1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2000 John Baldwin <jhb@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * This module holds the global variables used by KTR and the ktr_tracepoint() 30 * function that does the actual tracing. 31 */ 32 33 #include <sys/cdefs.h> 34 #include "opt_ddb.h" 35 #include "opt_ktr.h" 36 #include "opt_alq.h" 37 38 #include <sys/param.h> 39 #include <sys/queue.h> 40 #include <sys/alq.h> 41 #include <sys/cons.h> 42 #include <sys/cpuset.h> 43 #include <sys/kdb.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 58 #ifdef DDB 59 #include <ddb/ddb.h> 60 #include <ddb/db_output.h> 61 #endif 62 63 #ifndef KTR_BOOT_ENTRIES 64 #define KTR_BOOT_ENTRIES 1024 65 #endif 66 67 #ifndef KTR_ENTRIES 68 #define KTR_ENTRIES 1024 69 #endif 70 71 /* Limit the allocations to something manageable. */ 72 #define KTR_ENTRIES_MAX (8 * 1024 * 1024) 73 74 #ifndef KTR_MASK 75 #define KTR_MASK (0) 76 #endif 77 78 #ifndef KTR_CPUMASK 79 #define KTR_CPUMASK CPUSET_FSET 80 #endif 81 82 #ifndef KTR_TIME 83 #define KTR_TIME get_cyclecount() 84 #endif 85 86 #ifndef KTR_CPU 87 #define KTR_CPU PCPU_GET(cpuid) 88 #endif 89 90 static MALLOC_DEFINE(M_KTR, "KTR", "KTR"); 91 92 FEATURE(ktr, "Kernel support for KTR kernel tracing facility"); 93 94 volatile int ktr_idx = 0; 95 uint64_t ktr_mask = KTR_MASK; 96 uint64_t ktr_compile = KTR_COMPILE; 97 int ktr_entries = KTR_BOOT_ENTRIES; 98 int ktr_version = KTR_VERSION; 99 struct ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES]; 100 struct ktr_entry *ktr_buf = ktr_buf_init; 101 cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK); 102 103 static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 104 "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, 153 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, 154 sysctl_debug_ktr_clear, "I", 155 "Clear KTR Buffer"); 156 157 /* 158 * This is a sysctl proc so that it is serialized as !MPSAFE along with 159 * the other ktr sysctl procs. 160 */ 161 static int 162 sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS) 163 { 164 uint64_t mask; 165 int error; 166 167 mask = ktr_mask; 168 error = sysctl_handle_64(oidp, &mask, 0, req); 169 if (error || !req->newptr) 170 return (error); 171 ktr_mask = mask; 172 return (error); 173 } 174 175 SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, 176 CTLTYPE_U64 | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 177 0, 0, sysctl_debug_ktr_mask, "QU", 178 "Bitmask of KTR event classes for which logging is enabled"); 179 180 #if KTR_ENTRIES > KTR_BOOT_ENTRIES 181 /* 182 * A simplified version of sysctl_debug_ktr_entries. 183 * No need to care about SMP, scheduling, etc. 184 */ 185 static void 186 ktr_entries_initializer(void *dummy __unused) 187 { 188 uint64_t mask; 189 190 /* Temporarily disable ktr in case malloc() is being traced. */ 191 mask = ktr_mask; 192 ktr_mask = 0; 193 ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR, 194 M_WAITOK | M_ZERO); 195 memcpy(ktr_buf, ktr_buf_init + ktr_idx, 196 (KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf)); 197 if (ktr_idx != 0) { 198 memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init, 199 ktr_idx * sizeof(*ktr_buf)); 200 ktr_idx = KTR_BOOT_ENTRIES; 201 } 202 ktr_entries = KTR_ENTRIES; 203 ktr_mask = mask; 204 } 205 SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY, 206 ktr_entries_initializer, NULL); 207 #endif 208 209 static int 210 sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS) 211 { 212 uint64_t mask; 213 int entries, error; 214 struct ktr_entry *buf, *oldbuf; 215 216 entries = ktr_entries; 217 error = sysctl_handle_int(oidp, &entries, 0, req); 218 if (error || !req->newptr) 219 return (error); 220 if (entries > KTR_ENTRIES_MAX) 221 return (ERANGE); 222 /* Disable ktr temporarily. */ 223 mask = ktr_mask; 224 ktr_mask = 0; 225 /* Wait for threads to go idle. */ 226 if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) { 227 ktr_mask = mask; 228 return (error); 229 } 230 if (ktr_buf != ktr_buf_init) 231 oldbuf = ktr_buf; 232 else 233 oldbuf = NULL; 234 /* Allocate a new buffer. */ 235 buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO); 236 /* Install the new buffer and restart ktr. */ 237 ktr_buf = buf; 238 ktr_entries = entries; 239 ktr_idx = 0; 240 ktr_mask = mask; 241 if (oldbuf != NULL) 242 free(oldbuf, M_KTR); 243 244 return (error); 245 } 246 247 SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, 248 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 249 0, 0, sysctl_debug_ktr_entries, "I", 250 "Number of entries in the KTR buffer"); 251 252 #ifdef KTR_VERBOSE 253 int ktr_verbose = KTR_VERBOSE; 254 #else 255 int ktr_verbose = 0; 256 #endif 257 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 258 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RWTUN, &ktr_verbose, 0, 259 "Print extra info when logging to the console"); 260 261 #ifdef KTR_ALQ 262 struct alq *ktr_alq; 263 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 264 int ktr_alq_cnt = 0; 265 int ktr_alq_depth = KTR_ENTRIES; 266 int ktr_alq_enabled = 0; 267 int ktr_alq_failed = 0; 268 int ktr_alq_max = 0; 269 270 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 271 "Maximum number of entries to write"); 272 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 273 "Current number of written entries"); 274 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 275 "Number of times we overran the buffer"); 276 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 277 "Number of items in the write buffer"); 278 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 279 sizeof(ktr_alq_file), "KTR logging file"); 280 281 static int 282 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 283 { 284 int error; 285 int enable; 286 287 enable = ktr_alq_enabled; 288 289 error = sysctl_handle_int(oidp, &enable, 0, req); 290 if (error || !req->newptr) 291 return (error); 292 293 if (enable) { 294 if (ktr_alq_enabled) 295 return (0); 296 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 297 req->td->td_ucred, ALQ_DEFAULT_CMODE, 298 sizeof(struct ktr_entry), ktr_alq_depth); 299 if (error == 0) { 300 ktr_alq_cnt = 0; 301 ktr_alq_failed = 0; 302 ktr_alq_enabled = 1; 303 } 304 } else { 305 if (ktr_alq_enabled == 0) 306 return (0); 307 ktr_alq_enabled = 0; 308 alq_close(ktr_alq); 309 ktr_alq = NULL; 310 } 311 312 return (error); 313 } 314 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 315 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, 316 sysctl_debug_ktr_alq_enable, "I", 317 "Enable KTR logging"); 318 #endif 319 320 void 321 ktr_tracepoint(uint64_t mask, const char *file, int line, const char *format, 322 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 323 u_long arg6) 324 { 325 struct ktr_entry *entry; 326 #ifdef KTR_ALQ 327 struct ale *ale = NULL; 328 #endif 329 int newindex, saveindex; 330 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 331 struct thread *td; 332 #endif 333 int cpu; 334 335 if (KERNEL_PANICKED() || kdb_active) 336 return; 337 if ((ktr_mask & mask) == 0 || ktr_buf == NULL) 338 return; 339 cpu = KTR_CPU; 340 if (!CPU_ISSET(cpu, &ktr_cpumask)) 341 return; 342 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 343 td = curthread; 344 if (td->td_pflags & TDP_INKTR) 345 return; 346 td->td_pflags |= TDP_INKTR; 347 #endif 348 #ifdef KTR_ALQ 349 if (ktr_alq_enabled) { 350 if (td->td_critnest == 0 && 351 (TD_IS_IDLETHREAD(td)) == 0 && 352 td != ald_thread) { 353 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 354 goto done; 355 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 356 ktr_alq_failed++; 357 goto done; 358 } 359 ktr_alq_cnt++; 360 entry = (struct ktr_entry *)ale->ae_data; 361 } else { 362 goto done; 363 } 364 } else 365 #endif 366 { 367 do { 368 saveindex = ktr_idx; 369 newindex = (saveindex + 1) % ktr_entries; 370 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 371 entry = &ktr_buf[saveindex]; 372 } 373 entry->ktr_timestamp = KTR_TIME; 374 entry->ktr_cpu = cpu; 375 entry->ktr_thread = curthread; 376 if (file != NULL) 377 while (strncmp(file, "../", 3) == 0) 378 file += 3; 379 entry->ktr_file = file; 380 entry->ktr_line = line; 381 if (ktr_verbose) { 382 #ifdef SMP 383 printf("cpu%d ", cpu); 384 #endif 385 if (ktr_verbose > 1) { 386 printf("%s.%d\t", entry->ktr_file, 387 entry->ktr_line); 388 } 389 printf(format, arg1, arg2, arg3, arg4, arg5, arg6); 390 printf("\n"); 391 } 392 entry->ktr_desc = format; 393 entry->ktr_parms[0] = arg1; 394 entry->ktr_parms[1] = arg2; 395 entry->ktr_parms[2] = arg3; 396 entry->ktr_parms[3] = arg4; 397 entry->ktr_parms[4] = arg5; 398 entry->ktr_parms[5] = arg6; 399 #ifdef KTR_ALQ 400 if (ktr_alq_enabled && ale) 401 alq_post(ktr_alq, ale); 402 done: 403 #endif 404 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 405 td->td_pflags &= ~TDP_INKTR; 406 #endif 407 } 408 409 #ifdef DDB 410 411 struct tstate { 412 int cur; 413 int first; 414 }; 415 static struct tstate tstate; 416 static int db_ktr_verbose; 417 static int db_mach_vtrace(void); 418 419 DB_SHOW_COMMAND_FLAGS(ktr, db_ktr_all, DB_CMD_MEMSAFE) 420 { 421 422 tstate.cur = (ktr_idx - 1) % ktr_entries; 423 tstate.first = -1; 424 db_ktr_verbose = 0; 425 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0; 426 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestamp please */ 427 if (strchr(modif, 'a') != NULL) { 428 db_disable_pager(); 429 while (cncheckc() == -1) 430 if (db_mach_vtrace() == 0) 431 break; 432 } else { 433 while (!db_pager_quit) 434 if (db_mach_vtrace() == 0) 435 break; 436 } 437 } 438 439 static int 440 db_mach_vtrace(void) 441 { 442 struct ktr_entry *kp; 443 444 if (tstate.cur == tstate.first || ktr_buf == NULL) { 445 db_printf("--- End of trace buffer ---\n"); 446 return (0); 447 } 448 kp = &ktr_buf[tstate.cur]; 449 450 /* Skip over unused entries. */ 451 if (kp->ktr_desc == NULL) { 452 db_printf("--- End of trace buffer ---\n"); 453 return (0); 454 } 455 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 456 #ifdef SMP 457 db_printf(":cpu%d", kp->ktr_cpu); 458 #endif 459 db_printf(")"); 460 if (db_ktr_verbose >= 1) { 461 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 462 } 463 if (db_ktr_verbose >= 2) { 464 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 465 } 466 db_printf(": "); 467 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 468 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 469 kp->ktr_parms[5]); 470 db_printf("\n"); 471 472 if (tstate.first == -1) 473 tstate.first = tstate.cur; 474 475 if (--tstate.cur < 0) 476 tstate.cur = ktr_entries - 1; 477 478 return (1); 479 } 480 481 #endif /* DDB */ 482