[aarch64] Add ARM support to helper.py (#8332)

This is probably a lot of what is needed for CFL support (though there's probably a lot of other stuff left).
Related: #8164

infra/helper.py

@@ -69,6 +69,7 @@
 WORKDIR_REGEX = re.compile(r'\s*WORKDIR\s*([^\s]+)')
 
 LANGUAGES_WITH_BUILDER_IMAGES = {'go', 'jvm', 'python', 'rust', 'swift'}
+ARM_BUILDER_NAME = 'oss-fuzz-buildx-builder'
 
 if sys.version_info[0] >= 3:
   raw_input = input  # pylint: disable=invalid-name
@@ -240,6 +241,7 @@ def get_parser():  # pylint: disable=too-many-statements
   build_image_parser.add_argument('--pull',
                                   action='store_true',
                                   help='Pull latest base image.')
+  _add_architecture_args(build_image_parser)
   build_image_parser.add_argument('--cache',
                                   action='store_true',
                                   default=False,
@@ -387,9 +389,10 @@ def check_project_exists(project):
   return False
 
 
-def _check_fuzzer_exists(project, fuzzer_name):
+def _check_fuzzer_exists(project, fuzzer_name, architecture='x86_64'):
   """Checks if a fuzzer exists."""
-  command = ['docker', 'run', '--rm']
+  platform = 'linux/arm64' if architecture == 'aarch64' else 'linux/amd64'
+  command = ['docker', 'run', '--rm', '--platform', platform]
   command.extend(['-v', '%s:/out' % project.out])
   command.append(BASE_RUNNER_IMAGE)
 
@@ -466,7 +469,7 @@ def _add_environment_args(parser):
                       help="set environment variable e.g. VAR=value")
 
 
-def build_image_impl(project, cache=True, pull=False):
+def build_image_impl(project, cache=True, pull=False, architecture='x86_64'):
   """Builds image."""
   image_name = project.name
 
@@ -486,14 +489,27 @@ def build_image_impl(project, cache=True, pull=False):
     return False
 
   build_args = []
+  image_name = 'gcr.io/%s/%s' % (image_project, image_name)
+  if architecture == 'aarch64':
+    build_args += [
+        'buildx',
+        'build',
+        '--platform',
+        'linux/arm64',
+        '--progress',
+        'plain',
+        '--load',
+    ]
   if not cache:
     build_args.append('--no-cache')
 
-  build_args += [
-      '-t',
-      'gcr.io/%s/%s' % (image_project, image_name), '--file', dockerfile_path
-  ]
+  build_args += ['-t', image_name, '--file', dockerfile_path]
   build_args.append(docker_build_dir)
+
+  if architecture == 'aarch64':
+    command = ['docker'] + build_args
+    subprocess.check_call(command)
+    return True
   return docker_build(build_args)
 
 
@@ -526,10 +542,18 @@ def _workdir_from_dockerfile(project):
   return workdir_from_lines(lines, default=os.path.join('/src', project.name))
 
 
-def docker_run(run_args, print_output=True):
-  """Calls `docker run`."""
-  command = ['docker', 'run', '--rm', '--privileged']
+def prepare_aarch64_emulation():
+  """Run some necessary commands to use buildx to build AArch64 targets using
+  QEMU emulation on an x86_64 host."""
+  subprocess.check_call(
+      ['docker', 'buildx', 'create', '--name', ARM_BUILDER_NAME])
+  subprocess.check_call(['docker', 'buildx', 'use', ARM_BUILDER_NAME])
+
 
+def docker_run(run_args, print_output=True, architecture='x86_64'):
+  """Calls `docker run`."""
+  platform = 'linux/arm64' if architecture == 'aarch64' else 'linux/amd64'
+  command = ['docker', 'run', '--rm', '--privileged', '--platform', platform]
   # Support environments with a TTY.
   if sys.stdin.isatty():
     command.append('-i')
@@ -598,7 +622,10 @@ def build_image(args):
     logging.info('Using cached base images...')
 
   # If build_image is called explicitly, don't use cache.
-  if build_image_impl(args.project, cache=args.cache, pull=pull):
+  if build_image_impl(args.project,
+                      cache=args.cache,
+                      pull=pull,
+                      architecture=args.architecture):
     return True
 
   return False
@@ -614,7 +641,7 @@ def build_fuzzers_impl(  # pylint: disable=too-many-arguments,too-many-locals,to
     source_path,
     mount_path=None):
   """Builds fuzzers."""
-  if not build_image_impl(project):
+  if not build_image_impl(project, architecture=architecture):
     return False
 
   if clean:
@@ -625,13 +652,15 @@ def build_fuzzers_impl(  # pylint: disable=too-many-arguments,too-many-locals,to
         '-v',
         '%s:/out' % project.out, '-t',
         'gcr.io/oss-fuzz/%s' % project.name, '/bin/bash', '-c', 'rm -rf /out/*'
-    ])
+    ],
+               architecture=architecture)
 
     docker_run([
         '-v',
         '%s:/work' % project.work, '-t',
         'gcr.io/oss-fuzz/%s' % project.name, '/bin/bash', '-c', 'rm -rf /work/*'
-    ])
+    ],
+               architecture=architecture)
 
   else:
     logging.info('Keeping existing build artifacts as-is (if any).')
@@ -673,7 +702,7 @@ def build_fuzzers_impl(  # pylint: disable=too-many-arguments,too-many-locals,to
       'gcr.io/oss-fuzz/%s' % project.name
   ]
 
-  result = docker_run(command)
+  result = docker_run(command, architecture=architecture)
   if not result:
     logging.error('Building fuzzers failed.')
     return False
@@ -705,8 +734,8 @@ def check_build(args):
   if not check_project_exists(args.project):
     return False
 
-  if (args.fuzzer_name and
-      not _check_fuzzer_exists(args.project, args.fuzzer_name)):
+  if (args.fuzzer_name and not _check_fuzzer_exists(
+      args.project, args.fuzzer_name, args.architecture)):
     return False
 
   env = [
@@ -728,7 +757,7 @@ def check_build(args):
   else:
     run_args.append('test_all.py')
 
-  result = docker_run(run_args)
+  result = docker_run(run_args, architecture=args.architecture)
   if result:
     logging.info('Check build passed.')
   else:
@@ -940,7 +969,7 @@ def run_fuzzer(args):
       args.fuzzer_name,
   ] + args.fuzzer_args)
 
-  return docker_run(run_args)
+  return docker_run(run_args, architecture=args.architecture)
 
 
 def reproduce(args):
@@ -1128,7 +1157,7 @@ def shell(args):
       'gcr.io/%s/%s' % (image_project, args.project.name), '/bin/bash'
   ])
 
-  docker_run(run_args)
+  docker_run(run_args, architecture=args.architecture)
   return True