debug_critical) { 1112 if (!spin_trylock_irqsave(&id->lock, flags)) 1113 return NULL; 1114 } else { 1115 spin_lock_irqsave(&id->lock, flags); 1116 } 1117 active = get_active_entry(id); 1118 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active); 1119 va_start(ap, string); 1120 curr_event->string = string; 1121 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1122 curr_event->args[idx] = va_arg(ap, long); 1123 va_end(ap); 1124 debug_finish_entry(id, active, level, 0); 1125 spin_unlock_irqrestore(&id->lock, flags); 1126 1127 return active; 1128} 1129EXPORT_SYMBOL(__debug_sprintf_event); 1130 1131/* 1132 * debug_sprintf_exception: 1133 */ 1134debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 1135{ 1136 debug_sprintf_entry_t *curr_event; 1137 debug_entry_t *active; 1138 unsigned long flags; 1139 int numargs, idx; 1140 va_list ap; 1141 1142 if (!debug_active || !id->areas) 1143 return NULL; 1144 1145 numargs = debug_count_numargs(string); 1146 1147 if (debug_critical) { 1148 if (!spin_trylock_irqsave(&id->lock, flags)) 1149 return NULL; 1150 } else { 1151 spin_lock_irqsave(&id->lock, flags); 1152 } 1153 active = get_active_entry(id); 1154 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active); 1155 va_start(ap, string); 1156 curr_event->string = string; 1157 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1158 curr_event->args[idx] = va_arg(ap, long); 1159 va_end(ap); 1160 debug_finish_entry(id, active, level, 1); 1161 spin_unlock_irqrestore(&id->lock, flags); 1162 1163 return active; 1164} 1165EXPORT_SYMBOL(__debug_sprintf_exception); 1166 1167/** 1168 * debug_register_view() - registers new debug view and creates debugfs 1169 * dir entry 1170 * 1171 * @id: handle for debug log 1172 * @view: pointer to debug view struct 1173 * 1174 * Return: 1175 * - 0 : ok 1176 * - < 0: Error 1177 */ 1178int debug_register_view(debug_info_t *id, struct debug_view *view) 1179{ 1180 unsigned long flags; 1181 struct dentry *pde; 1182 umode_t mode; 1183 int rc = 0; 1184 int i; 1185 1186 if (!id) 1187 goto out; 1188 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1189 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1190 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1191 if (!view->input_proc) 1192 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1193 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1194 id, &debug_file_ops); 1195 spin_lock_irqsave(&id->lock, flags); 1196 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1197 if (!id->views[i]) 1198 break; 1199 } 1200 if (i == DEBUG_MAX_VIEWS) { 1201 rc = -1; 1202 } else { 1203 id->views[i] = view; 1204 id->debugfs_entries[i] = pde; 1205 } 1206 spin_unlock_irqrestore(&id->lock, flags); 1207 if (rc) { 1208 pr_err("Registering view %s/%s would exceed the maximum " 1209 "number of views %i\n", id->name, view->name, i); 1210 debugfs_remove(pde); 1211 } 1212out: 1213 return rc; 1214} 1215EXPORT_SYMBOL(debug_register_view); 1216 1217/** 1218 * debug_unregister_view() - unregisters debug view and removes debugfs 1219 * dir entry 1220 * 1221 * @id: handle for debug log 1222 * @view: pointer to debug view struct 1223 * 1224 * Return: 1225 * - 0 : ok 1226 * - < 0: Error 1227 */ 1228int debug_unregister_view(debug_info_t *id, struct debug_view *view) 1229{ 1230 struct dentry *dentry = NULL; 1231 unsigned long flags; 1232 int i, rc = 0; 1233 1234 if (!id) 1235 goto out; 1236 spin_lock_irqsave(&id->lock, flags); 1237 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1238 if (id->views[i] == view) 1239 break; 1240 } 1241 if (i == DEBUG_MAX_VIEWS) { 1242 rc = -1; 1243 } else { 1244 dentry = id->debugfs_entries[i]; 1245 id->views[i] = NULL; 1246 id->debugfs_entries[i] = NULL; 1247 } 1248 spin_unlock_irqrestore(&id->lock, flags); 1249 debugfs_remove(dentry); 1250out: 1251 return rc; 1252} 1253EXPORT_SYMBOL(debug_unregister_view); 1254 1255static inline char *debug_get_user_string(const char __user *user_buf, 1256 size_t user_len) 1257{ 1258 char *buffer; 1259 1260 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1261 if (!buffer) 1262 return ERR_PTR(-ENOMEM); 1263 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1264 kfree(buffer); 1265 return ERR_PTR(-EFAULT); 1266 } 1267 /* got the string, now strip linefeed. */ 1268 if (buffer[user_len - 1] == '\n') 1269 buffer[user_len - 1] = 0; 1270 else 1271 buffer[user_len] = 0; 1272 return buffer; 1273} 1274 1275static inline int debug_get_uint(char *buf) 1276{ 1277 int rc; 1278 1279 buf = skip_spaces(buf); 1280 rc = simple_strtoul(buf, &buf, 10); 1281 if (*buf) 1282 rc = -EINVAL; 1283 return rc; 1284} 1285 1286/* 1287 * functions for debug-views 1288 *********************************** 1289*/ 1290 1291/* 1292 * prints out actual debug level 1293 */ 1294 1295static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view, 1296 char *out_buf) 1297{ 1298 return sprintf(out_buf, "%i\n", id->pages_per_area); 1299} 1300 1301/* 1302 * reads new size (number of pages per debug area) 1303 */ 1304 1305static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, 1306 struct file *file, const char __user *user_buf, 1307 size_t user_len, loff_t *offset) 1308{ 1309 int rc, new_pages; 1310 char *str; 1311 1312 if (user_len > 0x10000) 1313 user_len = 0x10000; 1314 if (*offset != 0) { 1315 rc = -EPIPE; 1316 goto out; 1317 } 1318 str = debug_get_user_string(user_buf, user_len); 1319 if (IS_ERR(str)) { 1320 rc = PTR_ERR(str); 1321 goto out; 1322 } 1323 new_pages = debug_get_uint(str); 1324 if (new_pages < 0) { 1325 rc = -EINVAL; 1326 goto free_str; 1327 } 1328 rc = debug_set_size(id, id->nr_areas, new_pages); 1329 if (rc != 0) { 1330 rc = -EINVAL; 1331 goto free_str; 1332 } 1333 rc = user_len; 1334free_str: 1335 kfree(str); 1336out: 1337 *offset += user_len; 1338 return rc; /* number of input characters */ 1339} 1340 1341/* 1342 * prints out actual debug level 1343 */ 1344static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view, 1345 char *out_buf) 1346{ 1347 int rc = 0; 1348 1349 if (id->level == DEBUG_OFF_LEVEL) 1350 rc = sprintf(out_buf, "-\n"); 1351 else 1352 rc = sprintf(out_buf, "%i\n", id->level); 1353 return rc; 1354} 1355 1356/* 1357 * reads new debug level 1358 */ 1359static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 1360 struct file *file, const char __user *user_buf, 1361 size_t user_len, loff_t *offset) 1362{ 1363 int rc, new_level; 1364 char *str; 1365 1366 if (user_len > 0x10000) 1367 user_len = 0x10000; 1368 if (*offset != 0) { 1369 rc = -EPIPE; 1370 goto out; 1371 } 1372 str = debug_get_user_string(user_buf, user_len); 1373 if (IS_ERR(str)) { 1374 rc = PTR_ERR(str); 1375 goto out; 1376 } 1377 if (str[0] == '-') { 1378 debug_set_level(id, DEBUG_OFF_LEVEL); 1379 rc = user_len; 1380 goto free_str; 1381 } else { 1382 new_level = debug_get_uint(str); 1383 } 1384 if (new_level < 0) { 1385 pr_warn("%s is not a valid level for a debug feature\n", str); 1386 rc = -EINVAL; 1387 } else { 1388 debug_set_level(id, new_level); 1389 rc = user_len; 1390 } 1391free_str: 1392 kfree(str); 1393out: 1394 *offset += user_len; 1395 return rc; /* number of input characters */ 1396} 1397 1398/* 1399 * flushes debug areas 1400 */ 1401static void debug_flush(debug_info_t *id, int area) 1402{ 1403 unsigned long flags; 1404 int i, j; 1405 1406 if (!id || !id->areas) 1407 return; 1408 spin_lock_irqsave(&id->lock, flags); 1409 if (area == DEBUG_FLUSH_ALL) { 1410 id->active_area = 0; 1411 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1412 for (i = 0; i < id->nr_areas; i++) { 1413 id->active_pages[i] = 0; 1414 for (j = 0; j < id->pages_per_area; j++) 1415 memset(id->areas[i][j], 0, PAGE_SIZE); 1416 } 1417 } else if (area >= 0 && area < id->nr_areas) { 1418 id->active_entries[area] = 0; 1419 id->active_pages[area] = 0; 1420 for (i = 0; i < id->pages_per_area; i++) 1421 memset(id->areas[area][i], 0, PAGE_SIZE); 1422 } 1423 spin_unlock_irqrestore(&id->lock, flags); 1424} 1425 1426/* 1427 * view function: flushes debug areas 1428 */ 1429static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 1430 struct file *file, const char __user *user_buf, 1431 size_t user_len, loff_t *offset) 1432{ 1433 char input_buf[1]; 1434 int rc = user_len; 1435 1436 if (user_len > 0x10000) 1437 user_len = 0x10000; 1438 if (*offset != 0) { 1439 rc = -EPIPE; 1440 goto out; 1441 } 1442 if (copy_from_user(input_buf, user_buf, 1)) { 1443 rc = -EFAULT; 1444 goto out; 1445 } 1446 if (input_buf[0] == '-') { 1447 debug_flush(id, DEBUG_FLUSH_ALL); 1448 goto out; 1449 } 1450 if (isdigit(input_buf[0])) { 1451 int area = ((int) input_buf[0] - (int) '0'); 1452 1453 debug_flush(id, area); 1454 goto out; 1455 } 1456 1457 pr_info("Flushing debug data failed because %c is not a valid " 1458 "area\n", input_buf[0]); 1459 1460out: 1461 *offset += user_len; 1462 return rc; /* number of input characters */ 1463} 1464 1465/* 1466 * prints debug data in hex/ascii format 1467 */ 1468static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 1469 char *out_buf, const char *in_buf) 1470{ 1471 int i, rc = 0; 1472 1473 for (i = 0; i < id->buf_size; i++) 1474 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]); 1475 rc += sprintf(out_buf + rc, "| "); 1476 for (i = 0; i < id->buf_size; i++) { 1477 unsigned char c = in_buf[i]; 1478 1479 if (isascii(c) && isprint(c)) 1480 rc += sprintf(out_buf + rc, "%c", c); 1481 else 1482 rc += sprintf(out_buf + rc, "."); 1483 } 1484 rc += sprintf(out_buf + rc, "\n"); 1485 return rc; 1486} 1487 1488/* 1489 * prints header for debug entry 1490 */ 1491int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view, 1492 int area, debug_entry_t *entry, char *out_buf) 1493{ 1494 unsigned long sec, usec; 1495 unsigned long caller; 1496 unsigned int level; 1497 char *except_str; 1498 int rc = 0; 1499 1500 level = entry->level; 1501 sec = entry->clock; 1502 usec = do_div(sec, USEC_PER_SEC); 1503 1504 if (entry->exception) 1505 except_str = "*"; 1506 else 1507 except_str = "-"; 1508 caller = (unsigned long) entry->caller; 1509 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %04u %px ", 1510 area, sec, usec, level, except_str, 1511 entry->cpu, (void *)caller); 1512 return rc; 1513} 1514EXPORT_SYMBOL(debug_dflt_header_fn); 1515 1516/* 1517 * prints debug data sprintf-formated: 1518 * debug_sprinf_event/exception calls must be used together with this view 1519 */ 1520 1521#define DEBUG_SPRINTF_MAX_ARGS 10 1522 1523static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 1524 char *out_buf, const char *inbuf) 1525{ 1526 debug_sprintf_entry_t *curr_event = (debug_sprintf_entry_t *)inbuf; 1527 int num_longs, num_used_args = 0, i, rc = 0; 1528 int index[DEBUG_SPRINTF_MAX_ARGS]; 1529 1530 /* count of longs fit into one entry */ 1531 num_longs = id->buf_size / sizeof(long); 1532 1533 if (num_longs < 1) 1534 goto out; /* bufsize of entry too small */ 1535 if (num_longs == 1) { 1536 /* no args, we use only the string */ 1537 strcpy(out_buf, curr_event->string); 1538 rc = strlen(curr_event->string); 1539 goto out; 1540 } 1541 1542 /* number of arguments used for sprintf (without the format string) */ 1543 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1544 1545 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1546 1547 for (i = 0; i < num_used_args; i++) 1548 index[i] = i; 1549 1550 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1551 curr_event->args[index[1]], curr_event->args[index[2]], 1552 curr_event->args[index[3]], curr_event->args[index[4]], 1553 curr_event->args[index[5]], curr_event->args[index[6]], 1554 curr_event->args[index[7]], curr_event->args[index[8]], 1555 curr_event->args[index[9]]); 1556out: 1557 return rc; 1558} 1559 1560/* 1561 * debug_init: 1562 * - is called exactly once to initialize the debug feature 1563 */ 1564static int __init debug_init(void) 1565{ 1566 s390dbf_sysctl_header = register_sysctl("s390dbf", s390dbf_table); 1567 mutex_lock(&debug_mutex); 1568 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1569 initialized = 1; 1570 mutex_unlock(&debug_mutex); 1571 return 0; 1572} 1573postcore_initcall(debug_init); 1574