From 12de0df1b7e7050750624a6625cee1d3cde9694e Mon Sep 17 00:00:00 2001
From: Mitch Phillips <mitchp@google.com>
Date: Mon, 3 Feb 2020 08:43:35 -0800
Subject: [PATCH] [GWP-ASan] Maybe initialise GWP-ASan from Zygote.

Calls the GWP-ASan mallopt() to possibly install GWP-ASan for the zygote
child.

Bug: 135634846
Test: ??
Change-Id: I08d6797fa9b5ca10b97e0ab1efc2dc1c219c1b45
---
 core/jni/com_android_internal_os_Zygote.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/core/jni/com_android_internal_os_Zygote.cpp b/core/jni/com_android_internal_os_Zygote.cpp
index a09c0b38eb2d8..7a93d8db09319 100644
--- a/core/jni/com_android_internal_os_Zygote.cpp
+++ b/core/jni/com_android_internal_os_Zygote.cpp
@@ -579,6 +579,12 @@ static void PreApplicationInit() {
 
   // Set the jemalloc decay time to 1.
   mallopt(M_DECAY_TIME, 1);
+
+  // Maybe initialize GWP-ASan here. Must be called after
+  // mallopt(M_SET_ZYGOTE_CHILD).
+  bool ForceEnableGwpAsan = false;
+  android_mallopt(M_INITIALIZE_GWP_ASAN, &ForceEnableGwpAsan,
+                  sizeof(ForceEnableGwpAsan));
 }
 
 static void SetUpSeccompFilter(uid_t uid, bool is_child_zygote) {