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/kdb.h> 45 #include <sys/kernel.h> 46 #include <sys/ktr.h> 47 #include <sys/libkern.h> 48 #include <sys/lock.h> 49 #include <sys/malloc.h> 50 #include <sys/mutex.h> 51 #include <sys/proc.h> 52 #include <sys/smp.h> 53 #include <sys/sysctl.h> 54 #include <sys/systm.h> 55 #include <sys/time.h> 56 57 #include <machine/cpu.h> 58 59 #ifdef DDB 60 #include <ddb/ddb.h> 61 #include <ddb/db_output.h> 62 #endif 63 64 #ifndef KTR_BOOT_ENTRIES 65 #define KTR_BOOT_ENTRIES 1024 66 #endif 67 68 #ifndef KTR_ENTRIES 69 #define KTR_ENTRIES 1024 70 #endif 71 72 /* Limit the allocations to something manageable. */ 73 #define KTR_ENTRIES_MAX (8 * 1024 * 1024) 74 75 #ifndef KTR_MASK 76 #define KTR_MASK (0) 77 #endif 78 79 #ifndef KTR_CPUMASK 80 #define KTR_CPUMASK CPUSET_FSET 81 #endif 82 83 #ifndef KTR_TIME 84 #define KTR_TIME get_cyclecount() 85 #endif 86 87 #ifndef KTR_CPU 88 #define KTR_CPU PCPU_GET(cpuid) 89 #endif 90 91 static MALLOC_DEFINE(M_KTR, "KTR", "KTR"); 92 93 FEATURE(ktr, "Kernel support for KTR kernel tracing facility"); 94 95 volatile int ktr_idx = 0; 96 uint64_t ktr_mask = KTR_MASK; 97 uint64_t ktr_compile = KTR_COMPILE; 98 int ktr_entries = KTR_BOOT_ENTRIES; 99 int ktr_version = KTR_VERSION; 100 struct ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES]; 101 struct ktr_entry *ktr_buf = ktr_buf_init; 102 cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK); 103 104 static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options"); 105 106 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, 107 &ktr_version, 0, "Version of the KTR interface"); 108 109 SYSCTL_UQUAD(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, 110 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel"); 111 112 static int 113 sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS) 114 { 115 char lktr_cpumask_str[CPUSETBUFSIZ]; 116 cpuset_t imask; 117 int error; 118 119 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask); 120 error = sysctl_handle_string(oidp, lktr_cpumask_str, 121 sizeof(lktr_cpumask_str), req); 122 if (error != 0 || req->newptr == NULL) 123 return (error); 124 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1) 125 return (EINVAL); 126 CPU_COPY(&imask, &ktr_cpumask); 127 128 return (error); 129 } 130 SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask, 131 CTLFLAG_RWTUN | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0, 132 sysctl_debug_ktr_cpumask, "S", 133 "Bitmask of CPUs on which KTR logging is enabled"); 134 135 static int 136 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS) 137 { 138 int clear, error; 139 140 clear = 0; 141 error = sysctl_handle_int(oidp, &clear, 0, req); 142 if (error || !req->newptr) 143 return (error); 144 145 if (clear) { 146 bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries); 147 ktr_idx = 0; 148 } 149 150 return (error); 151 } 152 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 153 sysctl_debug_ktr_clear, "I", "Clear KTR Buffer"); 154 155 /* 156 * This is a sysctl proc so that it is serialized as !MPSAFE along with 157 * the other ktr sysctl procs. 158 */ 159 static int 160 sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS) 161 { 162 uint64_t mask; 163 int error; 164 165 mask = ktr_mask; 166 error = sysctl_handle_64(oidp, &mask, 0, req); 167 if (error || !req->newptr) 168 return (error); 169 ktr_mask = mask; 170 return (error); 171 } 172 173 SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, CTLTYPE_U64 | CTLFLAG_RWTUN, 0, 0, 174 sysctl_debug_ktr_mask, "QU", 175 "Bitmask of KTR event classes for which logging is enabled"); 176 177 #if KTR_ENTRIES > KTR_BOOT_ENTRIES 178 /* 179 * A simplified version of sysctl_debug_ktr_entries. 180 * No need to care about SMP, scheduling, etc. 181 */ 182 static void 183 ktr_entries_initializer(void *dummy __unused) 184 { 185 uint64_t mask; 186 187 /* Temporarily disable ktr in case malloc() is being traced. */ 188 mask = ktr_mask; 189 ktr_mask = 0; 190 ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR, 191 M_WAITOK | M_ZERO); 192 memcpy(ktr_buf, ktr_buf_init + ktr_idx, 193 (KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf)); 194 if (ktr_idx != 0) { 195 memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init, 196 ktr_idx * sizeof(*ktr_buf)); 197 ktr_idx = KTR_BOOT_ENTRIES; 198 } 199 ktr_entries = KTR_ENTRIES; 200 ktr_mask = mask; 201 } 202 SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY, 203 ktr_entries_initializer, NULL); 204 #endif 205 206 static int 207 sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS) 208 { 209 uint64_t mask; 210 int entries, error; 211 struct ktr_entry *buf, *oldbuf; 212 213 entries = ktr_entries; 214 error = sysctl_handle_int(oidp, &entries, 0, req); 215 if (error || !req->newptr) 216 return (error); 217 if (entries > KTR_ENTRIES_MAX) 218 return (ERANGE); 219 /* Disable ktr temporarily. */ 220 mask = ktr_mask; 221 ktr_mask = 0; 222 /* Wait for threads to go idle. */ 223 if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) { 224 ktr_mask = mask; 225 return (error); 226 } 227 if (ktr_buf != ktr_buf_init) 228 oldbuf = ktr_buf; 229 else 230 oldbuf = NULL; 231 /* Allocate a new buffer. */ 232 buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO); 233 /* Install the new buffer and restart ktr. */ 234 ktr_buf = buf; 235 ktr_entries = entries; 236 ktr_idx = 0; 237 ktr_mask = mask; 238 if (oldbuf != NULL) 239 free(oldbuf, M_KTR); 240 241 return (error); 242 } 243 244 SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 245 sysctl_debug_ktr_entries, "I", "Number of entries in the KTR buffer"); 246 247 #ifdef KTR_VERBOSE 248 int ktr_verbose = KTR_VERBOSE; 249 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 250 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, ""); 251 #endif 252 253 #ifdef KTR_ALQ 254 struct alq *ktr_alq; 255 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 256 int ktr_alq_cnt = 0; 257 int ktr_alq_depth = KTR_ENTRIES; 258 int ktr_alq_enabled = 0; 259 int ktr_alq_failed = 0; 260 int ktr_alq_max = 0; 261 262 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 263 "Maximum number of entries to write"); 264 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 265 "Current number of written entries"); 266 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 267 "Number of times we overran the buffer"); 268 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 269 "Number of items in the write buffer"); 270 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 271 sizeof(ktr_alq_file), "KTR logging file"); 272 273 static int 274 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 275 { 276 int error; 277 int enable; 278 279 enable = ktr_alq_enabled; 280 281 error = sysctl_handle_int(oidp, &enable, 0, req); 282 if (error || !req->newptr) 283 return (error); 284 285 if (enable) { 286 if (ktr_alq_enabled) 287 return (0); 288 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 289 req->td->td_ucred, ALQ_DEFAULT_CMODE, 290 sizeof(struct ktr_entry), ktr_alq_depth); 291 if (error == 0) { 292 ktr_alq_cnt = 0; 293 ktr_alq_failed = 0; 294 ktr_alq_enabled = 1; 295 } 296 } else { 297 if (ktr_alq_enabled == 0) 298 return (0); 299 ktr_alq_enabled = 0; 300 alq_close(ktr_alq); 301 ktr_alq = NULL; 302 } 303 304 return (error); 305 } 306 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 307 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable, 308 "I", "Enable KTR logging"); 309 #endif 310 311 void 312 ktr_tracepoint(uint64_t mask, const char *file, int line, const char *format, 313 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 314 u_long arg6) 315 { 316 struct ktr_entry *entry; 317 #ifdef KTR_ALQ 318 struct ale *ale = NULL; 319 #endif 320 int newindex, saveindex; 321 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 322 struct thread *td; 323 #endif 324 int cpu; 325 326 if (panicstr || kdb_active) 327 return; 328 if ((ktr_mask & mask) == 0 || ktr_buf == NULL) 329 return; 330 cpu = KTR_CPU; 331 if (!CPU_ISSET(cpu, &ktr_cpumask)) 332 return; 333 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 334 td = curthread; 335 if (td->td_pflags & TDP_INKTR) 336 return; 337 td->td_pflags |= TDP_INKTR; 338 #endif 339 #ifdef KTR_ALQ 340 if (ktr_alq_enabled) { 341 if (td->td_critnest == 0 && 342 (td->td_flags & TDF_IDLETD) == 0 && 343 td != ald_thread) { 344 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 345 goto done; 346 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 347 ktr_alq_failed++; 348 goto done; 349 } 350 ktr_alq_cnt++; 351 entry = (struct ktr_entry *)ale->ae_data; 352 } else { 353 goto done; 354 } 355 } else 356 #endif 357 { 358 do { 359 saveindex = ktr_idx; 360 newindex = (saveindex + 1) % ktr_entries; 361 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 362 entry = &ktr_buf[saveindex]; 363 } 364 entry->ktr_timestamp = KTR_TIME; 365 entry->ktr_cpu = cpu; 366 entry->ktr_thread = curthread; 367 if (file != NULL) 368 while (strncmp(file, "../", 3) == 0) 369 file += 3; 370 entry->ktr_file = file; 371 entry->ktr_line = line; 372 #ifdef KTR_VERBOSE 373 if (ktr_verbose) { 374 #ifdef SMP 375 printf("cpu%d ", cpu); 376 #endif 377 if (ktr_verbose > 1) { 378 printf("%s.%d\t", entry->ktr_file, 379 entry->ktr_line); 380 } 381 printf(format, arg1, arg2, arg3, arg4, arg5, arg6); 382 printf("\n"); 383 } 384 #endif 385 entry->ktr_desc = format; 386 entry->ktr_parms[0] = arg1; 387 entry->ktr_parms[1] = arg2; 388 entry->ktr_parms[2] = arg3; 389 entry->ktr_parms[3] = arg4; 390 entry->ktr_parms[4] = arg5; 391 entry->ktr_parms[5] = arg6; 392 #ifdef KTR_ALQ 393 if (ktr_alq_enabled && ale) 394 alq_post(ktr_alq, ale); 395 done: 396 #endif 397 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 398 td->td_pflags &= ~TDP_INKTR; 399 #endif 400 } 401 402 #ifdef DDB 403 404 struct tstate { 405 int cur; 406 int first; 407 }; 408 static struct tstate tstate; 409 static int db_ktr_verbose; 410 static int db_mach_vtrace(void); 411 412 DB_SHOW_COMMAND(ktr, db_ktr_all) 413 { 414 415 tstate.cur = (ktr_idx - 1) % ktr_entries; 416 tstate.first = -1; 417 db_ktr_verbose = 0; 418 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0; 419 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */ 420 if (strchr(modif, 'a') != NULL) { 421 db_disable_pager(); 422 while (cncheckc() == -1) 423 if (db_mach_vtrace() == 0) 424 break; 425 } else { 426 while (!db_pager_quit) 427 if (db_mach_vtrace() == 0) 428 break; 429 } 430 } 431 432 static int 433 db_mach_vtrace(void) 434 { 435 struct ktr_entry *kp; 436 437 if (tstate.cur == tstate.first || ktr_buf == NULL) { 438 db_printf("--- End of trace buffer ---\n"); 439 return (0); 440 } 441 kp = &ktr_buf[tstate.cur]; 442 443 /* Skip over unused entries. */ 444 if (kp->ktr_desc == NULL) { 445 db_printf("--- End of trace buffer ---\n"); 446 return (0); 447 } 448 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 449 #ifdef SMP 450 db_printf(":cpu%d", kp->ktr_cpu); 451 #endif 452 db_printf(")"); 453 if (db_ktr_verbose >= 1) { 454 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 455 } 456 if (db_ktr_verbose >= 2) { 457 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 458 } 459 db_printf(": "); 460 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 461 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 462 kp->ktr_parms[5]); 463 db_printf("\n"); 464 465 if (tstate.first == -1) 466 tstate.first = tstate.cur; 467 468 if (--tstate.cur < 0) 469 tstate.cur = ktr_entries - 1; 470 471 return (1); 472 } 473 474 #endif /* DDB */ 475