Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4014a9da authored by David Zeuthen's avatar David Zeuthen
Browse files

Make room for AVB hashtree and metadata. 

While the system.img images currently built with AVB support verify
correctly, mounting the filesystem content fails. This is because
'avbtool add_hashtree_footer' used to claim some of the unused /
DONT_CARE space for stashing the verity tables and this resulting in the
mapped device ending up being smaller causing the mount failure.

Fix this by leaving enough room for AVB hashtree and metadata before
building the image. This is achieved by moving the AVB hashtree support
into build_image.py and using a just added '--calc_max_image_size'
option to 'avbtool add_hashtree_footer' to figure out how much space to
leave out.

This depends on https://android-review.googlesource.com/#/c/281821/

Bug: 31264226
Test: Mounting dm-verity set up from system.img now works.

Merged-In: I4c5de1004c1059f8c582e76b3b8517d427aa1a87

Change-Id: I945a5f1f6782791736cd319f216cfa6b448fb04d
parent 0a5b59e7

core/Makefile

+4 −7
Original line number Diff line number Diff line
@@ -873,6 +873,10 @@ $(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot_ 
$(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot_subkey=$(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_VBOOT_SIGNING_SUBKEY)" >> $(1))

$(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "futility=$(FUTILITY)" >> $(1))

$(if $(PRODUCTS.$(INTERNAL_PRODUCT).PRODUCT_SUPPORTS_VBOOT),$(hide) echo "vboot_signer_cmd=$(VBOOT_SIGNER)" >> $(1))

$(if $(BOARD_AVB_ENABLE),$(hide) echo "avb_signing_args=$(INTERNAL_AVB_SIGNING_ARGS)" >> $(1))

$(if $(BOARD_AVB_ENABLE),$(hide) echo "avb_avbtool=$(AVBTOOL)" >> $(1))

$(if $(BOARD_AVB_ENABLE),$(hide) echo "system_avb_enable=$(BOARD_AVB_ENABLE)" >> $(1))

$(if $(BOARD_AVB_ENABLE),$(hide) echo "system_avb_add_hashtree_footer_args=$(BOARD_AVB_SYSTEM_ADD_HASHTREE_FOOTER_ARGS)" >> $(1))

$(if $(filter true,$(BOARD_USES_RECOVERY_AS_BOOT)),\

    $(hide) echo "recovery_as_boot=true" >> $(1))

$(if $(filter true,$(BOARD_BUILD_SYSTEM_ROOT_IMAGE)),\
@@ -1180,13 +1184,6 @@ define build-systemimage-target 
           fi; \

           mkdir -p $(DIST_DIR); cp $(INSTALLED_FILES_FILE) $(DIST_DIR)/installed-files-rescued.txt; \

           exit 1 )

  $(if $(BOARD_AVB_ENABLE), \

    $(hide) $(AVBTOOL) add_hashtree_footer \

      --image $(1) \

      --partition_size $(BOARD_SYSTEMIMAGE_PARTITION_SIZE) \

      --partition_name system \

      $(INTERNAL_AVB_SIGNING_ARGS) \

      $(BOARD_AVB_SYSTEM_ADD_HASHTREE_FOOTER_ARGS))

endef



$(BUILT_SYSTEMIMAGE): $(FULL_SYSTEMIMAGE_DEPS) $(INSTALLED_FILES_FILE) $(BUILD_IMAGE_SRCS)

tools/releasetools/add_img_to_target_files.py

+0 −17
Original line number Diff line number Diff line
@@ -96,23 +96,6 @@ def AddSystem(output_zip, prefix="IMAGES/", recovery_img=None, boot_img=None): 
  imgname = BuildSystem(OPTIONS.input_tmp, OPTIONS.info_dict,

                        block_list=block_list)



  # AVB: if enabled, calculate and add dm-verity integrity hashes and

  # metadata to system.img.

  if OPTIONS.info_dict.get("board_avb_enable", None) == "true":

    avbtool = os.getenv('AVBTOOL') or "avbtool"

    part_size = OPTIONS.info_dict.get("system_size", None)

    cmd = [avbtool, "add_hashtree_footer", "--image", imgname,

           "--partition_size", str(part_size), "--partition_name", "system"]

    common.AppendAVBSigningArgs(cmd)

    args = OPTIONS.info_dict.get("board_avb_system_add_hashtree_footer_args",

                                 None)

    if args and args.strip():

      cmd.extend(shlex.split(args))

    p = common.Run(cmd, stdout=subprocess.PIPE)

    p.communicate()

    assert p.returncode == 0, "avbtool add_hashtree_footer of %s failed" % (

      os.path.basename(OPTIONS.input_tmp))



  common.ZipWrite(output_zip, imgname, prefix + "system.img")

  common.ZipWrite(output_zip, block_list, prefix + "system.map")

  return imgname

tools/releasetools/build_image.py

+79 −2
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ import subprocess 
import sys

import commands

import common

import shlex

import shutil

import sparse_img

import tempfile
@@ -102,6 +103,51 @@ def ZeroPadSimg(image_file, pad_size): 
  simg = sparse_img.SparseImage(image_file, mode="r+b", build_map=False)

  simg.AppendFillChunk(0, blocks)



def AVBCalcMaxImageSize(avbtool, partition_size, additional_args):

  """Calculates max image size for a given partition size.



  Args:

    avbtool: String with path to avbtool.

    partition_size: The size of the partition in question.

    additional_args: Additional arguments to pass to 'avbtool

      add_hashtree_image'.

  Returns:

    The maximum image size or 0 if an error occurred.

  """

  cmdline = "%s add_hashtree_footer " % avbtool

  cmdline += "--partition_size %d " % partition_size

  cmdline += "--calc_max_image_size "

  cmdline += additional_args

  (output, exit_code) = RunCommand(shlex.split(cmdline))

  if exit_code != 0:

    return 0

  else:

    return int(output)



def AVBAddHashtree(image_path, avbtool, partition_size, partition_name,

                   signing_args, additional_args):

  """Adds dm-verity hashtree and AVB metadata to an image.



  Args:

    image_path: Path to image to modify.

    avbtool: String with path to avbtool.

    partition_size: The size of the partition in question.

    partition_name: The name of the partition - will be embedded in metadata.

    signing_args: Arguments for signing the image.

    additional_args: Additional arguments to pass to 'avbtool

      add_hashtree_image'.

  Returns:

    True if the operation succeeded.

  """

  cmdline = "%s add_hashtree_footer " % avbtool

  cmdline += "--partition_size %d " % partition_size

  cmdline += "--partition_name %s " % partition_name

  cmdline += "--image %s " % image_path

  cmdline += signing_args + " "

  cmdline += additional_args

  (_, exit_code) = RunCommand(shlex.split(cmdline))

  return exit_code == 0



def AdjustPartitionSizeForVerity(partition_size, fec_supported):

  """Modifies the provided partition size to account for the verity metadata.
@@ -375,6 +421,18 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None): 
    prop_dict["original_partition_size"] = str(partition_size)

    prop_dict["verity_size"] = str(verity_size)



  # Adjust partition size for AVB.

  if prop_dict.get("avb_enable") == "true":

    avbtool = prop_dict.get("avb_avbtool")

    partition_size = int(prop_dict.get("partition_size"))

    additional_args = prop_dict["avb_add_hashtree_footer_args"]

    max_image_size = AVBCalcMaxImageSize(avbtool, partition_size,

                                         additional_args)

    if max_image_size == 0:

      return False

    prop_dict["partition_size"] = str(max_image_size)

    prop_dict["original_partition_size"] = str(partition_size)



  if fs_type.startswith("ext"):

    build_command = ["mkuserimg.sh"]

    if "extfs_sparse_flag" in prop_dict:
@@ -497,6 +555,17 @@ def BuildImage(in_dir, prop_dict, out_file, target_out=None): 
    if not MakeVerityEnabledImage(out_file, verity_fec_supported, prop_dict):

      return False



  # Add AVB hashtree and metadata.

  if "avb_enable" in prop_dict:

    avbtool = prop_dict.get("avb_avbtool")

    original_partition_size = int(prop_dict.get("original_partition_size"))

    partition_name = prop_dict["partition_name"]

    signing_args = prop_dict["avb_signing_args"]

    additional_args = prop_dict["avb_add_hashtree_footer_args"]

    if not AVBAddHashtree(out_file, avbtool, original_partition_size,

                          partition_name, signing_args, additional_args):

      return False



  if run_fsck and prop_dict.get("skip_fsck") != "true":

    success, unsparse_image = UnsparseImage(out_file, replace=False)

    if not success:
@@ -537,7 +606,9 @@ def ImagePropFromGlobalDict(glob_dict, mount_point): 
      "verity",

      "verity_key",

      "verity_signer_cmd",

      "verity_fec"

      "verity_fec",

      "avb_signing_args",

      "avb_avbtool"

      )

  for p in common_props:

    copy_prop(p, p)
@@ -559,6 +630,9 @@ def ImagePropFromGlobalDict(glob_dict, mount_point): 
    copy_prop("system_squashfs_compressor_opt", "squashfs_compressor_opt")

    copy_prop("system_squashfs_disable_4k_align", "squashfs_disable_4k_align")

    copy_prop("system_base_fs_file", "base_fs_file")

    copy_prop("system_avb_enable", "avb_enable")

    copy_prop("system_avb_add_hashtree_footer_args",

              "avb_add_hashtree_footer_args")

  elif mount_point == "data":

    # Copy the generic fs type first, override with specific one if available.

    copy_prop("fs_type", "fs_type")
@@ -577,12 +651,15 @@ def ImagePropFromGlobalDict(glob_dict, mount_point): 
    copy_prop("vendor_squashfs_compressor_opt", "squashfs_compressor_opt")

    copy_prop("vendor_squashfs_disable_4k_align", "squashfs_disable_4k_align")

    copy_prop("vendor_base_fs_file", "base_fs_file")

    copy_prop("vendor_avb_enable", "avb_enable")

    copy_prop("vendor_avb_add_hashtree_footer_args",

              "avb_add_hashtree_footer_args")

  elif mount_point == "oem":

    copy_prop("fs_type", "fs_type")

    copy_prop("oem_size", "partition_size")

    copy_prop("oem_journal_size", "journal_size")

    copy_prop("has_ext4_reserved_blocks", "has_ext4_reserved_blocks")



  d["partition_name"] = mount_point

  return d