libcfs/libcfs/debug.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * libcfs/libcfs/debug.c
  32  *
  33  * Author: Phil Schwan <phil@clusterfs.com>
  34  *
  35  */
  36
  37 # define DEBUG_SUBSYSTEM S_LNET
  38
  39 #include <linux/module.h>
  40 #include <linux/ctype.h>
  41 #include <libcfs/libcfs_string.h>
  42 #include <linux/kthread.h>
  43 #include <linux/stacktrace.h>
  44 #include <linux/utsname.h>
  45 #include <linux/kallsyms.h>
  46 #ifdef HAVE_PANIC_NOTIFIER_H
  47 #include <linux/panic_notifier.h>
  48 #endif
  49 #include "tracefile.h"
  50
  51 static char debug_file_name[1024];
  52
  53 unsigned int libcfs_subsystem_debug = LIBCFS_S_DEFAULT;
  54 EXPORT_SYMBOL(libcfs_subsystem_debug);
  55 module_param(libcfs_subsystem_debug, int, 0644);
  56 MODULE_PARM_DESC(libcfs_subsystem_debug, "Lustre kernel debug subsystem mask");
  57
  58 unsigned int libcfs_debug = LIBCFS_D_DEFAULT;
  59 EXPORT_SYMBOL(libcfs_debug);
  60 module_param(libcfs_debug, int, 0644);
  61 MODULE_PARM_DESC(libcfs_debug, "Lustre kernel debug mask");
  62
  63 static int libcfs_param_debug_mb_set(const char *val,
  64                                      cfs_kernel_param_arg_t *kp)
  65 {
  66         int rc;
  67         unsigned int num;
  68
  69         rc = kstrtouint(val, 0, &num);
  70         if (rc < 0)
  71                 return rc;
  72
  73         num = cfs_trace_set_debug_mb(num);
  74
  75         *((unsigned int *)kp->arg) = num;
  76         num = cfs_trace_get_debug_mb();
  77         if (num)
  78                 /* This value is more precise */
  79                 *((unsigned int *)kp->arg) = num;
  80
  81         return 0;
  82 }
  83
  84 /* While debug_mb setting look like unsigned int, in fact
  85  * it needs quite a bunch of extra processing, so we define special
  86  * debug_mb parameter type with corresponding methods to handle this case
  87  */
  88 static const struct kernel_param_ops param_ops_debug_mb = {
  89         .set = libcfs_param_debug_mb_set,
  90         .get = param_get_uint,
  91 };
  92
  93 #define param_check_debug_mb(name, p) \
  94                 __param_check(name, p, unsigned int)
  95
  96 static unsigned int libcfs_debug_mb;
  97 #ifdef HAVE_KERNEL_PARAM_OPS
  98 module_param(libcfs_debug_mb, debug_mb, 0644);
  99 #else
 100 module_param_call(libcfs_debug_mb, libcfs_param_debug_mb_set, param_get_uint,
 101                   &param_ops_debug_mb, 0644);
 102 #endif
 103 MODULE_PARM_DESC(libcfs_debug_mb, "Total debug buffer size.");
 104
 105 unsigned int libcfs_printk = D_CANTMASK;
 106 module_param(libcfs_printk, uint, 0644);
 107 MODULE_PARM_DESC(libcfs_printk, "Lustre kernel debug console mask");
 108
 109 unsigned int libcfs_console_ratelimit = 1;
 110 module_param(libcfs_console_ratelimit, uint, 0644);
 111 MODULE_PARM_DESC(libcfs_console_ratelimit, "Lustre kernel debug console ratelimit (0 to disable)");
 112
 113 static int param_set_delay_minmax(const char *val,
 114                                   cfs_kernel_param_arg_t *kp,
 115                                   long min, long max)
 116 {
 117         long d;
 118         int sec;
 119         int rc;
 120
 121         rc = kstrtoint(val, 0, &sec);
 122         if (rc)
 123                 return -EINVAL;
 124
 125         /* The sysfs setting is in centiseconds */
 126         d = cfs_time_seconds(sec) / 100;
 127         if (d < min || d > max)
 128                 return -EINVAL;
 129
 130         *((unsigned int *)kp->arg) = d;
 131
 132         return 0;
 133 }
 134
 135 static int param_get_delay(char *buffer, cfs_kernel_param_arg_t *kp)
 136 {
 137         unsigned int d = *(unsigned int *)kp->arg;
 138
 139         param_get_byte(buffer, kp);
 140         return sprintf(buffer, "%lu%c", jiffies_to_msecs(d * 10) / MSEC_PER_SEC,
 141                        strnchr(buffer, PAGE_SIZE, '\n') ? '\n' : '\0');
 142 }
 143
 144 unsigned int libcfs_console_max_delay;
 145 unsigned int libcfs_console_min_delay;
 146
 147 static int param_set_console_max_delay(const char *val,
 148                                        cfs_kernel_param_arg_t *kp)
 149 {
 150         return param_set_delay_minmax(val, kp,
 151                                       libcfs_console_min_delay, INT_MAX);
 152 }
 153
 154 static const struct kernel_param_ops param_ops_console_max_delay = {
 155         .set = param_set_console_max_delay,
 156         .get = param_get_delay,
 157 };
 158
 159 #define param_check_console_max_delay(name, p) \
 160                 __param_check(name, p, unsigned int)
 161
 162 #ifdef HAVE_KERNEL_PARAM_OPS
 163 module_param(libcfs_console_max_delay, console_max_delay, 0644);
 164 #else
 165 module_param_call(libcfs_console_max_delay, param_set_console_max_delay,
 166                   param_get_delay, &param_ops_console_max_delay, 0644);
 167 #endif
 168 MODULE_PARM_DESC(libcfs_console_max_delay, "Lustre kernel debug console max delay (jiffies)");
 169
 170 static int param_set_console_min_delay(const char *val,
 171                                        cfs_kernel_param_arg_t *kp)
 172 {
 173         return param_set_delay_minmax(val, kp,
 174                                       1, libcfs_console_max_delay);
 175 }
 176
 177 static const struct kernel_param_ops param_ops_console_min_delay = {
 178         .set = param_set_console_min_delay,
 179         .get = param_get_delay,
 180 };
 181
 182 #define param_check_console_min_delay(name, p) \
 183                 __param_check(name, p, unsigned int)
 184
 185 #ifdef HAVE_KERNEL_PARAM_OPS
 186 module_param(libcfs_console_min_delay, console_min_delay, 0644);
 187 #else
 188 module_param_call(libcfs_console_min_delay, param_set_console_min_delay,
 189                   param_get_delay, &param_ops_console_min_delay, 0644);
 190 #endif
 191 MODULE_PARM_DESC(libcfs_console_min_delay, "Lustre kernel debug console min delay (jiffies)");
 192
 193 #ifndef HAVE_PARAM_SET_UINT_MINMAX
 194 static int param_set_uint_minmax(const char *val,
 195                                  cfs_kernel_param_arg_t *kp,
 196                                  unsigned int min, unsigned int max)
 197 {
 198         unsigned int num;
 199         int ret;
 200
 201         if (!val)
 202                 return -EINVAL;
 203
 204         ret = kstrtouint(val, 0, &num);
 205         if (ret < 0 || num < min || num > max)
 206                 return -EINVAL;
 207
 208         *((unsigned int *)kp->arg) = num;
 209         return 0;
 210 }
 211 #endif
 212
 213 static int param_set_uintpos(const char *val,
 214                              cfs_kernel_param_arg_t *kp)
 215 {
 216         return param_set_uint_minmax(val, kp, 1, -1);
 217 }
 218
 219 static const struct kernel_param_ops param_ops_uintpos = {
 220         .set = param_set_uintpos,
 221         .get = param_get_uint,
 222 };
 223
 224 #define param_check_uintpos(name, p) \
 225                 __param_check(name, p, unsigned int)
 226
 227 unsigned int libcfs_console_backoff = CDEBUG_DEFAULT_BACKOFF;
 228 #ifdef HAVE_KERNEL_PARAM_OPS
 229 module_param(libcfs_console_backoff, uintpos, 0644);
 230 #else
 231 module_param_call(libcfs_console_backoff, param_set_uintpos, param_get_uint,
 232                   &param_ops_uintpos, 0644);
 233 #endif
 234 MODULE_PARM_DESC(libcfs_console_backoff, "Lustre kernel debug console backoff factor");
 235
 236 unsigned int libcfs_debug_binary = 1;
 237
 238 unsigned int libcfs_catastrophe;
 239 EXPORT_SYMBOL(libcfs_catastrophe);
 240
 241 unsigned int libcfs_watchdog_ratelimit = 300;
 242 EXPORT_SYMBOL(libcfs_watchdog_ratelimit);
 243
 244 unsigned int libcfs_panic_on_lbug = 1;
 245 module_param(libcfs_panic_on_lbug, uint, 0644);
 246 MODULE_PARM_DESC(libcfs_panic_on_lbug, "Lustre kernel panic on LBUG");
 247
 248 atomic64_t libcfs_kmem = ATOMIC64_INIT(0);
 249 EXPORT_SYMBOL(libcfs_kmem);
 250
 251 static DECLARE_COMPLETION(debug_complete);
 252
 253 /* We need to pass a pointer here, but elsewhere this must be a const */
 254 char *libcfs_debug_file_path = LIBCFS_DEBUG_FILE_PATH_DEFAULT;
 255 EXPORT_SYMBOL(libcfs_debug_file_path);
 256 module_param(libcfs_debug_file_path, charp, 0644);
 257 MODULE_PARM_DESC(libcfs_debug_file_path,
 258                  "Path for dumping debug logs, set 'NONE' to prevent log dumping");
 259
 260 int libcfs_panic_in_progress;
 261
 262 /* libcfs_debug_token2mask() expects the returned string in lower-case */
 263 static const char *libcfs_debug_subsys2str(int subsys)
 264 {
 265         static const char *const libcfs_debug_subsystems[] =
 266                 LIBCFS_DEBUG_SUBSYS_NAMES;
 267
 268         if (subsys >= ARRAY_SIZE(libcfs_debug_subsystems))
 269                 return NULL;
 270
 271         return libcfs_debug_subsystems[subsys];
 272 }
 273
 274 /* libcfs_debug_token2mask() expects the returned string in lower-case */
 275 static const char *libcfs_debug_dbg2str(int debug)
 276 {
 277         static const char * const libcfs_debug_masks[] =
 278                 LIBCFS_DEBUG_MASKS_NAMES;
 279
 280         if (debug >= ARRAY_SIZE(libcfs_debug_masks))
 281                 return NULL;
 282
 283         return libcfs_debug_masks[debug];
 284 }
 285
 286 int
 287 libcfs_debug_mask2str(char *str, int size, int mask, int is_subsys)
 288 {
 289         const char *(*fn)(int bit) = is_subsys ? libcfs_debug_subsys2str :
 290                                                  libcfs_debug_dbg2str;
 291         int len = 0;
 292         const char *token;
 293         int i;
 294
 295         if (mask == 0) {                        /* "0" */
 296                 if (size > 0)
 297                         str[0] = '0';
 298                 len = 1;
 299         } else {                                /* space-separated tokens */
 300                 for (i = 0; i < 32; i++) {
 301                         if ((mask & BIT(i)) == 0)
 302                                 continue;
 303
 304                         token = fn(i);
 305                         if (!token)     /* unused bit */
 306                                 continue;
 307
 308                         if (len > 0) {          /* separator? */
 309                                 if (len < size)
 310                                         str[len] = ' ';
 311                                 len++;
 312                         }
 313
 314                         while (*token != 0) {
 315                                 if (len < size)
 316                                         str[len] = *token;
 317                                 token++;
 318                                 len++;
 319                         }
 320                 }
 321         }
 322
 323         /* terminate 'str' */
 324         if (len < size)
 325                 str[len] = 0;
 326         else
 327                 str[size - 1] = 0;
 328
 329         return len;
 330 }
 331
 332 int
 333 libcfs_debug_str2mask(int *mask, const char *str, int is_subsys)
 334 {
 335         const char *(*fn)(int bit) = is_subsys ? libcfs_debug_subsys2str :
 336                                                  libcfs_debug_dbg2str;
 337         int m = 0;
 338         int matched;
 339         int n;
 340         int t;
 341
 342         /* Allow a number for backwards compatibility */
 343         for (n = strlen(str); n > 0; n--)
 344                 if (!isspace(str[n-1]))
 345                         break;
 346         matched = n;
 347         t = sscanf(str, "%i%n", &m, &matched);
 348         if (t >= 1 && matched == n) {
 349                 /* don't print warning for lctl set_param debug=0 or -1 */
 350                 if (m != 0 && m != -1)
 351                         CWARN("You are trying to use a numerical value for the mask - this will be deprecated in a future release.\n");
 352                 *mask = m;
 353                 return 0;
 354         }
 355
 356         return cfs_str2mask(str, fn, mask, is_subsys ? 0 : D_CANTMASK, ~0,
 357                             is_subsys ? LIBCFS_S_DEFAULT : LIBCFS_D_DEFAULT);
 358 }
 359
 360 char lnet_debug_log_upcall[1024] = "/usr/lib/lustre/lnet_debug_log_upcall";
 361
 362 /* Upcall function once a Lustre log has been dumped.
 363  *
 364  * @file        path of the dumped log
 365  */
 366 static void libcfs_run_debug_log_upcall(char *file)
 367 {
 368         char *argv[3];
 369         int rc;
 370         static const char * const envp[] = {
 371                 "HOME=/",
 372                 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
 373                 NULL
 374         };
 375
 376         ENTRY;
 377         argv[0] = lnet_debug_log_upcall;
 378
 379         LASSERTF(file, "called on a null filename\n");
 380         argv[1] = file; /* only need to pass the path of the file */
 381
 382         argv[2] = NULL;
 383
 384         rc = call_usermodehelper(argv[0], argv, (char **)envp, 1);
 385         if (rc < 0 && rc != -ENOENT) {
 386                 CERROR("Error %d invoking LNET debug log upcall %s %s; check /sys/kernel/debug/lnet/debug_log_upcall\n",
 387                        rc, argv[0], argv[1]);
 388         } else {
 389                 CDEBUG(D_HA, "Invoked LNET debug log upcall %s %s\n",
 390                        argv[0], argv[1]);
 391         }
 392 }
 393
 394 /**
 395  * Dump Lustre log to ::debug_file_path by calling tracefile_dump_all_pages()
 396  */
 397 static void libcfs_debug_dumplog_internal(void *arg)
 398 {
 399         static time64_t last_dump_time;
 400         time64_t current_time;
 401
 402         current_time = ktime_get_real_seconds();
 403
 404         if (strncmp(libcfs_debug_file_path, "NONE", 4) != 0 &&
 405             current_time > last_dump_time) {
 406                 last_dump_time = current_time;
 407                 snprintf(debug_file_name, sizeof(debug_file_name) - 1,
 408                          "%s.%lld.%ld", libcfs_debug_file_path,
 409                          (s64)current_time, (uintptr_t)arg);
 410                 pr_alert("LustreError: dumping log to %s\n", debug_file_name);
 411                 cfs_tracefile_dump_all_pages(debug_file_name);
 412                 libcfs_run_debug_log_upcall(debug_file_name);
 413         }
 414 }
 415
 416 static int libcfs_debug_dumplog_thread(void *arg)
 417 {
 418         libcfs_debug_dumplog_internal(arg);
 419         complete(&debug_complete);
 420         return 0;
 421 }
 422
 423 static DEFINE_MUTEX(libcfs_debug_dumplog_lock);
 424
 425 void libcfs_debug_dumplog(void)
 426 {
 427         struct task_struct *dumper;
 428
 429         ENTRY;
 430
 431         if (mutex_trylock(&libcfs_debug_dumplog_lock) == 0)
 432                 return;
 433
 434         /* If a previous call was interrupted, debug_complete->done
 435          * might be elevated, and so we won't actually wait here.
 436          * So we reinit the completion to ensure we wait for
 437          * one thread to complete, though it might not be the one
 438          * we start if there are overlaping thread.
 439          */
 440         reinit_completion(&debug_complete);
 441         dumper = kthread_run(libcfs_debug_dumplog_thread,
 442                              (void *)(long)current->pid,
 443                              "libcfs_debug_dumper");
 444         if (IS_ERR(dumper))
 445                 pr_err("LustreError: cannot start log dump thread: rc = %ld\n",
 446                        PTR_ERR(dumper));
 447         else
 448                 wait_for_completion_interruptible(&debug_complete);
 449
 450         mutex_unlock(&libcfs_debug_dumplog_lock);
 451 }
 452 EXPORT_SYMBOL(libcfs_debug_dumplog);
 453
 454 void __noreturn lbug_with_loc(struct libcfs_debug_msg_data *msgdata)
 455 {
 456         libcfs_catastrophe = 1;
 457         libcfs_debug_msg(msgdata, "LBUG\n");
 458
 459         if (in_interrupt()) {
 460                 panic("LBUG in interrupt.\n");
 461                 /* not reached */
 462         }
 463
 464         dump_stack();
 465         if (libcfs_panic_on_lbug)
 466                 panic("LBUG");
 467         else
 468                 libcfs_debug_dumplog();
 469         set_current_state(TASK_UNINTERRUPTIBLE);
 470         while (1)
 471                 schedule();
 472 }
 473 EXPORT_SYMBOL(lbug_with_loc);
 474
 475 #ifdef CONFIG_STACKTRACE
 476
 477 #ifndef HAVE_SAVE_STACK_TRACE_TSK
 478 #define save_stack_trace_tsk(tsk, trace)                                       \
 479 do {                                                                           \
 480         if (tsk == current)                                                    \
 481                 save_stack_trace(trace);                                       \
 482         else                                                                   \
 483                 pr_info("No stack, save_stack_trace_tsk() not exported\n");    \
 484 } while (0)
 485 #endif
 486
 487 static void cfs_print_stack_trace(unsigned long *entries, unsigned int nr)
 488 {
 489         unsigned int i;
 490
 491         /* Prefer %pB for backtraced symbolic names since it was added in:
 492          * Linux v2.6.38-6557-g0f77a8d37825
 493          * vsprintf: Introduce %pB format specifier
 494          */
 495         for (i = 0; i < nr; i++)
 496                 pr_info("[<0>] %pB\n", (void *)entries[i]);
 497 }
 498
 499 #define MAX_ST_ENTRIES  100
 500 static DEFINE_SPINLOCK(st_lock);
 501
 502 static void libcfs_call_trace(struct task_struct *tsk)
 503 {
 504         static unsigned long entries[MAX_ST_ENTRIES];
 505 #ifdef CONFIG_ARCH_STACKWALK
 506         unsigned int nr_entries;
 507
 508         spin_lock(&st_lock);
 509         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 510                 init_utsname()->release, init_utsname()->version);
 511         pr_info("Call Trace TBD:\n");
 512         nr_entries = cfs_stack_trace_save_tsk(tsk, entries, MAX_ST_ENTRIES, 0);
 513         cfs_print_stack_trace(entries, nr_entries);
 514         spin_unlock(&st_lock);
 515 #else
 516         struct stack_trace trace;
 517
 518         trace.nr_entries = 0;
 519         trace.max_entries = MAX_ST_ENTRIES;
 520         trace.entries = entries;
 521         trace.skip = 0;
 522
 523         spin_lock(&st_lock);
 524         pr_info("Pid: %d, comm: %.20s %s %s\n", tsk->pid, tsk->comm,
 525                 init_utsname()->release, init_utsname()->version);
 526         pr_info("Call Trace:\n");
 527         save_stack_trace_tsk(tsk, &trace);
 528         cfs_print_stack_trace(trace.entries, trace.nr_entries);
 529         spin_unlock(&st_lock);
 530 #endif
 531 }
 532
 533 #else /* !CONFIG_STACKTRACE */
 534
 535 #ifdef CONFIG_X86
 536 #include <linux/nmi.h>
 537 #include <asm/stacktrace.h>
 538
 539 #ifdef HAVE_STACKTRACE_OPS
 540 static int print_trace_stack(void *data, char *name)
 541 {
 542         printk(" <%s> ", name);
 543         return 0;
 544 }
 545
 546 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 547 static int
 548 #else
 549 static void
 550 #endif
 551 print_trace_address(void *data, unsigned long addr, int reliable)
 552 {
 553         char fmt[32];
 554
 555         touch_nmi_watchdog();
 556         sprintf(fmt, " [<%016lx>] %s%%s\n", addr, reliable ? "" : "? ");
 557         __print_symbol(fmt, addr);
 558 #ifdef STACKTRACE_OPS_ADDRESS_RETURN_INT
 559         return 0;
 560 #endif
 561 }
 562
 563 static const struct stacktrace_ops print_trace_ops = {
 564         .stack          = print_trace_stack,
 565         .address        = print_trace_address,
 566         .walk_stack     = print_context_stack,
 567 };
 568 #endif /* HAVE_STACKTRACE_OPS */
 569
 570 static void libcfs_call_trace(struct task_struct *tsk)
 571 {
 572 #ifdef HAVE_STACKTRACE_OPS
 573         printk("Pid: %d, comm: %.20s\n", tsk->pid, tsk->comm);
 574         printk("\nCall Trace:\n");
 575         dump_trace(tsk, NULL, NULL, 0, &print_trace_ops, NULL);
 576         printk("\n");
 577 #else /* !HAVE_STACKTRACE_OPS */
 578         if (tsk == current)
 579                 dump_stack();
 580         else
 581                 CWARN("can't show stack: kernel doesn't export show_task\n");
 582 #endif /* HAVE_STACKTRACE_OPS */
 583 }
 584
 585 #else /* !CONFIG_X86 */
 586
 587 static void libcfs_call_trace(struct task_struct *tsk)
 588 {
 589         if (tsk == current)
 590                 dump_stack();
 591         else
 592                 CWARN("can't show stack: kernel doesn't export show_task\n");
 593 }
 594
 595 #endif /* CONFIG_X86 */
 596
 597 #endif /* CONFIG_STACKTRACE */
 598
 599 void libcfs_debug_dumpstack(struct task_struct *tsk)
 600 {
 601         libcfs_call_trace(tsk ?: current);
 602 }
 603 EXPORT_SYMBOL(libcfs_debug_dumpstack);
 604
 605 static int panic_notifier(struct notifier_block *self, unsigned long unused1,
 606                           void *unused2)
 607 {
 608         if (libcfs_panic_in_progress)
 609                 return 0;
 610
 611         libcfs_panic_in_progress = 1;
 612         mb();
 613
 614 #ifdef LNET_DUMP_ON_PANIC
 615         /* This is currently disabled because it spews far too much to the
 616          * console on the rare cases it is ever triggered. */
 617
 618         if (in_interrupt()) {
 619                 cfs_trace_debug_print();
 620         } else {
 621                 libcfs_debug_dumplog_internal((void *)(long)current->pid);
 622         }
 623 #endif
 624         return 0;
 625 }
 626
 627 static struct notifier_block libcfs_panic_notifier = {
 628         .notifier_call          = panic_notifier,
 629         .next                   = NULL,
 630         .priority               = 10000,
 631 };
 632
 633 static void libcfs_register_panic_notifier(void)
 634 {
 635         atomic_notifier_chain_register(&panic_notifier_list,
 636                                        &libcfs_panic_notifier);
 637 }
 638
 639 static void libcfs_unregister_panic_notifier(void)
 640 {
 641         atomic_notifier_chain_unregister(&panic_notifier_list,
 642                                          &libcfs_panic_notifier);
 643 }
 644
 645 static bool debug_started;
 646
 647 int libcfs_debug_init(unsigned long bufsize)
 648 {
 649         unsigned int max = libcfs_debug_mb;
 650         int rc = 0;
 651
 652         if (debug_started)
 653                 return 0;
 654
 655         debug_started = true;
 656         if (libcfs_console_max_delay <= 0 || /* not set by user or */
 657             libcfs_console_min_delay <= 0 || /* set to invalid values */
 658             libcfs_console_min_delay >= libcfs_console_max_delay) {
 659                 libcfs_console_max_delay = CDEBUG_DEFAULT_MAX_DELAY;
 660                 libcfs_console_min_delay = CDEBUG_DEFAULT_MIN_DELAY;
 661         }
 662
 663         /* If libcfs_debug_mb is uninitialized then just make the
 664          * total buffers smp_num_cpus * TCD_MAX_PAGES
 665          */
 666         if (max < num_possible_cpus())
 667                 max = TCD_MAX_PAGES;
 668         else
 669                 max <<= (20 - PAGE_SHIFT);
 670
 671         rc = cfs_tracefile_init(max);
 672         if (rc)
 673                 return rc;
 674
 675         libcfs_register_panic_notifier();
 676         kernel_param_lock(THIS_MODULE);
 677         libcfs_debug_mb = cfs_trace_get_debug_mb();
 678         kernel_param_unlock(THIS_MODULE);
 679         return rc;
 680 }
 681
 682 int libcfs_debug_cleanup(void)
 683 {
 684         libcfs_unregister_panic_notifier();
 685         kernel_param_lock(THIS_MODULE);
 686         cfs_tracefile_exit();
 687         kernel_param_unlock(THIS_MODULE);
 688         debug_started = false;
 689         return 0;
 690 }
 691
 692 int libcfs_debug_clear_buffer(void)
 693 {
 694         cfs_trace_flush_pages();
 695         return 0;
 696 }
 697
 698 /* Debug markers, although printed by S_LNET should not be be marked as such. */
 699 #undef DEBUG_SUBSYSTEM
 700 #define DEBUG_SUBSYSTEM S_UNDEFINED
 701 int libcfs_debug_mark_buffer(const char *text)
 702 {
 703         CDEBUG(D_TRACE,
 704                "**************************************************\n");
 705         LCONSOLE(D_WARNING, "DEBUG MARKER: %s\n", text);
 706         CDEBUG(D_TRACE,
 707                "**************************************************\n");
 708
 709         return 0;
 710 }
 711
 712 #undef DEBUG_SUBSYSTEM
 713 #define DEBUG_SUBSYSTEM S_LNET