releasetools: Raise on image building errors.

The image building functions in build_image.py have been returning
(success, result) or special values to indicate the validity of the
result. The same logic can be better expressed by raising exceptions
instead, because
 a) using a special value relies on caller to check for that magic
    value;
 b) exceptions can carry additional messages other than a boolean does,
    e.g. the output from the failing command;
 c) caller can have cleaner code flow without explicitly checking for
    the validity of the result.

This CL changes such functions to raise on errors. The majority of these
functions are internal to build_image.py only, except for BuildImage()
that has a few callers in add_img_to_target_files.py (which all die upon
error anyway).

Test: `m dist`
Test: python -m unittest test_build_image
Test: python -m unittest test_add_img_to_target_files
Test: python -m unittest test_validate_target_files
Test: Inject an error to the depended binaries (e.g. avbtool), and check
      that build_image.py exits with error messages.
Change-Id: Ibe4d51e267756bb1a00fa9238a213f9d55fd9b58
This commit is contained in:
Tao Bao 2018-09-27 16:58:00 -07:00
parent 943be51cf1
commit c6bd70a5e6
4 changed files with 146 additions and 163 deletions

View file

@ -308,9 +308,8 @@ def CreateImage(input_dir, info_dict, what, output_file, block_list=None):
hash_seed = "hash_seed-" + uuid_seed
image_props["hash_seed"] = str(uuid.uuid5(uuid.NAMESPACE_URL, hash_seed))
succ = build_image.BuildImage(os.path.join(input_dir, what.upper()),
image_props, output_file.name)
assert succ, "build " + what + ".img image failed"
build_image.BuildImage(
os.path.join(input_dir, what.upper()), image_props, output_file.name)
output_file.Write()
if block_list:
@ -361,8 +360,7 @@ def AddUserdata(output_zip):
fstab = OPTIONS.info_dict["fstab"]
if fstab:
image_props["fs_type"] = fstab["/data"].fs_type
succ = build_image.BuildImage(user_dir, image_props, img.name)
assert succ, "build userdata.img image failed"
build_image.BuildImage(user_dir, image_props, img.name)
common.CheckSize(img.name, "userdata.img", OPTIONS.info_dict)
img.Write()
@ -514,8 +512,7 @@ def AddCache(output_zip):
fstab = OPTIONS.info_dict["fstab"]
if fstab:
image_props["fs_type"] = fstab["/cache"].fs_type
succ = build_image.BuildImage(user_dir, image_props, img.name)
assert succ, "build cache.img image failed"
build_image.BuildImage(user_dir, image_props, img.name)
common.CheckSize(img.name, "cache.img", OPTIONS.info_dict)
img.Write()

View file

@ -45,6 +45,13 @@ BLOCK_SIZE = 4096
BYTES_IN_MB = 1024 * 1024
class BuildImageError(Exception):
"""An Exception raised during image building."""
def __init__(self, message):
Exception.__init__(self, message)
def RunCommand(cmd, verbose=None, env=None):
"""Echo and run the given command.
@ -76,58 +83,55 @@ def GetVerityFECSize(partition_size):
cmd = ["fec", "-s", str(partition_size)]
output, exit_code = RunCommand(cmd, False)
if exit_code != 0:
return False, 0
return True, int(output)
raise BuildImageError("Failed to GetVerityFECSize:\n{}".format(output))
return int(output)
def GetVerityTreeSize(partition_size):
cmd = ["build_verity_tree", "-s", str(partition_size)]
output, exit_code = RunCommand(cmd, False)
if exit_code != 0:
return False, 0
return True, int(output)
raise BuildImageError("Failed to GetVerityTreeSize:\n{}".format(output))
return int(output)
def GetVerityMetadataSize(partition_size):
cmd = ["build_verity_metadata.py", "size", str(partition_size)]
output, exit_code = RunCommand(cmd, False)
if exit_code != 0:
return False, 0
return True, int(output)
raise BuildImageError("Failed to GetVerityMetadataSize:\n{}".format(output))
return int(output)
def GetVeritySize(partition_size, fec_supported):
success, verity_tree_size = GetVerityTreeSize(partition_size)
if not success:
return 0
success, verity_metadata_size = GetVerityMetadataSize(partition_size)
if not success:
return 0
verity_tree_size = GetVerityTreeSize(partition_size)
verity_metadata_size = GetVerityMetadataSize(partition_size)
verity_size = verity_tree_size + verity_metadata_size
if fec_supported:
success, fec_size = GetVerityFECSize(partition_size + verity_size)
if not success:
return 0
fec_size = GetVerityFECSize(partition_size + verity_size)
return verity_size + fec_size
return verity_size
def GetDiskUsage(path):
"""Return number of bytes that "path" occupies on host.
"""Returns the number of bytes that "path" occupies on host.
Args:
path: The directory or file to calculate size on
Returns:
True and the number of bytes if successful,
False and 0 otherwise.
The number of bytes.
Raises:
BuildImageError: On error.
"""
env = {"POSIXLY_CORRECT": "1"}
cmd = ["du", "-s", path]
output, exit_code = RunCommand(cmd, verbose=False, env=env)
if exit_code != 0:
return False, 0
raise BuildImageError("Failed to get disk usage:\n{}".format(output))
# POSIX du returns number of blocks with block size 512
return True, int(output.split()[0]) * 512
return int(output.split()[0]) * 512
def GetSimgSize(image_file):
@ -153,17 +157,24 @@ def AVBCalcMaxImageSize(avbtool, footer_type, partition_size, additional_args):
or "avbtool add_hashtree_footer".
Returns:
The maximum image size or 0 if an error occurred.
The maximum image size.
Raises:
BuildImageError: On error or getting invalid image size.
"""
cmd = [avbtool, "add_%s_footer" % footer_type,
"--partition_size", str(partition_size), "--calc_max_image_size"]
cmd.extend(shlex.split(additional_args))
(output, exit_code) = RunCommand(cmd)
output, exit_code = RunCommand(cmd)
if exit_code != 0:
return 0
else:
return int(output)
raise BuildImageError(
"Failed to calculate max image size:\n{}".format(output))
image_size = int(output)
if image_size <= 0:
raise BuildImageError(
"Invalid max image size: {}".format(output))
return image_size
def AVBCalcMinPartitionSize(image_size, size_calculator):
@ -240,8 +251,8 @@ def AVBAddFooter(image_path, avbtool, footer_type, partition_size,
additional_args: Additional arguments to pass to "avbtool add_hash_footer"
or "avbtool add_hashtree_footer".
Returns:
True if the operation succeeded.
Raises:
BuildImageError: On error.
"""
cmd = [avbtool, "add_%s_footer" % footer_type,
"--partition_size", partition_size,
@ -257,9 +268,8 @@ def AVBAddFooter(image_path, avbtool, footer_type, partition_size,
output, exit_code = RunCommand(cmd)
if exit_code != 0:
print("Failed to add AVB footer! Error: %s" % output)
return False
return True
raise BuildImageError(
"Failed to add AVB footer:\n{}".format(output))
def AdjustPartitionSizeForVerity(partition_size, fec_supported):
@ -316,9 +326,8 @@ def BuildVerityFEC(sparse_image_path, verity_path, verity_fec_path,
verity_path, verity_fec_path]
output, exit_code = RunCommand(cmd)
if exit_code != 0:
print("Could not build FEC data! Error: %s" % output)
return False
return True
raise BuildImageError(
"Failed to build FEC data:\n{}".format(output))
def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict):
@ -326,12 +335,11 @@ def BuildVerityTree(sparse_image_path, verity_image_path, prop_dict):
verity_image_path]
output, exit_code = RunCommand(cmd)
if exit_code != 0:
print("Could not build verity tree! Error: %s" % output)
return False
raise BuildImageError(
"Failed to build verity tree:\n{}".format(output))
root, salt = output.split()
prop_dict["verity_root_hash"] = root
prop_dict["verity_salt"] = salt
return True
def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
@ -345,9 +353,8 @@ def BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
cmd.append("--verity_disable")
output, exit_code = RunCommand(cmd)
if exit_code != 0:
print("Could not build verity metadata! Error: %s" % output)
return False
return True
raise BuildImageError(
"Failed to build verity metadata:\n{}".format(output))
def Append2Simg(sparse_image_path, unsparse_image_path, error_message):
@ -356,49 +363,45 @@ def Append2Simg(sparse_image_path, unsparse_image_path, error_message):
Args:
sparse_image_path: the path to the (sparse) image
unsparse_image_path: the path to the (unsparse) image
Returns:
True on success, False on failure.
Raises:
BuildImageError: On error.
"""
cmd = ["append2simg", sparse_image_path, unsparse_image_path]
output, exit_code = RunCommand(cmd)
if exit_code != 0:
print("%s: %s" % (error_message, output))
return False
return True
raise BuildImageError("{}:\n{}".format(error_message, output))
def Append(target, file_to_append, error_message):
"""Appends file_to_append to target."""
"""Appends file_to_append to target.
Raises:
BuildImageError: On error.
"""
try:
with open(target, "a") as out_file, open(file_to_append, "r") as input_file:
for line in input_file:
out_file.write(line)
except IOError:
print(error_message)
return False
return True
raise BuildImageError(error_message)
def BuildVerifiedImage(data_image_path, verity_image_path,
verity_metadata_path, verity_fec_path,
padding_size, fec_supported):
if not Append(verity_image_path, verity_metadata_path,
"Could not append verity metadata!"):
return False
Append(
verity_image_path, verity_metadata_path,
"Could not append verity metadata!")
if fec_supported:
# build FEC for the entire partition, including metadata
if not BuildVerityFEC(data_image_path, verity_image_path,
verity_fec_path, padding_size):
return False
# Build FEC for the entire partition, including metadata.
BuildVerityFEC(
data_image_path, verity_image_path, verity_fec_path, padding_size)
Append(verity_image_path, verity_fec_path, "Could not append FEC!")
if not Append(verity_image_path, verity_fec_path, "Could not append FEC!"):
return False
if not Append2Simg(data_image_path, verity_image_path,
"Could not append verity data!"):
return False
return True
Append2Simg(
data_image_path, verity_image_path, "Could not append verity data!")
def UnsparseImage(sparse_image_path, replace=True):
@ -409,15 +412,15 @@ def UnsparseImage(sparse_image_path, replace=True):
if replace:
os.unlink(unsparse_image_path)
else:
return True, unsparse_image_path
return unsparse_image_path
inflate_command = ["simg2img", sparse_image_path, unsparse_image_path]
(inflate_output, exit_code) = RunCommand(inflate_command)
inflate_output, exit_code = RunCommand(inflate_command)
if exit_code != 0:
print("Error: '%s' failed with exit code %d:\n%s" % (
inflate_command, exit_code, inflate_output))
os.remove(unsparse_image_path)
return False, None
return True, unsparse_image_path
raise BuildImageError(
"Error: '{}' failed with exit code {}:\n{}".format(
inflate_command, exit_code, inflate_output))
return unsparse_image_path
def MakeVerityEnabledImage(out_file, fec_supported, prop_dict):
@ -427,8 +430,10 @@ def MakeVerityEnabledImage(out_file, fec_supported, prop_dict):
out_file: the location to write the verifiable image at
prop_dict: a dictionary of properties required for image creation and
verification
Returns:
True on success, False otherwise.
Raises:
AssertionError: On invalid partition sizes.
BuildImageError: On other errors.
"""
# get properties
image_size = int(prop_dict["image_size"])
@ -440,50 +445,44 @@ def MakeVerityEnabledImage(out_file, fec_supported, prop_dict):
signer_path = prop_dict["verity_signer_cmd"]
signer_args = OPTIONS.verity_signer_args
# make a tempdir
tempdir_name = common.MakeTempDir(suffix="_verity_images")
# get partial image paths
# Get partial image paths.
verity_image_path = os.path.join(tempdir_name, "verity.img")
verity_metadata_path = os.path.join(tempdir_name, "verity_metadata.img")
verity_fec_path = os.path.join(tempdir_name, "verity_fec.img")
# build the verity tree and get the root hash and salt
if not BuildVerityTree(out_file, verity_image_path, prop_dict):
return False
# Build the verity tree and get the root hash and salt.
BuildVerityTree(out_file, verity_image_path, prop_dict)
# build the metadata blocks
# Build the metadata blocks.
root_hash = prop_dict["verity_root_hash"]
salt = prop_dict["verity_salt"]
verity_disable = "verity_disable" in prop_dict
if not BuildVerityMetadata(image_size, verity_metadata_path, root_hash, salt,
block_dev, signer_path, signer_key, signer_args,
verity_disable):
return False
BuildVerityMetadata(
image_size, verity_metadata_path, root_hash, salt, block_dev, signer_path,
signer_key, signer_args, verity_disable)
# build the full verified image
# Build the full verified image.
partition_size = int(prop_dict["partition_size"])
verity_size = int(prop_dict["verity_size"])
padding_size = partition_size - image_size - verity_size
assert padding_size >= 0
if not BuildVerifiedImage(out_file,
verity_image_path,
verity_metadata_path,
verity_fec_path,
padding_size,
fec_supported):
return False
return True
BuildVerifiedImage(
out_file, verity_image_path, verity_metadata_path, verity_fec_path,
padding_size, fec_supported)
def ConvertBlockMapToBaseFs(block_map_file):
base_fs_file = common.MakeTempFile(prefix="script_gen_", suffix=".base_fs")
convert_command = ["blk_alloc_to_base_fs", block_map_file, base_fs_file]
(_, exit_code) = RunCommand(convert_command)
return base_fs_file if exit_code == 0 else None
output, exit_code = RunCommand(convert_command)
if exit_code != 0:
raise BuildImageError(
"Failed to call blk_alloc_to_base_fs:\n{}".format(output))
return base_fs_file
def SetUpInDirAndFsConfig(origin_in, prop_dict):
@ -547,11 +546,9 @@ def CheckHeadroom(ext4fs_output, prop_dict):
ext4fs_output: The output string from mke2fs command.
prop_dict: The property dict.
Returns:
The check result.
Raises:
AssertionError: On invalid input.
BuildImageError: On check failure.
"""
assert ext4fs_output is not None
assert prop_dict.get('fs_type', '').startswith('ext4')
@ -569,12 +566,11 @@ def CheckHeadroom(ext4fs_output, prop_dict):
adjusted_blocks = total_blocks - headroom_blocks
if used_blocks > adjusted_blocks:
mount_point = prop_dict["mount_point"]
print("Error: Not enough room on %s (total: %d blocks, used: %d blocks, "
"headroom: %d blocks, available: %d blocks)" % (
mount_point, total_blocks, used_blocks, headroom_blocks,
adjusted_blocks))
return False
return True
raise BuildImageError(
"Error: Not enough room on {} (total: {} blocks, used: {} blocks, "
"headroom: {} blocks, available: {} blocks)".format(
mount_point, total_blocks, used_blocks, headroom_blocks,
adjusted_blocks))
def BuildImage(in_dir, prop_dict, out_file, target_out=None):
@ -590,8 +586,8 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
under system/core/libcutils) reads device specific FS config files from
there.
Returns:
True iff the image is built successfully.
Raises:
BuildImageError: On build image failures.
"""
in_dir, fs_config = SetUpInDirAndFsConfig(in_dir, prop_dict)
@ -620,10 +616,8 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
if (prop_dict.get("use_dynamic_partition_size") == "true" and
"partition_size" not in prop_dict):
# if partition_size is not defined, use output of `du' + reserved_size
success, size = GetDiskUsage(in_dir)
if not success:
return False
# If partition_size is not defined, use output of `du' + reserved_size.
size = GetDiskUsage(in_dir)
if OPTIONS.verbose:
print("The tree size of %s is %d MB." % (in_dir, size // BYTES_IN_MB))
size += int(prop_dict.get("partition_reserved_size", 0))
@ -647,8 +641,6 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
partition_size = int(prop_dict.get("partition_size"))
image_size, verity_size = AdjustPartitionSizeForVerity(
partition_size, verity_fec_supported)
if not image_size:
return False
prop_dict["image_size"] = str(image_size)
prop_dict["verity_size"] = str(verity_size)
@ -656,11 +648,8 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
if avb_footer_type:
partition_size = prop_dict["partition_size"]
# avb_add_hash_footer_args or avb_add_hashtree_footer_args.
max_image_size = AVBCalcMaxImageSize(avbtool, avb_footer_type,
partition_size, avb_signing_args)
if max_image_size <= 0:
print("AVBCalcMaxImageSize is <= 0: %d" % max_image_size)
return False
max_image_size = AVBCalcMaxImageSize(
avbtool, avb_footer_type, partition_size, avb_signing_args)
prop_dict["image_size"] = str(max_image_size)
if fs_type.startswith("ext"):
@ -683,8 +672,6 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
build_command.extend(["-B", prop_dict["block_list"]])
if "base_fs_file" in prop_dict:
base_fs_file = ConvertBlockMapToBaseFs(prop_dict["base_fs_file"])
if base_fs_file is None:
return False
build_command.extend(["-d", base_fs_file])
build_command.extend(["-L", prop_dict["mount_point"]])
if "extfs_inode_count" in prop_dict:
@ -742,16 +729,17 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
build_command.extend(["-T", str(prop_dict["timestamp"])])
build_command.extend(["-L", prop_dict["mount_point"]])
else:
print("Error: unknown filesystem type '%s'" % (fs_type))
return False
raise BuildImageError(
"Error: unknown filesystem type: {}".format(fs_type))
(mkfs_output, exit_code) = RunCommand(build_command)
mkfs_output, exit_code = RunCommand(build_command)
if exit_code != 0:
print("Error: '%s' failed with exit code %d:\n%s" % (
build_command, exit_code, mkfs_output))
success, du = GetDiskUsage(in_dir)
du_str = ("%d bytes (%d MB)" % (du, du // BYTES_IN_MB)
) if success else "unknown"
try:
du = GetDiskUsage(in_dir)
du_str = "{} bytes ({} MB)".format(du, du // BYTES_IN_MB)
except BuildImageError as e:
print(e, file=sys.stderr)
du_str = "unknown"
print(
"Out of space? The tree size of {} is {}, with reserved space of {} "
"bytes ({} MB).".format(
@ -765,28 +753,29 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
int(prop_dict["image_size"]) // BYTES_IN_MB,
int(prop_dict["partition_size"]),
int(prop_dict["partition_size"]) // BYTES_IN_MB))
return False
raise BuildImageError(
"Error: '{}' failed with exit code {}:\n{}".format(
build_command, exit_code, mkfs_output))
# Check if there's enough headroom space available for ext4 image.
if "partition_headroom" in prop_dict and fs_type.startswith("ext4"):
if not CheckHeadroom(mkfs_output, prop_dict):
return False
CheckHeadroom(mkfs_output, prop_dict)
if not fs_spans_partition:
mount_point = prop_dict.get("mount_point")
image_size = int(prop_dict["image_size"])
sparse_image_size = GetSimgSize(out_file)
if sparse_image_size > image_size:
print("Error: %s image size of %d is larger than partition size of "
"%d" % (mount_point, sparse_image_size, image_size))
return False
raise BuildImageError(
"Error: {} image size of {} is larger than partition size of "
"{}".format(mount_point, sparse_image_size, image_size))
if verity_supported and is_verity_partition:
ZeroPadSimg(out_file, image_size - sparse_image_size)
# Create the verified image if this is to be verified.
if verity_supported and is_verity_partition:
if not MakeVerityEnabledImage(out_file, verity_fec_supported, prop_dict):
return False
MakeVerityEnabledImage(out_file, verity_fec_supported, prop_dict)
# Add AVB HASH or HASHTREE footer (metadata).
if avb_footer_type:
@ -796,30 +785,25 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None):
key_path = prop_dict.get("avb_key_path")
algorithm = prop_dict.get("avb_algorithm")
salt = prop_dict.get("avb_salt")
if not AVBAddFooter(out_file, avbtool, avb_footer_type,
partition_size, partition_name, key_path,
algorithm, salt, avb_signing_args):
return False
AVBAddFooter(
out_file, avbtool, avb_footer_type, partition_size, partition_name,
key_path, algorithm, salt, avb_signing_args)
if run_e2fsck and prop_dict.get("skip_fsck") != "true":
success, unsparse_image = UnsparseImage(out_file, replace=False)
if not success:
return False
unsparse_image = UnsparseImage(out_file, replace=False)
# Run e2fsck on the inflated image file
e2fsck_command = ["e2fsck", "-f", "-n", unsparse_image]
# TODO(b/112062612): work around e2fsck failure with SANITIZE_HOST=address
env4e2fsck = {"ASAN_OPTIONS": "detect_odr_violation=0"}
(e2fsck_output, exit_code) = RunCommand(e2fsck_command, env=env4e2fsck)
e2fsck_output, exit_code = RunCommand(e2fsck_command, env=env4e2fsck)
os.remove(unsparse_image)
if exit_code != 0:
print("Error: '%s' failed with exit code %d:\n%s" % (
e2fsck_command, exit_code, e2fsck_output))
return False
return True
raise BuildImageError(
"Error: '{}' failed with exit code {}:\n{}".format(
e2fsck_command, exit_code, e2fsck_output))
def ImagePropFromGlobalDict(glob_dict, mount_point):
@ -1110,10 +1094,12 @@ def main(argv):
image_properties = ImagePropFromGlobalDict(glob_dict, mount_point)
if not BuildImage(in_dir, image_properties, out_file, target_out):
print("error: failed to build %s from %s" % (out_file, in_dir),
try:
BuildImage(in_dir, image_properties, out_file, target_out)
except:
print("Error: Failed to build {} from {}".format(out_file, in_dir),
file=sys.stderr)
sys.exit(1)
raise
if prop_file_out:
glob_dict_out = GlobalDictFromImageProp(image_properties, mount_point)

View file

@ -22,8 +22,8 @@ import unittest
import common
from build_image import (
AVBCalcMinPartitionSize, BLOCK_SIZE,
CheckHeadroom, RunCommand, SetUpInDirAndFsConfig)
AVBCalcMinPartitionSize, BLOCK_SIZE, BuildImageError, CheckHeadroom,
RunCommand, SetUpInDirAndFsConfig)
class BuildImageTest(unittest.TestCase):
@ -49,7 +49,7 @@ class BuildImageTest(unittest.TestCase):
'partition_headroom' : '4096000',
'mount_point' : 'system',
}
self.assertTrue(CheckHeadroom(self.EXT4FS_OUTPUT, prop_dict))
CheckHeadroom(self.EXT4FS_OUTPUT, prop_dict)
def test_CheckHeadroom_InsufficientHeadroom(self):
# Required headroom: 1001 blocks.
@ -58,7 +58,8 @@ class BuildImageTest(unittest.TestCase):
'partition_headroom' : '4100096',
'mount_point' : 'system',
}
self.assertFalse(CheckHeadroom(self.EXT4FS_OUTPUT, prop_dict))
self.assertRaises(
BuildImageError, CheckHeadroom, self.EXT4FS_OUTPUT, prop_dict)
def test_CheckHeadroom_WrongFsType(self):
prop_dict = {
@ -98,14 +99,14 @@ class BuildImageTest(unittest.TestCase):
'partition_headroom' : '40960',
'mount_point' : 'system',
}
self.assertTrue(CheckHeadroom(ext4fs_output, prop_dict))
CheckHeadroom(ext4fs_output, prop_dict)
prop_dict = {
'fs_type' : 'ext4',
'partition_headroom' : '413696',
'mount_point' : 'system',
}
self.assertFalse(CheckHeadroom(ext4fs_output, prop_dict))
self.assertRaises(BuildImageError, CheckHeadroom, ext4fs_output, prop_dict)
def test_SetUpInDirAndFsConfig_SystemRootImageTrue_NonSystem(self):
prop_dict = {

View file

@ -139,8 +139,7 @@ class ValidateTargetFilesTest(unittest.TestCase):
'verity_signer_cmd' : 'verity_signer',
'verity_size' : str(verity_size),
}
self.assertTrue(
build_image.MakeVerityEnabledImage(output_file, verity_fec, prop_dict))
build_image.MakeVerityEnabledImage(output_file, verity_fec, prop_dict)
def test_ValidateVerifiedBootImages_systemImage(self):
input_tmp = common.MakeTempDir()