os_linux_x86.hpp revision 5776:de6a9e811145
1/* 2 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25#ifndef OS_CPU_LINUX_X86_VM_OS_LINUX_X86_HPP 26#define OS_CPU_LINUX_X86_VM_OS_LINUX_X86_HPP 27 28 static void setup_fpu(); 29 static bool supports_sse(); 30 31 static jlong rdtsc(); 32 33 static bool is_allocatable(size_t bytes); 34 35 // Used to register dynamic code cache area with the OS 36 // Note: Currently only used in 64 bit Windows implementations 37 static bool register_code_area(char *low, char *high) { return true; } 38 39 /* 40 * Work-around for broken NX emulation using CS limit, Red Hat patch "Exec-Shield" 41 * (IA32 only). 42 * 43 * Map and execute at a high VA to prevent CS lazy updates race with SMP MM 44 * invalidation.Further code generation by the JVM will no longer cause CS limit 45 * updates. 46 * 47 * Affects IA32: RHEL 5 & 6, Ubuntu 10.04 (LTS), 10.10, 11.04, 11.10, 12.04. 48 * @see JDK-8023956 49 */ 50 static void workaround_expand_exec_shield_cs_limit(); 51 52#endif // OS_CPU_LINUX_X86_VM_OS_LINUX_X86_HPP 53