1 #!/usr/bin/python2 2 """Diff 2 chromiumos images by comparing each elf file. 3 4 The script diffs every *ELF* files by dissembling every *executable* 5 section, which means it is not a FULL elf differ. 6 7 A simple usage example - 8 chromiumos_image_diff.py --image1 image-path-1 --image2 image-path-2 9 10 Note that image path should be inside the chroot, if not (ie, image is 11 downloaded from web), please specify a chromiumos checkout via 12 "--chromeos_root". 13 14 And this script should be executed outside chroot. 15 """ 16 17 from __future__ import print_function 18 19 __author__ = 'shenhan (at] google.com (Han Shen)' 20 21 import argparse 22 import os 23 import re 24 import sys 25 import tempfile 26 27 import image_chromeos 28 from cros_utils import command_executer 29 from cros_utils import logger 30 from cros_utils import misc 31 32 33 class CrosImage(object): 34 """A cros image object.""" 35 36 def __init__(self, image, chromeos_root, no_unmount): 37 self.image = image 38 self.chromeos_root = chromeos_root 39 self.mounted = False 40 self._ce = command_executer.GetCommandExecuter() 41 self.logger = logger.GetLogger() 42 self.elf_files = [] 43 self.no_unmount = no_unmount 44 self.unmount_script = '' 45 self.stateful = '' 46 self.rootfs = '' 47 48 def MountImage(self, mount_basename): 49 """Mount/unpack the image.""" 50 51 if mount_basename: 52 self.rootfs = '/tmp/{0}.rootfs'.format(mount_basename) 53 self.stateful = '/tmp/{0}.stateful'.format(mount_basename) 54 self.unmount_script = '/tmp/{0}.unmount.sh'.format(mount_basename) 55 else: 56 self.rootfs = tempfile.mkdtemp(suffix='.rootfs', 57 prefix='chromiumos_image_diff') 58 ## rootfs is like /tmp/tmpxyz012.rootfs. 59 match = re.match(r'^(.*)\.rootfs$', self.rootfs) 60 basename = match.group(1) 61 self.stateful = basename + '.stateful' 62 os.mkdir(self.stateful) 63 self.unmount_script = '{0}.unmount.sh'.format(basename) 64 65 self.logger.LogOutput('Mounting "{0}" onto "{1}" and "{2}"'.format( 66 self.image, self.rootfs, self.stateful)) 67 ## First of all creating an unmount image 68 self.CreateUnmountScript() 69 command = image_chromeos.GetImageMountCommand( 70 self.chromeos_root, self.image, self.rootfs, self.stateful) 71 rv = self._ce.RunCommand(command, print_to_console=True) 72 self.mounted = (rv == 0) 73 if not self.mounted: 74 self.logger.LogError('Failed to mount "{0}" onto "{1}" and "{2}".'.format( 75 self.image, self.rootfs, self.stateful)) 76 return self.mounted 77 78 def CreateUnmountScript(self): 79 command = ('sudo umount {r}/usr/local {r}/usr/share/oem ' 80 '{r}/var {r}/mnt/stateful_partition {r}; sudo umount {s} ; ' 81 'rmdir {r} ; rmdir {s}\n').format(r=self.rootfs, s=self.stateful) 82 f = open(self.unmount_script, 'w') 83 f.write(command) 84 f.close() 85 self._ce.RunCommand('chmod +x {}'.format(self.unmount_script), 86 print_to_console=False) 87 self.logger.LogOutput('Created an unmount script - "{0}"'.format( 88 self.unmount_script)) 89 90 def UnmountImage(self): 91 """Unmount the image and delete mount point.""" 92 93 self.logger.LogOutput('Unmounting image "{0}" from "{1}" and "{2}"'.format( 94 self.image, self.rootfs, self.stateful)) 95 if self.mounted: 96 command = 'bash "{0}"'.format(self.unmount_script) 97 if self.no_unmount: 98 self.logger.LogOutput(('Please unmount manually - \n' 99 '\t bash "{0}"'.format(self.unmount_script))) 100 else: 101 if self._ce.RunCommand(command, print_to_console=True) == 0: 102 self._ce.RunCommand('rm {0}'.format(self.unmount_script)) 103 self.mounted = False 104 self.rootfs = None 105 self.stateful = None 106 self.unmount_script = None 107 108 return not self.mounted 109 110 def FindElfFiles(self): 111 """Find all elf files for the image. 112 113 Returns: 114 Always true 115 """ 116 117 self.logger.LogOutput('Finding all elf files in "{0}" ...'.format( 118 self.rootfs)) 119 # Note '\;' must be prefixed by 'r'. 120 command = ('find "{0}" -type f -exec ' 121 'bash -c \'file -b "{{}}" | grep -q "ELF"\'' r' \; ' 122 r'-exec echo "{{}}" \;').format(self.rootfs) 123 self.logger.LogCmd(command) 124 _, out, _ = self._ce.RunCommandWOutput(command, print_to_console=False) 125 self.elf_files = out.splitlines() 126 self.logger.LogOutput( 127 'Total {0} elf files found.'.format(len(self.elf_files))) 128 return True 129 130 131 class ImageComparator(object): 132 """A class that wraps comparsion actions.""" 133 134 def __init__(self, images, diff_file): 135 self.images = images 136 self.logger = logger.GetLogger() 137 self.diff_file = diff_file 138 self.tempf1 = None 139 self.tempf2 = None 140 141 def Cleanup(self): 142 if self.tempf1 and self.tempf2: 143 command_executer.GetCommandExecuter().RunCommand( 144 'rm {0} {1}'.format(self.tempf1, self.tempf2)) 145 logger.GetLogger('Removed "{0}" and "{1}".'.format( 146 self.tempf1, self.tempf2)) 147 148 def CheckElfFileSetEquality(self): 149 """Checking whether images have exactly number of elf files.""" 150 151 self.logger.LogOutput('Checking elf file equality ...') 152 i1 = self.images[0] 153 i2 = self.images[1] 154 t1 = i1.rootfs + '/' 155 elfset1 = set([e.replace(t1, '') for e in i1.elf_files]) 156 t2 = i2.rootfs + '/' 157 elfset2 = set([e.replace(t2, '') for e in i2.elf_files]) 158 dif1 = elfset1.difference(elfset2) 159 msg = None 160 if dif1: 161 msg = 'The following files are not in "{image}" - "{rootfs}":\n'.format( 162 image=i2.image, rootfs=i2.rootfs) 163 for d in dif1: 164 msg += '\t' + d + '\n' 165 dif2 = elfset2.difference(elfset1) 166 if dif2: 167 msg = 'The following files are not in "{image}" - "{rootfs}":\n'.format( 168 image=i1.image, rootfs=i1.rootfs) 169 for d in dif2: 170 msg += '\t' + d + '\n' 171 if msg: 172 self.logger.LogError(msg) 173 return False 174 return True 175 176 def CompareImages(self): 177 """Do the comparsion work.""" 178 179 if not self.CheckElfFileSetEquality(): 180 return False 181 182 mismatch_list = [] 183 match_count = 0 184 i1 = self.images[0] 185 i2 = self.images[1] 186 self.logger.LogOutput('Start comparing {0} elf file by file ...'.format( 187 len(i1.elf_files))) 188 ## Note - i1.elf_files and i2.elf_files have exactly the same entries here. 189 190 ## Create 2 temp files to be used for all disassembed files. 191 handle, self.tempf1 = tempfile.mkstemp() 192 os.close(handle) # We do not need the handle 193 handle, self.tempf2 = tempfile.mkstemp() 194 os.close(handle) 195 196 cmde = command_executer.GetCommandExecuter() 197 for elf1 in i1.elf_files: 198 tmp_rootfs = i1.rootfs + '/' 199 f1 = elf1.replace(tmp_rootfs, '') 200 full_path1 = elf1 201 full_path2 = elf1.replace(i1.rootfs, i2.rootfs) 202 203 if full_path1 == full_path2: 204 self.logger.LogError( 205 'Error: We\'re comparing the SAME file - {0}'.format(f1)) 206 continue 207 208 command = ('objdump -d "{f1}" > {tempf1} ; ' 209 'objdump -d "{f2}" > {tempf2} ; ' 210 # Remove path string inside the dissemble 211 'sed -i \'s!{rootfs1}!!g\' {tempf1} ; ' 212 'sed -i \'s!{rootfs2}!!g\' {tempf2} ; ' 213 'diff {tempf1} {tempf2} 1>/dev/null 2>&1').format( 214 f1=full_path1, f2=full_path2, 215 rootfs1=i1.rootfs, rootfs2=i2.rootfs, 216 tempf1=self.tempf1, tempf2=self.tempf2) 217 ret = cmde.RunCommand(command, print_to_console=False) 218 if ret != 0: 219 self.logger.LogOutput('*** Not match - "{0}" "{1}"'.format( 220 full_path1, full_path2)) 221 mismatch_list.append(f1) 222 if self.diff_file: 223 command = ( 224 'echo "Diffs of disassemble of \"{f1}\" and \"{f2}\"" ' 225 '>> {diff_file} ; diff {tempf1} {tempf2} ' 226 '>> {diff_file}').format( 227 f1=full_path1, f2=full_path2, diff_file=self.diff_file, 228 tempf1=self.tempf1, tempf2=self.tempf2) 229 cmde.RunCommand(command, print_to_console=False) 230 else: 231 match_count += 1 232 ## End of comparing every elf files. 233 234 if not mismatch_list: 235 self.logger.LogOutput('** COOL, ALL {0} BINARIES MATCHED!! **'.format( 236 match_count)) 237 return True 238 239 mismatch_str = 'Found {0} mismatch:\n'.format(len(mismatch_list)) 240 for b in mismatch_list: 241 mismatch_str += '\t' + b + '\n' 242 243 self.logger.LogOutput(mismatch_str) 244 return False 245 246 247 def Main(argv): 248 """The main function.""" 249 250 command_executer.InitCommandExecuter() 251 images = [] 252 253 parser = argparse.ArgumentParser() 254 parser.add_argument( 255 '--no_unmount', action='store_true', dest='no_unmount', default=False, 256 help='Do not unmount after finish, this is useful for debugging.') 257 parser.add_argument( 258 '--chromeos_root', dest='chromeos_root', default=None, action='store', 259 help=('[Optional] Specify a chromeos tree instead of ' 260 'deducing it from image path so that we can compare ' 261 '2 images that are downloaded.')) 262 parser.add_argument( 263 '--mount_basename', dest='mount_basename', default=None, action='store', 264 help=('Specify a meaningful name for the mount point. With this being ' 265 'set, the mount points would be "/tmp/mount_basename.x.rootfs" ' 266 ' and "/tmp/mount_basename.x.stateful". (x is 1 or 2).')) 267 parser.add_argument('--diff_file', dest='diff_file', default=None, 268 help='Dumping all the diffs (if any) to the diff file') 269 parser.add_argument('--image1', dest='image1', default=None, 270 required=True, help=('Image 1 file name.')) 271 parser.add_argument('--image2', dest='image2', default=None, 272 required=True, help=('Image 2 file name.')) 273 options = parser.parse_args(argv[1:]) 274 275 if options.mount_basename and options.mount_basename.find('/') >= 0: 276 logger.GetLogger().LogError( 277 '"--mount_basename" must be a name, not a path.') 278 parser.print_help() 279 return 1 280 281 result = False 282 image_comparator = None 283 try: 284 for i, image_path in enumerate([options.image1, options.image2], start=1): 285 image_path = os.path.realpath(image_path) 286 if not os.path.isfile(image_path): 287 logger.getLogger().LogError('"{0}" is not a file.'.format(image_path)) 288 return 1 289 290 chromeos_root = None 291 if options.chromeos_root: 292 chromeos_root = options.chromeos_root 293 else: 294 ## Deduce chromeos root from image 295 t = image_path 296 while t != '/': 297 if misc.IsChromeOsTree(t): 298 break 299 t = os.path.dirname(t) 300 if misc.IsChromeOsTree(t): 301 chromeos_root = t 302 303 if not chromeos_root: 304 logger.GetLogger().LogError( 305 'Please provide a valid chromeos root via --chromeos_root') 306 return 1 307 308 image = CrosImage(image_path, chromeos_root, options.no_unmount) 309 310 if options.mount_basename: 311 mount_basename = '{basename}.{index}'.format( 312 basename=options.mount_basename, index=i) 313 else: 314 mount_basename = None 315 316 if image.MountImage(mount_basename): 317 images.append(image) 318 image.FindElfFiles() 319 320 if len(images) == 2: 321 image_comparator = ImageComparator(images, options.diff_file) 322 result = image_comparator.CompareImages() 323 finally: 324 for image in images: 325 image.UnmountImage() 326 if image_comparator: 327 image_comparator.Cleanup() 328 329 return 0 if result else 1 330 331 332 if __name__ == '__main__': 333 Main(sys.argv) 334
