1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
#!/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():
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)
# 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)
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()
""" 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)
|
