src/os_cpu/linux_x86/vm/threadLS_linux_x86.hpp

Wed, 25 Sep 2013 13:58:13 +0200

author
dsimms
date
Wed, 25 Sep 2013 13:58:13 +0200
changeset 5781
899ecf76b570
parent 2995
65dba8692db7
child 6876
710a3c8b516e
permissions
-rw-r--r--

8023956: Provide a work-around to broken Linux 32 bit "Exec Shield" using CS for NX emulation (crashing with SI_KERNEL)
Summary: Execute some code at a high virtual address value, and keep mapped
Reviewed-by: coleenp, zgu

     1 /*
     2  * Copyright (c) 1999, 2010, 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  */
    25 #ifndef OS_CPU_LINUX_X86_VM_THREADLS_LINUX_X86_HPP
    26 #define OS_CPU_LINUX_X86_VM_THREADLS_LINUX_X86_HPP
    28   // Processor dependent parts of ThreadLocalStorage
    30 #if !defined(AMD64) && !defined(MINIMIZE_RAM_USAGE)
    32   // map stack pointer to thread pointer - see notes in threadLS_linux_x86.cpp
    33   #define SP_BITLENGTH  32
    34   #define PAGE_SHIFT    12
    35   #define PAGE_SIZE     (1UL << PAGE_SHIFT)
    36   static Thread* _sp_map[1UL << (SP_BITLENGTH - PAGE_SHIFT)];
    38 public:
    40   static Thread** sp_map_addr() { return _sp_map; }
    42   static Thread* thread() {
    43     uintptr_t sp;
    44     __asm__ volatile ("movl %%esp, %0" : "=r" (sp));
    45     return _sp_map[sp >> PAGE_SHIFT];
    46   }
    48 #else
    50 public:
    52    static Thread* thread() {
    53      return (Thread*) os::thread_local_storage_at(thread_index());
    54    }
    56 #endif // AMD64 || MINIMIZE_RAM_USAGE
    58 #endif // OS_CPU_LINUX_X86_VM_THREADLS_LINUX_X86_HPP

mercurial