1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 35 36 #include "opt_ddb.h" 37 #include "opt_ktr.h" 38 #include "opt_alq.h" 39 40 #include <sys/param.h> 41 #include <sys/queue.h> 42 #include <sys/alq.h> 43 #include <sys/cons.h> 44 #include <sys/cpuset.h> 45 #include <sys/kdb.h> 46 #include <sys/kernel.h> 47 #include <sys/ktr.h> 48 #include <sys/libkern.h> 49 #include <sys/lock.h> 50 #include <sys/malloc.h> 51 #include <sys/mutex.h> 52 #include <sys/proc.h> 53 #include <sys/smp.h> 54 #include <sys/sysctl.h> 55 #include <sys/systm.h> 56 #include <sys/time.h> 57 58 #include <machine/cpu.h> 59 60 #ifdef DDB 61 #include <ddb/ddb.h> 62 #include <ddb/db_output.h> 63 #endif 64 65 #ifndef KTR_BOOT_ENTRIES 66 #define KTR_BOOT_ENTRIES 1024 67 #endif 68 69 #ifndef KTR_ENTRIES 70 #define KTR_ENTRIES 1024 71 #endif 72 73 /* Limit the allocations to something manageable. */ 74 #define KTR_ENTRIES_MAX (8 * 1024 * 1024) 75 76 #ifndef KTR_MASK 77 #define KTR_MASK (0) 78 #endif 79 80 #ifndef KTR_CPUMASK 81 #define KTR_CPUMASK CPUSET_FSET 82 #endif 83 84 #ifndef KTR_TIME 85 #define KTR_TIME get_cyclecount() 86 #endif 87 88 #ifndef KTR_CPU 89 #define KTR_CPU PCPU_GET(cpuid) 90 #endif 91 92 static MALLOC_DEFINE(M_KTR, "KTR", "KTR"); 93 94 FEATURE(ktr, "Kernel support for KTR kernel tracing facility"); 95 96 volatile int ktr_idx = 0; 97 uint64_t ktr_mask = KTR_MASK; 98 uint64_t ktr_compile = KTR_COMPILE; 99 int ktr_entries = KTR_BOOT_ENTRIES; 100 int ktr_version = KTR_VERSION; 101 struct ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES]; 102 struct ktr_entry *ktr_buf = ktr_buf_init; 103 cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK); 104 105 static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 106 "KTR options"); 107 108 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, 109 &ktr_version, 0, "Version of the KTR interface"); 110 111 SYSCTL_UQUAD(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, 112 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel"); 113 114 static int 115 sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS) 116 { 117 char lktr_cpumask_str[CPUSETBUFSIZ]; 118 cpuset_t imask; 119 int error; 120 121 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask); 122 error = sysctl_handle_string(oidp, lktr_cpumask_str, 123 sizeof(lktr_cpumask_str), req); 124 if (error != 0 || req->newptr == NULL) 125 return (error); 126 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1) 127 return (EINVAL); 128 CPU_COPY(&imask, &ktr_cpumask); 129 130 return (error); 131 } 132 SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask, 133 CTLFLAG_RWTUN | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0, 134 sysctl_debug_ktr_cpumask, "S", 135 "Bitmask of CPUs on which KTR logging is enabled"); 136 137 static int 138 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS) 139 { 140 int clear, error; 141 142 clear = 0; 143 error = sysctl_handle_int(oidp, &clear, 0, req); 144 if (error || !req->newptr) 145 return (error); 146 147 if (clear) { 148 bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries); 149 ktr_idx = 0; 150 } 151 152 return (error); 153 } 154 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, 155 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, 156 sysctl_debug_ktr_clear, "I", 157 "Clear KTR Buffer"); 158 159 /* 160 * This is a sysctl proc so that it is serialized as !MPSAFE along with 161 * the other ktr sysctl procs. 162 */ 163 static int 164 sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS) 165 { 166 uint64_t mask; 167 int error; 168 169 mask = ktr_mask; 170 error = sysctl_handle_64(oidp, &mask, 0, req); 171 if (error || !req->newptr) 172 return (error); 173 ktr_mask = mask; 174 return (error); 175 } 176 177 SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, 178 CTLTYPE_U64 | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 179 0, 0, sysctl_debug_ktr_mask, "QU", 180 "Bitmask of KTR event classes for which logging is enabled"); 181 182 #if KTR_ENTRIES > KTR_BOOT_ENTRIES 183 /* 184 * A simplified version of sysctl_debug_ktr_entries. 185 * No need to care about SMP, scheduling, etc. 186 */ 187 static void 188 ktr_entries_initializer(void *dummy __unused) 189 { 190 uint64_t mask; 191 192 /* Temporarily disable ktr in case malloc() is being traced. */ 193 mask = ktr_mask; 194 ktr_mask = 0; 195 ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR, 196 M_WAITOK | M_ZERO); 197 memcpy(ktr_buf, ktr_buf_init + ktr_idx, 198 (KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf)); 199 if (ktr_idx != 0) { 200 memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init, 201 ktr_idx * sizeof(*ktr_buf)); 202 ktr_idx = KTR_BOOT_ENTRIES; 203 } 204 ktr_entries = KTR_ENTRIES; 205 ktr_mask = mask; 206 } 207 SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY, 208 ktr_entries_initializer, NULL); 209 #endif 210 211 static int 212 sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS) 213 { 214 uint64_t mask; 215 int entries, error; 216 struct ktr_entry *buf, *oldbuf; 217 218 entries = ktr_entries; 219 error = sysctl_handle_int(oidp, &entries, 0, req); 220 if (error || !req->newptr) 221 return (error); 222 if (entries > KTR_ENTRIES_MAX) 223 return (ERANGE); 224 /* Disable ktr temporarily. */ 225 mask = ktr_mask; 226 ktr_mask = 0; 227 /* Wait for threads to go idle. */ 228 if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) { 229 ktr_mask = mask; 230 return (error); 231 } 232 if (ktr_buf != ktr_buf_init) 233 oldbuf = ktr_buf; 234 else 235 oldbuf = NULL; 236 /* Allocate a new buffer. */ 237 buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO); 238 /* Install the new buffer and restart ktr. */ 239 ktr_buf = buf; 240 ktr_entries = entries; 241 ktr_idx = 0; 242 ktr_mask = mask; 243 if (oldbuf != NULL) 244 free(oldbuf, M_KTR); 245 246 return (error); 247 } 248 249 SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, 250 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 251 0, 0, sysctl_debug_ktr_entries, "I", 252 "Number of entries in the KTR buffer"); 253 254 #ifdef KTR_VERBOSE 255 int ktr_verbose = KTR_VERBOSE; 256 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 257 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, ""); 258 #endif 259 260 #ifdef KTR_ALQ 261 struct alq *ktr_alq; 262 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 263 int ktr_alq_cnt = 0; 264 int ktr_alq_depth = KTR_ENTRIES; 265 int ktr_alq_enabled = 0; 266 int ktr_alq_failed = 0; 267 int ktr_alq_max = 0; 268 269 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 270 "Maximum number of entries to write"); 271 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 272 "Current number of written entries"); 273 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 274 "Number of times we overran the buffer"); 275 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 276 "Number of items in the write buffer"); 277 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 278 sizeof(ktr_alq_file), "KTR logging file"); 279 280 static int 281 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 282 { 283 int error; 284 int enable; 285 286 enable = ktr_alq_enabled; 287 288 error = sysctl_handle_int(oidp, &enable, 0, req); 289 if (error || !req->newptr) 290 return (error); 291 292 if (enable) { 293 if (ktr_alq_enabled) 294 return (0); 295 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 296 req->td->td_ucred, ALQ_DEFAULT_CMODE, 297 sizeof(struct ktr_entry), ktr_alq_depth); 298 if (error == 0) { 299 ktr_alq_cnt = 0; 300 ktr_alq_failed = 0; 301 ktr_alq_enabled = 1; 302 } 303 } else { 304 if (ktr_alq_enabled == 0) 305 return (0); 306 ktr_alq_enabled = 0; 307 alq_close(ktr_alq); 308 ktr_alq = NULL; 309 } 310 311 return (error); 312 } 313 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 314 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, 315 sysctl_debug_ktr_alq_enable, "I", 316 "Enable KTR logging"); 317 #endif 318 319 void 320 ktr_tracepoint(uint64_t mask, const char *file, int line, const char *format, 321 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 322 u_long arg6) 323 { 324 struct ktr_entry *entry; 325 #ifdef KTR_ALQ 326 struct ale *ale = NULL; 327 #endif 328 int newindex, saveindex; 329 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 330 struct thread *td; 331 #endif 332 int cpu; 333 334 if (KERNEL_PANICKED() || kdb_active) 335 return; 336 if ((ktr_mask & mask) == 0 || ktr_buf == NULL) 337 return; 338 cpu = KTR_CPU; 339 if (!CPU_ISSET(cpu, &ktr_cpumask)) 340 return; 341 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 342 td = curthread; 343 if (td->td_pflags & TDP_INKTR) 344 return; 345 td->td_pflags |= TDP_INKTR; 346 #endif 347 #ifdef KTR_ALQ 348 if (ktr_alq_enabled) { 349 if (td->td_critnest == 0 && 350 (TD_IS_IDLETHREAD(td)) == 0 && 351 td != ald_thread) { 352 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 353 goto done; 354 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 355 ktr_alq_failed++; 356 goto done; 357 } 358 ktr_alq_cnt++; 359 entry = (struct ktr_entry *)ale->ae_data; 360 } else { 361 goto done; 362 } 363 } else 364 #endif 365 { 366 do { 367 saveindex = ktr_idx; 368 newindex = (saveindex + 1) % ktr_entries; 369 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 370 entry = &ktr_buf[saveindex]; 371 } 372 entry->ktr_timestamp = KTR_TIME; 373 entry->ktr_cpu = cpu; 374 entry->ktr_thread = curthread; 375 if (file != NULL) 376 while (strncmp(file, "../", 3) == 0) 377 file += 3; 378 entry->ktr_file = file; 379 entry->ktr_line = line; 380 #ifdef KTR_VERBOSE 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 #endif 393 entry->ktr_desc = format; 394 entry->ktr_parms[0] = arg1; 395 entry->ktr_parms[1] = arg2; 396 entry->ktr_parms[2] = arg3; 397 entry->ktr_parms[3] = arg4; 398 entry->ktr_parms[4] = arg5; 399 entry->ktr_parms[5] = arg6; 400 #ifdef KTR_ALQ 401 if (ktr_alq_enabled && ale) 402 alq_post(ktr_alq, ale); 403 done: 404 #endif 405 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 406 td->td_pflags &= ~TDP_INKTR; 407 #endif 408 } 409 410 #ifdef DDB 411 412 struct tstate { 413 int cur; 414 int first; 415 }; 416 static struct tstate tstate; 417 static int db_ktr_verbose; 418 static int db_mach_vtrace(void); 419 420 DB_SHOW_COMMAND(ktr, db_ktr_all) 421 { 422 423 tstate.cur = (ktr_idx - 1) % ktr_entries; 424 tstate.first = -1; 425 db_ktr_verbose = 0; 426 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0; 427 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestamp please */ 428 if (strchr(modif, 'a') != NULL) { 429 db_disable_pager(); 430 while (cncheckc() == -1) 431 if (db_mach_vtrace() == 0) 432 break; 433 } else { 434 while (!db_pager_quit) 435 if (db_mach_vtrace() == 0) 436 break; 437 } 438 } 439 440 static int 441 db_mach_vtrace(void) 442 { 443 struct ktr_entry *kp; 444 445 if (tstate.cur == tstate.first || ktr_buf == NULL) { 446 db_printf("--- End of trace buffer ---\n"); 447 return (0); 448 } 449 kp = &ktr_buf[tstate.cur]; 450 451 /* Skip over unused entries. */ 452 if (kp->ktr_desc == NULL) { 453 db_printf("--- End of trace buffer ---\n"); 454 return (0); 455 } 456 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 457 #ifdef SMP 458 db_printf(":cpu%d", kp->ktr_cpu); 459 #endif 460 db_printf(")"); 461 if (db_ktr_verbose >= 1) { 462 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 463 } 464 if (db_ktr_verbose >= 2) { 465 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 466 } 467 db_printf(": "); 468 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 469 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 470 kp->ktr_parms[5]); 471 db_printf("\n"); 472 473 if (tstate.first == -1) 474 tstate.first = tstate.cur; 475 476 if (--tstate.cur < 0) 477 tstate.cur = ktr_entries - 1; 478 479 return (1); 480 } 481 482 #endif /* DDB */ 483