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src/os_cpu/linux_x86/vm/bytes_linux_x86.inline.hpp@899ecf76b570 (annotated)
src/os_cpu/linux_x86/vm/bytes_linux_x86.inline.hpp
Wed, 25 Sep 2013 13:58:13 +0200
- author
- dsimms
- date
- Wed, 25 Sep 2013 13:58:13 +0200
- changeset 5781
- 899ecf76b570
- parent 2314
- f95d63e2154a
- 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
| duke@435 | 1 | /* |
| stefank@2314 | 2 | * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved. |
| duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| duke@435 | 4 | * |
| duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
| duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
| duke@435 | 7 | * published by the Free Software Foundation. |
| duke@435 | 8 | * |
| duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| duke@435 | 13 | * accompanied this code). |
| duke@435 | 14 | * |
| duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
| duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| duke@435 | 18 | * |
| trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
| trims@1907 | 21 | * questions. |
| duke@435 | 22 | * |
| duke@435 | 23 | */ |
| duke@435 | 24 | |
| stefank@2314 | 25 | #ifndef OS_CPU_LINUX_X86_VM_BYTES_LINUX_X86_INLINE_HPP |
| stefank@2314 | 26 | #define OS_CPU_LINUX_X86_VM_BYTES_LINUX_X86_INLINE_HPP |
| stefank@2314 | 27 | |
| duke@435 | 28 | #include <byteswap.h> |
| duke@435 | 29 | |
| duke@435 | 30 | // Efficient swapping of data bytes from Java byte |
| duke@435 | 31 | // ordering to native byte ordering and vice versa. |
| duke@435 | 32 | inline u2 Bytes::swap_u2(u2 x) { |
| duke@435 | 33 | #ifdef AMD64 |
| duke@435 | 34 | return bswap_16(x); |
| duke@435 | 35 | #else |
| duke@435 | 36 | u2 ret; |
| duke@435 | 37 | __asm__ __volatile__ ( |
| duke@435 | 38 | "movw %0, %%ax;" |
| duke@435 | 39 | "xchg %%al, %%ah;" |
| duke@435 | 40 | "movw %%ax, %0" |
| duke@435 | 41 | :"=r" (ret) // output : register 0 => ret |
| duke@435 | 42 | :"0" (x) // input : x => register 0 |
| duke@435 | 43 | :"ax", "0" // clobbered registers |
| duke@435 | 44 | ); |
| duke@435 | 45 | return ret; |
| duke@435 | 46 | #endif // AMD64 |
| duke@435 | 47 | } |
| duke@435 | 48 | |
| duke@435 | 49 | inline u4 Bytes::swap_u4(u4 x) { |
| duke@435 | 50 | #ifdef AMD64 |
| duke@435 | 51 | return bswap_32(x); |
| duke@435 | 52 | #else |
| duke@435 | 53 | u4 ret; |
| duke@435 | 54 | __asm__ __volatile__ ( |
| duke@435 | 55 | "bswap %0" |
| duke@435 | 56 | :"=r" (ret) // output : register 0 => ret |
| duke@435 | 57 | :"0" (x) // input : x => register 0 |
| duke@435 | 58 | :"0" // clobbered register |
| duke@435 | 59 | ); |
| duke@435 | 60 | return ret; |
| duke@435 | 61 | #endif // AMD64 |
| duke@435 | 62 | } |
| duke@435 | 63 | |
| duke@435 | 64 | #ifdef AMD64 |
| duke@435 | 65 | inline u8 Bytes::swap_u8(u8 x) { |
| dcubed@485 | 66 | #ifdef SPARC_WORKS |
| dcubed@485 | 67 | // workaround for SunStudio12 CR6615391 |
| dcubed@485 | 68 | __asm__ __volatile__ ( |
| dcubed@485 | 69 | "bswapq %0" |
| dcubed@485 | 70 | :"=r" (x) // output : register 0 => x |
| dcubed@485 | 71 | :"0" (x) // input : x => register 0 |
| dcubed@485 | 72 | :"0" // clobbered register |
| dcubed@485 | 73 | ); |
| dcubed@485 | 74 | return x; |
| dcubed@485 | 75 | #else |
| duke@435 | 76 | return bswap_64(x); |
| dcubed@485 | 77 | #endif |
| duke@435 | 78 | } |
| duke@435 | 79 | #else |
| duke@435 | 80 | // Helper function for swap_u8 |
| duke@435 | 81 | inline u8 Bytes::swap_u8_base(u4 x, u4 y) { |
| duke@435 | 82 | return (((u8)swap_u4(x))<<32) | swap_u4(y); |
| duke@435 | 83 | } |
| duke@435 | 84 | |
| duke@435 | 85 | inline u8 Bytes::swap_u8(u8 x) { |
| duke@435 | 86 | return swap_u8_base(*(u4*)&x, *(((u4*)&x)+1)); |
| duke@435 | 87 | } |
| duke@435 | 88 | #endif // !AMD64 |
| stefank@2314 | 89 | |
| stefank@2314 | 90 | #endif // OS_CPU_LINUX_X86_VM_BYTES_LINUX_X86_INLINE_HPP |
