--- old/src/share/vm/c1/c1_LIRGenerator.cpp 2016-08-26 15:43:19.895278592 +0200 +++ new/src/share/vm/c1/c1_LIRGenerator.cpp 2016-08-26 15:43:19.771278598 +0200 @@ -2410,6 +2410,15 @@ #endif // INCLUDE_ALL_GCS if (x->is_volatile() && os::is_MP()) __ membar_acquire(); + + /* Normalize boolean value returned by unsafe operation, i.e., value != 0 ? value = true : value false. */ + if (type == T_BOOLEAN) { + LabelObj* equalZeroLabel = new LabelObj(); + __ cmp(lir_cond_equal, value, 0); + __ branch(lir_cond_equal, T_BOOLEAN, equalZeroLabel->label()); + __ move(LIR_OprFact::intConst(1), value); + __ branch_destination(equalZeroLabel->label()); + } } --- old/src/share/vm/prims/unsafe.cpp 2016-08-26 15:43:19.927278591 +0200 +++ new/src/share/vm/prims/unsafe.cpp 2016-08-26 15:43:19.775278598 +0200 @@ -150,14 +150,23 @@ } template - T normalize(T x) { + T normalize_for_write(T x) { return x; } - jboolean normalize(jboolean x) { + jboolean normalize_for_write(jboolean x) { return x & 1; } + template + T normalize_for_read(T x) { + return x; + } + + jboolean normalize_for_read(jboolean x) { + return x != 0; + } + /** * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access() */ @@ -196,7 +205,7 @@ T* p = (T*)addr(); - T x = *p; + T x = normalize_for_read(*p); return x; } @@ -207,7 +216,7 @@ T* p = (T*)addr(); - *p = normalize(x); + *p = normalize_for_write(x); } @@ -223,7 +232,7 @@ T x = OrderAccess::load_acquire((volatile T*)p); - return x; + return normalize_for_read(x); } template @@ -232,7 +241,7 @@ T* p = (T*)addr(); - OrderAccess::release_store_fence((volatile T*)p, normalize(x)); + OrderAccess::release_store_fence((volatile T*)p, normalize_for_write(x)); } @@ -256,7 +265,7 @@ jlong* p = (jlong*)addr(); - Atomic::store(normalize(x), p); + Atomic::store(normalize_for_write(x), p); } #endif }; --- /dev/null 2016-08-26 11:23:41.521213300 +0200 +++ new/test/compiler/unsafe/UnsafeOnHeapBooleanTest.java 2016-08-26 15:43:19.783278598 +0200 @@ -0,0 +1,95 @@ +/* + * Copyright (c) 2016, 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 + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/* + * @test + * @bug 8161720 + * @modules java.base/jdk.internal.misc + * @run main/othervm -Xint UnsafeOnHeapBooleanTest 1 + * @run main/othervm -XX:-UseOnStackReplacement -XX:+TieredCompilation -XX:TieredStopAtLevel=3 -Xbatch UnsafeOnHeapBooleanTest 20000 + * @run main/othervm -XX:-UseOnStackReplacement -XX:-TieredCompilation -Xbatch UnsafeOnHeapBooleanTest 20000 + */ + +import java.lang.reflect.Field; +import jdk.internal.misc.Unsafe; + +public class UnsafeOnHeapBooleanTest { + static short static_v; + static boolean bool0 = false, bool1 = false, result = false; + static Unsafe UNSAFE = Unsafe.getUnsafe(); + + public static void test() { + try { + // Write two bytes into the static field + // UnsafeOnHeapBooleanTest.static_v write two values. Both + // bytes correspond to the boolean value 'true'. + Field staticVField = UnsafeOnHeapBooleanTest.class.getDeclaredField("static_v"); + Object base = UNSAFE.staticFieldBase(staticVField); + long offset = UNSAFE.staticFieldOffset(staticVField); + UNSAFE.putShort(base, offset, (short)0x0204); + + // Read two bytes from the static field + // UnsafeOnHeapBooleanTest.static_v (as booleans). + bool0 = UNSAFE.getBoolean(base, offset + 0); + bool1 = UNSAFE.getBoolean(base, offset + 1); + result = bool0 & bool1; + } catch (NoSuchFieldException e) { + throw new RuntimeException("### Test failure: static field UnsafeOnHeapBooleanTest.static_v was not found"); + } + } + + public static void main(String args[]) { + System.out.println("### Test started"); + + if (args.length != 1) { + throw new RuntimeException("### Test failure: test called with incorrect number of arguments"); + } + + try { + for (int i = 0; i < Integer.parseInt(args[0]); i++) { + test(); + } + + // Check if the two 'true' boolean values were normalized + // (i.e., reduced from the range 1...255 to 1). + if (!bool0 || !bool1 || !result) { + System.out.println("Some of the results below are wrong"); + System.out.println("bool0 is: " + bool0); + System.out.println("bool1 is: " + bool1); + System.out.println("bool0 & bool1 is: " + result); + System.out.println("==================================="); + throw new RuntimeException("### Test failed"); + } else { + System.out.println("Test generated correct results"); + System.out.println("bool0 is: " + bool0); + System.out.println("bool1 is: " + bool1); + System.out.println("bool0 & bool1 is: " + result); + System.out.println("==================================="); + } + } catch (NumberFormatException e) { + throw new RuntimeException("### Test failure: test called with incorrectly formatted parameter"); + } + + System.out.println("### Test passed"); + } +} --- old/src/share/vm/opto/library_call.cpp 2016-08-26 15:43:19.955278590 +0200 +++ new/src/share/vm/opto/library_call.cpp 2016-08-26 15:43:19.787278597 +0200 @@ -2471,6 +2471,28 @@ // load value switch (type) { case T_BOOLEAN: + { + // Normalize the value returned by getBoolean in the following cases + if (mismatched || + heap_base_oop == top() || // - heap_base_oop is NULL or + (can_access_non_heap && alias_type->field() == NULL) // - heap_base_oop is potentially NULL + // and the unsafe access is made to large offset + // (i.e., larger than the maximum offset necessary for any + // field access) + ) { + IdealKit ideal = IdealKit(this); +#define __ ideal. + IdealVariable normalized_result(ideal); + __ declarations_done(); + __ set(normalized_result, p); + __ if_then(p, BoolTest::ne, ideal.ConI(0)); + __ set(normalized_result, ideal.ConI(1)); + ideal.end_if(); + final_sync(ideal); + p = __ value(normalized_result); +#undef __ + } + } case T_CHAR: case T_BYTE: case T_SHORT: --- /dev/null 2016-08-26 11:23:41.521213300 +0200 +++ new/test/compiler/unsafe/UnsafeOffHeapBooleanTest.java 2016-08-26 15:43:19.803278597 +0200 @@ -0,0 +1,92 @@ +/* + * Copyright (c) 2016, 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 + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/* + * @test + * @bug 8161720 + * @modules java.base/jdk.internal.misc + * @run main/othervm -Xint UnsafeOffHeapBooleanTest 1 + * @run main/othervm -XX:+TieredCompilation -XX:TieredStopAtLevel=3 -Xbatch UnsafeOffHeapBooleanTest 20000 + * @run main/othervm -XX:-TieredCompilation -Xbatch UnsafeOffHeapBooleanTest 20000 + */ + + +import java.lang.reflect.Field; +import jdk.internal.misc.Unsafe; + +public class UnsafeOffHeapBooleanTest { + static boolean bool0 = false, bool1 = false, result = false; + static Unsafe UNSAFE = Unsafe.getUnsafe(); + static long offHeapMemory; + + public static void test() { + // Write two bytes to the off-heap memory location, both + // bytes correspond to the boolean value 'true'. + UNSAFE.putShort(null, offHeapMemory, (short)0x0204); + + // Read two bytes from the storage allocated above (as booleans). + bool0 = UNSAFE.getBoolean(null, offHeapMemory + 0); + bool1 = UNSAFE.getBoolean(null, offHeapMemory + 1); + result = bool0 & bool1; + } + + public static void main(String args[]) { + System.out.println("### Test started"); + + if (args.length != 1) { + throw new RuntimeException("### Test failure: test called with incorrect number of arguments"); + } + + // Allocate two bytes of storage. + offHeapMemory = UNSAFE.allocateMemory(2); + + try { + for (int i = 0; i < Integer.parseInt(args[0]); i++) { + test(); + } + + // Check if the two 'true' boolean values were normalized + // (i.e., reduced from the range 1...255 to 1). + if (!bool0 || !bool1 || !result) { + System.out.println("Some of the results below are wrong"); + System.out.println("bool0 is: " + bool0); + System.out.println("bool1 is: " + bool1); + System.out.println("bool0 & bool1 is: " + result); + System.out.println("==================================="); + throw new RuntimeException("### Test failed"); + } else { + System.out.println("Test generated correct results"); + System.out.println("bool0 is: " + bool0); + System.out.println("bool1 is: " + bool1); + System.out.println("bool0 & bool1 is: " + result); + System.out.println("==================================="); + } + } catch (NumberFormatException e) { + throw new RuntimeException("### Test failure: test called with incorrectly formatted parameter"); + } + + UNSAFE.freeMemory(offHeapMemory); + + System.out.println("### Test passed"); + } +} --- /dev/null 2016-08-26 11:23:41.521213300 +0200 +++ new/test/compiler/unsafe/UnsafeSmallOffsetBooleanAccessTest.java 2016-08-26 15:43:19.803278597 +0200 @@ -0,0 +1,85 @@ +/* + * Copyright (c) 2016, 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 + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + */ + +/* + * @test + * @bug 8161720 + * @modules java.base/jdk.internal.misc + * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -Xbatch -XX:-TieredCompilation UnsafeSmallOffsetBooleanAccessTest + * @run main/othervm -Xbatch UnsafeSmallOffsetBooleanAccessTest + */ + +import java.util.Random; +import jdk.internal.misc.Unsafe; + +public class UnsafeSmallOffsetBooleanAccessTest { + static final Unsafe UNSAFE = Unsafe.getUnsafe(); + static final long F_OFFSET; + static final Random random = new Random(); + + static { + try { + F_OFFSET = UNSAFE.objectFieldOffset(T.class.getDeclaredField("f")); + System.out.println("The offset is: " + F_OFFSET); + } catch (Exception e) { + throw new Error(e); + } + } + + static class T { + boolean f; + } + + // Always return false in a way that is not obvious to the compiler. + public static boolean myRandom() { + if (random.nextInt(101) > 134) { + return true; + } else { + return false; + } + } + + public static boolean test(T t) { + boolean result = false; + for (int i = 0; i < 20000; i++) { + boolean random = myRandom(); + // If myRandom() returns false, access t.f. + // + // If myRandom() returns true, access virtual address + // F_OFFSET. That address is most likely not mapped, + // therefore the access will most likely cause a + // crash. We're not concerned about that, though, because + // myRandom() always returns false. However, the C2 + // compiler avoids normalization of the value returned by + // getBoolean in this case. + result = UNSAFE.getBoolean(myRandom() ? null : t, F_OFFSET); + } + return result; + } + + public static void main(String[] args) { + T t = new T(); + UNSAFE.putBoolean(t, F_OFFSET, true); + System.out.println("The result for t is: " + test(t)); + } +}