1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * S/390 debug facility 4 * 5 * Copyright IBM Corp. 1999, 2012 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/debugfs.h> 28 29 #include <asm/debug.h> 30 31 #define DEBUG_PROLOG_ENTRY -1 32 33 #define ALL_AREAS 0 /* copy all debug areas */ 34 #define NO_AREAS 1 /* copy no debug areas */ 35 36 /* typedefs */ 37 38 typedef struct file_private_info { 39 loff_t offset; /* offset of last read in file */ 40 int act_area; /* number of last formated area */ 41 int act_page; /* act page in given area */ 42 int act_entry; /* last formated entry (offset */ 43 /* relative to beginning of last */ 44 /* formated page) */ 45 size_t act_entry_offset; /* up to this offset we copied */ 46 /* in last read the last formated */ 47 /* entry to userland */ 48 char temp_buf[2048]; /* buffer for output */ 49 debug_info_t *debug_info_org; /* original debug information */ 50 debug_info_t *debug_info_snap; /* snapshot of debug information */ 51 struct debug_view *view; /* used view of debug info */ 52 } file_private_info_t; 53 54 typedef struct { 55 char *string; 56 /* 57 * This assumes that all args are converted into longs 58 * on L/390 this is the case for all types of parameter 59 * except of floats, and long long (32 bit) 60 * 61 */ 62 long args[0]; 63 } debug_sprintf_entry_t; 64 65 /* internal function prototyes */ 66 67 static int debug_init(void); 68 static ssize_t debug_output(struct file *file, char __user *user_buf, 69 size_t user_len, loff_t *offset); 70 static ssize_t debug_input(struct file *file, const char __user *user_buf, 71 size_t user_len, loff_t *offset); 72 static int debug_open(struct inode *inode, struct file *file); 73 static int debug_close(struct inode *inode, struct file *file); 74 static debug_info_t *debug_info_create(const char *name, int pages_per_area, 75 int nr_areas, int buf_size, umode_t mode); 76 static void debug_info_get(debug_info_t *); 77 static void debug_info_put(debug_info_t *); 78 static int debug_prolog_level_fn(debug_info_t *id, 79 struct debug_view *view, char *out_buf); 80 static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 81 struct file *file, const char __user *user_buf, 82 size_t user_buf_size, loff_t *offset); 83 static int debug_prolog_pages_fn(debug_info_t *id, 84 struct debug_view *view, char *out_buf); 85 static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, 86 struct file *file, const char __user *user_buf, 87 size_t user_buf_size, loff_t *offset); 88 static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 89 struct file *file, const char __user *user_buf, 90 size_t user_buf_size, loff_t *offset); 91 static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 92 char *out_buf, const char *in_buf); 93 static int debug_raw_format_fn(debug_info_t *id, 94 struct debug_view *view, char *out_buf, 95 const char *in_buf); 96 static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view, 97 int area, debug_entry_t *entry, char *out_buf); 98 99 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 100 char *out_buf, debug_sprintf_entry_t *curr_event); 101 102 /* globals */ 103 104 struct debug_view debug_raw_view = { 105 "raw", 106 NULL, 107 &debug_raw_header_fn, 108 &debug_raw_format_fn, 109 NULL, 110 NULL 111 }; 112 EXPORT_SYMBOL(debug_raw_view); 113 114 struct debug_view debug_hex_ascii_view = { 115 "hex_ascii", 116 NULL, 117 &debug_dflt_header_fn, 118 &debug_hex_ascii_format_fn, 119 NULL, 120 NULL 121 }; 122 EXPORT_SYMBOL(debug_hex_ascii_view); 123 124 static struct debug_view debug_level_view = { 125 "level", 126 &debug_prolog_level_fn, 127 NULL, 128 NULL, 129 &debug_input_level_fn, 130 NULL 131 }; 132 133 static struct debug_view debug_pages_view = { 134 "pages", 135 &debug_prolog_pages_fn, 136 NULL, 137 NULL, 138 &debug_input_pages_fn, 139 NULL 140 }; 141 142 static struct debug_view debug_flush_view = { 143 "flush", 144 NULL, 145 NULL, 146 NULL, 147 &debug_input_flush_fn, 148 NULL 149 }; 150 151 struct debug_view debug_sprintf_view = { 152 "sprintf", 153 NULL, 154 &debug_dflt_header_fn, 155 (debug_format_proc_t *)&debug_sprintf_format_fn, 156 NULL, 157 NULL 158 }; 159 EXPORT_SYMBOL(debug_sprintf_view); 160 161 /* used by dump analysis tools to determine version of debug feature */ 162 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 163 164 /* static globals */ 165 166 static debug_info_t *debug_area_first; 167 static debug_info_t *debug_area_last; 168 static DEFINE_MUTEX(debug_mutex); 169 170 static int initialized; 171 static int debug_critical; 172 173 static const struct file_operations debug_file_ops = { 174 .owner = THIS_MODULE, 175 .read = debug_output, 176 .write = debug_input, 177 .open = debug_open, 178 .release = debug_close, 179 .llseek = no_llseek, 180 }; 181 182 static struct dentry *debug_debugfs_root_entry; 183 184 /* functions */ 185 186 /* 187 * debug_areas_alloc 188 * - Debug areas are implemented as a threedimensonal array: 189 * areas[areanumber][pagenumber][pageoffset] 190 */ 191 192 static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas) 193 { 194 debug_entry_t ***areas; 195 int i, j; 196 197 areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL); 198 if (!areas) 199 goto fail_malloc_areas; 200 for (i = 0; i < nr_areas; i++) { 201 areas[i] = kmalloc_array(pages_per_area, 202 sizeof(debug_entry_t *), 203 GFP_KERNEL); 204 if (!areas[i]) 205 goto fail_malloc_areas2; 206 for (j = 0; j < pages_per_area; j++) { 207 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL); 208 if (!areas[i][j]) { 209 for (j--; j >= 0 ; j--) 210 kfree(areas[i][j]); 211 kfree(areas[i]); 212 goto fail_malloc_areas2; 213 } 214 } 215 } 216 return areas; 217 218 fail_malloc_areas2: 219 for (i--; i >= 0; i--) { 220 for (j = 0; j < pages_per_area; j++) 221 kfree(areas[i][j]); 222 kfree(areas[i]); 223 } 224 kfree(areas); 225 fail_malloc_areas: 226 return NULL; 227 } 228 229 /* 230 * debug_info_alloc 231 * - alloc new debug-info 232 */ 233 static debug_info_t *debug_info_alloc(const char *name, int pages_per_area, 234 int nr_areas, int buf_size, int level, 235 int mode) 236 { 237 debug_info_t *rc; 238 239 /* alloc everything */ 240 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL); 241 if (!rc) 242 goto fail_malloc_rc; 243 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 244 if (!rc->active_entries) 245 goto fail_malloc_active_entries; 246 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL); 247 if (!rc->active_pages) 248 goto fail_malloc_active_pages; 249 if ((mode == ALL_AREAS) && (pages_per_area != 0)) { 250 rc->areas = debug_areas_alloc(pages_per_area, nr_areas); 251 if (!rc->areas) 252 goto fail_malloc_areas; 253 } else { 254 rc->areas = NULL; 255 } 256 257 /* initialize members */ 258 spin_lock_init(&rc->lock); 259 rc->pages_per_area = pages_per_area; 260 rc->nr_areas = nr_areas; 261 rc->active_area = 0; 262 rc->level = level; 263 rc->buf_size = buf_size; 264 rc->entry_size = sizeof(debug_entry_t) + buf_size; 265 strlcpy(rc->name, name, sizeof(rc->name)); 266 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *)); 267 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *)); 268 refcount_set(&(rc->ref_count), 0); 269 270 return rc; 271 272 fail_malloc_areas: 273 kfree(rc->active_pages); 274 fail_malloc_active_pages: 275 kfree(rc->active_entries); 276 fail_malloc_active_entries: 277 kfree(rc); 278 fail_malloc_rc: 279 return NULL; 280 } 281 282 /* 283 * debug_areas_free 284 * - free all debug areas 285 */ 286 static void debug_areas_free(debug_info_t *db_info) 287 { 288 int i, j; 289 290 if (!db_info->areas) 291 return; 292 for (i = 0; i < db_info->nr_areas; i++) { 293 for (j = 0; j < db_info->pages_per_area; j++) 294 kfree(db_info->areas[i][j]); 295 kfree(db_info->areas[i]); 296 } 297 kfree(db_info->areas); 298 db_info->areas = NULL; 299 } 300 301 /* 302 * debug_info_free 303 * - free memory debug-info 304 */ 305 static void debug_info_free(debug_info_t *db_info) 306 { 307 debug_areas_free(db_info); 308 kfree(db_info->active_entries); 309 kfree(db_info->active_pages); 310 kfree(db_info); 311 } 312 313 /* 314 * debug_info_create 315 * - create new debug-info 316 */ 317 318 static debug_info_t *debug_info_create(const char *name, int pages_per_area, 319 int nr_areas, int buf_size, umode_t mode) 320 { 321 debug_info_t *rc; 322 323 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size, 324 DEBUG_DEFAULT_LEVEL, ALL_AREAS); 325 if (!rc) 326 goto out; 327 328 rc->mode = mode & ~S_IFMT; 329 330 /* create root directory */ 331 rc->debugfs_root_entry = debugfs_create_dir(rc->name, 332 debug_debugfs_root_entry); 333 334 /* append new element to linked list */ 335 if (!debug_area_first) { 336 /* first element in list */ 337 debug_area_first = rc; 338 rc->prev = NULL; 339 } else { 340 /* append element to end of list */ 341 debug_area_last->next = rc; 342 rc->prev = debug_area_last; 343 } 344 debug_area_last = rc; 345 rc->next = NULL; 346 347 refcount_set(&rc->ref_count, 1); 348 out: 349 return rc; 350 } 351 352 /* 353 * debug_info_copy 354 * - copy debug-info 355 */ 356 static debug_info_t *debug_info_copy(debug_info_t *in, int mode) 357 { 358 unsigned long flags; 359 debug_info_t *rc; 360 int i, j; 361 362 /* get a consistent copy of the debug areas */ 363 do { 364 rc = debug_info_alloc(in->name, in->pages_per_area, 365 in->nr_areas, in->buf_size, in->level, mode); 366 spin_lock_irqsave(&in->lock, flags); 367 if (!rc) 368 goto out; 369 /* has something changed in the meantime ? */ 370 if ((rc->pages_per_area == in->pages_per_area) && 371 (rc->nr_areas == in->nr_areas)) { 372 break; 373 } 374 spin_unlock_irqrestore(&in->lock, flags); 375 debug_info_free(rc); 376 } while (1); 377 378 if (mode == NO_AREAS) 379 goto out; 380 381 for (i = 0; i < in->nr_areas; i++) { 382 for (j = 0; j < in->pages_per_area; j++) 383 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE); 384 } 385 out: 386 spin_unlock_irqrestore(&in->lock, flags); 387 return rc; 388 } 389 390 /* 391 * debug_info_get 392 * - increments reference count for debug-info 393 */ 394 static void debug_info_get(debug_info_t *db_info) 395 { 396 if (db_info) 397 refcount_inc(&db_info->ref_count); 398 } 399 400 /* 401 * debug_info_put: 402 * - decreases reference count for debug-info and frees it if necessary 403 */ 404 static void debug_info_put(debug_info_t *db_info) 405 { 406 int i; 407 408 if (!db_info) 409 return; 410 if (refcount_dec_and_test(&db_info->ref_count)) { 411 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 412 if (!db_info->views[i]) 413 continue; 414 debugfs_remove(db_info->debugfs_entries[i]); 415 } 416 debugfs_remove(db_info->debugfs_root_entry); 417 if (db_info == debug_area_first) 418 debug_area_first = db_info->next; 419 if (db_info == debug_area_last) 420 debug_area_last = db_info->prev; 421 if (db_info->prev) 422 db_info->prev->next = db_info->next; 423 if (db_info->next) 424 db_info->next->prev = db_info->prev; 425 debug_info_free(db_info); 426 } 427 } 428 429 /* 430 * debug_format_entry: 431 * - format one debug entry and return size of formated data 432 */ 433 static int debug_format_entry(file_private_info_t *p_info) 434 { 435 debug_info_t *id_snap = p_info->debug_info_snap; 436 struct debug_view *view = p_info->view; 437 debug_entry_t *act_entry; 438 size_t len = 0; 439 440 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { 441 /* print prolog */ 442 if (view->prolog_proc) 443 len += view->prolog_proc(id_snap, view, p_info->temp_buf); 444 goto out; 445 } 446 if (!id_snap->areas) /* this is true, if we have a prolog only view */ 447 goto out; /* or if 'pages_per_area' is 0 */ 448 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area] 449 [p_info->act_page] + p_info->act_entry); 450 451 if (act_entry->id.stck == 0LL) 452 goto out; /* empty entry */ 453 if (view->header_proc) 454 len += view->header_proc(id_snap, view, p_info->act_area, 455 act_entry, p_info->temp_buf + len); 456 if (view->format_proc) 457 len += view->format_proc(id_snap, view, p_info->temp_buf + len, 458 DEBUG_DATA(act_entry)); 459 out: 460 return len; 461 } 462 463 /* 464 * debug_next_entry: 465 * - goto next entry in p_info 466 */ 467 static inline int debug_next_entry(file_private_info_t *p_info) 468 { 469 debug_info_t *id; 470 471 id = p_info->debug_info_snap; 472 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { 473 p_info->act_entry = 0; 474 p_info->act_page = 0; 475 goto out; 476 } 477 if (!id->areas) 478 return 1; 479 p_info->act_entry += id->entry_size; 480 /* switch to next page, if we reached the end of the page */ 481 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) { 482 /* next page */ 483 p_info->act_entry = 0; 484 p_info->act_page += 1; 485 if ((p_info->act_page % id->pages_per_area) == 0) { 486 /* next area */ 487 p_info->act_area++; 488 p_info->act_page = 0; 489 } 490 if (p_info->act_area >= id->nr_areas) 491 return 1; 492 } 493 out: 494 return 0; 495 } 496 497 /* 498 * debug_output: 499 * - called for user read() 500 * - copies formated debug entries to the user buffer 501 */ 502 static ssize_t debug_output(struct file *file, /* file descriptor */ 503 char __user *user_buf, /* user buffer */ 504 size_t len, /* length of buffer */ 505 loff_t *offset) /* offset in the file */ 506 { 507 size_t count = 0; 508 size_t entry_offset; 509 file_private_info_t *p_info; 510 511 p_info = (file_private_info_t *) file->private_data; 512 if (*offset != p_info->offset) 513 return -EPIPE; 514 if (p_info->act_area >= p_info->debug_info_snap->nr_areas) 515 return 0; 516 entry_offset = p_info->act_entry_offset; 517 while (count < len) { 518 int formatted_line_residue; 519 int formatted_line_size; 520 int user_buf_residue; 521 size_t copy_size; 522 523 formatted_line_size = debug_format_entry(p_info); 524 formatted_line_residue = formatted_line_size - entry_offset; 525 user_buf_residue = len-count; 526 copy_size = min(user_buf_residue, formatted_line_residue); 527 if (copy_size) { 528 if (copy_to_user(user_buf + count, p_info->temp_buf 529 + entry_offset, copy_size)) 530 return -EFAULT; 531 count += copy_size; 532 entry_offset += copy_size; 533 } 534 if (copy_size == formatted_line_residue) { 535 entry_offset = 0; 536 if (debug_next_entry(p_info)) 537 goto out; 538 } 539 } 540 out: 541 p_info->offset = *offset + count; 542 p_info->act_entry_offset = entry_offset; 543 *offset = p_info->offset; 544 return count; 545 } 546 547 /* 548 * debug_input: 549 * - called for user write() 550 * - calls input function of view 551 */ 552 static ssize_t debug_input(struct file *file, const char __user *user_buf, 553 size_t length, loff_t *offset) 554 { 555 file_private_info_t *p_info; 556 int rc = 0; 557 558 mutex_lock(&debug_mutex); 559 p_info = ((file_private_info_t *) file->private_data); 560 if (p_info->view->input_proc) { 561 rc = p_info->view->input_proc(p_info->debug_info_org, 562 p_info->view, file, user_buf, 563 length, offset); 564 } else { 565 rc = -EPERM; 566 } 567 mutex_unlock(&debug_mutex); 568 return rc; /* number of input characters */ 569 } 570 571 /* 572 * debug_open: 573 * - called for user open() 574 * - copies formated output to private_data area of the file 575 * handle 576 */ 577 static int debug_open(struct inode *inode, struct file *file) 578 { 579 debug_info_t *debug_info, *debug_info_snapshot; 580 file_private_info_t *p_info; 581 int i, rc = 0; 582 583 mutex_lock(&debug_mutex); 584 debug_info = file_inode(file)->i_private; 585 /* find debug view */ 586 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 587 if (!debug_info->views[i]) 588 continue; 589 else if (debug_info->debugfs_entries[i] == file->f_path.dentry) 590 goto found; /* found view ! */ 591 } 592 /* no entry found */ 593 rc = -EINVAL; 594 goto out; 595 596 found: 597 598 /* Make snapshot of current debug areas to get it consistent. */ 599 /* To copy all the areas is only needed, if we have a view which */ 600 /* formats the debug areas. */ 601 602 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc) 603 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS); 604 else 605 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS); 606 607 if (!debug_info_snapshot) { 608 rc = -ENOMEM; 609 goto out; 610 } 611 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL); 612 if (!p_info) { 613 debug_info_free(debug_info_snapshot); 614 rc = -ENOMEM; 615 goto out; 616 } 617 p_info->offset = 0; 618 p_info->debug_info_snap = debug_info_snapshot; 619 p_info->debug_info_org = debug_info; 620 p_info->view = debug_info->views[i]; 621 p_info->act_area = 0; 622 p_info->act_page = 0; 623 p_info->act_entry = DEBUG_PROLOG_ENTRY; 624 p_info->act_entry_offset = 0; 625 file->private_data = p_info; 626 debug_info_get(debug_info); 627 nonseekable_open(inode, file); 628 out: 629 mutex_unlock(&debug_mutex); 630 return rc; 631 } 632 633 /* 634 * debug_close: 635 * - called for user close() 636 * - deletes private_data area of the file handle 637 */ 638 static int debug_close(struct inode *inode, struct file *file) 639 { 640 file_private_info_t *p_info; 641 642 p_info = (file_private_info_t *) file->private_data; 643 if (p_info->debug_info_snap) 644 debug_info_free(p_info->debug_info_snap); 645 debug_info_put(p_info->debug_info_org); 646 kfree(file->private_data); 647 return 0; /* success */ 648 } 649 650 /* 651 * debug_register_mode: 652 * - Creates and initializes debug area for the caller 653 * The mode parameter allows to specify access rights for the s390dbf files 654 * - Returns handle for debug area 655 */ 656 debug_info_t *debug_register_mode(const char *name, int pages_per_area, 657 int nr_areas, int buf_size, umode_t mode, 658 uid_t uid, gid_t gid) 659 { 660 debug_info_t *rc = NULL; 661 662 /* Since debugfs currently does not support uid/gid other than root, */ 663 /* we do not allow gid/uid != 0 until we get support for that. */ 664 if ((uid != 0) || (gid != 0)) 665 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n"); 666 BUG_ON(!initialized); 667 mutex_lock(&debug_mutex); 668 669 /* create new debug_info */ 670 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 671 if (!rc) 672 goto out; 673 debug_register_view(rc, &debug_level_view); 674 debug_register_view(rc, &debug_flush_view); 675 debug_register_view(rc, &debug_pages_view); 676 out: 677 if (!rc) 678 pr_err("Registering debug feature %s failed\n", name); 679 mutex_unlock(&debug_mutex); 680 return rc; 681 } 682 EXPORT_SYMBOL(debug_register_mode); 683 684 /* 685 * debug_register: 686 * - creates and initializes debug area for the caller 687 * - returns handle for debug area 688 */ 689 debug_info_t *debug_register(const char *name, int pages_per_area, 690 int nr_areas, int buf_size) 691 { 692 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 693 S_IRUSR | S_IWUSR, 0, 0); 694 } 695 EXPORT_SYMBOL(debug_register); 696 697 /* 698 * debug_unregister: 699 * - give back debug area 700 */ 701 void debug_unregister(debug_info_t *id) 702 { 703 if (!id) 704 return; 705 mutex_lock(&debug_mutex); 706 debug_info_put(id); 707 mutex_unlock(&debug_mutex); 708 } 709 EXPORT_SYMBOL(debug_unregister); 710 711 /* 712 * debug_set_size: 713 * - set area size (number of pages) and number of areas 714 */ 715 static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area) 716 { 717 debug_entry_t ***new_areas; 718 unsigned long flags; 719 int rc = 0; 720 721 if (!id || (nr_areas <= 0) || (pages_per_area < 0)) 722 return -EINVAL; 723 if (pages_per_area > 0) { 724 new_areas = debug_areas_alloc(pages_per_area, nr_areas); 725 if (!new_areas) { 726 pr_info("Allocating memory for %i pages failed\n", 727 pages_per_area); 728 rc = -ENOMEM; 729 goto out; 730 } 731 } else { 732 new_areas = NULL; 733 } 734 spin_lock_irqsave(&id->lock, flags); 735 debug_areas_free(id); 736 id->areas = new_areas; 737 id->nr_areas = nr_areas; 738 id->pages_per_area = pages_per_area; 739 id->active_area = 0; 740 memset(id->active_entries, 0, sizeof(int)*id->nr_areas); 741 memset(id->active_pages, 0, sizeof(int)*id->nr_areas); 742 spin_unlock_irqrestore(&id->lock, flags); 743 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area); 744 out: 745 return rc; 746 } 747 748 /* 749 * debug_set_level: 750 * - set actual debug level 751 */ 752 void debug_set_level(debug_info_t *id, int new_level) 753 { 754 unsigned long flags; 755 756 if (!id) 757 return; 758 spin_lock_irqsave(&id->lock, flags); 759 if (new_level == DEBUG_OFF_LEVEL) { 760 id->level = DEBUG_OFF_LEVEL; 761 pr_info("%s: switched off\n", id->name); 762 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 763 pr_info("%s: level %i is out of range (%i - %i)\n", 764 id->name, new_level, 0, DEBUG_MAX_LEVEL); 765 } else { 766 id->level = new_level; 767 } 768 spin_unlock_irqrestore(&id->lock, flags); 769 } 770 EXPORT_SYMBOL(debug_set_level); 771 772 /* 773 * proceed_active_entry: 774 * - set active entry to next in the ring buffer 775 */ 776 static inline void proceed_active_entry(debug_info_t *id) 777 { 778 if ((id->active_entries[id->active_area] += id->entry_size) 779 > (PAGE_SIZE - id->entry_size)) { 780 id->active_entries[id->active_area] = 0; 781 id->active_pages[id->active_area] = 782 (id->active_pages[id->active_area] + 1) % 783 id->pages_per_area; 784 } 785 } 786 787 /* 788 * proceed_active_area: 789 * - set active area to next in the ring buffer 790 */ 791 static inline void proceed_active_area(debug_info_t *id) 792 { 793 id->active_area++; 794 id->active_area = id->active_area % id->nr_areas; 795 } 796 797 /* 798 * get_active_entry: 799 */ 800 static inline debug_entry_t *get_active_entry(debug_info_t *id) 801 { 802 return (debug_entry_t *) (((char *) id->areas[id->active_area] 803 [id->active_pages[id->active_area]]) + 804 id->active_entries[id->active_area]); 805 } 806 807 /* 808 * debug_finish_entry: 809 * - set timestamp, caller address, cpu number etc. 810 */ 811 812 static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active, 813 int level, int exception) 814 { 815 active->id.stck = get_tod_clock_fast() - 816 *(unsigned long long *) &tod_clock_base[1]; 817 active->id.fields.cpuid = smp_processor_id(); 818 active->caller = __builtin_return_address(0); 819 active->id.fields.exception = exception; 820 active->id.fields.level = level; 821 proceed_active_entry(id); 822 if (exception) 823 proceed_active_area(id); 824 } 825 826 static int debug_stoppable = 1; 827 static int debug_active = 1; 828 829 #define CTL_S390DBF_STOPPABLE 5678 830 #define CTL_S390DBF_ACTIVE 5679 831 832 /* 833 * proc handler for the running debug_active sysctl 834 * always allow read, allow write only if debug_stoppable is set or 835 * if debug_active is already off 836 */ 837 static int s390dbf_procactive(struct ctl_table *table, int write, 838 void __user *buffer, size_t *lenp, loff_t *ppos) 839 { 840 if (!write || debug_stoppable || !debug_active) 841 return proc_dointvec(table, write, buffer, lenp, ppos); 842 else 843 return 0; 844 } 845 846 static struct ctl_table s390dbf_table[] = { 847 { 848 .procname = "debug_stoppable", 849 .data = &debug_stoppable, 850 .maxlen = sizeof(int), 851 .mode = S_IRUGO | S_IWUSR, 852 .proc_handler = proc_dointvec, 853 }, 854 { 855 .procname = "debug_active", 856 .data = &debug_active, 857 .maxlen = sizeof(int), 858 .mode = S_IRUGO | S_IWUSR, 859 .proc_handler = s390dbf_procactive, 860 }, 861 { } 862 }; 863 864 static struct ctl_table s390dbf_dir_table[] = { 865 { 866 .procname = "s390dbf", 867 .maxlen = 0, 868 .mode = S_IRUGO | S_IXUGO, 869 .child = s390dbf_table, 870 }, 871 { } 872 }; 873 874 static struct ctl_table_header *s390dbf_sysctl_header; 875 876 void debug_stop_all(void) 877 { 878 if (debug_stoppable) 879 debug_active = 0; 880 } 881 EXPORT_SYMBOL(debug_stop_all); 882 883 void debug_set_critical(void) 884 { 885 debug_critical = 1; 886 } 887 888 /* 889 * debug_event_common: 890 * - write debug entry with given size 891 */ 892 debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf, 893 int len) 894 { 895 debug_entry_t *active; 896 unsigned long flags; 897 898 if (!debug_active || !id->areas) 899 return NULL; 900 if (debug_critical) { 901 if (!spin_trylock_irqsave(&id->lock, flags)) 902 return NULL; 903 } else { 904 spin_lock_irqsave(&id->lock, flags); 905 } 906 do { 907 active = get_active_entry(id); 908 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 909 if (len < id->buf_size) 910 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 911 debug_finish_entry(id, active, level, 0); 912 len -= id->buf_size; 913 buf += id->buf_size; 914 } while (len > 0); 915 916 spin_unlock_irqrestore(&id->lock, flags); 917 return active; 918 } 919 EXPORT_SYMBOL(debug_event_common); 920 921 /* 922 * debug_exception_common: 923 * - write debug entry with given size and switch to next debug area 924 */ 925 debug_entry_t *debug_exception_common(debug_info_t *id, int level, 926 const void *buf, int len) 927 { 928 debug_entry_t *active; 929 unsigned long flags; 930 931 if (!debug_active || !id->areas) 932 return NULL; 933 if (debug_critical) { 934 if (!spin_trylock_irqsave(&id->lock, flags)) 935 return NULL; 936 } else { 937 spin_lock_irqsave(&id->lock, flags); 938 } 939 do { 940 active = get_active_entry(id); 941 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 942 if (len < id->buf_size) 943 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 944 debug_finish_entry(id, active, level, len <= id->buf_size); 945 len -= id->buf_size; 946 buf += id->buf_size; 947 } while (len > 0); 948 949 spin_unlock_irqrestore(&id->lock, flags); 950 return active; 951 } 952 EXPORT_SYMBOL(debug_exception_common); 953 954 /* 955 * counts arguments in format string for sprintf view 956 */ 957 static inline int debug_count_numargs(char *string) 958 { 959 int numargs = 0; 960 961 while (*string) { 962 if (*string++ == '%') 963 numargs++; 964 } 965 return numargs; 966 } 967 968 /* 969 * debug_sprintf_event: 970 */ 971 debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 972 { 973 debug_sprintf_entry_t *curr_event; 974 debug_entry_t *active; 975 unsigned long flags; 976 int numargs, idx; 977 va_list ap; 978 979 if (!debug_active || !id->areas) 980 return NULL; 981 numargs = debug_count_numargs(string); 982 983 if (debug_critical) { 984 if (!spin_trylock_irqsave(&id->lock, flags)) 985 return NULL; 986 } else { 987 spin_lock_irqsave(&id->lock, flags); 988 } 989 active = get_active_entry(id); 990 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active); 991 va_start(ap, string); 992 curr_event->string = string; 993 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 994 curr_event->args[idx] = va_arg(ap, long); 995 va_end(ap); 996 debug_finish_entry(id, active, level, 0); 997 spin_unlock_irqrestore(&id->lock, flags); 998 999 return active; 1000 } 1001 EXPORT_SYMBOL(__debug_sprintf_event); 1002 1003 /* 1004 * debug_sprintf_exception: 1005 */ 1006 debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 1007 { 1008 debug_sprintf_entry_t *curr_event; 1009 debug_entry_t *active; 1010 unsigned long flags; 1011 int numargs, idx; 1012 va_list ap; 1013 1014 if (!debug_active || !id->areas) 1015 return NULL; 1016 1017 numargs = debug_count_numargs(string); 1018 1019 if (debug_critical) { 1020 if (!spin_trylock_irqsave(&id->lock, flags)) 1021 return NULL; 1022 } else { 1023 spin_lock_irqsave(&id->lock, flags); 1024 } 1025 active = get_active_entry(id); 1026 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active); 1027 va_start(ap, string); 1028 curr_event->string = string; 1029 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1030 curr_event->args[idx] = va_arg(ap, long); 1031 va_end(ap); 1032 debug_finish_entry(id, active, level, 1); 1033 spin_unlock_irqrestore(&id->lock, flags); 1034 1035 return active; 1036 } 1037 EXPORT_SYMBOL(__debug_sprintf_exception); 1038 1039 /* 1040 * debug_register_view: 1041 */ 1042 int debug_register_view(debug_info_t *id, struct debug_view *view) 1043 { 1044 unsigned long flags; 1045 struct dentry *pde; 1046 umode_t mode; 1047 int rc = 0; 1048 int i; 1049 1050 if (!id) 1051 goto out; 1052 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1053 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1054 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1055 if (!view->input_proc) 1056 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1057 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1058 id, &debug_file_ops); 1059 spin_lock_irqsave(&id->lock, flags); 1060 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1061 if (!id->views[i]) 1062 break; 1063 } 1064 if (i == DEBUG_MAX_VIEWS) { 1065 pr_err("Registering view %s/%s would exceed the maximum " 1066 "number of views %i\n", id->name, view->name, i); 1067 rc = -1; 1068 } else { 1069 id->views[i] = view; 1070 id->debugfs_entries[i] = pde; 1071 } 1072 spin_unlock_irqrestore(&id->lock, flags); 1073 if (rc) 1074 debugfs_remove(pde); 1075 out: 1076 return rc; 1077 } 1078 EXPORT_SYMBOL(debug_register_view); 1079 1080 /* 1081 * debug_unregister_view: 1082 */ 1083 int debug_unregister_view(debug_info_t *id, struct debug_view *view) 1084 { 1085 struct dentry *dentry = NULL; 1086 unsigned long flags; 1087 int i, rc = 0; 1088 1089 if (!id) 1090 goto out; 1091 spin_lock_irqsave(&id->lock, flags); 1092 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1093 if (id->views[i] == view) 1094 break; 1095 } 1096 if (i == DEBUG_MAX_VIEWS) { 1097 rc = -1; 1098 } else { 1099 dentry = id->debugfs_entries[i]; 1100 id->views[i] = NULL; 1101 id->debugfs_entries[i] = NULL; 1102 } 1103 spin_unlock_irqrestore(&id->lock, flags); 1104 debugfs_remove(dentry); 1105 out: 1106 return rc; 1107 } 1108 EXPORT_SYMBOL(debug_unregister_view); 1109 1110 static inline char *debug_get_user_string(const char __user *user_buf, 1111 size_t user_len) 1112 { 1113 char *buffer; 1114 1115 buffer = kmalloc(user_len + 1, GFP_KERNEL); 1116 if (!buffer) 1117 return ERR_PTR(-ENOMEM); 1118 if (copy_from_user(buffer, user_buf, user_len) != 0) { 1119 kfree(buffer); 1120 return ERR_PTR(-EFAULT); 1121 } 1122 /* got the string, now strip linefeed. */ 1123 if (buffer[user_len - 1] == '\n') 1124 buffer[user_len - 1] = 0; 1125 else 1126 buffer[user_len] = 0; 1127 return buffer; 1128 } 1129 1130 static inline int debug_get_uint(char *buf) 1131 { 1132 int rc; 1133 1134 buf = skip_spaces(buf); 1135 rc = simple_strtoul(buf, &buf, 10); 1136 if (*buf) 1137 rc = -EINVAL; 1138 return rc; 1139 } 1140 1141 /* 1142 * functions for debug-views 1143 *********************************** 1144 */ 1145 1146 /* 1147 * prints out actual debug level 1148 */ 1149 1150 static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view, 1151 char *out_buf) 1152 { 1153 return sprintf(out_buf, "%i\n", id->pages_per_area); 1154 } 1155 1156 /* 1157 * reads new size (number of pages per debug area) 1158 */ 1159 1160 static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, 1161 struct file *file, const char __user *user_buf, 1162 size_t user_len, loff_t *offset) 1163 { 1164 int rc, new_pages; 1165 char *str; 1166 1167 if (user_len > 0x10000) 1168 user_len = 0x10000; 1169 if (*offset != 0) { 1170 rc = -EPIPE; 1171 goto out; 1172 } 1173 str = debug_get_user_string(user_buf, user_len); 1174 if (IS_ERR(str)) { 1175 rc = PTR_ERR(str); 1176 goto out; 1177 } 1178 new_pages = debug_get_uint(str); 1179 if (new_pages < 0) { 1180 rc = -EINVAL; 1181 goto free_str; 1182 } 1183 rc = debug_set_size(id, id->nr_areas, new_pages); 1184 if (rc != 0) { 1185 rc = -EINVAL; 1186 goto free_str; 1187 } 1188 rc = user_len; 1189 free_str: 1190 kfree(str); 1191 out: 1192 *offset += user_len; 1193 return rc; /* number of input characters */ 1194 } 1195 1196 /* 1197 * prints out actual debug level 1198 */ 1199 static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view, 1200 char *out_buf) 1201 { 1202 int rc = 0; 1203 1204 if (id->level == DEBUG_OFF_LEVEL) 1205 rc = sprintf(out_buf, "-\n"); 1206 else 1207 rc = sprintf(out_buf, "%i\n", id->level); 1208 return rc; 1209 } 1210 1211 /* 1212 * reads new debug level 1213 */ 1214 static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 1215 struct file *file, const char __user *user_buf, 1216 size_t user_len, loff_t *offset) 1217 { 1218 int rc, new_level; 1219 char *str; 1220 1221 if (user_len > 0x10000) 1222 user_len = 0x10000; 1223 if (*offset != 0) { 1224 rc = -EPIPE; 1225 goto out; 1226 } 1227 str = debug_get_user_string(user_buf, user_len); 1228 if (IS_ERR(str)) { 1229 rc = PTR_ERR(str); 1230 goto out; 1231 } 1232 if (str[0] == '-') { 1233 debug_set_level(id, DEBUG_OFF_LEVEL); 1234 rc = user_len; 1235 goto free_str; 1236 } else { 1237 new_level = debug_get_uint(str); 1238 } 1239 if (new_level < 0) { 1240 pr_warn("%s is not a valid level for a debug feature\n", str); 1241 rc = -EINVAL; 1242 } else { 1243 debug_set_level(id, new_level); 1244 rc = user_len; 1245 } 1246 free_str: 1247 kfree(str); 1248 out: 1249 *offset += user_len; 1250 return rc; /* number of input characters */ 1251 } 1252 1253 /* 1254 * flushes debug areas 1255 */ 1256 static void debug_flush(debug_info_t *id, int area) 1257 { 1258 unsigned long flags; 1259 int i, j; 1260 1261 if (!id || !id->areas) 1262 return; 1263 spin_lock_irqsave(&id->lock, flags); 1264 if (area == DEBUG_FLUSH_ALL) { 1265 id->active_area = 0; 1266 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1267 for (i = 0; i < id->nr_areas; i++) { 1268 id->active_pages[i] = 0; 1269 for (j = 0; j < id->pages_per_area; j++) 1270 memset(id->areas[i][j], 0, PAGE_SIZE); 1271 } 1272 } else if (area >= 0 && area < id->nr_areas) { 1273 id->active_entries[area] = 0; 1274 id->active_pages[area] = 0; 1275 for (i = 0; i < id->pages_per_area; i++) 1276 memset(id->areas[area][i], 0, PAGE_SIZE); 1277 } 1278 spin_unlock_irqrestore(&id->lock, flags); 1279 } 1280 1281 /* 1282 * view function: flushes debug areas 1283 */ 1284 static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 1285 struct file *file, const char __user *user_buf, 1286 size_t user_len, loff_t *offset) 1287 { 1288 char input_buf[1]; 1289 int rc = user_len; 1290 1291 if (user_len > 0x10000) 1292 user_len = 0x10000; 1293 if (*offset != 0) { 1294 rc = -EPIPE; 1295 goto out; 1296 } 1297 if (copy_from_user(input_buf, user_buf, 1)) { 1298 rc = -EFAULT; 1299 goto out; 1300 } 1301 if (input_buf[0] == '-') { 1302 debug_flush(id, DEBUG_FLUSH_ALL); 1303 goto out; 1304 } 1305 if (isdigit(input_buf[0])) { 1306 int area = ((int) input_buf[0] - (int) '0'); 1307 1308 debug_flush(id, area); 1309 goto out; 1310 } 1311 1312 pr_info("Flushing debug data failed because %c is not a valid " 1313 "area\n", input_buf[0]); 1314 1315 out: 1316 *offset += user_len; 1317 return rc; /* number of input characters */ 1318 } 1319 1320 /* 1321 * prints debug header in raw format 1322 */ 1323 static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view, 1324 int area, debug_entry_t *entry, char *out_buf) 1325 { 1326 int rc; 1327 1328 rc = sizeof(debug_entry_t); 1329 memcpy(out_buf, entry, sizeof(debug_entry_t)); 1330 return rc; 1331 } 1332 1333 /* 1334 * prints debug data in raw format 1335 */ 1336 static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view, 1337 char *out_buf, const char *in_buf) 1338 { 1339 int rc; 1340 1341 rc = id->buf_size; 1342 memcpy(out_buf, in_buf, id->buf_size); 1343 return rc; 1344 } 1345 1346 /* 1347 * prints debug data in hex/ascii format 1348 */ 1349 static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 1350 char *out_buf, const char *in_buf) 1351 { 1352 int i, rc = 0; 1353 1354 for (i = 0; i < id->buf_size; i++) 1355 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]); 1356 rc += sprintf(out_buf + rc, "| "); 1357 for (i = 0; i < id->buf_size; i++) { 1358 unsigned char c = in_buf[i]; 1359 1360 if (isascii(c) && isprint(c)) 1361 rc += sprintf(out_buf + rc, "%c", c); 1362 else 1363 rc += sprintf(out_buf + rc, "."); 1364 } 1365 rc += sprintf(out_buf + rc, "\n"); 1366 return rc; 1367 } 1368 1369 /* 1370 * prints header for debug entry 1371 */ 1372 int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view, 1373 int area, debug_entry_t *entry, char *out_buf) 1374 { 1375 unsigned long base, sec, usec; 1376 unsigned long caller; 1377 unsigned int level; 1378 char *except_str; 1379 int rc = 0; 1380 1381 level = entry->id.fields.level; 1382 base = (*(unsigned long *) &tod_clock_base[0]) >> 4; 1383 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12); 1384 usec = do_div(sec, USEC_PER_SEC); 1385 1386 if (entry->id.fields.exception) 1387 except_str = "*"; 1388 else 1389 except_str = "-"; 1390 caller = (unsigned long) entry->caller; 1391 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ", 1392 area, sec, usec, level, except_str, 1393 entry->id.fields.cpuid, (void *)caller); 1394 return rc; 1395 } 1396 EXPORT_SYMBOL(debug_dflt_header_fn); 1397 1398 /* 1399 * prints debug data sprintf-formated: 1400 * debug_sprinf_event/exception calls must be used together with this view 1401 */ 1402 1403 #define DEBUG_SPRINTF_MAX_ARGS 10 1404 1405 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 1406 char *out_buf, debug_sprintf_entry_t *curr_event) 1407 { 1408 int num_longs, num_used_args = 0, i, rc = 0; 1409 int index[DEBUG_SPRINTF_MAX_ARGS]; 1410 1411 /* count of longs fit into one entry */ 1412 num_longs = id->buf_size / sizeof(long); 1413 1414 if (num_longs < 1) 1415 goto out; /* bufsize of entry too small */ 1416 if (num_longs == 1) { 1417 /* no args, we use only the string */ 1418 strcpy(out_buf, curr_event->string); 1419 rc = strlen(curr_event->string); 1420 goto out; 1421 } 1422 1423 /* number of arguments used for sprintf (without the format string) */ 1424 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1425 1426 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1427 1428 for (i = 0; i < num_used_args; i++) 1429 index[i] = i; 1430 1431 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]], 1432 curr_event->args[index[1]], curr_event->args[index[2]], 1433 curr_event->args[index[3]], curr_event->args[index[4]], 1434 curr_event->args[index[5]], curr_event->args[index[6]], 1435 curr_event->args[index[7]], curr_event->args[index[8]], 1436 curr_event->args[index[9]]); 1437 out: 1438 return rc; 1439 } 1440 1441 /* 1442 * debug_init: 1443 * - is called exactly once to initialize the debug feature 1444 */ 1445 static int __init debug_init(void) 1446 { 1447 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table); 1448 mutex_lock(&debug_mutex); 1449 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1450 initialized = 1; 1451 mutex_unlock(&debug_mutex); 1452 return 0; 1453 } 1454 postcore_initcall(debug_init); 1455