def grandchild():
"""Setup everything inside the process that finally exec()s the tool."""
try:
# We know that this process has PID 2 in the inner namespace,
# but we actually need to know its PID in the outer namespace
# such that parent can put us into the correct cgroups. According to
# http://man7.org/linux/man-pages/man7/pid_namespaces.7.html,
# there are two ways to achieve this: sending a message with the PID
# via a socket (but Python 2 lacks a convenient API for sendmsg),
# and reading /proc/self in the outer procfs instance
# (that's what we do).
my_outer_pid = container.get_my_pid_from_procfs()
container.mount_proc(self._container_system_config)
container.drop_capabilities()
container.reset_signal_handling()
child_setup_fn() # Do some other setup the caller wants.
# Signal readiness to parent by sending our PID
# and wait until parent is also ready
os.write(to_parent, str(my_outer_pid).encode())
received = os.read(from_parent, 1)
assert received == MARKER_PARENT_COMPLETED, received
finally:
# close remaining ends of pipe
os.close(from_parent)
os.close(to_parent)
def grandchild():
"""Setup everything inside the process that finally exec()s the tool."""
try:
# We know that this process has PID 2 in the inner namespace,
# but we actually need to know its PID in the outer namespace
# such that parent can put us into the correct cgroups.
# According to http://man7.org/linux/man-pages/man7/pid_namespaces.7.html,
# there are two ways to achieve this: sending a message with the PID
# via a socket (but Python < 3.3 lacks a convenient API for sendmsg),
# and reading /proc/self in the outer procfs instance (that's what we do).
my_outer_pid = container.get_my_pid_from_procfs()
container.mount_proc()
container.drop_capabilities()
container.reset_signal_handling()
child_setup_fn() # Do some other setup the caller wants.
# Signal readiness to parent by sending our PID and wait until parent is also ready
os.write(to_parent, str(my_outer_pid).encode())
received = os.read(from_parent, 1)
assert received == b"\0", received
finally:
# close remaining ends of pipe
os.close(from_parent)
os.close(to_parent)
def child():
"""Setup everything inside the container,
start the tool, and wait for result."""
try:
logging.debug(
"Child: child process of RunExecutor with PID %d started",
container.get_my_pid_from_procfs(),
)
# Put all received signals on hold until we handle them later.
container.block_all_signals()
# We want to avoid leaking file descriptors to the executed child.
# It is also nice if the child has only the minimal necessary file
# descriptors, to avoid keeping other pipes and files open, e.g.,
# those that the parent uses to communicate with other containers
# (if containers are started in parallel).
# Thus we do not use the close_fds feature of subprocess.Popen,
# but do the same here manually. We keep the relevant ends of our pipes,
# and stdin/out/err of child and grandchild.
necessary_fds = {
sys.stdin,
sys.stdout,
sys.stderr,
to_parent,
from_parent,
stdin,
stdout,
stderr,
} - {None}
container.close_open_fds(keep_files=necessary_fds)
try:
if self._container_system_config:
# A standard hostname increases reproducibility.
socket.sethostname(container.CONTAINER_HOSTNAME)
if not self._allow_network:
container.activate_network_interface("lo")
# Wait until user mapping is finished,
# this is necessary for filesystem writes
received = os.read(from_parent,
len(MARKER_USER_MAPPING_COMPLETED))
assert received == MARKER_USER_MAPPING_COMPLETED, received
if root_dir is not None:
self._setup_root_filesystem(root_dir)
else:
self._setup_container_filesystem(
temp_dir,
output_dir if result_files_patterns else None,
memlimit,
memory_nodes,
)
# Marking this process as "non-dumpable" (no core dumps) also
# forbids several other ways how other processes can access and
# influence it:
# ptrace is forbidden and much of /proc/<child>/ is inaccessible.
# We set this to prevent the benchmarked tool from messing with this
# process or using it to escape from the container. More info:
# http://man7.org/linux/man-pages/man5/proc.5.html
# It needs to be done after MARKER_USER_MAPPING_COMPLETED.
libc.prctl(libc.PR_SET_DUMPABLE, libc.SUID_DUMP_DISABLE, 0,
0, 0)
except OSError as e:
logging.critical("Failed to configure container: %s", e)
return CHILD_OSERROR
try:
os.chdir(cwd)
except OSError as e:
logging.critical(
"Cannot change into working directory inside container: %s",
e)
return CHILD_OSERROR
container.setup_seccomp_filter()
try:
grandchild_proc = subprocess.Popen(
args,
stdin=stdin,
stdout=stdout,
stderr=stderr,
env=env,
close_fds=False,
preexec_fn=grandchild,
)
except (OSError, RuntimeError) as e:
logging.critical("Cannot start process: %s", e)
return CHILD_OSERROR
# keep capability for unmount if necessary later
necessary_capabilities = ([libc.CAP_SYS_ADMIN]
if result_files_patterns else [])
container.drop_capabilities(keep=necessary_capabilities)
# Close other fds that were still necessary above.
container.close_open_fds(keep_files={
sys.stdout, sys.stderr, to_parent, from_parent
})
# Set up signal handlers to forward signals to grandchild
# (because we are PID 1, there is a special signal handling otherwise).
# cf. dumb-init project: https://github.com/Yelp/dumb-init
# Also wait for grandchild and return its result.
grandchild_result = container.wait_for_child_and_forward_signals(
grandchild_proc.pid, args[0])
logging.debug(
"Child: process %s terminated with exit code %d.",
args[0],
grandchild_result[0],
)
if result_files_patterns:
# Remove the bind mount that _setup_container_filesystem added
# such that the parent can access the result files.
libc.umount(temp_dir.encode())
# Re-allow access to /proc/<child>/...,
# this is used by the parent for accessing output files
libc.prctl(libc.PR_SET_DUMPABLE, libc.SUID_DUMP_USER, 0, 0, 0)
os.write(to_parent, pickle.dumps(grandchild_result))
os.close(to_parent)
# Now the parent copies the output files, we need to wait until this is
# finished. If the child terminates, the container file system and its
# tmpfs go away.
assert os.read(from_parent,
1) == MARKER_PARENT_POST_RUN_COMPLETED
os.close(from_parent)
return 0
except OSError:
logging.exception("Error in child process of RunExecutor")
return CHILD_OSERROR
except BaseException:
# Need to catch everything because this method always needs to return an
# int (we are inside a C callback that requires returning int).
logging.exception("Error in child process of RunExecutor")
return CHILD_UNKNOWN_ERROR
def child():
"""Setup everything inside the container, start the tool, and wait for result."""
try:
logging.debug("Child: child process of RunExecutor with PID %d started",
container.get_my_pid_from_procfs())
# We want to avoid leaking file descriptors to the executed child.
# It is also nice if the child has only the minimal necessary file descriptors,
# to avoid keeping other pipes and files open, e.g., those that the parent
# uses to communicate with other containers (if containers are started in parallel).
# Thus we do not use the close_fds feature of subprocess.Popen,
# but do the same here manually.
# We keep the relevant ends of our pipes, and stdin/out/err of child and grandchild.
necessary_fds = {sys.stdin, sys.stdout, sys.stderr,
to_parent, from_parent, stdin, stdout, stderr} - {None}
container.close_open_fds(keep_files=necessary_fds)
try:
if not self._allow_network:
container.activate_network_interface("lo")
self._setup_container_filesystem(temp_dir)
except EnvironmentError as e:
logging.critical("Failed to configure container: %s", e)
return int(e.errno)
try:
os.chdir(cwd)
except EnvironmentError as e:
logging.critical(
"Cannot change into working directory inside container: %s", e)
return int(e.errno)
try:
grandchild_proc = subprocess.Popen(args,
stdin=stdin,
stdout=stdout, stderr=stderr,
env=env,
close_fds=False,
preexec_fn=grandchild)
except (EnvironmentError, RuntimeError) as e:
logging.critical("Cannot start process: %s", e)
try:
return int(e.errno)
except BaseException:
# subprocess.Popen in Python 2.7 throws OSError with errno=None
# if the preexec_fn fails.
return -2
container.drop_capabilities()
# Set up signal handlers to forward signals to grandchild
# (because we are PID 1, there is a special signal handling otherwise).
# cf. dumb-init project: https://github.com/Yelp/dumb-init
container.forward_all_signals(grandchild_proc.pid, args[0])
# Close other fds that were still necessary above.
container.close_open_fds(keep_files={sys.stdout, sys.stderr, to_parent})
# wait for grandchild and return its result
grandchild_result = self._wait_for_process(grandchild_proc.pid, args[0])
logging.debug("Child: process %s terminated with exit code %d.",
args[0], grandchild_result[0])
os.write(to_parent, pickle.dumps(grandchild_result))
os.close(to_parent)
return 0
except EnvironmentError as e:
logging.exception("Error in child process of RunExecutor")
return int(e.errno)
except:
# Need to catch everything because this method always needs to return a int
# (we are inside a C callback that requires returning int).
logging.exception("Error in child process of RunExecutor")
return -1
def child():
"""Setup everything inside the container, start the tool, and wait for result."""
try:
logging.debug(
"Child: child process of RunExecutor with PID %d started",
container.get_my_pid_from_procfs())
# Put all received signals on hold until we handle them later.
container.block_all_signals()
# We want to avoid leaking file descriptors to the executed child.
# It is also nice if the child has only the minimal necessary file descriptors,
# to avoid keeping other pipes and files open, e.g., those that the parent
# uses to communicate with other containers (if containers are started in parallel).
# Thus we do not use the close_fds feature of subprocess.Popen,
# but do the same here manually.
# We keep the relevant ends of our pipes, and stdin/out/err of child and grandchild.
necessary_fds = {
sys.stdin, sys.stdout, sys.stderr, to_parent, from_parent,
stdin, stdout, stderr
} - {None}
container.close_open_fds(keep_files=necessary_fds)
try:
if not self._allow_network:
container.activate_network_interface("lo")
if root_dir is not None:
self._setup_root_filesystem(root_dir)
else:
self._setup_container_filesystem(temp_dir)
except EnvironmentError as e:
logging.critical("Failed to configure container: %s", e)
return CHILD_OSERROR
try:
os.chdir(cwd)
except EnvironmentError as e:
logging.critical(
"Cannot change into working directory inside container: %s",
e)
return CHILD_OSERROR
try:
grandchild_proc = subprocess.Popen(args,
stdin=stdin,
stdout=stdout,
stderr=stderr,
env=env,
close_fds=False,
preexec_fn=grandchild)
except (EnvironmentError, RuntimeError) as e:
logging.critical("Cannot start process: %s", e)
return CHILD_OSERROR
container.drop_capabilities()
# Close other fds that were still necessary above.
container.close_open_fds(
keep_files={sys.stdout, sys.stderr, to_parent})
# Set up signal handlers to forward signals to grandchild
# (because we are PID 1, there is a special signal handling otherwise).
# cf. dumb-init project: https://github.com/Yelp/dumb-init
# Also wait for grandchild and return its result.
if _HAS_SIGWAIT:
grandchild_result = container.wait_for_child_and_forward_all_signals(
grandchild_proc.pid, args[0])
else:
container.forward_all_signals_async(
grandchild_proc.pid, args[0])
grandchild_result = self._wait_for_process(
grandchild_proc.pid, args[0])
logging.debug(
"Child: process %s terminated with exit code %d.", args[0],
grandchild_result[0])
os.write(to_parent, pickle.dumps(grandchild_result))
os.close(to_parent)
return 0
except EnvironmentError as e:
logging.exception("Error in child process of RunExecutor")
return CHILD_OSERROR
except:
# Need to catch everything because this method always needs to return a int
# (we are inside a C callback that requires returning int).
logging.exception("Error in child process of RunExecutor")
return CHILD_UNKNOWN_ERROR
def child():
"""Setup everything inside the container, start the tool, and wait for result."""
try:
logging.debug("Child: child process of RunExecutor with PID %d started",
container.get_my_pid_from_procfs())
# Put all received signals on hold until we handle them later.
container.block_all_signals()
# We want to avoid leaking file descriptors to the executed child.
# It is also nice if the child has only the minimal necessary file descriptors,
# to avoid keeping other pipes and files open, e.g., those that the parent
# uses to communicate with other containers (if containers are started in parallel).
# Thus we do not use the close_fds feature of subprocess.Popen,
# but do the same here manually.
# We keep the relevant ends of our pipes, and stdin/out/err of child and grandchild.
necessary_fds = {sys.stdin, sys.stdout, sys.stderr,
to_parent, from_parent, stdin, stdout, stderr} - {None}
container.close_open_fds(keep_files=necessary_fds)
try:
if self._container_system_config:
# A standard hostname increases reproducibility.
libc.sethostname(container.CONTAINER_HOSTNAME)
if not self._allow_network:
container.activate_network_interface("lo")
# Wait until user mapping is finished, this is necessary for filesystem writes
received = os.read(from_parent, len(MARKER_USER_MAPPING_COMPLETED))
assert received == MARKER_USER_MAPPING_COMPLETED, received
if root_dir is not None:
self._setup_root_filesystem(root_dir)
else:
self._setup_container_filesystem(
temp_dir,
output_dir if result_files_patterns else None,
memlimit,
memory_nodes)
except EnvironmentError as e:
logging.critical("Failed to configure container: %s", e)
return CHILD_OSERROR
try:
os.chdir(cwd)
except EnvironmentError as e:
logging.critical(
"Cannot change into working directory inside container: %s", e)
return CHILD_OSERROR
try:
grandchild_proc = subprocess.Popen(args,
stdin=stdin,
stdout=stdout, stderr=stderr,
env=env,
close_fds=False,
preexec_fn=grandchild)
except (EnvironmentError, RuntimeError) as e:
logging.critical("Cannot start process: %s", e)
return CHILD_OSERROR
# keep capability for unmount if necessary later
necessary_capabilities = [libc.CAP_SYS_ADMIN] if result_files_patterns else []
container.drop_capabilities(keep=necessary_capabilities)
# Close other fds that were still necessary above.
container.close_open_fds(keep_files={sys.stdout, sys.stderr, to_parent, from_parent})
# Set up signal handlers to forward signals to grandchild
# (because we are PID 1, there is a special signal handling otherwise).
# cf. dumb-init project: https://github.com/Yelp/dumb-init
# Also wait for grandchild and return its result.
if _HAS_SIGWAIT:
grandchild_result = container.wait_for_child_and_forward_all_signals(
grandchild_proc.pid, args[0])
else:
container.forward_all_signals_async(grandchild_proc.pid, args[0])
grandchild_result = self._wait_for_process(grandchild_proc.pid, args[0])
logging.debug("Child: process %s terminated with exit code %d.",
args[0], grandchild_result[0])
if result_files_patterns:
# Remove the bind mount that _setup_container_filesystem added
# such that the parent can access the result files.
libc.umount(temp_dir.encode())
os.write(to_parent, pickle.dumps(grandchild_result))
os.close(to_parent)
# Now the parent copies the output files, we need to wait until this is finished.
# If the child terminates, the container file system and its tmpfs go away.
os.read(from_parent, 1)
os.close(from_parent)
return 0
except EnvironmentError as e:
logging.exception("Error in child process of RunExecutor")
return CHILD_OSERROR
except:
# Need to catch everything because this method always needs to return a int
# (we are inside a C callback that requires returning int).
logging.exception("Error in child process of RunExecutor")
return CHILD_UNKNOWN_ERROR
