jdk8-mips64-public/hotspot: src/os_cpu/linux_x86/vm/bytes_linux

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_BYTES_LINUX_X86_INLINE_HPP

    26 #define OS_CPU_LINUX_X86_VM_BYTES_LINUX_X86_INLINE_HPP

    28 #include <byteswap.h>

    30 // Efficient swapping of data bytes from Java byte

    31 // ordering to native byte ordering and vice versa.

    32 inline u2   Bytes::swap_u2(u2 x) {

    33 #ifdef AMD64

    34   return bswap_16(x);

    35 #else

    36   u2 ret;

    37   __asm__ __volatile__ (

    38     "movw %0, %%ax;"

    39     "xchg %%al, %%ah;"

    40     "movw %%ax, %0"

    41     :"=r" (ret)      // output : register 0 => ret

    42     :"0"  (x)        // input  : x => register 0

    43     :"ax", "0"       // clobbered registers

    44   );

    45   return ret;

    46 #endif // AMD64

    47 }

    49 inline u4   Bytes::swap_u4(u4 x) {

    50 #ifdef AMD64

    51   return bswap_32(x);

    52 #else

    53   u4 ret;

    54   __asm__ __volatile__ (

    55     "bswap %0"

    56     :"=r" (ret)      // output : register 0 => ret

    57     :"0"  (x)        // input  : x => register 0

    58     :"0"             // clobbered register

    59   );

    60   return ret;

    61 #endif // AMD64

    62 }

    64 #ifdef AMD64

    65 inline u8 Bytes::swap_u8(u8 x) {

    66 #ifdef SPARC_WORKS

    67   // workaround for SunStudio12 CR6615391

    68   __asm__ __volatile__ (

    69     "bswapq %0"

    70     :"=r" (x)        // output : register 0 => x

    71     :"0"  (x)        // input  : x => register 0

    72     :"0"             // clobbered register

    73   );

    74   return x;

    75 #else

    76   return bswap_64(x);

    77 #endif

    78 }

    79 #else

    80 // Helper function for swap_u8

    81 inline u8   Bytes::swap_u8_base(u4 x, u4 y) {

    82   return (((u8)swap_u4(x))<<32) | swap_u4(y);

    83 }

    85 inline u8 Bytes::swap_u8(u8 x) {

    86   return swap_u8_base(*(u4*)&x, *(((u4*)&x)+1));

    87 }

    88 #endif // !AMD64

    90 #endif // OS_CPU_LINUX_X86_VM_BYTES_LINUX_X86_INLINE_HPP

src/os_cpu/linux_x86/vm/bytes_linux_x86.inline.hpp@899ecf76b570

src/os_cpu/linux_x86/vm/bytes_linux_x86.inline.hpp

Mercurial > jdk8-mips64-public > hotspot / file revision

src/os_cpu/linux_x86/vm/bytes_linux_x86.inline.hpp@899ecf76b570

src/os_cpu/linux_x86/vm/bytes_linux_x86.inline.hpp