Merge "Fix checking if process name is whitelisted" (d900848e) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/am/MemoryStatUtil.java

+20 −3

Original line number	Diff line number	Diff line
		@@ -123,9 +123,8 @@ public final class MemoryStatUtil {
		* if the file is not available.
		*/
		public static String readCmdlineFromProcfs(int pid) {
		String path = String.format(Locale.US, PROC_CMDLINE_FILE_FMT, pid);
		String cmdline = readFileContents(path);
		return cmdline != null ? cmdline : "";
		final String path = String.format(Locale.US, PROC_CMDLINE_FILE_FMT, pid);
		return parseCmdlineFromProcfs(readFileContents(path));
		}

		private static String readFileContents(String path) {
		@@ -210,6 +209,24 @@ public final class MemoryStatUtil {
		return m.find() ? Long.parseLong(m.group(1)) * BYTES_IN_KILOBYTE : 0;
		}


		/**
		* Parses cmdline out of the contents of the /proc/pid/cmdline file in procfs.
		*
		* Parsing is required to strip anything after first null byte.
		*/
		@VisibleForTesting
		static String parseCmdlineFromProcfs(String cmdline) {
		if (cmdline == null) {
		return "";
		}
		int firstNullByte = cmdline.indexOf("\0");
		if (firstNullByte == -1) {
		return cmdline;
		}
		return cmdline.substring(0, firstNullByte);
		}

		/**
		* Returns whether per-app memcg is available on device.
		*/

services/tests/servicestests/src/com/android/server/am/MemoryStatUtilTest.java

+39 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@ import static com.android.server.am.MemoryStatUtil.BYTES_IN_KILOBYTE;
		import static com.android.server.am.MemoryStatUtil.JIFFY_NANOS;
		import static com.android.server.am.MemoryStatUtil.MemoryStat;
		import static com.android.server.am.MemoryStatUtil.PAGE_SIZE;
		import static com.android.server.am.MemoryStatUtil.parseCmdlineFromProcfs;
		import static com.android.server.am.MemoryStatUtil.parseMemoryStatFromMemcg;
		import static com.android.server.am.MemoryStatUtil.parseMemoryStatFromProcfs;
		import static com.android.server.am.MemoryStatUtil.parseVmHWMFromProcfs;
		@@ -31,6 +32,7 @@ import androidx.test.filters.SmallTest;

		import org.junit.Test;

		import java.io.ByteArrayOutputStream;
		import java.util.Collections;

		/**
		@@ -232,4 +234,41 @@ public class MemoryStatUtilTest {

		assertEquals(0, parseVmHWMFromProcfs(null));
		}

		@Test
		public void testParseCmdlineFromProcfs_invalidValue() {
		byte[] nothing = new byte[] {0x00, 0x74, 0x65, 0x73, 0x74}; // \0test

		assertEquals("", parseCmdlineFromProcfs(bytesToString(nothing)));
		}

		@Test
		public void testParseCmdlineFromProcfs_correctValue_noNullBytes() {
		assertEquals("com.google.app", parseCmdlineFromProcfs("com.google.app"));
		}

		@Test
		public void testParseCmdlineFromProcfs_correctValue_withNullBytes() {
		byte[] trailing = new byte[] {0x74, 0x65, 0x73, 0x74, 0x00, 0x00, 0x00}; // test\0\0\0

		assertEquals("test", parseCmdlineFromProcfs(bytesToString(trailing)));

		// test\0\0test
		byte[] inside = new byte[] {0x74, 0x65, 0x73, 0x74, 0x00, 0x00, 0x74, 0x65, 0x73, 0x74};

		assertEquals("test", parseCmdlineFromProcfs(bytesToString(trailing)));
		}

		@Test
		public void testParseCmdlineFromProcfs_emptyContents() {
		assertEquals("", parseCmdlineFromProcfs(""));

		assertEquals("", parseCmdlineFromProcfs(null));
		}

		private static String bytesToString(byte[] bytes) {
		ByteArrayOutputStream output = new ByteArrayOutputStream();
		output.write(bytes, 0, bytes.length);
		return output.toString();
		}
		}