bsd/dev/dtrace/profile_prvd.c

   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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /* #pragma ident        "@(#)profile.c  1.7     07/01/10 SMI" */
  27
  28 #ifdef KERNEL
  29 #ifndef _KERNEL
  30 #define _KERNEL /* Solaris vs. Darwin */
  31 #endif
  32 #endif
  33
  34 #include <kern/cpu_data.h>
  35 #include <kern/thread.h>
  36 #include <kern/assert.h>
  37 #include <mach/thread_status.h>
  38
  39 #include <sys/param.h>
  40 #include <sys/systm.h>
  41 #include <sys/errno.h>
  42 #include <sys/stat.h>
  43 #include <sys/ioctl.h>
  44 #include <sys/conf.h>
  45 #include <sys/fcntl.h>
  46 #include <miscfs/devfs/devfs.h>
  47
  48 #include <sys/dtrace.h>
  49 #include <sys/dtrace_impl.h>
  50
  51 #include <sys/dtrace_glue.h>
  52
  53 #include <machine/pal_routines.h>
  54
  55 #if defined(__x86_64__)
  56 extern x86_saved_state_t *find_kern_regs(thread_t);
  57 #else
  58 #error Unknown architecture
  59 #endif
  60
  61 #undef ASSERT
  62 #define ASSERT(x) do {} while(0)
  63
  64 extern void profile_init(void);
  65
  66 static dev_info_t *profile_devi;
  67 static dtrace_provider_id_t profile_id;
  68
  69 /*
  70  * Regardless of platform, the stack frames look like this in the case of the
  71  * profile provider:
  72  *
  73  *      profile_fire
  74  *      cyclic_expire
  75  *      cyclic_fire
  76  *      [ cbe ]
  77  *      [ interrupt code ]
  78  *
  79  * On x86, there are five frames from the generic interrupt code; further, the
  80  * interrupted instruction appears as its own stack frame, giving us a total of
  81  * 10.
  82  *
  83  * On SPARC, the picture is further complicated because the compiler
  84  * optimizes away tail-calls -- so the following frames are optimized away:
  85  *
  86  *      profile_fire
  87  *      cyclic_expire
  88  *
  89  * This gives three frames.  However, on DEBUG kernels, the cyclic_expire
  90  * frame cannot be tail-call eliminated, yielding four frames in this case.
  91  *
  92  * All of the above constraints lead to the mess below.  Yes, the profile
  93  * provider should ideally figure this out on-the-fly by hitting one of its own
  94  * probes and then walking its own stack trace.  This is complicated, however,
  95  * and the static definition doesn't seem to be overly brittle.  Still, we
  96  * allow for a manual override in case we get it completely wrong.
  97  */
  98
  99 #if defined(__x86_64__)
 100 #define PROF_ARTIFICIAL_FRAMES  9
 101 #else
 102 #error Unknown architecture
 103 #endif
 104
 105 #define PROF_NAMELEN            15
 106
 107 #define PROF_PROFILE            0
 108 #define PROF_TICK               1
 109 #define PROF_PREFIX_PROFILE     "profile-"
 110 #define PROF_PREFIX_TICK        "tick-"
 111
 112 typedef struct profile_probe {
 113         char            prof_name[PROF_NAMELEN];
 114         dtrace_id_t     prof_id;
 115         int             prof_kind;
 116         hrtime_t        prof_interval;
 117         cyclic_id_t     prof_cyclic;
 118 } profile_probe_t;
 119
 120 typedef struct profile_probe_percpu {
 121         hrtime_t        profc_expected;
 122         hrtime_t        profc_interval;
 123         profile_probe_t *profc_probe;
 124 } profile_probe_percpu_t;
 125
 126 hrtime_t        profile_interval_min = NANOSEC / 5000;          /* 5000 hz */
 127 int             profile_aframes = 0;                            /* override */
 128
 129 static int profile_rates[] = {
 130     97, 199, 499, 997, 1999,
 131     4001, 4999, 0, 0, 0,
 132     0, 0, 0, 0, 0,
 133     0, 0, 0, 0, 0
 134 };
 135
 136 static int profile_ticks[] = {
 137     1, 10, 100, 500, 1000,
 138     5000, 0, 0, 0, 0,
 139     0, 0, 0, 0, 0
 140 };
 141
 142 /*
 143  * profile_max defines the upper bound on the number of profile probes that
 144  * can exist (this is to prevent malicious or clumsy users from exhausing
 145  * system resources by creating a slew of profile probes). At mod load time,
 146  * this gets its value from PROFILE_MAX_DEFAULT or profile-max-probes if it's
 147  * present in the profile.conf file.
 148  */
 149 #define PROFILE_MAX_DEFAULT     1000    /* default max. number of probes */
 150 static uint32_t profile_max;            /* maximum number of profile probes */
 151 static uint32_t profile_total;  /* current number of profile probes */
 152
 153 static void
 154 profile_fire(void *arg)
 155 {
 156         profile_probe_percpu_t *pcpu = arg;
 157         profile_probe_t *prof = pcpu->profc_probe;
 158         hrtime_t late;
 159
 160         late = dtrace_gethrtime() - pcpu->profc_expected;
 161         pcpu->profc_expected += pcpu->profc_interval;
 162
 163 #if defined(__x86_64__)
 164         x86_saved_state_t *kern_regs = find_kern_regs(current_thread());
 165
 166         if (NULL != kern_regs) {
 167                 /* Kernel was interrupted. */
 168                 dtrace_probe(prof->prof_id, saved_state64(kern_regs)->isf.rip,  0x0, late, 0, 0);
 169
 170         } else {
 171                 pal_register_cache_state(current_thread(), VALID);
 172                 /* Possibly a user interrupt */
 173                 x86_saved_state_t   *tagged_regs = (x86_saved_state_t *)find_user_regs(current_thread());
 174
 175                 if (NULL == tagged_regs) {
 176                         /* Too bad, so sad, no useful interrupt state. */
 177                         dtrace_probe(prof->prof_id, 0xcafebabe,
 178                         0x0, late, 0, 0); /* XXX_BOGUS also see profile_usermode() below. */
 179                 } else if (is_saved_state64(tagged_regs)) {
 180                         x86_saved_state64_t *regs = saved_state64(tagged_regs);
 181
 182                         dtrace_probe(prof->prof_id, 0x0, regs->isf.rip, late, 0, 0);
 183                 } else {
 184                         x86_saved_state32_t *regs = saved_state32(tagged_regs);
 185
 186                         dtrace_probe(prof->prof_id, 0x0, regs->eip, late, 0, 0);
 187                 }
 188         }
 189 #else
 190 #error Unknown architecture
 191 #endif
 192 }
 193
 194 static void
 195 profile_tick(void *arg)
 196 {
 197         profile_probe_t *prof = arg;
 198
 199 #if defined(__x86_64__)
 200         x86_saved_state_t *kern_regs = find_kern_regs(current_thread());
 201
 202         if (NULL != kern_regs) {
 203                 /* Kernel was interrupted. */
 204                 dtrace_probe(prof->prof_id, saved_state64(kern_regs)->isf.rip,  0x0, 0, 0, 0);
 205         } else {
 206                 pal_register_cache_state(current_thread(), VALID);
 207                 /* Possibly a user interrupt */
 208                 x86_saved_state_t   *tagged_regs = (x86_saved_state_t *)find_user_regs(current_thread());
 209
 210                 if (NULL == tagged_regs) {
 211                         /* Too bad, so sad, no useful interrupt state. */
 212                         dtrace_probe(prof->prof_id, 0xcafebabe,
 213                         0x0, 0, 0, 0); /* XXX_BOGUS also see profile_usermode() below. */
 214                 } else if (is_saved_state64(tagged_regs)) {
 215                         x86_saved_state64_t *regs = saved_state64(tagged_regs);
 216
 217                         dtrace_probe(prof->prof_id, 0x0, regs->isf.rip, 0, 0, 0);
 218                 } else {
 219                         x86_saved_state32_t *regs = saved_state32(tagged_regs);
 220
 221                         dtrace_probe(prof->prof_id, 0x0, regs->eip, 0, 0, 0);
 222                 }
 223         }
 224 #else
 225 #error Unknown architecture
 226 #endif
 227 }
 228
 229 static void
 230 profile_create(hrtime_t interval, const char *name, int kind)
 231 {
 232         profile_probe_t *prof;
 233
 234         if (interval < profile_interval_min)
 235                 return;
 236
 237         if (dtrace_probe_lookup(profile_id, NULL, NULL, name) != 0)
 238                 return;
 239
 240         atomic_add_32(&profile_total, 1);
 241         if (profile_total > profile_max) {
 242                 atomic_add_32(&profile_total, -1);
 243                 return;
 244         }
 245
 246         if (PROF_TICK == kind)
 247                 prof = kmem_zalloc(sizeof (profile_probe_t), KM_SLEEP);
 248         else
 249                 prof = kmem_zalloc(sizeof (profile_probe_t) + NCPU*sizeof(profile_probe_percpu_t), KM_SLEEP);
 250
 251         (void) strlcpy(prof->prof_name, name, sizeof(prof->prof_name));
 252         prof->prof_interval = interval;
 253         prof->prof_cyclic = CYCLIC_NONE;
 254         prof->prof_kind = kind;
 255         prof->prof_id = dtrace_probe_create(profile_id,
 256             NULL, NULL, name,
 257             profile_aframes ? profile_aframes : PROF_ARTIFICIAL_FRAMES, prof);
 258 }
 259
 260 /*ARGSUSED*/
 261 static void
 262 profile_provide(void *arg, const dtrace_probedesc_t *desc)
 263 {
 264 #pragma unused(arg) /* __APPLE__ */
 265         int i, j, rate, kind;
 266         hrtime_t val = 0, mult = 1, len;
 267         const char *name, *suffix = NULL;
 268
 269         const struct {
 270                 const char *prefix;
 271                 int kind;
 272         } types[] = {
 273                 { PROF_PREFIX_PROFILE, PROF_PROFILE },
 274                 { PROF_PREFIX_TICK, PROF_TICK },
 275                 { NULL, 0 }
 276         };
 277
 278         const struct {
 279                 const char *name;
 280                 hrtime_t mult;
 281         } suffixes[] = {
 282                 { "ns",         NANOSEC / NANOSEC },
 283                 { "nsec",       NANOSEC / NANOSEC },
 284                 { "us",         NANOSEC / MICROSEC },
 285                 { "usec",       NANOSEC / MICROSEC },
 286                 { "ms",         NANOSEC / MILLISEC },
 287                 { "msec",       NANOSEC / MILLISEC },
 288                 { "s",          NANOSEC / SEC },
 289                 { "sec",        NANOSEC / SEC },
 290                 { "m",          NANOSEC * (hrtime_t)60 },
 291                 { "min",        NANOSEC * (hrtime_t)60 },
 292                 { "h",          NANOSEC * (hrtime_t)(60 * 60) },
 293                 { "hour",       NANOSEC * (hrtime_t)(60 * 60) },
 294                 { "d",          NANOSEC * (hrtime_t)(24 * 60 * 60) },
 295                 { "day",        NANOSEC * (hrtime_t)(24 * 60 * 60) },
 296                 { "hz",         0 },
 297                 { NULL, 0 }
 298         };
 299
 300         if (desc == NULL) {
 301                 char n[PROF_NAMELEN];
 302
 303                 /*
 304                  * If no description was provided, provide all of our probes.
 305                  */
 306                 for (i = 0; i < (int)(sizeof (profile_rates) / sizeof (int)); i++) {
 307                         if ((rate = profile_rates[i]) == 0)
 308                                 continue;
 309
 310                         (void) snprintf(n, PROF_NAMELEN, "%s%d",
 311                             PROF_PREFIX_PROFILE, rate);
 312                         profile_create(NANOSEC / rate, n, PROF_PROFILE);
 313                 }
 314
 315                 for (i = 0; i < (int)(sizeof (profile_ticks) / sizeof (int)); i++) {
 316                         if ((rate = profile_ticks[i]) == 0)
 317                                 continue;
 318
 319                         (void) snprintf(n, PROF_NAMELEN, "%s%d",
 320                             PROF_PREFIX_TICK, rate);
 321                         profile_create(NANOSEC / rate, n, PROF_TICK);
 322                 }
 323
 324                 return;
 325         }
 326
 327         name = desc->dtpd_name;
 328
 329         for (i = 0; types[i].prefix != NULL; i++) {
 330                 len = strlen(types[i].prefix);
 331
 332                 if (strncmp(name, types[i].prefix, len) != 0)
 333                         continue;
 334                 break;
 335         }
 336
 337         if (types[i].prefix == NULL)
 338                 return;
 339
 340         kind = types[i].kind;
 341         j = strlen(name) - len;
 342
 343         /*
 344          * We need to start before any time suffix.
 345          */
 346         for (j = strlen(name); j >= len; j--) {
 347                 if (name[j] >= '0' && name[j] <= '9')
 348                         break;
 349                 suffix = &name[j];
 350         }
 351
 352         ASSERT(suffix != NULL);
 353
 354         /*
 355          * Now determine the numerical value present in the probe name.
 356          */
 357         for (; j >= len; j--) {
 358                 if (name[j] < '0' || name[j] > '9')
 359                         return;
 360
 361                 val += (name[j] - '0') * mult;
 362                 mult *= (hrtime_t)10;
 363         }
 364
 365         if (val == 0)
 366                 return;
 367
 368         /*
 369          * Look-up the suffix to determine the multiplier.
 370          */
 371         for (i = 0, mult = 0; suffixes[i].name != NULL; i++) {
 372                 /* APPLE NOTE: Darwin employs size bounded string operations */
 373                 if (strncasecmp(suffixes[i].name, suffix, strlen(suffixes[i].name) + 1) == 0) {
 374                         mult = suffixes[i].mult;
 375                         break;
 376                 }
 377         }
 378
 379         if (suffixes[i].name == NULL && *suffix != '\0')
 380                 return;
 381
 382         if (mult == 0) {
 383                 /*
 384                  * The default is frequency-per-second.
 385                  */
 386                 val = NANOSEC / val;
 387         } else {
 388                 val *= mult;
 389         }
 390
 391         profile_create(val, name, kind);
 392 }
 393
 394 /*ARGSUSED*/
 395 static void
 396 profile_destroy(void *arg, dtrace_id_t id, void *parg)
 397 {
 398 #pragma unused(arg,id) /* __APPLE__ */
 399         profile_probe_t *prof = parg;
 400
 401         ASSERT(prof->prof_cyclic == CYCLIC_NONE);
 402
 403         if (prof->prof_kind == PROF_TICK)
 404                 kmem_free(prof, sizeof (profile_probe_t));
 405         else
 406                 kmem_free(prof, sizeof (profile_probe_t) + NCPU*sizeof(profile_probe_percpu_t));
 407
 408         ASSERT(profile_total >= 1);
 409         atomic_add_32(&profile_total, -1);
 410 }
 411
 412 /*ARGSUSED*/
 413 static void
 414 profile_online(void *arg, dtrace_cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when)
 415 {
 416 #pragma unused(cpu) /* __APPLE__ */
 417         profile_probe_t *prof = arg;
 418         profile_probe_percpu_t *pcpu;
 419
 420         pcpu = ((profile_probe_percpu_t *)(&(prof[1]))) + cpu_number();
 421         pcpu->profc_probe = prof;
 422
 423         hdlr->cyh_func = profile_fire;
 424         hdlr->cyh_arg = pcpu;
 425         hdlr->cyh_level = CY_HIGH_LEVEL;
 426
 427         when->cyt_interval = prof->prof_interval;
 428         when->cyt_when = dtrace_gethrtime() + when->cyt_interval;
 429
 430         pcpu->profc_expected = when->cyt_when;
 431         pcpu->profc_interval = when->cyt_interval;
 432 }
 433
 434 /*ARGSUSED*/
 435 static void
 436 profile_offline(void *arg, dtrace_cpu_t *cpu, void *oarg)
 437 {
 438         profile_probe_percpu_t *pcpu = oarg;
 439
 440         ASSERT(pcpu->profc_probe == arg);
 441 #pragma unused(pcpu,arg,cpu) /* __APPLE__ */
 442 }
 443
 444 /*ARGSUSED*/
 445 static int
 446 profile_enable(void *arg, dtrace_id_t id, void *parg)
 447 {
 448 #pragma unused(arg,id) /* __APPLE__ */
 449         profile_probe_t *prof = parg;
 450         cyc_omni_handler_t omni;
 451         cyc_handler_t hdlr;
 452         cyc_time_t when;
 453
 454         ASSERT(prof->prof_interval != 0);
 455         ASSERT(MUTEX_HELD(&cpu_lock));
 456
 457         if (prof->prof_kind == PROF_TICK) {
 458                 hdlr.cyh_func = profile_tick;
 459                 hdlr.cyh_arg = prof;
 460                 hdlr.cyh_level = CY_HIGH_LEVEL;
 461
 462                 when.cyt_interval = prof->prof_interval;
 463 #if !defined(__APPLE__)
 464                 when.cyt_when = dtrace_gethrtime() + when.cyt_interval;
 465 #else
 466                 when.cyt_when = 0;
 467 #endif /* __APPLE__ */
 468         } else {
 469                 ASSERT(prof->prof_kind == PROF_PROFILE);
 470                 omni.cyo_online = profile_online;
 471                 omni.cyo_offline = profile_offline;
 472                 omni.cyo_arg = prof;
 473         }
 474
 475         if (prof->prof_kind == PROF_TICK) {
 476                 prof->prof_cyclic = cyclic_timer_add(&hdlr, &when);
 477         } else {
 478                 prof->prof_cyclic = (cyclic_id_t)cyclic_add_omni(&omni); /* cast puns cyclic_id_list_t with cyclic_id_t */
 479         }
 480
 481         return(0);
 482 }
 483
 484 /*ARGSUSED*/
 485 static void
 486 profile_disable(void *arg, dtrace_id_t id, void *parg)
 487 {
 488         profile_probe_t *prof = parg;
 489
 490         ASSERT(prof->prof_cyclic != CYCLIC_NONE);
 491         ASSERT(MUTEX_HELD(&cpu_lock));
 492
 493 #pragma unused(arg,id)
 494         if (prof->prof_kind == PROF_TICK) {
 495                 cyclic_timer_remove(prof->prof_cyclic);
 496         } else {
 497                 cyclic_remove_omni((cyclic_id_list_t)prof->prof_cyclic); /* cast puns cyclic_id_list_t with cyclic_id_t */
 498         }
 499         prof->prof_cyclic = CYCLIC_NONE;
 500 }
 501
 502 /*
 503  * APPLE NOTE:  profile_usermode call not supported.
 504  */
 505 static int
 506 profile_usermode(void *arg, dtrace_id_t id, void *parg)
 507 {
 508 #pragma unused(arg,id,parg)
 509         return 1; /* XXX_BOGUS */
 510 }
 511
 512 static dtrace_pattr_t profile_attr = {
 513 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 514 { DTRACE_STABILITY_UNSTABLE, DTRACE_STABILITY_UNSTABLE, DTRACE_CLASS_UNKNOWN },
 515 { DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN },
 516 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 517 { DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON },
 518 };
 519
 520 static dtrace_pops_t profile_pops = {
 521         profile_provide,
 522         NULL,
 523         profile_enable,
 524         profile_disable,
 525         NULL,
 526         NULL,
 527         NULL,
 528         NULL,
 529         profile_usermode,
 530         profile_destroy
 531 };
 532
 533 static int
 534 profile_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
 535 {
 536         switch (cmd) {
 537         case DDI_ATTACH:
 538                 break;
 539         case DDI_RESUME:
 540                 return (DDI_SUCCESS);
 541         default:
 542                 return (DDI_FAILURE);
 543         }
 544
 545         if (ddi_create_minor_node(devi, "profile", S_IFCHR, 0,
 546             DDI_PSEUDO, 0) == DDI_FAILURE ||
 547             dtrace_register("profile", &profile_attr,
 548             DTRACE_PRIV_KERNEL | DTRACE_PRIV_USER, NULL,
 549             &profile_pops, NULL, &profile_id) != 0) {
 550                 ddi_remove_minor_node(devi, NULL);
 551                 return (DDI_FAILURE);
 552         }
 553
 554         profile_max = PROFILE_MAX_DEFAULT;
 555
 556         ddi_report_dev(devi);
 557         profile_devi = devi;
 558         return (DDI_SUCCESS);
 559 }
 560
 561 /*
 562  * APPLE NOTE:  profile_detach not implemented
 563  */
 564 #if !defined(__APPLE__)
 565 static int
 566 profile_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
 567 {
 568         switch (cmd) {
 569         case DDI_DETACH:
 570                 break;
 571         case DDI_SUSPEND:
 572                 return (DDI_SUCCESS);
 573         default:
 574                 return (DDI_FAILURE);
 575         }
 576
 577         if (dtrace_unregister(profile_id) != 0)
 578                 return (DDI_FAILURE);
 579
 580         ddi_remove_minor_node(devi, NULL);
 581         return (DDI_SUCCESS);
 582 }
 583 #endif /* __APPLE__ */
 584
 585 d_open_t _profile_open;
 586
 587 int _profile_open(dev_t dev, int flags, int devtype, struct proc *p)
 588 {
 589 #pragma unused(dev,flags,devtype,p)
 590         return 0;
 591 }
 592
 593 #define PROFILE_MAJOR  -24 /* let the kernel pick the device number */
 594
 595 /*
 596  * A struct describing which functions will get invoked for certain
 597  * actions.
 598  */
 599 static struct cdevsw profile_cdevsw =
 600 {
 601         _profile_open,          /* open */
 602         eno_opcl,                       /* close */
 603         eno_rdwrt,                      /* read */
 604         eno_rdwrt,                      /* write */
 605         eno_ioctl,                      /* ioctl */
 606         (stop_fcn_t *)nulldev, /* stop */
 607         (reset_fcn_t *)nulldev, /* reset */
 608         NULL,                           /* tty's */
 609         eno_select,                     /* select */
 610         eno_mmap,                       /* mmap */
 611         eno_strat,                      /* strategy */
 612         eno_getc,                       /* getc */
 613         eno_putc,                       /* putc */
 614         0                                       /* type */
 615 };
 616
 617 static int gProfileInited = 0;
 618
 619 void profile_init( void )
 620 {
 621         if (0 == gProfileInited)
 622         {
 623                 int majdevno = cdevsw_add(PROFILE_MAJOR, &profile_cdevsw);
 624
 625                 if (majdevno < 0) {
 626                         printf("profile_init: failed to allocate a major number!\n");
 627                         gProfileInited = 0;
 628                         return;
 629                 }
 630
 631                 profile_attach( (dev_info_t     *)(uintptr_t)majdevno, DDI_ATTACH );
 632
 633                 gProfileInited = 1;
 634         } else
 635                 panic("profile_init: called twice!\n");
 636 }
 637 #undef PROFILE_MAJOR