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debug.c
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linux-6.19.14/arch/s390/kernel/debug.c
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 pr_fmt(fmt) "s390dbf: " fmt 14 15#include <linux/stddef.h> 16#include <linux/kernel.h> 17#include <linux/errno.h> 18#include <linux/slab.h> 19#include <linux/ctype.h> 20#include <linux/string.h> 21#include <linux/sysctl.h> 22#include <linux/uaccess.h> 23#include <linux/export.h> 24#include <linux/init.h> 25#include <linux/fs.h> 26#include <linux/math.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 formatted area */ 42 int act_page; /* act page in given area */ 43 int act_entry; /* last formatted entry (offset */ 44 /* relative to beginning of last */ 45 /* formatted page) */ 46 size_t act_entry_offset; /* up to this offset we copied */ 47 /* in last read the last formatted */ 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 prototypes */ 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, 81 size_t out_buf_size); 82static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 83 struct file *file, const char __user *user_buf, 84 size_t user_buf_size, loff_t *offset); 85static int debug_prolog_pages_fn(debug_info_t *id, 86 struct debug_view *view, char *out_buf, 87 size_t out_buf_size); 88static int debug_input_pages_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); 91static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 92 struct file *file, const char __user *user_buf, 93 size_t user_buf_size, loff_t *offset); 94static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 95 char *out_buf, size_t out_buf_size, 96 const char *in_buf); 97static void debug_areas_swap(debug_info_t *a, debug_info_t *b); 98static void debug_events_append(debug_info_t *dest, debug_info_t *src); 99 100/* globals */ 101 102struct debug_view debug_hex_ascii_view = { 103 "hex_ascii", 104 NULL, 105 &debug_dflt_header_fn, 106 &debug_hex_ascii_format_fn, 107 NULL, 108 NULL 109}; 110EXPORT_SYMBOL(debug_hex_ascii_view); 111 112static struct debug_view debug_level_view = { 113 "level", 114 &debug_prolog_level_fn, 115 NULL, 116 NULL, 117 &debug_input_level_fn, 118 NULL 119}; 120 121static struct debug_view debug_pages_view = { 122 "pages", 123 &debug_prolog_pages_fn, 124 NULL, 125 NULL, 126 &debug_input_pages_fn, 127 NULL 128}; 129 130static struct debug_view debug_flush_view = { 131 "flush", 132 NULL, 133 NULL, 134 NULL, 135 &debug_input_flush_fn, 136 NULL 137}; 138 139struct debug_view debug_sprintf_view = { 140 "sprintf", 141 NULL, 142 &debug_dflt_header_fn, 143 &debug_sprintf_format_fn, 144 NULL, 145 NULL 146}; 147EXPORT_SYMBOL(debug_sprintf_view); 148 149/* used by dump analysis tools to determine version of debug feature */ 150static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION; 151 152/* static globals */ 153 154static debug_info_t *debug_area_first; 155static debug_info_t *debug_area_last; 156static DEFINE_MUTEX(debug_mutex); 157 158static int initialized; 159static int debug_critical; 160 161static const struct file_operations debug_file_ops = { 162 .owner = THIS_MODULE, 163 .read = debug_output, 164 .write = debug_input, 165 .open = debug_open, 166 .release = debug_close, 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); 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 rc->active_pages[i] = in->active_pages[i]; 355 rc->active_entries[i] = in->active_entries[i]; 356 } 357 rc->active_area = in->active_area; 358out: 359 spin_unlock_irqrestore(&in->lock, flags); 360 return rc; 361} 362 363/* 364 * debug_info_get 365 * - increments reference count for debug-info 366 */ 367static void debug_info_get(debug_info_t *db_info) 368{ 369 if (db_info) 370 refcount_inc(&db_info->ref_count); 371} 372 373/* 374 * debug_info_put: 375 * - decreases reference count for debug-info and frees it if necessary 376 */ 377static void debug_info_put(debug_info_t *db_info) 378{ 379 if (!db_info) 380 return; 381 if (refcount_dec_and_test(&db_info->ref_count)) 382 debug_info_free(db_info); 383} 384 385/* 386 * debug_format_entry: 387 * - format one debug entry and return size of formatted data 388 */ 389static int debug_format_entry(file_private_info_t *p_info) 390{ 391 debug_info_t *id_snap = p_info->debug_info_snap; 392 struct debug_view *view = p_info->view; 393 debug_entry_t *act_entry; 394 size_t len = 0; 395 396 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { 397 /* print prolog */ 398 if (view->prolog_proc) { 399 len += view->prolog_proc(id_snap, view, p_info->temp_buf, 400 sizeof(p_info->temp_buf)); 401 } 402 goto out; 403 } 404 if (!id_snap->areas) /* this is true, if we have a prolog only view */ 405 goto out; /* or if 'pages_per_area' is 0 */ 406 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area] 407 [p_info->act_page] + p_info->act_entry); 408 409 if (act_entry->clock == 0LL) 410 goto out; /* empty entry */ 411 if (view->header_proc) { 412 len += view->header_proc(id_snap, view, p_info->act_area, 413 act_entry, p_info->temp_buf + len, 414 sizeof(p_info->temp_buf) - len); 415 } 416 if (view->format_proc) { 417 len += view->format_proc(id_snap, view, p_info->temp_buf + len, 418 sizeof(p_info->temp_buf) - len, 419 DEBUG_DATA(act_entry)); 420 } 421out: 422 return len; 423} 424 425/** 426 * debug_next_entry - Go to the next entry 427 * @p_info: Private info that is manipulated 428 * 429 * Sets the current position in @p_info to the next entry. If no further entry 430 * exists the current position is set to one after the end the return value 431 * indicates that no further entries exist. 432 * 433 * Return: True if there are more following entries, false otherwise 434 */ 435static inline bool debug_next_entry(file_private_info_t *p_info) 436{ 437 debug_info_t *id; 438 439 id = p_info->debug_info_snap; 440 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) { 441 p_info->act_entry = 0; 442 p_info->act_page = 0; 443 return true; 444 } 445 if (!id->areas) 446 return false; 447 p_info->act_entry += id->entry_size; 448 /* switch to next page, if we reached the end of the page */ 449 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) { 450 /* next page */ 451 p_info->act_entry = 0; 452 p_info->act_page += 1; 453 if ((p_info->act_page % id->pages_per_area) == 0) { 454 /* next area */ 455 p_info->act_area++; 456 p_info->act_page = 0; 457 } 458 if (p_info->act_area >= id->nr_areas) 459 return false; 460 } 461 return true; 462} 463 464/** 465 * debug_to_act_entry - Go to the currently active entry 466 * @p_info: Private info that is manipulated 467 * 468 * Sets the current position in @p_info to the currently active 469 * entry of @p_info->debug_info_snap 470 */ 471static void debug_to_act_entry(file_private_info_t *p_info) 472{ 473 debug_info_t *snap_id; 474 475 snap_id = p_info->debug_info_snap; 476 p_info->act_area = snap_id->active_area; 477 p_info->act_page = snap_id->active_pages[snap_id->active_area]; 478 p_info->act_entry = snap_id->active_entries[snap_id->active_area]; 479} 480 481/** 482 * debug_prev_entry - Go to the previous entry 483 * @p_info: Private info that is manipulated 484 * 485 * Sets the current position in @p_info to the previous entry. If no previous entry 486 * exists the current position is set left as DEBUG_PROLOG_ENTRY and the return value 487 * indicates that no previous entries exist. 488 * 489 * Return: True if there are more previous entries, false otherwise 490 */ 491 492static inline bool debug_prev_entry(file_private_info_t *p_info) 493{ 494 debug_info_t *id; 495 496 id = p_info->debug_info_snap; 497 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) 498 debug_to_act_entry(p_info); 499 if (!id->areas) 500 return false; 501 p_info->act_entry -= id->entry_size; 502 /* switch to prev page, if we reached the beginning of the page */ 503 if (p_info->act_entry < 0) { 504 /* end of previous page */ 505 p_info->act_entry = rounddown(PAGE_SIZE, id->entry_size) - id->entry_size; 506 p_info->act_page--; 507 if (p_info->act_page < 0) { 508 /* previous area */ 509 p_info->act_area--; 510 p_info->act_page = id->pages_per_area - 1; 511 } 512 if (p_info->act_area < 0) 513 p_info->act_area = (id->nr_areas - 1) % id->nr_areas; 514 } 515 /* check full circle */ 516 if (id->active_area == p_info->act_area && 517 id->active_pages[id->active_area] == p_info->act_page && 518 id->active_entries[id->active_area] == p_info->act_entry) 519 return false; 520 return true; 521} 522 523/** 524 * debug_move_entry - Go to next entry in either the forward or backward direction 525 * @p_info: Private info that is manipulated 526 * @reverse: If true go to the next entry in reverse i.e. previous 527 * 528 * Sets the current position in @p_info to the next (@reverse == false) or 529 * previous (@reverse == true) entry. 530 * 531 * Return: True if there are further entries in that direction, 532 * false otherwise. 533 */ 534static bool debug_move_entry(file_private_info_t *p_info, bool reverse) 535{ 536 if (reverse) 537 return debug_prev_entry(p_info); 538 else 539 return debug_next_entry(p_info); 540} 541 542/* 543 * debug_output: 544 * - called for user read() 545 * - copies formatted debug entries to the user buffer 546 */ 547static ssize_t debug_output(struct file *file, /* file descriptor */ 548 char __user *user_buf, /* user buffer */ 549 size_t len, /* length of buffer */ 550 loff_t *offset) /* offset in the file */ 551{ 552 size_t count = 0; 553 size_t entry_offset; 554 file_private_info_t *p_info; 555 556 p_info = (file_private_info_t *) file->private_data; 557 if (*offset != p_info->offset) 558 return -EPIPE; 559 if (p_info->act_area >= p_info->debug_info_snap->nr_areas) 560 return 0; 561 entry_offset = p_info->act_entry_offset; 562 while (count < len) { 563 int formatted_line_residue; 564 int formatted_line_size; 565 int user_buf_residue; 566 size_t copy_size; 567 568 formatted_line_size = debug_format_entry(p_info); 569 formatted_line_residue = formatted_line_size - entry_offset; 570 user_buf_residue = len-count; 571 copy_size = min(user_buf_residue, formatted_line_residue); 572 if (copy_size) { 573 if (copy_to_user(user_buf + count, p_info->temp_buf 574 + entry_offset, copy_size)) 575 return -EFAULT; 576 count += copy_size; 577 entry_offset += copy_size; 578 } 579 if (copy_size == formatted_line_residue) { 580 entry_offset = 0; 581 if (!debug_next_entry(p_info)) 582 goto out; 583 } 584 } 585out: 586 p_info->offset = *offset + count; 587 p_info->act_entry_offset = entry_offset; 588 *offset = p_info->offset; 589 return count; 590} 591 592/* 593 * debug_input: 594 * - called for user write() 595 * - calls input function of view 596 */ 597static ssize_t debug_input(struct file *file, const char __user *user_buf, 598 size_t length, loff_t *offset) 599{ 600 file_private_info_t *p_info; 601 int rc = 0; 602 603 mutex_lock(&debug_mutex); 604 p_info = ((file_private_info_t *) file->private_data); 605 if (p_info->view->input_proc) { 606 rc = p_info->view->input_proc(p_info->debug_info_org, 607 p_info->view, file, user_buf, 608 length, offset); 609 } else { 610 rc = -EPERM; 611 } 612 mutex_unlock(&debug_mutex); 613 return rc; /* number of input characters */ 614} 615 616static file_private_info_t *debug_file_private_alloc(debug_info_t *debug_info, 617 struct debug_view *view) 618{ 619 debug_info_t *debug_info_snapshot; 620 file_private_info_t *p_info; 621 622 /* 623 * Make snapshot of current debug areas to get it consistent. 624 * To copy all the areas is only needed, if we have a view which 625 * formats the debug areas. 626 */ 627 if (!view->format_proc && !view->header_proc) 628 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS); 629 else 630 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS); 631 632 if (!debug_info_snapshot) 633 return NULL; 634 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL); 635 if (!p_info) { 636 debug_info_free(debug_info_snapshot); 637 return NULL; 638 } 639 p_info->offset = 0; 640 p_info->debug_info_snap = debug_info_snapshot; 641 p_info->debug_info_org = debug_info; 642 p_info->view = view; 643 p_info->act_area = 0; 644 p_info->act_page = 0; 645 p_info->act_entry = DEBUG_PROLOG_ENTRY; 646 p_info->act_entry_offset = 0; 647 debug_info_get(debug_info); 648 649 return p_info; 650} 651 652/* 653 * debug_open: 654 * - called for user open() 655 * - copies formatted output to private_data area of the file 656 * handle 657 */ 658static int debug_open(struct inode *inode, struct file *file) 659{ 660 debug_info_t *debug_info; 661 file_private_info_t *p_info; 662 int i, rc = 0; 663 664 mutex_lock(&debug_mutex); 665 debug_info = file_inode(file)->i_private; 666 /* find debug view */ 667 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 668 if (!debug_info->views[i]) 669 continue; 670 else if (debug_info->debugfs_entries[i] == file->f_path.dentry) 671 goto found; /* found view ! */ 672 } 673 /* no entry found */ 674 rc = -EINVAL; 675 goto out; 676 677found: 678 p_info = debug_file_private_alloc(debug_info, debug_info->views[i]); 679 if (!p_info) { 680 rc = -ENOMEM; 681 goto out; 682 } 683 file->private_data = p_info; 684 nonseekable_open(inode, file); 685out: 686 mutex_unlock(&debug_mutex); 687 return rc; 688} 689 690static void debug_file_private_free(file_private_info_t *p_info) 691{ 692 if (p_info->debug_info_snap) 693 debug_info_free(p_info->debug_info_snap); 694 debug_info_put(p_info->debug_info_org); 695 kfree(p_info); 696} 697 698/* 699 * debug_close: 700 * - called for user close() 701 * - deletes private_data area of the file handle 702 */ 703static int debug_close(struct inode *inode, struct file *file) 704{ 705 file_private_info_t *p_info; 706 707 p_info = (file_private_info_t *) file->private_data; 708 debug_file_private_free(p_info); 709 file->private_data = NULL; 710 return 0; /* success */ 711} 712 713/** 714 * debug_dump - Get a textual representation of debug info, or as much as fits 715 * @id: Debug information to use 716 * @view: View with which to dump the debug information 717 * @buf: Buffer the textual debug data representation is written to 718 * @buf_size: Size of the buffer, including the trailing '\0' byte 719 * @reverse: Go backwards from the last written entry 720 * 721 * This function may be used whenever a textual representation of the debug 722 * information is required without using an s390dbf file. 723 * 724 * Note: It is the callers responsibility to supply a view that is compatible 725 * with the debug information data. 726 * 727 * Return: On success returns the number of bytes written to the buffer not 728 * including the trailing '\0' byte. If bug_size == 0 the function returns 0. 729 * On failure an error code less than 0 is returned. 730 */ 731ssize_t debug_dump(debug_info_t *id, struct debug_view *view, 732 char *buf, size_t buf_size, bool reverse) 733{ 734 file_private_info_t *p_info; 735 size_t size, offset = 0; 736 737 /* Need space for '\0' byte */ 738 if (buf_size < 1) 739 return 0; 740 buf_size--; 741 742 p_info = debug_file_private_alloc(id, view); 743 if (!p_info) 744 return -ENOMEM; 745 746 /* There is always at least the DEBUG_PROLOG_ENTRY */ 747 do { 748 size = debug_format_entry(p_info); 749 size = min(size, buf_size - offset); 750 memcpy(buf + offset, p_info->temp_buf, size); 751 offset += size; 752 if (offset >= buf_size) 753 break; 754 } while (debug_move_entry(p_info, reverse)); 755 debug_file_private_free(p_info); 756 buf[offset] = '\0'; 757 758 return offset; 759} 760 761/* Create debugfs entries and add to internal list. */ 762static void _debug_register(debug_info_t *id) 763{ 764 /* create root directory */ 765 id->debugfs_root_entry = debugfs_create_dir(id->name, 766 debug_debugfs_root_entry); 767 768 /* append new element to linked list */ 769 if (!debug_area_first) { 770 /* first element in list */ 771 debug_area_first = id; 772 id->prev = NULL; 773 } else { 774 /* append element to end of list */ 775 debug_area_last->next = id; 776 id->prev = debug_area_last; 777 } 778 debug_area_last = id; 779 id->next = NULL; 780 781 debug_register_view(id, &debug_level_view); 782 debug_register_view(id, &debug_flush_view); 783 debug_register_view(id, &debug_pages_view); 784} 785 786/** 787 * debug_register_mode() - creates and initializes debug area. 788 * 789 * @name: Name of debug log (e.g. used for debugfs entry) 790 * @pages_per_area: Number of pages, which will be allocated per area 791 * @nr_areas: Number of debug areas 792 * @buf_size: Size of data area in each debug entry 793 * @mode: File mode for debugfs files. E.g. S_IRWXUGO 794 * @uid: User ID for debugfs files. Currently only 0 is supported. 795 * @gid: Group ID for debugfs files. Currently only 0 is supported. 796 * 797 * Return: 798 * - Handle for generated debug area 799 * - %NULL if register failed 800 * 801 * Allocates memory for a debug log. 802 * Must not be called within an interrupt handler. 803 */ 804debug_info_t *debug_register_mode(const char *name, int pages_per_area, 805 int nr_areas, int buf_size, umode_t mode, 806 uid_t uid, gid_t gid) 807{ 808 debug_info_t *rc = NULL; 809 810 /* Since debugfs currently does not support uid/gid other than root, */ 811 /* we do not allow gid/uid != 0 until we get support for that. */ 812 if ((uid != 0) || (gid != 0)) 813 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n"); 814 BUG_ON(!initialized); 815 816 /* create new debug_info */ 817 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode); 818 if (rc) { 819 mutex_lock(&debug_mutex); 820 _debug_register(rc); 821 mutex_unlock(&debug_mutex); 822 } else { 823 pr_err("Registering debug feature %s failed\n", name); 824 } 825 return rc; 826} 827EXPORT_SYMBOL(debug_register_mode); 828 829/** 830 * debug_register() - creates and initializes debug area with default file mode. 831 * 832 * @name: Name of debug log (e.g. used for debugfs entry) 833 * @pages_per_area: Number of pages, which will be allocated per area 834 * @nr_areas: Number of debug areas 835 * @buf_size: Size of data area in each debug entry 836 * 837 * Return: 838 * - Handle for generated debug area 839 * - %NULL if register failed 840 * 841 * Allocates memory for a debug log. 842 * The debugfs file mode access permissions are read and write for user. 843 * Must not be called within an interrupt handler. 844 */ 845debug_info_t *debug_register(const char *name, int pages_per_area, 846 int nr_areas, int buf_size) 847{ 848 return debug_register_mode(name, pages_per_area, nr_areas, buf_size, 849 S_IRUSR | S_IWUSR, 0, 0); 850} 851EXPORT_SYMBOL(debug_register); 852 853/** 854 * debug_register_static() - registers a static debug area 855 * 856 * @id: Handle for static debug area 857 * @pages_per_area: Number of pages per area 858 * @nr_areas: Number of debug areas 859 * 860 * Register debug_info_t defined using DEFINE_STATIC_DEBUG_INFO. 861 * 862 * Note: This function is called automatically via an initcall generated by 863 * DEFINE_STATIC_DEBUG_INFO. 864 */ 865void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas) 866{ 867 unsigned long flags; 868 debug_info_t *copy; 869 870 if (!initialized) { 871 pr_err("Tried to register debug feature %s too early\n", 872 id->name); 873 return; 874 } 875 876 copy = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size, 877 id->level, ALL_AREAS); 878 if (!copy) { 879 pr_err("Registering debug feature %s failed\n", id->name); 880 881 /* Clear pointers to prevent tracing into released initdata. */ 882 spin_lock_irqsave(&id->lock, flags); 883 id->areas = NULL; 884 id->active_pages = NULL; 885 id->active_entries = NULL; 886 spin_unlock_irqrestore(&id->lock, flags); 887 888 return; 889 } 890 891 /* Replace static trace area with dynamic copy. */ 892 spin_lock_irqsave(&id->lock, flags); 893 debug_events_append(copy, id); 894 debug_areas_swap(id, copy); 895 spin_unlock_irqrestore(&id->lock, flags); 896 897 /* Clear pointers to initdata and discard copy. */ 898 copy->areas = NULL; 899 copy->active_pages = NULL; 900 copy->active_entries = NULL; 901 debug_info_free(copy); 902 903 mutex_lock(&debug_mutex); 904 _debug_register(id); 905 mutex_unlock(&debug_mutex); 906} 907 908/* Remove debugfs entries and remove from internal list. */ 909static void _debug_unregister(debug_info_t *id) 910{ 911 int i; 912 913 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 914 if (!id->views[i]) 915 continue; 916 debugfs_remove(id->debugfs_entries[i]); 917 } 918 debugfs_remove(id->debugfs_root_entry); 919 if (id == debug_area_first) 920 debug_area_first = id->next; 921 if (id == debug_area_last) 922 debug_area_last = id->prev; 923 if (id->prev) 924 id->prev->next = id->next; 925 if (id->next) 926 id->next->prev = id->prev; 927} 928 929/** 930 * debug_unregister() - give back debug area. 931 * 932 * @id: handle for debug log 933 * 934 * Return: 935 * none 936 */ 937void debug_unregister(debug_info_t *id) 938{ 939 if (!id) 940 return; 941 mutex_lock(&debug_mutex); 942 _debug_unregister(id); 943 mutex_unlock(&debug_mutex); 944 945 debug_info_put(id); 946} 947EXPORT_SYMBOL(debug_unregister); 948 949/* 950 * debug_set_size: 951 * - set area size (number of pages) and number of areas 952 */ 953static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area) 954{ 955 debug_info_t *new_id; 956 unsigned long flags; 957 958 if (!id || (nr_areas <= 0) || (pages_per_area < 0)) 959 return -EINVAL; 960 961 new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size, 962 id->level, ALL_AREAS); 963 if (!new_id) { 964 pr_info("Allocating memory for %i pages failed\n", 965 pages_per_area); 966 return -ENOMEM; 967 } 968 969 spin_lock_irqsave(&id->lock, flags); 970 debug_events_append(new_id, id); 971 debug_areas_swap(new_id, id); 972 debug_info_free(new_id); 973 spin_unlock_irqrestore(&id->lock, flags); 974 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area); 975 976 return 0; 977} 978 979/** 980 * debug_set_level() - Sets new actual debug level if new_level is valid. 981 * 982 * @id: handle for debug log 983 * @new_level: new debug level 984 * 985 * Return: 986 * none 987 */ 988void debug_set_level(debug_info_t *id, int new_level) 989{ 990 unsigned long flags; 991 992 if (!id) 993 return; 994 995 if (new_level == DEBUG_OFF_LEVEL) { 996 pr_info("%s: switched off\n", id->name); 997 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) { 998 pr_info("%s: level %i is out of range (%i - %i)\n", 999 id->name, new_level, 0, DEBUG_MAX_LEVEL); 1000 return; 1001 } 1002 1003 spin_lock_irqsave(&id->lock, flags); 1004 id->level = new_level; 1005 spin_unlock_irqrestore(&id->lock, flags); 1006} 1007EXPORT_SYMBOL(debug_set_level); 1008 1009/* 1010 * proceed_active_entry: 1011 * - set active entry to next in the ring buffer 1012 */ 1013static inline void proceed_active_entry(debug_info_t *id) 1014{ 1015 if ((id->active_entries[id->active_area] += id->entry_size) 1016 > (PAGE_SIZE - id->entry_size)) { 1017 id->active_entries[id->active_area] = 0; 1018 id->active_pages[id->active_area] = 1019 (id->active_pages[id->active_area] + 1) % 1020 id->pages_per_area; 1021 } 1022} 1023 1024/* 1025 * proceed_active_area: 1026 * - set active area to next in the ring buffer 1027 */ 1028static inline void proceed_active_area(debug_info_t *id) 1029{ 1030 id->active_area++; 1031 id->active_area = id->active_area % id->nr_areas; 1032} 1033 1034/* 1035 * get_active_entry: 1036 */ 1037static inline debug_entry_t *get_active_entry(debug_info_t *id) 1038{ 1039 return (debug_entry_t *) (((char *) id->areas[id->active_area] 1040 [id->active_pages[id->active_area]]) + 1041 id->active_entries[id->active_area]); 1042} 1043 1044/* Swap debug areas of a and b. */ 1045static void debug_areas_swap(debug_info_t *a, debug_info_t *b) 1046{ 1047 swap(a->nr_areas, b->nr_areas); 1048 swap(a->pages_per_area, b->pages_per_area); 1049 swap(a->areas, b->areas); 1050 swap(a->active_area, b->active_area); 1051 swap(a->active_pages, b->active_pages); 1052 swap(a->active_entries, b->active_entries); 1053} 1054 1055/* Append all debug events in active area from source to destination log. */ 1056static void debug_events_append(debug_info_t *dest, debug_info_t *src) 1057{ 1058 debug_entry_t *from, *to, *last; 1059 1060 if (!src->areas || !dest->areas) 1061 return; 1062 1063 /* Loop over all entries in src, starting with oldest. */ 1064 from = get_active_entry(src); 1065 last = from; 1066 do { 1067 if (from->clock != 0LL) { 1068 to = get_active_entry(dest); 1069 memset(to, 0, dest->entry_size); 1070 memcpy(to, from, min(src->entry_size, 1071 dest->entry_size)); 1072 proceed_active_entry(dest); 1073 } 1074 1075 proceed_active_entry(src); 1076 from = get_active_entry(src); 1077 } while (from != last); 1078} 1079 1080/* 1081 * debug_finish_entry: 1082 * - set timestamp, caller address, cpu number etc. 1083 */ 1084 1085static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active, 1086 int level, int exception) 1087{ 1088 unsigned long timestamp; 1089 union tod_clock clk; 1090 1091 store_tod_clock_ext(&clk); 1092 timestamp = clk.us; 1093 timestamp -= TOD_UNIX_EPOCH >> 12; 1094 active->clock = timestamp; 1095 active->cpu = smp_processor_id(); 1096 active->caller = __builtin_return_address(0); 1097 active->exception = exception; 1098 active->level = level; 1099 proceed_active_entry(id); 1100 if (exception) 1101 proceed_active_area(id); 1102} 1103 1104static int debug_stoppable = 1; 1105static int debug_active = 1; 1106 1107#define CTL_S390DBF_STOPPABLE 5678 1108#define CTL_S390DBF_ACTIVE 5679 1109 1110/* 1111 * proc handler for the running debug_active sysctl 1112 * always allow read, allow write only if debug_stoppable is set or 1113 * if debug_active is already off 1114 */ 1115static int s390dbf_procactive(const struct ctl_table *table, int write, 1116 void *buffer, size_t *lenp, loff_t *ppos) 1117{ 1118 if (!write || debug_stoppable || !debug_active) 1119 return proc_dointvec(table, write, buffer, lenp, ppos); 1120 else 1121 return 0; 1122} 1123 1124static const struct ctl_table s390dbf_table[] = { 1125 { 1126 .procname = "debug_stoppable", 1127 .data = &debug_stoppable, 1128 .maxlen = sizeof(int), 1129 .mode = S_IRUGO | S_IWUSR, 1130 .proc_handler = proc_dointvec, 1131 }, 1132 { 1133 .procname = "debug_active", 1134 .data = &debug_active, 1135 .maxlen = sizeof(int), 1136 .mode = S_IRUGO | S_IWUSR, 1137 .proc_handler = s390dbf_procactive, 1138 }, 1139}; 1140 1141static struct ctl_table_header *s390dbf_sysctl_header; 1142 1143/** 1144 * debug_stop_all() - stops the debug feature if stopping is allowed. 1145 * 1146 * Return: 1147 * - none 1148 * 1149 * Currently used in case of a kernel oops. 1150 */ 1151void debug_stop_all(void) 1152{ 1153 if (debug_stoppable) 1154 debug_active = 0; 1155} 1156EXPORT_SYMBOL(debug_stop_all); 1157 1158/** 1159 * debug_set_critical() - event/exception functions try lock instead of spin. 1160 * 1161 * Return: 1162 * - none 1163 * 1164 * Currently used in case of stopping all CPUs but the current one. 1165 * Once in this state, functions to write a debug entry for an 1166 * event or exception no longer spin on the debug area lock, 1167 * but only try to get it and fail if they do not get the lock. 1168 */ 1169void debug_set_critical(void) 1170{ 1171 debug_critical = 1; 1172} 1173 1174/* 1175 * debug_event_common: 1176 * - write debug entry with given size 1177 */ 1178debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf, 1179 int len) 1180{ 1181 debug_entry_t *active; 1182 unsigned long flags; 1183 1184 if (!debug_active || !id->areas) 1185 return NULL; 1186 if (debug_critical) { 1187 if (!spin_trylock_irqsave(&id->lock, flags)) 1188 return NULL; 1189 } else { 1190 spin_lock_irqsave(&id->lock, flags); 1191 } 1192 do { 1193 active = get_active_entry(id); 1194 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1195 if (len < id->buf_size) 1196 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1197 debug_finish_entry(id, active, level, 0); 1198 len -= id->buf_size; 1199 buf += id->buf_size; 1200 } while (len > 0); 1201 1202 spin_unlock_irqrestore(&id->lock, flags); 1203 return active; 1204} 1205EXPORT_SYMBOL(debug_event_common); 1206 1207/* 1208 * debug_exception_common: 1209 * - write debug entry with given size and switch to next debug area 1210 */ 1211debug_entry_t *debug_exception_common(debug_info_t *id, int level, 1212 const void *buf, int len) 1213{ 1214 debug_entry_t *active; 1215 unsigned long flags; 1216 1217 if (!debug_active || !id->areas) 1218 return NULL; 1219 if (debug_critical) { 1220 if (!spin_trylock_irqsave(&id->lock, flags)) 1221 return NULL; 1222 } else { 1223 spin_lock_irqsave(&id->lock, flags); 1224 } 1225 do { 1226 active = get_active_entry(id); 1227 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size)); 1228 if (len < id->buf_size) 1229 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len); 1230 debug_finish_entry(id, active, level, len <= id->buf_size); 1231 len -= id->buf_size; 1232 buf += id->buf_size; 1233 } while (len > 0); 1234 1235 spin_unlock_irqrestore(&id->lock, flags); 1236 return active; 1237} 1238EXPORT_SYMBOL(debug_exception_common); 1239 1240/* 1241 * counts arguments in format string for sprintf view 1242 */ 1243static inline int debug_count_numargs(char *string) 1244{ 1245 int numargs = 0; 1246 1247 while (*string) { 1248 if (*string++ == '%') 1249 numargs++; 1250 } 1251 return numargs; 1252} 1253 1254/* 1255 * debug_sprintf_event: 1256 */ 1257debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...) 1258{ 1259 debug_sprintf_entry_t *curr_event; 1260 debug_entry_t *active; 1261 unsigned long flags; 1262 int numargs, idx; 1263 va_list ap; 1264 1265 if (!debug_active || !id->areas) 1266 return NULL; 1267 numargs = debug_count_numargs(string); 1268 1269 if (debug_critical) { 1270 if (!spin_trylock_irqsave(&id->lock, flags)) 1271 return NULL; 1272 } else { 1273 spin_lock_irqsave(&id->lock, flags); 1274 } 1275 active = get_active_entry(id); 1276 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active); 1277 va_start(ap, string); 1278 curr_event->string = string; 1279 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1280 curr_event->args[idx] = va_arg(ap, long); 1281 va_end(ap); 1282 debug_finish_entry(id, active, level, 0); 1283 spin_unlock_irqrestore(&id->lock, flags); 1284 1285 return active; 1286} 1287EXPORT_SYMBOL(__debug_sprintf_event); 1288 1289/* 1290 * debug_sprintf_exception: 1291 */ 1292debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...) 1293{ 1294 debug_sprintf_entry_t *curr_event; 1295 debug_entry_t *active; 1296 unsigned long flags; 1297 int numargs, idx; 1298 va_list ap; 1299 1300 if (!debug_active || !id->areas) 1301 return NULL; 1302 1303 numargs = debug_count_numargs(string); 1304 1305 if (debug_critical) { 1306 if (!spin_trylock_irqsave(&id->lock, flags)) 1307 return NULL; 1308 } else { 1309 spin_lock_irqsave(&id->lock, flags); 1310 } 1311 active = get_active_entry(id); 1312 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active); 1313 va_start(ap, string); 1314 curr_event->string = string; 1315 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++) 1316 curr_event->args[idx] = va_arg(ap, long); 1317 va_end(ap); 1318 debug_finish_entry(id, active, level, 1); 1319 spin_unlock_irqrestore(&id->lock, flags); 1320 1321 return active; 1322} 1323EXPORT_SYMBOL(__debug_sprintf_exception); 1324 1325/** 1326 * debug_register_view() - registers new debug view and creates debugfs 1327 * dir entry 1328 * 1329 * @id: handle for debug log 1330 * @view: pointer to debug view struct 1331 * 1332 * Return: 1333 * - 0 : ok 1334 * - < 0: Error 1335 */ 1336int debug_register_view(debug_info_t *id, struct debug_view *view) 1337{ 1338 unsigned long flags; 1339 struct dentry *pde; 1340 umode_t mode; 1341 int rc = 0; 1342 int i; 1343 1344 if (!id) 1345 goto out; 1346 mode = (id->mode | S_IFREG) & ~S_IXUGO; 1347 if (!(view->prolog_proc || view->format_proc || view->header_proc)) 1348 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH); 1349 if (!view->input_proc) 1350 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH); 1351 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry, 1352 id, &debug_file_ops); 1353 spin_lock_irqsave(&id->lock, flags); 1354 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1355 if (!id->views[i]) 1356 break; 1357 } 1358 if (i == DEBUG_MAX_VIEWS) { 1359 rc = -1; 1360 } else { 1361 id->views[i] = view; 1362 id->debugfs_entries[i] = pde; 1363 } 1364 spin_unlock_irqrestore(&id->lock, flags); 1365 if (rc) { 1366 pr_err("Registering view %s/%s would exceed the maximum " 1367 "number of views %i\n", id->name, view->name, i); 1368 debugfs_remove(pde); 1369 } 1370out: 1371 return rc; 1372} 1373EXPORT_SYMBOL(debug_register_view); 1374 1375/** 1376 * debug_unregister_view() - unregisters debug view and removes debugfs 1377 * dir entry 1378 * 1379 * @id: handle for debug log 1380 * @view: pointer to debug view struct 1381 * 1382 * Return: 1383 * - 0 : ok 1384 * - < 0: Error 1385 */ 1386int debug_unregister_view(debug_info_t *id, struct debug_view *view) 1387{ 1388 struct dentry *dentry = NULL; 1389 unsigned long flags; 1390 int i, rc = 0; 1391 1392 if (!id) 1393 goto out; 1394 spin_lock_irqsave(&id->lock, flags); 1395 for (i = 0; i < DEBUG_MAX_VIEWS; i++) { 1396 if (id->views[i] == view) 1397 break; 1398 } 1399 if (i == DEBUG_MAX_VIEWS) { 1400 rc = -1; 1401 } else { 1402 dentry = id->debugfs_entries[i]; 1403 id->views[i] = NULL; 1404 id->debugfs_entries[i] = NULL; 1405 } 1406 spin_unlock_irqrestore(&id->lock, flags); 1407 debugfs_remove(dentry); 1408out: 1409 return rc; 1410} 1411EXPORT_SYMBOL(debug_unregister_view); 1412 1413static inline char *debug_get_user_string(const char __user *user_buf, 1414 size_t user_len) 1415{ 1416 char *buffer; 1417 1418 buffer = memdup_user_nul(user_buf, user_len); 1419 if (IS_ERR(buffer)) 1420 return buffer; 1421 /* got the string, now strip linefeed. */ 1422 if (buffer[user_len - 1] == '\n') 1423 buffer[user_len - 1] = 0; 1424 return buffer; 1425} 1426 1427static inline int debug_get_uint(char *buf) 1428{ 1429 int rc; 1430 1431 buf = skip_spaces(buf); 1432 rc = simple_strtoul(buf, &buf, 10); 1433 if (*buf) 1434 rc = -EINVAL; 1435 return rc; 1436} 1437 1438/* 1439 * functions for debug-views 1440 *********************************** 1441*/ 1442 1443/* 1444 * prints out actual debug level 1445 */ 1446 1447static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view, 1448 char *out_buf, size_t out_buf_size) 1449{ 1450 return scnprintf(out_buf, out_buf_size, "%i\n", id->pages_per_area); 1451} 1452 1453/* 1454 * reads new size (number of pages per debug area) 1455 */ 1456 1457static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view, 1458 struct file *file, const char __user *user_buf, 1459 size_t user_len, loff_t *offset) 1460{ 1461 int rc, new_pages; 1462 char *str; 1463 1464 if (user_len > 0x10000) 1465 user_len = 0x10000; 1466 if (*offset != 0) { 1467 rc = -EPIPE; 1468 goto out; 1469 } 1470 str = debug_get_user_string(user_buf, user_len); 1471 if (IS_ERR(str)) { 1472 rc = PTR_ERR(str); 1473 goto out; 1474 } 1475 new_pages = debug_get_uint(str); 1476 if (new_pages < 0) { 1477 rc = -EINVAL; 1478 goto free_str; 1479 } 1480 rc = debug_set_size(id, id->nr_areas, new_pages); 1481 if (rc != 0) { 1482 rc = -EINVAL; 1483 goto free_str; 1484 } 1485 rc = user_len; 1486free_str: 1487 kfree(str); 1488out: 1489 *offset += user_len; 1490 return rc; /* number of input characters */ 1491} 1492 1493/* 1494 * prints out actual debug level 1495 */ 1496static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view, 1497 char *out_buf, size_t out_buf_size) 1498{ 1499 int rc = 0; 1500 1501 if (id->level == DEBUG_OFF_LEVEL) 1502 rc = scnprintf(out_buf, out_buf_size, "-\n"); 1503 else 1504 rc = scnprintf(out_buf, out_buf_size, "%i\n", id->level); 1505 return rc; 1506} 1507 1508/* 1509 * reads new debug level 1510 */ 1511static int debug_input_level_fn(debug_info_t *id, struct debug_view *view, 1512 struct file *file, const char __user *user_buf, 1513 size_t user_len, loff_t *offset) 1514{ 1515 int rc, new_level; 1516 char *str; 1517 1518 if (user_len > 0x10000) 1519 user_len = 0x10000; 1520 if (*offset != 0) { 1521 rc = -EPIPE; 1522 goto out; 1523 } 1524 str = debug_get_user_string(user_buf, user_len); 1525 if (IS_ERR(str)) { 1526 rc = PTR_ERR(str); 1527 goto out; 1528 } 1529 if (str[0] == '-') { 1530 debug_set_level(id, DEBUG_OFF_LEVEL); 1531 rc = user_len; 1532 goto free_str; 1533 } else { 1534 new_level = debug_get_uint(str); 1535 } 1536 if (new_level < 0) { 1537 pr_warn("%s is not a valid level for a debug feature\n", str); 1538 rc = -EINVAL; 1539 } else { 1540 debug_set_level(id, new_level); 1541 rc = user_len; 1542 } 1543free_str: 1544 kfree(str); 1545out: 1546 *offset += user_len; 1547 return rc; /* number of input characters */ 1548} 1549 1550/* 1551 * flushes debug areas 1552 */ 1553static void debug_flush(debug_info_t *id, int area) 1554{ 1555 unsigned long flags; 1556 int i, j; 1557 1558 if (!id || !id->areas) 1559 return; 1560 spin_lock_irqsave(&id->lock, flags); 1561 if (area == DEBUG_FLUSH_ALL) { 1562 id->active_area = 0; 1563 memset(id->active_entries, 0, id->nr_areas * sizeof(int)); 1564 for (i = 0; i < id->nr_areas; i++) { 1565 id->active_pages[i] = 0; 1566 for (j = 0; j < id->pages_per_area; j++) 1567 memset(id->areas[i][j], 0, PAGE_SIZE); 1568 } 1569 } else if (area >= 0 && area < id->nr_areas) { 1570 id->active_entries[area] = 0; 1571 id->active_pages[area] = 0; 1572 for (i = 0; i < id->pages_per_area; i++) 1573 memset(id->areas[area][i], 0, PAGE_SIZE); 1574 } 1575 spin_unlock_irqrestore(&id->lock, flags); 1576} 1577 1578/* 1579 * view function: flushes debug areas 1580 */ 1581static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view, 1582 struct file *file, const char __user *user_buf, 1583 size_t user_len, loff_t *offset) 1584{ 1585 char input_buf[1]; 1586 int rc = user_len; 1587 1588 if (user_len > 0x10000) 1589 user_len = 0x10000; 1590 if (*offset != 0) { 1591 rc = -EPIPE; 1592 goto out; 1593 } 1594 if (copy_from_user(input_buf, user_buf, 1)) { 1595 rc = -EFAULT; 1596 goto out; 1597 } 1598 if (input_buf[0] == '-') { 1599 debug_flush(id, DEBUG_FLUSH_ALL); 1600 goto out; 1601 } 1602 if (isdigit(input_buf[0])) { 1603 int area = ((int) input_buf[0] - (int) '0'); 1604 1605 debug_flush(id, area); 1606 goto out; 1607 } 1608 1609 pr_info("Flushing debug data failed because %c is not a valid " 1610 "area\n", input_buf[0]); 1611 1612out: 1613 *offset += user_len; 1614 return rc; /* number of input characters */ 1615} 1616 1617/* 1618 * prints debug data in hex/ascii format 1619 */ 1620static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view, 1621 char *out_buf, size_t out_buf_size, const char *in_buf) 1622{ 1623 int i, rc = 0; 1624 1625 for (i = 0; i < id->buf_size; i++) { 1626 rc += scnprintf(out_buf + rc, out_buf_size - rc, 1627 "%02x ", ((unsigned char *)in_buf)[i]); 1628 } 1629 rc += scnprintf(out_buf + rc, out_buf_size - rc, "| "); 1630 for (i = 0; i < id->buf_size; i++) { 1631 unsigned char c = in_buf[i]; 1632 1633 if (isascii(c) && isprint(c)) 1634 rc += scnprintf(out_buf + rc, out_buf_size - rc, "%c", c); 1635 else 1636 rc += scnprintf(out_buf + rc, out_buf_size - rc, "."); 1637 } 1638 rc += scnprintf(out_buf + rc, out_buf_size - rc, "\n"); 1639 return rc; 1640} 1641 1642/* 1643 * prints header for debug entry 1644 */ 1645int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view, 1646 int area, debug_entry_t *entry, char *out_buf, 1647 size_t out_buf_size) 1648{ 1649 unsigned long sec, usec; 1650 unsigned long caller; 1651 unsigned int level; 1652 char *except_str; 1653 int rc = 0; 1654 1655 level = entry->level; 1656 sec = entry->clock; 1657 usec = do_div(sec, USEC_PER_SEC); 1658 1659 if (entry->exception) 1660 except_str = "*"; 1661 else 1662 except_str = "-"; 1663 caller = (unsigned long) entry->caller; 1664 rc += scnprintf(out_buf, out_buf_size, "%02i %011ld:%06lu %1u %1s %04u %px ", 1665 area, sec, usec, level, except_str, 1666 entry->cpu, (void *)caller); 1667 return rc; 1668} 1669EXPORT_SYMBOL(debug_dflt_header_fn); 1670 1671/* 1672 * prints debug data sprintf-formatted: 1673 * debug_sprintf_event/exception calls must be used together with this view 1674 */ 1675 1676#define DEBUG_SPRINTF_MAX_ARGS 10 1677 1678int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view, 1679 char *out_buf, size_t out_buf_size, const char *inbuf) 1680{ 1681 debug_sprintf_entry_t *curr_event = (debug_sprintf_entry_t *)inbuf; 1682 int num_longs, num_used_args = 0, i, rc = 0; 1683 int index[DEBUG_SPRINTF_MAX_ARGS]; 1684 1685 /* count of longs fit into one entry */ 1686 num_longs = id->buf_size / sizeof(long); 1687 1688 if (num_longs < 1) 1689 goto out; /* bufsize of entry too small */ 1690 if (num_longs == 1) { 1691 /* no args, we use only the string */ 1692 rc = strscpy(out_buf, curr_event->string, out_buf_size); 1693 if (rc == -E2BIG) 1694 rc = out_buf_size; 1695 goto out; 1696 } 1697 1698 /* number of arguments used for sprintf (without the format string) */ 1699 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1)); 1700 1701 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int)); 1702 1703 for (i = 0; i < num_used_args; i++) 1704 index[i] = i; 1705 1706 rc = scnprintf(out_buf, out_buf_size, 1707 curr_event->string, curr_event->args[index[0]], 1708 curr_event->args[index[1]], curr_event->args[index[2]], 1709 curr_event->args[index[3]], curr_event->args[index[4]], 1710 curr_event->args[index[5]], curr_event->args[index[6]], 1711 curr_event->args[index[7]], curr_event->args[index[8]], 1712 curr_event->args[index[9]]); 1713out: 1714 return rc; 1715} 1716EXPORT_SYMBOL(debug_sprintf_format_fn); 1717 1718/* 1719 * debug_init: 1720 * - is called exactly once to initialize the debug feature 1721 */ 1722static int __init debug_init(void) 1723{ 1724 s390dbf_sysctl_header = register_sysctl("s390dbf", s390dbf_table); 1725 mutex_lock(&debug_mutex); 1726 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL); 1727 initialized = 1; 1728 mutex_unlock(&debug_mutex); 1729 return 0; 1730} 1731postcore_initcall(debug_init);
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