1 /* Test program for dwarf_next_cfi
2 Copyright (C) 2018 Red Hat, Inc.
3 This file is part of elfutils.
4
5 This file is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
9
10 elfutils is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
17
18 #include <config.h>
19 #include <assert.h>
20 #include <inttypes.h>
21 #include ELFUTILS_HEADER(dw)
22 #include <dwarf.h>
23 #include <argp.h>
24 #include <stdbool.h>
25 #include <stdio.h>
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <fcntl.h>
29 #include <locale.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33 #include "system.h"
34
35 void
handle_section(char * name,const unsigned char e_ident[],Elf_Scn * scn,const bool is_eh)36 handle_section (char *name, const unsigned char e_ident[],
37 Elf_Scn *scn, const bool is_eh)
38 {
39 if (is_eh)
40 printf (".eh_frame\n");
41 else
42 printf (".debug_frame\n");
43
44 GElf_Shdr mem;
45 GElf_Shdr *shdr = gelf_getshdr (scn, &mem);
46 if (shdr == NULL)
47 error (EXIT_FAILURE, 0, "Couldn't get section header: %s",
48 elf_errmsg (-1));
49 if ((shdr->sh_flags & SHF_COMPRESSED) != 0)
50 {
51 if (elf_compress (scn, 0, 0) < 0)
52 error (EXIT_FAILURE, 0, "Couldn't decompress section: %s",
53 elf_errmsg (-1));
54 }
55 else if (name[0] == '.' && name[1] == 'z')
56 {
57 if (elf_compress_gnu (scn, 0, 0) < 0)
58 error (EXIT_FAILURE, 0, "Couldn't decompress section: %s",
59 elf_errmsg (-1));
60 }
61
62 Elf_Data *data = elf_getdata (scn, NULL);
63 if (data == NULL || data->d_buf == NULL)
64 error (EXIT_FAILURE, 0, "no section data");
65
66 int res;
67 Dwarf_Off off;
68 Dwarf_Off next_off = 0;
69 Dwarf_CFI_Entry entry;
70 while ((res = dwarf_next_cfi (e_ident, data, is_eh, off = next_off,
71 &next_off, &entry)) == 0)
72 {
73 printf ("[%" PRId64 "] ", off);
74 if (dwarf_cfi_cie_p (&entry))
75 printf ("CIE augmentation=\"%s\"\n", entry.cie.augmentation);
76 else
77 {
78 printf ("FDE cie=[%" PRId64 "]\n", entry.fde.CIE_pointer);
79
80 Dwarf_Off cie_off = entry.fde.CIE_pointer;
81 Dwarf_Off cie_off_next;
82 Dwarf_CFI_Entry cie_entry;
83 if (dwarf_next_cfi (e_ident, data, is_eh, cie_off, &cie_off_next,
84 &cie_entry) != 0
85 || !dwarf_cfi_cie_p (&cie_entry))
86 error (EXIT_FAILURE, 0, "FDE doesn't point to CIE");
87 }
88 }
89
90 if (res < 0)
91 error (EXIT_FAILURE, 0, "dwarf_next_cfi failed: %s\n",
92 dwarf_errmsg (-1));
93 }
94
95 int
main(int argc,char * argv[])96 main (int argc, char *argv[])
97 {
98 if (argc != 2)
99 error (EXIT_FAILURE, 0, "need file name argument");
100
101 const char *file = argv[1];
102 printf ("%s\n", file);
103
104 int fd = open (file, O_RDONLY);
105 if (fd == -1)
106 error (EXIT_FAILURE, errno, "cannot open input file `%s'", file);
107
108 elf_version (EV_CURRENT);
109
110 Elf *elf = elf_begin (fd, ELF_C_READ, NULL);
111 if (elf == NULL)
112 error (EXIT_FAILURE, 0, "cannot create ELF descriptor: %s",
113 elf_errmsg (-1));
114
115 size_t esize;
116 const unsigned char *ident = (const unsigned char *) elf_getident (elf,
117 &esize);
118 if (ident == NULL || esize < EI_NIDENT)
119 error (EXIT_FAILURE, 0, "no, or too small, ELF ident");
120
121 GElf_Ehdr ehdr;
122 if (gelf_getehdr (elf, &ehdr) == NULL)
123 error (EXIT_FAILURE, 0, "cannot get the ELF header: %s\n",
124 elf_errmsg (-1));
125
126 size_t strndx = ehdr.e_shstrndx;
127
128 Elf_Scn *scn = NULL;
129 while ((scn = elf_nextscn (elf, scn)) != NULL)
130 {
131 GElf_Shdr shdr;
132 if (gelf_getshdr (scn, &shdr) != NULL)
133 {
134 char *name = elf_strptr (elf, strndx, (size_t) shdr.sh_name);
135 if (name != NULL && shdr.sh_type == SHT_PROGBITS)
136 {
137 if (strcmp (name, ".eh_frame") == 0)
138 handle_section (name, ident, scn, true);
139 if (strcmp (name, ".debug_frame") == 0
140 || strcmp (name, ".zdebug_frame") == 0)
141 handle_section (name, ident, scn, false);
142 }
143 }
144 }
145
146 elf_end (elf);
147 close (fd);
148
149 return 0;
150 }
151