Corrected buffer overflow when parsing /proc/wakelocks

The android_os_Process_parseProcLineArray in android_util_Process.cpp
writes up to buffer[endIndex]. This sometimes caused an assert to be
triggered in NewStringUTF when the output from /proc/wakelocks was
larger than 4096 bytes. The buffer was also increased in order to be
able to parse all wakelocks completely.

Change-Id: Idf8e66d61ad979377569048f59c3eee278b146db

Author: Johannes Carlsson

core/java/com/android/internal/os/BatteryStatsImpl.java

@@ -844,7 +844,7 @@ void readSummaryFromParcelLocked(Parcel in) {
 
     private final Map<String, KernelWakelockStats> readKernelWakelockStats() {
 
-        byte[] buffer = new byte[4096];
+        byte[] buffer = new byte[8192];
         int len;
 
         try {
@@ -891,9 +891,11 @@ private final Map<String, KernelWakelockStats> parseProcWakelocks(
                 for (endIndex=startIndex; 
                         endIndex < len && wlBuffer[endIndex] != '\n' && wlBuffer[endIndex] != '\0'; 
                         endIndex++);
-                // Don't go over the end of the buffer
-                if (endIndex < len) {
-                    endIndex++; // endIndex is an exclusive upper bound.
+                endIndex++; // endIndex is an exclusive upper bound.
+                // Don't go over the end of the buffer, Process.parseProcLine might
+                // write to wlBuffer[endIndex]
+                if (endIndex >= (len - 1) ) {
+                    return m;
                 }
 
                 String[] nameStringArray = mProcWakelocksName;