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6968348: Byteswapped memory access can point to wrong location after JIT

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Reviewed-by: twisti, kvn, iveresov
This commit is contained in:
Tom Rodriguez 2010-10-04 17:09:18 -07:00
parent 7cc55737b6
commit f591ed981d
2 changed files with 58 additions and 37 deletions
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37
hotspot/src/cpu/x86/vm/x86_64.ad
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@ -7349,43 +7349,6 @@ instruct bytes_reverse_short(rRegI dst) %{
ins_pipe( ialu_reg );
%}
instruct loadI_reversed(rRegI dst, memory src) %{
match(Set dst (ReverseBytesI (LoadI src)));
format %{ "bswap_movl $dst, $src" %}
opcode(0x8B, 0x0F, 0xC8); /* Opcode 8B 0F C8 */
ins_encode(REX_reg_mem(dst, src), OpcP, reg_mem(dst, src), REX_reg(dst), OpcS, opc3_reg(dst));
ins_pipe( ialu_reg_mem );
%}
instruct loadL_reversed(rRegL dst, memory src) %{
match(Set dst (ReverseBytesL (LoadL src)));
format %{ "bswap_movq $dst, $src" %}
opcode(0x8B, 0x0F, 0xC8); /* Opcode 8B 0F C8 */
ins_encode(REX_reg_mem_wide(dst, src), OpcP, reg_mem(dst, src), REX_reg_wide(dst), OpcS, opc3_reg(dst));
ins_pipe( ialu_reg_mem );
%}
instruct storeI_reversed(memory dst, rRegI src) %{
match(Set dst (StoreI dst (ReverseBytesI src)));
format %{ "movl_bswap $dst, $src" %}
opcode(0x0F, 0xC8, 0x89); /* Opcode 0F C8 89 */
ins_encode( REX_reg(src), OpcP, opc2_reg(src), REX_reg_mem(src, dst), OpcT, reg_mem(src, dst) );
ins_pipe( ialu_mem_reg );
%}
instruct storeL_reversed(memory dst, rRegL src) %{
match(Set dst (StoreL dst (ReverseBytesL src)));
format %{ "movq_bswap $dst, $src" %}
opcode(0x0F, 0xC8, 0x89); /* Opcode 0F C8 89 */
ins_encode( REX_reg_wide(src), OpcP, opc2_reg(src), REX_reg_mem_wide(src, dst), OpcT, reg_mem(src, dst) );
ins_pipe( ialu_mem_reg );
%}
//---------- Zeros Count Instructions ------------------------------------------
instruct countLeadingZerosI(rRegI dst, rRegI src, rFlagsReg cr) %{

58
hotspot/test/compiler/6968348/Test6968348.java Normal file
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@ -0,0 +1,58 @@
/*
* Copyright (c) 2010, 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 6968348
* @summary Byteswapped memory access can point to wrong location after JIT
*
* @run main Test6968348
*/
import sun.misc.Unsafe;
import java.lang.reflect.*;
public class Test6968348 {
static Unsafe unsafe;
static final long[] buffer = new long[4096];
static int array_long_base_offset;
public static void main(String[] args) throws Exception {
Class c = Test6968348.class.getClassLoader().loadClass("sun.misc.Unsafe");
Field f = c.getDeclaredField("theUnsafe");
f.setAccessible(true);
unsafe = (Unsafe)f.get(c);
array_long_base_offset = unsafe.arrayBaseOffset(long[].class);
for (int n = 0; n < 100000; n++) {
test();
}
}
public static void test() {
for (long i = array_long_base_offset; i < 4096; i += 8) {
unsafe.putLong(buffer, i, Long.reverseBytes(i));
}
}
}