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