1/*-
2 * Copyright (c) 1983, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#if 0
35/* From: */
36#ifndef lint
37static char sccsid[] = "@(#)gprof.c 8.1 (Berkeley) 6/6/93";
38#endif /* not lint */
39#endif
40
41#include <sys/cdefs.h>
42__FBSDID("$FreeBSD: head/usr.bin/gprof/elf.c 91017 2002-02-21 12:03:06Z bde $");
43
44#include <sys/types.h>
45#include <sys/mman.h>
46#include <sys/stat.h>
47#include <machine/elf.h>
48
49#include <err.h>
50#include <fcntl.h>
51#include <string.h>
52#include <unistd.h>
53
54#include "gprof.h"
55
56static bool wantsym(const Elf_Sym *, const char *);
57
58/* Things which get -E excluded by default. */
59static char *excludes[] = { ".mcount", "_mcleanup", NULL };
60
61int
62elf_getnfile(const char *filename, char ***defaultEs)
63{
64 int fd;
65 Elf_Ehdr h;
66 struct stat s;
67 void *mapbase;
68 const char *base;
69 const Elf_Shdr *shdrs;
70 const Elf_Shdr *sh_symtab;
71 const Elf_Shdr *sh_strtab;
72 const char *strtab;
73 const Elf_Sym *symtab;
74 int symtabct;
75 int i;
76
77 if ((fd = open(filename, O_RDONLY)) == -1)
78 err(1, "%s", filename);
79 if (read(fd, &h, sizeof h) != sizeof h || !IS_ELF(h)) {
80 close(fd);
81 return -1;
82 }
83 if (fstat(fd, &s) == -1)
84 err(1, "Cannot fstat %s", filename);
85 if ((mapbase = mmap(0, s.st_size, PROT_READ, MAP_SHARED, fd, 0)) ==
86 MAP_FAILED)
87 err(1, "Cannot mmap %s", filename);
88 close(fd);
89
90 base = (const char *)mapbase;
91 shdrs = (const Elf_Shdr *)(base + h.e_shoff);
92
93 /* Find the symbol table and associated string table section. */
94 for (i = 1; i < h.e_shnum; i++)
95 if (shdrs[i].sh_type == SHT_SYMTAB)
96 break;
97 if (i == h.e_shnum)
98 errx(1, "%s has no symbol table", filename);
99 sh_symtab = &shdrs[i];
100 sh_strtab = &shdrs[sh_symtab->sh_link];
101
102 symtab = (const Elf_Sym *)(base + sh_symtab->sh_offset);
103 symtabct = sh_symtab->sh_size / sh_symtab->sh_entsize;
104 strtab = (const char *)(base + sh_strtab->sh_offset);
105
106 /* Count the symbols that we're interested in. */
107 nname = 0;
108 for (i = 1; i < symtabct; i++)
109 if (wantsym(&symtab[i], strtab))
110 nname++;
111
112 /* Allocate memory for them, plus a terminating entry. */
113 if ((nl = (nltype *)calloc(nname + 1, sizeof(nltype))) == NULL)
114 errx(1, "Insufficient memory for symbol table");
115
116 /* Read them in. */
117 npe = nl;
118 for (i = 1; i < symtabct; i++) {
119 const Elf_Sym *sym = &symtab[i];
120
121 if (wantsym(sym, strtab)) {
122 npe->value = sym->st_value;
123 npe->name = strtab + sym->st_name;
124 npe++;
125 }
126 }
127 npe->value = -1;
128
129 *defaultEs = excludes;
130 return 0;
131}
132
133static bool
134wantsym(const Elf_Sym *sym, const char *strtab)
135{
136 int type;
137 int bind;
138
139 type = ELF_ST_TYPE(sym->st_info);
140 bind = ELF_ST_BIND(sym->st_info);
141
142 if (type != STT_FUNC ||
143 (aflag && bind == STB_LOCAL) ||
144 (uflag && strchr(strtab + sym->st_name, '.') != NULL))
145 return 0;
146
147 return 1;
148}