Merge "Add memfd_create to android.system.Os"

9 files changed, 97 insertions, 0 deletions

diff --git a/luni/src/main/java/android/system/Os.java b/luni/src/main/java/android/system/Os.java
index cc6b0a56d5..4c258c69e2 100644
--- a/luni/src/main/java/android/system/Os.java
+++ b/luni/src/main/java/android/system/Os.java
@@ -362,6 +362,11 @@ public final class Os {
     public static StructStat lstat(String path) throws ErrnoException { return Libcore.os.lstat(path); }
 
     /**
+     * See <a href="http://man7.org/linux/man-pages/man2/memfd_create.2.html">memfd_create(2)</a>.
+     */
+    public static @NonNull FileDescriptor memfd_create(@NonNull String name, int flags) throws ErrnoException { return Libcore.os.memfd_create(name, flags); }
+
+    /**
      * See <a href="http://man7.org/linux/man-pages/man2/mincore.2.html">mincore(2)</a>.
      */
     public static void mincore(long address, long byteCount, byte[] vector) throws ErrnoException { Libcore.os.mincore(address, byteCount, vector); }
diff --git a/luni/src/main/java/android/system/OsConstants.java b/luni/src/main/java/android/system/OsConstants.java
index 9daccc697d..d8745511c2 100644
--- a/luni/src/main/java/android/system/OsConstants.java
+++ b/luni/src/main/java/android/system/OsConstants.java
@@ -374,6 +374,7 @@ public final class OsConstants {
     public static final int MCAST_UNBLOCK_SOURCE = placeholder();
     public static final int MCL_CURRENT = placeholder();
     public static final int MCL_FUTURE = placeholder();
+    public static final int MFD_CLOEXEC = placeholder();
     public static final int MSG_CTRUNC = placeholder();
     public static final int MSG_DONTROUTE = placeholder();
     public static final int MSG_EOR = placeholder();
diff --git a/luni/src/main/java/libcore/io/ForwardingOs.java b/luni/src/main/java/libcore/io/ForwardingOs.java
index c82cbe0fa3..c75f94e4ad 100644
--- a/luni/src/main/java/libcore/io/ForwardingOs.java
+++ b/luni/src/main/java/libcore/io/ForwardingOs.java
@@ -150,6 +150,7 @@ public class ForwardingOs implements Os {
     public long lseek(FileDescriptor fd, long offset, int whence) throws ErrnoException { return os.lseek(fd, offset, whence); }
     @UnsupportedAppUsage
     public StructStat lstat(String path) throws ErrnoException { return os.lstat(path); }
+    public FileDescriptor memfd_create(String name, int flags) throws ErrnoException { return os.memfd_create(name, flags); }
     public void mincore(long address, long byteCount, byte[] vector) throws ErrnoException { os.mincore(address, byteCount, vector); }
     @UnsupportedAppUsage
     public void mkdir(String path, int mode) throws ErrnoException { os.mkdir(path, mode); }
diff --git a/luni/src/main/java/libcore/io/Linux.java b/luni/src/main/java/libcore/io/Linux.java
index e2a4c548d4..74608d392a 100644
--- a/luni/src/main/java/libcore/io/Linux.java
+++ b/luni/src/main/java/libcore/io/Linux.java
@@ -121,6 +121,7 @@ public final class Linux implements Os {
     public native String[] listxattr(String path) throws ErrnoException;
     public native long lseek(FileDescriptor fd, long offset, int whence) throws ErrnoException;
     public native StructStat lstat(String path) throws ErrnoException;
+    public native FileDescriptor memfd_create(String name, int flags) throws ErrnoException;
     public native void mincore(long address, long byteCount, byte[] vector) throws ErrnoException;
     public native void mkdir(String path, int mode) throws ErrnoException;
     public native void mkfifo(String path, int mode) throws ErrnoException;
diff --git a/luni/src/main/java/libcore/io/Os.java b/luni/src/main/java/libcore/io/Os.java
index a7bae10450..048a973778 100644
--- a/luni/src/main/java/libcore/io/Os.java
+++ b/luni/src/main/java/libcore/io/Os.java
@@ -123,6 +123,7 @@ public interface Os {
     public String[] listxattr(String path) throws ErrnoException;
     public long lseek(FileDescriptor fd, long offset, int whence) throws ErrnoException;
     public StructStat lstat(String path) throws ErrnoException;
+    public FileDescriptor memfd_create(String name, int flags) throws ErrnoException;
     public void mincore(long address, long byteCount, byte[] vector) throws ErrnoException;
     public void mkdir(String path, int mode) throws ErrnoException;
     public void mkfifo(String path, int mode) throws ErrnoException;
diff --git a/luni/src/main/native/android_system_OsConstants.cpp b/luni/src/main/native/android_system_OsConstants.cpp
index 31ef37da3c..6cf2c8b30b 100644
--- a/luni/src/main/native/android_system_OsConstants.cpp
+++ b/luni/src/main/native/android_system_OsConstants.cpp
@@ -375,6 +375,9 @@ static void OsConstants_initConstants(JNIEnv* env, jclass c) {
 #endif
     initConstant(env, c, "MCL_CURRENT", MCL_CURRENT);
     initConstant(env, c, "MCL_FUTURE", MCL_FUTURE);
+#if defined(MFD_CLOEXEC)
+    initConstant(env, c, "MFD_CLOEXEC", MFD_CLOEXEC);
+#endif
     initConstant(env, c, "MSG_CTRUNC", MSG_CTRUNC);
     initConstant(env, c, "MSG_DONTROUTE", MSG_DONTROUTE);
     initConstant(env, c, "MSG_EOR", MSG_EOR);
diff --git a/luni/src/main/native/libcore_io_Linux.cpp b/luni/src/main/native/libcore_io_Linux.cpp
index 805b32fb47..9e44e63fe4 100644
--- a/luni/src/main/native/libcore_io_Linux.cpp
+++ b/luni/src/main/native/libcore_io_Linux.cpp
@@ -1837,6 +1837,21 @@ static jobject Linux_lstat(JNIEnv* env, jobject, jstring javaPath) {
     return doStat(env, javaPath, true);
 }
 
+static jobject Linux_memfd_create(JNIEnv* env, jobject, jstring javaName, jint flags) {
+#if defined(__BIONIC__)
+    ScopedUtfChars name(env, javaName);
+    if (name.c_str() == NULL) {
+        return NULL;
+    }
+
+    int fd = throwIfMinusOne(env, "memfd_create", memfd_create(name.c_str(), flags));
+    return fd != -1 ? jniCreateFileDescriptor(env, fd) : NULL;
+#else
+    UNUSED(env, javaName, flags);
+    return NULL;
+#endif
+}
+
 static void Linux_mincore(JNIEnv* env, jobject, jlong address, jlong byteCount, jbyteArray javaVector) {
     ScopedByteArrayRW vector(env, javaVector);
     if (vector.get() == NULL) {
@@ -2623,6 +2638,7 @@ static JNINativeMethod gMethods[] = {
     NATIVE_METHOD(Linux, listxattr, "(Ljava/lang/String;)[Ljava/lang/String;"),
     NATIVE_METHOD(Linux, lseek, "(Ljava/io/FileDescriptor;JI)J"),
     NATIVE_METHOD(Linux, lstat, "(Ljava/lang/String;)Landroid/system/StructStat;"),
+    NATIVE_METHOD(Linux, memfd_create, "(Ljava/lang/String;I)Ljava/io/FileDescriptor;"),
     NATIVE_METHOD(Linux, mincore, "(JJ[B)V"),
     NATIVE_METHOD(Linux, mkdir, "(Ljava/lang/String;I)V"),
     NATIVE_METHOD(Linux, mkfifo, "(Ljava/lang/String;I)V"),
diff --git a/luni/src/test/java/libcore/android/system/OsTest.java b/luni/src/test/java/libcore/android/system/OsTest.java
index a56ff000b9..25d56bcbc3 100644
--- a/luni/src/test/java/libcore/android/system/OsTest.java
+++ b/luni/src/test/java/libcore/android/system/OsTest.java
@@ -1481,4 +1481,72 @@ public class OsTest extends TestCase {
         assertTrue(address > 0);
         Os.munmap(address, size);
     }
+
+    public void testMemfdCreate() throws Exception {
+        FileDescriptor fd = null;
+        try {
+            fd = Os.memfd_create("test_memfd", 0);
+            assertNotNull(fd);
+            assertTrue(fd.valid());
+
+            StructStat stat = Os.fstat(fd);
+            assertEquals(0, stat.st_size);
+
+            final byte[] expected = new byte[] {1, 2, 3, 4};
+            Os.write(fd, expected, 0, expected.length);
+            stat = Os.fstat(fd);
+            assertEquals(expected.length, stat.st_size);
+
+            byte[] actual = new byte[expected.length];
+            // should be seekable
+            Os.lseek(fd, 0, SEEK_SET);
+            Os.read(fd, actual, 0, actual.length);
+            assertArrayEquals(expected, actual);
+        } finally {
+            if (fd != null) {
+                Os.close(fd);
+                fd = null;
+            }
+        }
+    }
+
+    public void testMemfdCreateFlags() throws Exception {
+        FileDescriptor fd = null;
+
+        // test that MFD_CLOEXEC is obeyed
+        try {
+            fd = Os.memfd_create("test_memfd", 0);
+            assertNotNull(fd);
+            assertTrue(fd.valid());
+            int flags = Os.fcntlVoid(fd, F_GETFD);
+            assertTrue("Expected flags to not include " + FD_CLOEXEC + ", actual value: " + flags,
+                    0 == (flags & FD_CLOEXEC));
+        } finally {
+            if (fd != null) {
+                Os.close(fd);
+                fd = null;
+            }
+        }
+        try {
+            fd = Os.memfd_create("test_memfd", MFD_CLOEXEC);
+            assertNotNull(fd);
+            assertTrue(fd.valid());
+            int flags = Os.fcntlVoid(fd, F_GETFD);
+            assertTrue("Expected flags to include " + FD_CLOEXEC + ", actual value: " + flags,
+                    0 != (flags & FD_CLOEXEC));
+        } finally {
+            if (fd != null) {
+                Os.close(fd);
+                fd = null;
+            }
+        }
+    }
+
+    public void testMemfdCreateErrno() throws Exception {
+        expectException(() -> Os.memfd_create(null, 0), NullPointerException.class, null,
+                "memfd_create(null, 0)");
+
+        expectException(() -> Os.memfd_create("test_memfd", 0xffff), ErrnoException.class, EINVAL,
+                "memfd_create(\"test_memfd\", 0xffff)");
+    }
 }
diff --git a/luni/src/test/java/libcore/libcore/io/BlockGuardOsTest.java b/luni/src/test/java/libcore/libcore/io/BlockGuardOsTest.java
index 17f031be2a..218678ee56 100644
--- a/luni/src/test/java/libcore/libcore/io/BlockGuardOsTest.java
+++ b/luni/src/test/java/libcore/libcore/io/BlockGuardOsTest.java
@@ -226,6 +226,7 @@ public class BlockGuardOsTest {
                 "kill(int,int)",
                 "listen(java.io.FileDescriptor,int)",
                 "listxattr(java.lang.String)",
+                "memfd_create(java.lang.String,int)",
                 "mincore(long,long,byte[])",
                 "mlock(long,long)",
                 "mmap(long,long,int,int,java.io.FileDescriptor,long)",