bsd/dev/dtrace/sdt.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 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /* #pragma ident        "@(#)sdt.c      1.9     08/07/01 SMI" */
  27
  28 #ifdef KERNEL
  29 #ifndef _KERNEL
  30 #define _KERNEL /* Solaris vs. Darwin */
  31 #endif
  32 #endif
  33
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/errno.h>
  37 #include <sys/stat.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/conf.h>
  40 #include <sys/fcntl.h>
  41 #include <miscfs/devfs/devfs.h>
  42
  43 #if CONFIG_EMBEDDED
  44 #include <arm/caches_internal.h>
  45 #endif
  46
  47 #include <sys/dtrace.h>
  48 #include <sys/dtrace_impl.h>
  49
  50 #include <sys/dtrace_glue.h>
  51
  52 #include <sys/sdt_impl.h>
  53 extern int dtrace_kernel_symbol_mode;
  54
  55 /* #include <machine/trap.h */
  56 struct savearea_t; /* Used anonymously */
  57
  58 #if defined(__arm__)
  59 typedef kern_return_t (*perfCallback)(int, struct savearea_t *, __unused int, __unused int);
  60 extern perfCallback tempDTraceTrapHook;
  61 extern kern_return_t fbt_perfCallback(int, struct savearea_t *, __unused int, __unused int);
  62 #define SDT_PATCHVAL    0xdefc
  63 #define SDT_AFRAMES             7
  64 #elif defined(__arm64__)
  65 typedef kern_return_t (*perfCallback)(int, struct savearea_t *, __unused int, __unused int);
  66 extern perfCallback tempDTraceTrapHook;
  67 extern kern_return_t fbt_perfCallback(int, struct savearea_t *, __unused int, __unused int);
  68 #define SDT_PATCHVAL    0xe7eeee7e
  69 #define SDT_AFRAMES             7
  70 #elif defined(__x86_64__)
  71 typedef kern_return_t (*perfCallback)(int, struct savearea_t *, uintptr_t *, int);
  72 extern perfCallback tempDTraceTrapHook;
  73 extern kern_return_t fbt_perfCallback(int, struct savearea_t *, uintptr_t *, int);
  74 #define SDT_PATCHVAL    0xf0
  75 #define SDT_AFRAMES             6
  76 #else
  77 #error Unknown architecture
  78 #endif
  79
  80 #define SDT_PROBETAB_SIZE       0x1000          /* 4k entries -- 16K total */
  81
  82 #define DTRACE_PROBE_PREFIX "_dtrace_probe$"
  83
  84 static int                      sdt_verbose = 0;
  85 sdt_probe_t             **sdt_probetab;
  86 int                     sdt_probetab_size;
  87 int                     sdt_probetab_mask;
  88
  89 /*ARGSUSED*/
  90 static void
  91 __sdt_provide_module(void *arg, struct modctl *ctl)
  92 {
  93 #pragma unused(arg)
  94         struct module *mp = (struct module *)ctl->mod_address;
  95         char *modname = ctl->mod_modname;
  96         sdt_probedesc_t *sdpd;
  97         sdt_probe_t *sdp, *old;
  98         sdt_provider_t *prov;
  99         int len;
 100
 101         /*
 102          * One for all, and all for one:  if we haven't yet registered all of
 103          * our providers, we'll refuse to provide anything.
 104          */
 105         for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
 106                 if (prov->sdtp_id == DTRACE_PROVNONE)
 107                         return;
 108         }
 109
 110         if (!mp || mp->sdt_nprobes != 0 || (sdpd = mp->sdt_probes) == NULL)
 111                 return;
 112
 113         for (sdpd = mp->sdt_probes; sdpd != NULL; sdpd = sdpd->sdpd_next) {
 114             const char *name = sdpd->sdpd_name, *func;
 115             char *nname;
 116                 int i, j;
 117                 dtrace_id_t id;
 118
 119                 for (prov = sdt_providers; prov->sdtp_prefix != NULL; prov++) {
 120                         const char *prefpart, *prefix = prov->sdtp_prefix;
 121
 122                         if ((prefpart = strstr(name, prefix))) {
 123                                 name = prefpart + strlen(prefix);
 124                                 break;
 125                         }
 126                 }
 127
 128                 nname = kmem_alloc(len = strlen(name) + 1, KM_SLEEP);
 129
 130                 for (i = 0, j = 0; name[j] != '\0'; i++) {
 131                         if (name[j] == '_' && name[j + 1] == '_') {
 132                                 nname[i] = '-';
 133                                 j += 2;
 134                         } else {
 135                                 nname[i] = name[j++];
 136                         }
 137                 }
 138
 139                 nname[i] = '\0';
 140
 141                 sdp = kmem_zalloc(sizeof (sdt_probe_t), KM_SLEEP);
 142                 sdp->sdp_loadcnt = ctl->mod_loadcnt;
 143                 sdp->sdp_ctl = ctl;
 144                 sdp->sdp_name = nname;
 145                 sdp->sdp_namelen = len;
 146                 sdp->sdp_provider = prov;
 147
 148                 func = sdpd->sdpd_func;
 149
 150                 if (func == NULL)
 151                         func = "<unknown>";
 152
 153                 /*
 154                  * We have our provider.  Now create the probe.
 155                  */
 156                 if ((id = dtrace_probe_lookup(prov->sdtp_id, modname,
 157                     func, nname)) != DTRACE_IDNONE) {
 158                         old = dtrace_probe_arg(prov->sdtp_id, id);
 159                         ASSERT(old != NULL);
 160
 161                         sdp->sdp_next = old->sdp_next;
 162                         sdp->sdp_id = id;
 163                         old->sdp_next = sdp;
 164                 } else {
 165                         sdp->sdp_id = dtrace_probe_create(prov->sdtp_id,
 166                             modname, func, nname, SDT_AFRAMES, sdp);
 167
 168                         mp->sdt_nprobes++;
 169                 }
 170
 171 #if 0
 172                 printf ("__sdt_provide_module:  sdpd=0x%p  sdp=0x%p  name=%s, id=%d\n", sdpd, sdp, nname, sdp->sdp_id);
 173 #endif
 174
 175                 sdp->sdp_hashnext =
 176                     sdt_probetab[SDT_ADDR2NDX(sdpd->sdpd_offset)];
 177                 sdt_probetab[SDT_ADDR2NDX(sdpd->sdpd_offset)] = sdp;
 178
 179                 sdp->sdp_patchval = SDT_PATCHVAL;
 180                 sdp->sdp_patchpoint = (sdt_instr_t *)sdpd->sdpd_offset;
 181                 sdp->sdp_savedval = *sdp->sdp_patchpoint;
 182         }
 183 }
 184
 185 /*ARGSUSED*/
 186 static void
 187 sdt_destroy(void *arg, dtrace_id_t id, void *parg)
 188 {
 189 #pragma unused(arg,id)
 190         sdt_probe_t *sdp = parg, *old, *last, *hash;
 191         int ndx;
 192
 193 #if !defined(__APPLE__)
 194         /*
 195          * APPLE NOTE:  sdt probes for kexts not yet implemented
 196          */
 197         struct modctl *ctl = sdp->sdp_ctl;
 198
 199         if (ctl != NULL && ctl->mod_loadcnt == sdp->sdp_loadcnt) {
 200                 if ((ctl->mod_loadcnt == sdp->sdp_loadcnt &&
 201                     ctl->mod_loaded)) {
 202                         ((struct module *)(ctl->mod_mp))->sdt_nprobes--;
 203                 }
 204         }
 205 #endif /* __APPLE__ */
 206
 207         while (sdp != NULL) {
 208                 old = sdp;
 209
 210                 /*
 211                  * Now we need to remove this probe from the sdt_probetab.
 212                  */
 213                 ndx = SDT_ADDR2NDX(sdp->sdp_patchpoint);
 214                 last = NULL;
 215                 hash = sdt_probetab[ndx];
 216
 217                 while (hash != sdp) {
 218                         ASSERT(hash != NULL);
 219                         last = hash;
 220                         hash = hash->sdp_hashnext;
 221                 }
 222
 223                 if (last != NULL) {
 224                         last->sdp_hashnext = sdp->sdp_hashnext;
 225                 } else {
 226                         sdt_probetab[ndx] = sdp->sdp_hashnext;
 227                 }
 228
 229                 kmem_free(sdp->sdp_name, sdp->sdp_namelen);
 230                 sdp = sdp->sdp_next;
 231                 kmem_free(old, sizeof (sdt_probe_t));
 232         }
 233 }
 234
 235 /*ARGSUSED*/
 236 static int
 237 sdt_enable(void *arg, dtrace_id_t id, void *parg)
 238 {
 239 #pragma unused(arg,id)
 240         sdt_probe_t *sdp = parg;
 241         struct modctl *ctl = sdp->sdp_ctl;
 242
 243         ctl->mod_nenabled++;
 244
 245         /*
 246          * If this module has disappeared since we discovered its probes,
 247          * refuse to enable it.
 248          */
 249         if (!ctl->mod_loaded) {
 250                 if (sdt_verbose) {
 251                         cmn_err(CE_NOTE, "sdt is failing for probe %s "
 252                             "(module %s unloaded)",
 253                             sdp->sdp_name, ctl->mod_modname);
 254                 }
 255                 goto err;
 256         }
 257
 258         /*
 259          * Now check that our modctl has the expected load count.  If it
 260          * doesn't, this module must have been unloaded and reloaded -- and
 261          * we're not going to touch it.
 262          */
 263         if (ctl->mod_loadcnt != sdp->sdp_loadcnt) {
 264                 if (sdt_verbose) {
 265                         cmn_err(CE_NOTE, "sdt is failing for probe %s "
 266                             "(module %s reloaded)",
 267                             sdp->sdp_name, ctl->mod_modname);
 268                 }
 269                 goto err;
 270         }
 271
 272         dtrace_casptr(&tempDTraceTrapHook, NULL, fbt_perfCallback);
 273         if (tempDTraceTrapHook != (perfCallback)fbt_perfCallback) {
 274                 if (sdt_verbose) {
 275                         cmn_err(CE_NOTE, "sdt_enable is failing for probe %s "
 276                             "in module %s: tempDTraceTrapHook already occupied.",
 277                             sdp->sdp_name, ctl->mod_modname);
 278                 }
 279                 return (0);
 280         }
 281
 282         while (sdp != NULL) {
 283                 (void)ml_nofault_copy( (vm_offset_t)&sdp->sdp_patchval, (vm_offset_t)sdp->sdp_patchpoint,
 284                                        (vm_size_t)sizeof(sdp->sdp_patchval));
 285
 286                 /*
 287                  * Make the patched instruction visible via a data + instruction
 288                  * cache fush on platforms that need it
 289                  */
 290                 flush_dcache((vm_offset_t)sdp->sdp_patchpoint,(vm_size_t)sizeof(sdp->sdp_patchval), 0);
 291                 invalidate_icache((vm_offset_t)sdp->sdp_patchpoint,(vm_size_t)sizeof(sdp->sdp_patchval), 0);
 292
 293                 sdp = sdp->sdp_next;
 294         }
 295
 296 err:
 297         return (0);
 298 }
 299
 300 /*ARGSUSED*/
 301 static void
 302 sdt_disable(void *arg, dtrace_id_t id, void *parg)
 303 {
 304 #pragma unused(arg,id)
 305         sdt_probe_t *sdp = parg;
 306         struct modctl *ctl = sdp->sdp_ctl;
 307
 308         ctl->mod_nenabled--;
 309
 310         if (!ctl->mod_loaded || ctl->mod_loadcnt != sdp->sdp_loadcnt)
 311                 goto err;
 312
 313         while (sdp != NULL) {
 314                 (void)ml_nofault_copy( (vm_offset_t)&sdp->sdp_savedval, (vm_offset_t)sdp->sdp_patchpoint,
 315                                        (vm_size_t)sizeof(sdp->sdp_savedval));
 316                 /*
 317                  * Make the patched instruction visible via a data + instruction
 318                  * cache flush on platforms that need it
 319                  */
 320                 flush_dcache((vm_offset_t)sdp->sdp_patchpoint,(vm_size_t)sizeof(sdp->sdp_savedval), 0);
 321                 invalidate_icache((vm_offset_t)sdp->sdp_patchpoint,(vm_size_t)sizeof(sdp->sdp_savedval), 0);
 322                 sdp = sdp->sdp_next;
 323         }
 324
 325 err:
 326         ;
 327 }
 328
 329 static dtrace_pops_t sdt_pops = {
 330         .dtps_provide =         NULL,
 331         .dtps_provide_module =  sdt_provide_module,
 332         .dtps_enable =          sdt_enable,
 333         .dtps_disable =         sdt_disable,
 334         .dtps_suspend =         NULL,
 335         .dtps_resume =          NULL,
 336         .dtps_getargdesc =      sdt_getargdesc,
 337         .dtps_getargval =       sdt_getarg,
 338         .dtps_usermode =        NULL,
 339         .dtps_destroy =         sdt_destroy,
 340 };
 341
 342 /*ARGSUSED*/
 343 static int
 344 sdt_attach(dev_info_t *devi)
 345 {
 346         sdt_provider_t *prov;
 347
 348         if (ddi_create_minor_node(devi, "sdt", S_IFCHR,
 349             0, DDI_PSEUDO, 0) == DDI_FAILURE) {
 350                 cmn_err(CE_NOTE, "/dev/sdt couldn't create minor node");
 351                 ddi_remove_minor_node(devi, NULL);
 352                 return (DDI_FAILURE);
 353         }
 354
 355         if (sdt_probetab_size == 0)
 356                 sdt_probetab_size = SDT_PROBETAB_SIZE;
 357
 358         sdt_probetab_mask = sdt_probetab_size - 1;
 359         sdt_probetab =
 360             kmem_zalloc(sdt_probetab_size * sizeof (sdt_probe_t *), KM_SLEEP);
 361         dtrace_invop_add(sdt_invop);
 362
 363         for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
 364                 if (dtrace_register(prov->sdtp_name, prov->sdtp_attr,
 365                     DTRACE_PRIV_KERNEL, NULL,
 366                     &sdt_pops, prov, &prov->sdtp_id) != 0) {
 367                         cmn_err(CE_WARN, "failed to register sdt provider %s",
 368                             prov->sdtp_name);
 369                 }
 370         }
 371
 372         return (DDI_SUCCESS);
 373 }
 374
 375 /*
 376  * APPLE NOTE:  sdt_detach not implemented
 377  */
 378 #if !defined(__APPLE__)
 379 /*ARGSUSED*/
 380 static int
 381 sdt_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
 382 {
 383         sdt_provider_t *prov;
 384
 385         switch (cmd) {
 386         case DDI_DETACH:
 387                 break;
 388
 389         case DDI_SUSPEND:
 390                 return (DDI_SUCCESS);
 391
 392         default:
 393                 return (DDI_FAILURE);
 394         }
 395
 396         for (prov = sdt_providers; prov->sdtp_name != NULL; prov++) {
 397                 if (prov->sdtp_id != DTRACE_PROVNONE) {
 398                         if (dtrace_unregister(prov->sdtp_id) != 0)
 399                                 return (DDI_FAILURE);
 400
 401                         prov->sdtp_id = DTRACE_PROVNONE;
 402                 }
 403         }
 404
 405         dtrace_invop_remove(sdt_invop);
 406         kmem_free(sdt_probetab, sdt_probetab_size * sizeof (sdt_probe_t *));
 407
 408         return (DDI_SUCCESS);
 409 }
 410 #endif /* __APPLE__ */
 411
 412 d_open_t _sdt_open;
 413
 414 int _sdt_open(dev_t dev, int flags, int devtype, struct proc *p)
 415 {
 416 #pragma unused(dev,flags,devtype,p)
 417         return 0;
 418 }
 419
 420 #define SDT_MAJOR  -24 /* let the kernel pick the device number */
 421
 422 /*
 423  * A struct describing which functions will get invoked for certain
 424  * actions.
 425  */
 426 static struct cdevsw sdt_cdevsw =
 427 {
 428         _sdt_open,              /* open */
 429         eno_opcl,                       /* close */
 430         eno_rdwrt,                      /* read */
 431         eno_rdwrt,                      /* write */
 432         eno_ioctl,                      /* ioctl */
 433         (stop_fcn_t *)nulldev, /* stop */
 434         (reset_fcn_t *)nulldev, /* reset */
 435         NULL,                           /* tty's */
 436         eno_select,                     /* select */
 437         eno_mmap,                       /* mmap */
 438         eno_strat,                      /* strategy */
 439         eno_getc,                       /* getc */
 440         eno_putc,                       /* putc */
 441         0                                       /* type */
 442 };
 443
 444 static struct modctl g_sdt_kernctl;
 445 static struct module g_sdt_mach_module;
 446
 447 #include <mach-o/nlist.h>
 448 #include <libkern/kernel_mach_header.h>
 449
 450 void sdt_early_init( void )
 451 {
 452         if (dtrace_sdt_probes_restricted()) {
 453                 return;
 454         }
 455         if (MH_MAGIC_KERNEL != _mh_execute_header.magic) {
 456                 g_sdt_kernctl.mod_address = (vm_address_t)NULL;
 457                 g_sdt_kernctl.mod_size = 0;
 458         } else {
 459                 kernel_mach_header_t        *mh;
 460                 struct load_command         *cmd;
 461                 kernel_segment_command_t    *orig_ts = NULL, *orig_le = NULL;
 462                 struct symtab_command       *orig_st = NULL;
 463                 kernel_nlist_t              *sym = NULL;
 464                 char                        *strings;
 465                 unsigned int                i;
 466
 467                 g_sdt_mach_module.sdt_nprobes = 0;
 468                 g_sdt_mach_module.sdt_probes = NULL;
 469
 470                 g_sdt_kernctl.mod_address = (vm_address_t)&g_sdt_mach_module;
 471                 g_sdt_kernctl.mod_size = 0;
 472                 strncpy((char *)&(g_sdt_kernctl.mod_modname), "mach_kernel", KMOD_MAX_NAME);
 473
 474                 g_sdt_kernctl.mod_next = NULL;
 475                 g_sdt_kernctl.mod_stale = NULL;
 476                 g_sdt_kernctl.mod_id = 0;
 477                 g_sdt_kernctl.mod_loadcnt = 1;
 478                 g_sdt_kernctl.mod_loaded = 1;
 479                 g_sdt_kernctl.mod_flags = 0;
 480                 g_sdt_kernctl.mod_nenabled = 0;
 481
 482                 mh = &_mh_execute_header;
 483                 cmd = (struct load_command*) &mh[1];
 484                 for (i = 0; i < mh->ncmds; i++) {
 485                         if (cmd->cmd == LC_SEGMENT_KERNEL) {
 486                                 kernel_segment_command_t *orig_sg = (kernel_segment_command_t *) cmd;
 487
 488                                 if (LIT_STRNEQL(orig_sg->segname, SEG_TEXT))
 489                                         orig_ts = orig_sg;
 490                                 else if (LIT_STRNEQL(orig_sg->segname, SEG_LINKEDIT))
 491                                         orig_le = orig_sg;
 492                                 else if (LIT_STRNEQL(orig_sg->segname, ""))
 493                                         orig_ts = orig_sg; /* kexts have a single unnamed segment */
 494                         }
 495                         else if (cmd->cmd == LC_SYMTAB)
 496                                 orig_st = (struct symtab_command *) cmd;
 497
 498                         cmd = (struct load_command *) ((uintptr_t) cmd + cmd->cmdsize);
 499                 }
 500
 501                 if ((orig_ts == NULL) || (orig_st == NULL) || (orig_le == NULL))
 502                         return;
 503
 504                 sym = (kernel_nlist_t *)(orig_le->vmaddr + orig_st->symoff - orig_le->fileoff);
 505                 strings = (char *)(orig_le->vmaddr + orig_st->stroff - orig_le->fileoff);
 506
 507                 for (i = 0; i < orig_st->nsyms; i++) {
 508                         uint8_t n_type = sym[i].n_type & (N_TYPE | N_EXT);
 509                         char *name = strings + sym[i].n_un.n_strx;
 510                         const char *prev_name;
 511                         unsigned long best;
 512                         unsigned int j;
 513
 514                         /* Check that the symbol is a global and that it has a name. */
 515                         if (((N_SECT | N_EXT) != n_type && (N_ABS | N_EXT) != n_type))
 516                                 continue;
 517
 518                         if (0 == sym[i].n_un.n_strx) /* iff a null, "", name. */
 519                                 continue;
 520
 521                         /* Lop off omnipresent leading underscore. */
 522                         if (*name == '_')
 523                                 name += 1;
 524
 525                         if (strncmp(name, DTRACE_PROBE_PREFIX, sizeof(DTRACE_PROBE_PREFIX) - 1) == 0) {
 526                                 sdt_probedesc_t *sdpd = kmem_alloc(sizeof(sdt_probedesc_t), KM_SLEEP);
 527                                 int len = strlen(name) + 1;
 528
 529                                 sdpd->sdpd_name = kmem_alloc(len, KM_SLEEP);
 530                                 strncpy(sdpd->sdpd_name, name, len); /* NUL termination is ensured. */
 531
 532                                 prev_name = "<unknown>";
 533                                 best = 0;
 534
 535                                 /*
 536                                  * Find the symbol immediately preceding the sdt probe site just discovered,
 537                                  * that symbol names the function containing the sdt probe.
 538                                  */
 539                                 for (j = 0; j < orig_st->nsyms; j++) {
 540                                         uint8_t jn_type = sym[j].n_type & N_TYPE;
 541                                         char *jname = strings + sym[j].n_un.n_strx;
 542
 543                                         if ((N_SECT != jn_type && N_ABS != jn_type))
 544                                                 continue;
 545
 546                                         if (0 == sym[j].n_un.n_strx) /* iff a null, "", name. */
 547                                                 continue;
 548
 549                                         if (*jname == '_')
 550                                                 jname += 1;
 551
 552                                         if (*(unsigned long *)sym[i].n_value <= (unsigned long)sym[j].n_value)
 553                                                 continue;
 554
 555                                         if ((unsigned long)sym[j].n_value > best) {
 556                                                 best = (unsigned long)sym[j].n_value;
 557                                                 prev_name = jname;
 558                                         }
 559                                 }
 560
 561                                 sdpd->sdpd_func = kmem_alloc((len = strlen(prev_name) + 1), KM_SLEEP);
 562                                 strncpy(sdpd->sdpd_func, prev_name, len); /* NUL termination is ensured. */
 563
 564                                 sdpd->sdpd_offset = *(unsigned long *)sym[i].n_value;
 565 #if defined(__arm__)
 566                                 /* PR8353094 - mask off thumb-bit */
 567                                 sdpd->sdpd_offset &= ~0x1U;
 568 #elif defined(__arm64__)
 569                                 sdpd->sdpd_offset &= ~0x1LU;
 570 #endif  /* __arm__ */
 571
 572 #if 0
 573                                 printf("sdt_init: sdpd_offset=0x%lx, n_value=0x%lx, name=%s\n",
 574                                     sdpd->sdpd_offset,  *(unsigned long *)sym[i].n_value, name);
 575 #endif
 576
 577                                 sdpd->sdpd_next = g_sdt_mach_module.sdt_probes;
 578                                 g_sdt_mach_module.sdt_probes = sdpd;
 579                         } else {
 580                                 prev_name = name;
 581                         }
 582                 }
 583         }
 584 }
 585
 586 void sdt_init( void )
 587 {
 588         int majdevno = cdevsw_add(SDT_MAJOR, &sdt_cdevsw);
 589
 590         if (majdevno < 0) {
 591                 printf("sdt_init: failed to allocate a major number!\n");
 592                 return;
 593         }
 594
 595         if (dtrace_sdt_probes_restricted()) {
 596                 return;
 597         }
 598
 599         sdt_attach((dev_info_t*)(uintptr_t)majdevno);
 600 }
 601
 602 #undef SDT_MAJOR
 603
 604 /*ARGSUSED*/
 605 void
 606 sdt_provide_module(void *arg, struct modctl *ctl)
 607 {
 608 #pragma unused(arg)
 609         ASSERT(ctl != NULL);
 610         ASSERT(dtrace_kernel_symbol_mode != DTRACE_KERNEL_SYMBOLS_NEVER);
 611         LCK_MTX_ASSERT(&mod_lock, LCK_MTX_ASSERT_OWNED);
 612
 613         if (MOD_SDT_DONE(ctl))
 614                 return;
 615
 616         if (MOD_IS_MACH_KERNEL(ctl)) {
 617                 __sdt_provide_module(arg, &g_sdt_kernctl);
 618
 619                 sdt_probedesc_t *sdpd = g_sdt_mach_module.sdt_probes;
 620                 while (sdpd) {
 621                         sdt_probedesc_t *this_sdpd = sdpd;
 622                         kmem_free((void *)sdpd->sdpd_name, strlen(sdpd->sdpd_name) + 1);
 623                         kmem_free((void *)sdpd->sdpd_func, strlen(sdpd->sdpd_func) + 1);
 624                         sdpd = sdpd->sdpd_next;
 625                         kmem_free((void *)this_sdpd, sizeof(sdt_probedesc_t));
 626                 }
 627                 g_sdt_mach_module.sdt_probes = NULL;
 628         } else {
 629                 /*
 630                  * APPLE NOTE:  sdt probes for kexts not yet implemented
 631                  */
 632         }
 633
 634         /* Need to mark this module as completed */
 635         ctl->mod_flags |= MODCTL_SDT_PROBES_PROVIDED;
 636 }