xref: /freebsd/cddl/contrib/opensolaris/common/ctf/ctf_open.c (revision 13ec1e3155c7e9bf037b12af186351b7fa9b9450)
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 /*
28  * Copyright (c) 2013, Joyent, Inc.  All rights reserved.
29  */
30 
31 #include <ctf_impl.h>
32 #include <sys/mman.h>
33 #include <sys/zmod.h>
34 
35 static const ctf_dmodel_t _libctf_models[] = {
36 	{ "ILP32", CTF_MODEL_ILP32, 4, 1, 2, 4, 4 },
37 	{ "LP64", CTF_MODEL_LP64, 8, 1, 2, 4, 8 },
38 	{ NULL, 0, 0, 0, 0, 0, 0 }
39 };
40 
41 const char _CTF_SECTION[] = ".SUNW_ctf";
42 const char _CTF_NULLSTR[] = "";
43 
44 int _libctf_version = CTF_VERSION;	/* library client version */
45 int _libctf_debug = 0;			/* debugging messages enabled */
46 
47 static ushort_t
48 get_kind_v2(ushort_t info)
49 {
50 	return (CTF_INFO_KIND(info));
51 }
52 
53 static ushort_t
54 get_root_v2(ushort_t info)
55 {
56 	return (CTF_INFO_ISROOT(info));
57 }
58 
59 static ushort_t
60 get_vlen_v2(ushort_t info)
61 {
62 	return (CTF_INFO_VLEN(info));
63 }
64 
65 static const ctf_fileops_t ctf_fileops[] = {
66 	{ NULL, NULL },
67 	{ NULL, NULL },
68 	{ get_kind_v2, get_root_v2, get_vlen_v2 },
69 };
70 
71 /*
72  * Convert a 32-bit ELF symbol into GElf (Elf64) and return a pointer to it.
73  */
74 static Elf64_Sym *
75 sym_to_gelf(const Elf32_Sym *src, Elf64_Sym *dst)
76 {
77 	dst->st_name = src->st_name;
78 	dst->st_value = src->st_value;
79 	dst->st_size = src->st_size;
80 	dst->st_info = src->st_info;
81 	dst->st_other = src->st_other;
82 	dst->st_shndx = src->st_shndx;
83 
84 	return (dst);
85 }
86 
87 /*
88  * Initialize the symtab translation table by filling each entry with the
89  * offset of the CTF type or function data corresponding to each STT_FUNC or
90  * STT_OBJECT entry in the symbol table.
91  */
92 static int
93 init_symtab(ctf_file_t *fp, const ctf_header_t *hp,
94     const ctf_sect_t *sp, const ctf_sect_t *strp)
95 {
96 	const uchar_t *symp = sp->cts_data;
97 	uint_t *xp = fp->ctf_sxlate;
98 	uint_t *xend = xp + fp->ctf_nsyms;
99 
100 	uint_t objtoff = hp->cth_objtoff;
101 	uint_t funcoff = hp->cth_funcoff;
102 
103 	ushort_t info, vlen;
104 	Elf64_Sym sym, *gsp;
105 	const char *name;
106 
107 	/*
108 	 * The CTF data object and function type sections are ordered to match
109 	 * the relative order of the respective symbol types in the symtab.
110 	 * If no type information is available for a symbol table entry, a
111 	 * pad is inserted in the CTF section.  As a further optimization,
112 	 * anonymous or undefined symbols are omitted from the CTF data.
113 	 */
114 	for (; xp < xend; xp++, symp += sp->cts_entsize) {
115 		if (sp->cts_entsize == sizeof (Elf32_Sym))
116 			gsp = sym_to_gelf((Elf32_Sym *)(uintptr_t)symp, &sym);
117 		else
118 			gsp = (Elf64_Sym *)(uintptr_t)symp;
119 
120 		if (gsp->st_name < strp->cts_size)
121 			name = (const char *)strp->cts_data + gsp->st_name;
122 		else
123 			name = _CTF_NULLSTR;
124 
125 		if (gsp->st_name == 0 || gsp->st_shndx == SHN_UNDEF ||
126 		    strcmp(name, "_START_") == 0 ||
127 		    strcmp(name, "_END_") == 0) {
128 			*xp = -1u;
129 			continue;
130 		}
131 
132 		switch (ELF64_ST_TYPE(gsp->st_info)) {
133 		case STT_OBJECT:
134 			if (objtoff >= hp->cth_funcoff ||
135 			    (gsp->st_shndx == SHN_ABS && gsp->st_value == 0)) {
136 				*xp = -1u;
137 				break;
138 			}
139 
140 			*xp = objtoff;
141 			objtoff += sizeof (ushort_t);
142 			break;
143 
144 		case STT_FUNC:
145 			if (funcoff >= hp->cth_typeoff) {
146 				*xp = -1u;
147 				break;
148 			}
149 
150 			*xp = funcoff;
151 
152 			info = *(ushort_t *)((uintptr_t)fp->ctf_buf + funcoff);
153 			vlen = LCTF_INFO_VLEN(fp, info);
154 
155 			/*
156 			 * If we encounter a zero pad at the end, just skip it.
157 			 * Otherwise skip over the function and its return type
158 			 * (+2) and the argument list (vlen).
159 			 */
160 			if (LCTF_INFO_KIND(fp, info) == CTF_K_UNKNOWN &&
161 			    vlen == 0)
162 				funcoff += sizeof (ushort_t); /* skip pad */
163 			else
164 				funcoff += sizeof (ushort_t) * (vlen + 2);
165 			break;
166 
167 		default:
168 			*xp = -1u;
169 			break;
170 		}
171 	}
172 
173 	ctf_dprintf("loaded %lu symtab entries\n", fp->ctf_nsyms);
174 	return (0);
175 }
176 
177 /*
178  * Initialize the type ID translation table with the byte offset of each type,
179  * and initialize the hash tables of each named type.
180  */
181 static int
182 init_types(ctf_file_t *fp, const ctf_header_t *cth)
183 {
184 	/* LINTED - pointer alignment */
185 	const ctf_type_t *tbuf = (ctf_type_t *)(fp->ctf_buf + cth->cth_typeoff);
186 	/* LINTED - pointer alignment */
187 	const ctf_type_t *tend = (ctf_type_t *)(fp->ctf_buf + cth->cth_stroff);
188 
189 	ulong_t pop[CTF_K_MAX + 1] = { 0 };
190 	const ctf_type_t *tp;
191 	ctf_hash_t *hp;
192 	ushort_t id, dst;
193 	uint_t *xp;
194 
195 	/*
196 	 * We initially determine whether the container is a child or a parent
197 	 * based on the value of cth_parname.  To support containers that pre-
198 	 * date cth_parname, we also scan the types themselves for references
199 	 * to values in the range reserved for child types in our first pass.
200 	 */
201 	int child = cth->cth_parname != 0;
202 	int nlstructs = 0, nlunions = 0;
203 	int err;
204 
205 	/*
206 	 * We make two passes through the entire type section.  In this first
207 	 * pass, we count the number of each type and the total number of types.
208 	 */
209 	for (tp = tbuf; tp < tend; fp->ctf_typemax++) {
210 		ushort_t kind = LCTF_INFO_KIND(fp, tp->ctt_info);
211 		ulong_t vlen = LCTF_INFO_VLEN(fp, tp->ctt_info);
212 		ssize_t size, increment;
213 
214 		size_t vbytes;
215 		uint_t n;
216 
217 		(void) ctf_get_ctt_size(fp, tp, &size, &increment);
218 
219 		switch (kind) {
220 		case CTF_K_INTEGER:
221 		case CTF_K_FLOAT:
222 			vbytes = sizeof (uint_t);
223 			break;
224 		case CTF_K_ARRAY:
225 			vbytes = sizeof (ctf_array_t);
226 			break;
227 		case CTF_K_FUNCTION:
228 			vbytes = sizeof (ushort_t) * (vlen + (vlen & 1));
229 			break;
230 		case CTF_K_STRUCT:
231 		case CTF_K_UNION:
232 			if (fp->ctf_version == CTF_VERSION_1 ||
233 			    size < CTF_LSTRUCT_THRESH) {
234 				ctf_member_t *mp = (ctf_member_t *)
235 				    ((uintptr_t)tp + increment);
236 
237 				vbytes = sizeof (ctf_member_t) * vlen;
238 				for (n = vlen; n != 0; n--, mp++)
239 					child |= CTF_TYPE_ISCHILD(mp->ctm_type);
240 			} else {
241 				ctf_lmember_t *lmp = (ctf_lmember_t *)
242 				    ((uintptr_t)tp + increment);
243 
244 				vbytes = sizeof (ctf_lmember_t) * vlen;
245 				for (n = vlen; n != 0; n--, lmp++)
246 					child |=
247 					    CTF_TYPE_ISCHILD(lmp->ctlm_type);
248 			}
249 			break;
250 		case CTF_K_ENUM:
251 			vbytes = sizeof (ctf_enum_t) * vlen;
252 			break;
253 		case CTF_K_FORWARD:
254 			/*
255 			 * For forward declarations, ctt_type is the CTF_K_*
256 			 * kind for the tag, so bump that population count too.
257 			 * If ctt_type is unknown, treat the tag as a struct.
258 			 */
259 			if (tp->ctt_type == CTF_K_UNKNOWN ||
260 			    tp->ctt_type >= CTF_K_MAX)
261 				pop[CTF_K_STRUCT]++;
262 			else
263 				pop[tp->ctt_type]++;
264 			/*FALLTHRU*/
265 		case CTF_K_UNKNOWN:
266 			vbytes = 0;
267 			break;
268 		case CTF_K_POINTER:
269 		case CTF_K_TYPEDEF:
270 		case CTF_K_VOLATILE:
271 		case CTF_K_CONST:
272 		case CTF_K_RESTRICT:
273 			child |= CTF_TYPE_ISCHILD(tp->ctt_type);
274 			vbytes = 0;
275 			break;
276 		default:
277 			ctf_dprintf("detected invalid CTF kind -- %u\n", kind);
278 			return (ECTF_CORRUPT);
279 		}
280 		tp = (ctf_type_t *)((uintptr_t)tp + increment + vbytes);
281 		pop[kind]++;
282 	}
283 
284 	/*
285 	 * If we detected a reference to a child type ID, then we know this
286 	 * container is a child and may have a parent's types imported later.
287 	 */
288 	if (child) {
289 		ctf_dprintf("CTF container %p is a child\n", (void *)fp);
290 		fp->ctf_flags |= LCTF_CHILD;
291 	} else
292 		ctf_dprintf("CTF container %p is a parent\n", (void *)fp);
293 
294 	/*
295 	 * Now that we've counted up the number of each type, we can allocate
296 	 * the hash tables, type translation table, and pointer table.
297 	 */
298 	if ((err = ctf_hash_create(&fp->ctf_structs, pop[CTF_K_STRUCT])) != 0)
299 		return (err);
300 
301 	if ((err = ctf_hash_create(&fp->ctf_unions, pop[CTF_K_UNION])) != 0)
302 		return (err);
303 
304 	if ((err = ctf_hash_create(&fp->ctf_enums, pop[CTF_K_ENUM])) != 0)
305 		return (err);
306 
307 	if ((err = ctf_hash_create(&fp->ctf_names,
308 	    pop[CTF_K_INTEGER] + pop[CTF_K_FLOAT] + pop[CTF_K_FUNCTION] +
309 	    pop[CTF_K_TYPEDEF] + pop[CTF_K_POINTER] + pop[CTF_K_VOLATILE] +
310 	    pop[CTF_K_CONST] + pop[CTF_K_RESTRICT])) != 0)
311 		return (err);
312 
313 	fp->ctf_txlate = ctf_alloc(sizeof (uint_t) * (fp->ctf_typemax + 1));
314 	fp->ctf_ptrtab = ctf_alloc(sizeof (ushort_t) * (fp->ctf_typemax + 1));
315 
316 	if (fp->ctf_txlate == NULL || fp->ctf_ptrtab == NULL)
317 		return (EAGAIN); /* memory allocation failed */
318 
319 	xp = fp->ctf_txlate;
320 	*xp++ = 0; /* type id 0 is used as a sentinel value */
321 
322 	bzero(fp->ctf_txlate, sizeof (uint_t) * (fp->ctf_typemax + 1));
323 	bzero(fp->ctf_ptrtab, sizeof (ushort_t) * (fp->ctf_typemax + 1));
324 
325 	/*
326 	 * In the second pass through the types, we fill in each entry of the
327 	 * type and pointer tables and add names to the appropriate hashes.
328 	 */
329 	for (id = 1, tp = tbuf; tp < tend; xp++, id++) {
330 		ushort_t kind = LCTF_INFO_KIND(fp, tp->ctt_info);
331 		ulong_t vlen = LCTF_INFO_VLEN(fp, tp->ctt_info);
332 		ssize_t size, increment;
333 
334 		const char *name;
335 		size_t vbytes;
336 		ctf_helem_t *hep;
337 		ctf_encoding_t cte;
338 
339 		(void) ctf_get_ctt_size(fp, tp, &size, &increment);
340 		name = ctf_strptr(fp, tp->ctt_name);
341 
342 		switch (kind) {
343 		case CTF_K_INTEGER:
344 		case CTF_K_FLOAT:
345 			/*
346 			 * Only insert a new integer base type definition if
347 			 * this type name has not been defined yet.  We re-use
348 			 * the names with different encodings for bit-fields.
349 			 */
350 			if ((hep = ctf_hash_lookup(&fp->ctf_names, fp,
351 			    name, strlen(name))) == NULL) {
352 				err = ctf_hash_insert(&fp->ctf_names, fp,
353 				    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
354 				if (err != 0 && err != ECTF_STRTAB)
355 					return (err);
356 			} else if (ctf_type_encoding(fp, hep->h_type,
357 			    &cte) == 0 && cte.cte_bits == 0) {
358 				/*
359 				 * Work-around SOS8 stabs bug: replace existing
360 				 * intrinsic w/ same name if it was zero bits.
361 				 */
362 				hep->h_type = CTF_INDEX_TO_TYPE(id, child);
363 			}
364 			vbytes = sizeof (uint_t);
365 			break;
366 
367 		case CTF_K_ARRAY:
368 			vbytes = sizeof (ctf_array_t);
369 			break;
370 
371 		case CTF_K_FUNCTION:
372 			err = ctf_hash_insert(&fp->ctf_names, fp,
373 			    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
374 			if (err != 0 && err != ECTF_STRTAB)
375 				return (err);
376 			vbytes = sizeof (ushort_t) * (vlen + (vlen & 1));
377 			break;
378 
379 		case CTF_K_STRUCT:
380 			err = ctf_hash_define(&fp->ctf_structs, fp,
381 			    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
382 
383 			if (err != 0 && err != ECTF_STRTAB)
384 				return (err);
385 
386 			if (fp->ctf_version == CTF_VERSION_1 ||
387 			    size < CTF_LSTRUCT_THRESH)
388 				vbytes = sizeof (ctf_member_t) * vlen;
389 			else {
390 				vbytes = sizeof (ctf_lmember_t) * vlen;
391 				nlstructs++;
392 			}
393 			break;
394 
395 		case CTF_K_UNION:
396 			err = ctf_hash_define(&fp->ctf_unions, fp,
397 			    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
398 
399 			if (err != 0 && err != ECTF_STRTAB)
400 				return (err);
401 
402 			if (fp->ctf_version == CTF_VERSION_1 ||
403 			    size < CTF_LSTRUCT_THRESH)
404 				vbytes = sizeof (ctf_member_t) * vlen;
405 			else {
406 				vbytes = sizeof (ctf_lmember_t) * vlen;
407 				nlunions++;
408 			}
409 			break;
410 
411 		case CTF_K_ENUM:
412 			err = ctf_hash_define(&fp->ctf_enums, fp,
413 			    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
414 
415 			if (err != 0 && err != ECTF_STRTAB)
416 				return (err);
417 
418 			vbytes = sizeof (ctf_enum_t) * vlen;
419 			break;
420 
421 		case CTF_K_TYPEDEF:
422 			err = ctf_hash_insert(&fp->ctf_names, fp,
423 			    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
424 			if (err != 0 && err != ECTF_STRTAB)
425 				return (err);
426 			vbytes = 0;
427 			break;
428 
429 		case CTF_K_FORWARD:
430 			/*
431 			 * Only insert forward tags into the given hash if the
432 			 * type or tag name is not already present.
433 			 */
434 			switch (tp->ctt_type) {
435 			case CTF_K_STRUCT:
436 				hp = &fp->ctf_structs;
437 				break;
438 			case CTF_K_UNION:
439 				hp = &fp->ctf_unions;
440 				break;
441 			case CTF_K_ENUM:
442 				hp = &fp->ctf_enums;
443 				break;
444 			default:
445 				hp = &fp->ctf_structs;
446 			}
447 
448 			if (ctf_hash_lookup(hp, fp,
449 			    name, strlen(name)) == NULL) {
450 				err = ctf_hash_insert(hp, fp,
451 				    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
452 				if (err != 0 && err != ECTF_STRTAB)
453 					return (err);
454 			}
455 			vbytes = 0;
456 			break;
457 
458 		case CTF_K_POINTER:
459 			/*
460 			 * If the type referenced by the pointer is in this CTF
461 			 * container, then store the index of the pointer type
462 			 * in fp->ctf_ptrtab[ index of referenced type ].
463 			 */
464 			if (CTF_TYPE_ISCHILD(tp->ctt_type) == child &&
465 			    CTF_TYPE_TO_INDEX(tp->ctt_type) <= fp->ctf_typemax)
466 				fp->ctf_ptrtab[
467 				    CTF_TYPE_TO_INDEX(tp->ctt_type)] = id;
468 			/*FALLTHRU*/
469 
470 		case CTF_K_VOLATILE:
471 		case CTF_K_CONST:
472 		case CTF_K_RESTRICT:
473 			err = ctf_hash_insert(&fp->ctf_names, fp,
474 			    CTF_INDEX_TO_TYPE(id, child), tp->ctt_name);
475 			if (err != 0 && err != ECTF_STRTAB)
476 				return (err);
477 			/*FALLTHRU*/
478 
479 		default:
480 			vbytes = 0;
481 			break;
482 		}
483 
484 		*xp = (uint_t)((uintptr_t)tp - (uintptr_t)fp->ctf_buf);
485 		tp = (ctf_type_t *)((uintptr_t)tp + increment + vbytes);
486 	}
487 
488 	ctf_dprintf("%lu total types processed\n", fp->ctf_typemax);
489 	ctf_dprintf("%u enum names hashed\n", ctf_hash_size(&fp->ctf_enums));
490 	ctf_dprintf("%u struct names hashed (%d long)\n",
491 	    ctf_hash_size(&fp->ctf_structs), nlstructs);
492 	ctf_dprintf("%u union names hashed (%d long)\n",
493 	    ctf_hash_size(&fp->ctf_unions), nlunions);
494 	ctf_dprintf("%u base type names hashed\n",
495 	    ctf_hash_size(&fp->ctf_names));
496 
497 	/*
498 	 * Make an additional pass through the pointer table to find pointers
499 	 * that point to anonymous typedef nodes.  If we find one, modify the
500 	 * pointer table so that the pointer is also known to point to the
501 	 * node that is referenced by the anonymous typedef node.
502 	 */
503 	for (id = 1; id <= fp->ctf_typemax; id++) {
504 		if ((dst = fp->ctf_ptrtab[id]) != 0) {
505 			tp = LCTF_INDEX_TO_TYPEPTR(fp, id);
506 
507 			if (LCTF_INFO_KIND(fp, tp->ctt_info) == CTF_K_TYPEDEF &&
508 			    strcmp(ctf_strptr(fp, tp->ctt_name), "") == 0 &&
509 			    CTF_TYPE_ISCHILD(tp->ctt_type) == child &&
510 			    CTF_TYPE_TO_INDEX(tp->ctt_type) <= fp->ctf_typemax)
511 				fp->ctf_ptrtab[
512 				    CTF_TYPE_TO_INDEX(tp->ctt_type)] = dst;
513 		}
514 	}
515 
516 	return (0);
517 }
518 
519 /*
520  * Decode the specified CTF buffer and optional symbol table and create a new
521  * CTF container representing the symbolic debugging information.  This code
522  * can be used directly by the debugger, or it can be used as the engine for
523  * ctf_fdopen() or ctf_open(), below.
524  */
525 ctf_file_t *
526 ctf_bufopen(const ctf_sect_t *ctfsect, const ctf_sect_t *symsect,
527     const ctf_sect_t *strsect, int *errp)
528 {
529 	const ctf_preamble_t *pp;
530 	ctf_header_t hp;
531 	ctf_file_t *fp;
532 	void *buf, *base;
533 	size_t size, hdrsz;
534 	int err;
535 
536 	if (ctfsect == NULL || ((symsect == NULL) != (strsect == NULL)))
537 		return (ctf_set_open_errno(errp, EINVAL));
538 
539 	if (symsect != NULL && symsect->cts_entsize != sizeof (Elf32_Sym) &&
540 	    symsect->cts_entsize != sizeof (Elf64_Sym))
541 		return (ctf_set_open_errno(errp, ECTF_SYMTAB));
542 
543 	if (symsect != NULL && symsect->cts_data == NULL)
544 		return (ctf_set_open_errno(errp, ECTF_SYMBAD));
545 
546 	if (strsect != NULL && strsect->cts_data == NULL)
547 		return (ctf_set_open_errno(errp, ECTF_STRBAD));
548 
549 	if (ctfsect->cts_size < sizeof (ctf_preamble_t))
550 		return (ctf_set_open_errno(errp, ECTF_NOCTFBUF));
551 
552 	pp = (const ctf_preamble_t *)ctfsect->cts_data;
553 
554 	ctf_dprintf("ctf_bufopen: magic=0x%x version=%u\n",
555 	    pp->ctp_magic, pp->ctp_version);
556 
557 	/*
558 	 * Validate each part of the CTF header (either V1 or V2).
559 	 * First, we validate the preamble (common to all versions).  At that
560 	 * point, we know specific header version, and can validate the
561 	 * version-specific parts including section offsets and alignments.
562 	 */
563 	if (pp->ctp_magic != CTF_MAGIC)
564 		return (ctf_set_open_errno(errp, ECTF_NOCTFBUF));
565 
566 	if (pp->ctp_version == CTF_VERSION_2) {
567 		if (ctfsect->cts_size < sizeof (ctf_header_t))
568 			return (ctf_set_open_errno(errp, ECTF_NOCTFBUF));
569 
570 		bcopy(ctfsect->cts_data, &hp, sizeof (hp));
571 		hdrsz = sizeof (ctf_header_t);
572 
573 	} else
574 		return (ctf_set_open_errno(errp, ECTF_CTFVERS));
575 
576 	size = hp.cth_stroff + hp.cth_strlen;
577 
578 	ctf_dprintf("ctf_bufopen: uncompressed size=%lu\n", (ulong_t)size);
579 
580 	if (hp.cth_lbloff > size || hp.cth_objtoff > size ||
581 	    hp.cth_funcoff > size || hp.cth_typeoff > size ||
582 	    hp.cth_stroff > size)
583 		return (ctf_set_open_errno(errp, ECTF_CORRUPT));
584 
585 	if (hp.cth_lbloff > hp.cth_objtoff ||
586 	    hp.cth_objtoff > hp.cth_funcoff ||
587 	    hp.cth_funcoff > hp.cth_typeoff ||
588 	    hp.cth_typeoff > hp.cth_stroff)
589 		return (ctf_set_open_errno(errp, ECTF_CORRUPT));
590 
591 	if ((hp.cth_lbloff & 3) || (hp.cth_objtoff & 1) ||
592 	    (hp.cth_funcoff & 1) || (hp.cth_typeoff & 3))
593 		return (ctf_set_open_errno(errp, ECTF_CORRUPT));
594 
595 	/*
596 	 * Once everything is determined to be valid, attempt to decompress
597 	 * the CTF data buffer if it is compressed.  Otherwise we just put
598 	 * the data section's buffer pointer into ctf_buf, below.
599 	 */
600 	if (hp.cth_flags & CTF_F_COMPRESS) {
601 		size_t srclen, dstlen;
602 		const void *src;
603 		int rc = Z_OK;
604 
605 		if (ctf_zopen(errp) == NULL)
606 			return (NULL); /* errp is set for us */
607 
608 		if ((base = ctf_data_alloc(size + hdrsz)) == MAP_FAILED)
609 			return (ctf_set_open_errno(errp, ECTF_ZALLOC));
610 
611 		bcopy(ctfsect->cts_data, base, hdrsz);
612 		((ctf_preamble_t *)base)->ctp_flags &= ~CTF_F_COMPRESS;
613 		buf = (uchar_t *)base + hdrsz;
614 
615 		src = (uchar_t *)ctfsect->cts_data + hdrsz;
616 		srclen = ctfsect->cts_size - hdrsz;
617 		dstlen = size;
618 
619 		if ((rc = z_uncompress(buf, &dstlen, src, srclen)) != Z_OK) {
620 			ctf_dprintf("zlib inflate err: %s\n", z_strerror(rc));
621 			ctf_data_free(base, size + hdrsz);
622 			return (ctf_set_open_errno(errp, ECTF_DECOMPRESS));
623 		}
624 
625 		if (dstlen != size) {
626 			ctf_dprintf("zlib inflate short -- got %lu of %lu "
627 			    "bytes\n", (ulong_t)dstlen, (ulong_t)size);
628 			ctf_data_free(base, size + hdrsz);
629 			return (ctf_set_open_errno(errp, ECTF_CORRUPT));
630 		}
631 
632 		ctf_data_protect(base, size + hdrsz);
633 
634 	} else {
635 		base = (void *)ctfsect->cts_data;
636 		buf = (uchar_t *)base + hdrsz;
637 	}
638 
639 	/*
640 	 * Once we have uncompressed and validated the CTF data buffer, we can
641 	 * proceed with allocating a ctf_file_t and initializing it.
642 	 */
643 	if ((fp = ctf_alloc(sizeof (ctf_file_t))) == NULL)
644 		return (ctf_set_open_errno(errp, EAGAIN));
645 
646 	bzero(fp, sizeof (ctf_file_t));
647 	fp->ctf_version = hp.cth_version;
648 	fp->ctf_fileops = &ctf_fileops[hp.cth_version];
649 	bcopy(ctfsect, &fp->ctf_data, sizeof (ctf_sect_t));
650 
651 	if (symsect != NULL) {
652 		bcopy(symsect, &fp->ctf_symtab, sizeof (ctf_sect_t));
653 		bcopy(strsect, &fp->ctf_strtab, sizeof (ctf_sect_t));
654 	}
655 
656 	if (fp->ctf_data.cts_name != NULL)
657 		fp->ctf_data.cts_name = ctf_strdup(fp->ctf_data.cts_name);
658 	if (fp->ctf_symtab.cts_name != NULL)
659 		fp->ctf_symtab.cts_name = ctf_strdup(fp->ctf_symtab.cts_name);
660 	if (fp->ctf_strtab.cts_name != NULL)
661 		fp->ctf_strtab.cts_name = ctf_strdup(fp->ctf_strtab.cts_name);
662 
663 	if (fp->ctf_data.cts_name == NULL)
664 		fp->ctf_data.cts_name = _CTF_NULLSTR;
665 	if (fp->ctf_symtab.cts_name == NULL)
666 		fp->ctf_symtab.cts_name = _CTF_NULLSTR;
667 	if (fp->ctf_strtab.cts_name == NULL)
668 		fp->ctf_strtab.cts_name = _CTF_NULLSTR;
669 
670 	fp->ctf_str[CTF_STRTAB_0].cts_strs = (const char *)buf + hp.cth_stroff;
671 	fp->ctf_str[CTF_STRTAB_0].cts_len = hp.cth_strlen;
672 
673 	if (strsect != NULL) {
674 		fp->ctf_str[CTF_STRTAB_1].cts_strs = strsect->cts_data;
675 		fp->ctf_str[CTF_STRTAB_1].cts_len = strsect->cts_size;
676 	}
677 
678 	fp->ctf_base = base;
679 	fp->ctf_buf = buf;
680 	fp->ctf_size = size + hdrsz;
681 
682 	/*
683 	 * If we have a parent container name and label, store the relocated
684 	 * string pointers in the CTF container for easy access later.
685 	 */
686 	if (hp.cth_parlabel != 0)
687 		fp->ctf_parlabel = ctf_strptr(fp, hp.cth_parlabel);
688 	if (hp.cth_parname != 0)
689 		fp->ctf_parname = ctf_strptr(fp, hp.cth_parname);
690 
691 	ctf_dprintf("ctf_bufopen: parent name %s (label %s)\n",
692 	    fp->ctf_parname ? fp->ctf_parname : "<NULL>",
693 	    fp->ctf_parlabel ? fp->ctf_parlabel : "<NULL>");
694 
695 	/*
696 	 * If we have a symbol table section, allocate and initialize
697 	 * the symtab translation table, pointed to by ctf_sxlate.
698 	 */
699 	if (symsect != NULL) {
700 		fp->ctf_nsyms = symsect->cts_size / symsect->cts_entsize;
701 		fp->ctf_sxlate = ctf_alloc(fp->ctf_nsyms * sizeof (uint_t));
702 
703 		if (fp->ctf_sxlate == NULL) {
704 			(void) ctf_set_open_errno(errp, EAGAIN);
705 			goto bad;
706 		}
707 
708 		if ((err = init_symtab(fp, &hp, symsect, strsect)) != 0) {
709 			(void) ctf_set_open_errno(errp, err);
710 			goto bad;
711 		}
712 	}
713 
714 	if ((err = init_types(fp, &hp)) != 0) {
715 		(void) ctf_set_open_errno(errp, err);
716 		goto bad;
717 	}
718 
719 	/*
720 	 * Initialize the ctf_lookup_by_name top-level dictionary.  We keep an
721 	 * array of type name prefixes and the corresponding ctf_hash to use.
722 	 * NOTE: This code must be kept in sync with the code in ctf_update().
723 	 */
724 	fp->ctf_lookups[0].ctl_prefix = "struct";
725 	fp->ctf_lookups[0].ctl_len = strlen(fp->ctf_lookups[0].ctl_prefix);
726 	fp->ctf_lookups[0].ctl_hash = &fp->ctf_structs;
727 	fp->ctf_lookups[1].ctl_prefix = "union";
728 	fp->ctf_lookups[1].ctl_len = strlen(fp->ctf_lookups[1].ctl_prefix);
729 	fp->ctf_lookups[1].ctl_hash = &fp->ctf_unions;
730 	fp->ctf_lookups[2].ctl_prefix = "enum";
731 	fp->ctf_lookups[2].ctl_len = strlen(fp->ctf_lookups[2].ctl_prefix);
732 	fp->ctf_lookups[2].ctl_hash = &fp->ctf_enums;
733 	fp->ctf_lookups[3].ctl_prefix = _CTF_NULLSTR;
734 	fp->ctf_lookups[3].ctl_len = strlen(fp->ctf_lookups[3].ctl_prefix);
735 	fp->ctf_lookups[3].ctl_hash = &fp->ctf_names;
736 	fp->ctf_lookups[4].ctl_prefix = NULL;
737 	fp->ctf_lookups[4].ctl_len = 0;
738 	fp->ctf_lookups[4].ctl_hash = NULL;
739 
740 	if (symsect != NULL) {
741 		if (symsect->cts_entsize == sizeof (Elf64_Sym))
742 			(void) ctf_setmodel(fp, CTF_MODEL_LP64);
743 		else
744 			(void) ctf_setmodel(fp, CTF_MODEL_ILP32);
745 	} else
746 		(void) ctf_setmodel(fp, CTF_MODEL_NATIVE);
747 
748 	fp->ctf_refcnt = 1;
749 	return (fp);
750 
751 bad:
752 	ctf_close(fp);
753 	return (NULL);
754 }
755 
756 /*
757  * Dupliate a ctf_file_t and its underlying section information into a new
758  * container. This works by copying the three ctf_sect_t's of the original
759  * container if they exist and passing those into ctf_bufopen. To copy those, we
760  * mmap anonymous memory with ctf_data_alloc and bcopy the data across. It's not
761  * the cheapest thing, but it's what we've got.
762  */
763 ctf_file_t *
764 ctf_dup(ctf_file_t *ofp)
765 {
766 	ctf_file_t *fp;
767 	ctf_sect_t ctfsect, symsect, strsect;
768 	ctf_sect_t *ctp, *symp, *strp;
769 	void *cbuf, *symbuf, *strbuf;
770 	int err;
771 
772 	cbuf = symbuf = strbuf = NULL;
773 	/*
774 	 * The ctfsect isn't allowed to not exist, but the symbol and string
775 	 * section might not. We only need to copy the data of the section, not
776 	 * the name, as ctf_bufopen will take care of that.
777 	 */
778 	bcopy(&ofp->ctf_data, &ctfsect, sizeof (ctf_sect_t));
779 	cbuf = ctf_data_alloc(ctfsect.cts_size);
780 	if (cbuf == NULL) {
781 		(void) ctf_set_errno(ofp, ECTF_MMAP);
782 		return (NULL);
783 	}
784 
785 	bcopy(ctfsect.cts_data, cbuf, ctfsect.cts_size);
786 	ctf_data_protect(cbuf, ctfsect.cts_size);
787 	ctfsect.cts_data = cbuf;
788 	ctfsect.cts_offset = 0;
789 	ctp = &ctfsect;
790 
791 	if (ofp->ctf_symtab.cts_data != NULL) {
792 		bcopy(&ofp->ctf_symtab, &symsect, sizeof (ctf_sect_t));
793 		symbuf = ctf_data_alloc(symsect.cts_size);
794 		if (symbuf == NULL) {
795 			(void) ctf_set_errno(ofp, ECTF_MMAP);
796 			goto err;
797 		}
798 		bcopy(symsect.cts_data, symbuf, symsect.cts_size);
799 		ctf_data_protect(symbuf, symsect.cts_size);
800 		symsect.cts_data = symbuf;
801 		symsect.cts_offset = 0;
802 		symp = &symsect;
803 	} else {
804 		symp = NULL;
805 	}
806 
807 	if (ofp->ctf_strtab.cts_data != NULL) {
808 		bcopy(&ofp->ctf_strtab, &strsect, sizeof (ctf_sect_t));
809 		strbuf = ctf_data_alloc(strsect.cts_size);
810 		if (strbuf == NULL) {
811 			(void) ctf_set_errno(ofp, ECTF_MMAP);
812 			goto err;
813 		}
814 		bcopy(strsect.cts_data, strbuf, strsect.cts_size);
815 		ctf_data_protect(strbuf, strsect.cts_size);
816 		strsect.cts_data = strbuf;
817 		strsect.cts_offset = 0;
818 		strp = &strsect;
819 	} else {
820 		strp = NULL;
821 	}
822 
823 	fp = ctf_bufopen(ctp, symp, strp, &err);
824 	if (fp == NULL) {
825 		(void) ctf_set_errno(ofp, err);
826 		goto err;
827 	}
828 
829 	fp->ctf_flags |= LCTF_MMAP;
830 
831 	return (fp);
832 
833 err:
834 	ctf_data_free(cbuf, ctfsect.cts_size);
835 	if (symbuf != NULL)
836 		ctf_data_free(symbuf, symsect.cts_size);
837 	if (strbuf != NULL)
838 		ctf_data_free(strbuf, strsect.cts_size);
839 	return (NULL);
840 }
841 
842 /*
843  * Close the specified CTF container and free associated data structures.  Note
844  * that ctf_close() is a reference counted operation: if the specified file is
845  * the parent of other active containers, its reference count will be greater
846  * than one and it will be freed later when no active children exist.
847  */
848 void
849 ctf_close(ctf_file_t *fp)
850 {
851 	ctf_dtdef_t *dtd, *ntd;
852 
853 	if (fp == NULL)
854 		return; /* allow ctf_close(NULL) to simplify caller code */
855 
856 	ctf_dprintf("ctf_close(%p) refcnt=%u\n", (void *)fp, fp->ctf_refcnt);
857 
858 	if (fp->ctf_refcnt > 1) {
859 		fp->ctf_refcnt--;
860 		return;
861 	}
862 
863 	if (fp->ctf_parent != NULL)
864 		ctf_close(fp->ctf_parent);
865 
866 	/*
867 	 * Note, to work properly with reference counting on the dynamic
868 	 * section, we must delete the list in reverse.
869 	 */
870 	for (dtd = ctf_list_prev(&fp->ctf_dtdefs); dtd != NULL; dtd = ntd) {
871 		ntd = ctf_list_prev(dtd);
872 		ctf_dtd_delete(fp, dtd);
873 	}
874 
875 	ctf_free(fp->ctf_dthash, fp->ctf_dthashlen * sizeof (ctf_dtdef_t *));
876 
877 	if (fp->ctf_flags & LCTF_MMAP) {
878 		if (fp->ctf_data.cts_data != NULL)
879 			ctf_sect_munmap(&fp->ctf_data);
880 		if (fp->ctf_symtab.cts_data != NULL)
881 			ctf_sect_munmap(&fp->ctf_symtab);
882 		if (fp->ctf_strtab.cts_data != NULL)
883 			ctf_sect_munmap(&fp->ctf_strtab);
884 	}
885 
886 	if (fp->ctf_data.cts_name != _CTF_NULLSTR &&
887 	    fp->ctf_data.cts_name != NULL) {
888 		ctf_free((char *)fp->ctf_data.cts_name,
889 		    strlen(fp->ctf_data.cts_name) + 1);
890 	}
891 
892 	if (fp->ctf_symtab.cts_name != _CTF_NULLSTR &&
893 	    fp->ctf_symtab.cts_name != NULL) {
894 		ctf_free((char *)fp->ctf_symtab.cts_name,
895 		    strlen(fp->ctf_symtab.cts_name) + 1);
896 	}
897 
898 	if (fp->ctf_strtab.cts_name != _CTF_NULLSTR &&
899 	    fp->ctf_strtab.cts_name != NULL) {
900 		ctf_free((char *)fp->ctf_strtab.cts_name,
901 		    strlen(fp->ctf_strtab.cts_name) + 1);
902 	}
903 
904 	if (fp->ctf_base != fp->ctf_data.cts_data && fp->ctf_base != NULL)
905 		ctf_data_free((void *)fp->ctf_base, fp->ctf_size);
906 
907 	if (fp->ctf_sxlate != NULL)
908 		ctf_free(fp->ctf_sxlate, sizeof (uint_t) * fp->ctf_nsyms);
909 
910 	if (fp->ctf_txlate != NULL) {
911 		ctf_free(fp->ctf_txlate,
912 		    sizeof (uint_t) * (fp->ctf_typemax + 1));
913 	}
914 
915 	if (fp->ctf_ptrtab != NULL) {
916 		ctf_free(fp->ctf_ptrtab,
917 		    sizeof (ushort_t) * (fp->ctf_typemax + 1));
918 	}
919 
920 	ctf_hash_destroy(&fp->ctf_structs);
921 	ctf_hash_destroy(&fp->ctf_unions);
922 	ctf_hash_destroy(&fp->ctf_enums);
923 	ctf_hash_destroy(&fp->ctf_names);
924 
925 	ctf_free(fp, sizeof (ctf_file_t));
926 }
927 
928 /*
929  * Return the CTF handle for the parent CTF container, if one exists.
930  * Otherwise return NULL to indicate this container has no imported parent.
931  */
932 ctf_file_t *
933 ctf_parent_file(ctf_file_t *fp)
934 {
935 	return (fp->ctf_parent);
936 }
937 
938 /*
939  * Return the name of the parent CTF container, if one exists.  Otherwise
940  * return NULL to indicate this container is a root container.
941  */
942 const char *
943 ctf_parent_name(ctf_file_t *fp)
944 {
945 	return (fp->ctf_parname);
946 }
947 
948 /*
949  * Import the types from the specified parent container by storing a pointer
950  * to it in ctf_parent and incrementing its reference count.  Only one parent
951  * is allowed: if a parent already exists, it is replaced by the new parent.
952  */
953 int
954 ctf_import(ctf_file_t *fp, ctf_file_t *pfp)
955 {
956 	if (fp == NULL || fp == pfp || (pfp != NULL && pfp->ctf_refcnt == 0))
957 		return (ctf_set_errno(fp, EINVAL));
958 
959 	if (pfp != NULL && pfp->ctf_dmodel != fp->ctf_dmodel)
960 		return (ctf_set_errno(fp, ECTF_DMODEL));
961 
962 	if (fp->ctf_parent != NULL)
963 		ctf_close(fp->ctf_parent);
964 
965 	if (pfp != NULL) {
966 		fp->ctf_flags |= LCTF_CHILD;
967 		pfp->ctf_refcnt++;
968 	}
969 
970 	fp->ctf_parent = pfp;
971 	return (0);
972 }
973 
974 /*
975  * Set the data model constant for the CTF container.
976  */
977 int
978 ctf_setmodel(ctf_file_t *fp, int model)
979 {
980 	const ctf_dmodel_t *dp;
981 
982 	for (dp = _libctf_models; dp->ctd_name != NULL; dp++) {
983 		if (dp->ctd_code == model) {
984 			fp->ctf_dmodel = dp;
985 			return (0);
986 		}
987 	}
988 
989 	return (ctf_set_errno(fp, EINVAL));
990 }
991 
992 /*
993  * Return the data model constant for the CTF container.
994  */
995 int
996 ctf_getmodel(ctf_file_t *fp)
997 {
998 	return (fp->ctf_dmodel->ctd_code);
999 }
1000 
1001 void
1002 ctf_setspecific(ctf_file_t *fp, void *data)
1003 {
1004 	fp->ctf_specific = data;
1005 }
1006 
1007 void *
1008 ctf_getspecific(ctf_file_t *fp)
1009 {
1010 	return (fp->ctf_specific);
1011 }
1012