1 files changed, 47 insertions, 1 deletions

diff --git a/android/os/ZygoteProcess.java b/android/os/ZygoteProcess.java
index b9dd376f..673da507 100644
--- a/android/os/ZygoteProcess.java
+++ b/android/os/ZygoteProcess.java
@@ -166,6 +166,11 @@ public class ZygoteProcess {
     private List<String> mApiBlacklistExemptions = Collections.emptyList();
 
     /**
+     * Proportion of hidden API accesses that should be logged to the event log; 0 - 0x10000.
+     */
+    private int mHiddenApiAccessLogSampleRate;
+
+    /**
      * The state of the connection to the primary zygote.
      */
     private ZygoteState primaryZygoteState;
@@ -467,7 +472,8 @@ public class ZygoteProcess {
      * <p>The list of exemptions will take affect for all new processes forked from the zygote after
      * this call.
      *
-     * @param exemptions List of hidden API exemption prefixes.
+     * @param exemptions List of hidden API exemption prefixes. Any matching members are treated as
+     *        whitelisted/public APIs (i.e. allowed, no logging of usage).
      */
     public void setApiBlacklistExemptions(List<String> exemptions) {
         synchronized (mLock) {
@@ -477,6 +483,21 @@ public class ZygoteProcess {
         }
     }
 
+    /**
+     * Set the precentage of detected hidden API accesses that are logged to the event log.
+     *
+     * <p>This rate will take affect for all new processes forked from the zygote after this call.
+     *
+     * @param rate An integer between 0 and 0x10000 inclusive. 0 means no event logging.
+     */
+    public void setHiddenApiAccessLogSampleRate(int rate) {
+        synchronized (mLock) {
+            mHiddenApiAccessLogSampleRate = rate;
+            maybeSetHiddenApiAccessLogSampleRate(primaryZygoteState);
+            maybeSetHiddenApiAccessLogSampleRate(secondaryZygoteState);
+        }
+    }
+
     @GuardedBy("mLock")
     private void maybeSetApiBlacklistExemptions(ZygoteState state, boolean sendIfEmpty) {
         if (state == null || state.isClosed()) {
@@ -504,6 +525,29 @@ public class ZygoteProcess {
         }
     }
 
+    private void maybeSetHiddenApiAccessLogSampleRate(ZygoteState state) {
+        if (state == null || state.isClosed()) {
+            return;
+        }
+        if (mHiddenApiAccessLogSampleRate == -1) {
+            return;
+        }
+        try {
+            state.writer.write(Integer.toString(1));
+            state.writer.newLine();
+            state.writer.write("--hidden-api-log-sampling-rate="
+                    + Integer.toString(mHiddenApiAccessLogSampleRate));
+            state.writer.newLine();
+            state.writer.flush();
+            int status = state.inputStream.readInt();
+            if (status != 0) {
+                Slog.e(LOG_TAG, "Failed to set hidden API log sampling rate; status " + status);
+            }
+        } catch (IOException ioe) {
+            Slog.e(LOG_TAG, "Failed to set hidden API log sampling rate", ioe);
+        }
+    }
+
     /**
      * Tries to open socket to Zygote process if not already open. If
      * already open, does nothing.  May block and retry.  Requires that mLock be held.
@@ -519,6 +563,7 @@ public class ZygoteProcess {
                 throw new ZygoteStartFailedEx("Error connecting to primary zygote", ioe);
             }
             maybeSetApiBlacklistExemptions(primaryZygoteState, false);
+            maybeSetHiddenApiAccessLogSampleRate(primaryZygoteState);
         }
         if (primaryZygoteState.matches(abi)) {
             return primaryZygoteState;
@@ -532,6 +577,7 @@ public class ZygoteProcess {
                 throw new ZygoteStartFailedEx("Error connecting to secondary zygote", ioe);
             }
             maybeSetApiBlacklistExemptions(secondaryZygoteState, false);
+            maybeSetHiddenApiAccessLogSampleRate(secondaryZygoteState);
         }
 
         if (secondaryZygoteState.matches(abi)) {