1 /* Copyright (C) 1999-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published
6 by the Free Software Foundation; version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, see <https://www.gnu.org/licenses/>. */
17 /* The code in this file and in readelflib is a heavily simplified
18 version of the readelf program that's part of the current binutils
19 development version. Besides the simplification, it has also been
20 modified to read some other file formats. */
31 #include <sys/param.h>
33 #include <gnu/lib-names.h>
37 #define Elf32_CLASS ELFCLASS32
38 #define Elf64_CLASS ELFCLASS64
46 static struct known_names interpreters
[] =
48 { "/lib/" LD_SO
, FLAG_ELF_LIBC6
},
49 #ifdef SYSDEP_KNOWN_INTERPRETER_NAMES
50 SYSDEP_KNOWN_INTERPRETER_NAMES
54 static struct known_names known_libs
[] =
56 { LIBC_SO
, FLAG_ELF_LIBC6
},
57 { LIBM_SO
, FLAG_ELF_LIBC6
},
58 #ifdef SYSDEP_KNOWN_LIBRARY_NAMES
59 SYSDEP_KNOWN_LIBRARY_NAMES
64 /* Check if string corresponds to a GDB Python file. */
66 is_gdb_python_file (const char *name
)
68 size_t len
= strlen (name
);
69 return len
> 7 && strcmp (name
+ len
- 7, "-gdb.py") == 0;
72 /* Returns 0 if everything is ok, != 0 in case of error. */
74 process_file (const char *real_file_name
, const char *file_name
,
75 const char *lib
, int *flag
, unsigned int *osversion
,
76 unsigned int *isa_level
, char **soname
, int is_link
,
77 struct stat
*stat_buf
)
83 ElfW(Ehdr
) *elf_header
;
84 struct exec
*aout_header
;
90 file
= fopen (real_file_name
, "rb");
93 /* No error for stale symlink. */
94 if (is_link
&& strstr (file_name
, ".so") != NULL
)
96 error (0, 0, _("Input file %s not found.\n"), file_name
);
100 if (fstat (fileno (file
), &statbuf
) < 0)
102 error (0, 0, _("Cannot fstat file %s.\n"), file_name
);
107 /* Check that the file is large enough so that we can access the
108 information. We're only checking the size of the headers here. */
109 if ((size_t) statbuf
.st_size
< sizeof (struct exec
)
110 || (size_t) statbuf
.st_size
< sizeof (ElfW(Ehdr
)))
112 if (statbuf
.st_size
== 0)
113 error (0, 0, _("File %s is empty, not checked."), file_name
);
117 size_t n
= MIN (statbuf
.st_size
, SELFMAG
);
118 if (fread (buf
, n
, 1, file
) == 1 && memcmp (buf
, ELFMAG
, n
) == 0)
119 error (0, 0, _("File %s is too small, not checked."), file_name
);
125 file_contents
= mmap (0, statbuf
.st_size
, PROT_READ
, MAP_SHARED
,
127 if (file_contents
== MAP_FAILED
)
129 error (0, 0, _("Cannot mmap file %s.\n"), file_name
);
134 /* First check if this is an aout file. */
135 aout_header
= (struct exec
*) file_contents
;
136 if (N_MAGIC (*aout_header
) == ZMAGIC
137 #ifdef QMAGIC /* Linuxism. */
138 || N_MAGIC (*aout_header
) == QMAGIC
142 /* Aout files don't have a soname, just return the name
143 including the major number. */
144 char *copy
, *major
, *dot
;
145 copy
= xstrdup (lib
);
146 major
= strstr (copy
, ".so.");
149 dot
= strstr (major
+ 4, ".");
158 elf_header
= (ElfW(Ehdr
) *) file_contents
;
159 if (memcmp (elf_header
->e_ident
, ELFMAG
, SELFMAG
) != 0)
161 /* The file is neither ELF nor aout. Check if it's a linker
162 script, like libc.so - otherwise complain. Only search the
163 beginning of the file. */
164 size_t len
= MIN (statbuf
.st_size
, 512);
165 if (memmem (file_contents
, len
, "GROUP", 5) == NULL
166 && memmem (file_contents
, len
, "GNU ld script", 13) == NULL
167 && !is_gdb_python_file (file_name
))
168 error (0, 0, _("%s is not an ELF file - it has the wrong magic bytes at the start.\n"),
172 /* Libraries have to be shared object files. */
173 else if (elf_header
->e_type
!= ET_DYN
)
175 else if (process_elf_file (file_name
, lib
, flag
, osversion
, isa_level
,
176 soname
, file_contents
, statbuf
.st_size
))
180 /* Clean up allocated memory and resources. */
181 munmap (file_contents
, statbuf
.st_size
);
188 /* Returns made up soname if lib doesn't have explicit DT_SONAME. */
191 implicit_soname (const char *lib
, int flag
)
193 char *soname
= xstrdup (lib
);
195 if ((flag
& FLAG_TYPE_MASK
) != FLAG_LIBC4
)
198 /* Aout files don't have a soname, just return the name
199 including the major number. */
200 char *major
= strstr (soname
, ".so.");
203 char *dot
= strstr (major
+ 4, ".");
210 /* Get architecture specific version of process_elf_file. */
211 #include <readelflib.c>