initial policy for traced_perf daemon (perf profiler)
The steps involved in setting up profiling and stack unwinding are
described in detail at go/perfetto-perf-android.
To summarize the interesting case: the daemon uses cpu-wide
perf_event_open, with userspace stack and register sampling on. For each
sample, it identifies whether the process is profileable, and obtains
the FDs for /proc/[pid]/{maps,mem} using a dedicated RT signal (with the
bionic signal handler handing over the FDs over a dedicated socket). It
then uses libunwindstack to unwind & symbolize the stacks, sending the
results to the central tracing daemon (traced).
This patch covers the app profiling use-cases. Splitting out the
"profile most things on debug builds" into a separate patch for easier
review.
Most of the exceptions in domain.te & coredomain.te come from the
"vendor_file_type" allow-rule. We want a subset of that (effectively all
libraries/executables), but I believe that in practice it's hard to use
just the specific subtypes, and we're better off allowing access to all
vendor_file_type files.
Bug: 137092007
Change-Id: I4aa482cfb3f9fb2fabf02e1dff92e2b5ce121a47
diff --git a/private/priv_app.te b/private/priv_app.te
index c879c33..16f651a 100644
--- a/private/priv_app.te
+++ b/private/priv_app.te
@@ -123,9 +123,9 @@
binder_call(priv_app, incidentd)
allow priv_app incidentd:fifo_file { read write };
-# Allow heap profiling if the app opts in by being marked
-# profileable/debuggable.
+# Allow profiling if the app opts in by being marked profileable/debuggable.
can_profile_heap(priv_app)
+can_profile_perf(priv_app)
# Allow priv_apps to check whether Dynamic System Update is enabled
get_prop(priv_app, dynamic_system_prop)