xref: /netbsd-src/external/cddl/osnet/dist/tools/ctf/cvt/output.c (revision a5847cc334d9a7029f6352b847e9e8d71a0f9e0c)
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 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * Routines for preparing tdata trees for conversion into CTF data, and
30  * for placing the resulting data into an output file.
31  */
32 
33 #if HAVE_NBTOOL_CONFIG_H
34 # include "nbtool_config.h"
35 #endif
36 
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <strings.h>
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 #include <fcntl.h>
43 #include <libelf.h>
44 #include <gelf.h>
45 #include <unistd.h>
46 
47 #include "ctftools.h"
48 #include "list.h"
49 #include "memory.h"
50 #include "traverse.h"
51 #include "symbol.h"
52 
53 typedef struct iidesc_match {
54 	int iim_fuzzy;
55 	iidesc_t *iim_ret;
56 	char *iim_name;
57 	char *iim_file;
58 	uchar_t iim_bind;
59 } iidesc_match_t;
60 
61 static int
62 burst_iitypes(void *data, void *arg)
63 {
64 	iidesc_t *ii = data;
65 	iiburst_t *iiburst = arg;
66 
67 	switch (ii->ii_type) {
68 	case II_GFUN:
69 	case II_SFUN:
70 	case II_GVAR:
71 	case II_SVAR:
72 		if (!(ii->ii_flags & IIDESC_F_USED))
73 			return (0);
74 		break;
75 	default:
76 		break;
77 	}
78 
79 	ii->ii_dtype->t_flags |= TDESC_F_ISROOT;
80 	(void) iitraverse_td(ii, iiburst->iib_tdtd);
81 	return (1);
82 }
83 
84 /*ARGSUSED1*/
85 static int
86 save_type_by_id(tdesc_t *tdp, tdesc_t **tdpp __unused, void *private)
87 {
88 	iiburst_t *iiburst = private;
89 
90 	/*
91 	 * Doing this on every node is horribly inefficient, but given that
92 	 * we may be suppressing some types, we can't trust nextid in the
93 	 * tdata_t.
94 	 */
95 	if (tdp->t_id > iiburst->iib_maxtypeid)
96 		iiburst->iib_maxtypeid = tdp->t_id;
97 
98 	slist_add(&iiburst->iib_types, tdp, tdesc_idcmp);
99 
100 	return (1);
101 }
102 
103 static tdtrav_cb_f burst_types_cbs[] = {
104 	NULL,
105 	save_type_by_id,	/* intrinsic */
106 	save_type_by_id,	/* pointer */
107 	save_type_by_id,	/* array */
108 	save_type_by_id,	/* function */
109 	save_type_by_id,	/* struct */
110 	save_type_by_id,	/* union */
111 	save_type_by_id,	/* enum */
112 	save_type_by_id,	/* forward */
113 	save_type_by_id,	/* typedef */
114 	tdtrav_assert,		/* typedef_unres */
115 	save_type_by_id,	/* volatile */
116 	save_type_by_id,	/* const */
117 	save_type_by_id		/* restrict */
118 };
119 
120 
121 static iiburst_t *
122 iiburst_new(tdata_t *td, int max)
123 {
124 	iiburst_t *iiburst = xcalloc(sizeof (iiburst_t));
125 	iiburst->iib_td = td;
126 	iiburst->iib_funcs = xcalloc(sizeof (iidesc_t *) * max);
127 	iiburst->iib_nfuncs = 0;
128 	iiburst->iib_objts = xcalloc(sizeof (iidesc_t *) * max);
129 	iiburst->iib_nobjts = 0;
130 	return (iiburst);
131 }
132 
133 static void
134 iiburst_types(iiburst_t *iiburst)
135 {
136 	tdtrav_data_t tdtd;
137 
138 	tdtrav_init(&tdtd, &iiburst->iib_td->td_curvgen, NULL, burst_types_cbs,
139 	    NULL, (void *)iiburst);
140 
141 	iiburst->iib_tdtd = &tdtd;
142 
143 	(void) hash_iter(iiburst->iib_td->td_iihash, burst_iitypes, iiburst);
144 }
145 
146 static void
147 iiburst_free(iiburst_t *iiburst)
148 {
149 	free(iiburst->iib_funcs);
150 	free(iiburst->iib_objts);
151 	list_free(iiburst->iib_types, NULL, NULL);
152 	free(iiburst);
153 }
154 
155 /*
156  * See if this iidesc matches the ELF symbol data we pass in.
157  *
158  * A fuzzy match is where we have a local symbol matching the name of a
159  * global type description. This is common when a mapfile is used for a
160  * DSO, but we don't accept it by default.
161  *
162  * A weak fuzzy match is when a weak symbol was resolved and matched to
163  * a global type description.
164  */
165 static int
166 matching_iidesc(void *arg1, void *arg2)
167 {
168 	iidesc_t *iidesc = arg1;
169 	iidesc_match_t *match = arg2;
170 	if (streq(iidesc->ii_name, match->iim_name) == 0)
171 		return (0);
172 
173 	switch (iidesc->ii_type) {
174 	case II_GFUN:
175 	case II_GVAR:
176 		if (match->iim_bind == STB_GLOBAL) {
177 			match->iim_ret = iidesc;
178 			return (-1);
179 		} else if (match->iim_fuzzy && match->iim_ret == NULL) {
180 			match->iim_ret = iidesc;
181 			/* continue to look for strong match */
182 			return (0);
183 		}
184 		break;
185 	case II_SFUN:
186 	case II_SVAR:
187 		if (match->iim_bind == STB_LOCAL &&
188 		    match->iim_file != NULL &&
189 		    streq(iidesc->ii_owner, match->iim_file)) {
190 			match->iim_ret = iidesc;
191 			return (-1);
192 		}
193 		break;
194 	default:
195 		break;
196 	}
197 	return (0);
198 }
199 
200 static iidesc_t *
201 find_iidesc(tdata_t *td, iidesc_match_t *match)
202 {
203 	match->iim_ret = NULL;
204 	iter_iidescs_by_name(td, match->iim_name,
205 	    matching_iidesc, match);
206 	return (match->iim_ret);
207 }
208 
209 /*
210  * If we have a weak symbol, attempt to find the strong symbol it will
211  * resolve to.  Note: the code where this actually happens is in
212  * sym_process() in cmd/sgs/libld/common/syms.c
213  *
214  * Finding the matching symbol is unfortunately not trivial.  For a
215  * symbol to be a candidate, it must:
216  *
217  * - have the same type (function, object)
218  * - have the same value (address)
219  * - have the same size
220  * - not be another weak symbol
221  * - belong to the same section (checked via section index)
222  *
223  * If such a candidate is global, then we assume we've found it.  The
224  * linker generates the symbol table such that the curfile might be
225  * incorrect; this is OK for global symbols, since find_iidesc() doesn't
226  * need to check for the source file for the symbol.
227  *
228  * We might have found a strong local symbol, where the curfile is
229  * accurate and matches that of the weak symbol.  We assume this is a
230  * reasonable match.
231  *
232  * If we've got a local symbol with a non-matching curfile, there are
233  * two possibilities.  Either this is a completely different symbol, or
234  * it's a once-global symbol that was scoped to local via a mapfile.  In
235  * the latter case, curfile is likely inaccurate since the linker does
236  * not preserve the needed curfile in the order of the symbol table (see
237  * the comments about locally scoped symbols in libld's update_osym()).
238  * As we can't tell this case from the former one, we use this symbol
239  * iff no other matching symbol is found.
240  *
241  * What we really need here is a SUNW section containing weak<->strong
242  * mappings that we can consume.
243  */
244 static int
245 check_for_weak(GElf_Sym *weak, char const *weakfile,
246     Elf_Data *data, int nent, Elf_Data *strdata,
247     GElf_Sym *retsym, char **curfilep)
248 {
249 	char *curfile = NULL;
250 	char *tmpfile1 = NULL;
251 	GElf_Sym tmpsym;
252 	int candidate = 0;
253 	int i;
254 	tmpsym.st_info = 0;
255 	tmpsym.st_name = 0;
256 
257 	if (GELF_ST_BIND(weak->st_info) != STB_WEAK)
258 		return (0);
259 
260 	for (i = 0; i < nent; i++) {
261 		GElf_Sym sym;
262 		uchar_t type;
263 
264 		if (gelf_getsym(data, i, &sym) == NULL)
265 			continue;
266 
267 		type = GELF_ST_TYPE(sym.st_info);
268 
269 		if (type == STT_FILE)
270 			curfile = (char *)strdata->d_buf + sym.st_name;
271 
272 		if (GELF_ST_TYPE(weak->st_info) != type ||
273 		    weak->st_value != sym.st_value)
274 			continue;
275 
276 		if (weak->st_size != sym.st_size)
277 			continue;
278 
279 		if (GELF_ST_BIND(sym.st_info) == STB_WEAK)
280 			continue;
281 
282 		if (sym.st_shndx != weak->st_shndx)
283 			continue;
284 
285 		if (GELF_ST_BIND(sym.st_info) == STB_LOCAL &&
286 		    (curfile == NULL || weakfile == NULL ||
287 		    strcmp(curfile, weakfile) != 0)) {
288 			candidate = 1;
289 			tmpfile1 = curfile;
290 			tmpsym = sym;
291 			continue;
292 		}
293 
294 		*curfilep = curfile;
295 		*retsym = sym;
296 		return (1);
297 	}
298 
299 	if (candidate) {
300 		*curfilep = tmpfile1;
301 		*retsym = tmpsym;
302 		return (1);
303 	}
304 
305 	return (0);
306 }
307 
308 /*
309  * When we've found the underlying symbol's type description
310  * for a weak symbol, we need to copy it and rename it to match
311  * the weak symbol. We also need to add it to the td so it's
312  * handled along with the others later.
313  */
314 static iidesc_t *
315 copy_from_strong(tdata_t *td, GElf_Sym *sym, iidesc_t *strongdesc,
316     const char *weakname, const char *weakfile)
317 {
318 	iidesc_t *new = iidesc_dup_rename(strongdesc, weakname, weakfile);
319 	uchar_t type = GELF_ST_TYPE(sym->st_info);
320 
321 	switch (type) {
322 	case STT_OBJECT:
323 		new->ii_type = II_GVAR;
324 		break;
325 	case STT_FUNC:
326 		new->ii_type = II_GFUN;
327 		break;
328 	}
329 
330 	hash_add(td->td_iihash, new);
331 
332 	return (new);
333 }
334 
335 /*
336  * Process the symbol table of the output file, associating each symbol
337  * with a type description if possible, and sorting them into functions
338  * and data, maintaining symbol table order.
339  */
340 static iiburst_t *
341 sort_iidescs(Elf *elf, const char *file, tdata_t *td, int fuzzymatch,
342     int dynsym)
343 {
344 	iiburst_t *iiburst;
345 	Elf_Scn *scn;
346 	GElf_Shdr shdr;
347 	Elf_Data *data, *strdata;
348 	int i, stidx;
349 	int nent;
350 	iidesc_match_t match;
351 
352 	match.iim_fuzzy = fuzzymatch;
353 	match.iim_file = NULL;
354 
355 	if ((stidx = findelfsecidx(elf, file,
356 	    dynsym ? ".dynsym" : ".symtab")) < 0)
357 		terminate("%s: Can't open symbol table\n", file);
358 	scn = elf_getscn(elf, stidx);
359 	data = elf_getdata(scn, NULL);
360 	gelf_getshdr(scn, &shdr);
361 	nent = shdr.sh_size / shdr.sh_entsize;
362 
363 	scn = elf_getscn(elf, shdr.sh_link);
364 	strdata = elf_getdata(scn, NULL);
365 
366 	iiburst = iiburst_new(td, nent);
367 
368 	for (i = 0; i < nent; i++) {
369 		GElf_Sym sym;
370 		iidesc_t **tolist;
371 		GElf_Sym ssym;
372 		iidesc_match_t smatch;
373 		int *curr;
374 		iidesc_t *iidesc;
375 
376 		if (gelf_getsym(data, i, &sym) == NULL)
377 			elfterminate(file, "Couldn't read symbol %d", i);
378 
379 		match.iim_name = (char *)strdata->d_buf + sym.st_name;
380 		match.iim_bind = GELF_ST_BIND(sym.st_info);
381 
382 		switch (GELF_ST_TYPE(sym.st_info)) {
383 		case STT_FILE:
384 			match.iim_file = match.iim_name;
385 			continue;
386 		case STT_OBJECT:
387 			tolist = iiburst->iib_objts;
388 			curr = &iiburst->iib_nobjts;
389 			break;
390 		case STT_FUNC:
391 			tolist = iiburst->iib_funcs;
392 			curr = &iiburst->iib_nfuncs;
393 			break;
394 		default:
395 			continue;
396 		}
397 
398 		if (ignore_symbol(&sym, match.iim_name))
399 			continue;
400 
401 		iidesc = find_iidesc(td, &match);
402 
403 		if (iidesc != NULL) {
404 			tolist[*curr] = iidesc;
405 			iidesc->ii_flags |= IIDESC_F_USED;
406 			(*curr)++;
407 			continue;
408 		}
409 
410 		if (!check_for_weak(&sym, match.iim_file, data, nent, strdata,
411 		    &ssym, &smatch.iim_file)) {
412 			(*curr)++;
413 			continue;
414 		}
415 
416 		smatch.iim_fuzzy = fuzzymatch;
417 		smatch.iim_name = (char *)strdata->d_buf + ssym.st_name;
418 		smatch.iim_bind = GELF_ST_BIND(ssym.st_info);
419 
420 		debug(3, "Weak symbol %s resolved to %s\n", match.iim_name,
421 		    smatch.iim_name);
422 
423 		iidesc = find_iidesc(td, &smatch);
424 
425 		if (iidesc != NULL) {
426 			tolist[*curr] = copy_from_strong(td, &sym,
427 			    iidesc, match.iim_name, match.iim_file);
428 			tolist[*curr]->ii_flags |= IIDESC_F_USED;
429 		}
430 
431 		(*curr)++;
432 	}
433 
434 	/*
435 	 * Stabs are generated for every function declared in a given C source
436 	 * file.  When converting an object file, we may encounter a stab that
437 	 * has no symbol table entry because the optimizer has decided to omit
438 	 * that item (for example, an unreferenced static function).  We may
439 	 * see iidescs that do not have an associated symtab entry, and so
440 	 * we do not write records for those functions into the CTF data.
441 	 * All others get marked as a root by this function.
442 	 */
443 	iiburst_types(iiburst);
444 
445 	/*
446 	 * By not adding some of the functions and/or objects, we may have
447 	 * caused some types that were referenced solely by those
448 	 * functions/objects to be suppressed.  This could cause a label,
449 	 * generated prior to the evisceration, to be incorrect.  Find the
450 	 * highest type index, and change the label indicies to be no higher
451 	 * than this value.
452 	 */
453 	tdata_label_newmax(td, iiburst->iib_maxtypeid);
454 
455 	return (iiburst);
456 }
457 
458 static void
459 write_file(Elf *src, const char *srcname, Elf *dst, const char *dstname,
460     caddr_t ctfdata, size_t ctfsize, int flags)
461 {
462 	GElf_Ehdr sehdr, dehdr;
463 	Elf_Scn *sscn, *dscn;
464 	Elf_Data *sdata, *ddata;
465 	GElf_Shdr shdr;
466 	GElf_Word symtab_type;
467 	int symtab_idx = -1;
468 	off_t new_offset = 0;
469 	off_t ctfnameoff = 0;
470 	int dynsym = (flags & CTF_USE_DYNSYM);
471 	int keep_stabs = (flags & CTF_KEEP_STABS);
472 	int *secxlate;
473 	int srcidx, dstidx;
474 	int curnmoff = 0;
475 	int changing = 0;
476 	int pad;
477 	int i;
478 
479 	if (gelf_newehdr(dst, gelf_getclass(src)) == 0)
480 		elfterminate(dstname, "Cannot copy ehdr to temp file");
481 	gelf_getehdr(src, &sehdr);
482 	memcpy(&dehdr, &sehdr, sizeof (GElf_Ehdr));
483 	gelf_update_ehdr(dst, &dehdr);
484 
485 	symtab_type = dynsym ? SHT_DYNSYM : SHT_SYMTAB;
486 
487 	/*
488 	 * Neither the existing stab sections nor the SUNW_ctf sections (new or
489 	 * existing) are SHF_ALLOC'd, so they won't be in areas referenced by
490 	 * program headers.  As such, we can just blindly copy the program
491 	 * headers from the existing file to the new file.
492 	 */
493 	if (sehdr.e_phnum != 0) {
494 		(void) elf_flagelf(dst, ELF_C_SET, ELF_F_LAYOUT);
495 		if (gelf_newphdr(dst, sehdr.e_phnum) == 0)
496 			elfterminate(dstname, "Cannot make phdrs in temp file");
497 
498 		for (i = 0; i < sehdr.e_phnum; i++) {
499 			GElf_Phdr phdr;
500 
501 			gelf_getphdr(src, i, &phdr);
502 			gelf_update_phdr(dst, i, &phdr);
503 		}
504 	}
505 
506 	secxlate = xmalloc(sizeof (int) * sehdr.e_shnum);
507 	for (srcidx = dstidx = 0; srcidx < sehdr.e_shnum; srcidx++) {
508 		Elf_Scn *scn = elf_getscn(src, srcidx);
509 		GElf_Shdr shdr1;
510 		char *sname;
511 
512 		gelf_getshdr(scn, &shdr1);
513 		sname = elf_strptr(src, sehdr.e_shstrndx, shdr1.sh_name);
514 		if (sname == NULL) {
515 			elfterminate(srcname, "Can't find string at %u",
516 			    shdr1.sh_name);
517 		}
518 
519 		if (strcmp(sname, CTF_ELF_SCN_NAME) == 0) {
520 			secxlate[srcidx] = -1;
521 		} else if (!keep_stabs &&
522 		    (strncmp(sname, ".stab", 5) == 0 ||
523 		    strncmp(sname, ".debug", 6) == 0 ||
524 		    strncmp(sname, ".rel.debug", 10) == 0 ||
525 		    strncmp(sname, ".rela.debug", 11) == 0)) {
526 			secxlate[srcidx] = -1;
527 		} else if (dynsym && shdr1.sh_type == SHT_SYMTAB) {
528 			/*
529 			 * If we're building CTF against the dynsym,
530 			 * we'll rip out the symtab so debuggers aren't
531 			 * confused.
532 			 */
533 			secxlate[srcidx] = -1;
534 		} else {
535 			secxlate[srcidx] = dstidx++;
536 			curnmoff += strlen(sname) + 1;
537 		}
538 
539 		new_offset = (off_t)dehdr.e_phoff;
540 	}
541 
542 	for (srcidx = 1; srcidx < sehdr.e_shnum; srcidx++) {
543 		char *sname;
544 
545 		sscn = elf_getscn(src, srcidx);
546 		gelf_getshdr(sscn, &shdr);
547 
548 		if (secxlate[srcidx] == -1) {
549 			changing = 1;
550 			continue;
551 		}
552 
553 		dscn = elf_newscn(dst);
554 
555 		/*
556 		 * If this file has program headers, we need to explicitly lay
557 		 * out sections.  If none of the sections prior to this one have
558 		 * been removed, then we can just use the existing location.  If
559 		 * one or more sections have been changed, then we need to
560 		 * adjust this one to avoid holes.
561 		 */
562 		if (changing && sehdr.e_phnum != 0) {
563 			pad = new_offset % shdr.sh_addralign;
564 
565 			if (pad)
566 				new_offset += shdr.sh_addralign - pad;
567 			shdr.sh_offset = new_offset;
568 		}
569 
570 		shdr.sh_link = secxlate[shdr.sh_link];
571 
572 		if (shdr.sh_type == SHT_REL || shdr.sh_type == SHT_RELA)
573 			shdr.sh_info = secxlate[shdr.sh_info];
574 
575 		sname = elf_strptr(src, sehdr.e_shstrndx, shdr.sh_name);
576 		if (sname == NULL) {
577 			elfterminate(srcname, "Can't find string at %u",
578 			    shdr.sh_name);
579 		}
580 
581 #if !defined(sun)
582 		if (gelf_update_shdr(dscn, &shdr) == 0)
583 			elfterminate(dstname, "Cannot update sect %s", sname);
584 #endif
585 
586 		if ((sdata = elf_getdata(sscn, NULL)) == NULL) {
587 			elfterminate(srcname, "Cannot get sect %s data", sname);
588 		}
589 		if ((ddata = elf_newdata(dscn)) == NULL)
590 			elfterminate(dstname, "Can't make sect %s data", sname);
591 #if defined(sun)
592 		bcopy(sdata, ddata, sizeof (Elf_Data));
593 #else
594 		/*
595 		 * FreeBSD's Elf_Data has private fields which the
596 		 * elf_* routines manage. Simply copying the
597 		 * entire structure corrupts the data. So we need
598 		 * to copy the public fields explictly.
599 		 */
600 		ddata->d_align = sdata->d_align;
601 		ddata->d_off = sdata->d_off;
602 		ddata->d_size = sdata->d_size;
603 		ddata->d_type = sdata->d_type;
604 		ddata->d_version = sdata->d_version;
605 #endif
606 
607 		if (srcidx == sehdr.e_shstrndx) {
608 			char seclen = strlen(CTF_ELF_SCN_NAME);
609 
610 			ddata->d_buf = xmalloc(ddata->d_size + shdr.sh_size +
611 			    seclen + 1);
612 			bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
613 			strcpy((caddr_t)ddata->d_buf + shdr.sh_size,
614 			    CTF_ELF_SCN_NAME);
615 			ctfnameoff = (off_t)shdr.sh_size;
616 			shdr.sh_size += seclen + 1;
617 			ddata->d_size += seclen + 1;
618 
619 			if (sehdr.e_phnum != 0)
620 				changing = 1;
621 		}
622 
623 		if (shdr.sh_type == symtab_type && shdr.sh_entsize != 0) {
624 			int nsym = shdr.sh_size / shdr.sh_entsize;
625 
626 			symtab_idx = secxlate[srcidx];
627 
628 			ddata->d_buf = xmalloc(shdr.sh_size);
629 			bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
630 
631 			for (i = 0; i < nsym; i++) {
632 				GElf_Sym sym;
633 				short newscn;
634 
635 				if (gelf_getsym(ddata, i, &sym) == NULL)
636 					printf("Could not get symbol %d\n",i);
637 
638 				if (sym.st_shndx >= SHN_LORESERVE)
639 					continue;
640 
641 				if ((newscn = secxlate[sym.st_shndx]) !=
642 				    sym.st_shndx) {
643 					sym.st_shndx =
644 					    (newscn == -1 ? 1 : newscn);
645 
646 					gelf_update_sym(ddata, i, &sym);
647 				}
648 			}
649 		}
650 
651 #if !defined(sun)
652 		if ((ddata->d_buf == NULL) && (sdata->d_buf != NULL)) {
653 			ddata->d_buf = xmalloc(shdr.sh_size);
654 			bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
655 		}
656 #endif
657 
658 		if (gelf_update_shdr(dscn, &shdr) == 0)
659 			elfterminate(dstname, "Cannot update sect %s", sname);
660 
661 		new_offset = (off_t)shdr.sh_offset;
662 		if (shdr.sh_type != SHT_NOBITS)
663 			new_offset += shdr.sh_size;
664 	}
665 
666 	if (symtab_idx == -1) {
667 		terminate("%s: Cannot find %s section\n", srcname,
668 		    dynsym ? "SHT_DYNSYM" : "SHT_SYMTAB");
669 	}
670 
671 	/* Add the ctf section */
672 	dscn = elf_newscn(dst);
673 	gelf_getshdr(dscn, &shdr);
674 	shdr.sh_name = ctfnameoff;
675 	shdr.sh_type = SHT_PROGBITS;
676 	shdr.sh_size = ctfsize;
677 	shdr.sh_link = symtab_idx;
678 	shdr.sh_addralign = 4;
679 	if (changing && sehdr.e_phnum != 0) {
680 		pad = new_offset % shdr.sh_addralign;
681 
682 		if (pad)
683 			new_offset += shdr.sh_addralign - pad;
684 
685 		shdr.sh_offset = new_offset;
686 		new_offset += shdr.sh_size;
687 	}
688 
689 	ddata = elf_newdata(dscn);
690 	ddata->d_buf = ctfdata;
691 	ddata->d_size = ctfsize;
692 	ddata->d_align = shdr.sh_addralign;
693 	ddata->d_off = 0;
694 
695 	gelf_update_shdr(dscn, &shdr);
696 
697 	/* update the section header location */
698 	if (sehdr.e_phnum != 0) {
699 		size_t align = gelf_fsize(dst, ELF_T_ADDR, 1, EV_CURRENT);
700 		size_t r = new_offset % align;
701 
702 		if (r)
703 			new_offset += align - r;
704 
705 		dehdr.e_shoff = new_offset;
706 	}
707 
708 	/* commit to disk */
709 	dehdr.e_shstrndx = secxlate[sehdr.e_shstrndx];
710 	gelf_update_ehdr(dst, &dehdr);
711 	if (elf_update(dst, ELF_C_WRITE) < 0)
712 		elfterminate(dstname, "Cannot finalize temp file");
713 
714 	free(secxlate);
715 }
716 
717 static caddr_t
718 make_ctf_data(tdata_t *td, Elf *elf, const char *file, size_t *lenp, int flags)
719 {
720 	iiburst_t *iiburst;
721 	caddr_t data;
722 
723 	iiburst = sort_iidescs(elf, file, td, flags & CTF_FUZZY_MATCH,
724 	    flags & CTF_USE_DYNSYM);
725 	data = ctf_gen(iiburst, lenp, flags & CTF_COMPRESS);
726 
727 	iiburst_free(iiburst);
728 
729 	return (data);
730 }
731 
732 void
733 write_ctf(tdata_t *td, const char *curname, const char *newname, int flags)
734 {
735 	struct stat st;
736 	Elf *elf = NULL;
737 	Elf *telf = NULL;
738 	caddr_t data;
739 	size_t len;
740 	int fd = -1;
741 	int tfd = -1;
742 
743 	(void) elf_version(EV_CURRENT);
744 	if ((fd = open(curname, O_RDONLY)) < 0 || fstat(fd, &st) < 0)
745 		terminate("%s: Cannot open for re-reading", curname);
746 	if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL)
747 		elfterminate(curname, "Cannot re-read");
748 
749 	if ((tfd = open(newname, O_RDWR | O_CREAT | O_TRUNC, st.st_mode)) < 0)
750 		terminate("Cannot open temp file %s for writing", newname);
751 	if ((telf = elf_begin(tfd, ELF_C_WRITE, NULL)) == NULL)
752 		elfterminate(curname, "Cannot write");
753 
754 	data = make_ctf_data(td, elf, curname, &len, flags);
755 	write_file(elf, curname, telf, newname, data, len, flags);
756 	free(data);
757 
758 	elf_end(telf);
759 	elf_end(elf);
760 	(void) close(fd);
761 	(void) close(tfd);
762 }
763