xref: /freebsd/cddl/contrib/opensolaris/lib/libdtrace/common/dt_module.c (revision 7661de35d15f582ab33e3bd6b8d909601557e436)
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 /*
23  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 #include <sys/types.h>
27 #if defined(sun)
28 #include <sys/modctl.h>
29 #include <sys/kobj.h>
30 #include <sys/kobj_impl.h>
31 #include <sys/sysmacros.h>
32 #include <sys/elf.h>
33 #include <sys/task.h>
34 #else
35 #include <sys/param.h>
36 #include <sys/linker.h>
37 #include <sys/stat.h>
38 #endif
39 
40 #include <unistd.h>
41 #if defined(sun)
42 #include <project.h>
43 #endif
44 #include <strings.h>
45 #include <stdlib.h>
46 #include <libelf.h>
47 #include <limits.h>
48 #include <assert.h>
49 #include <errno.h>
50 #include <dirent.h>
51 #if !defined(sun)
52 #include <fcntl.h>
53 #endif
54 
55 #include <dt_strtab.h>
56 #include <dt_module.h>
57 #include <dt_impl.h>
58 
59 static const char *dt_module_strtab; /* active strtab for qsort callbacks */
60 
61 static void
62 dt_module_symhash_insert(dt_module_t *dmp, const char *name, uint_t id)
63 {
64 	dt_sym_t *dsp = &dmp->dm_symchains[dmp->dm_symfree];
65 	uint_t h;
66 
67 	assert(dmp->dm_symfree < dmp->dm_nsymelems + 1);
68 
69 	dsp->ds_symid = id;
70 	h = dt_strtab_hash(name, NULL) % dmp->dm_nsymbuckets;
71 	dsp->ds_next = dmp->dm_symbuckets[h];
72 	dmp->dm_symbuckets[h] = dmp->dm_symfree++;
73 }
74 
75 static uint_t
76 dt_module_syminit32(dt_module_t *dmp)
77 {
78 #if STT_NUM != (STT_TLS + 1)
79 #error "STT_NUM has grown. update dt_module_syminit32()"
80 #endif
81 
82 	Elf32_Sym *sym = dmp->dm_symtab.cts_data;
83 	const char *base = dmp->dm_strtab.cts_data;
84 	size_t ss_size = dmp->dm_strtab.cts_size;
85 	uint_t i, n = dmp->dm_nsymelems;
86 	uint_t asrsv = 0;
87 
88 #if defined(__FreeBSD__)
89 	GElf_Ehdr ehdr;
90 	int is_elf_obj;
91 
92 	gelf_getehdr(dmp->dm_elf, &ehdr);
93 	is_elf_obj = (ehdr.e_type == ET_REL);
94 #endif
95 
96 	for (i = 0; i < n; i++, sym++) {
97 		const char *name = base + sym->st_name;
98 		uchar_t type = ELF32_ST_TYPE(sym->st_info);
99 
100 		if (type >= STT_NUM || type == STT_SECTION)
101 			continue; /* skip sections and unknown types */
102 
103 		if (sym->st_name == 0 || sym->st_name >= ss_size)
104 			continue; /* skip null or invalid names */
105 
106 		if (sym->st_value != 0 &&
107 		    (ELF32_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size)) {
108 			asrsv++; /* reserve space in the address map */
109 
110 #if defined(__FreeBSD__)
111 			sym->st_value += (Elf_Addr) dmp->dm_reloc_offset;
112 			if (is_elf_obj && sym->st_shndx != SHN_UNDEF &&
113 			    sym->st_shndx < ehdr.e_shnum)
114 				sym->st_value +=
115 				    dmp->dm_sec_offsets[sym->st_shndx];
116 #endif
117 		}
118 
119 		dt_module_symhash_insert(dmp, name, i);
120 	}
121 
122 	return (asrsv);
123 }
124 
125 static uint_t
126 dt_module_syminit64(dt_module_t *dmp)
127 {
128 #if STT_NUM != (STT_TLS + 1)
129 #error "STT_NUM has grown. update dt_module_syminit64()"
130 #endif
131 
132 	Elf64_Sym *sym = dmp->dm_symtab.cts_data;
133 	const char *base = dmp->dm_strtab.cts_data;
134 	size_t ss_size = dmp->dm_strtab.cts_size;
135 	uint_t i, n = dmp->dm_nsymelems;
136 	uint_t asrsv = 0;
137 
138 #if defined(__FreeBSD__)
139 	GElf_Ehdr ehdr;
140 	int is_elf_obj;
141 
142 	gelf_getehdr(dmp->dm_elf, &ehdr);
143 	is_elf_obj = (ehdr.e_type == ET_REL);
144 #endif
145 
146 	for (i = 0; i < n; i++, sym++) {
147 		const char *name = base + sym->st_name;
148 		uchar_t type = ELF64_ST_TYPE(sym->st_info);
149 
150 		if (type >= STT_NUM || type == STT_SECTION)
151 			continue; /* skip sections and unknown types */
152 
153 		if (sym->st_name == 0 || sym->st_name >= ss_size)
154 			continue; /* skip null or invalid names */
155 
156 		if (sym->st_value != 0 &&
157 		    (ELF64_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size)) {
158 			asrsv++; /* reserve space in the address map */
159 #if defined(__FreeBSD__)
160 			sym->st_value += (Elf_Addr) dmp->dm_reloc_offset;
161 			if (is_elf_obj && sym->st_shndx != SHN_UNDEF &&
162 			    sym->st_shndx < ehdr.e_shnum)
163 				sym->st_value +=
164 				    dmp->dm_sec_offsets[sym->st_shndx];
165 #endif
166 		}
167 
168 		dt_module_symhash_insert(dmp, name, i);
169 	}
170 
171 	return (asrsv);
172 }
173 
174 /*
175  * Sort comparison function for 32-bit symbol address-to-name lookups.  We sort
176  * symbols by value.  If values are equal, we prefer the symbol that is
177  * non-zero sized, typed, not weak, or lexically first, in that order.
178  */
179 static int
180 dt_module_symcomp32(const void *lp, const void *rp)
181 {
182 	Elf32_Sym *lhs = *((Elf32_Sym **)lp);
183 	Elf32_Sym *rhs = *((Elf32_Sym **)rp);
184 
185 	if (lhs->st_value != rhs->st_value)
186 		return (lhs->st_value > rhs->st_value ? 1 : -1);
187 
188 	if ((lhs->st_size == 0) != (rhs->st_size == 0))
189 		return (lhs->st_size == 0 ? 1 : -1);
190 
191 	if ((ELF32_ST_TYPE(lhs->st_info) == STT_NOTYPE) !=
192 	    (ELF32_ST_TYPE(rhs->st_info) == STT_NOTYPE))
193 		return (ELF32_ST_TYPE(lhs->st_info) == STT_NOTYPE ? 1 : -1);
194 
195 	if ((ELF32_ST_BIND(lhs->st_info) == STB_WEAK) !=
196 	    (ELF32_ST_BIND(rhs->st_info) == STB_WEAK))
197 		return (ELF32_ST_BIND(lhs->st_info) == STB_WEAK ? 1 : -1);
198 
199 	return (strcmp(dt_module_strtab + lhs->st_name,
200 	    dt_module_strtab + rhs->st_name));
201 }
202 
203 /*
204  * Sort comparison function for 64-bit symbol address-to-name lookups.  We sort
205  * symbols by value.  If values are equal, we prefer the symbol that is
206  * non-zero sized, typed, not weak, or lexically first, in that order.
207  */
208 static int
209 dt_module_symcomp64(const void *lp, const void *rp)
210 {
211 	Elf64_Sym *lhs = *((Elf64_Sym **)lp);
212 	Elf64_Sym *rhs = *((Elf64_Sym **)rp);
213 
214 	if (lhs->st_value != rhs->st_value)
215 		return (lhs->st_value > rhs->st_value ? 1 : -1);
216 
217 	if ((lhs->st_size == 0) != (rhs->st_size == 0))
218 		return (lhs->st_size == 0 ? 1 : -1);
219 
220 	if ((ELF64_ST_TYPE(lhs->st_info) == STT_NOTYPE) !=
221 	    (ELF64_ST_TYPE(rhs->st_info) == STT_NOTYPE))
222 		return (ELF64_ST_TYPE(lhs->st_info) == STT_NOTYPE ? 1 : -1);
223 
224 	if ((ELF64_ST_BIND(lhs->st_info) == STB_WEAK) !=
225 	    (ELF64_ST_BIND(rhs->st_info) == STB_WEAK))
226 		return (ELF64_ST_BIND(lhs->st_info) == STB_WEAK ? 1 : -1);
227 
228 	return (strcmp(dt_module_strtab + lhs->st_name,
229 	    dt_module_strtab + rhs->st_name));
230 }
231 
232 static void
233 dt_module_symsort32(dt_module_t *dmp)
234 {
235 	Elf32_Sym *symtab = (Elf32_Sym *)dmp->dm_symtab.cts_data;
236 	Elf32_Sym **sympp = (Elf32_Sym **)dmp->dm_asmap;
237 	const dt_sym_t *dsp = dmp->dm_symchains + 1;
238 	uint_t i, n = dmp->dm_symfree;
239 
240 	for (i = 1; i < n; i++, dsp++) {
241 		Elf32_Sym *sym = symtab + dsp->ds_symid;
242 		if (sym->st_value != 0 &&
243 		    (ELF32_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size))
244 			*sympp++ = sym;
245 	}
246 
247 	dmp->dm_aslen = (uint_t)(sympp - (Elf32_Sym **)dmp->dm_asmap);
248 	assert(dmp->dm_aslen <= dmp->dm_asrsv);
249 
250 	dt_module_strtab = dmp->dm_strtab.cts_data;
251 	qsort(dmp->dm_asmap, dmp->dm_aslen,
252 	    sizeof (Elf32_Sym *), dt_module_symcomp32);
253 	dt_module_strtab = NULL;
254 }
255 
256 static void
257 dt_module_symsort64(dt_module_t *dmp)
258 {
259 	Elf64_Sym *symtab = (Elf64_Sym *)dmp->dm_symtab.cts_data;
260 	Elf64_Sym **sympp = (Elf64_Sym **)dmp->dm_asmap;
261 	const dt_sym_t *dsp = dmp->dm_symchains + 1;
262 	uint_t i, n = dmp->dm_symfree;
263 
264 	for (i = 1; i < n; i++, dsp++) {
265 		Elf64_Sym *sym = symtab + dsp->ds_symid;
266 		if (sym->st_value != 0 &&
267 		    (ELF64_ST_BIND(sym->st_info) != STB_LOCAL || sym->st_size))
268 			*sympp++ = sym;
269 	}
270 
271 	dmp->dm_aslen = (uint_t)(sympp - (Elf64_Sym **)dmp->dm_asmap);
272 	assert(dmp->dm_aslen <= dmp->dm_asrsv);
273 
274 	dt_module_strtab = dmp->dm_strtab.cts_data;
275 	qsort(dmp->dm_asmap, dmp->dm_aslen,
276 	    sizeof (Elf64_Sym *), dt_module_symcomp64);
277 	dt_module_strtab = NULL;
278 }
279 
280 static GElf_Sym *
281 dt_module_symgelf32(const Elf32_Sym *src, GElf_Sym *dst)
282 {
283 	if (dst != NULL) {
284 		dst->st_name = src->st_name;
285 		dst->st_info = src->st_info;
286 		dst->st_other = src->st_other;
287 		dst->st_shndx = src->st_shndx;
288 		dst->st_value = src->st_value;
289 		dst->st_size = src->st_size;
290 	}
291 
292 	return (dst);
293 }
294 
295 static GElf_Sym *
296 dt_module_symgelf64(const Elf64_Sym *src, GElf_Sym *dst)
297 {
298 	if (dst != NULL)
299 		bcopy(src, dst, sizeof (GElf_Sym));
300 
301 	return (dst);
302 }
303 
304 static GElf_Sym *
305 dt_module_symname32(dt_module_t *dmp, const char *name,
306     GElf_Sym *symp, uint_t *idp)
307 {
308 	const Elf32_Sym *symtab = dmp->dm_symtab.cts_data;
309 	const char *strtab = dmp->dm_strtab.cts_data;
310 
311 	const Elf32_Sym *sym;
312 	const dt_sym_t *dsp;
313 	uint_t i, h;
314 
315 	if (dmp->dm_nsymelems == 0)
316 		return (NULL);
317 
318 	h = dt_strtab_hash(name, NULL) % dmp->dm_nsymbuckets;
319 
320 	for (i = dmp->dm_symbuckets[h]; i != 0; i = dsp->ds_next) {
321 		dsp = &dmp->dm_symchains[i];
322 		sym = symtab + dsp->ds_symid;
323 
324 		if (strcmp(name, strtab + sym->st_name) == 0) {
325 			if (idp != NULL)
326 				*idp = dsp->ds_symid;
327 			return (dt_module_symgelf32(sym, symp));
328 		}
329 	}
330 
331 	return (NULL);
332 }
333 
334 static GElf_Sym *
335 dt_module_symname64(dt_module_t *dmp, const char *name,
336     GElf_Sym *symp, uint_t *idp)
337 {
338 	const Elf64_Sym *symtab = dmp->dm_symtab.cts_data;
339 	const char *strtab = dmp->dm_strtab.cts_data;
340 
341 	const Elf64_Sym *sym;
342 	const dt_sym_t *dsp;
343 	uint_t i, h;
344 
345 	if (dmp->dm_nsymelems == 0)
346 		return (NULL);
347 
348 	h = dt_strtab_hash(name, NULL) % dmp->dm_nsymbuckets;
349 
350 	for (i = dmp->dm_symbuckets[h]; i != 0; i = dsp->ds_next) {
351 		dsp = &dmp->dm_symchains[i];
352 		sym = symtab + dsp->ds_symid;
353 
354 		if (strcmp(name, strtab + sym->st_name) == 0) {
355 			if (idp != NULL)
356 				*idp = dsp->ds_symid;
357 			return (dt_module_symgelf64(sym, symp));
358 		}
359 	}
360 
361 	return (NULL);
362 }
363 
364 static GElf_Sym *
365 dt_module_symaddr32(dt_module_t *dmp, GElf_Addr addr,
366     GElf_Sym *symp, uint_t *idp)
367 {
368 	const Elf32_Sym **asmap = (const Elf32_Sym **)dmp->dm_asmap;
369 	const Elf32_Sym *symtab = dmp->dm_symtab.cts_data;
370 	const Elf32_Sym *sym;
371 
372 	uint_t i, mid, lo = 0, hi = dmp->dm_aslen - 1;
373 	Elf32_Addr v;
374 
375 	if (dmp->dm_aslen == 0)
376 		return (NULL);
377 
378 	while (hi - lo > 1) {
379 		mid = (lo + hi) / 2;
380 		if (addr >= asmap[mid]->st_value)
381 			lo = mid;
382 		else
383 			hi = mid;
384 	}
385 
386 	i = addr < asmap[hi]->st_value ? lo : hi;
387 	sym = asmap[i];
388 	v = sym->st_value;
389 
390 	/*
391 	 * If the previous entry has the same value, improve our choice.  The
392 	 * order of equal-valued symbols is determined by the comparison func.
393 	 */
394 	while (i-- != 0 && asmap[i]->st_value == v)
395 		sym = asmap[i];
396 
397 	if (addr - sym->st_value < MAX(sym->st_size, 1)) {
398 		if (idp != NULL)
399 			*idp = (uint_t)(sym - symtab);
400 		return (dt_module_symgelf32(sym, symp));
401 	}
402 
403 	return (NULL);
404 }
405 
406 static GElf_Sym *
407 dt_module_symaddr64(dt_module_t *dmp, GElf_Addr addr,
408     GElf_Sym *symp, uint_t *idp)
409 {
410 	const Elf64_Sym **asmap = (const Elf64_Sym **)dmp->dm_asmap;
411 	const Elf64_Sym *symtab = dmp->dm_symtab.cts_data;
412 	const Elf64_Sym *sym;
413 
414 	uint_t i, mid, lo = 0, hi = dmp->dm_aslen - 1;
415 	Elf64_Addr v;
416 
417 	if (dmp->dm_aslen == 0)
418 		return (NULL);
419 
420 	while (hi - lo > 1) {
421 		mid = (lo + hi) / 2;
422 		if (addr >= asmap[mid]->st_value)
423 			lo = mid;
424 		else
425 			hi = mid;
426 	}
427 
428 	i = addr < asmap[hi]->st_value ? lo : hi;
429 	sym = asmap[i];
430 	v = sym->st_value;
431 
432 	/*
433 	 * If the previous entry has the same value, improve our choice.  The
434 	 * order of equal-valued symbols is determined by the comparison func.
435 	 */
436 	while (i-- != 0 && asmap[i]->st_value == v)
437 		sym = asmap[i];
438 
439 	if (addr - sym->st_value < MAX(sym->st_size, 1)) {
440 		if (idp != NULL)
441 			*idp = (uint_t)(sym - symtab);
442 		return (dt_module_symgelf64(sym, symp));
443 	}
444 
445 	return (NULL);
446 }
447 
448 static const dt_modops_t dt_modops_32 = {
449 	dt_module_syminit32,
450 	dt_module_symsort32,
451 	dt_module_symname32,
452 	dt_module_symaddr32
453 };
454 
455 static const dt_modops_t dt_modops_64 = {
456 	dt_module_syminit64,
457 	dt_module_symsort64,
458 	dt_module_symname64,
459 	dt_module_symaddr64
460 };
461 
462 dt_module_t *
463 dt_module_create(dtrace_hdl_t *dtp, const char *name)
464 {
465 	uint_t h = dt_strtab_hash(name, NULL) % dtp->dt_modbuckets;
466 	dt_module_t *dmp;
467 
468 	for (dmp = dtp->dt_mods[h]; dmp != NULL; dmp = dmp->dm_next) {
469 		if (strcmp(dmp->dm_name, name) == 0)
470 			return (dmp);
471 	}
472 
473 	if ((dmp = malloc(sizeof (dt_module_t))) == NULL)
474 		return (NULL); /* caller must handle allocation failure */
475 
476 	bzero(dmp, sizeof (dt_module_t));
477 	(void) strlcpy(dmp->dm_name, name, sizeof (dmp->dm_name));
478 	dt_list_append(&dtp->dt_modlist, dmp);
479 	dmp->dm_next = dtp->dt_mods[h];
480 	dtp->dt_mods[h] = dmp;
481 	dtp->dt_nmods++;
482 
483 	if (dtp->dt_conf.dtc_ctfmodel == CTF_MODEL_LP64)
484 		dmp->dm_ops = &dt_modops_64;
485 	else
486 		dmp->dm_ops = &dt_modops_32;
487 
488 	return (dmp);
489 }
490 
491 dt_module_t *
492 dt_module_lookup_by_name(dtrace_hdl_t *dtp, const char *name)
493 {
494 	uint_t h = dt_strtab_hash(name, NULL) % dtp->dt_modbuckets;
495 	dt_module_t *dmp;
496 
497 	for (dmp = dtp->dt_mods[h]; dmp != NULL; dmp = dmp->dm_next) {
498 		if (strcmp(dmp->dm_name, name) == 0)
499 			return (dmp);
500 	}
501 
502 	return (NULL);
503 }
504 
505 /*ARGSUSED*/
506 dt_module_t *
507 dt_module_lookup_by_ctf(dtrace_hdl_t *dtp, ctf_file_t *ctfp)
508 {
509 	return (ctfp ? ctf_getspecific(ctfp) : NULL);
510 }
511 
512 static int
513 dt_module_load_sect(dtrace_hdl_t *dtp, dt_module_t *dmp, ctf_sect_t *ctsp)
514 {
515 	const char *s;
516 	size_t shstrs;
517 	GElf_Shdr sh;
518 	Elf_Data *dp;
519 	Elf_Scn *sp;
520 
521 	if (elf_getshdrstrndx(dmp->dm_elf, &shstrs) == -1)
522 		return (dt_set_errno(dtp, EDT_NOTLOADED));
523 
524 	for (sp = NULL; (sp = elf_nextscn(dmp->dm_elf, sp)) != NULL; ) {
525 		if (gelf_getshdr(sp, &sh) == NULL || sh.sh_type == SHT_NULL ||
526 		    (s = elf_strptr(dmp->dm_elf, shstrs, sh.sh_name)) == NULL)
527 			continue; /* skip any malformed sections */
528 
529 		if (sh.sh_type == ctsp->cts_type &&
530 		    sh.sh_entsize == ctsp->cts_entsize &&
531 		    strcmp(s, ctsp->cts_name) == 0)
532 			break; /* section matches specification */
533 	}
534 
535 	/*
536 	 * If the section isn't found, return success but leave cts_data set
537 	 * to NULL and cts_size set to zero for our caller.
538 	 */
539 	if (sp == NULL || (dp = elf_getdata(sp, NULL)) == NULL)
540 		return (0);
541 
542 #if defined(sun)
543 	ctsp->cts_data = dp->d_buf;
544 #else
545 	if ((ctsp->cts_data = malloc(dp->d_size)) == NULL)
546 		return (0);
547 	memcpy(ctsp->cts_data, dp->d_buf, dp->d_size);
548 #endif
549 	ctsp->cts_size = dp->d_size;
550 
551 	dt_dprintf("loaded %s [%s] (%lu bytes)\n",
552 	    dmp->dm_name, ctsp->cts_name, (ulong_t)ctsp->cts_size);
553 
554 	return (0);
555 }
556 
557 int
558 dt_module_load(dtrace_hdl_t *dtp, dt_module_t *dmp)
559 {
560 	if (dmp->dm_flags & DT_DM_LOADED)
561 		return (0); /* module is already loaded */
562 
563 	dmp->dm_ctdata.cts_name = ".SUNW_ctf";
564 	dmp->dm_ctdata.cts_type = SHT_PROGBITS;
565 	dmp->dm_ctdata.cts_flags = 0;
566 	dmp->dm_ctdata.cts_data = NULL;
567 	dmp->dm_ctdata.cts_size = 0;
568 	dmp->dm_ctdata.cts_entsize = 0;
569 	dmp->dm_ctdata.cts_offset = 0;
570 
571 	dmp->dm_symtab.cts_name = ".symtab";
572 	dmp->dm_symtab.cts_type = SHT_SYMTAB;
573 	dmp->dm_symtab.cts_flags = 0;
574 	dmp->dm_symtab.cts_data = NULL;
575 	dmp->dm_symtab.cts_size = 0;
576 	dmp->dm_symtab.cts_entsize = dmp->dm_ops == &dt_modops_64 ?
577 	    sizeof (Elf64_Sym) : sizeof (Elf32_Sym);
578 	dmp->dm_symtab.cts_offset = 0;
579 
580 	dmp->dm_strtab.cts_name = ".strtab";
581 	dmp->dm_strtab.cts_type = SHT_STRTAB;
582 	dmp->dm_strtab.cts_flags = 0;
583 	dmp->dm_strtab.cts_data = NULL;
584 	dmp->dm_strtab.cts_size = 0;
585 	dmp->dm_strtab.cts_entsize = 0;
586 	dmp->dm_strtab.cts_offset = 0;
587 
588 	/*
589 	 * Attempt to load the module's CTF section, symbol table section, and
590 	 * string table section.  Note that modules may not contain CTF data:
591 	 * this will result in a successful load_sect but data of size zero.
592 	 * We will then fail if dt_module_getctf() is called, as shown below.
593 	 */
594 	if (dt_module_load_sect(dtp, dmp, &dmp->dm_ctdata) == -1 ||
595 	    dt_module_load_sect(dtp, dmp, &dmp->dm_symtab) == -1 ||
596 	    dt_module_load_sect(dtp, dmp, &dmp->dm_strtab) == -1) {
597 		dt_module_unload(dtp, dmp);
598 		return (-1); /* dt_errno is set for us */
599 	}
600 
601 	/*
602 	 * Allocate the hash chains and hash buckets for symbol name lookup.
603 	 * This is relatively simple since the symbol table is of fixed size
604 	 * and is known in advance.  We allocate one extra element since we
605 	 * use element indices instead of pointers and zero is our sentinel.
606 	 */
607 	dmp->dm_nsymelems =
608 	    dmp->dm_symtab.cts_size / dmp->dm_symtab.cts_entsize;
609 
610 	dmp->dm_nsymbuckets = _dtrace_strbuckets;
611 	dmp->dm_symfree = 1;		/* first free element is index 1 */
612 
613 	dmp->dm_symbuckets = malloc(sizeof (uint_t) * dmp->dm_nsymbuckets);
614 	dmp->dm_symchains = malloc(sizeof (dt_sym_t) * dmp->dm_nsymelems + 1);
615 
616 	if (dmp->dm_symbuckets == NULL || dmp->dm_symchains == NULL) {
617 		dt_module_unload(dtp, dmp);
618 		return (dt_set_errno(dtp, EDT_NOMEM));
619 	}
620 
621 	bzero(dmp->dm_symbuckets, sizeof (uint_t) * dmp->dm_nsymbuckets);
622 	bzero(dmp->dm_symchains, sizeof (dt_sym_t) * dmp->dm_nsymelems + 1);
623 
624 	/*
625 	 * Iterate over the symbol table data buffer and insert each symbol
626 	 * name into the name hash if the name and type are valid.  Then
627 	 * allocate the address map, fill it in, and sort it.
628 	 */
629 	dmp->dm_asrsv = dmp->dm_ops->do_syminit(dmp);
630 
631 	dt_dprintf("hashed %s [%s] (%u symbols)\n",
632 	    dmp->dm_name, dmp->dm_symtab.cts_name, dmp->dm_symfree - 1);
633 
634 	if ((dmp->dm_asmap = malloc(sizeof (void *) * dmp->dm_asrsv)) == NULL) {
635 		dt_module_unload(dtp, dmp);
636 		return (dt_set_errno(dtp, EDT_NOMEM));
637 	}
638 
639 	dmp->dm_ops->do_symsort(dmp);
640 
641 	dt_dprintf("sorted %s [%s] (%u symbols)\n",
642 	    dmp->dm_name, dmp->dm_symtab.cts_name, dmp->dm_aslen);
643 
644 	dmp->dm_flags |= DT_DM_LOADED;
645 	return (0);
646 }
647 
648 ctf_file_t *
649 dt_module_getctf(dtrace_hdl_t *dtp, dt_module_t *dmp)
650 {
651 	const char *parent;
652 	dt_module_t *pmp;
653 	ctf_file_t *pfp;
654 	int model;
655 
656 	if (dmp->dm_ctfp != NULL || dt_module_load(dtp, dmp) != 0)
657 		return (dmp->dm_ctfp);
658 
659 	if (dmp->dm_ops == &dt_modops_64)
660 		model = CTF_MODEL_LP64;
661 	else
662 		model = CTF_MODEL_ILP32;
663 
664 	/*
665 	 * If the data model of the module does not match our program data
666 	 * model, then do not permit CTF from this module to be opened and
667 	 * returned to the compiler.  If we support mixed data models in the
668 	 * future for combined kernel/user tracing, this can be removed.
669 	 */
670 	if (dtp->dt_conf.dtc_ctfmodel != model) {
671 		(void) dt_set_errno(dtp, EDT_DATAMODEL);
672 		return (NULL);
673 	}
674 
675 	if (dmp->dm_ctdata.cts_size == 0) {
676 		(void) dt_set_errno(dtp, EDT_NOCTF);
677 		return (NULL);
678 	}
679 
680 	dmp->dm_ctfp = ctf_bufopen(&dmp->dm_ctdata,
681 	    &dmp->dm_symtab, &dmp->dm_strtab, &dtp->dt_ctferr);
682 
683 	if (dmp->dm_ctfp == NULL) {
684 		(void) dt_set_errno(dtp, EDT_CTF);
685 		return (NULL);
686 	}
687 
688 	(void) ctf_setmodel(dmp->dm_ctfp, model);
689 	ctf_setspecific(dmp->dm_ctfp, dmp);
690 
691 	if ((parent = ctf_parent_name(dmp->dm_ctfp)) != NULL) {
692 		if ((pmp = dt_module_create(dtp, parent)) == NULL ||
693 		    (pfp = dt_module_getctf(dtp, pmp)) == NULL) {
694 			if (pmp == NULL)
695 				(void) dt_set_errno(dtp, EDT_NOMEM);
696 			goto err;
697 		}
698 
699 		if (ctf_import(dmp->dm_ctfp, pfp) == CTF_ERR) {
700 			dtp->dt_ctferr = ctf_errno(dmp->dm_ctfp);
701 			(void) dt_set_errno(dtp, EDT_CTF);
702 			goto err;
703 		}
704 	}
705 
706 	dt_dprintf("loaded CTF container for %s (%p)\n",
707 	    dmp->dm_name, (void *)dmp->dm_ctfp);
708 
709 	return (dmp->dm_ctfp);
710 
711 err:
712 	ctf_close(dmp->dm_ctfp);
713 	dmp->dm_ctfp = NULL;
714 	return (NULL);
715 }
716 
717 /*ARGSUSED*/
718 void
719 dt_module_unload(dtrace_hdl_t *dtp, dt_module_t *dmp)
720 {
721 	ctf_close(dmp->dm_ctfp);
722 	dmp->dm_ctfp = NULL;
723 
724 #if !defined(sun)
725 	if (dmp->dm_ctdata.cts_data != NULL) {
726 		free(dmp->dm_ctdata.cts_data);
727 	}
728 	if (dmp->dm_symtab.cts_data != NULL) {
729 		free(dmp->dm_symtab.cts_data);
730 	}
731 	if (dmp->dm_strtab.cts_data != NULL) {
732 		free(dmp->dm_strtab.cts_data);
733 	}
734 #endif
735 
736 	bzero(&dmp->dm_ctdata, sizeof (ctf_sect_t));
737 	bzero(&dmp->dm_symtab, sizeof (ctf_sect_t));
738 	bzero(&dmp->dm_strtab, sizeof (ctf_sect_t));
739 
740 	if (dmp->dm_symbuckets != NULL) {
741 		free(dmp->dm_symbuckets);
742 		dmp->dm_symbuckets = NULL;
743 	}
744 
745 	if (dmp->dm_symchains != NULL) {
746 		free(dmp->dm_symchains);
747 		dmp->dm_symchains = NULL;
748 	}
749 
750 	if (dmp->dm_asmap != NULL) {
751 		free(dmp->dm_asmap);
752 		dmp->dm_asmap = NULL;
753 	}
754 #if defined(__FreeBSD__)
755 	if (dmp->dm_sec_offsets != NULL) {
756 		free(dmp->dm_sec_offsets);
757 		dmp->dm_sec_offsets = NULL;
758 	}
759 #endif
760 	dmp->dm_symfree = 0;
761 	dmp->dm_nsymbuckets = 0;
762 	dmp->dm_nsymelems = 0;
763 	dmp->dm_asrsv = 0;
764 	dmp->dm_aslen = 0;
765 
766 	dmp->dm_text_va = 0;
767 	dmp->dm_text_size = 0;
768 	dmp->dm_data_va = 0;
769 	dmp->dm_data_size = 0;
770 	dmp->dm_bss_va = 0;
771 	dmp->dm_bss_size = 0;
772 
773 	if (dmp->dm_extern != NULL) {
774 		dt_idhash_destroy(dmp->dm_extern);
775 		dmp->dm_extern = NULL;
776 	}
777 
778 	(void) elf_end(dmp->dm_elf);
779 	dmp->dm_elf = NULL;
780 
781 	dmp->dm_flags &= ~DT_DM_LOADED;
782 }
783 
784 void
785 dt_module_destroy(dtrace_hdl_t *dtp, dt_module_t *dmp)
786 {
787 	uint_t h = dt_strtab_hash(dmp->dm_name, NULL) % dtp->dt_modbuckets;
788 	dt_module_t **dmpp = &dtp->dt_mods[h];
789 
790 	dt_list_delete(&dtp->dt_modlist, dmp);
791 	assert(dtp->dt_nmods != 0);
792 	dtp->dt_nmods--;
793 
794 	/*
795 	 * Now remove this module from its hash chain.  We expect to always
796 	 * find the module on its hash chain, so in this loop we assert that
797 	 * we don't run off the end of the list.
798 	 */
799 	while (*dmpp != dmp) {
800 		dmpp = &((*dmpp)->dm_next);
801 		assert(*dmpp != NULL);
802 	}
803 
804 	*dmpp = dmp->dm_next;
805 
806 	dt_module_unload(dtp, dmp);
807 	free(dmp);
808 }
809 
810 /*
811  * Insert a new external symbol reference into the specified module.  The new
812  * symbol will be marked as undefined and is assigned a symbol index beyond
813  * any existing cached symbols from this module.  We use the ident's di_data
814  * field to store a pointer to a copy of the dtrace_syminfo_t for this symbol.
815  */
816 dt_ident_t *
817 dt_module_extern(dtrace_hdl_t *dtp, dt_module_t *dmp,
818     const char *name, const dtrace_typeinfo_t *tip)
819 {
820 	dtrace_syminfo_t *sip;
821 	dt_ident_t *idp;
822 	uint_t id;
823 
824 	if (dmp->dm_extern == NULL && (dmp->dm_extern = dt_idhash_create(
825 	    "extern", NULL, dmp->dm_nsymelems, UINT_MAX)) == NULL) {
826 		(void) dt_set_errno(dtp, EDT_NOMEM);
827 		return (NULL);
828 	}
829 
830 	if (dt_idhash_nextid(dmp->dm_extern, &id) == -1) {
831 		(void) dt_set_errno(dtp, EDT_SYMOFLOW);
832 		return (NULL);
833 	}
834 
835 	if ((sip = malloc(sizeof (dtrace_syminfo_t))) == NULL) {
836 		(void) dt_set_errno(dtp, EDT_NOMEM);
837 		return (NULL);
838 	}
839 
840 	idp = dt_idhash_insert(dmp->dm_extern, name, DT_IDENT_SYMBOL, 0, id,
841 	    _dtrace_symattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen);
842 
843 	if (idp == NULL) {
844 		(void) dt_set_errno(dtp, EDT_NOMEM);
845 		free(sip);
846 		return (NULL);
847 	}
848 
849 	sip->dts_object = dmp->dm_name;
850 	sip->dts_name = idp->di_name;
851 	sip->dts_id = idp->di_id;
852 
853 	idp->di_data = sip;
854 	idp->di_ctfp = tip->dtt_ctfp;
855 	idp->di_type = tip->dtt_type;
856 
857 	return (idp);
858 }
859 
860 const char *
861 dt_module_modelname(dt_module_t *dmp)
862 {
863 	if (dmp->dm_ops == &dt_modops_64)
864 		return ("64-bit");
865 	else
866 		return ("32-bit");
867 }
868 
869 /*
870  * Update our module cache by adding an entry for the specified module 'name'.
871  * We create the dt_module_t and populate it using /system/object/<name>/.
872  *
873  * On FreeBSD, the module name is passed as the full module file name,
874  * including the path.
875  */
876 static void
877 #if defined(sun)
878 dt_module_update(dtrace_hdl_t *dtp, const char *name)
879 #else
880 dt_module_update(dtrace_hdl_t *dtp, struct kld_file_stat *k_stat)
881 #endif
882 {
883 	char fname[MAXPATHLEN];
884 	struct stat64 st;
885 	int fd, err, bits;
886 
887 	dt_module_t *dmp;
888 	const char *s;
889 	size_t shstrs;
890 	GElf_Shdr sh;
891 	Elf_Data *dp;
892 	Elf_Scn *sp;
893 
894 #if defined(sun)
895 	(void) snprintf(fname, sizeof (fname),
896 	    "%s/%s/object", OBJFS_ROOT, name);
897 #else
898 	GElf_Ehdr ehdr;
899 	GElf_Phdr ph;
900 	char name[MAXPATHLEN];
901 	uintptr_t mapbase, alignmask;
902 	int i = 0;
903 	int is_elf_obj;
904 
905 	(void) strlcpy(name, k_stat->name, sizeof(name));
906 	(void) strlcpy(fname, k_stat->pathname, sizeof(fname));
907 #endif
908 
909 	if ((fd = open(fname, O_RDONLY)) == -1 || fstat64(fd, &st) == -1 ||
910 	    (dmp = dt_module_create(dtp, name)) == NULL) {
911 		dt_dprintf("failed to open %s: %s\n", fname, strerror(errno));
912 		(void) close(fd);
913 		return;
914 	}
915 
916 	/*
917 	 * Since the module can unload out from under us (and /system/object
918 	 * will return ENOENT), tell libelf to cook the entire file now and
919 	 * then close the underlying file descriptor immediately.  If this
920 	 * succeeds, we know that we can continue safely using dmp->dm_elf.
921 	 */
922 	dmp->dm_elf = elf_begin(fd, ELF_C_READ, NULL);
923 	err = elf_cntl(dmp->dm_elf, ELF_C_FDREAD);
924 	(void) close(fd);
925 
926 	if (dmp->dm_elf == NULL || err == -1 ||
927 	    elf_getshdrstrndx(dmp->dm_elf, &shstrs) == -1) {
928 		dt_dprintf("failed to load %s: %s\n",
929 		    fname, elf_errmsg(elf_errno()));
930 		dt_module_destroy(dtp, dmp);
931 		return;
932 	}
933 
934 	switch (gelf_getclass(dmp->dm_elf)) {
935 	case ELFCLASS32:
936 		dmp->dm_ops = &dt_modops_32;
937 		bits = 32;
938 		break;
939 	case ELFCLASS64:
940 		dmp->dm_ops = &dt_modops_64;
941 		bits = 64;
942 		break;
943 	default:
944 		dt_dprintf("failed to load %s: unknown ELF class\n", fname);
945 		dt_module_destroy(dtp, dmp);
946 		return;
947 	}
948 #if defined(__FreeBSD__)
949 	mapbase = (uintptr_t)k_stat->address;
950 	gelf_getehdr(dmp->dm_elf, &ehdr);
951 	is_elf_obj = (ehdr.e_type == ET_REL);
952 	if (is_elf_obj) {
953 		dmp->dm_sec_offsets =
954 		    malloc(ehdr.e_shnum * sizeof(*dmp->dm_sec_offsets));
955 		if (dmp->dm_sec_offsets == NULL) {
956 			dt_dprintf("failed to allocate memory\n");
957 			dt_module_destroy(dtp, dmp);
958 			return;
959 		}
960 	}
961 #endif
962 	/*
963 	 * Iterate over the section headers locating various sections of
964 	 * interest and use their attributes to flesh out the dt_module_t.
965 	 */
966 	for (sp = NULL; (sp = elf_nextscn(dmp->dm_elf, sp)) != NULL; ) {
967 		if (gelf_getshdr(sp, &sh) == NULL || sh.sh_type == SHT_NULL ||
968 		    (s = elf_strptr(dmp->dm_elf, shstrs, sh.sh_name)) == NULL)
969 			continue; /* skip any malformed sections */
970 #if defined(__FreeBSD__)
971 		if (sh.sh_size == 0)
972 			continue;
973 		if (is_elf_obj && (sh.sh_type == SHT_PROGBITS ||
974 		    sh.sh_type == SHT_NOBITS)) {
975 			alignmask = sh.sh_addralign - 1;
976 			mapbase += alignmask;
977 			mapbase &= ~alignmask;
978 			sh.sh_addr = mapbase;
979 			dmp->dm_sec_offsets[elf_ndxscn(sp)] = sh.sh_addr;
980 			mapbase += sh.sh_size;
981 		}
982 #endif
983 		if (strcmp(s, ".text") == 0) {
984 			dmp->dm_text_size = sh.sh_size;
985 			dmp->dm_text_va = sh.sh_addr;
986 		} else if (strcmp(s, ".data") == 0) {
987 			dmp->dm_data_size = sh.sh_size;
988 			dmp->dm_data_va = sh.sh_addr;
989 		} else if (strcmp(s, ".bss") == 0) {
990 			dmp->dm_bss_size = sh.sh_size;
991 			dmp->dm_bss_va = sh.sh_addr;
992 		} else if (strcmp(s, ".info") == 0 &&
993 		    (dp = elf_getdata(sp, NULL)) != NULL) {
994 			bcopy(dp->d_buf, &dmp->dm_info,
995 			    MIN(sh.sh_size, sizeof (dmp->dm_info)));
996 		} else if (strcmp(s, ".filename") == 0 &&
997 		    (dp = elf_getdata(sp, NULL)) != NULL) {
998 			(void) strlcpy(dmp->dm_file,
999 			    dp->d_buf, sizeof (dmp->dm_file));
1000 		}
1001 	}
1002 
1003 	dmp->dm_flags |= DT_DM_KERNEL;
1004 #if defined(sun)
1005 	dmp->dm_modid = (int)OBJFS_MODID(st.st_ino);
1006 #else
1007 	/*
1008 	 * Include .rodata and special sections into .text.
1009 	 * This depends on default section layout produced by GNU ld
1010 	 * for ELF objects and libraries:
1011 	 * [Text][R/O data][R/W data][Dynamic][BSS][Non loadable]
1012 	 */
1013 	dmp->dm_text_size = dmp->dm_data_va - dmp->dm_text_va;
1014 #if defined(__i386__)
1015 	/*
1016 	 * Find the first load section and figure out the relocation
1017 	 * offset for the symbols. The kernel module will not need
1018 	 * relocation, but the kernel linker modules will.
1019 	 */
1020 	for (i = 0; gelf_getphdr(dmp->dm_elf, i, &ph) != NULL; i++) {
1021 		if (ph.p_type == PT_LOAD) {
1022 			dmp->dm_reloc_offset = k_stat->address - ph.p_vaddr;
1023 			break;
1024 		}
1025 	}
1026 #endif
1027 #endif
1028 
1029 	if (dmp->dm_info.objfs_info_primary)
1030 		dmp->dm_flags |= DT_DM_PRIMARY;
1031 
1032 	dt_dprintf("opened %d-bit module %s (%s) [%d]\n",
1033 	    bits, dmp->dm_name, dmp->dm_file, dmp->dm_modid);
1034 }
1035 
1036 /*
1037  * Unload all the loaded modules and then refresh the module cache with the
1038  * latest list of loaded modules and their address ranges.
1039  */
1040 void
1041 dtrace_update(dtrace_hdl_t *dtp)
1042 {
1043 	dt_module_t *dmp;
1044 	DIR *dirp;
1045 #if defined(__FreeBSD__)
1046 	int fileid;
1047 #endif
1048 
1049 	for (dmp = dt_list_next(&dtp->dt_modlist);
1050 	    dmp != NULL; dmp = dt_list_next(dmp))
1051 		dt_module_unload(dtp, dmp);
1052 
1053 #if defined(sun)
1054 	/*
1055 	 * Open /system/object and attempt to create a libdtrace module for
1056 	 * each kernel module that is loaded on the current system.
1057 	 */
1058 	if (!(dtp->dt_oflags & DTRACE_O_NOSYS) &&
1059 	    (dirp = opendir(OBJFS_ROOT)) != NULL) {
1060 		struct dirent *dp;
1061 
1062 		while ((dp = readdir(dirp)) != NULL) {
1063 			if (dp->d_name[0] != '.')
1064 				dt_module_update(dtp, dp->d_name);
1065 		}
1066 
1067 		(void) closedir(dirp);
1068 	}
1069 #elif defined(__FreeBSD__)
1070 	/*
1071 	 * Use FreeBSD's kernel loader interface to discover what kernel
1072 	 * modules are loaded and create a libdtrace module for each one.
1073 	 */
1074 	for (fileid = kldnext(0); fileid > 0; fileid = kldnext(fileid)) {
1075 		struct kld_file_stat k_stat;
1076 		k_stat.version = sizeof(k_stat);
1077 		if (kldstat(fileid, &k_stat) == 0)
1078 			dt_module_update(dtp, &k_stat);
1079 	}
1080 #endif
1081 
1082 	/*
1083 	 * Look up all the macro identifiers and set di_id to the latest value.
1084 	 * This code collaborates with dt_lex.l on the use of di_id.  We will
1085 	 * need to implement something fancier if we need to support non-ints.
1086 	 */
1087 	dt_idhash_lookup(dtp->dt_macros, "egid")->di_id = getegid();
1088 	dt_idhash_lookup(dtp->dt_macros, "euid")->di_id = geteuid();
1089 	dt_idhash_lookup(dtp->dt_macros, "gid")->di_id = getgid();
1090 	dt_idhash_lookup(dtp->dt_macros, "pid")->di_id = getpid();
1091 	dt_idhash_lookup(dtp->dt_macros, "pgid")->di_id = getpgid(0);
1092 	dt_idhash_lookup(dtp->dt_macros, "ppid")->di_id = getppid();
1093 #if defined(sun)
1094 	dt_idhash_lookup(dtp->dt_macros, "projid")->di_id = getprojid();
1095 #endif
1096 	dt_idhash_lookup(dtp->dt_macros, "sid")->di_id = getsid(0);
1097 #if defined(sun)
1098 	dt_idhash_lookup(dtp->dt_macros, "taskid")->di_id = gettaskid();
1099 #endif
1100 	dt_idhash_lookup(dtp->dt_macros, "uid")->di_id = getuid();
1101 
1102 	/*
1103 	 * Cache the pointers to the modules representing the base executable
1104 	 * and the run-time linker in the dtrace client handle. Note that on
1105 	 * x86 krtld is folded into unix, so if we don't find it, use unix
1106 	 * instead.
1107 	 */
1108 	dtp->dt_exec = dt_module_lookup_by_name(dtp, "genunix");
1109 	dtp->dt_rtld = dt_module_lookup_by_name(dtp, "krtld");
1110 	if (dtp->dt_rtld == NULL)
1111 		dtp->dt_rtld = dt_module_lookup_by_name(dtp, "unix");
1112 
1113 	/*
1114 	 * If this is the first time we are initializing the module list,
1115 	 * remove the module for genunix from the module list and then move it
1116 	 * to the front of the module list.  We do this so that type and symbol
1117 	 * queries encounter genunix and thereby optimize for the common case
1118 	 * in dtrace_lookup_by_name() and dtrace_lookup_by_type(), below.
1119 	 */
1120 	if (dtp->dt_exec != NULL &&
1121 	    dtp->dt_cdefs == NULL && dtp->dt_ddefs == NULL) {
1122 		dt_list_delete(&dtp->dt_modlist, dtp->dt_exec);
1123 		dt_list_prepend(&dtp->dt_modlist, dtp->dt_exec);
1124 	}
1125 }
1126 
1127 static dt_module_t *
1128 dt_module_from_object(dtrace_hdl_t *dtp, const char *object)
1129 {
1130 	int err = EDT_NOMOD;
1131 	dt_module_t *dmp;
1132 
1133 	switch ((uintptr_t)object) {
1134 	case (uintptr_t)DTRACE_OBJ_EXEC:
1135 		dmp = dtp->dt_exec;
1136 		break;
1137 	case (uintptr_t)DTRACE_OBJ_RTLD:
1138 		dmp = dtp->dt_rtld;
1139 		break;
1140 	case (uintptr_t)DTRACE_OBJ_CDEFS:
1141 		dmp = dtp->dt_cdefs;
1142 		break;
1143 	case (uintptr_t)DTRACE_OBJ_DDEFS:
1144 		dmp = dtp->dt_ddefs;
1145 		break;
1146 	default:
1147 		dmp = dt_module_create(dtp, object);
1148 		err = EDT_NOMEM;
1149 	}
1150 
1151 	if (dmp == NULL)
1152 		(void) dt_set_errno(dtp, err);
1153 
1154 	return (dmp);
1155 }
1156 
1157 /*
1158  * Exported interface to look up a symbol by name.  We return the GElf_Sym and
1159  * complete symbol information for the matching symbol.
1160  */
1161 int
1162 dtrace_lookup_by_name(dtrace_hdl_t *dtp, const char *object, const char *name,
1163     GElf_Sym *symp, dtrace_syminfo_t *sip)
1164 {
1165 	dt_module_t *dmp;
1166 	dt_ident_t *idp;
1167 	uint_t n, id;
1168 	GElf_Sym sym;
1169 
1170 	uint_t mask = 0; /* mask of dt_module flags to match */
1171 	uint_t bits = 0; /* flag bits that must be present */
1172 
1173 	if (object != DTRACE_OBJ_EVERY &&
1174 	    object != DTRACE_OBJ_KMODS &&
1175 	    object != DTRACE_OBJ_UMODS) {
1176 		if ((dmp = dt_module_from_object(dtp, object)) == NULL)
1177 			return (-1); /* dt_errno is set for us */
1178 
1179 		if (dt_module_load(dtp, dmp) == -1)
1180 			return (-1); /* dt_errno is set for us */
1181 		n = 1;
1182 
1183 	} else {
1184 		if (object == DTRACE_OBJ_KMODS)
1185 			mask = bits = DT_DM_KERNEL;
1186 		else if (object == DTRACE_OBJ_UMODS)
1187 			mask = DT_DM_KERNEL;
1188 
1189 		dmp = dt_list_next(&dtp->dt_modlist);
1190 		n = dtp->dt_nmods;
1191 	}
1192 
1193 	if (symp == NULL)
1194 		symp = &sym;
1195 
1196 	for (; n > 0; n--, dmp = dt_list_next(dmp)) {
1197 		if ((dmp->dm_flags & mask) != bits)
1198 			continue; /* failed to match required attributes */
1199 
1200 		if (dt_module_load(dtp, dmp) == -1)
1201 			continue; /* failed to load symbol table */
1202 
1203 		if (dmp->dm_ops->do_symname(dmp, name, symp, &id) != NULL) {
1204 			if (sip != NULL) {
1205 				sip->dts_object = dmp->dm_name;
1206 				sip->dts_name = (const char *)
1207 				    dmp->dm_strtab.cts_data + symp->st_name;
1208 				sip->dts_id = id;
1209 			}
1210 			return (0);
1211 		}
1212 
1213 		if (dmp->dm_extern != NULL &&
1214 		    (idp = dt_idhash_lookup(dmp->dm_extern, name)) != NULL) {
1215 			if (symp != &sym) {
1216 				symp->st_name = (uintptr_t)idp->di_name;
1217 				symp->st_info =
1218 				    GELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
1219 				symp->st_other = 0;
1220 				symp->st_shndx = SHN_UNDEF;
1221 				symp->st_value = 0;
1222 				symp->st_size =
1223 				    ctf_type_size(idp->di_ctfp, idp->di_type);
1224 			}
1225 
1226 			if (sip != NULL) {
1227 				sip->dts_object = dmp->dm_name;
1228 				sip->dts_name = idp->di_name;
1229 				sip->dts_id = idp->di_id;
1230 			}
1231 
1232 			return (0);
1233 		}
1234 	}
1235 
1236 	return (dt_set_errno(dtp, EDT_NOSYM));
1237 }
1238 
1239 /*
1240  * Exported interface to look up a symbol by address.  We return the GElf_Sym
1241  * and complete symbol information for the matching symbol.
1242  */
1243 int
1244 dtrace_lookup_by_addr(dtrace_hdl_t *dtp, GElf_Addr addr,
1245     GElf_Sym *symp, dtrace_syminfo_t *sip)
1246 {
1247 	dt_module_t *dmp;
1248 	uint_t id;
1249 	const dtrace_vector_t *v = dtp->dt_vector;
1250 
1251 	if (v != NULL)
1252 		return (v->dtv_lookup_by_addr(dtp->dt_varg, addr, symp, sip));
1253 
1254 	for (dmp = dt_list_next(&dtp->dt_modlist); dmp != NULL;
1255 	    dmp = dt_list_next(dmp)) {
1256 		if (addr - dmp->dm_text_va < dmp->dm_text_size ||
1257 		    addr - dmp->dm_data_va < dmp->dm_data_size ||
1258 		    addr - dmp->dm_bss_va < dmp->dm_bss_size)
1259 			break;
1260 	}
1261 
1262 	if (dmp == NULL)
1263 		return (dt_set_errno(dtp, EDT_NOSYMADDR));
1264 
1265 	if (dt_module_load(dtp, dmp) == -1)
1266 		return (-1); /* dt_errno is set for us */
1267 
1268 	if (symp != NULL) {
1269 		if (dmp->dm_ops->do_symaddr(dmp, addr, symp, &id) == NULL)
1270 			return (dt_set_errno(dtp, EDT_NOSYMADDR));
1271 	}
1272 
1273 	if (sip != NULL) {
1274 		sip->dts_object = dmp->dm_name;
1275 
1276 		if (symp != NULL) {
1277 			sip->dts_name = (const char *)
1278 			    dmp->dm_strtab.cts_data + symp->st_name;
1279 			sip->dts_id = id;
1280 		} else {
1281 			sip->dts_name = NULL;
1282 			sip->dts_id = 0;
1283 		}
1284 	}
1285 
1286 	return (0);
1287 }
1288 
1289 int
1290 dtrace_lookup_by_type(dtrace_hdl_t *dtp, const char *object, const char *name,
1291     dtrace_typeinfo_t *tip)
1292 {
1293 	dtrace_typeinfo_t ti;
1294 	dt_module_t *dmp;
1295 	int found = 0;
1296 	ctf_id_t id;
1297 	uint_t n;
1298 	int justone;
1299 
1300 	uint_t mask = 0; /* mask of dt_module flags to match */
1301 	uint_t bits = 0; /* flag bits that must be present */
1302 
1303 	if (object != DTRACE_OBJ_EVERY &&
1304 	    object != DTRACE_OBJ_KMODS &&
1305 	    object != DTRACE_OBJ_UMODS) {
1306 		if ((dmp = dt_module_from_object(dtp, object)) == NULL)
1307 			return (-1); /* dt_errno is set for us */
1308 
1309 		if (dt_module_load(dtp, dmp) == -1)
1310 			return (-1); /* dt_errno is set for us */
1311 		n = 1;
1312 		justone = 1;
1313 
1314 	} else {
1315 		if (object == DTRACE_OBJ_KMODS)
1316 			mask = bits = DT_DM_KERNEL;
1317 		else if (object == DTRACE_OBJ_UMODS)
1318 			mask = DT_DM_KERNEL;
1319 
1320 		dmp = dt_list_next(&dtp->dt_modlist);
1321 		n = dtp->dt_nmods;
1322 		justone = 0;
1323 	}
1324 
1325 	if (tip == NULL)
1326 		tip = &ti;
1327 
1328 	for (; n > 0; n--, dmp = dt_list_next(dmp)) {
1329 		if ((dmp->dm_flags & mask) != bits)
1330 			continue; /* failed to match required attributes */
1331 
1332 		/*
1333 		 * If we can't load the CTF container, continue on to the next
1334 		 * module.  If our search was scoped to only one module then
1335 		 * return immediately leaving dt_errno unmodified.
1336 		 */
1337 		if (dt_module_getctf(dtp, dmp) == NULL) {
1338 			if (justone)
1339 				return (-1);
1340 			continue;
1341 		}
1342 
1343 		/*
1344 		 * Look up the type in the module's CTF container.  If our
1345 		 * match is a forward declaration tag, save this choice in
1346 		 * 'tip' and keep going in the hope that we will locate the
1347 		 * underlying structure definition.  Otherwise just return.
1348 		 */
1349 		if ((id = ctf_lookup_by_name(dmp->dm_ctfp, name)) != CTF_ERR) {
1350 			tip->dtt_object = dmp->dm_name;
1351 			tip->dtt_ctfp = dmp->dm_ctfp;
1352 			tip->dtt_type = id;
1353 
1354 			if (ctf_type_kind(dmp->dm_ctfp, ctf_type_resolve(
1355 			    dmp->dm_ctfp, id)) != CTF_K_FORWARD)
1356 				return (0);
1357 
1358 			found++;
1359 		}
1360 	}
1361 
1362 	if (found == 0)
1363 		return (dt_set_errno(dtp, EDT_NOTYPE));
1364 
1365 	return (0);
1366 }
1367 
1368 int
1369 dtrace_symbol_type(dtrace_hdl_t *dtp, const GElf_Sym *symp,
1370     const dtrace_syminfo_t *sip, dtrace_typeinfo_t *tip)
1371 {
1372 	dt_module_t *dmp;
1373 
1374 	tip->dtt_object = NULL;
1375 	tip->dtt_ctfp = NULL;
1376 	tip->dtt_type = CTF_ERR;
1377 
1378 	if ((dmp = dt_module_lookup_by_name(dtp, sip->dts_object)) == NULL)
1379 		return (dt_set_errno(dtp, EDT_NOMOD));
1380 
1381 	if (symp->st_shndx == SHN_UNDEF && dmp->dm_extern != NULL) {
1382 		dt_ident_t *idp =
1383 		    dt_idhash_lookup(dmp->dm_extern, sip->dts_name);
1384 
1385 		if (idp == NULL)
1386 			return (dt_set_errno(dtp, EDT_NOSYM));
1387 
1388 		tip->dtt_ctfp = idp->di_ctfp;
1389 		tip->dtt_type = idp->di_type;
1390 
1391 	} else if (GELF_ST_TYPE(symp->st_info) != STT_FUNC) {
1392 		if (dt_module_getctf(dtp, dmp) == NULL)
1393 			return (-1); /* errno is set for us */
1394 
1395 		tip->dtt_ctfp = dmp->dm_ctfp;
1396 		tip->dtt_type = ctf_lookup_by_symbol(dmp->dm_ctfp, sip->dts_id);
1397 
1398 		if (tip->dtt_type == CTF_ERR) {
1399 			dtp->dt_ctferr = ctf_errno(tip->dtt_ctfp);
1400 			return (dt_set_errno(dtp, EDT_CTF));
1401 		}
1402 
1403 	} else {
1404 		tip->dtt_ctfp = DT_FPTR_CTFP(dtp);
1405 		tip->dtt_type = DT_FPTR_TYPE(dtp);
1406 	}
1407 
1408 	tip->dtt_object = dmp->dm_name;
1409 	return (0);
1410 }
1411 
1412 static dtrace_objinfo_t *
1413 dt_module_info(const dt_module_t *dmp, dtrace_objinfo_t *dto)
1414 {
1415 	dto->dto_name = dmp->dm_name;
1416 	dto->dto_file = dmp->dm_file;
1417 	dto->dto_id = dmp->dm_modid;
1418 	dto->dto_flags = 0;
1419 
1420 	if (dmp->dm_flags & DT_DM_KERNEL)
1421 		dto->dto_flags |= DTRACE_OBJ_F_KERNEL;
1422 	if (dmp->dm_flags & DT_DM_PRIMARY)
1423 		dto->dto_flags |= DTRACE_OBJ_F_PRIMARY;
1424 
1425 	dto->dto_text_va = dmp->dm_text_va;
1426 	dto->dto_text_size = dmp->dm_text_size;
1427 	dto->dto_data_va = dmp->dm_data_va;
1428 	dto->dto_data_size = dmp->dm_data_size;
1429 	dto->dto_bss_va = dmp->dm_bss_va;
1430 	dto->dto_bss_size = dmp->dm_bss_size;
1431 
1432 	return (dto);
1433 }
1434 
1435 int
1436 dtrace_object_iter(dtrace_hdl_t *dtp, dtrace_obj_f *func, void *data)
1437 {
1438 	const dt_module_t *dmp = dt_list_next(&dtp->dt_modlist);
1439 	dtrace_objinfo_t dto;
1440 	int rv;
1441 
1442 	for (; dmp != NULL; dmp = dt_list_next(dmp)) {
1443 		if ((rv = (*func)(dtp, dt_module_info(dmp, &dto), data)) != 0)
1444 			return (rv);
1445 	}
1446 
1447 	return (0);
1448 }
1449 
1450 int
1451 dtrace_object_info(dtrace_hdl_t *dtp, const char *object, dtrace_objinfo_t *dto)
1452 {
1453 	dt_module_t *dmp;
1454 
1455 	if (object == DTRACE_OBJ_EVERY || object == DTRACE_OBJ_KMODS ||
1456 	    object == DTRACE_OBJ_UMODS || dto == NULL)
1457 		return (dt_set_errno(dtp, EINVAL));
1458 
1459 	if ((dmp = dt_module_from_object(dtp, object)) == NULL)
1460 		return (-1); /* dt_errno is set for us */
1461 
1462 	if (dt_module_load(dtp, dmp) == -1)
1463 		return (-1); /* dt_errno is set for us */
1464 
1465 	(void) dt_module_info(dmp, dto);
1466 	return (0);
1467 }
1468