2 files changed, 54 insertions, 0 deletions

diff --git a/core/java/android/os/ZygoteProcess.java b/core/java/android/os/ZygoteProcess.java
index d1d5d8e460e8..673da507788f 100644
--- a/core/java/android/os/ZygoteProcess.java
+++ b/core/java/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;
@@ -478,6 +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()) {
@@ -505,6 +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.
@@ -520,6 +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;
@@ -533,6 +577,7 @@ public class ZygoteProcess {
                 throw new ZygoteStartFailedEx("Error connecting to secondary zygote", ioe);
             }
             maybeSetApiBlacklistExemptions(secondaryZygoteState, false);
+            maybeSetHiddenApiAccessLogSampleRate(secondaryZygoteState);
         }
 
         if (secondaryZygoteState.matches(abi)) {
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 60bbb10de014..cbc1e3b9f8bd 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -11749,6 +11749,15 @@ public final class Settings {
                 "hidden_api_blacklist_exemptions";
 
         /**
+         * Sampling rate for hidden API access event logs, as an integer in the range 0 to 0x10000
+         * inclusive.
+         *
+         * @hide
+         */
+        public static final String HIDDEN_API_ACCESS_LOG_SAMPLING_RATE =
+                "hidden_api_access_log_sampling_rate";
+
+        /**
          * Hidden API enforcement policy for apps targeting SDK versions prior to the latest
          * version.
          *