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      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 /*
     27  * Routines for preparing tdata trees for conversion into CTF data, and
     28  * for placing the resulting data into an output file.
     29  */
     30 
     31 #if HAVE_NBTOOL_CONFIG_H
     32 # include "nbtool_config.h"
     33 #endif
     34 
     35 #include <stdio.h>
     36 #include <stdlib.h>
     37 #include <strings.h>
     38 #include <sys/types.h>
     39 #include <sys/stat.h>
     40 #include <fcntl.h>
     41 #include <libelf.h>
     42 #include <gelf.h>
     43 #include <unistd.h>
     44 
     45 #include "ctftools.h"
     46 #include "list.h"
     47 #include "memory.h"
     48 #include "traverse.h"
     49 #include "symbol.h"
     50 
     51 typedef struct iidesc_match {
     52 	int iim_fuzzy;
     53 	iidesc_t *iim_ret;
     54 	char *iim_name;
     55 	char *iim_file;
     56 	uchar_t iim_bind;
     57 } iidesc_match_t;
     58 
     59 static int
     60 burst_iitypes(void *data, void *arg)
     61 {
     62 	iidesc_t *ii = data;
     63 	iiburst_t *iiburst = arg;
     64 
     65 	switch (ii->ii_type) {
     66 	case II_GFUN:
     67 	case II_SFUN:
     68 	case II_GVAR:
     69 	case II_SVAR:
     70 		if (!(ii->ii_flags & IIDESC_F_USED))
     71 			return (0);
     72 		break;
     73 	default:
     74 		break;
     75 	}
     76 
     77 	ii->ii_dtype->t_flags |= TDESC_F_ISROOT;
     78 	(void) iitraverse_td(ii, iiburst->iib_tdtd);
     79 	return (1);
     80 }
     81 
     82 /*ARGSUSED1*/
     83 static int
     84 save_type_by_id(tdesc_t *tdp, tdesc_t **tdpp __unused, void *private)
     85 {
     86 	iiburst_t *iiburst = private;
     87 
     88 	/*
     89 	 * Doing this on every node is horribly inefficient, but given that
     90 	 * we may be suppressing some types, we can't trust nextid in the
     91 	 * tdata_t.
     92 	 */
     93 	if (tdp->t_id > iiburst->iib_maxtypeid)
     94 		iiburst->iib_maxtypeid = tdp->t_id;
     95 
     96 	slist_add(&iiburst->iib_types, tdp, tdesc_idcmp);
     97 
     98 	return (1);
     99 }
    100 
    101 static tdtrav_cb_f burst_types_cbs[] = {
    102 	NULL,
    103 	save_type_by_id,	/* intrinsic */
    104 	save_type_by_id,	/* pointer */
    105 	save_type_by_id,	/* reference */
    106 	save_type_by_id,	/* array */
    107 	save_type_by_id,	/* function */
    108 	save_type_by_id,	/* struct */
    109 	save_type_by_id,	/* union */
    110 	save_type_by_id,	/* class */
    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 		nent = 0;
    358 	} else {
    359 		scn = elf_getscn(elf, stidx);
    360 		data = elf_getdata(scn, NULL);
    361 		gelf_getshdr(scn, &shdr);
    362 		nent = shdr.sh_size / shdr.sh_entsize;
    363 
    364 		scn = elf_getscn(elf, shdr.sh_link);
    365 		strdata = elf_getdata(scn, NULL);
    366 	}
    367 
    368 	iiburst = iiburst_new(td, nent);
    369 
    370 	for (i = 0; i < nent; i++) {
    371 		GElf_Sym sym;
    372 		char *bname;
    373 		iidesc_t **tolist;
    374 		GElf_Sym ssym;
    375 		iidesc_match_t smatch;
    376 		int *curr;
    377 		iidesc_t *iidesc;
    378 
    379 		if (gelf_getsym(data, i, &sym) == NULL)
    380 			elfterminate(file, "Couldn't read symbol %d", i);
    381 
    382 		match.iim_name = (char *)strdata->d_buf + sym.st_name;
    383 		match.iim_bind = GELF_ST_BIND(sym.st_info);
    384 
    385 		switch (GELF_ST_TYPE(sym.st_info)) {
    386 		case STT_FILE:
    387 			bname = strrchr(match.iim_name, '/');
    388 			match.iim_file = bname == NULL ? match.iim_name : bname + 1;
    389 			continue;
    390 		case STT_OBJECT:
    391 			tolist = iiburst->iib_objts;
    392 			curr = &iiburst->iib_nobjts;
    393 			break;
    394 		case STT_FUNC:
    395 			tolist = iiburst->iib_funcs;
    396 			curr = &iiburst->iib_nfuncs;
    397 			break;
    398 		default:
    399 			continue;
    400 		}
    401 
    402 		if (ignore_symbol(&sym, match.iim_name))
    403 			continue;
    404 
    405 		iidesc = find_iidesc(td, &match);
    406 
    407 		if (iidesc != NULL) {
    408 			tolist[*curr] = iidesc;
    409 			iidesc->ii_flags |= IIDESC_F_USED;
    410 			(*curr)++;
    411 			continue;
    412 		}
    413 
    414 		if (!check_for_weak(&sym, match.iim_file, data, nent, strdata,
    415 		    &ssym, &smatch.iim_file)) {
    416 			(*curr)++;
    417 			continue;
    418 		}
    419 
    420 		smatch.iim_fuzzy = fuzzymatch;
    421 		smatch.iim_name = (char *)strdata->d_buf + ssym.st_name;
    422 		smatch.iim_bind = GELF_ST_BIND(ssym.st_info);
    423 
    424 		debug(3, "Weak symbol %s resolved to %s\n", match.iim_name,
    425 		    smatch.iim_name);
    426 
    427 		iidesc = find_iidesc(td, &smatch);
    428 
    429 		if (iidesc != NULL) {
    430 			tolist[*curr] = copy_from_strong(td, &sym,
    431 			    iidesc, match.iim_name, match.iim_file);
    432 			tolist[*curr]->ii_flags |= IIDESC_F_USED;
    433 		}
    434 
    435 		(*curr)++;
    436 	}
    437 
    438 	/*
    439 	 * Stabs are generated for every function declared in a given C source
    440 	 * file.  When converting an object file, we may encounter a stab that
    441 	 * has no symbol table entry because the optimizer has decided to omit
    442 	 * that item (for example, an unreferenced static function).  We may
    443 	 * see iidescs that do not have an associated symtab entry, and so
    444 	 * we do not write records for those functions into the CTF data.
    445 	 * All others get marked as a root by this function.
    446 	 */
    447 	iiburst_types(iiburst);
    448 
    449 	/*
    450 	 * By not adding some of the functions and/or objects, we may have
    451 	 * caused some types that were referenced solely by those
    452 	 * functions/objects to be suppressed.  This could cause a label,
    453 	 * generated prior to the evisceration, to be incorrect.  Find the
    454 	 * highest type index, and change the label indicies to be no higher
    455 	 * than this value.
    456 	 */
    457 	tdata_label_newmax(td, iiburst->iib_maxtypeid);
    458 
    459 	return (iiburst);
    460 }
    461 
    462 static void
    463 write_file(Elf *src, const char *srcname, Elf *dst, const char *dstname,
    464     caddr_t ctfdata, size_t ctfsize, int flags)
    465 {
    466 	GElf_Ehdr sehdr, dehdr;
    467 	Elf_Scn *sscn, *dscn;
    468 	Elf_Data *sdata, *ddata;
    469 	GElf_Shdr shdr;
    470 	GElf_Word symtab_type;
    471 	int symtab_idx = -1;
    472 	off_t new_offset = 0;
    473 	off_t ctfnameoff = 0;
    474 	int dynsym = (flags & CTF_USE_DYNSYM);
    475 	int keep_stabs = (flags & CTF_KEEP_STABS);
    476 	int *secxlate;
    477 	int srcidx, dstidx;
    478 	int curnmoff = 0;
    479 	int changing = 0;
    480 	int pad;
    481 	int i;
    482 
    483 	if (gelf_newehdr(dst, gelf_getclass(src)) == NULL)
    484 		elfterminate(dstname, "Cannot copy ehdr to temp file");
    485 	gelf_getehdr(src, &sehdr);
    486 	memcpy(&dehdr, &sehdr, sizeof (GElf_Ehdr));
    487 	gelf_update_ehdr(dst, &dehdr);
    488 
    489 	symtab_type = dynsym ? SHT_DYNSYM : SHT_SYMTAB;
    490 
    491 	/*
    492 	 * Neither the existing stab sections nor the SUNW_ctf sections (new or
    493 	 * existing) are SHF_ALLOC'd, so they won't be in areas referenced by
    494 	 * program headers.  As such, we can just blindly copy the program
    495 	 * headers from the existing file to the new file.
    496 	 */
    497 	if (sehdr.e_phnum != 0) {
    498 		(void) elf_flagelf(dst, ELF_C_SET, ELF_F_LAYOUT);
    499 		if (gelf_newphdr(dst, sehdr.e_phnum) == NULL)
    500 			elfterminate(dstname, "Cannot make phdrs in temp file");
    501 
    502 		for (i = 0; i < sehdr.e_phnum; i++) {
    503 			GElf_Phdr phdr;
    504 
    505 			gelf_getphdr(src, i, &phdr);
    506 			gelf_update_phdr(dst, i, &phdr);
    507 		}
    508 	}
    509 
    510 	secxlate = xmalloc(sizeof (int) * sehdr.e_shnum);
    511 	for (srcidx = dstidx = 0; srcidx < sehdr.e_shnum; srcidx++) {
    512 		Elf_Scn *scn = elf_getscn(src, srcidx);
    513 		GElf_Shdr shdr1;
    514 		char *sname;
    515 
    516 		gelf_getshdr(scn, &shdr1);
    517 		sname = elf_strptr(src, sehdr.e_shstrndx, shdr1.sh_name);
    518 		if (sname == NULL) {
    519 			elfterminate(srcname, "Can't find string at %u",
    520 			    shdr1.sh_name);
    521 		}
    522 
    523 		if (strcmp(sname, CTF_ELF_SCN_NAME) == 0) {
    524 			secxlate[srcidx] = -1;
    525 		} else if (!keep_stabs &&
    526 		    (strncmp(sname, ".stab", 5) == 0 ||
    527 		    strncmp(sname, ".debug", 6) == 0 ||
    528 		    strncmp(sname, ".rel.debug", 10) == 0 ||
    529 		    strncmp(sname, ".rela.debug", 11) == 0)) {
    530 			secxlate[srcidx] = -1;
    531 		} else if (dynsym && shdr1.sh_type == SHT_SYMTAB) {
    532 			/*
    533 			 * If we're building CTF against the dynsym,
    534 			 * we'll rip out the symtab so debuggers aren't
    535 			 * confused.
    536 			 */
    537 			secxlate[srcidx] = -1;
    538 		} else {
    539 			secxlate[srcidx] = dstidx++;
    540 			curnmoff += strlen(sname) + 1;
    541 		}
    542 
    543 		new_offset = (off_t)dehdr.e_phoff;
    544 	}
    545 
    546 	for (srcidx = 1; srcidx < sehdr.e_shnum; srcidx++) {
    547 		char *sname;
    548 
    549 		sscn = elf_getscn(src, srcidx);
    550 		gelf_getshdr(sscn, &shdr);
    551 
    552 		if (secxlate[srcidx] == -1) {
    553 			changing = 1;
    554 			continue;
    555 		}
    556 
    557 		dscn = elf_newscn(dst);
    558 
    559 		/*
    560 		 * If this file has program headers, we need to explicitly lay
    561 		 * out sections.  If none of the sections prior to this one have
    562 		 * been removed, then we can just use the existing location.  If
    563 		 * one or more sections have been changed, then we need to
    564 		 * adjust this one to avoid holes.
    565 		 */
    566 		if (changing && sehdr.e_phnum != 0) {
    567 			pad = new_offset % shdr.sh_addralign;
    568 
    569 			if (pad)
    570 				new_offset += shdr.sh_addralign - pad;
    571 			shdr.sh_offset = new_offset;
    572 		}
    573 
    574 		shdr.sh_link = secxlate[shdr.sh_link];
    575 
    576 		if (shdr.sh_type == SHT_REL || shdr.sh_type == SHT_RELA)
    577 			shdr.sh_info = secxlate[shdr.sh_info];
    578 
    579 		sname = elf_strptr(src, sehdr.e_shstrndx, shdr.sh_name);
    580 		if (sname == NULL) {
    581 			elfterminate(srcname, "Can't find string at %u",
    582 			    shdr.sh_name);
    583 		}
    584 
    585 #ifndef illumos
    586 		if (gelf_update_shdr(dscn, &shdr) == 0)
    587 			elfterminate(dstname, "Cannot update sect %s", sname);
    588 #endif
    589 
    590 		if ((sdata = elf_getdata(sscn, NULL)) == NULL)
    591 			elfterminate(srcname, "Cannot get sect %s data", sname);
    592 		if ((ddata = elf_newdata(dscn)) == NULL)
    593 			elfterminate(dstname, "Can't make sect %s data", sname);
    594 #ifdef illumos
    595 		bcopy(sdata, ddata, sizeof (Elf_Data));
    596 #else
    597 		/*
    598 		 * FreeBSD's Elf_Data has private fields which the
    599 		 * elf_* routines manage. Simply copying the
    600 		 * entire structure corrupts the data. So we need
    601 		 * to copy the public fields explictly.
    602 		 */
    603 		ddata->d_align = sdata->d_align;
    604 		ddata->d_off = sdata->d_off;
    605 		ddata->d_size = sdata->d_size;
    606 		ddata->d_type = sdata->d_type;
    607 		ddata->d_version = sdata->d_version;
    608 #endif
    609 
    610 		if (srcidx == sehdr.e_shstrndx) {
    611 			char seclen = strlen(CTF_ELF_SCN_NAME);
    612 
    613 			ddata->d_buf = xmalloc(ddata->d_size + shdr.sh_size +
    614 			    seclen + 1);
    615 			bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
    616 			strcpy((caddr_t)ddata->d_buf + shdr.sh_size,
    617 			    CTF_ELF_SCN_NAME);
    618 			ctfnameoff = (off_t)shdr.sh_size;
    619 			shdr.sh_size += seclen + 1;
    620 			ddata->d_size += seclen + 1;
    621 
    622 			if (sehdr.e_phnum != 0)
    623 				changing = 1;
    624 		}
    625 
    626 		if (shdr.sh_type == symtab_type && shdr.sh_entsize != 0) {
    627 			int nsym = shdr.sh_size / shdr.sh_entsize;
    628 
    629 			symtab_idx = secxlate[srcidx];
    630 
    631 			ddata->d_buf = xmalloc(shdr.sh_size);
    632 			bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
    633 
    634 			for (i = 0; i < nsym; i++) {
    635 				GElf_Sym sym;
    636 				short newscn;
    637 
    638 				if (gelf_getsym(ddata, i, &sym) == NULL)
    639 					printf("Could not get symbol %d\n",i);
    640 
    641 				if (sym.st_shndx >= SHN_LORESERVE)
    642 					continue;
    643 
    644 				if ((newscn = secxlate[sym.st_shndx]) !=
    645 				    sym.st_shndx) {
    646 					sym.st_shndx =
    647 					    (newscn == -1 ? 1 : newscn);
    648 
    649 					gelf_update_sym(ddata, i, &sym);
    650 				}
    651 			}
    652 		}
    653 
    654 #ifndef illumos
    655 		if (ddata->d_buf == NULL && sdata->d_buf != NULL) {
    656 			ddata->d_buf = xmalloc(shdr.sh_size);
    657 			bcopy(sdata->d_buf, ddata->d_buf, shdr.sh_size);
    658 		}
    659 #endif
    660 
    661 		if (gelf_update_shdr(dscn, &shdr) == 0)
    662 			elfterminate(dstname, "Cannot update sect %s", sname);
    663 
    664 		new_offset = (off_t)shdr.sh_offset;
    665 		if (shdr.sh_type != SHT_NOBITS)
    666 			new_offset += shdr.sh_size;
    667 	}
    668 
    669 	if (symtab_idx == -1) {
    670 		goto out;
    671 	}
    672 
    673 	/* Add the ctf section */
    674 	dscn = elf_newscn(dst);
    675 	gelf_getshdr(dscn, &shdr);
    676 	shdr.sh_name = ctfnameoff;
    677 	shdr.sh_type = SHT_PROGBITS;
    678 	shdr.sh_size = ctfsize;
    679 	shdr.sh_link = symtab_idx;
    680 	shdr.sh_addralign = 4;
    681 	if (changing && sehdr.e_phnum != 0) {
    682 		pad = new_offset % shdr.sh_addralign;
    683 
    684 		if (pad)
    685 			new_offset += shdr.sh_addralign - pad;
    686 
    687 		shdr.sh_offset = new_offset;
    688 		new_offset += shdr.sh_size;
    689 	}
    690 
    691 	ddata = elf_newdata(dscn);
    692 	ddata->d_buf = ctfdata;
    693 	ddata->d_size = ctfsize;
    694 	ddata->d_align = shdr.sh_addralign;
    695 	ddata->d_off = 0;
    696 
    697 	gelf_update_shdr(dscn, &shdr);
    698 
    699 	/* update the section header location */
    700 	if (sehdr.e_phnum != 0) {
    701 		size_t align = gelf_fsize(dst, ELF_T_ADDR, 1, EV_CURRENT);
    702 		size_t r = new_offset % align;
    703 
    704 		if (r)
    705 			new_offset += align - r;
    706 
    707 		dehdr.e_shoff = new_offset;
    708 	}
    709 
    710 	/* commit to disk */
    711 	dehdr.e_shstrndx = secxlate[sehdr.e_shstrndx];
    712 	gelf_update_ehdr(dst, &dehdr);
    713 out:
    714 	if (elf_update(dst, ELF_C_WRITE) < 0)
    715 		elfterminate(dstname, "Cannot finalize temp file");
    716 
    717 	free(secxlate);
    718 }
    719 
    720 static caddr_t
    721 make_ctf_data(tdata_t *td, Elf *elf, const char *file, size_t *lenp, int flags)
    722 {
    723 	iiburst_t *iiburst;
    724 	caddr_t data;
    725 
    726 	iiburst = sort_iidescs(elf, file, td, flags & CTF_FUZZY_MATCH,
    727 	    flags & CTF_USE_DYNSYM);
    728 	data = ctf_gen(iiburst, lenp, flags & (CTF_COMPRESS |  CTF_SWAP_BYTES));
    729 
    730 	iiburst_free(iiburst);
    731 
    732 	return (data);
    733 }
    734 
    735 void
    736 write_ctf(tdata_t *td, const char *curname, const char *newname, int flags)
    737 {
    738 	struct stat st;
    739 	Elf *elf = NULL;
    740 	Elf *telf = NULL;
    741 	GElf_Ehdr ehdr;
    742 	caddr_t data;
    743 	size_t len;
    744 	int fd = -1;
    745 	int tfd = -1;
    746 	int byteorder;
    747 
    748 	(void) elf_version(EV_CURRENT);
    749 	if ((fd = open(curname, O_RDONLY)) < 0 || fstat(fd, &st) < 0)
    750 		terminate("%s: Cannot open for re-reading", curname);
    751 	if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL)
    752 		elfterminate(curname, "Cannot re-read");
    753 
    754 	if ((tfd = open(newname, O_RDWR | O_CREAT | O_TRUNC, st.st_mode)) < 0)
    755 		terminate("Cannot open temp file %s for writing", newname);
    756 	if ((telf = elf_begin(tfd, ELF_C_WRITE, NULL)) == NULL)
    757 		elfterminate(curname, "Cannot write");
    758 
    759 	if (gelf_getehdr(elf, &ehdr)) {
    760 #if BYTE_ORDER == BIG_ENDIAN
    761 		byteorder = ELFDATA2MSB;
    762 #else
    763 		byteorder = ELFDATA2LSB;
    764 #endif
    765 		/*
    766 		 * If target and host has the same byte order
    767 		 * clear byte swapping request
    768 		 */
    769 		if  (ehdr.e_ident[EI_DATA] == byteorder)
    770 			flags &= ~CTF_SWAP_BYTES;
    771 	}
    772 	else
    773 		elfterminate(curname, "Failed to get EHDR");
    774 
    775 	data = make_ctf_data(td, elf, curname, &len, flags);
    776 	write_file(elf, curname, telf, newname, data, len, flags);
    777 	free(data);
    778 
    779 	elf_end(telf);
    780 	elf_end(elf);
    781 	(void) close(fd);
    782 	(void) close(tfd);
    783 }
    784