1 /* $NetBSD: symtab.c,v 1.2 2013/08/29 15:01:57 christos Exp $ */
4 * Copyright (c) 2012 The NetBSD Foundation, Inc.
7 * This code is derived from software contributed to The NetBSD Foundation
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
31 #include <sys/cdefs.h>
42 #define ELF_ST_BIND(x) ((x) >> 4)
45 #define ELF_ST_TYPE(x) (((unsigned int)x) & 0xf)
59 struct symbol *symbols;
63 address_compare(const void *a, const void *b)
65 const struct symbol *sa = a;
66 const struct symbol *sb = b;
67 return (int)(intmax_t)(sa->st_value - sb->st_value);
71 symtab_destroy(symtab_t *s)
75 for (size_t i = 0; i < s->nsymbols; i++)
76 free(s->symbols[i].st_name);
82 symtab_create(int fd, int bind, int type)
88 if (elf_version(EV_CURRENT) == EV_NONE) {
89 warnx("Elf Library is out of date.");
93 elf = elf_begin(fd, ELF_C_READ, NULL);
95 warnx("Error opening elf file: %s", elf_errmsg(elf_errno()));
98 st = calloc(1, sizeof(*st));
100 warnx("Error allocating symbol table");
105 while ((scn = elf_nextscn(elf, scn)) != NULL) {
111 gelf_getshdr(scn, &shdr);
112 if(shdr.sh_type != SHT_SYMTAB)
115 edata = elf_getdata(scn, NULL);
116 ns = shdr.sh_size / shdr.sh_entsize;
117 s = calloc(ns, sizeof(*s));
119 warn("Cannot allocate %zu symbols", ns);
124 for (size_t i = 0; i < ns; i++) {
126 gelf_getsym(edata, (int)i, &sym);
129 (unsigned)bind != ELF_ST_BIND(sym.st_info))
133 (unsigned)type != ELF_ST_TYPE(sym.st_info))
136 s->st_value = sym.st_value;
137 s->st_info = sym.st_info;
139 elf_strptr(elf, shdr.sh_link, sym.st_name));
140 if (s->st_name == NULL)
144 st->nsymbols = s - st->symbols;
145 if (st->nsymbols == 0) {
146 warnx("No symbols found");
149 qsort(st->symbols, st->nsymbols, sizeof(*st->symbols),
162 symtab_find(const symtab_t *st, const void *p, Dl_info *dli)
164 struct symbol *s = st->symbols;
165 size_t ns = st->nsymbols;
169 uintptr_t dd, sd, me = (uintptr_t)p;
172 if (s[mid].st_value < me)
174 else if (s[mid].st_value > me)
184 dd = me - (uintptr_t)dli->dli_saddr;
185 sd = me - s[mid].st_value;
187 dli->dli_saddr = (void *)s[mid].st_value;
188 dli->dli_sname = s[mid].st_name;