kern_ktr.c revision 222813
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 * 3. Neither the name of the author nor the names of any co-contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30/* 31 * This module holds the global variables used by KTR and the ktr_tracepoint() 32 * function that does the actual tracing. 33 */ 34 35#include <sys/cdefs.h> 36__FBSDID("$FreeBSD: head/sys/kern/kern_ktr.c 222813 2011-06-07 08:46:13Z attilio $"); 37 38#include "opt_ddb.h" 39#include "opt_ktr.h" 40#include "opt_alq.h" 41 42#include <sys/param.h> 43#include <sys/queue.h> 44#include <sys/alq.h> 45#include <sys/cons.h> 46#include <sys/cpuset.h> 47#include <sys/kernel.h> 48#include <sys/ktr.h> 49#include <sys/libkern.h> 50#include <sys/proc.h> 51#include <sys/sysctl.h> 52#include <sys/systm.h> 53#include <sys/time.h> 54 55#include <machine/cpu.h> 56#ifdef __sparc64__ 57#include <machine/ktr.h> 58#endif 59 60#ifdef DDB 61#include <ddb/ddb.h> 62#include <ddb/db_output.h> 63#endif 64 65#ifndef KTR_ENTRIES 66#define KTR_ENTRIES 1024 67#endif 68 69#ifndef KTR_MASK 70#define KTR_MASK (0) 71#endif 72 73#ifndef KTR_TIME 74#define KTR_TIME get_cyclecount() 75#endif 76 77#ifndef KTR_CPU 78#define KTR_CPU PCPU_GET(cpuid) 79#endif 80 81FEATURE(ktr, "Kernel support for KTR kernel tracing facility"); 82 83SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options"); 84 85int ktr_mask = KTR_MASK; 86TUNABLE_INT("debug.ktr.mask", &ktr_mask); 87SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW, 88 &ktr_mask, 0, "Bitmask of KTR event classes for which logging is enabled"); 89 90int ktr_compile = KTR_COMPILE; 91SYSCTL_INT(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD, 92 &ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel"); 93 94int ktr_entries = KTR_ENTRIES; 95SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, 96 &ktr_entries, 0, "Number of entries in the KTR buffer"); 97 98int ktr_version = KTR_VERSION; 99SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD, 100 &ktr_version, 0, "Version of the KTR interface"); 101 102cpuset_t ktr_cpumask; 103static char ktr_cpumask_str[CPUSETBUFSIZ]; 104TUNABLE_STR("debug.ktr.cpumask", ktr_cpumask_str, sizeof(ktr_cpumask_str)); 105 106static void 107ktr_cpumask_initializer(void *dummy __unused) 108{ 109 110 CPU_FILL(&ktr_cpumask); 111#ifdef KTR_CPUMASK 112 if (cpusetobj_strscan(&ktr_cpumask, KTR_CPUMASK) == -1) 113 CPU_FILL(&ktr_cpumask); 114#endif 115 116 /* 117 * TUNABLE_STR() runs with SI_ORDER_MIDDLE priority, thus it must be 118 * already set, if necessary. 119 */ 120 if (ktr_cpumask_str[0] != '\0' && 121 cpusetobj_strscan(&ktr_cpumask, ktr_cpumask_str) == -1) 122 CPU_FILL(&ktr_cpumask); 123} 124SYSINIT(ktr_cpumask_initializer, SI_SUB_TUNABLES, SI_ORDER_ANY, 125 ktr_cpumask_initializer, NULL); 126 127static int 128sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS) 129{ 130 char lktr_cpumask_str[CPUSETBUFSIZ]; 131 cpuset_t imask; 132 int error; 133 134 cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask); 135 error = sysctl_handle_string(oidp, lktr_cpumask_str, 136 sizeof(lktr_cpumask_str), req); 137 if (error != 0 || req->newptr == NULL) 138 return (error); 139 if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1) 140 return (EINVAL); 141 CPU_COPY(&imask, &ktr_cpumask); 142 143 return (error); 144} 145SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask, 146 CTLFLAG_RW | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0, 147 sysctl_debug_ktr_cpumask, "S", 148 "Bitmask of CPUs on which KTR logging is enabled"); 149 150volatile int ktr_idx = 0; 151struct ktr_entry ktr_buf[KTR_ENTRIES]; 152 153static int 154sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS) 155{ 156 int clear, error; 157 158 clear = 0; 159 error = sysctl_handle_int(oidp, &clear, 0, req); 160 if (error || !req->newptr) 161 return (error); 162 163 if (clear) { 164 bzero(ktr_buf, sizeof(ktr_buf)); 165 ktr_idx = 0; 166 } 167 168 return (error); 169} 170SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0, 171 sysctl_debug_ktr_clear, "I", "Clear KTR Buffer"); 172 173#ifdef KTR_VERBOSE 174int ktr_verbose = KTR_VERBOSE; 175TUNABLE_INT("debug.ktr.verbose", &ktr_verbose); 176SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, ""); 177#endif 178 179#ifdef KTR_ALQ 180struct alq *ktr_alq; 181char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out"; 182int ktr_alq_cnt = 0; 183int ktr_alq_depth = KTR_ENTRIES; 184int ktr_alq_enabled = 0; 185int ktr_alq_failed = 0; 186int ktr_alq_max = 0; 187 188SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0, 189 "Maximum number of entries to write"); 190SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0, 191 "Current number of written entries"); 192SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0, 193 "Number of times we overran the buffer"); 194SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0, 195 "Number of items in the write buffer"); 196SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file, 197 sizeof(ktr_alq_file), "KTR logging file"); 198 199static int 200sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS) 201{ 202 int error; 203 int enable; 204 205 enable = ktr_alq_enabled; 206 207 error = sysctl_handle_int(oidp, &enable, 0, req); 208 if (error || !req->newptr) 209 return (error); 210 211 if (enable) { 212 if (ktr_alq_enabled) 213 return (0); 214 error = alq_open(&ktr_alq, (const char *)ktr_alq_file, 215 req->td->td_ucred, ALQ_DEFAULT_CMODE, 216 sizeof(struct ktr_entry), ktr_alq_depth); 217 if (error == 0) { 218 ktr_alq_cnt = 0; 219 ktr_alq_failed = 0; 220 ktr_alq_enabled = 1; 221 } 222 } else { 223 if (ktr_alq_enabled == 0) 224 return (0); 225 ktr_alq_enabled = 0; 226 alq_close(ktr_alq); 227 ktr_alq = NULL; 228 } 229 230 return (error); 231} 232SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable, 233 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable, 234 "I", "Enable KTR logging"); 235#endif 236 237void 238ktr_tracepoint(u_int mask, const char *file, int line, const char *format, 239 u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5, 240 u_long arg6) 241{ 242 struct ktr_entry *entry; 243#ifdef KTR_ALQ 244 struct ale *ale = NULL; 245#endif 246 int newindex, saveindex; 247#if defined(KTR_VERBOSE) || defined(KTR_ALQ) 248 struct thread *td; 249#endif 250 int cpu; 251 252 if (panicstr) 253 return; 254 if ((ktr_mask & mask) == 0) 255 return; 256 cpu = KTR_CPU; 257 if (!CPU_ISSET(cpu, &ktr_cpumask)) 258 return; 259#if defined(KTR_VERBOSE) || defined(KTR_ALQ) 260 td = curthread; 261 if (td->td_pflags & TDP_INKTR) 262 return; 263 td->td_pflags |= TDP_INKTR; 264#endif 265#ifdef KTR_ALQ 266 if (ktr_alq_enabled) { 267 if (td->td_critnest == 0 && 268 (td->td_flags & TDF_IDLETD) == 0 && 269 td != ald_thread) { 270 if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max) 271 goto done; 272 if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) { 273 ktr_alq_failed++; 274 goto done; 275 } 276 ktr_alq_cnt++; 277 entry = (struct ktr_entry *)ale->ae_data; 278 } else { 279 goto done; 280 } 281 } else 282#endif 283 { 284 do { 285 saveindex = ktr_idx; 286 newindex = (saveindex + 1) & (KTR_ENTRIES - 1); 287 } while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0); 288 entry = &ktr_buf[saveindex]; 289 } 290 entry->ktr_timestamp = KTR_TIME; 291 entry->ktr_cpu = cpu; 292 entry->ktr_thread = curthread; 293 if (file != NULL) 294 while (strncmp(file, "../", 3) == 0) 295 file += 3; 296 entry->ktr_file = file; 297 entry->ktr_line = line; 298#ifdef KTR_VERBOSE 299 if (ktr_verbose) { 300#ifdef SMP 301 printf("cpu%d ", cpu); 302#endif 303 if (ktr_verbose > 1) { 304 printf("%s.%d\t", entry->ktr_file, 305 entry->ktr_line); 306 } 307 printf(format, arg1, arg2, arg3, arg4, arg5, arg6); 308 printf("\n"); 309 } 310#endif 311 entry->ktr_desc = format; 312 entry->ktr_parms[0] = arg1; 313 entry->ktr_parms[1] = arg2; 314 entry->ktr_parms[2] = arg3; 315 entry->ktr_parms[3] = arg4; 316 entry->ktr_parms[4] = arg5; 317 entry->ktr_parms[5] = arg6; 318#ifdef KTR_ALQ 319 if (ktr_alq_enabled && ale) 320 alq_post(ktr_alq, ale); 321done: 322#endif 323#if defined(KTR_VERBOSE) || defined(KTR_ALQ) 324 td->td_pflags &= ~TDP_INKTR; 325#endif 326} 327 328#ifdef DDB 329 330struct tstate { 331 int cur; 332 int first; 333}; 334static struct tstate tstate; 335static int db_ktr_verbose; 336static int db_mach_vtrace(void); 337 338DB_SHOW_COMMAND(ktr, db_ktr_all) 339{ 340 341 tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1); 342 tstate.first = -1; 343 db_ktr_verbose = 0; 344 db_ktr_verbose |= (index(modif, 'v') != NULL) ? 2 : 0; 345 db_ktr_verbose |= (index(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */ 346 if (index(modif, 'a') != NULL) { 347 db_disable_pager(); 348 while (cncheckc() != -1) 349 if (db_mach_vtrace() == 0) 350 break; 351 } else { 352 while (!db_pager_quit) 353 if (db_mach_vtrace() == 0) 354 break; 355 } 356} 357 358static int 359db_mach_vtrace(void) 360{ 361 struct ktr_entry *kp; 362 363 if (tstate.cur == tstate.first) { 364 db_printf("--- End of trace buffer ---\n"); 365 return (0); 366 } 367 kp = &ktr_buf[tstate.cur]; 368 369 /* Skip over unused entries. */ 370 if (kp->ktr_desc == NULL) { 371 db_printf("--- End of trace buffer ---\n"); 372 return (0); 373 } 374 db_printf("%d (%p", tstate.cur, kp->ktr_thread); 375#ifdef SMP 376 db_printf(":cpu%d", kp->ktr_cpu); 377#endif 378 db_printf(")"); 379 if (db_ktr_verbose >= 1) { 380 db_printf(" %10.10lld", (long long)kp->ktr_timestamp); 381 } 382 if (db_ktr_verbose >= 2) { 383 db_printf(" %s.%d", kp->ktr_file, kp->ktr_line); 384 } 385 db_printf(": "); 386 db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1], 387 kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4], 388 kp->ktr_parms[5]); 389 db_printf("\n"); 390 391 if (tstate.first == -1) 392 tstate.first = tstate.cur; 393 394 if (--tstate.cur < 0) 395 tstate.cur = KTR_ENTRIES - 1; 396 397 return (1); 398} 399 400#endif /* DDB */ 401