8141491: Unaligned memory access in Bits.c

Summary: Introduce alignment-safe Copy::conjoint_swap and JVM_CopySwapMemory
Reviewed-by: mikael, dholmes

make/mapfiles/libjava/mapfile-vers

 #
-# Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -222,12 +222,7 @@ SUNWprivate_1.1 {
 		Java_java_lang_UNIXProcess_waitForProcessExit;
 		Java_java_lang_UNIXProcess_forkAndExec;
 		Java_java_lang_UNIXProcess_destroyProcess;
-                Java_java_nio_Bits_copyFromShortArray;
-                Java_java_nio_Bits_copyToShortArray;
-                Java_java_nio_Bits_copyFromIntArray;
-                Java_java_nio_Bits_copyToIntArray;
-                Java_java_nio_Bits_copyFromLongArray;
-                Java_java_nio_Bits_copyToLongArray;
+                Java_java_nio_Bits_copySwapMemory0;
 		Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedAction_2;
 		Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedAction_2Ljava_security_AccessControlContext_2;
 		Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedExceptionAction_2;

src/share/classes/java/nio/Bits.java

 /*
- * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -835,31 +835,191 @@ class Bits {                            // package-private
         }
     }
 
-    static void copyFromCharArray(Object src, long srcPos, long dstAddr,
-                                  long length)
-    {
-        copyFromShortArray(src, srcPos, dstAddr, length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 16-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromCharArray(Object src, long srcPos, long dstAddr, long length) {
+        copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 2);
     }
 
-    static void copyToCharArray(long srcAddr, Object dst, long dstPos,
-                                long length)
-    {
-        copyToShortArray(srcAddr, dst, dstPos, length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 16-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToCharArray(long srcAddr, Object dst, long dstPos, long length) {
+        copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 2);
     }
 
-    static native void copyFromShortArray(Object src, long srcPos, long dstAddr,
-                                          long length);
-    static native void copyToShortArray(long srcAddr, Object dst, long dstPos,
-                                        long length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 16-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromShortArray(Object src, long srcPos, long dstAddr, long length) {
+        copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 2);
+    }
 
-    static native void copyFromIntArray(Object src, long srcPos, long dstAddr,
-                                        long length);
-    static native void copyToIntArray(long srcAddr, Object dst, long dstPos,
-                                      long length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 16-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToShortArray(long srcAddr, Object dst, long dstPos, long length) {
+        copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 2);
+    }
+
+    /**
+     * Copy and unconditionally byte swap 32 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 32-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromIntArray(Object src, long srcPos, long dstAddr, long length) {
+        copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 4);
+    }
+
+    /**
+     * Copy and unconditionally byte swap 32 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 32-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToIntArray(long srcAddr, Object dst, long dstPos, long length) {
+        copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 4);
+    }
 
-    static native void copyFromLongArray(Object src, long srcPos, long dstAddr,
-                                         long length);
-    static native void copyToLongArray(long srcAddr, Object dst, long dstPos,
-                                       long length);
+    /**
+     * Copy and unconditionally byte swap 64 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 64-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromLongArray(Object src, long srcPos, long dstAddr, long length) {
+        copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 8);
+    }
+
+    /**
+     * Copy and unconditionally byte swap 64 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 64-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToLongArray(long srcAddr, Object dst, long dstPos, long length) {
+        copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 8);
+    }
+
+    private static boolean isPrimitiveArray(Class<?> c) {
+        Class<?> componentType = c.getComponentType();
+        return componentType != null && componentType.isPrimitive();
+    }
+
+    private native static void copySwapMemory0(Object srcBase, long srcOffset,
+                                        Object destBase, long destOffset,
+                                        long bytes, long elemSize);
+
+    /**
+     * Copies all elements from one block of memory to another block,
+     * *unconditionally* byte swapping the elements on the fly.
+     *
+     * <p>This method determines each block's base address by means of two parameters,
+     * and so it provides (in effect) a <em>double-register</em> addressing mode,
+     * as discussed in {@link sun.misc.Unsafe#getInt(Object,long)}.  When the
+     * object reference is null, the offset supplies an absolute base address.
+     *
+     * @since 8u201
+     */
+    private static void copySwapMemory(Object srcBase, long srcOffset,
+                               Object destBase, long destOffset,
+                               long bytes, long elemSize) {
+        if (bytes < 0) {
+            throw new IllegalArgumentException();
+        }
+        if (elemSize != 2 && elemSize != 4 && elemSize != 8) {
+            throw new IllegalArgumentException();
+        }
+        if (bytes % elemSize != 0) {
+            throw new IllegalArgumentException();
+        }
+        if ((srcBase == null && srcOffset == 0) ||
+            (destBase == null && destOffset == 0)) {
+            throw new NullPointerException();
+        }
+
+        // Must be off-heap, or primitive heap arrays
+        if (srcBase != null && (srcOffset < 0 || !isPrimitiveArray(srcBase.getClass()))) {
+            throw new IllegalArgumentException();
+        }
+        if (destBase != null && (destOffset < 0 || !isPrimitiveArray(destBase.getClass()))) {
+            throw new IllegalArgumentException();
+        }
+
+        // Sanity check size and offsets on 32-bit platforms. Most
+        // significant 32 bits must be zero.
+        if (unsafe.addressSize() == 4 &&
+            (bytes >>> 32 != 0 || srcOffset >>> 32 != 0 || destOffset >>> 32 != 0)) {
+            throw new IllegalArgumentException();
+        }
+
+        if (bytes == 0) {
+            return;
+        }
+
+        copySwapMemory0(srcBase, srcOffset, destBase, destOffset, bytes, elemSize);
+    }
 
 }

src/share/javavm/export/jvm.h

 /*
- * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -117,6 +117,14 @@ JVM_InitProperties(JNIEnv *env, jobject p);
 JNIEXPORT void JNICALL
 JVM_OnExit(void (*func)(void));
 
+/*
+ * java.nio.Bits
+ */
+JNIEXPORT void JNICALL
+JVM_CopySwapMemory(JNIEnv *env, jobject srcObj, jlong srcOffset,
+                   jobject dstObj, jlong dstOffset, jlong size,
+                   jlong elemSize);
+
 /*
  * java.lang.Runtime
  */

src/share/native/java/nio/Bits.c

 /*
- * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,259 +23,13 @@
  * questions.
  */
 
-/*
- */
-
-#include "jni.h"
-#include "jni_util.h"
-#include "jlong.h"
-#include <string.h>
-
-/*
- * WARNING:
- *
- * Do not replace instances of:
- *
- *   if (length > MBYTE)
- *     size = MBYTE;
- *   else
- *     size = length;
- *
- * with
- *
- *   size = (length > MBYTE ? MBYTE : length);
- *
- * This expression causes a c compiler assertion failure when compiling on
- * 32-bit sparc.
- */
-
-#define MBYTE 1048576
-
-#define GETCRITICAL_OR_RETURN(bytes, env, obj) { \
-    bytes = (*env)->GetPrimitiveArrayCritical(env, obj, NULL); \
-    if (bytes == NULL)  { \
-        if ((*env)->ExceptionOccurred(env) == NULL) \
-            JNU_ThrowInternalError(env, "Unable to get array"); \
-        return; \
-    } \
-}
-
-#define RELEASECRITICAL(bytes, env, obj, mode) { \
-    (*env)->ReleasePrimitiveArrayCritical(env, obj, bytes, mode); \
-}
-
-#define SWAPSHORT(x) ((jshort)(((x) << 8) | (((x) >> 8) & 0xff)))
-#define SWAPINT(x)   ((jint)((SWAPSHORT((jshort)(x)) << 16) | \
-                            (SWAPSHORT((jshort)((x) >> 16)) & 0xffff)))
-#define SWAPLONG(x)  ((jlong)(((jlong)SWAPINT((jint)(x)) << 32) | \
-                              ((jlong)SWAPINT((jint)((x) >> 32)) & 0xffffffff)))
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyFromShortArray(JNIEnv *env, jobject this, jobject src,
-                                      jlong srcPos, jlong dstAddr, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jshort *srcShort, *dstShort, *endShort;
-    jshort tmpShort;
-
-    dstShort = (jshort *)jlong_to_ptr(dstAddr);
-
-    while (length > 0) {
-        /* do not change this if-else statement, see WARNING above */
-        if (length > MBYTE)
-            size = MBYTE;
-        else
-            size = (size_t)length;
-
-        GETCRITICAL_OR_RETURN(bytes, env, src);
-
-        srcShort = (jshort *)(bytes + srcPos);
-        endShort = srcShort + (size / sizeof(jshort));
-        while (srcShort < endShort) {
-          tmpShort = *srcShort++;
-          *dstShort++ = SWAPSHORT(tmpShort);
-        }
-
-        RELEASECRITICAL(bytes, env, src, JNI_ABORT);
-
-        length -= size;
-        dstAddr += size;
-        srcPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyToShortArray(JNIEnv *env, jobject this, jlong srcAddr,
-                                    jobject dst, jlong dstPos, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jshort *srcShort, *dstShort, *endShort;
-    jshort tmpShort;
-
-    srcShort = (jshort *)jlong_to_ptr(srcAddr);
-
-    while (length > 0) {
-        /* do not change this if-else statement, see WARNING above */
-        if (length > MBYTE)
-            size = MBYTE;
-        else
-            size = (size_t)length;
-
-        GETCRITICAL_OR_RETURN(bytes, env, dst);
-
-        dstShort = (jshort *)(bytes + dstPos);
-        endShort = srcShort + (size / sizeof(jshort));
-        while (srcShort < endShort) {
-            tmpShort = *srcShort++;
-            *dstShort++ = SWAPSHORT(tmpShort);
-        }
-
-        RELEASECRITICAL(bytes, env, dst, 0);
-
-        length -= size;
-        srcAddr += size;
-        dstPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyFromIntArray(JNIEnv *env, jobject this, jobject src,
-                                    jlong srcPos, jlong dstAddr, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jint *srcInt, *dstInt, *endInt;
-    jint tmpInt;
-
-    dstInt = (jint *)jlong_to_ptr(dstAddr);
-
-    while (length > 0) {
-        /* do not change this code, see WARNING above */
-        if (length > MBYTE)
-            size = MBYTE;
-        else
-            size = (size_t)length;
-
-        GETCRITICAL_OR_RETURN(bytes, env, src);
-
-        srcInt = (jint *)(bytes + srcPos);
-        endInt = srcInt + (size / sizeof(jint));
-        while (srcInt < endInt) {
-            tmpInt = *srcInt++;
-            *dstInt++ = SWAPINT(tmpInt);
-        }
-
-        RELEASECRITICAL(bytes, env, src, JNI_ABORT);
-
-        length -= size;
-        dstAddr += size;
-        srcPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyToIntArray(JNIEnv *env, jobject this, jlong srcAddr,
-                                  jobject dst, jlong dstPos, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jint *srcInt, *dstInt, *endInt;
-    jint tmpInt;
-
-    srcInt = (jint *)jlong_to_ptr(srcAddr);
-
-    while (length > 0) {
-        /* do not change this code, see WARNING above */
-        if (length > MBYTE)
-            size = MBYTE;
-        else
-            size = (size_t)length;
-
-        GETCRITICAL_OR_RETURN(bytes, env, dst);
-
-        dstInt = (jint *)(bytes + dstPos);
-        endInt = srcInt + (size / sizeof(jint));
-        while (srcInt < endInt) {
-            tmpInt = *srcInt++;
-            *dstInt++ = SWAPINT(tmpInt);
-        }
-
-        RELEASECRITICAL(bytes, env, dst, 0);
-
-        length -= size;
-        srcAddr += size;
-        dstPos += size;
-    }
-}
+#include "jvm.h"
 
 JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyFromLongArray(JNIEnv *env, jobject this, jobject src,
-                                     jlong srcPos, jlong dstAddr, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jlong *srcLong, *dstLong, *endLong;
-    jlong tmpLong;
-
-    dstLong = (jlong *)jlong_to_ptr(dstAddr);
-
-    while (length > 0) {
-        /* do not change this code, see WARNING above */
-        if (length > MBYTE)
-            size = MBYTE;
-        else
-            size = (size_t)length;
-
-        GETCRITICAL_OR_RETURN(bytes, env, src);
-
-        srcLong = (jlong *)(bytes + srcPos);
-        endLong = srcLong + (size / sizeof(jlong));
-        while (srcLong < endLong) {
-            tmpLong = *srcLong++;
-            *dstLong++ = SWAPLONG(tmpLong);
-        }
-
-        RELEASECRITICAL(bytes, env, src, JNI_ABORT);
-
-        length -= size;
-        dstAddr += size;
-        srcPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyToLongArray(JNIEnv *env, jobject this, jlong srcAddr,
-                                   jobject dst, jlong dstPos, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jlong *srcLong, *dstLong, *endLong;
-    jlong tmpLong;
-
-    srcLong = (jlong *)jlong_to_ptr(srcAddr);
-
-    while (length > 0) {
-        /* do not change this code, see WARNING above */
-        if (length > MBYTE)
-            size = MBYTE;
-        else
-            size = (size_t)length;
-
-        GETCRITICAL_OR_RETURN(bytes, env, dst);
-
-        dstLong = (jlong *)(bytes + dstPos);
-        endLong = srcLong + (size / sizeof(jlong));
-        while (srcLong < endLong) {
-            tmpLong = *srcLong++;
-            *dstLong++ = SWAPLONG(tmpLong);
-        }
-
-        RELEASECRITICAL(bytes, env, dst, 0);
-
-        length -= size;
-        srcAddr += size;
-        dstPos += size;
-    }
+Java_java_nio_Bits_copySwapMemory0(JNIEnv *env, jclass cls, jobject srcObj,
+                                   jlong srcOffset, jobject dstObj,
+                                   jlong dstOffset, jlong size,
+                                   jlong elemSize) {
+  JVM_CopySwapMemory(env, srcObj, srcOffset, dstObj, dstOffset,
+                     size, elemSize);
 }