kern_ktr.c revision 246282
1/*- 2 * Copyright (c) 2000 John Baldwin <jhb@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the author nor the names of any co-contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30/* 31 * This module holds the global variables used by KTR and the ktr_tracepoint() 32 * function that does the actual tracing. 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: head/sys/kern/kern_ktr.c 246282 2013-02-03 09:57:39Z avg $"); 37 38#include "opt_ddb.h" 39#include "opt_ktr.h" 40#include "opt_alq.h" 41 42#include <sys/param.h> 43#include <sys/queue.h> 44#include <sys/alq.h> 45#include <sys/cons.h> 46#include <sys/cpuset.h> 47#include <sys/kernel.h> 48#include <sys/ktr.h> 49#include <sys/libkern.h> 50#include <sys/lock.h> 51#include <sys/malloc.h> 52#include <sys/mutex.h> 53#include <sys/proc.h> 54#include <sys/smp.h> 55#include <sys/sysctl.h> 56#include <sys/systm.h> 57#include <sys/time.h> 58 59#include <machine/cpu.h> 60#ifdef __sparc64__ 61#include <machine/ktr.h> 62#endif 63 64#ifdef DDB 65#include <ddb/ddb.h> 66#include <ddb/db_output.h> 67#endif 68 69#ifndef KTR_BOOT_ENTRIES 70#define KTR_BOOT_ENTRIES 1024 71#endif 72 73#ifndef KTR_ENTRIES 74#define KTR_ENTRIES 1024 75#endif 76 77/* Limit the allocations to something manageable. */ 78#define KTR_ENTRIES_MAX (8 * 1024 * 1024) 79 80#ifndef KTR_MASK 81#define KTR_MASK (0) 82#endif 83 84#ifndef KTR_CPUMASK 85#define KTR_CPUMASK CPUSET_FSET 86#endif 87 88#ifndef KTR_TIME 89#define KTR_TIME get_cyclecount() 90#endif 91 92#ifndef KTR_CPU 93#define KTR_CPU PCPU_GET(cpuid) 94#endif 95 96static MALLOC_DEFINE(M_KTR, "KTR", "KTR"); 97 98FEATURE(ktr, "Kernel support for KTR kernel tracing facility"); 99 100volatile int ktr_idx = 0; 101int ktr_mask = KTR_MASK; 102int ktr_compile = KTR_COMPILE; 103int ktr_entries = KTR_BOOT_ENTRIES; 104int ktr_version = KTR_VERSION; 105struct ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES]; 106struct ktr_entry *ktr_buf = ktr_buf_init; 107cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK); 108static char ktr_cpumask_str[CPUSETBUFSIZ]; 109 110TUNABLE_INT("debug.ktr.mask", &ktr_mask); 111 112TUNABLE_STR("debug.ktr.cpumask", ktr_cpumask_str, sizeof(ktr_cpumask_str)); 113 114static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options"); 115 116SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, 117 &ktr_version, 0, "Version of the KTR interface"); 118 119SYSCTL_UINT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, 120 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel"); 121 122static void 123ktr_cpumask_initializer(void *dummy __unused) 124{ 125 126 /* 127 * TUNABLE_STR() runs with SI_ORDER_MIDDLE priority, thus it must be 128 * already set, if necessary. 129 */ 130 if (ktr_cpumask_str[0] != '\0' && 131 cpusetobj_strscan(&ktr_cpumask, ktr_cpumask_str) == -1) 132 CPU_FILL(&ktr_cpumask); 133} 134SYSINIT(ktr_cpumask_initializer, SI_SUB_TUNABLES, SI_ORDER_ANY, 135 ktr_cpumask_initializer, NULL); 136 137static int 138sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS) 139{ 140 char lktr_cpumask_str[CPUSETBUFSIZ]; 141 cpuset_t imask; 142 int error; 143 144 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask); 145 error = sysctl_handle_string(oidp, lktr_cpumask_str, 146 sizeof(lktr_cpumask_str), req); 147 if (error != 0 || req->newptr == NULL) 148 return (error); 149 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1) 150 return (EINVAL); 151 CPU_COPY(&imask, &ktr_cpumask); 152 153 return (error); 154} 155SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask, 156 CTLFLAG_RW | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0, 157 sysctl_debug_ktr_cpumask, "S", 158 "Bitmask of CPUs on which KTR logging is enabled"); 159 160static int 161sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS) 162{ 163 int clear, error; 164 165 clear = 0; 166 error = sysctl_handle_int(oidp, &clear, 0, req); 167 if (error || !req->newptr) 168 return (error); 169 170 if (clear) { 171 bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries); 172 ktr_idx = 0; 173 } 174 175 return (error); 176} 177SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 178 sysctl_debug_ktr_clear, "I", "Clear KTR Buffer"); 179 180/* 181 * This is a sysctl proc so that it is serialized as !MPSAFE along with 182 * the other ktr sysctl procs. 183 */ 184static int 185sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS) 186{ 187 int mask, error; 188 189 mask = ktr_mask; 190 error = sysctl_handle_int(oidp, &mask, 0, req); 191 if (error || !req->newptr) 192 return (error); 193 ktr_mask = mask; 194 return (error); 195} 196 197SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, CTLTYPE_UINT|CTLFLAG_RW, 0, 0, 198 sysctl_debug_ktr_mask, "IU", 199 "Bitmask of KTR event classes for which logging is enabled"); 200 201#if KTR_ENTRIES != KTR_BOOT_ENTRIES 202/* 203 * A simplified version of sysctl_debug_ktr_entries. 204 * No need to care about SMP, scheduling, etc. 205 */ 206static void 207ktr_entries_initializer(void *dummy __unused) 208{ 209 int mask; 210 211 /* Temporarily disable ktr in case malloc() is being traced. */ 212 mask = ktr_mask; 213 ktr_mask = 0; 214 ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR, 215 M_WAITOK | M_ZERO); 216 ktr_entries = KTR_ENTRIES; 217 ktr_mask = mask; 218} 219SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY, 220 ktr_entries_initializer, NULL); 221#endif 222 223static int 224sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS) 225{ 226 int entries, error, mask; 227 struct ktr_entry *buf, *oldbuf; 228 229 entries = ktr_entries; 230 error = sysctl_handle_int(oidp, &entries, 0, req); 231 if (error || !req->newptr) 232 return (error); 233 if (entries > KTR_ENTRIES_MAX) 234 return (ERANGE); 235 /* Disable ktr temporarily. */ 236 mask = ktr_mask; 237 atomic_store_rel_int(&ktr_mask, 0); 238 /* Wait for threads to go idle. */ 239 if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) { 240 ktr_mask = mask; 241 return (error); 242 } 243 if (ktr_buf != ktr_buf_init) 244 oldbuf = ktr_buf; 245 else 246 oldbuf = NULL; 247 /* Allocate a new buffer. */ 248 buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO); 249 /* Install the new buffer and restart ktr. */ 250 ktr_buf = buf; 251 ktr_entries = entries; 252 ktr_idx = 0; 253 atomic_store_rel_int(&ktr_mask, mask); 254 if (oldbuf != NULL) 255 free(oldbuf, M_KTR); 256 257 return (error); 258} 259 260SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 261 sysctl_debug_ktr_entries, "I", "Number of entries in the KTR buffer"); 262 263#ifdef KTR_VERBOSE 264int ktr_verbose = KTR_VERBOSE; 265TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 266SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, ""); 267#endif 268 269#ifdef KTR_ALQ 270struct alq *ktr_alq; 271char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 272int ktr_alq_cnt = 0; 273int ktr_alq_depth = KTR_ENTRIES; 274int ktr_alq_enabled = 0; 275int ktr_alq_failed = 0; 276int ktr_alq_max = 0; 277 278SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 279 "Maximum number of entries to write"); 280SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 281 "Current number of written entries"); 282SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 283 "Number of times we overran the buffer"); 284SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 285 "Number of items in the write buffer"); 286SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 287 sizeof(ktr_alq_file), "KTR logging file"); 288 289static int 290sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 291{ 292 int error; 293 int enable; 294 295 enable = ktr_alq_enabled; 296 297 error = sysctl_handle_int(oidp, &enable, 0, req); 298 if (error || !req->newptr) 299 return (error); 300 301 if (enable) { 302 if (ktr_alq_enabled) 303 return (0); 304 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 305 req->td->td_ucred, ALQ_DEFAULT_CMODE, 306 sizeof(struct ktr_entry), ktr_alq_depth); 307 if (error == 0) { 308 ktr_alq_cnt = 0; 309 ktr_alq_failed = 0; 310 ktr_alq_enabled = 1; 311 } 312 } else { 313 if (ktr_alq_enabled == 0) 314 return (0); 315 ktr_alq_enabled = 0; 316 alq_close(ktr_alq); 317 ktr_alq = NULL; 318 } 319 320 return (error); 321} 322SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 323 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable, 324 "I", "Enable KTR logging"); 325#endif 326 327void 328ktr_tracepoint(u_int mask, const char *file, int line, const char *format, 329 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 330 u_long arg6) 331{ 332 struct ktr_entry *entry; 333#ifdef KTR_ALQ 334 struct ale *ale = NULL; 335#endif 336 int newindex, saveindex; 337#if defined(KTR_VERBOSE) || defined(KTR_ALQ) 338 struct thread *td; 339#endif 340 int cpu; 341 342 if (panicstr) 343 return; 344 if ((ktr_mask & mask) == 0 || ktr_buf == NULL) 345 return; 346 cpu = KTR_CPU; 347 if (!CPU_ISSET(cpu, &ktr_cpumask)) 348 return; 349#if defined(KTR_VERBOSE) || defined(KTR_ALQ) 350 td = curthread; 351 if (td->td_pflags & TDP_INKTR) 352 return; 353 td->td_pflags |= TDP_INKTR; 354#endif 355#ifdef KTR_ALQ 356 if (ktr_alq_enabled) { 357 if (td->td_critnest == 0 && 358 (td->td_flags & TDF_IDLETD) == 0 && 359 td != ald_thread) { 360 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 361 goto done; 362 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 363 ktr_alq_failed++; 364 goto done; 365 } 366 ktr_alq_cnt++; 367 entry = (struct ktr_entry *)ale->ae_data; 368 } else { 369 goto done; 370 } 371 } else 372#endif 373 { 374 do { 375 saveindex = ktr_idx; 376 newindex = (saveindex + 1) % ktr_entries; 377 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 378 entry = &ktr_buf[saveindex]; 379 } 380 entry->ktr_timestamp = KTR_TIME; 381 entry->ktr_cpu = cpu; 382 entry->ktr_thread = curthread; 383 if (file != NULL) 384 while (strncmp(file, "../", 3) == 0) 385 file += 3; 386 entry->ktr_file = file; 387 entry->ktr_line = line; 388#ifdef KTR_VERBOSE 389 if (ktr_verbose) { 390#ifdef SMP 391 printf("cpu%d ", cpu); 392#endif 393 if (ktr_verbose > 1) { 394 printf("%s.%d\t", entry->ktr_file, 395 entry->ktr_line); 396 } 397 printf(format, arg1, arg2, arg3, arg4, arg5, arg6); 398 printf("\n"); 399 } 400#endif 401 entry->ktr_desc = format; 402 entry->ktr_parms[0] = arg1; 403 entry->ktr_parms[1] = arg2; 404 entry->ktr_parms[2] = arg3; 405 entry->ktr_parms[3] = arg4; 406 entry->ktr_parms[4] = arg5; 407 entry->ktr_parms[5] = arg6; 408#ifdef KTR_ALQ 409 if (ktr_alq_enabled && ale) 410 alq_post(ktr_alq, ale); 411done: 412#endif 413#if defined(KTR_VERBOSE) || defined(KTR_ALQ) 414 td->td_pflags &= ~TDP_INKTR; 415#endif 416} 417 418#ifdef DDB 419 420struct tstate { 421 int cur; 422 int first; 423}; 424static struct tstate tstate; 425static int db_ktr_verbose; 426static int db_mach_vtrace(void); 427 428DB_SHOW_COMMAND(ktr, db_ktr_all) 429{ 430 431 tstate.cur = (ktr_idx - 1) % ktr_entries; 432 tstate.first = -1; 433 db_ktr_verbose = 0; 434 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0; 435 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */ 436 if (strchr(modif, 'a') != NULL) { 437 db_disable_pager(); 438 while (cncheckc() != -1) 439 if (db_mach_vtrace() == 0) 440 break; 441 } else { 442 while (!db_pager_quit) 443 if (db_mach_vtrace() == 0) 444 break; 445 } 446} 447 448static int 449db_mach_vtrace(void) 450{ 451 struct ktr_entry *kp; 452 453 if (tstate.cur == tstate.first || ktr_buf == NULL) { 454 db_printf("--- End of trace buffer ---\n"); 455 return (0); 456 } 457 kp = &ktr_buf[tstate.cur]; 458 459 /* Skip over unused entries. */ 460 if (kp->ktr_desc == NULL) { 461 db_printf("--- End of trace buffer ---\n"); 462 return (0); 463 } 464 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 465#ifdef SMP 466 db_printf(":cpu%d", kp->ktr_cpu); 467#endif 468 db_printf(")"); 469 if (db_ktr_verbose >= 1) { 470 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 471 } 472 if (db_ktr_verbose >= 2) { 473 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 474 } 475 db_printf(": "); 476 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 477 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 478 kp->ktr_parms[5]); 479 db_printf("\n"); 480 481 if (tstate.first == -1) 482 tstate.first = tstate.cur; 483 484 if (--tstate.cur < 0) 485 tstate.cur = ktr_entries - 1; 486 487 return (1); 488} 489 490#endif /* DDB */ 491