1/* 2 * Mesa 3-D graphics library 3 * Version: 7.9 4 * 5 * Copyright (C) 2010 LunarG Inc. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a 8 * copy of this software and associated documentation files (the "Software"), 9 * to deal in the Software without restriction, including without limitation 10 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 11 * and/or sell copies of the Software, and to permit persons to whom the 12 * Software is furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included 15 * in all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 23 * DEALINGS IN THE SOFTWARE. 24 * 25 * Authors: 26 * Chia-I Wu <olv@lunarg.com> 27 */ 28 29#include <string.h> 30#include "u_macros.h" 31 32#ifdef __linux__ 33__asm__(".section .note.ABI-tag, \"a\"\n\t" 34 ".p2align 2\n\t" 35 ".long 1f - 0f\n\t" /* name length */ 36 ".long 3f - 2f\n\t" /* data length */ 37 ".long 1\n\t" /* note length */ 38 "0: .asciz \"GNU\"\n\t" /* vendor name */ 39 "1: .p2align 2\n\t" 40 "2: .long 0\n\t" /* note data: the ABI tag */ 41 ".long 2,4,20\n\t" /* Minimum kernel version w/TLS */ 42 "3: .p2align 2\n\t"); /* pad out section */ 43#endif /* __linux__ */ 44 45__asm__(".text"); 46 47__asm__("x86_current_tls:\n\t" 48 "call 1f\n" 49 "1:\n\t" 50 "popl %eax\n\t" 51 "addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %eax\n\t" 52 "movl " ENTRY_CURRENT_TABLE "@GOTNTPOFF(%eax), %eax\n\t" 53 "ret"); 54 55#ifndef GLX_X86_READONLY_TEXT 56__asm__(".section wtext, \"awx\", @progbits"); 57#endif /* GLX_X86_READONLY_TEXT */ 58 59__asm__(".balign 16\n" 60 "x86_entry_start:"); 61 62#define STUB_ASM_ENTRY(func) \ 63 ".globl " func "\n" \ 64 ".type " func ", @function\n" \ 65 ".balign 16\n" \ 66 func ":" 67 68#define STUB_ASM_CODE(slot) \ 69 "call x86_current_tls\n\t" \ 70 "movl %gs:(%eax), %eax\n\t" \ 71 "jmp *(4 * " slot ")(%eax)" 72 73#define MAPI_TMP_STUB_ASM_GCC 74#include "mapi_tmp.h" 75 76#ifndef GLX_X86_READONLY_TEXT 77__asm__(".balign 16\n" 78 "x86_entry_end:"); 79__asm__(".text"); 80#endif /* GLX_X86_READONLY_TEXT */ 81 82#ifndef MAPI_MODE_BRIDGE 83 84#include "u_execmem.h" 85 86extern unsigned long 87x86_current_tls(); 88 89static char x86_entry_start[]; 90static char x86_entry_end[]; 91 92void 93entry_patch_public(void) 94{ 95#ifndef GLX_X86_READONLY_TEXT 96 char patch[8] = { 97 0x65, 0xa1, 0x00, 0x00, 0x00, 0x00, /* movl %gs:0x0, %eax */ 98 0x90, 0x90 /* nop's */ 99 }; 100 char *entry; 101 102 *((unsigned long *) (patch + 2)) = x86_current_tls(); 103 104 for (entry = x86_entry_start; entry < x86_entry_end; entry += 16) 105 memcpy(entry, patch, sizeof(patch)); 106#endif 107} 108 109mapi_func 110entry_get_public(int slot) 111{ 112 return (mapi_func) (x86_entry_start + slot * 16); 113} 114 115void 116entry_patch(mapi_func entry, int slot) 117{ 118 char *code = (char *) entry; 119 *((unsigned long *) (code + 8)) = slot * sizeof(mapi_func); 120} 121 122mapi_func 123entry_generate(int slot) 124{ 125 const char code_templ[16] = { 126 0x65, 0xa1, 0x00, 0x00, 0x00, 0x00, /* movl %gs:0x0, %eax */ 127 0xff, 0xa0, 0x34, 0x12, 0x00, 0x00, /* jmp *0x1234(%eax) */ 128 0x90, 0x90, 0x90, 0x90 /* nop's */ 129 }; 130 void *code; 131 mapi_func entry; 132 133 code = u_execmem_alloc(sizeof(code_templ)); 134 if (!code) 135 return NULL; 136 137 memcpy(code, code_templ, sizeof(code_templ)); 138 139 *((unsigned long *) (code + 2)) = x86_current_tls(); 140 entry = (mapi_func) code; 141 entry_patch(entry, slot); 142 143 return entry; 144} 145 146#endif /* MAPI_MODE_BRIDGE */ 147