platform_system_sepolicy/private/traced.te
Primiano Tucci 5d31732612 perfetto: allow traced to write into FDs received by the client
This allows an optimization that consists in the "perfetto" cmdline
client passing directly the file descriptor for the output trace
to traced (as opposite to having traced streaming back the trace
data to "perfetto" and having that one doing the write() into file).
This reduces sensibly the memory traffic and CPU overhead of traces
with a minor change.

Bug: 73625179
Test: builds + perfetto_integrationtests w/ long_trace.cfg
Change-Id: I81f5a230338ced20dc543fd91c5a0bd0e58725f2
2018-03-26 01:01:31 +00:00

60 lines
2.1 KiB
Text

# Perfetto user-space tracing daemon (unprivileged)
type traced, domain, coredomain, mlstrustedsubject;
type traced_exec, exec_type, file_type;
# Allow init to exec the daemon.
init_daemon_domain(traced)
# Allow apps in other MLS contexts (for multi-user) to access
# share memory buffers created by traced.
typeattribute traced_tmpfs mlstrustedobject;
# Allow traced to start with a lower scheduling class and change
# class accordingly to what defined in the config provided by
# the privileged process that controls it.
allow traced self:global_capability_class_set { sys_nice };
# Allow to pass a file descriptor for the output trace from "perfetto" (the
# cmdline client) and other shell binaries to traced and let traced write
# directly into that (rather than returning the trace contents over the socket).
allow traced perfetto:fd use;
allow traced shell:fd use;
allow traced perfetto_traces_data_file:file { read write };
###
### Neverallow rules
###
### traced should NEVER do any of this
# Disallow mapping executable memory (execstack and exec are already disallowed
# globally in domain.te).
neverallow traced self:process execmem;
# Block device access.
neverallow traced dev_type:blk_file { read write };
# ptrace any other process
neverallow traced domain:process ptrace;
# Disallows access to /data files, still allowing to write to file descriptors
# passed through the socket.
neverallow traced {
data_file_type
-system_data_file
# TODO(b/72998741) Remove vendor_data_file exemption. Further restricted in a
# subsequent neverallow. Currently only getattr and search are allowed.
-vendor_data_file
-zoneinfo_data_file
}:dir *;
neverallow traced { system_data_file }:dir ~{ getattr search };
neverallow traced zoneinfo_data_file:dir ~r_dir_perms;
neverallow traced { data_file_type -zoneinfo_data_file }:lnk_file *;
neverallow traced {
data_file_type
-zoneinfo_data_file
-perfetto_traces_data_file
}:file ~write;
# Only init is allowed to enter the traced domain via exec()
neverallow { domain -init } traced:process transition;
neverallow * traced:process dyntransition;