Skip direct map from apk check for pre-KitKat Samsung.

base/android/java/src/org/chromium/base/library_loader/Linker.java

Index: base/android/java/src/org/chromium/base/library_loader/Linker.java
diff --git a/base/android/java/src/org/chromium/base/library_loader/Linker.java b/base/android/java/src/org/chromium/base/library_loader/Linker.java
index dfcc14156bbdc857e8d1efea52ea498fafc44d24..12c76f38401611188ecec2bdd38c17018d6475c6 100644
--- a/base/android/java/src/org/chromium/base/library_loader/Linker.java
+++ b/base/android/java/src/org/chromium/base/library_loader/Linker.java
@@ -16,9 +16,13 @@ import org.chromium.base.SysUtils;
 import org.chromium.base.ThreadUtils;
 
 import java.io.FileNotFoundException;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 
 import javax.annotation.Nullable;
 
@@ -190,6 +194,28 @@ public class Linker {
     // for testing by calling setMemoryDeviceConfig().
     private static int sMemoryDeviceConfig = MEMORY_DEVICE_CONFIG_INIT;
 
+    // List of devices for which we suppress the test for support for mapping
+    // the APK file with executable permission. This test triggers a warning
+    // on some devices. Devices must be listed in all uppercase only, on the
+    // working assumption that no two distinct actual devices would have model
+    // strings that differ only in character case.
+    //
+    // For more, see:
+    //   https://code.google.com/p/chromium/issues/detail?id=448084
+    private static final String[] MAP_CHECK_BLACKLIST = {
+            "SCH-P709", "GT-I9158", "GT-I9152", "GT-I9150", "GT-I9200X",
+            "SGH-M819N", "SCH-R960", "SPH-L600", "SGH-I527M", "SGH-I527",
+            "SCH-P729", "SHV-E310L", "SHV-E310S", "SHV-E310K", "GT-I9208",
+            "GT-I9205", "GT-I9200"};
+
+    // The blacklist is only used if the OS version code indicates that it
+    // pre-dates an expiry version code.
+    private static final int MAP_CHECK_BLACKLIST_EXPIRY =
+            android.os.Build.VERSION_CODES.KITKAT;

[Andrew Hayden (chromium.org), 2015/01/23 14:59:51]

I don't think you can use this on ICS, right? How do we deal with that?

[simonb (inactive), 2015/01/23 16:03:19]

Compile-time constants should be okay.  From:

http://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html

"If a primitive type or a string is defined as a constant and the value is known
at compile time, the compiler replaces the constant name everywhere in the code
with its value. This is called a compile-time constant."

+
+    // Lookup set, lazy-initialized from the MAP_CHECK_BLACKLIST array.
+    private static Set<String> sMapCheckBlacklist = null;
+
     // Becomes true after linker initialization.
     private static boolean sInitialized = false;
 
@@ -846,13 +872,37 @@ public class Linker {
     public static boolean checkMapExecSupport(String apkFile) {
         assert apkFile != null;
 
-        // https://code.google.com/p/chromium/issues/detail?id=448084
-        // Do not check if the device is Samsung Mega.
+        // If the android build version is before a known good release, check
+        // the blacklist for the build model. If the model is listed then
+        // we skip the check for mmap exec support and return false. This avoids
+        // triggering a warning on these devices. The version check is included
+        // because these devices do not show the warning on later OS builds.
+        //
+        // Uses a case-insensitive lookup to ensure nothing is missed. No two
+        // devices will differ in model character case only. We ensure that the
+        // blacklist is populated with uppercased device names.
+        //
+        // For more, see:
+        //   https://code.google.com/p/chromium/issues/detail?id=448084
         final String model = android.os.Build.MODEL;
-        if (model != null && model.equals("GT-I9205")) {
-            if (DEBUG) Log.i(TAG, "checkMapExecSupport: model is '" + model
-                             + "', returning false");
-            return false;
+        final int version = android.os.Build.VERSION.SDK_INT;
+
+        if (model != null && version < MAP_CHECK_BLACKLIST_EXPIRY) {
+            synchronized (Linker.class) {
+                // Initialize the blacklist lookup set before first use.
+                if (sMapCheckBlacklist == null) {
+                    if (DEBUG) Log.i(TAG, "checkMapExecSupport: initializing blacklist");
+                    final List<String> list = Arrays.asList(MAP_CHECK_BLACKLIST);
+                    sMapCheckBlacklist = new HashSet<String>(list);
+                }
+            }
+
+            // Search the blacklist for the model reported by the OS.
+            if (sMapCheckBlacklist.contains(model.toUpperCase())) {
+                if (DEBUG) Log.i(TAG, "checkMapExecSupport: " + model
+                        + ": model is blacklisted, returning false");
+                return false;
+            }
         }
 
         synchronized (Linker.class) {