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, 0, "KTR options"); 106 107 SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, 108 &ktr_version, 0, "Version of the KTR interface"); 109 110 SYSCTL_UQUAD(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, 111 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel"); 112 113 static int 114 sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS) 115 { 116 char lktr_cpumask_str[CPUSETBUFSIZ]; 117 cpuset_t imask; 118 int error; 119 120 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask); 121 error = sysctl_handle_string(oidp, lktr_cpumask_str, 122 sizeof(lktr_cpumask_str), req); 123 if (error != 0 || req->newptr == NULL) 124 return (error); 125 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1) 126 return (EINVAL); 127 CPU_COPY(&imask, &ktr_cpumask); 128 129 return (error); 130 } 131 SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask, 132 CTLFLAG_RWTUN | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0, 133 sysctl_debug_ktr_cpumask, "S", 134 "Bitmask of CPUs on which KTR logging is enabled"); 135 136 static int 137 sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS) 138 { 139 int clear, error; 140 141 clear = 0; 142 error = sysctl_handle_int(oidp, &clear, 0, req); 143 if (error || !req->newptr) 144 return (error); 145 146 if (clear) { 147 bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries); 148 ktr_idx = 0; 149 } 150 151 return (error); 152 } 153 SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 154 sysctl_debug_ktr_clear, "I", "Clear KTR Buffer"); 155 156 /* 157 * This is a sysctl proc so that it is serialized as !MPSAFE along with 158 * the other ktr sysctl procs. 159 */ 160 static int 161 sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS) 162 { 163 uint64_t mask; 164 int error; 165 166 mask = ktr_mask; 167 error = sysctl_handle_64(oidp, &mask, 0, req); 168 if (error || !req->newptr) 169 return (error); 170 ktr_mask = mask; 171 return (error); 172 } 173 174 SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, CTLTYPE_U64 | CTLFLAG_RWTUN, 0, 0, 175 sysctl_debug_ktr_mask, "QU", 176 "Bitmask of KTR event classes for which logging is enabled"); 177 178 #if KTR_ENTRIES > KTR_BOOT_ENTRIES 179 /* 180 * A simplified version of sysctl_debug_ktr_entries. 181 * No need to care about SMP, scheduling, etc. 182 */ 183 static void 184 ktr_entries_initializer(void *dummy __unused) 185 { 186 uint64_t mask; 187 188 /* Temporarily disable ktr in case malloc() is being traced. */ 189 mask = ktr_mask; 190 ktr_mask = 0; 191 ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR, 192 M_WAITOK | M_ZERO); 193 memcpy(ktr_buf, ktr_buf_init + ktr_idx, 194 (KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf)); 195 if (ktr_idx != 0) { 196 memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init, 197 ktr_idx * sizeof(*ktr_buf)); 198 ktr_idx = KTR_BOOT_ENTRIES; 199 } 200 ktr_entries = KTR_ENTRIES; 201 ktr_mask = mask; 202 } 203 SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY, 204 ktr_entries_initializer, NULL); 205 #endif 206 207 static int 208 sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS) 209 { 210 uint64_t mask; 211 int entries, error; 212 struct ktr_entry *buf, *oldbuf; 213 214 entries = ktr_entries; 215 error = sysctl_handle_int(oidp, &entries, 0, req); 216 if (error || !req->newptr) 217 return (error); 218 if (entries > KTR_ENTRIES_MAX) 219 return (ERANGE); 220 /* Disable ktr temporarily. */ 221 mask = ktr_mask; 222 ktr_mask = 0; 223 /* Wait for threads to go idle. */ 224 if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) { 225 ktr_mask = mask; 226 return (error); 227 } 228 if (ktr_buf != ktr_buf_init) 229 oldbuf = ktr_buf; 230 else 231 oldbuf = NULL; 232 /* Allocate a new buffer. */ 233 buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO); 234 /* Install the new buffer and restart ktr. */ 235 ktr_buf = buf; 236 ktr_entries = entries; 237 ktr_idx = 0; 238 ktr_mask = mask; 239 if (oldbuf != NULL) 240 free(oldbuf, M_KTR); 241 242 return (error); 243 } 244 245 SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 246 sysctl_debug_ktr_entries, "I", "Number of entries in the KTR buffer"); 247 248 #ifdef KTR_VERBOSE 249 int ktr_verbose = KTR_VERBOSE; 250 TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 251 SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, ""); 252 #endif 253 254 #ifdef KTR_ALQ 255 struct alq *ktr_alq; 256 char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 257 int ktr_alq_cnt = 0; 258 int ktr_alq_depth = KTR_ENTRIES; 259 int ktr_alq_enabled = 0; 260 int ktr_alq_failed = 0; 261 int ktr_alq_max = 0; 262 263 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 264 "Maximum number of entries to write"); 265 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 266 "Current number of written entries"); 267 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 268 "Number of times we overran the buffer"); 269 SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 270 "Number of items in the write buffer"); 271 SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 272 sizeof(ktr_alq_file), "KTR logging file"); 273 274 static int 275 sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 276 { 277 int error; 278 int enable; 279 280 enable = ktr_alq_enabled; 281 282 error = sysctl_handle_int(oidp, &enable, 0, req); 283 if (error || !req->newptr) 284 return (error); 285 286 if (enable) { 287 if (ktr_alq_enabled) 288 return (0); 289 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 290 req->td->td_ucred, ALQ_DEFAULT_CMODE, 291 sizeof(struct ktr_entry), ktr_alq_depth); 292 if (error == 0) { 293 ktr_alq_cnt = 0; 294 ktr_alq_failed = 0; 295 ktr_alq_enabled = 1; 296 } 297 } else { 298 if (ktr_alq_enabled == 0) 299 return (0); 300 ktr_alq_enabled = 0; 301 alq_close(ktr_alq); 302 ktr_alq = NULL; 303 } 304 305 return (error); 306 } 307 SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 308 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable, 309 "I", "Enable KTR logging"); 310 #endif 311 312 void 313 ktr_tracepoint(uint64_t mask, const char *file, int line, const char *format, 314 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 315 u_long arg6) 316 { 317 struct ktr_entry *entry; 318 #ifdef KTR_ALQ 319 struct ale *ale = NULL; 320 #endif 321 int newindex, saveindex; 322 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 323 struct thread *td; 324 #endif 325 int cpu; 326 327 if (panicstr || kdb_active) 328 return; 329 if ((ktr_mask & mask) == 0 || ktr_buf == NULL) 330 return; 331 cpu = KTR_CPU; 332 if (!CPU_ISSET(cpu, &ktr_cpumask)) 333 return; 334 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 335 td = curthread; 336 if (td->td_pflags & TDP_INKTR) 337 return; 338 td->td_pflags |= TDP_INKTR; 339 #endif 340 #ifdef KTR_ALQ 341 if (ktr_alq_enabled) { 342 if (td->td_critnest == 0 && 343 (TD_IS_IDLETHREAD(td)) == 0 && 344 td != ald_thread) { 345 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 346 goto done; 347 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 348 ktr_alq_failed++; 349 goto done; 350 } 351 ktr_alq_cnt++; 352 entry = (struct ktr_entry *)ale->ae_data; 353 } else { 354 goto done; 355 } 356 } else 357 #endif 358 { 359 do { 360 saveindex = ktr_idx; 361 newindex = (saveindex + 1) % ktr_entries; 362 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 363 entry = &ktr_buf[saveindex]; 364 } 365 entry->ktr_timestamp = KTR_TIME; 366 entry->ktr_cpu = cpu; 367 entry->ktr_thread = curthread; 368 if (file != NULL) 369 while (strncmp(file, "../", 3) == 0) 370 file += 3; 371 entry->ktr_file = file; 372 entry->ktr_line = line; 373 #ifdef KTR_VERBOSE 374 if (ktr_verbose) { 375 #ifdef SMP 376 printf("cpu%d ", cpu); 377 #endif 378 if (ktr_verbose > 1) { 379 printf("%s.%d\t", entry->ktr_file, 380 entry->ktr_line); 381 } 382 printf(format, arg1, arg2, arg3, arg4, arg5, arg6); 383 printf("\n"); 384 } 385 #endif 386 entry->ktr_desc = format; 387 entry->ktr_parms[0] = arg1; 388 entry->ktr_parms[1] = arg2; 389 entry->ktr_parms[2] = arg3; 390 entry->ktr_parms[3] = arg4; 391 entry->ktr_parms[4] = arg5; 392 entry->ktr_parms[5] = arg6; 393 #ifdef KTR_ALQ 394 if (ktr_alq_enabled && ale) 395 alq_post(ktr_alq, ale); 396 done: 397 #endif 398 #if defined(KTR_VERBOSE) || defined(KTR_ALQ) 399 td->td_pflags &= ~TDP_INKTR; 400 #endif 401 } 402 403 #ifdef DDB 404 405 struct tstate { 406 int cur; 407 int first; 408 }; 409 static struct tstate tstate; 410 static int db_ktr_verbose; 411 static int db_mach_vtrace(void); 412 413 DB_SHOW_COMMAND(ktr, db_ktr_all) 414 { 415 416 tstate.cur = (ktr_idx - 1) % ktr_entries; 417 tstate.first = -1; 418 db_ktr_verbose = 0; 419 db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0; 420 db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestamp please */ 421 if (strchr(modif, 'a') != NULL) { 422 db_disable_pager(); 423 while (cncheckc() == -1) 424 if (db_mach_vtrace() == 0) 425 break; 426 } else { 427 while (!db_pager_quit) 428 if (db_mach_vtrace() == 0) 429 break; 430 } 431 } 432 433 static int 434 db_mach_vtrace(void) 435 { 436 struct ktr_entry *kp; 437 438 if (tstate.cur == tstate.first || ktr_buf == NULL) { 439 db_printf("--- End of trace buffer ---\n"); 440 return (0); 441 } 442 kp = &ktr_buf[tstate.cur]; 443 444 /* Skip over unused entries. */ 445 if (kp->ktr_desc == NULL) { 446 db_printf("--- End of trace buffer ---\n"); 447 return (0); 448 } 449 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 450 #ifdef SMP 451 db_printf(":cpu%d", kp->ktr_cpu); 452 #endif 453 db_printf(")"); 454 if (db_ktr_verbose >= 1) { 455 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 456 } 457 if (db_ktr_verbose >= 2) { 458 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 459 } 460 db_printf(": "); 461 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 462 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 463 kp->ktr_parms[5]); 464 db_printf("\n"); 465 466 if (tstate.first == -1) 467 tstate.first = tstate.cur; 468 469 if (--tstate.cur < 0) 470 tstate.cur = ktr_entries - 1; 471 472 return (1); 473 } 474 475 #endif /* DDB */ 476