Set memlock rlimit to 64KB

Defaulting Android to limit memlock to 64KB. This will help preventing
pages from being swapped until the app is killed it's memory will stay
resident. CTS test is enforced only in U+ devies.

Bug: 201797650
Test: Added new test to verify we are memlock at or under 64KB
Change-Id: I5a9e9da12f6df5a056ee47d0593c13e9c779e054

init/init_test.cpp

@@ -21,8 +21,10 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
+#include <android/api-level.h>
 #include <gtest/gtest.h>
 #include <selinux/selinux.h>
+#include <sys/resource.h>
 
 #include "action.h"
 #include "action_manager.h"
@@ -626,6 +628,20 @@ service A something
     ASSERT_EQ(1u, parser.parse_error_count());
 }
 
+TEST(init, MemLockLimit) {
+    // Test is enforced only for U+ devices
+    if (android::base::GetIntProperty("ro.vendor.api_level", 0) < __ANDROID_API_U__) {
+        GTEST_SKIP();
+    }
+
+    // Verify we are running memlock at, or under, 64KB
+    const unsigned long max_limit = 65536;
+    struct rlimit curr_limit;
+    ASSERT_EQ(getrlimit(RLIMIT_MEMLOCK, &curr_limit), 0);
+    ASSERT_LE(curr_limit.rlim_cur, max_limit);
+    ASSERT_LE(curr_limit.rlim_max, max_limit);
+}
+
 class TestCaseLogger : public ::testing::EmptyTestEventListener {
     void OnTestStart(const ::testing::TestInfo& test_info) override {
 #ifdef __ANDROID__

rootdir/init.rc

@@ -47,6 +47,9 @@ on early-init
     # Allow up to 32K FDs per process
     setrlimit nofile 32768 32768
 
+    # set RLIMIT_MEMLOCK to 64KB
+    setrlimit memlock 65536 65536
+
     # Set up linker config subdirectories based on mount namespaces
     mkdir /linkerconfig/bootstrap 0755
     mkdir /linkerconfig/default 0755