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 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 255 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, ""); 256 #endif 257 258 #ifdef KTR_ALQ 259 struct alq *ktr_alq; 260 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 261 int ktr_alq_cnt = 0; 262 int ktr_alq_depth = KTR_ENTRIES; 263 int ktr_alq_enabled = 0; 264 int ktr_alq_failed = 0; 265 int ktr_alq_max = 0; 266 267 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 268 "Maximum number of entries to write"); 269 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 270 "Current number of written entries"); 271 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 272 "Number of times we overran the buffer"); 273 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 274 "Number of items in the write buffer"); 275 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 276 sizeof(ktr_alq_file), "KTR logging file"); 277 278 static int 279 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 280 { 281 int error; 282 int enable; 283 284 enable = ktr_alq_enabled; 285 286 error = sysctl_handle_int(oidp, &enable, 0, req); 287 if (error || !req->newptr) 288 return (error); 289 290 if (enable) { 291 if (ktr_alq_enabled) 292 return (0); 293 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 294 req->td->td_ucred, ALQ_DEFAULT_CMODE, 295 sizeof(struct ktr_entry), ktr_alq_depth); 296 if (error == 0) { 297 ktr_alq_cnt = 0; 298 ktr_alq_failed = 0; 299 ktr_alq_enabled = 1; 300 } 301 } else { 302 if (ktr_alq_enabled == 0) 303 return (0); 304 ktr_alq_enabled = 0; 305 alq_close(ktr_alq); 306 ktr_alq = NULL; 307 } 308 309 return (error); 310 } 311 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 312 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, 313 sysctl_debug_ktr_alq_enable, "I", 314 "Enable KTR logging"); 315 #endif 316 317 void 318 ktr_tracepoint(uint64_t mask, const char *file, int line, const char *format, 319 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 320 u_long arg6) 321 { 322 struct ktr_entry *entry; 323 #ifdef KTR_ALQ 324 struct ale *ale = NULL; 325 #endif 326 int newindex, saveindex; 327 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 328 struct thread *td; 329 #endif 330 int cpu; 331 332 if (KERNEL_PANICKED() || kdb_active) 333 return; 334 if ((ktr_mask & mask) == 0 || ktr_buf == NULL) 335 return; 336 cpu = KTR_CPU; 337 if (!CPU_ISSET(cpu, &ktr_cpumask)) 338 return; 339 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 340 td = curthread; 341 if (td->td_pflags & TDP_INKTR) 342 return; 343 td->td_pflags |= TDP_INKTR; 344 #endif 345 #ifdef KTR_ALQ 346 if (ktr_alq_enabled) { 347 if (td->td_critnest == 0 && 348 (TD_IS_IDLETHREAD(td)) == 0 && 349 td != ald_thread) { 350 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 351 goto done; 352 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 353 ktr_alq_failed++; 354 goto done; 355 } 356 ktr_alq_cnt++; 357 entry = (struct ktr_entry *)ale->ae_data; 358 } else { 359 goto done; 360 } 361 } else 362 #endif 363 { 364 do { 365 saveindex = ktr_idx; 366 newindex = (saveindex + 1) % ktr_entries; 367 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 368 entry = &ktr_buf[saveindex]; 369 } 370 entry->ktr_timestamp = KTR_TIME; 371 entry->ktr_cpu = cpu; 372 entry->ktr_thread = curthread; 373 if (file != NULL) 374 while (strncmp(file, "../", 3) == 0) 375 file += 3; 376 entry->ktr_file = file; 377 entry->ktr_line = line; 378 #ifdef KTR_VERBOSE 379 if (ktr_verbose) { 380 #ifdef SMP 381 printf("cpu%d ", cpu); 382 #endif 383 if (ktr_verbose > 1) { 384 printf("%s.%d\t", entry->ktr_file, 385 entry->ktr_line); 386 } 387 printf(format, arg1, arg2, arg3, arg4, arg5, arg6); 388 printf("\n"); 389 } 390 #endif 391 entry->ktr_desc = format; 392 entry->ktr_parms[0] = arg1; 393 entry->ktr_parms[1] = arg2; 394 entry->ktr_parms[2] = arg3; 395 entry->ktr_parms[3] = arg4; 396 entry->ktr_parms[4] = arg5; 397 entry->ktr_parms[5] = arg6; 398 #ifdef KTR_ALQ 399 if (ktr_alq_enabled && ale) 400 alq_post(ktr_alq, ale); 401 done: 402 #endif 403 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 404 td->td_pflags &= ~TDP_INKTR; 405 #endif 406 } 407 408 #ifdef DDB 409 410 struct tstate { 411 int cur; 412 int first; 413 }; 414 static struct tstate tstate; 415 static int db_ktr_verbose; 416 static int db_mach_vtrace(void); 417 418 DB_SHOW_COMMAND_FLAGS(ktr, db_ktr_all, DB_CMD_MEMSAFE) 419 { 420 421 tstate.cur = (ktr_idx - 1) % ktr_entries; 422 tstate.first = -1; 423 db_ktr_verbose = 0; 424 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0; 425 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestamp please */ 426 if (strchr(modif, 'a') != NULL) { 427 db_disable_pager(); 428 while (cncheckc() == -1) 429 if (db_mach_vtrace() == 0) 430 break; 431 } else { 432 while (!db_pager_quit) 433 if (db_mach_vtrace() == 0) 434 break; 435 } 436 } 437 438 static int 439 db_mach_vtrace(void) 440 { 441 struct ktr_entry *kp; 442 443 if (tstate.cur == tstate.first || ktr_buf == NULL) { 444 db_printf("--- End of trace buffer ---\n"); 445 return (0); 446 } 447 kp = &ktr_buf[tstate.cur]; 448 449 /* Skip over unused entries. */ 450 if (kp->ktr_desc == NULL) { 451 db_printf("--- End of trace buffer ---\n"); 452 return (0); 453 } 454 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 455 #ifdef SMP 456 db_printf(":cpu%d", kp->ktr_cpu); 457 #endif 458 db_printf(")"); 459 if (db_ktr_verbose >= 1) { 460 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 461 } 462 if (db_ktr_verbose >= 2) { 463 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 464 } 465 db_printf(": "); 466 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 467 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 468 kp->ktr_parms[5]); 469 db_printf("\n"); 470 471 if (tstate.first == -1) 472 tstate.first = tstate.cur; 473 474 if (--tstate.cur < 0) 475 tstate.cur = ktr_entries - 1; 476 477 return (1); 478 } 479 480 #endif /* DDB */ 481