poky/scripts/relocate_sdk.py
Juro Bystricky 4dde12f17b relocate_sdk: additional error checks
When installing SDK in a non-default location and the path length
of the SDK install location is longer than the path length of the
default SDK location, relocation of .ldsochache section will overwrite
file location outside of the .ldsocache section size.
In addition, additional checks were added to ensure that any
path in sections .gccrelocprefix and .ldsochache will not exceed
the space allocated for it within the file, which would also result
in file corruption.

[YOCTO #9268]

(From OE-Core rev: 4d949da965a99ab33798af49e5584c8bb9f0f626)

Signed-off-by: Juro Bystricky <juro.bystricky@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2016-03-31 23:01:37 +01:00

265 lines
8.9 KiB
Python
Executable File

#!/usr/bin/env python
#
# Copyright (c) 2012 Intel Corporation
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# 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, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# DESCRIPTION
# This script is called by the SDK installer script. It replaces the dynamic
# loader path in all binaries and also fixes the SYSDIR paths/lengths and the
# location of ld.so.cache in the dynamic loader binary
#
# AUTHORS
# Laurentiu Palcu <laurentiu.palcu@intel.com>
#
import struct
import sys
import stat
import os
import re
import errno
if sys.version < '3':
def b(x):
return x
else:
def b(x):
return x.encode(sys.getfilesystemencoding())
old_prefix = re.compile(b("##DEFAULT_INSTALL_DIR##"))
def get_arch():
f.seek(0)
e_ident =f.read(16)
ei_mag0,ei_mag1_3,ei_class = struct.unpack("<B3sB11x", e_ident)
if (ei_mag0 != 0x7f and ei_mag1_3 != "ELF") or ei_class == 0:
return 0
if ei_class == 1:
return 32
elif ei_class == 2:
return 64
def parse_elf_header():
global e_type, e_machine, e_version, e_entry, e_phoff, e_shoff, e_flags,\
e_ehsize, e_phentsize, e_phnum, e_shentsize, e_shnum, e_shstrndx
f.seek(0)
elf_header = f.read(64)
if arch == 32:
# 32bit
hdr_fmt = "<HHILLLIHHHHHH"
hdr_size = 52
else:
# 64bit
hdr_fmt = "<HHIQQQIHHHHHH"
hdr_size = 64
e_type, e_machine, e_version, e_entry, e_phoff, e_shoff, e_flags,\
e_ehsize, e_phentsize, e_phnum, e_shentsize, e_shnum, e_shstrndx =\
struct.unpack(hdr_fmt, elf_header[16:hdr_size])
def change_interpreter(elf_file_name):
if arch == 32:
ph_fmt = "<IIIIIIII"
else:
ph_fmt = "<IIQQQQQQ"
""" look for PT_INTERP section """
for i in range(0,e_phnum):
f.seek(e_phoff + i * e_phentsize)
ph_hdr = f.read(e_phentsize)
if arch == 32:
# 32bit
p_type, p_offset, p_vaddr, p_paddr, p_filesz,\
p_memsz, p_flags, p_align = struct.unpack(ph_fmt, ph_hdr)
else:
# 64bit
p_type, p_flags, p_offset, p_vaddr, p_paddr, \
p_filesz, p_memsz, p_align = struct.unpack(ph_fmt, ph_hdr)
""" change interpreter """
if p_type == 3:
# PT_INTERP section
f.seek(p_offset)
# External SDKs with mixed pre-compiled binaries should not get
# relocated so look for some variant of /lib
fname = f.read(11)
if fname.startswith(b("/lib/")) or fname.startswith(b("/lib64/")) or \
fname.startswith(b("/lib32/")) or fname.startswith(b("/usr/lib32/")) or \
fname.startswith(b("/usr/lib32/")) or fname.startswith(b("/usr/lib64/")):
break
if (len(new_dl_path) >= p_filesz):
print("ERROR: could not relocate %s, interp size = %i and %i is needed." \
% (elf_file_name, p_memsz, len(new_dl_path) + 1))
break
dl_path = new_dl_path + b("\0") * (p_filesz - len(new_dl_path))
f.seek(p_offset)
f.write(dl_path)
break
def change_dl_sysdirs(elf_file_name):
if arch == 32:
sh_fmt = "<IIIIIIIIII"
else:
sh_fmt = "<IIQQQQIIQQ"
""" read section string table """
f.seek(e_shoff + e_shstrndx * e_shentsize)
sh_hdr = f.read(e_shentsize)
if arch == 32:
sh_offset, sh_size = struct.unpack("<16xII16x", sh_hdr)
else:
sh_offset, sh_size = struct.unpack("<24xQQ24x", sh_hdr)
f.seek(sh_offset)
sh_strtab = f.read(sh_size)
sysdirs = sysdirs_len = ""
""" change ld.so.cache path and default libs path for dynamic loader """
for i in range(0,e_shnum):
f.seek(e_shoff + i * e_shentsize)
sh_hdr = f.read(e_shentsize)
sh_name, sh_type, sh_flags, sh_addr, sh_offset, sh_size, sh_link,\
sh_info, sh_addralign, sh_entsize = struct.unpack(sh_fmt, sh_hdr)
name = sh_strtab[sh_name:sh_strtab.find(b("\0"), sh_name)]
""" look only into SHT_PROGBITS sections """
if sh_type == 1:
f.seek(sh_offset)
""" default library paths cannot be changed on the fly because """
""" the string lengths have to be changed too. """
if name == b(".sysdirs"):
sysdirs = f.read(sh_size)
sysdirs_off = sh_offset
sysdirs_sect_size = sh_size
elif name == b(".sysdirslen"):
sysdirslen = f.read(sh_size)
sysdirslen_off = sh_offset
elif name == b(".ldsocache"):
ldsocache_path = f.read(sh_size)
new_ldsocache_path = old_prefix.sub(new_prefix, ldsocache_path)
new_ldsocache_path = new_ldsocache_path.rstrip(b("\0"))
if (len(new_ldsocache_path) >= sh_size):
print("ERROR: could not relocate %s, .ldsocache section size = %i and %i is needed." \
% (elf_file_name, sh_size, len(new_ldsocache_path)))
sys.exit(-1)
# pad with zeros
new_ldsocache_path += b("\0") * (sh_size - len(new_ldsocache_path))
# write it back
f.seek(sh_offset)
f.write(new_ldsocache_path)
elif name == b(".gccrelocprefix"):
offset = 0
while (offset + 4096) <= sh_size:
path = f.read(4096)
new_path = old_prefix.sub(new_prefix, path)
new_path = new_path.rstrip(b("\0"))
if (len(new_path) >= 4096):
print("ERROR: could not relocate %s, max path size = 4096 and %i is needed." \
% (elf_file_name, len(new_path)))
sys.exit(-1)
# pad with zeros
new_path += b("\0") * (4096 - len(new_path))
#print "Changing %s to %s at %s" % (str(path), str(new_path), str(offset))
# write it back
f.seek(sh_offset + offset)
f.write(new_path)
offset = offset + 4096
if sysdirs != "" and sysdirslen != "":
paths = sysdirs.split(b("\0"))
sysdirs = b("")
sysdirslen = b("")
for path in paths:
""" exit the loop when we encounter first empty string """
if path == b(""):
break
new_path = old_prefix.sub(new_prefix, path)
sysdirs += new_path + b("\0")
if arch == 32:
sysdirslen += struct.pack("<L", len(new_path))
else:
sysdirslen += struct.pack("<Q", len(new_path))
""" pad with zeros """
sysdirs += b("\0") * (sysdirs_sect_size - len(sysdirs))
""" write the sections back """
f.seek(sysdirs_off)
f.write(sysdirs)
f.seek(sysdirslen_off)
f.write(sysdirslen)
# MAIN
if len(sys.argv) < 4:
sys.exit(-1)
# In python > 3, strings may also contain Unicode characters. So, convert
# them to bytes
if sys.version_info < (3,):
new_prefix = sys.argv[1]
new_dl_path = sys.argv[2]
else:
new_prefix = sys.argv[1].encode()
new_dl_path = sys.argv[2].encode()
executables_list = sys.argv[3:]
for e in executables_list:
perms = os.stat(e)[stat.ST_MODE]
if os.access(e, os.W_OK|os.R_OK):
perms = None
else:
os.chmod(e, perms|stat.S_IRWXU)
try:
f = open(e, "r+b")
except IOError:
exctype, ioex = sys.exc_info()[:2]
if ioex.errno == errno.ETXTBSY:
print("Could not open %s. File used by another process.\nPlease "\
"make sure you exit all processes that might use any SDK "\
"binaries." % e)
else:
print("Could not open %s: %s(%d)" % (e, ioex.strerror, ioex.errno))
sys.exit(-1)
# Save old size and do a size check at the end. Just a safety measure.
old_size = os.path.getsize(e)
if old_size >= 64:
arch = get_arch()
if arch:
parse_elf_header()
change_interpreter(e)
change_dl_sysdirs(e)
""" change permissions back """
if perms:
os.chmod(e, perms)
f.close()
if old_size != os.path.getsize(e):
print("New file size for %s is different. Looks like a relocation error!", e)
sys.exit(-1)