1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include <sys/errno.h> 30 #include <sys/stat.h> 31 #include <sys/modctl.h> 32 #include <sys/conf.h> 33 #include <sys/systm.h> 34 #include <sys/ddi.h> 35 #include <sys/sunddi.h> 36 #include <sys/cpuvar.h> 37 #include <sys/kmem.h> 38 #include <sys/strsubr.h> 39 #include <sys/dtrace.h> 40 #include <sys/cyclic.h> 41 #include <sys/atomic.h> 42 43 static dev_info_t *profile_devi; 44 static dtrace_provider_id_t profile_id; 45 46 /* 47 * Regardless of platform, there are five artificial frames in the case of the 48 * profile provider: 49 * 50 * profile_fire 51 * cyclic_expire 52 * cyclic_fire 53 * [ cbe ] 54 * [ locore ] 55 * 56 * On amd64, there are two frames associated with locore: one in locore, and 57 * another in common interrupt dispatch code. (i386 has not been modified to 58 * use this common layer.) Further, on i386, the interrupted instruction 59 * appears as its own stack frame. All of this means that we need to add one 60 * frame for amd64, and then take one away for both amd64 and i386. 61 * 62 * On SPARC, the picture is further complicated because the compiler 63 * optimizes away tail-calls -- so the following frames are optimized away: 64 * 65 * profile_fire 66 * cyclic_expire 67 * 68 * This gives three frames. However, on DEBUG kernels, the cyclic_expire 69 * frame cannot be tail-call eliminated, yielding four frames in this case. 70 * 71 * All of the above constraints lead to the mess below. Yes, the profile 72 * provider should ideally figure this out on-the-fly by hiting one of its own 73 * probes and then walking its own stack trace. This is complicated, however, 74 * and the static definition doesn't seem to be overly brittle. Still, we 75 * allow for a manual override in case we get it completely wrong. 76 */ 77 #ifdef __amd64 78 #define PROF_ARTIFICIAL_FRAMES 7 79 #else 80 #ifdef __i386 81 #define PROF_ARTIFICIAL_FRAMES 6 82 #else 83 #ifdef __sparc 84 #ifdef DEBUG 85 #define PROF_ARTIFICIAL_FRAMES 4 86 #else 87 #define PROF_ARTIFICIAL_FRAMES 3 88 #endif 89 #endif 90 #endif 91 #endif 92 93 #define PROF_NAMELEN 15 94 95 #define PROF_PROFILE 0 96 #define PROF_TICK 1 97 #define PROF_PREFIX_PROFILE "profile-" 98 #define PROF_PREFIX_TICK "tick-" 99 100 typedef struct profile_probe { 101 char prof_name[PROF_NAMELEN]; 102 dtrace_id_t prof_id; 103 int prof_kind; 104 hrtime_t prof_interval; 105 cyclic_id_t prof_cyclic; 106 } profile_probe_t; 107 108 typedef struct profile_probe_percpu { 109 hrtime_t profc_expected; 110 hrtime_t profc_interval; 111 profile_probe_t *profc_probe; 112 } profile_probe_percpu_t; 113 114 hrtime_t profile_interval_min = NANOSEC / 5000; /* 5000 hz */ 115 int profile_aframes = 0; /* override */ 116 117 static int profile_rates[] = { 118 97, 199, 499, 997, 1999, 119 4001, 4999, 0, 0, 0, 120 0, 0, 0, 0, 0, 121 0, 0, 0, 0, 0 122 }; 123 124 static int profile_ticks[] = { 125 1, 10, 100, 500, 1000, 126 5000, 0, 0, 0, 0, 127 0, 0, 0, 0, 0 128 }; 129 130 /* 131 * profile_max defines the upper bound on the number of profile probes that 132 * can exist (this is to prevent malicious or clumsy users from exhausing 133 * system resources by creating a slew of profile probes). At mod load time, 134 * this gets its value from PROFILE_MAX_DEFAULT or profile-max-probes if it's 135 * present in the profile.conf file. 136 */ 137 #define PROFILE_MAX_DEFAULT 1000 /* default max. number of probes */ 138 static uint32_t profile_max; /* maximum number of profile probes */ 139 static uint32_t profile_total; /* current number of profile probes */ 140 141 static void 142 profile_fire(void *arg) 143 { 144 profile_probe_percpu_t *pcpu = arg; 145 profile_probe_t *prof = pcpu->profc_probe; 146 hrtime_t late; 147 148 late = dtrace_gethrtime() - pcpu->profc_expected; 149 pcpu->profc_expected += pcpu->profc_interval; 150 151 dtrace_probe(prof->prof_id, CPU->cpu_profile_pc, 152 CPU->cpu_profile_upc, late, 0, 0); 153 } 154 155 static void 156 profile_tick(void *arg) 157 { 158 profile_probe_t *prof = arg; 159 160 dtrace_probe(prof->prof_id, CPU->cpu_profile_pc, 161 CPU->cpu_profile_upc, 0, 0, 0); 162 } 163 164 static void 165 profile_create(hrtime_t interval, const char *name, int kind) 166 { 167 profile_probe_t *prof; 168 169 if (interval < profile_interval_min) 170 return; 171 172 if (dtrace_probe_lookup(profile_id, NULL, NULL, name) != 0) 173 return; 174 175 atomic_add_32(&profile_total, 1); 176 if (profile_total > profile_max) { 177 atomic_add_32(&profile_total, -1); 178 return; 179 } 180 181 prof = kmem_zalloc(sizeof (profile_probe_t), KM_SLEEP); 182 (void) strcpy(prof->prof_name, name); 183 prof->prof_interval = interval; 184 prof->prof_cyclic = CYCLIC_NONE; 185 prof->prof_kind = kind; 186 prof->prof_id = dtrace_probe_create(profile_id, 187 NULL, NULL, name, 188 profile_aframes ? profile_aframes : PROF_ARTIFICIAL_FRAMES, prof); 189 } 190 191 /*ARGSUSED*/ 192 static void 193 profile_provide(void *arg, const dtrace_probedesc_t *desc) 194 { 195 int i, j, rate, kind; 196 hrtime_t val = 0, mult = 1, len; 197 const char *name, *suffix = NULL; 198 199 const struct { 200 char *prefix; 201 int kind; 202 } types[] = { 203 { PROF_PREFIX_PROFILE, PROF_PROFILE }, 204 { PROF_PREFIX_TICK, PROF_TICK }, 205 { NULL, NULL } 206 }; 207 208 const struct { 209 char *name; 210 hrtime_t mult; 211 } suffixes[] = { 212 { "ns", NANOSEC / NANOSEC }, 213 { "nsec", NANOSEC / NANOSEC }, 214 { "us", NANOSEC / MICROSEC }, 215 { "usec", NANOSEC / MICROSEC }, 216 { "ms", NANOSEC / MILLISEC }, 217 { "msec", NANOSEC / MILLISEC }, 218 { "s", NANOSEC / SEC }, 219 { "sec", NANOSEC / SEC }, 220 { "m", NANOSEC * (hrtime_t)60 }, 221 { "min", NANOSEC * (hrtime_t)60 }, 222 { "h", NANOSEC * (hrtime_t)(60 * 60) }, 223 { "hour", NANOSEC * (hrtime_t)(60 * 60) }, 224 { "d", NANOSEC * (hrtime_t)(24 * 60 * 60) }, 225 { "day", NANOSEC * (hrtime_t)(24 * 60 * 60) }, 226 { "hz", 0 }, 227 { NULL } 228 }; 229 230 if (desc == NULL) { 231 char n[PROF_NAMELEN]; 232 233 /* 234 * If no description was provided, provide all of our probes. 235 */ 236 for (i = 0; i < sizeof (profile_rates) / sizeof (int); i++) { 237 if ((rate = profile_rates[i]) == 0) 238 continue; 239 240 (void) snprintf(n, PROF_NAMELEN, "%s%d", 241 PROF_PREFIX_PROFILE, rate); 242 profile_create(NANOSEC / rate, n, PROF_PROFILE); 243 } 244 245 for (i = 0; i < sizeof (profile_ticks) / sizeof (int); i++) { 246 if ((rate = profile_ticks[i]) == 0) 247 continue; 248 249 (void) snprintf(n, PROF_NAMELEN, "%s%d", 250 PROF_PREFIX_TICK, rate); 251 profile_create(NANOSEC / rate, n, PROF_TICK); 252 } 253 254 return; 255 } 256 257 name = desc->dtpd_name; 258 259 for (i = 0; types[i].prefix != NULL; i++) { 260 len = strlen(types[i].prefix); 261 262 if (strncmp(name, types[i].prefix, len) != 0) 263 continue; 264 break; 265 } 266 267 if (types[i].prefix == NULL) 268 return; 269 270 kind = types[i].kind; 271 j = strlen(name) - len; 272 273 /* 274 * We need to start before any time suffix. 275 */ 276 for (j = strlen(name); j >= len; j--) { 277 if (name[j] >= '0' && name[j] <= '9') 278 break; 279 suffix = &name[j]; 280 } 281 282 ASSERT(suffix != NULL); 283 284 /* 285 * Now determine the numerical value present in the probe name. 286 */ 287 for (; j >= len; j--) { 288 if (name[j] < '0' || name[j] > '9') 289 return; 290 291 val += (name[j] - '0') * mult; 292 mult *= (hrtime_t)10; 293 } 294 295 if (val == 0) 296 return; 297 298 /* 299 * Look-up the suffix to determine the multiplier. 300 */ 301 for (i = 0, mult = 0; suffixes[i].name != NULL; i++) { 302 if (strcasecmp(suffixes[i].name, suffix) == 0) { 303 mult = suffixes[i].mult; 304 break; 305 } 306 } 307 308 if (suffixes[i].name == NULL && *suffix != '\0') 309 return; 310 311 if (mult == 0) { 312 /* 313 * The default is frequency-per-second. 314 */ 315 val = NANOSEC / val; 316 } else { 317 val *= mult; 318 } 319 320 profile_create(val, name, kind); 321 } 322 323 /*ARGSUSED*/ 324 static void 325 profile_destroy(void *arg, dtrace_id_t id, void *parg) 326 { 327 profile_probe_t *prof = parg; 328 329 ASSERT(prof->prof_cyclic == CYCLIC_NONE); 330 kmem_free(prof, sizeof (profile_probe_t)); 331 332 ASSERT(profile_total >= 1); 333 atomic_add_32(&profile_total, -1); 334 } 335 336 /*ARGSUSED*/ 337 static void 338 profile_online(void *arg, cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when) 339 { 340 profile_probe_t *prof = arg; 341 profile_probe_percpu_t *pcpu; 342 343 pcpu = kmem_zalloc(sizeof (profile_probe_percpu_t), KM_SLEEP); 344 pcpu->profc_probe = prof; 345 346 hdlr->cyh_func = profile_fire; 347 hdlr->cyh_arg = pcpu; 348 hdlr->cyh_level = CY_HIGH_LEVEL; 349 350 when->cyt_interval = prof->prof_interval; 351 when->cyt_when = dtrace_gethrtime() + when->cyt_interval; 352 353 pcpu->profc_expected = when->cyt_when; 354 pcpu->profc_interval = when->cyt_interval; 355 } 356 357 /*ARGSUSED*/ 358 static void 359 profile_offline(void *arg, cpu_t *cpu, void *oarg) 360 { 361 profile_probe_percpu_t *pcpu = oarg; 362 363 ASSERT(pcpu->profc_probe == arg); 364 kmem_free(pcpu, sizeof (profile_probe_percpu_t)); 365 } 366 367 /*ARGSUSED*/ 368 static void 369 profile_enable(void *arg, dtrace_id_t id, void *parg) 370 { 371 profile_probe_t *prof = parg; 372 cyc_omni_handler_t omni; 373 cyc_handler_t hdlr; 374 cyc_time_t when; 375 376 ASSERT(prof->prof_interval != 0); 377 ASSERT(MUTEX_HELD(&cpu_lock)); 378 379 if (prof->prof_kind == PROF_TICK) { 380 hdlr.cyh_func = profile_tick; 381 hdlr.cyh_arg = prof; 382 hdlr.cyh_level = CY_HIGH_LEVEL; 383 384 when.cyt_interval = prof->prof_interval; 385 when.cyt_when = dtrace_gethrtime() + when.cyt_interval; 386 } else { 387 ASSERT(prof->prof_kind == PROF_PROFILE); 388 omni.cyo_online = profile_online; 389 omni.cyo_offline = profile_offline; 390 omni.cyo_arg = prof; 391 } 392 393 if (prof->prof_kind == PROF_TICK) { 394 prof->prof_cyclic = cyclic_add(&hdlr, &when); 395 } else { 396 prof->prof_cyclic = cyclic_add_omni(&omni); 397 } 398 } 399 400 /*ARGSUSED*/ 401 static void 402 profile_disable(void *arg, dtrace_id_t id, void *parg) 403 { 404 profile_probe_t *prof = parg; 405 406 ASSERT(prof->prof_cyclic != CYCLIC_NONE); 407 ASSERT(MUTEX_HELD(&cpu_lock)); 408 409 cyclic_remove(prof->prof_cyclic); 410 prof->prof_cyclic = CYCLIC_NONE; 411 } 412 413 /*ARGSUSED*/ 414 static int 415 profile_usermode(void *arg, dtrace_id_t id, void *parg) 416 { 417 return (CPU->cpu_profile_pc == 0); 418 } 419 420 static dtrace_pattr_t profile_attr = { 421 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 422 { DTRACE_STABILITY_UNSTABLE, DTRACE_STABILITY_UNSTABLE, DTRACE_CLASS_UNKNOWN }, 423 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, 424 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 425 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 426 }; 427 428 static dtrace_pops_t profile_pops = { 429 profile_provide, 430 NULL, 431 profile_enable, 432 profile_disable, 433 NULL, 434 NULL, 435 NULL, 436 NULL, 437 profile_usermode, 438 profile_destroy 439 }; 440 441 static int 442 profile_attach(dev_info_t *devi, ddi_attach_cmd_t cmd) 443 { 444 switch (cmd) { 445 case DDI_ATTACH: 446 break; 447 case DDI_RESUME: 448 return (DDI_SUCCESS); 449 default: 450 return (DDI_FAILURE); 451 } 452 453 if (ddi_create_minor_node(devi, "profile", S_IFCHR, 0, 454 DDI_PSEUDO, NULL) == DDI_FAILURE || 455 dtrace_register("profile", &profile_attr, 456 DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER, 0, 457 &profile_pops, NULL, &profile_id) != 0) { 458 ddi_remove_minor_node(devi, NULL); 459 return (DDI_FAILURE); 460 } 461 462 profile_max = ddi_getprop(DDI_DEV_T_ANY, devi, DDI_PROP_DONTPASS, 463 "profile-max-probes", PROFILE_MAX_DEFAULT); 464 465 ddi_report_dev(devi); 466 profile_devi = devi; 467 return (DDI_SUCCESS); 468 } 469 470 static int 471 profile_detach(dev_info_t *devi, ddi_detach_cmd_t cmd) 472 { 473 switch (cmd) { 474 case DDI_DETACH: 475 break; 476 case DDI_SUSPEND: 477 return (DDI_SUCCESS); 478 default: 479 return (DDI_FAILURE); 480 } 481 482 if (dtrace_unregister(profile_id) != 0) 483 return (DDI_FAILURE); 484 485 ddi_remove_minor_node(devi, NULL); 486 return (DDI_SUCCESS); 487 } 488 489 /*ARGSUSED*/ 490 static int 491 profile_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result) 492 { 493 int error; 494 495 switch (infocmd) { 496 case DDI_INFO_DEVT2DEVINFO: 497 *result = (void *)profile_devi; 498 error = DDI_SUCCESS; 499 break; 500 case DDI_INFO_DEVT2INSTANCE: 501 *result = (void *)0; 502 error = DDI_SUCCESS; 503 break; 504 default: 505 error = DDI_FAILURE; 506 } 507 return (error); 508 } 509 510 /*ARGSUSED*/ 511 static int 512 profile_open(dev_t *devp, int flag, int otyp, cred_t *cred_p) 513 { 514 return (0); 515 } 516 517 static struct cb_ops profile_cb_ops = { 518 profile_open, /* open */ 519 nodev, /* close */ 520 nulldev, /* strategy */ 521 nulldev, /* print */ 522 nodev, /* dump */ 523 nodev, /* read */ 524 nodev, /* write */ 525 nodev, /* ioctl */ 526 nodev, /* devmap */ 527 nodev, /* mmap */ 528 nodev, /* segmap */ 529 nochpoll, /* poll */ 530 ddi_prop_op, /* cb_prop_op */ 531 0, /* streamtab */ 532 D_NEW | D_MP /* Driver compatibility flag */ 533 }; 534 535 static struct dev_ops profile_ops = { 536 DEVO_REV, /* devo_rev, */ 537 0, /* refcnt */ 538 profile_info, /* get_dev_info */ 539 nulldev, /* identify */ 540 nulldev, /* probe */ 541 profile_attach, /* attach */ 542 profile_detach, /* detach */ 543 nodev, /* reset */ 544 &profile_cb_ops, /* driver operations */ 545 NULL, /* bus operations */ 546 nodev /* dev power */ 547 }; 548 549 /* 550 * Module linkage information for the kernel. 551 */ 552 static struct modldrv modldrv = { 553 &mod_driverops, /* module type (this is a pseudo driver) */ 554 "Profile Interrupt Tracing", /* name of module */ 555 &profile_ops, /* driver ops */ 556 }; 557 558 static struct modlinkage modlinkage = { 559 MODREV_1, 560 (void *)&modldrv, 561 NULL 562 }; 563 564 int 565 _init(void) 566 { 567 return (mod_install(&modlinkage)); 568 } 569 570 int 571 _info(struct modinfo *modinfop) 572 { 573 return (mod_info(&modlinkage, modinfop)); 574 } 575 576 int 577 _fini(void) 578 { 579 return (mod_remove(&modlinkage)); 580 } 581