xref: /netbsd-src/external/cddl/osnet/dist/lib/libdtrace/common/dt_module.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
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 #ifndef ELFSIZE
27 #define ELFSIZE ARCH_ELFSIZE
28 #endif
29 
30 #include <sys/types.h>
31 #if defined(sun)
32 #include <sys/modctl.h>
33 #include <sys/kobj.h>
34 #include <sys/kobj_impl.h>
35 #include <sys/sysmacros.h>
36 #include <sys/elf.h>
37 #include <sys/task.h>
38 #else
39 #include <sys/param.h>
40 #include <sys/linker.h>
41 #include <sys/stat.h>
42 #include <sys/sysctl.h>
43 #endif
44 
45 #include <unistd.h>
46 #if defined(sun)
47 #include <project.h>
48 #endif
49 #include <strings.h>
50 #include <stdlib.h>
51 #include <libelf.h>
52 #include <limits.h>
53 #include <assert.h>
54 #include <errno.h>
55 #include <dirent.h>
56 #if !defined(sun)
57 #include <fcntl.h>
58 #endif
59 
60 #include <dt_strtab.h>
61 #include <dt_module.h>
62 #include <dt_impl.h>
63 
64 static const char *dt_module_strtab; /* active strtab for qsort callbacks */
65 
66 static void
67 dt_module_symhash_insert(dt_module_t *dmp, const char *name, uint_t id)
68 {
69 	dt_sym_t *dsp = &dmp->dm_symchains[dmp->dm_symfree];
70 	uint_t h;
71 
72 	assert(dmp->dm_symfree < dmp->dm_nsymelems + 1);
73 
74 	dsp->ds_symid = id;
75 	h = dt_strtab_hash(name, NULL) % dmp->dm_nsymbuckets;
76 	dsp->ds_next = dmp->dm_symbuckets[h];
77 	dmp->dm_symbuckets[h] = dmp->dm_symfree++;
78 }
79 
80 static uint_t
81 dt_module_syminit32(dt_module_t *dmp)
82 {
83 #if STT_NUM != (STT_TLS + 1)
84 #error "STT_NUM has grown. update dt_module_syminit32()"
85 #endif
86 	Elf32_Sym *sym = dmp->dm_symtab.cts_data;
87 	const char *base = dmp->dm_strtab.cts_data;
88 	size_t ss_size = dmp->dm_strtab.cts_size;
89 	uint_t i, n = dmp->dm_nsymelems;
90 	uint_t asrsv = 0;
91 
92 	for (i = 0; i < n; i++, sym++) {
93 		const char *name = base + sym->st_name;
94 		uchar_t type = ELF32_ST_TYPE(sym->st_info);
95 
96 		if (type >= STT_NUM || type == STT_SECTION)
97 			continue; /* skip sections and unknown types */
98 
99 		if (sym->st_name == 0 || sym->st_name >= ss_size)
100 			continue; /* skip null or invalid names */
101 
102 		if (sym->st_value != 0 &&
103 		    (ELF32_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size)) {
104 			asrsv++; /* reserve space in the address map */
105 
106 #if !defined(sun)
107 			sym->st_value += (Elf_Addr) dmp->dm_reloc_offset;
108 #endif
109 		}
110 
111 		dt_module_symhash_insert(dmp, name, i);
112 	}
113 
114 	return (asrsv);
115 }
116 
117 static uint_t
118 dt_module_syminit64(dt_module_t *dmp)
119 {
120 #if STT_NUM != (STT_TLS + 1)
121 #error "STT_NUM has grown. update dt_module_syminit64()"
122 #endif
123 	Elf64_Sym *sym = dmp->dm_symtab.cts_data;
124 	const char *base = dmp->dm_strtab.cts_data;
125 	size_t ss_size = dmp->dm_strtab.cts_size;
126 	uint_t i, n = dmp->dm_nsymelems;
127 	uint_t asrsv = 0;
128 
129 	for (i = 0; i < n; i++, sym++) {
130 		const char *name = base + sym->st_name;
131 		uchar_t type = ELF64_ST_TYPE(sym->st_info);
132 
133 		if (type >= STT_NUM || type == STT_SECTION)
134 			continue; /* skip sections and unknown types */
135 
136 		if (sym->st_name == 0 || sym->st_name >= ss_size)
137 			continue; /* skip null or invalid names */
138 
139 		if (sym->st_value != 0 &&
140 		    (ELF64_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size)) {
141 			asrsv++; /* reserve space in the address map */
142 
143 #if !defined(sun)
144 			sym->st_value += (Elf_Addr) dmp->dm_reloc_offset;
145 #endif
146 		}
147 
148 		dt_module_symhash_insert(dmp, name, i);
149 	}
150 
151 	return (asrsv);
152 }
153 
154 /*
155  * Sort comparison function for 32-bit symbol address-to-name lookups.  We sort
156  * symbols by value.  If values are equal, we prefer the symbol that is
157  * non-zero sized, typed, not weak, or lexically first, in that order.
158  */
159 static int
160 dt_module_symcomp32(const void *lp, const void *rp)
161 {
162 	Elf32_Sym *lhs = *((Elf32_Sym **)lp);
163 	Elf32_Sym *rhs = *((Elf32_Sym **)rp);
164 
165 	if (lhs->st_value != rhs->st_value)
166 		return (lhs->st_value > rhs->st_value ? 1 : -1);
167 
168 	if ((lhs->st_size == 0) != (rhs->st_size == 0))
169 		return (lhs->st_size == 0 ? 1 : -1);
170 
171 	if ((ELF32_ST_TYPE(lhs->st_info) == STT_NOTYPE) !=
172 	    (ELF32_ST_TYPE(rhs->st_info) == STT_NOTYPE))
173 		return (ELF32_ST_TYPE(lhs->st_info) == STT_NOTYPE ? 1 : -1);
174 
175 	if ((ELF32_ST_BIND(lhs->st_info) == STB_WEAK) !=
176 	    (ELF32_ST_BIND(rhs->st_info) == STB_WEAK))
177 		return (ELF32_ST_BIND(lhs->st_info) == STB_WEAK ? 1 : -1);
178 
179 	return (strcmp(dt_module_strtab + lhs->st_name,
180 	    dt_module_strtab + rhs->st_name));
181 }
182 
183 /*
184  * Sort comparison function for 64-bit symbol address-to-name lookups.  We sort
185  * symbols by value.  If values are equal, we prefer the symbol that is
186  * non-zero sized, typed, not weak, or lexically first, in that order.
187  */
188 static int
189 dt_module_symcomp64(const void *lp, const void *rp)
190 {
191 	Elf64_Sym *lhs = *((Elf64_Sym **)lp);
192 	Elf64_Sym *rhs = *((Elf64_Sym **)rp);
193 
194 	if (lhs->st_value != rhs->st_value)
195 		return (lhs->st_value > rhs->st_value ? 1 : -1);
196 
197 	if ((lhs->st_size == 0) != (rhs->st_size == 0))
198 		return (lhs->st_size == 0 ? 1 : -1);
199 
200 	if ((ELF64_ST_TYPE(lhs->st_info) == STT_NOTYPE) !=
201 	    (ELF64_ST_TYPE(rhs->st_info) == STT_NOTYPE))
202 		return (ELF64_ST_TYPE(lhs->st_info) == STT_NOTYPE ? 1 : -1);
203 
204 	if ((ELF64_ST_BIND(lhs->st_info) == STB_WEAK) !=
205 	    (ELF64_ST_BIND(rhs->st_info) == STB_WEAK))
206 		return (ELF64_ST_BIND(lhs->st_info) == STB_WEAK ? 1 : -1);
207 
208 	return (strcmp(dt_module_strtab + lhs->st_name,
209 	    dt_module_strtab + rhs->st_name));
210 }
211 
212 static void
213 dt_module_symsort32(dt_module_t *dmp)
214 {
215 	Elf32_Sym *symtab = (Elf32_Sym *)dmp->dm_symtab.cts_data;
216 	Elf32_Sym **sympp = (Elf32_Sym **)dmp->dm_asmap;
217 	const dt_sym_t *dsp = dmp->dm_symchains + 1;
218 	uint_t i, n = dmp->dm_symfree;
219 
220 	for (i = 1; i < n; i++, dsp++) {
221 		Elf32_Sym *sym = symtab + dsp->ds_symid;
222 		if (sym->st_value != 0 &&
223 		    (ELF32_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size))
224 			*sympp++ = sym;
225 	}
226 
227 	dmp->dm_aslen = (uint_t)(sympp - (Elf32_Sym **)dmp->dm_asmap);
228 	assert(dmp->dm_aslen <= dmp->dm_asrsv);
229 
230 	dt_module_strtab = dmp->dm_strtab.cts_data;
231 	qsort(dmp->dm_asmap, dmp->dm_aslen,
232 	    sizeof (Elf32_Sym *), dt_module_symcomp32);
233 	dt_module_strtab = NULL;
234 }
235 
236 static void
237 dt_module_symsort64(dt_module_t *dmp)
238 {
239 	Elf64_Sym *symtab = (Elf64_Sym *)dmp->dm_symtab.cts_data;
240 	Elf64_Sym **sympp = (Elf64_Sym **)dmp->dm_asmap;
241 	const dt_sym_t *dsp = dmp->dm_symchains + 1;
242 	uint_t i, n = dmp->dm_symfree;
243 
244 	for (i = 1; i < n; i++, dsp++) {
245 		Elf64_Sym *sym = symtab + dsp->ds_symid;
246 		if (sym->st_value != 0 &&
247 		    (ELF64_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size))
248 			*sympp++ = sym;
249 	}
250 
251 	dmp->dm_aslen = (uint_t)(sympp - (Elf64_Sym **)dmp->dm_asmap);
252 	assert(dmp->dm_aslen <= dmp->dm_asrsv);
253 
254 	dt_module_strtab = dmp->dm_strtab.cts_data;
255 	qsort(dmp->dm_asmap, dmp->dm_aslen,
256 	    sizeof (Elf64_Sym *), dt_module_symcomp64);
257 	dt_module_strtab = NULL;
258 }
259 
260 static GElf_Sym *
261 dt_module_symgelf32(const Elf32_Sym *src, GElf_Sym *dst)
262 {
263 	if (dst != NULL) {
264 		dst->st_name = src->st_name;
265 		dst->st_info = src->st_info;
266 		dst->st_other = src->st_other;
267 		dst->st_shndx = src->st_shndx;
268 		dst->st_value = src->st_value;
269 		dst->st_size = src->st_size;
270 	}
271 
272 	return (dst);
273 }
274 
275 static GElf_Sym *
276 dt_module_symgelf64(const Elf64_Sym *src, GElf_Sym *dst)
277 {
278 	if (dst != NULL)
279 		bcopy(src, dst, sizeof (GElf_Sym));
280 
281 	return (dst);
282 }
283 
284 static GElf_Sym *
285 dt_module_symname32(dt_module_t *dmp, const char *name,
286     GElf_Sym *symp, uint_t *idp)
287 {
288 	const Elf32_Sym *symtab = dmp->dm_symtab.cts_data;
289 	const char *strtab = dmp->dm_strtab.cts_data;
290 
291 	const Elf32_Sym *sym;
292 	const dt_sym_t *dsp;
293 	uint_t i, h;
294 
295 	if (dmp->dm_nsymelems == 0)
296 		return (NULL);
297 
298 	h = dt_strtab_hash(name, NULL) % dmp->dm_nsymbuckets;
299 
300 	for (i = dmp->dm_symbuckets[h]; i != 0; i = dsp->ds_next) {
301 		dsp = &dmp->dm_symchains[i];
302 		sym = symtab + dsp->ds_symid;
303 
304 		if (strcmp(name, strtab + sym->st_name) == 0) {
305 			if (idp != NULL)
306 				*idp = dsp->ds_symid;
307 			return (dt_module_symgelf32(sym, symp));
308 		}
309 	}
310 
311 	return (NULL);
312 }
313 
314 static GElf_Sym *
315 dt_module_symname64(dt_module_t *dmp, const char *name,
316     GElf_Sym *symp, uint_t *idp)
317 {
318 	const Elf64_Sym *symtab = dmp->dm_symtab.cts_data;
319 	const char *strtab = dmp->dm_strtab.cts_data;
320 
321 	const Elf64_Sym *sym;
322 	const dt_sym_t *dsp;
323 	uint_t i, h;
324 
325 	if (dmp->dm_nsymelems == 0)
326 		return (NULL);
327 
328 	h = dt_strtab_hash(name, NULL) % dmp->dm_nsymbuckets;
329 
330 	for (i = dmp->dm_symbuckets[h]; i != 0; i = dsp->ds_next) {
331 		dsp = &dmp->dm_symchains[i];
332 		sym = symtab + dsp->ds_symid;
333 
334 		if (strcmp(name, strtab + sym->st_name) == 0) {
335 			if (idp != NULL)
336 				*idp = dsp->ds_symid;
337 			return (dt_module_symgelf64(sym, symp));
338 		}
339 	}
340 
341 	return (NULL);
342 }
343 
344 static GElf_Sym *
345 dt_module_symaddr32(dt_module_t *dmp, GElf_Addr addr,
346     GElf_Sym *symp, uint_t *idp)
347 {
348 	const Elf32_Sym **asmap = (const Elf32_Sym **)dmp->dm_asmap;
349 	const Elf32_Sym *symtab = dmp->dm_symtab.cts_data;
350 	const Elf32_Sym *sym;
351 
352 	uint_t i, mid, lo = 0, hi = dmp->dm_aslen - 1;
353 	Elf32_Addr v;
354 
355 	if (dmp->dm_aslen == 0)
356 		return (NULL);
357 
358 	while (hi - lo > 1) {
359 		mid = (lo + hi) / 2;
360 		if (addr >= asmap[mid]->st_value)
361 			lo = mid;
362 		else
363 			hi = mid;
364 	}
365 
366 	i = addr < asmap[hi]->st_value ? lo : hi;
367 	sym = asmap[i];
368 	v = sym->st_value;
369 
370 	/*
371 	 * If the previous entry has the same value, improve our choice.  The
372 	 * order of equal-valued symbols is determined by the comparison func.
373 	 */
374 	while (i-- != 0 && asmap[i]->st_value == v)
375 		sym = asmap[i];
376 
377 	if (addr - sym->st_value < MAX(sym->st_size, 1)) {
378 		if (idp != NULL)
379 			*idp = (uint_t)(sym - symtab);
380 		return (dt_module_symgelf32(sym, symp));
381 	}
382 
383 	return (NULL);
384 }
385 
386 static GElf_Sym *
387 dt_module_symaddr64(dt_module_t *dmp, GElf_Addr addr,
388     GElf_Sym *symp, uint_t *idp)
389 {
390 	const Elf64_Sym **asmap = (const Elf64_Sym **)dmp->dm_asmap;
391 	const Elf64_Sym *symtab = dmp->dm_symtab.cts_data;
392 	const Elf64_Sym *sym;
393 
394 	uint_t i, mid, lo = 0, hi = dmp->dm_aslen - 1;
395 	Elf64_Addr v;
396 
397 	if (dmp->dm_aslen == 0)
398 		return (NULL);
399 
400 	while (hi - lo > 1) {
401 		mid = (lo + hi) / 2;
402 		if (addr >= asmap[mid]->st_value)
403 			lo = mid;
404 		else
405 			hi = mid;
406 	}
407 
408 	i = addr < asmap[hi]->st_value ? lo : hi;
409 	sym = asmap[i];
410 	v = sym->st_value;
411 
412 	/*
413 	 * If the previous entry has the same value, improve our choice.  The
414 	 * order of equal-valued symbols is determined by the comparison func.
415 	 */
416 	while (i-- != 0 && asmap[i]->st_value == v)
417 		sym = asmap[i];
418 
419 	if (addr - sym->st_value < MAX(sym->st_size, 1)) {
420 		if (idp != NULL)
421 			*idp = (uint_t)(sym - symtab);
422 		return (dt_module_symgelf64(sym, symp));
423 	}
424 
425 	return (NULL);
426 }
427 
428 static const dt_modops_t dt_modops_32 = {
429 	dt_module_syminit32,
430 	dt_module_symsort32,
431 	dt_module_symname32,
432 	dt_module_symaddr32
433 };
434 
435 static const dt_modops_t dt_modops_64 = {
436 	dt_module_syminit64,
437 	dt_module_symsort64,
438 	dt_module_symname64,
439 	dt_module_symaddr64
440 };
441 
442 dt_module_t *
443 dt_module_create(dtrace_hdl_t *dtp, const char *name)
444 {
445 	uint_t h = dt_strtab_hash(name, NULL) % dtp->dt_modbuckets;
446 	dt_module_t *dmp;
447 
448 	for (dmp = dtp->dt_mods[h]; dmp != NULL; dmp = dmp->dm_next) {
449 		if (strcmp(dmp->dm_name, name) == 0)
450 			return (dmp);
451 	}
452 
453 	if ((dmp = malloc(sizeof (dt_module_t))) == NULL)
454 		return (NULL); /* caller must handle allocation failure */
455 
456 	bzero(dmp, sizeof (dt_module_t));
457 	(void) strlcpy(dmp->dm_name, name, sizeof (dmp->dm_name));
458 	dt_list_append(&dtp->dt_modlist, dmp);
459 	dmp->dm_next = dtp->dt_mods[h];
460 	dtp->dt_mods[h] = dmp;
461 	dtp->dt_nmods++;
462 
463 	if (dtp->dt_conf.dtc_ctfmodel == CTF_MODEL_LP64)
464 		dmp->dm_ops = &dt_modops_64;
465 	else
466 		dmp->dm_ops = &dt_modops_32;
467 
468 	return (dmp);
469 }
470 
471 dt_module_t *
472 dt_module_lookup_by_name(dtrace_hdl_t *dtp, const char *name)
473 {
474 	uint_t h = dt_strtab_hash(name, NULL) % dtp->dt_modbuckets;
475 	dt_module_t *dmp;
476 
477 	for (dmp = dtp->dt_mods[h]; dmp != NULL; dmp = dmp->dm_next) {
478 		if (strcmp(dmp->dm_name, name) == 0)
479 			return (dmp);
480 	}
481 
482 	return (NULL);
483 }
484 
485 /*ARGSUSED*/
486 dt_module_t *
487 dt_module_lookup_by_ctf(dtrace_hdl_t *dtp, ctf_file_t *ctfp)
488 {
489 	return (ctfp ? ctf_getspecific(ctfp) : NULL);
490 }
491 
492 static int
493 dt_module_load_sect(dtrace_hdl_t *dtp, dt_module_t *dmp, ctf_sect_t *ctsp)
494 {
495 	const char *s;
496 	size_t shstrs;
497 	GElf_Shdr sh;
498 	Elf_Data *dp;
499 	Elf_Scn *sp;
500 
501 	if (elf_getshstrndx(dmp->dm_elf, &shstrs) == 0)
502 		return (dt_set_errno(dtp, EDT_NOTLOADED));
503 
504 	for (sp = NULL; (sp = elf_nextscn(dmp->dm_elf, sp)) != NULL; ) {
505 		if (gelf_getshdr(sp, &sh) == NULL || sh.sh_type == SHT_NULL ||
506 		    (s = elf_strptr(dmp->dm_elf, shstrs, sh.sh_name)) == NULL)
507 			continue; /* skip any malformed sections */
508 
509 		if (sh.sh_type == ctsp->cts_type &&
510 		    sh.sh_entsize == ctsp->cts_entsize &&
511 		    strcmp(s, ctsp->cts_name) == 0)
512 			break; /* section matches specification */
513 	}
514 
515 	/*
516 	 * If the section isn't found, return success but leave cts_data set
517 	 * to NULL and cts_size set to zero for our caller.
518 	 */
519 	if (sp == NULL || (dp = elf_getdata(sp, NULL)) == NULL)
520 		return (0);
521 
522 #if defined(sun)
523 	ctsp->cts_data = dp->d_buf;
524 #else
525 	if ((ctsp->cts_data = malloc(dp->d_size)) == NULL)
526 		return (0);
527 	memcpy(ctsp->cts_data, dp->d_buf, dp->d_size);
528 #endif
529 	ctsp->cts_size = dp->d_size;
530 
531 	dt_dprintf("loaded %s [%s] (%lu bytes)\n",
532 	    dmp->dm_name, ctsp->cts_name, (ulong_t)ctsp->cts_size);
533 
534 	return (0);
535 }
536 
537 int
538 dt_module_load(dtrace_hdl_t *dtp, dt_module_t *dmp)
539 {
540 	if (dmp->dm_flags & DT_DM_LOADED)
541 		return (0); /* module is already loaded */
542 
543 	dmp->dm_ctdata.cts_name = ".SUNW_ctf";
544 	dmp->dm_ctdata.cts_type = SHT_PROGBITS;
545 	dmp->dm_ctdata.cts_flags = 0;
546 	dmp->dm_ctdata.cts_data = NULL;
547 	dmp->dm_ctdata.cts_size = 0;
548 	dmp->dm_ctdata.cts_entsize = 0;
549 	dmp->dm_ctdata.cts_offset = 0;
550 
551 	dmp->dm_symtab.cts_name = ".symtab";
552 	dmp->dm_symtab.cts_type = SHT_SYMTAB;
553 	dmp->dm_symtab.cts_flags = 0;
554 	dmp->dm_symtab.cts_data = NULL;
555 	dmp->dm_symtab.cts_size = 0;
556 	dmp->dm_symtab.cts_entsize = dmp->dm_ops == &dt_modops_64 ?
557 	    sizeof (Elf64_Sym) : sizeof (Elf32_Sym);
558 	dmp->dm_symtab.cts_offset = 0;
559 
560 	dmp->dm_strtab.cts_name = ".strtab";
561 	dmp->dm_strtab.cts_type = SHT_STRTAB;
562 	dmp->dm_strtab.cts_flags = 0;
563 	dmp->dm_strtab.cts_data = NULL;
564 	dmp->dm_strtab.cts_size = 0;
565 	dmp->dm_strtab.cts_entsize = 0;
566 	dmp->dm_strtab.cts_offset = 0;
567 
568 	/*
569 	 * Attempt to load the module's CTF section, symbol table section, and
570 	 * string table section.  Note that modules may not contain CTF data:
571 	 * this will result in a successful load_sect but data of size zero.
572 	 * We will then fail if dt_module_getctf() is called, as shown below.
573 	 */
574 	if (dt_module_load_sect(dtp, dmp, &dmp->dm_ctdata) == -1 ||
575 	    dt_module_load_sect(dtp, dmp, &dmp->dm_symtab) == -1 ||
576 	    dt_module_load_sect(dtp, dmp, &dmp->dm_strtab) == -1) {
577 		dt_module_unload(dtp, dmp);
578 		return (-1); /* dt_errno is set for us */
579 	}
580 
581 	/*
582 	 * Allocate the hash chains and hash buckets for symbol name lookup.
583 	 * This is relatively simple since the symbol table is of fixed size
584 	 * and is known in advance.  We allocate one extra element since we
585 	 * use element indices instead of pointers and zero is our sentinel.
586 	 */
587 	dmp->dm_nsymelems =
588 	    dmp->dm_symtab.cts_size / dmp->dm_symtab.cts_entsize;
589 
590 	dmp->dm_nsymbuckets = _dtrace_strbuckets;
591 	dmp->dm_symfree = 1;		/* first free element is index 1 */
592 
593 	dmp->dm_symbuckets = malloc(sizeof (uint_t) * dmp->dm_nsymbuckets);
594 	dmp->dm_symchains = malloc(sizeof (dt_sym_t) * dmp->dm_nsymelems + 1);
595 
596 	if (dmp->dm_symbuckets == NULL || dmp->dm_symchains == NULL) {
597 		dt_module_unload(dtp, dmp);
598 		return (dt_set_errno(dtp, EDT_NOMEM));
599 	}
600 
601 	bzero(dmp->dm_symbuckets, sizeof (uint_t) * dmp->dm_nsymbuckets);
602 	bzero(dmp->dm_symchains, sizeof (dt_sym_t) * dmp->dm_nsymelems + 1);
603 
604 	/*
605 	 * Iterate over the symbol table data buffer and insert each symbol
606 	 * name into the name hash if the name and type are valid.  Then
607 	 * allocate the address map, fill it in, and sort it.
608 	 */
609 	dmp->dm_asrsv = dmp->dm_ops->do_syminit(dmp);
610 
611 	dt_dprintf("hashed %s [%s] (%u symbols)\n",
612 	    dmp->dm_name, dmp->dm_symtab.cts_name, dmp->dm_symfree - 1);
613 
614 	if ((dmp->dm_asmap = malloc(sizeof (void *) * dmp->dm_asrsv)) == NULL) {
615 		dt_module_unload(dtp, dmp);
616 		return (dt_set_errno(dtp, EDT_NOMEM));
617 	}
618 
619 	dmp->dm_ops->do_symsort(dmp);
620 
621 	dt_dprintf("sorted %s [%s] (%u symbols)\n",
622 	    dmp->dm_name, dmp->dm_symtab.cts_name, dmp->dm_aslen);
623 
624 	dmp->dm_flags |= DT_DM_LOADED;
625 	return (0);
626 }
627 
628 ctf_file_t *
629 dt_module_getctf(dtrace_hdl_t *dtp, dt_module_t *dmp)
630 {
631 	const char *parent;
632 	dt_module_t *pmp;
633 	ctf_file_t *pfp;
634 	int model;
635 
636 	if (dmp->dm_ctfp != NULL || dt_module_load(dtp, dmp) != 0)
637 		return (dmp->dm_ctfp);
638 
639 	if (dmp->dm_ops == &dt_modops_64)
640 		model = CTF_MODEL_LP64;
641 	else
642 		model = CTF_MODEL_ILP32;
643 
644 	/*
645 	 * If the data model of the module does not match our program data
646 	 * model, then do not permit CTF from this module to be opened and
647 	 * returned to the compiler.  If we support mixed data models in the
648 	 * future for combined kernel/user tracing, this can be removed.
649 	 */
650 	if (dtp->dt_conf.dtc_ctfmodel != model) {
651 		(void) dt_set_errno(dtp, EDT_DATAMODEL);
652 		return (NULL);
653 	}
654 
655 	if (dmp->dm_ctdata.cts_size == 0) {
656 		(void) dt_set_errno(dtp, EDT_NOCTF);
657 		return (NULL);
658 	}
659 
660 	dmp->dm_ctfp = ctf_bufopen(&dmp->dm_ctdata,
661 	    &dmp->dm_symtab, &dmp->dm_strtab, &dtp->dt_ctferr);
662 
663 	if (dmp->dm_ctfp == NULL) {
664 		(void) dt_set_errno(dtp, EDT_CTF);
665 		return (NULL);
666 	}
667 
668 	(void) ctf_setmodel(dmp->dm_ctfp, model);
669 	ctf_setspecific(dmp->dm_ctfp, dmp);
670 
671 	if ((parent = ctf_parent_name(dmp->dm_ctfp)) != NULL) {
672 		if ((pmp = dt_module_create(dtp, parent)) == NULL ||
673 		    (pfp = dt_module_getctf(dtp, pmp)) == NULL) {
674 			if (pmp == NULL)
675 				(void) dt_set_errno(dtp, EDT_NOMEM);
676 			goto err;
677 		}
678 
679 		if (ctf_import(dmp->dm_ctfp, pfp) == CTF_ERR) {
680 			dtp->dt_ctferr = ctf_errno(dmp->dm_ctfp);
681 			(void) dt_set_errno(dtp, EDT_CTF);
682 			goto err;
683 		}
684 	}
685 
686 	dt_dprintf("loaded CTF container for %s (%p)\n",
687 	    dmp->dm_name, (void *)dmp->dm_ctfp);
688 
689 	return (dmp->dm_ctfp);
690 
691 err:
692 	ctf_close(dmp->dm_ctfp);
693 	dmp->dm_ctfp = NULL;
694 	return (NULL);
695 }
696 
697 /*ARGSUSED*/
698 void
699 dt_module_unload(dtrace_hdl_t *dtp, dt_module_t *dmp)
700 {
701 	ctf_close(dmp->dm_ctfp);
702 	dmp->dm_ctfp = NULL;
703 
704 #if !defined(sun)
705 	if (dmp->dm_ctdata.cts_data != NULL) {
706 		free(dmp->dm_ctdata.cts_data);
707 	}
708 	if (dmp->dm_symtab.cts_data != NULL) {
709 		free(dmp->dm_symtab.cts_data);
710 	}
711 	if (dmp->dm_strtab.cts_data != NULL) {
712 		free(dmp->dm_strtab.cts_data);
713 	}
714 #endif
715 
716 	bzero(&dmp->dm_ctdata, sizeof (ctf_sect_t));
717 	bzero(&dmp->dm_symtab, sizeof (ctf_sect_t));
718 	bzero(&dmp->dm_strtab, sizeof (ctf_sect_t));
719 
720 	if (dmp->dm_symbuckets != NULL) {
721 		free(dmp->dm_symbuckets);
722 		dmp->dm_symbuckets = NULL;
723 	}
724 
725 	if (dmp->dm_symchains != NULL) {
726 		free(dmp->dm_symchains);
727 		dmp->dm_symchains = NULL;
728 	}
729 
730 	if (dmp->dm_asmap != NULL) {
731 		free(dmp->dm_asmap);
732 		dmp->dm_asmap = NULL;
733 	}
734 
735 	dmp->dm_symfree = 0;
736 	dmp->dm_nsymbuckets = 0;
737 	dmp->dm_nsymelems = 0;
738 	dmp->dm_asrsv = 0;
739 	dmp->dm_aslen = 0;
740 
741 	dmp->dm_text_va = 0;
742 	dmp->dm_text_size = 0;
743 	dmp->dm_data_va = 0;
744 	dmp->dm_data_size = 0;
745 	dmp->dm_bss_va = 0;
746 	dmp->dm_bss_size = 0;
747 
748 	if (dmp->dm_extern != NULL) {
749 		dt_idhash_destroy(dmp->dm_extern);
750 		dmp->dm_extern = NULL;
751 	}
752 
753 	(void) elf_end(dmp->dm_elf);
754 	dmp->dm_elf = NULL;
755 
756 	dmp->dm_flags &= ~DT_DM_LOADED;
757 }
758 
759 void
760 dt_module_destroy(dtrace_hdl_t *dtp, dt_module_t *dmp)
761 {
762 	dt_list_delete(&dtp->dt_modlist, dmp);
763 	assert(dtp->dt_nmods != 0);
764 	dtp->dt_nmods--;
765 
766 	dt_module_unload(dtp, dmp);
767 	free(dmp);
768 }
769 
770 /*
771  * Insert a new external symbol reference into the specified module.  The new
772  * symbol will be marked as undefined and is assigned a symbol index beyond
773  * any existing cached symbols from this module.  We use the ident's di_data
774  * field to store a pointer to a copy of the dtrace_syminfo_t for this symbol.
775  */
776 dt_ident_t *
777 dt_module_extern(dtrace_hdl_t *dtp, dt_module_t *dmp,
778     const char *name, const dtrace_typeinfo_t *tip)
779 {
780 	dtrace_syminfo_t *sip;
781 	dt_ident_t *idp;
782 	uint_t id;
783 
784 	if (dmp->dm_extern == NULL && (dmp->dm_extern = dt_idhash_create(
785 	    "extern", NULL, dmp->dm_nsymelems, UINT_MAX)) == NULL) {
786 		(void) dt_set_errno(dtp, EDT_NOMEM);
787 		return (NULL);
788 	}
789 
790 	if (dt_idhash_nextid(dmp->dm_extern, &id) == -1) {
791 		(void) dt_set_errno(dtp, EDT_SYMOFLOW);
792 		return (NULL);
793 	}
794 
795 	if ((sip = malloc(sizeof (dtrace_syminfo_t))) == NULL) {
796 		(void) dt_set_errno(dtp, EDT_NOMEM);
797 		return (NULL);
798 	}
799 
800 	idp = dt_idhash_insert(dmp->dm_extern, name, DT_IDENT_SYMBOL, 0, id,
801 	    _dtrace_symattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen);
802 
803 	if (idp == NULL) {
804 		(void) dt_set_errno(dtp, EDT_NOMEM);
805 		free(sip);
806 		return (NULL);
807 	}
808 
809 	sip->dts_object = dmp->dm_name;
810 	sip->dts_name = idp->di_name;
811 	sip->dts_id = idp->di_id;
812 
813 	idp->di_data = sip;
814 	idp->di_ctfp = tip->dtt_ctfp;
815 	idp->di_type = tip->dtt_type;
816 
817 	return (idp);
818 }
819 
820 const char *
821 dt_module_modelname(dt_module_t *dmp)
822 {
823 	if (dmp->dm_ops == &dt_modops_64)
824 		return ("64-bit");
825 	else
826 		return ("32-bit");
827 }
828 
829 /*
830  * Update our module cache by adding an entry for the specified module 'name'.
831  * We create the dt_module_t and populate it using /system/object/<name>/.
832  *
833  * On FreeBSD, the module name is passed as the full module file name,
834  * including the path.
835  */
836 static void
837 dt_module_update(dtrace_hdl_t *dtp, const char *name)
838 {
839 	char fname[MAXPATHLEN];
840 	struct stat64 st;
841 	int fd, err, bits;
842 
843 	dt_module_t *dmp;
844 	const char *s;
845 	size_t shstrs;
846 	GElf_Shdr sh;
847 	Elf_Data *dp;
848 	Elf_Scn *sp;
849 
850 #if defined(sun)
851 	(void) snprintf(fname, sizeof (fname),
852 	    "%s/%s/object", OBJFS_ROOT, name);
853 #else
854 	GElf_Phdr ph;
855 	int i;
856 	int mib_osrel[2] = { CTL_KERN, KERN_OSRELEASE };
857 	int mib_mach[2] = { CTL_HW, HW_MACHINE };
858 	char osrel[64];
859 	char machine[64];
860 	size_t len;
861 
862 	printf("dt_module_update: %s\n", name);	/* XXX debug */
863 
864 	if (strcmp("netbsd",name) == 0) {
865 		/* want the kernel */
866 		strncpy(fname, "/netbsd", sizeof(fname));
867 	} else {
868 
869 		/* build stand module path from system */
870 		len = sizeof(osrel);
871 		if (sysctl(mib_osrel, 2, osrel, &len, NULL, 0) == -1) {
872 			dt_dprintf("sysctl osrel failed: %s\n",
873 				strerror(errno));
874 		    return;
875 		}
876 
877 		len = sizeof(machine);
878 		if (sysctl(mib_mach, 2, machine, &len, NULL, 0) == -1) {
879 			dt_dprintf("sysctl machine failed: %s\n",
880 				strerror(errno));
881 		    return;
882 		}
883 
884 		(void) snprintf(fname, sizeof (fname),
885 		    "/stand/%s/%s/%s.kmod", machine, osrel, name, name);
886 	}
887 #endif
888 
889 	if ((fd = open(fname, O_RDONLY)) == -1 || fstat64(fd, &st) == -1 ||
890 	    (dmp = dt_module_create(dtp, name)) == NULL) {
891 		dt_dprintf("failed to open %s: %s\n", fname, strerror(errno));
892 		(void) close(fd);
893 		return;
894 	}
895 
896 	/*
897 	 * Since the module can unload out from under us (and /system/object
898 	 * will return ENOENT), tell libelf to cook the entire file now and
899 	 * then close the underlying file descriptor immediately.  If this
900 	 * succeeds, we know that we can continue safely using dmp->dm_elf.
901 	 */
902 	dmp->dm_elf = elf_begin(fd, ELF_C_READ, NULL);
903 	err = elf_cntl(dmp->dm_elf, ELF_C_FDREAD);
904 	(void) close(fd);
905 
906 	if (dmp->dm_elf == NULL || err == -1 ||
907 	    elf_getshstrndx(dmp->dm_elf, &shstrs) == 0) {
908 		dt_dprintf("failed to load %s: %s\n",
909 		    fname, elf_errmsg(elf_errno()));
910 		dt_module_destroy(dtp, dmp);
911 		return;
912 	}
913 
914 	switch (gelf_getclass(dmp->dm_elf)) {
915 	case ELFCLASS32:
916 		dmp->dm_ops = &dt_modops_32;
917 		bits = 32;
918 		break;
919 	case ELFCLASS64:
920 		dmp->dm_ops = &dt_modops_64;
921 		bits = 64;
922 		break;
923 	default:
924 		dt_dprintf("failed to load %s: unknown ELF class\n", fname);
925 		dt_module_destroy(dtp, dmp);
926 		return;
927 	}
928 
929 	/*
930 	 * Iterate over the section headers locating various sections of
931 	 * interest and use their attributes to flesh out the dt_module_t.
932 	 */
933 	for (sp = NULL; (sp = elf_nextscn(dmp->dm_elf, sp)) != NULL; ) {
934 		if (gelf_getshdr(sp, &sh) == NULL || sh.sh_type == SHT_NULL ||
935 		    (s = elf_strptr(dmp->dm_elf, shstrs, sh.sh_name)) == NULL)
936 			continue; /* skip any malformed sections */
937 
938 		if (strcmp(s, ".text") == 0) {
939 			dmp->dm_text_size = sh.sh_size;
940 			dmp->dm_text_va = sh.sh_addr;
941 		} else if (strcmp(s, ".data") == 0) {
942 			dmp->dm_data_size = sh.sh_size;
943 			dmp->dm_data_va = sh.sh_addr;
944 		} else if (strcmp(s, ".bss") == 0) {
945 			dmp->dm_bss_size = sh.sh_size;
946 			dmp->dm_bss_va = sh.sh_addr;
947 		} else if (strcmp(s, ".info") == 0 &&
948 		    (dp = elf_getdata(sp, NULL)) != NULL) {
949 			bcopy(dp->d_buf, &dmp->dm_info,
950 			    MIN(sh.sh_size, sizeof (dmp->dm_info)));
951 		} else if (strcmp(s, ".filename") == 0 &&
952 		    (dp = elf_getdata(sp, NULL)) != NULL) {
953 			(void) strlcpy(dmp->dm_file,
954 			    dp->d_buf, sizeof (dmp->dm_file));
955 		}
956 	}
957 
958 	dmp->dm_flags |= DT_DM_KERNEL;
959 #if defined(sun)
960 	dmp->dm_modid = (int)OBJFS_MODID(st.st_ino);
961 #else
962 #if defined(__i386__)
963 #if 0	/* XXX TBD needs module support */
964 	/*
965 	 * Find the first load section and figure out the relocation
966 	 * offset for the symbols. The kernel module will not need
967 	 * relocation, but the kernel linker modules will.
968 	 */
969 	for (i = 0; gelf_getphdr(dmp->dm_elf, i, &ph) != NULL; i++) {
970 		if (ph.p_type == PT_LOAD) {
971 			dmp->dm_reloc_offset = k_stat->address - ph.p_vaddr;
972 			break;
973 		}
974 	}
975 #endif
976 #endif
977 #endif
978 
979 	if (dmp->dm_info.objfs_info_primary)
980 		dmp->dm_flags |= DT_DM_PRIMARY;
981 
982 	dt_dprintf("opened %d-bit module %s (%s) [%d]\n",
983 	    bits, dmp->dm_name, dmp->dm_file, dmp->dm_modid);
984 }
985 
986 /*
987  * Unload all the loaded modules and then refresh the module cache with the
988  * latest list of loaded modules and their address ranges.
989  */
990 void
991 dtrace_update(dtrace_hdl_t *dtp)
992 {
993 	dt_module_t *dmp;
994 	DIR *dirp;
995 #if defined(__FreeBSD__)
996 	int fileid;
997 #endif
998 
999 	for (dmp = dt_list_next(&dtp->dt_modlist);
1000 	    dmp != NULL; dmp = dt_list_next(dmp))
1001 		dt_module_unload(dtp, dmp);
1002 
1003 #if defined(sun)
1004 	/*
1005 	 * Open /system/object and attempt to create a libdtrace module for
1006 	 * each kernel module that is loaded on the current system.
1007 	 */
1008 	if (!(dtp->dt_oflags & DTRACE_O_NOSYS) &&
1009 	    (dirp = opendir(OBJFS_ROOT)) != NULL) {
1010 		struct dirent *dp;
1011 
1012 		while ((dp = readdir(dirp)) != NULL) {
1013 			if (dp->d_name[0] != '.')
1014 				dt_module_update(dtp, dp->d_name);
1015 		}
1016 
1017 		(void) closedir(dirp);
1018 	}
1019 #elif defined(__FreeBSD__)
1020 	/*
1021 	 * Use FreeBSD's kernel loader interface to discover what kernel
1022 	 * modules are loaded and create a libdtrace module for each one.
1023 	 */
1024 	for (fileid = kldnext(0); fileid > 0; fileid = kldnext(fileid)) {
1025 		struct kld_file_stat k_stat;
1026 		k_stat.version = sizeof(k_stat);
1027 		if (kldstat(fileid, &k_stat) == 0)
1028 			dt_module_update(dtp, &k_stat);
1029 	}
1030 #else
1031 	/* XXX just the kernel for now */
1032 	dt_module_update(dtp, "netbsd");
1033 #endif
1034 
1035 	/*
1036 	 * Look up all the macro identifiers and set di_id to the latest value.
1037 	 * This code collaborates with dt_lex.l on the use of di_id.  We will
1038 	 * need to implement something fancier if we need to support non-ints.
1039 	 */
1040 	dt_idhash_lookup(dtp->dt_macros, "egid")->di_id = getegid();
1041 	dt_idhash_lookup(dtp->dt_macros, "euid")->di_id = geteuid();
1042 	dt_idhash_lookup(dtp->dt_macros, "gid")->di_id = getgid();
1043 	dt_idhash_lookup(dtp->dt_macros, "pid")->di_id = getpid();
1044 	dt_idhash_lookup(dtp->dt_macros, "pgid")->di_id = getpgid(0);
1045 	dt_idhash_lookup(dtp->dt_macros, "ppid")->di_id = getppid();
1046 #if defined(sun)
1047 	dt_idhash_lookup(dtp->dt_macros, "projid")->di_id = getprojid();
1048 #endif
1049 	dt_idhash_lookup(dtp->dt_macros, "sid")->di_id = getsid(0);
1050 #if defined(sun)
1051 	dt_idhash_lookup(dtp->dt_macros, "taskid")->di_id = gettaskid();
1052 #endif
1053 	dt_idhash_lookup(dtp->dt_macros, "uid")->di_id = getuid();
1054 
1055 	/*
1056 	 * Cache the pointers to the modules representing the base executable
1057 	 * and the run-time linker in the dtrace client handle. Note that on
1058 	 * x86 krtld is folded into unix, so if we don't find it, use unix
1059 	 * instead.
1060 	 */
1061 	dtp->dt_exec = dt_module_lookup_by_name(dtp, "genunix");
1062 	dtp->dt_rtld = dt_module_lookup_by_name(dtp, "krtld");
1063 	if (dtp->dt_rtld == NULL)
1064 		dtp->dt_rtld = dt_module_lookup_by_name(dtp, "unix");
1065 
1066 	/*
1067 	 * If this is the first time we are initializing the module list,
1068 	 * remove the module for genunix from the module list and then move it
1069 	 * to the front of the module list.  We do this so that type and symbol
1070 	 * queries encounter genunix and thereby optimize for the common case
1071 	 * in dtrace_lookup_by_name() and dtrace_lookup_by_type(), below.
1072 	 */
1073 	if (dtp->dt_exec != NULL &&
1074 	    dtp->dt_cdefs == NULL && dtp->dt_ddefs == NULL) {
1075 		dt_list_delete(&dtp->dt_modlist, dtp->dt_exec);
1076 		dt_list_prepend(&dtp->dt_modlist, dtp->dt_exec);
1077 	}
1078 }
1079 
1080 static dt_module_t *
1081 dt_module_from_object(dtrace_hdl_t *dtp, const char *object)
1082 {
1083 	int err = EDT_NOMOD;
1084 	dt_module_t *dmp;
1085 
1086 	switch ((uintptr_t)object) {
1087 	case (uintptr_t)DTRACE_OBJ_EXEC:
1088 		dmp = dtp->dt_exec;
1089 		break;
1090 	case (uintptr_t)DTRACE_OBJ_RTLD:
1091 		dmp = dtp->dt_rtld;
1092 		break;
1093 	case (uintptr_t)DTRACE_OBJ_CDEFS:
1094 		dmp = dtp->dt_cdefs;
1095 		break;
1096 	case (uintptr_t)DTRACE_OBJ_DDEFS:
1097 		dmp = dtp->dt_ddefs;
1098 		break;
1099 	default:
1100 		dmp = dt_module_create(dtp, object);
1101 		err = EDT_NOMEM;
1102 	}
1103 
1104 	if (dmp == NULL)
1105 		(void) dt_set_errno(dtp, err);
1106 
1107 	return (dmp);
1108 }
1109 
1110 /*
1111  * Exported interface to look up a symbol by name.  We return the GElf_Sym and
1112  * complete symbol information for the matching symbol.
1113  */
1114 int
1115 dtrace_lookup_by_name(dtrace_hdl_t *dtp, const char *object, const char *name,
1116     GElf_Sym *symp, dtrace_syminfo_t *sip)
1117 {
1118 	dt_module_t *dmp;
1119 	dt_ident_t *idp;
1120 	uint_t n, id;
1121 	GElf_Sym sym;
1122 
1123 	uint_t mask = 0; /* mask of dt_module flags to match */
1124 	uint_t bits = 0; /* flag bits that must be present */
1125 
1126 	if (object != DTRACE_OBJ_EVERY &&
1127 	    object != DTRACE_OBJ_KMODS &&
1128 	    object != DTRACE_OBJ_UMODS) {
1129 		if ((dmp = dt_module_from_object(dtp, object)) == NULL)
1130 			return (-1); /* dt_errno is set for us */
1131 
1132 		if (dt_module_load(dtp, dmp) == -1)
1133 			return (-1); /* dt_errno is set for us */
1134 		n = 1;
1135 
1136 	} else {
1137 		if (object == DTRACE_OBJ_KMODS)
1138 			mask = bits = DT_DM_KERNEL;
1139 		else if (object == DTRACE_OBJ_UMODS)
1140 			mask = DT_DM_KERNEL;
1141 
1142 		dmp = dt_list_next(&dtp->dt_modlist);
1143 		n = dtp->dt_nmods;
1144 	}
1145 
1146 	if (symp == NULL)
1147 		symp = &sym;
1148 
1149 	for (; n > 0; n--, dmp = dt_list_next(dmp)) {
1150 		if ((dmp->dm_flags & mask) != bits)
1151 			continue; /* failed to match required attributes */
1152 
1153 		if (dt_module_load(dtp, dmp) == -1)
1154 			continue; /* failed to load symbol table */
1155 
1156 		if (dmp->dm_ops->do_symname(dmp, name, symp, &id) != NULL) {
1157 			if (sip != NULL) {
1158 				sip->dts_object = dmp->dm_name;
1159 				sip->dts_name = (const char *)
1160 				    dmp->dm_strtab.cts_data + symp->st_name;
1161 				sip->dts_id = id;
1162 			}
1163 			return (0);
1164 		}
1165 
1166 		if (dmp->dm_extern != NULL &&
1167 		    (idp = dt_idhash_lookup(dmp->dm_extern, name)) != NULL) {
1168 			if (symp != &sym) {
1169 				symp->st_name = (uintptr_t)idp->di_name;
1170 				symp->st_info =
1171 				    GELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
1172 				symp->st_other = 0;
1173 				symp->st_shndx = SHN_UNDEF;
1174 				symp->st_value = 0;
1175 				symp->st_size =
1176 				    ctf_type_size(idp->di_ctfp, idp->di_type);
1177 			}
1178 
1179 			if (sip != NULL) {
1180 				sip->dts_object = dmp->dm_name;
1181 				sip->dts_name = idp->di_name;
1182 				sip->dts_id = idp->di_id;
1183 			}
1184 
1185 			return (0);
1186 		}
1187 	}
1188 
1189 	return (dt_set_errno(dtp, EDT_NOSYM));
1190 }
1191 
1192 /*
1193  * Exported interface to look up a symbol by address.  We return the GElf_Sym
1194  * and complete symbol information for the matching symbol.
1195  */
1196 int
1197 dtrace_lookup_by_addr(dtrace_hdl_t *dtp, GElf_Addr addr,
1198     GElf_Sym *symp, dtrace_syminfo_t *sip)
1199 {
1200 	dt_module_t *dmp;
1201 	uint_t id;
1202 	const dtrace_vector_t *v = dtp->dt_vector;
1203 
1204 	if (v != NULL)
1205 		return (v->dtv_lookup_by_addr(dtp->dt_varg, addr, symp, sip));
1206 
1207 	for (dmp = dt_list_next(&dtp->dt_modlist); dmp != NULL;
1208 	    dmp = dt_list_next(dmp)) {
1209 		if (addr - dmp->dm_text_va < dmp->dm_text_size ||
1210 		    addr - dmp->dm_data_va < dmp->dm_data_size ||
1211 		    addr - dmp->dm_bss_va < dmp->dm_bss_size)
1212 			break;
1213 	}
1214 
1215 	if (dmp == NULL)
1216 		return (dt_set_errno(dtp, EDT_NOSYMADDR));
1217 
1218 	if (dt_module_load(dtp, dmp) == -1)
1219 		return (-1); /* dt_errno is set for us */
1220 
1221 	if (symp != NULL) {
1222 		if (dmp->dm_ops->do_symaddr(dmp, addr, symp, &id) == NULL)
1223 			return (dt_set_errno(dtp, EDT_NOSYMADDR));
1224 	}
1225 
1226 	if (sip != NULL) {
1227 		sip->dts_object = dmp->dm_name;
1228 
1229 		if (symp != NULL) {
1230 			sip->dts_name = (const char *)
1231 			    dmp->dm_strtab.cts_data + symp->st_name;
1232 			sip->dts_id = id;
1233 		} else {
1234 			sip->dts_name = NULL;
1235 			sip->dts_id = 0;
1236 		}
1237 	}
1238 
1239 	return (0);
1240 }
1241 
1242 int
1243 dtrace_lookup_by_type(dtrace_hdl_t *dtp, const char *object, const char *name,
1244     dtrace_typeinfo_t *tip)
1245 {
1246 	dtrace_typeinfo_t ti;
1247 	dt_module_t *dmp;
1248 	int found = 0;
1249 	ctf_id_t id;
1250 	uint_t n;
1251 	int justone;
1252 
1253 	uint_t mask = 0; /* mask of dt_module flags to match */
1254 	uint_t bits = 0; /* flag bits that must be present */
1255 
1256 	if (object != DTRACE_OBJ_EVERY &&
1257 	    object != DTRACE_OBJ_KMODS &&
1258 	    object != DTRACE_OBJ_UMODS) {
1259 		if ((dmp = dt_module_from_object(dtp, object)) == NULL)
1260 			return (-1); /* dt_errno is set for us */
1261 
1262 		if (dt_module_load(dtp, dmp) == -1)
1263 			return (-1); /* dt_errno is set for us */
1264 		n = 1;
1265 		justone = 1;
1266 
1267 	} else {
1268 		if (object == DTRACE_OBJ_KMODS)
1269 			mask = bits = DT_DM_KERNEL;
1270 		else if (object == DTRACE_OBJ_UMODS)
1271 			mask = DT_DM_KERNEL;
1272 
1273 		dmp = dt_list_next(&dtp->dt_modlist);
1274 		n = dtp->dt_nmods;
1275 		justone = 0;
1276 	}
1277 
1278 	if (tip == NULL)
1279 		tip = &ti;
1280 
1281 	for (; n > 0; n--, dmp = dt_list_next(dmp)) {
1282 		if ((dmp->dm_flags & mask) != bits)
1283 			continue; /* failed to match required attributes */
1284 
1285 		/*
1286 		 * If we can't load the CTF container, continue on to the next
1287 		 * module.  If our search was scoped to only one module then
1288 		 * return immediately leaving dt_errno unmodified.
1289 		 */
1290 		if (dt_module_getctf(dtp, dmp) == NULL) {
1291 			if (justone)
1292 				return (-1);
1293 			continue;
1294 		}
1295 
1296 		/*
1297 		 * Look up the type in the module's CTF container.  If our
1298 		 * match is a forward declaration tag, save this choice in
1299 		 * 'tip' and keep going in the hope that we will locate the
1300 		 * underlying structure definition.  Otherwise just return.
1301 		 */
1302 		if ((id = ctf_lookup_by_name(dmp->dm_ctfp, name)) != CTF_ERR) {
1303 			tip->dtt_object = dmp->dm_name;
1304 			tip->dtt_ctfp = dmp->dm_ctfp;
1305 			tip->dtt_type = id;
1306 
1307 			if (ctf_type_kind(dmp->dm_ctfp, ctf_type_resolve(
1308 			    dmp->dm_ctfp, id)) != CTF_K_FORWARD)
1309 				return (0);
1310 
1311 			found++;
1312 		}
1313 	}
1314 
1315 	if (found == 0)
1316 		return (dt_set_errno(dtp, EDT_NOTYPE));
1317 
1318 	return (0);
1319 }
1320 
1321 int
1322 dtrace_symbol_type(dtrace_hdl_t *dtp, const GElf_Sym *symp,
1323     const dtrace_syminfo_t *sip, dtrace_typeinfo_t *tip)
1324 {
1325 	dt_module_t *dmp;
1326 
1327 	tip->dtt_object = NULL;
1328 	tip->dtt_ctfp = NULL;
1329 	tip->dtt_type = CTF_ERR;
1330 
1331 	if ((dmp = dt_module_lookup_by_name(dtp, sip->dts_object)) == NULL)
1332 		return (dt_set_errno(dtp, EDT_NOMOD));
1333 
1334 	if (symp->st_shndx == SHN_UNDEF && dmp->dm_extern != NULL) {
1335 		dt_ident_t *idp =
1336 		    dt_idhash_lookup(dmp->dm_extern, sip->dts_name);
1337 
1338 		if (idp == NULL)
1339 			return (dt_set_errno(dtp, EDT_NOSYM));
1340 
1341 		tip->dtt_ctfp = idp->di_ctfp;
1342 		tip->dtt_type = idp->di_type;
1343 
1344 	} else if (GELF_ST_TYPE(symp->st_info) != STT_FUNC) {
1345 		if (dt_module_getctf(dtp, dmp) == NULL)
1346 			return (-1); /* errno is set for us */
1347 
1348 		tip->dtt_ctfp = dmp->dm_ctfp;
1349 		tip->dtt_type = ctf_lookup_by_symbol(dmp->dm_ctfp, sip->dts_id);
1350 
1351 		if (tip->dtt_type == CTF_ERR) {
1352 			dtp->dt_ctferr = ctf_errno(tip->dtt_ctfp);
1353 			return (dt_set_errno(dtp, EDT_CTF));
1354 		}
1355 
1356 	} else {
1357 		tip->dtt_ctfp = DT_FPTR_CTFP(dtp);
1358 		tip->dtt_type = DT_FPTR_TYPE(dtp);
1359 	}
1360 
1361 	tip->dtt_object = dmp->dm_name;
1362 	return (0);
1363 }
1364 
1365 static dtrace_objinfo_t *
1366 dt_module_info(const dt_module_t *dmp, dtrace_objinfo_t *dto)
1367 {
1368 	dto->dto_name = dmp->dm_name;
1369 	dto->dto_file = dmp->dm_file;
1370 	dto->dto_id = dmp->dm_modid;
1371 	dto->dto_flags = 0;
1372 
1373 	if (dmp->dm_flags & DT_DM_KERNEL)
1374 		dto->dto_flags |= DTRACE_OBJ_F_KERNEL;
1375 	if (dmp->dm_flags & DT_DM_PRIMARY)
1376 		dto->dto_flags |= DTRACE_OBJ_F_PRIMARY;
1377 
1378 	dto->dto_text_va = dmp->dm_text_va;
1379 	dto->dto_text_size = dmp->dm_text_size;
1380 	dto->dto_data_va = dmp->dm_data_va;
1381 	dto->dto_data_size = dmp->dm_data_size;
1382 	dto->dto_bss_va = dmp->dm_bss_va;
1383 	dto->dto_bss_size = dmp->dm_bss_size;
1384 
1385 	return (dto);
1386 }
1387 
1388 int
1389 dtrace_object_iter(dtrace_hdl_t *dtp, dtrace_obj_f *func, void *data)
1390 {
1391 	const dt_module_t *dmp = dt_list_next(&dtp->dt_modlist);
1392 	dtrace_objinfo_t dto;
1393 	int rv;
1394 
1395 	for (; dmp != NULL; dmp = dt_list_next(dmp)) {
1396 		if ((rv = (*func)(dtp, dt_module_info(dmp, &dto), data)) != 0)
1397 			return (rv);
1398 	}
1399 
1400 	return (0);
1401 }
1402 
1403 int
1404 dtrace_object_info(dtrace_hdl_t *dtp, const char *object, dtrace_objinfo_t *dto)
1405 {
1406 	dt_module_t *dmp;
1407 
1408 	if (object == DTRACE_OBJ_EVERY || object == DTRACE_OBJ_KMODS ||
1409 	    object == DTRACE_OBJ_UMODS || dto == NULL)
1410 		return (dt_set_errno(dtp, EINVAL));
1411 
1412 	if ((dmp = dt_module_from_object(dtp, object)) == NULL)
1413 		return (-1); /* dt_errno is set for us */
1414 
1415 	if (dt_module_load(dtp, dmp) == -1)
1416 		return (-1); /* dt_errno is set for us */
1417 
1418 	(void) dt_module_info(dmp, dto);
1419 	return (0);
1420 }
1421