Merge commit 'fdfb62c8fbf6e03ca943243b626360bede206f18'
[unleashed.git] / bin / dis / dis_target.c
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1 /*
2 * CDDL HEADER START
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.
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.
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]
19 * CDDL HEADER END
23 * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
25 * Copyright 2011 Jason King. All rights reserved.
28 #include <assert.h>
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <gelf.h>
32 #include <libelf.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <unistd.h>
37 #include <sys/fcntl.h>
38 #include <sys/stat.h>
39 #include <sys/sysmacros.h>
40 #include <sys/types.h>
42 #include "dis_target.h"
43 #include "dis_util.h"
46 * Standard ELF disassembler target.
48 * We only support disassembly of ELF files, though this target interface could
49 * be extended in the future. Each basic type (target, func, section) contains
50 * enough information to uniquely identify the location within the file. The
51 * interfaces use libelf(3LIB) to do the actual processing of the file.
55 * Symbol table entry type. We maintain our own symbol table sorted by address,
56 * with the symbol name already resolved against the ELF symbol table.
58 typedef struct sym_entry {
59 GElf_Sym se_sym; /* value of symbol */
60 char *se_name; /* name of symbol */
61 int se_shndx; /* section where symbol is located */
62 } sym_entry_t;
65 * Create a map of the virtual address ranges of every section. This will
66 * allow us to create dummpy mappings for unassigned addresses. Otherwise
67 * multiple sections with unassigned addresses will appear to overlap and
68 * mess up symbol resolution (which uses the virtual address).
70 typedef struct dis_shnmap {
71 const char *dm_name; /* name of section */
72 uint64_t dm_start; /* virtual address of section */
73 size_t dm_length; /* address length */
74 boolean_t dm_mapped; /* did we assign the mapping */
75 } dis_shnmap_t;
78 * Target data structure. This structure keeps track of the ELF file
79 * information, a few bits of pre-processed section index information, and
80 * sorted versions of the symbol table. We also keep track of the last symbol
81 * looked up, as the majority of lookups remain within the same symbol.
83 struct dis_tgt {
84 Elf *dt_elf; /* libelf handle */
85 Elf *dt_elf_root; /* main libelf handle (for archives) */
86 const char *dt_filename; /* name of file */
87 int dt_fd; /* underlying file descriptor */
88 size_t dt_shstrndx; /* section index of .shstrtab */
89 size_t dt_symidx; /* section index of symbol table */
90 sym_entry_t *dt_symcache; /* last symbol looked up */
91 sym_entry_t *dt_symtab; /* sorted symbol table */
92 int dt_symcount; /* # of symbol table entries */
93 struct dis_tgt *dt_next; /* next target (for archives) */
94 Elf_Arhdr *dt_arhdr; /* archive header (for archives) */
95 dis_shnmap_t *dt_shnmap; /* section address map */
96 size_t dt_shncount; /* # of sections in target */
100 * Function data structure. We resolve the symbol and lookup the associated ELF
101 * data when building this structure. The offset is calculated based on the
102 * section's starting address.
104 struct dis_func {
105 sym_entry_t *df_sym; /* symbol table reference */
106 Elf_Data *df_data; /* associated ELF data */
107 size_t df_offset; /* offset within data */
111 * Section data structure. We store the entire section header so that we can
112 * determine some properties (such as whether or not it contains text) after
113 * building the structure.
115 struct dis_scn {
116 GElf_Shdr ds_shdr;
117 const char *ds_name;
118 Elf_Data *ds_data;
121 /* Lifted from Psymtab.c, omitting STT_TLS */
122 #define DATA_TYPES \
123 ((1 << STT_OBJECT) | (1 << STT_FUNC) | (1 << STT_COMMON))
124 #define IS_DATA_TYPE(tp) (((1 << (tp)) & DATA_TYPES) != 0)
127 * Save the virtual address range for this section and select the
128 * best section to use as the symbol table. We prefer SHT_SYMTAB
129 * over SHT_DYNSYM.
131 /* ARGSUSED */
132 static void
133 tgt_scn_init(dis_tgt_t *tgt, dis_scn_t *scn, void *data)
135 int *index = data;
137 *index += 1;
139 tgt->dt_shnmap[*index].dm_name = scn->ds_name;
140 tgt->dt_shnmap[*index].dm_start = scn->ds_shdr.sh_addr;
141 tgt->dt_shnmap[*index].dm_length = scn->ds_shdr.sh_size;
142 tgt->dt_shnmap[*index].dm_mapped = B_FALSE;
145 * Prefer SHT_SYMTAB over SHT_DYNSYM
147 if (scn->ds_shdr.sh_type == SHT_DYNSYM && tgt->dt_symidx == 0)
148 tgt->dt_symidx = *index;
149 else if (scn->ds_shdr.sh_type == SHT_SYMTAB)
150 tgt->dt_symidx = *index;
153 static int
154 sym_compare(const void *a, const void *b)
156 const sym_entry_t *syma = a;
157 const sym_entry_t *symb = b;
158 const char *aname = syma->se_name;
159 const char *bname = symb->se_name;
161 if (syma->se_sym.st_value < symb->se_sym.st_value)
162 return (-1);
164 if (syma->se_sym.st_value > symb->se_sym.st_value)
165 return (1);
168 * Prefer functions over non-functions
170 if (GELF_ST_TYPE(syma->se_sym.st_info) !=
171 GELF_ST_TYPE(symb->se_sym.st_info)) {
172 if (GELF_ST_TYPE(syma->se_sym.st_info) == STT_FUNC)
173 return (-1);
174 if (GELF_ST_TYPE(symb->se_sym.st_info) == STT_FUNC)
175 return (1);
179 * For symbols with the same address and type, we sort them according to
180 * a hierarchy:
182 * 1. weak symbols (common name)
183 * 2. global symbols (external name)
184 * 3. local symbols
186 if (GELF_ST_BIND(syma->se_sym.st_info) !=
187 GELF_ST_BIND(symb->se_sym.st_info)) {
188 if (GELF_ST_BIND(syma->se_sym.st_info) == STB_WEAK)
189 return (-1);
190 if (GELF_ST_BIND(symb->se_sym.st_info) == STB_WEAK)
191 return (1);
193 if (GELF_ST_BIND(syma->se_sym.st_info) == STB_GLOBAL)
194 return (-1);
195 if (GELF_ST_BIND(symb->se_sym.st_info) == STB_GLOBAL)
196 return (1);
200 * As a last resort, if we have multiple symbols of the same type at the
201 * same address, prefer the version with the fewest leading underscores.
203 if (aname == NULL)
204 return (-1);
205 if (bname == NULL)
206 return (1);
208 while (*aname == '_' && *bname == '_') {
209 aname++;
210 bname++;
213 if (*bname == '_')
214 return (-1);
215 if (*aname == '_')
216 return (1);
219 * Prefer the symbol with the smaller size.
221 if (syma->se_sym.st_size < symb->se_sym.st_size)
222 return (-1);
223 if (syma->se_sym.st_size > symb->se_sym.st_size)
224 return (1);
227 * We really do have two identical symbols for some reason. Just report
228 * them as equal, and to the lucky one go the spoils.
230 return (0);
234 * Construct an optimized symbol table sorted by starting address.
236 static void
237 construct_symtab(dis_tgt_t *tgt)
239 Elf_Scn *scn;
240 GElf_Shdr shdr;
241 Elf_Data *symdata;
242 int i;
243 GElf_Word *symshndx = NULL;
244 int symshndx_size;
245 sym_entry_t *sym;
246 sym_entry_t *p_symtab = NULL;
247 int nsym = 0; /* count of symbols we're not interested in */
250 * Find the symshndx section, if any
252 for (scn = elf_nextscn(tgt->dt_elf, NULL); scn != NULL;
253 scn = elf_nextscn(tgt->dt_elf, scn)) {
254 if (gelf_getshdr(scn, &shdr) == NULL)
255 break;
256 if (shdr.sh_type == SHT_SYMTAB_SHNDX &&
257 shdr.sh_link == tgt->dt_symidx) {
258 Elf_Data *data;
260 if ((data = elf_getdata(scn, NULL)) != NULL) {
261 symshndx = (GElf_Word *)data->d_buf;
262 symshndx_size = data->d_size /
263 sizeof (GElf_Word);
264 break;
269 if ((scn = elf_getscn(tgt->dt_elf, tgt->dt_symidx)) == NULL)
270 die("%s: failed to get section information", tgt->dt_filename);
271 if (gelf_getshdr(scn, &shdr) == NULL)
272 die("%s: failed to get section header", tgt->dt_filename);
273 if (shdr.sh_entsize == 0)
274 die("%s: symbol table has zero size", tgt->dt_filename);
276 if ((symdata = elf_getdata(scn, NULL)) == NULL)
277 die("%s: failed to get symbol table", tgt->dt_filename);
279 tgt->dt_symcount = symdata->d_size / gelf_fsize(tgt->dt_elf, ELF_T_SYM,
280 1, EV_CURRENT);
282 p_symtab = safe_malloc(tgt->dt_symcount * sizeof (sym_entry_t));
284 for (i = 0, sym = p_symtab; i < tgt->dt_symcount; i++) {
285 if (gelf_getsym(symdata, i, &(sym->se_sym)) == NULL) {
286 warn("%s: gelf_getsym returned NULL for %d",
287 tgt->dt_filename, i);
288 nsym++;
289 continue;
293 * We're only interested in data symbols.
295 if (!IS_DATA_TYPE(GELF_ST_TYPE(sym->se_sym.st_info))) {
296 nsym++;
297 continue;
300 if (sym->se_sym.st_shndx == SHN_XINDEX && symshndx != NULL) {
301 if (i > symshndx_size) {
302 warn("%s: bad SHNX_XINDEX %d",
303 tgt->dt_filename, i);
304 sym->se_shndx = -1;
305 } else {
306 sym->se_shndx = symshndx[i];
308 } else {
309 sym->se_shndx = sym->se_sym.st_shndx;
312 /* Deal with symbols with special section indicies */
313 if (sym->se_shndx == SHN_ABS) {
315 * If st_value == 0, references to these
316 * symbols in code are modified in situ
317 * thus we will never attempt to look
318 * them up.
320 if (sym->se_sym.st_value == 0) {
322 * References to these symbols in code
323 * are modified in situ by the runtime
324 * linker and no code on disk will ever
325 * attempt to look them up.
327 nsym++;
328 continue;
329 } else {
331 * If st_value != 0, (such as examining
332 * something in /system/object/.../object)
333 * the values should resolve to a value
334 * within an existing section (such as
335 * .data). This also means it never needs
336 * to have st_value mapped.
338 sym++;
339 continue;
344 * Ignore the symbol if it has some other special
345 * section index
347 if (sym->se_shndx == SHN_UNDEF ||
348 sym->se_shndx >= SHN_LORESERVE) {
349 nsym++;
350 continue;
353 if ((sym->se_name = elf_strptr(tgt->dt_elf, shdr.sh_link,
354 (size_t)sym->se_sym.st_name)) == NULL) {
355 warn("%s: failed to lookup symbol %d name",
356 tgt->dt_filename, i);
357 nsym++;
358 continue;
362 * If we had to map this section, its symbol value
363 * also needs to be mapped.
365 if (tgt->dt_shnmap[sym->se_shndx].dm_mapped)
366 sym->se_sym.st_value +=
367 tgt->dt_shnmap[sym->se_shndx].dm_start;
369 sym++;
372 tgt->dt_symcount -= nsym;
373 tgt->dt_symtab = reallocarray(p_symtab, tgt->dt_symcount,
374 sizeof (sym_entry_t));
376 qsort(tgt->dt_symtab, tgt->dt_symcount, sizeof (sym_entry_t),
377 sym_compare);
381 * Assign virtual address ranges for sections that need it
383 static void
384 create_addrmap(dis_tgt_t *tgt)
386 uint64_t addr;
387 int i;
389 if (tgt->dt_shnmap == NULL)
390 return;
392 /* find the greatest used address */
393 for (addr = 0, i = 1; i < tgt->dt_shncount; i++)
394 if (tgt->dt_shnmap[i].dm_start > addr)
395 addr = tgt->dt_shnmap[i].dm_start +
396 tgt->dt_shnmap[i].dm_length;
398 addr = P2ROUNDUP(addr, 0x1000);
401 * Assign section a starting address beyond the largest mapped section
402 * if no address was given.
404 for (i = 1; i < tgt->dt_shncount; i++) {
405 if (tgt->dt_shnmap[i].dm_start != 0)
406 continue;
408 tgt->dt_shnmap[i].dm_start = addr;
409 tgt->dt_shnmap[i].dm_mapped = B_TRUE;
410 addr = P2ROUNDUP(addr + tgt->dt_shnmap[i].dm_length, 0x1000);
415 * Create a target backed by an ELF file.
417 dis_tgt_t *
418 dis_tgt_create(const char *file)
420 dis_tgt_t *tgt, *current;
421 int idx;
422 Elf *elf;
423 GElf_Ehdr ehdr;
424 Elf_Arhdr *arhdr = NULL;
425 int cmd;
427 if (elf_version(EV_CURRENT) == EV_NONE)
428 die("libelf(3ELF) out of date");
430 tgt = safe_malloc(sizeof (dis_tgt_t));
432 if ((tgt->dt_fd = open(file, O_RDONLY)) < 0) {
433 warn("%s: failed opening file, reason: %s", file,
434 strerror(errno));
435 free(tgt);
436 return (NULL);
439 if ((tgt->dt_elf_root =
440 elf_begin(tgt->dt_fd, ELF_C_READ, NULL)) == NULL) {
441 warn("%s: invalid or corrupt ELF file", file);
442 dis_tgt_destroy(tgt);
443 return (NULL);
446 current = tgt;
447 cmd = ELF_C_READ;
448 while ((elf = elf_begin(tgt->dt_fd, cmd, tgt->dt_elf_root)) != NULL) {
449 size_t shnum = 0;
451 if (elf_kind(tgt->dt_elf_root) == ELF_K_AR &&
452 (arhdr = elf_getarhdr(elf)) == NULL) {
453 warn("%s: malformed archive", file);
454 dis_tgt_destroy(tgt);
455 return (NULL);
459 * Make sure that this Elf file is sane
461 if (gelf_getehdr(elf, &ehdr) == NULL) {
462 if (arhdr != NULL) {
464 * For archives, we drive on in the face of bad
465 * members. The "/" and "//" members are
466 * special, and should be silently ignored.
468 if (strcmp(arhdr->ar_name, "/") != 0 &&
469 strcmp(arhdr->ar_name, "//") != 0)
470 warn("%s[%s]: invalid file type",
471 file, arhdr->ar_name);
472 cmd = elf_next(elf);
473 (void) elf_end(elf);
474 continue;
477 warn("%s: invalid file type", file);
478 dis_tgt_destroy(tgt);
479 return (NULL);
483 * If we're seeing a new Elf object, then we have an
484 * archive. In this case, we create a new target, and chain it
485 * off the master target. We can later iterate over these
486 * targets using dis_tgt_next().
488 if (current->dt_elf != NULL) {
489 dis_tgt_t *next = safe_malloc(sizeof (dis_tgt_t));
490 next->dt_elf_root = tgt->dt_elf_root;
491 next->dt_fd = -1;
492 current->dt_next = next;
493 current = next;
495 current->dt_elf = elf;
496 current->dt_arhdr = arhdr;
498 if (elf_getshdrstrndx(elf, &current->dt_shstrndx) == -1) {
499 warn("%s: failed to get section string table for "
500 "file", file);
501 dis_tgt_destroy(tgt);
502 return (NULL);
505 if (elf_getshdrnum(elf, &shnum) == -1) {
506 warn("%s: failed to get number of sections in file",
507 file);
508 dis_tgt_destroy(tgt);
509 return (NULL);
512 current->dt_shnmap = safe_malloc(sizeof (dis_shnmap_t) *
513 shnum);
514 current->dt_shncount = shnum;
516 idx = 0;
517 dis_tgt_section_iter(current, tgt_scn_init, &idx);
518 current->dt_filename = file;
520 create_addrmap(current);
521 if (current->dt_symidx != 0)
522 construct_symtab(current);
524 cmd = elf_next(elf);
528 * Final sanity check. If we had an archive with no members, then bail
529 * out with a nice message.
531 if (tgt->dt_elf == NULL) {
532 warn("%s: empty archive\n", file);
533 dis_tgt_destroy(tgt);
534 return (NULL);
537 return (tgt);
541 * Return the filename associated with the target.
543 const char *
544 dis_tgt_name(dis_tgt_t *tgt)
546 return (tgt->dt_filename);
550 * Return the archive member name, if any.
552 const char *
553 dis_tgt_member(dis_tgt_t *tgt)
555 if (tgt->dt_arhdr)
556 return (tgt->dt_arhdr->ar_name);
557 else
558 return (NULL);
562 * Return the Elf_Ehdr associated with this target. Needed to determine which
563 * disassembler to use.
565 void
566 dis_tgt_ehdr(dis_tgt_t *tgt, GElf_Ehdr *ehdr)
568 (void) gelf_getehdr(tgt->dt_elf, ehdr);
572 * Return the next target in the list, if this is an archive.
574 dis_tgt_t *
575 dis_tgt_next(dis_tgt_t *tgt)
577 return (tgt->dt_next);
581 * Destroy a target and free up any associated memory.
583 void
584 dis_tgt_destroy(dis_tgt_t *tgt)
586 dis_tgt_t *current, *next;
588 current = tgt->dt_next;
589 while (current != NULL) {
590 next = current->dt_next;
591 if (current->dt_elf)
592 (void) elf_end(current->dt_elf);
593 free(current->dt_symtab);
594 free(current);
595 current = next;
598 if (tgt->dt_elf)
599 (void) elf_end(tgt->dt_elf);
600 if (tgt->dt_elf_root)
601 (void) elf_end(tgt->dt_elf_root);
603 free(tgt->dt_symtab);
605 free(tgt);
609 * Given an address, return the section it is in and set the offset within
610 * the section.
612 const char *
613 dis_find_section(dis_tgt_t *tgt, uint64_t addr, off_t *offset)
615 int i;
617 for (i = 1; i < tgt->dt_shncount; i++) {
618 if ((addr >= tgt->dt_shnmap[i].dm_start) &&
619 (addr < tgt->dt_shnmap[i].dm_start +
620 tgt->dt_shnmap[i].dm_length)) {
621 *offset = addr - tgt->dt_shnmap[i].dm_start;
622 return (tgt->dt_shnmap[i].dm_name);
626 *offset = 0;
627 return (NULL);
631 * Given an address, returns the name of the corresponding symbol, as well as
632 * the offset within that symbol. If no matching symbol is found, then NULL is
633 * returned.
635 * If 'cache_result' is specified, then we keep track of the resulting symbol.
636 * This cached result is consulted first on subsequent lookups in order to avoid
637 * unecessary lookups. This flag should be used for resolving the current PC,
638 * as the majority of addresses stay within the current function.
640 const char *
641 dis_tgt_lookup(dis_tgt_t *tgt, uint64_t addr, off_t *offset, int cache_result,
642 size_t *size, int *isfunc)
644 int lo, hi, mid;
645 sym_entry_t *sym, *osym, *match;
646 int found;
648 *offset = 0;
649 *size = 0;
650 if (isfunc != NULL)
651 *isfunc = 0;
653 if (tgt->dt_symcache != NULL &&
654 addr >= tgt->dt_symcache->se_sym.st_value &&
655 addr < tgt->dt_symcache->se_sym.st_value +
656 tgt->dt_symcache->se_sym.st_size) {
657 sym = tgt->dt_symcache;
658 *offset = addr - sym->se_sym.st_value;
659 *size = sym->se_sym.st_size;
660 if (isfunc != NULL)
661 *isfunc = (GELF_ST_TYPE(sym->se_sym.st_info) ==
662 STT_FUNC);
663 return (sym->se_name);
666 lo = 0;
667 hi = (tgt->dt_symcount - 1);
668 found = 0;
669 match = osym = NULL;
670 while (lo <= hi) {
671 mid = (lo + hi) / 2;
673 sym = &tgt->dt_symtab[mid];
675 if (addr >= sym->se_sym.st_value &&
676 addr < sym->se_sym.st_value + sym->se_sym.st_size &&
677 (!found || sym->se_sym.st_value > osym->se_sym.st_value)) {
678 osym = sym;
679 found = 1;
680 } else if (addr == sym->se_sym.st_value) {
682 * Particularly for .plt objects, it's possible to have
683 * a zero sized object. We want to return this, but we
684 * want it to be a last resort.
686 match = sym;
689 if (addr < sym->se_sym.st_value)
690 hi = mid - 1;
691 else
692 lo = mid + 1;
695 if (!found) {
696 if (match)
697 osym = match;
698 else
699 return (NULL);
703 * Walk backwards to find the best match.
705 do {
706 sym = osym;
708 if (osym == tgt->dt_symtab)
709 break;
711 osym = osym - 1;
712 } while ((sym->se_sym.st_value == osym->se_sym.st_value) &&
713 (addr >= osym->se_sym.st_value) &&
714 (addr < osym->se_sym.st_value + osym->se_sym.st_size));
716 if (cache_result)
717 tgt->dt_symcache = sym;
719 *offset = addr - sym->se_sym.st_value;
720 *size = sym->se_sym.st_size;
721 if (isfunc)
722 *isfunc = (GELF_ST_TYPE(sym->se_sym.st_info) == STT_FUNC);
724 return (sym->se_name);
728 * Given an address, return the starting offset of the next symbol in the file.
729 * Only needed on variable length instruction architectures.
731 off_t
732 dis_tgt_next_symbol(dis_tgt_t *tgt, uint64_t addr)
734 sym_entry_t *sym;
736 sym = (tgt->dt_symcache != NULL) ? tgt->dt_symcache : tgt->dt_symtab;
738 while (sym != (tgt->dt_symtab + tgt->dt_symcount)) {
739 if (sym->se_sym.st_value >= addr)
740 return (sym->se_sym.st_value - addr);
741 sym++;
744 return (0);
748 * Iterate over all sections in the target, executing the given callback for
749 * each.
751 void
752 dis_tgt_section_iter(dis_tgt_t *tgt, section_iter_f func, void *data)
754 dis_scn_t sdata;
755 Elf_Scn *scn;
756 int idx;
758 for (scn = elf_nextscn(tgt->dt_elf, NULL), idx = 1; scn != NULL;
759 scn = elf_nextscn(tgt->dt_elf, scn), idx++) {
761 if (gelf_getshdr(scn, &sdata.ds_shdr) == NULL) {
762 warn("%s: failed to get section %d header",
763 tgt->dt_filename, idx);
764 continue;
767 if ((sdata.ds_name = elf_strptr(tgt->dt_elf, tgt->dt_shstrndx,
768 sdata.ds_shdr.sh_name)) == NULL) {
769 warn("%s: failed to get section %d name",
770 tgt->dt_filename, idx);
771 continue;
774 if ((sdata.ds_data = elf_getdata(scn, NULL)) == NULL) {
775 warn("%s: failed to get data for section '%s'",
776 tgt->dt_filename, sdata.ds_name);
777 continue;
781 * dis_tgt_section_iter is also used before the section map
782 * is initialized, so only check when we need to. If the
783 * section map is uninitialized, it will return 0 and have
784 * no net effect.
786 if (sdata.ds_shdr.sh_addr == 0)
787 sdata.ds_shdr.sh_addr = tgt->dt_shnmap[idx].dm_start;
789 func(tgt, &sdata, data);
794 * Return 1 if the given section contains text, 0 otherwise.
797 dis_section_istext(dis_scn_t *scn)
799 return ((scn->ds_shdr.sh_type == SHT_PROGBITS) &&
800 (scn->ds_shdr.sh_flags == (SHF_ALLOC | SHF_EXECINSTR)));
804 * Return a pointer to the section data.
806 void *
807 dis_section_data(dis_scn_t *scn)
809 return (scn->ds_data->d_buf);
813 * Return the size of the section data.
815 size_t
816 dis_section_size(dis_scn_t *scn)
818 return (scn->ds_data->d_size);
822 * Return the address for the given section.
824 uint64_t
825 dis_section_addr(dis_scn_t *scn)
827 return (scn->ds_shdr.sh_addr);
831 * Return the name of the current section.
833 const char *
834 dis_section_name(dis_scn_t *scn)
836 return (scn->ds_name);
840 * Create an allocated copy of the given section
842 dis_scn_t *
843 dis_section_copy(dis_scn_t *scn)
845 dis_scn_t *new;
847 new = safe_malloc(sizeof (dis_scn_t));
848 (void) memcpy(new, scn, sizeof (dis_scn_t));
850 return (new);
854 * Free section memory
856 void
857 dis_section_free(dis_scn_t *scn)
859 free(scn);
863 * Iterate over all functions in the target, executing the given callback for
864 * each one.
866 void
867 dis_tgt_function_iter(dis_tgt_t *tgt, function_iter_f func, void *data)
869 int i;
870 sym_entry_t *sym;
871 dis_func_t df;
872 Elf_Scn *scn;
873 GElf_Shdr shdr;
875 for (i = 0, sym = tgt->dt_symtab; i < tgt->dt_symcount; i++, sym++) {
877 /* ignore non-functions */
878 if ((GELF_ST_TYPE(sym->se_sym.st_info) != STT_FUNC) ||
879 (sym->se_name == NULL) ||
880 (sym->se_sym.st_size == 0) ||
881 (sym->se_shndx >= SHN_LORESERVE))
882 continue;
884 /* get the ELF data associated with this function */
885 if ((scn = elf_getscn(tgt->dt_elf, sym->se_shndx)) == NULL ||
886 gelf_getshdr(scn, &shdr) == NULL ||
887 (df.df_data = elf_getdata(scn, NULL)) == NULL ||
888 df.df_data->d_size == 0) {
889 warn("%s: failed to read section %d",
890 tgt->dt_filename, sym->se_shndx);
891 continue;
894 if (tgt->dt_shnmap[sym->se_shndx].dm_mapped)
895 shdr.sh_addr = tgt->dt_shnmap[sym->se_shndx].dm_start;
898 * Verify that the address lies within the section that we think
899 * it does.
901 if (sym->se_sym.st_value < shdr.sh_addr ||
902 (sym->se_sym.st_value + sym->se_sym.st_size) >
903 (shdr.sh_addr + shdr.sh_size)) {
904 warn("%s: bad section %d for address %p",
905 tgt->dt_filename, sym->se_sym.st_shndx,
906 sym->se_sym.st_value);
907 continue;
910 df.df_sym = sym;
911 df.df_offset = sym->se_sym.st_value - shdr.sh_addr;
913 func(tgt, &df, data);
918 * Return the data associated with a given function.
920 void *
921 dis_function_data(dis_func_t *func)
923 return ((char *)func->df_data->d_buf + func->df_offset);
927 * Return the size of a function.
929 size_t
930 dis_function_size(dis_func_t *func)
932 return (func->df_sym->se_sym.st_size);
936 * Return the address of a function.
938 uint64_t
939 dis_function_addr(dis_func_t *func)
941 return (func->df_sym->se_sym.st_value);
945 * Return the name of the function
947 const char *
948 dis_function_name(dis_func_t *func)
950 return (func->df_sym->se_name);
954 * Return a copy of a function.
956 dis_func_t *
957 dis_function_copy(dis_func_t *func)
959 dis_func_t *new;
961 new = safe_malloc(sizeof (dis_func_t));
962 (void) memcpy(new, func, sizeof (dis_func_t));
964 return (new);
968 * Free function memory
970 void
971 dis_function_free(dis_func_t *func)
973 free(func);