glibc/elf/readlib.c
H.J. Lu eea3dc5bf2 Don't issue errors on GDB Python files
Many packages, including GCC, install Python files for GDB in library
diretory. ldconfig reads them and issue errors since they aren't ELF
files:

ldconfig: /usr/gcc-5.1.1/lib/libstdc++.so.6.0.21-gdb.py is not an ELF file - it has the wrong magic bytes at the start.

ldconfig: /usr/gcc-5.1.1/libx32/libstdc++.so.6.0.21-gdb.py is not an ELF file - it has the wrong magic bytes at the start.

ldconfig: /usr/gcc-5.1.1/lib64/libstdc++.so.6.0.21-gdb.py is not an ELF file - it has the wrong magic bytes at the start.

This patch silences ldconfig on GDB Python files by checking filenames
with -gdb.py suffix.

	[BZ #18585]
	* elf/readlib.c (is_gdb_python_file): New.
	(process_file): Don't issue errors on filenames with -gdb.py
	suffix.
2015-06-24 10:27:39 -07:00

213 lines
5.7 KiB
C

/* Copyright (C) 1999-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Andreas Jaeger <aj@suse.de>, 1999 and
Jakub Jelinek <jakub@redhat.com>, 1999.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>. */
/* The code in this file and in readelflib is a heavily simplified
version of the readelf program that's part of the current binutils
development version. Besides the simplification, it has also been
modified to read some other file formats. */
#include <a.out.h>
#include <elf.h>
#include <error.h>
#include <libintl.h>
#include <link.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <gnu/lib-names.h>
#include <ldconfig.h>
#define Elf32_CLASS ELFCLASS32
#define Elf64_CLASS ELFCLASS64
struct known_names
{
const char *soname;
int flag;
};
static struct known_names interpreters[] =
{
{ "/lib/" LD_SO, FLAG_ELF_LIBC6 },
#ifdef SYSDEP_KNOWN_INTERPRETER_NAMES
SYSDEP_KNOWN_INTERPRETER_NAMES
#endif
};
static struct known_names known_libs[] =
{
{ LIBC_SO, FLAG_ELF_LIBC6 },
{ LIBM_SO, FLAG_ELF_LIBC6 },
#ifdef SYSDEP_KNOWN_LIBRARY_NAMES
SYSDEP_KNOWN_LIBRARY_NAMES
#endif
};
/* Check if string corresponds to a GDB Python file. */
static bool
is_gdb_python_file (const char *name)
{
size_t len = strlen (name);
return len > 7 && strcmp (name + len - 7, "-gdb.py") == 0;
}
/* Returns 0 if everything is ok, != 0 in case of error. */
int
process_file (const char *real_file_name, const char *file_name,
const char *lib, int *flag, unsigned int *osversion,
char **soname, int is_link, struct stat64 *stat_buf)
{
FILE *file;
struct stat64 statbuf;
void *file_contents;
int ret;
ElfW(Ehdr) *elf_header;
struct exec *aout_header;
ret = 0;
*flag = FLAG_ANY;
*soname = NULL;
file = fopen (real_file_name, "rb");
if (file == NULL)
{
/* No error for stale symlink. */
if (is_link && strstr (file_name, ".so") != NULL)
return 1;
error (0, 0, _("Input file %s not found.\n"), file_name);
return 1;
}
if (fstat64 (fileno (file), &statbuf) < 0)
{
error (0, 0, _("Cannot fstat file %s.\n"), file_name);
fclose (file);
return 1;
}
/* Check that the file is large enough so that we can access the
information. We're only checking the size of the headers here. */
if ((size_t) statbuf.st_size < sizeof (struct exec)
|| (size_t) statbuf.st_size < sizeof (ElfW(Ehdr)))
{
if (statbuf.st_size == 0)
error (0, 0, _("File %s is empty, not checked."), file_name);
else
{
char buf[SELFMAG];
size_t n = MIN (statbuf.st_size, SELFMAG);
if (fread (buf, n, 1, file) == 1 && memcmp (buf, ELFMAG, n) == 0)
error (0, 0, _("File %s is too small, not checked."), file_name);
}
fclose (file);
return 1;
}
file_contents = mmap (0, statbuf.st_size, PROT_READ, MAP_SHARED,
fileno (file), 0);
if (file_contents == MAP_FAILED)
{
error (0, 0, _("Cannot mmap file %s.\n"), file_name);
fclose (file);
return 1;
}
/* First check if this is an aout file. */
aout_header = (struct exec *) file_contents;
if (N_MAGIC (*aout_header) == ZMAGIC
#ifdef QMAGIC /* Linuxism. */
|| N_MAGIC (*aout_header) == QMAGIC
#endif
)
{
/* Aout files don't have a soname, just return the name
including the major number. */
char *copy, *major, *dot;
copy = xstrdup (lib);
major = strstr (copy, ".so.");
if (major)
{
dot = strstr (major + 4, ".");
if (dot)
*dot = '\0';
}
*soname = copy;
*flag = FLAG_LIBC4;
goto done;
}
elf_header = (ElfW(Ehdr) *) file_contents;
if (memcmp (elf_header->e_ident, ELFMAG, SELFMAG) != 0)
{
/* The file is neither ELF nor aout. Check if it's a linker
script, like libc.so - otherwise complain. Only search the
beginning of the file. */
size_t len = MIN (statbuf.st_size, 512);
if (memmem (file_contents, len, "GROUP", 5) == NULL
&& memmem (file_contents, len, "GNU ld script", 13) == NULL
&& !is_gdb_python_file (file_name))
error (0, 0, _("%s is not an ELF file - it has the wrong magic bytes at the start.\n"),
file_name);
ret = 1;
}
/* Libraries have to be shared object files. */
else if (elf_header->e_type != ET_DYN)
ret = 1;
else if (process_elf_file (file_name, lib, flag, osversion, soname,
file_contents, statbuf.st_size))
ret = 1;
done:
/* Clean up allocated memory and resources. */
munmap (file_contents, statbuf.st_size);
fclose (file);
*stat_buf = statbuf;
return ret;
}
/* Returns made up soname if lib doesn't have explicit DT_SONAME. */
char *
implicit_soname (const char *lib, int flag)
{
char *soname = xstrdup (lib);
if ((flag & FLAG_TYPE_MASK) != FLAG_LIBC4)
return soname;
/* Aout files don't have a soname, just return the name
including the major number. */
char *major = strstr (soname, ".so.");
if (major)
{
char *dot = strstr (major + 4, ".");
if (dot)
*dot = '\0';
}
return soname;
}
/* Get architecture specific version of process_elf_file. */
#include <readelflib.c>