1 /* Test program for elf_update function.
2 Copyright (C) 2000, 2002, 2005, 2016 Red Hat, Inc.
3 This file is part of elfutils.
4 Written by Ulrich Drepper <drepper@redhat.com>, 2000.
5
6 This file is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 elfutils is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18
19 #ifdef HAVE_CONFIG_H
20 # include <config.h>
21 #endif
22
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <libelf.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 #include "system.h"
31
32 #include ELFUTILS_HEADER(dwelf)
33
34
35 int
main(int argc,char * argv[])36 main (int argc, char *argv[] __attribute__ ((unused)))
37 {
38 const char *fname = "xxx_update3";
39 int fd;
40 Elf *elf;
41 Elf32_Ehdr *ehdr;
42 Elf32_Phdr *phdr;
43 Elf_Scn *scn;
44 Elf32_Shdr *shdr;
45 Elf_Data *data;
46 Dwelf_Strtab *shst;
47 Dwelf_Strent *shstrtabse;
48 int i;
49
50 fd = open (fname, O_RDWR | O_CREAT | O_TRUNC, DEFFILEMODE);
51 if (fd == -1)
52 {
53 printf ("cannot open `%s': %s\n", fname, strerror (errno));
54 exit (1);
55 }
56
57 elf_version (EV_CURRENT);
58
59 elf_fill (0x42);
60
61 elf = elf_begin (fd, ELF_C_WRITE, NULL);
62 if (elf == NULL)
63 {
64 printf ("cannot create ELF descriptor: %s\n", elf_errmsg (-1));
65 exit (1);
66 }
67
68 /* Create an ELF header. */
69 ehdr = elf32_newehdr (elf);
70 if (ehdr == NULL)
71 {
72 printf ("cannot create ELF header: %s\n", elf_errmsg (-1));
73 exit (1);
74 }
75
76 /* Print the ELF header values. */
77 if (argc > 1)
78 {
79 for (i = 0; i < EI_NIDENT; ++i)
80 printf (" %02x", ehdr->e_ident[i]);
81 printf ("\
82 \ntype = %hu\nmachine = %hu\nversion = %u\nentry = %u\nphoff = %u\n"
83 "shoff = %u\nflags = %u\nehsize = %hu\nphentsize = %hu\n"
84 "phnum = %hu\nshentsize = %hu\nshnum = %hu\nshstrndx = %hu\n",
85 ehdr->e_type, ehdr->e_machine, ehdr->e_version, ehdr->e_entry,
86 ehdr->e_phoff, ehdr->e_shoff, ehdr->e_flags, ehdr->e_ehsize,
87 ehdr->e_phentsize, ehdr->e_phnum, ehdr->e_shentsize,
88 ehdr->e_shnum, ehdr->e_shstrndx);
89 }
90
91 ehdr->e_ident[0] = 42;
92 ehdr->e_ident[4] = 1;
93 ehdr->e_ident[5] = 1;
94 ehdr->e_ident[6] = 2;
95 ehdr->e_type = ET_EXEC;
96 ehdr->e_version = 1;
97 ehdr->e_ehsize = 1;
98 elf_flagehdr (elf, ELF_C_SET, ELF_F_DIRTY);
99
100 /* Create the program header. */
101 phdr = elf32_newphdr (elf, 1);
102 if (phdr == NULL)
103 {
104 printf ("cannot create program header: %s\n", elf_errmsg (-1));
105 exit (1);
106 }
107
108 phdr[0].p_type = PT_PHDR;
109 elf_flagphdr (elf, ELF_C_SET, ELF_F_DIRTY);
110
111 shst = dwelf_strtab_init (true);
112
113 scn = elf_newscn (elf);
114 if (scn == NULL)
115 {
116 printf ("cannot create SHSTRTAB section: %s\n", elf_errmsg (-1));
117 exit (1);
118 }
119 shdr = elf32_getshdr (scn);
120 if (shdr == NULL)
121 {
122 printf ("cannot get header for SHSTRTAB section: %s\n", elf_errmsg (-1));
123 exit (1);
124 }
125
126 shstrtabse = dwelf_strtab_add (shst, ".shstrtab");
127
128 shdr->sh_type = SHT_STRTAB;
129 shdr->sh_flags = 0;
130 shdr->sh_addr = 0;
131 shdr->sh_link = SHN_UNDEF;
132 shdr->sh_info = SHN_UNDEF;
133 shdr->sh_addralign = 1;
134 shdr->sh_entsize = 0;
135
136 /* We have to store the section index in the ELF header. */
137 ehdr->e_shstrndx = elf_ndxscn (scn);
138
139 data = elf_newdata (scn);
140 if (data == NULL)
141 {
142 printf ("cannot create data SHSTRTAB section: %s\n", elf_errmsg (-1));
143 exit (1);
144 }
145
146 /* No more sections, finalize the section header string table. */
147 dwelf_strtab_finalize (shst, data);
148
149 shdr->sh_name = dwelf_strent_off (shstrtabse);
150
151 /* Let the library compute the internal structure information. */
152 if (elf_update (elf, ELF_C_NULL) < 0)
153 {
154 printf ("failure in elf_update(NULL): %s\n", elf_errmsg (-1));
155 exit (1);
156 }
157
158 ehdr = elf32_getehdr (elf);
159
160 phdr[0].p_offset = ehdr->e_phoff;
161 phdr[0].p_offset = ehdr->e_phoff;
162 phdr[0].p_vaddr = ehdr->e_phoff;
163 phdr[0].p_paddr = ehdr->e_phoff;
164 phdr[0].p_flags = PF_R | PF_X;
165 phdr[0].p_filesz = ehdr->e_phnum * elf32_fsize (ELF_T_PHDR, 1, EV_CURRENT);
166 phdr[0].p_memsz = ehdr->e_phnum * elf32_fsize (ELF_T_PHDR, 1, EV_CURRENT);
167 phdr[0].p_align = sizeof (Elf32_Word);
168
169 /* Write out the file. */
170 if (elf_update (elf, ELF_C_WRITE) < 0)
171 {
172 printf ("failure in elf_update(WRITE): %s\n", elf_errmsg (-1));
173 exit (1);
174 }
175
176 /* We don't need the string table anymore. */
177 dwelf_strtab_free (shst);
178
179 /* And the data allocated in the .shstrtab section. */
180 free (data->d_buf);
181
182 /* Print the ELF header values. */
183 if (argc > 1)
184 {
185 for (i = 0; i < EI_NIDENT; ++i)
186 printf (" %02x", ehdr->e_ident[i]);
187 printf ("\
188 \ntype = %hu\nmachine = %hu\nversion = %u\nentry = %u\nphoff = %u\n"
189 "shoff = %u\nflags = %u\nehsize = %hu\nphentsize = %hu\n"
190 "phnum = %hu\nshentsize = %hu\nshnum = %hu\nshstrndx = %hu\n",
191 ehdr->e_type, ehdr->e_machine, ehdr->e_version, ehdr->e_entry,
192 ehdr->e_phoff, ehdr->e_shoff, ehdr->e_flags, ehdr->e_ehsize,
193 ehdr->e_phentsize, ehdr->e_phnum, ehdr->e_shentsize,
194 ehdr->e_shnum, ehdr->e_shstrndx);
195 }
196
197 if (elf_end (elf) != 0)
198 {
199 printf ("failure in elf_end: %s\n", elf_errmsg (-1));
200 exit (1);
201 }
202
203 unlink (fname);
204
205 return 0;
206 }
207