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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 /* 28 * This module holds the global variables used by KTR and the ktr_tracepoint() 29 * function that does the actual tracing. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_ddb.h" 36 #include "opt_ktr.h" 37 #include "opt_alq.h" 38 39 #include <sys/param.h> 40 #include <sys/queue.h> 41 #include <sys/alq.h> 42 #include <sys/cons.h> 43 #include <sys/cpuset.h> 44 #include <sys/kernel.h> 45 #include <sys/ktr.h> 46 #include <sys/libkern.h> 47 #include <sys/lock.h> 48 #include <sys/malloc.h> 49 #include <sys/mutex.h> 50 #include <sys/proc.h> 51 #include <sys/smp.h> 52 #include <sys/sysctl.h> 53 #include <sys/systm.h> 54 #include <sys/time.h> 55 56 #include <machine/cpu.h> 57 #ifdef __sparc64__ 58 #include <machine/ktr.h> 59 #endif 60 61 #ifdef DDB 62 #include <ddb/ddb.h> 63 #include <ddb/db_output.h> 64 #endif 65 66 #ifndef KTR_BOOT_ENTRIES 67 #define KTR_BOOT_ENTRIES 1024 68 #endif 69 70 #ifndef KTR_ENTRIES 71 #define KTR_ENTRIES 1024 72 #endif 73 74 /* Limit the allocations to something manageable. */ 75 #define KTR_ENTRIES_MAX (8 * 1024 * 1024) 76 77 #ifndef KTR_MASK 78 #define KTR_MASK (0) 79 #endif 80 81 #ifndef KTR_CPUMASK 82 #define KTR_CPUMASK CPUSET_FSET 83 #endif 84 85 #ifndef KTR_TIME 86 #define KTR_TIME get_cyclecount() 87 #endif 88 89 #ifndef KTR_CPU 90 #define KTR_CPU PCPU_GET(cpuid) 91 #endif 92 93 static MALLOC_DEFINE(M_KTR, "KTR", "KTR"); 94 95 FEATURE(ktr, "Kernel support for KTR kernel tracing facility"); 96 97 volatile int ktr_idx = 0; 98 int ktr_mask = KTR_MASK; 99 int ktr_compile = KTR_COMPILE; 100 int ktr_entries = KTR_BOOT_ENTRIES; 101 int ktr_version = KTR_VERSION; 102 struct ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES]; 103 struct ktr_entry *ktr_buf = ktr_buf_init; 104 cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK); 105 static char ktr_cpumask_str[CPUSETBUFSIZ]; 106 107 TUNABLE_INT("debug.ktr.mask", &ktr_mask); 108 109 TUNABLE_STR("debug.ktr.cpumask", ktr_cpumask_str, sizeof(ktr_cpumask_str)); 110 111 static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options"); 112 113 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, 114 &ktr_version, 0, "Version of the KTR interface"); 115 116 SYSCTL_UINT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, 117 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel"); 118 119 static void 120 ktr_cpumask_initializer(void *dummy __unused) 121 { 122 123 /* 124 * TUNABLE_STR() runs with SI_ORDER_MIDDLE priority, thus it must be 125 * already set, if necessary. 126 */ 127 if (ktr_cpumask_str[0] != '\0' && 128 cpusetobj_strscan(&ktr_cpumask, ktr_cpumask_str) == -1) 129 CPU_FILL(&ktr_cpumask); 130 } 131 SYSINIT(ktr_cpumask_initializer, SI_SUB_TUNABLES, SI_ORDER_ANY, 132 ktr_cpumask_initializer, NULL); 133 134 static int 135 sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS) 136 { 137 char lktr_cpumask_str[CPUSETBUFSIZ]; 138 cpuset_t imask; 139 int error; 140 141 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask); 142 error = sysctl_handle_string(oidp, lktr_cpumask_str, 143 sizeof(lktr_cpumask_str), req); 144 if (error != 0 || req->newptr == NULL) 145 return (error); 146 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1) 147 return (EINVAL); 148 CPU_COPY(&imask, &ktr_cpumask); 149 150 return (error); 151 } 152 SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask, 153 CTLFLAG_RW | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0, 154 sysctl_debug_ktr_cpumask, "S", 155 "Bitmask of CPUs on which KTR logging is enabled"); 156 157 static int 158 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS) 159 { 160 int clear, error; 161 162 clear = 0; 163 error = sysctl_handle_int(oidp, &clear, 0, req); 164 if (error || !req->newptr) 165 return (error); 166 167 if (clear) { 168 bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries); 169 ktr_idx = 0; 170 } 171 172 return (error); 173 } 174 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 175 sysctl_debug_ktr_clear, "I", "Clear KTR Buffer"); 176 177 /* 178 * This is a sysctl proc so that it is serialized as !MPSAFE along with 179 * the other ktr sysctl procs. 180 */ 181 static int 182 sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS) 183 { 184 int mask, error; 185 186 mask = ktr_mask; 187 error = sysctl_handle_int(oidp, &mask, 0, req); 188 if (error || !req->newptr) 189 return (error); 190 ktr_mask = mask; 191 return (error); 192 } 193 194 SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, CTLTYPE_UINT|CTLFLAG_RW, 0, 0, 195 sysctl_debug_ktr_mask, "IU", 196 "Bitmask of KTR event classes for which logging is enabled"); 197 198 #if KTR_ENTRIES > KTR_BOOT_ENTRIES 199 /* 200 * A simplified version of sysctl_debug_ktr_entries. 201 * No need to care about SMP, scheduling, etc. 202 */ 203 static void 204 ktr_entries_initializer(void *dummy __unused) 205 { 206 int mask; 207 208 /* Temporarily disable ktr in case malloc() is being traced. */ 209 mask = ktr_mask; 210 ktr_mask = 0; 211 ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR, 212 M_WAITOK | M_ZERO); 213 memcpy(ktr_buf, ktr_buf_init + ktr_idx, 214 (KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf)); 215 if (ktr_idx != 0) { 216 memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init, 217 ktr_idx * sizeof(*ktr_buf)); 218 ktr_idx = KTR_BOOT_ENTRIES; 219 } 220 ktr_entries = KTR_ENTRIES; 221 ktr_mask = mask; 222 } 223 SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY, 224 ktr_entries_initializer, NULL); 225 #endif 226 227 static int 228 sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS) 229 { 230 int entries, error, mask; 231 struct ktr_entry *buf, *oldbuf; 232 233 entries = ktr_entries; 234 error = sysctl_handle_int(oidp, &entries, 0, req); 235 if (error || !req->newptr) 236 return (error); 237 if (entries > KTR_ENTRIES_MAX) 238 return (ERANGE); 239 /* Disable ktr temporarily. */ 240 mask = ktr_mask; 241 atomic_store_rel_int(&ktr_mask, 0); 242 /* Wait for threads to go idle. */ 243 if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) { 244 ktr_mask = mask; 245 return (error); 246 } 247 if (ktr_buf != ktr_buf_init) 248 oldbuf = ktr_buf; 249 else 250 oldbuf = NULL; 251 /* Allocate a new buffer. */ 252 buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO); 253 /* Install the new buffer and restart ktr. */ 254 ktr_buf = buf; 255 ktr_entries = entries; 256 ktr_idx = 0; 257 atomic_store_rel_int(&ktr_mask, mask); 258 if (oldbuf != NULL) 259 free(oldbuf, M_KTR); 260 261 return (error); 262 } 263 264 SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 265 sysctl_debug_ktr_entries, "I", "Number of entries in the KTR buffer"); 266 267 #ifdef KTR_VERBOSE 268 int ktr_verbose = KTR_VERBOSE; 269 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 270 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, ""); 271 #endif 272 273 #ifdef KTR_ALQ 274 struct alq *ktr_alq; 275 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 276 int ktr_alq_cnt = 0; 277 int ktr_alq_depth = KTR_ENTRIES; 278 int ktr_alq_enabled = 0; 279 int ktr_alq_failed = 0; 280 int ktr_alq_max = 0; 281 282 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 283 "Maximum number of entries to write"); 284 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 285 "Current number of written entries"); 286 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 287 "Number of times we overran the buffer"); 288 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 289 "Number of items in the write buffer"); 290 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 291 sizeof(ktr_alq_file), "KTR logging file"); 292 293 static int 294 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 295 { 296 int error; 297 int enable; 298 299 enable = ktr_alq_enabled; 300 301 error = sysctl_handle_int(oidp, &enable, 0, req); 302 if (error || !req->newptr) 303 return (error); 304 305 if (enable) { 306 if (ktr_alq_enabled) 307 return (0); 308 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 309 req->td->td_ucred, ALQ_DEFAULT_CMODE, 310 sizeof(struct ktr_entry), ktr_alq_depth); 311 if (error == 0) { 312 ktr_alq_cnt = 0; 313 ktr_alq_failed = 0; 314 ktr_alq_enabled = 1; 315 } 316 } else { 317 if (ktr_alq_enabled == 0) 318 return (0); 319 ktr_alq_enabled = 0; 320 alq_close(ktr_alq); 321 ktr_alq = NULL; 322 } 323 324 return (error); 325 } 326 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 327 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable, 328 "I", "Enable KTR logging"); 329 #endif 330 331 void 332 ktr_tracepoint(u_int mask, const char *file, int line, const char *format, 333 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 334 u_long arg6) 335 { 336 struct ktr_entry *entry; 337 #ifdef KTR_ALQ 338 struct ale *ale = NULL; 339 #endif 340 int newindex, saveindex; 341 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 342 struct thread *td; 343 #endif 344 int cpu; 345 346 if (panicstr) 347 return; 348 if ((ktr_mask & mask) == 0 || ktr_buf == NULL) 349 return; 350 cpu = KTR_CPU; 351 if (!CPU_ISSET(cpu, &ktr_cpumask)) 352 return; 353 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 354 td = curthread; 355 if (td->td_pflags & TDP_INKTR) 356 return; 357 td->td_pflags |= TDP_INKTR; 358 #endif 359 #ifdef KTR_ALQ 360 if (ktr_alq_enabled) { 361 if (td->td_critnest == 0 && 362 (td->td_flags & TDF_IDLETD) == 0 && 363 td != ald_thread) { 364 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 365 goto done; 366 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 367 ktr_alq_failed++; 368 goto done; 369 } 370 ktr_alq_cnt++; 371 entry = (struct ktr_entry *)ale->ae_data; 372 } else { 373 goto done; 374 } 375 } else 376 #endif 377 { 378 do { 379 saveindex = ktr_idx; 380 newindex = (saveindex + 1) % ktr_entries; 381 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 382 entry = &ktr_buf[saveindex]; 383 } 384 entry->ktr_timestamp = KTR_TIME; 385 entry->ktr_cpu = cpu; 386 entry->ktr_thread = curthread; 387 if (file != NULL) 388 while (strncmp(file, "../", 3) == 0) 389 file += 3; 390 entry->ktr_file = file; 391 entry->ktr_line = line; 392 #ifdef KTR_VERBOSE 393 if (ktr_verbose) { 394 #ifdef SMP 395 printf("cpu%d ", cpu); 396 #endif 397 if (ktr_verbose > 1) { 398 printf("%s.%d\t", entry->ktr_file, 399 entry->ktr_line); 400 } 401 printf(format, arg1, arg2, arg3, arg4, arg5, arg6); 402 printf("\n"); 403 } 404 #endif 405 entry->ktr_desc = format; 406 entry->ktr_parms[0] = arg1; 407 entry->ktr_parms[1] = arg2; 408 entry->ktr_parms[2] = arg3; 409 entry->ktr_parms[3] = arg4; 410 entry->ktr_parms[4] = arg5; 411 entry->ktr_parms[5] = arg6; 412 #ifdef KTR_ALQ 413 if (ktr_alq_enabled && ale) 414 alq_post(ktr_alq, ale); 415 done: 416 #endif 417 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 418 td->td_pflags &= ~TDP_INKTR; 419 #endif 420 } 421 422 #ifdef DDB 423 424 struct tstate { 425 int cur; 426 int first; 427 }; 428 static struct tstate tstate; 429 static int db_ktr_verbose; 430 static int db_mach_vtrace(void); 431 432 DB_SHOW_COMMAND(ktr, db_ktr_all) 433 { 434 435 tstate.cur = (ktr_idx - 1) % ktr_entries; 436 tstate.first = -1; 437 db_ktr_verbose = 0; 438 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0; 439 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */ 440 if (strchr(modif, 'a') != NULL) { 441 db_disable_pager(); 442 while (cncheckc() != -1) 443 if (db_mach_vtrace() == 0) 444 break; 445 } else { 446 while (!db_pager_quit) 447 if (db_mach_vtrace() == 0) 448 break; 449 } 450 } 451 452 static int 453 db_mach_vtrace(void) 454 { 455 struct ktr_entry *kp; 456 457 if (tstate.cur == tstate.first || ktr_buf == NULL) { 458 db_printf("--- End of trace buffer ---\n"); 459 return (0); 460 } 461 kp = &ktr_buf[tstate.cur]; 462 463 /* Skip over unused entries. */ 464 if (kp->ktr_desc == NULL) { 465 db_printf("--- End of trace buffer ---\n"); 466 return (0); 467 } 468 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 469 #ifdef SMP 470 db_printf(":cpu%d", kp->ktr_cpu); 471 #endif 472 db_printf(")"); 473 if (db_ktr_verbose >= 1) { 474 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 475 } 476 if (db_ktr_verbose >= 2) { 477 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 478 } 479 db_printf(": "); 480 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 481 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 482 kp->ktr_parms[5]); 483 db_printf("\n"); 484 485 if (tstate.first == -1) 486 tstate.first = tstate.cur; 487 488 if (--tstate.cur < 0) 489 tstate.cur = ktr_entries - 1; 490 491 return (1); 492 } 493 494 #endif /* DDB */ 495