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