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