src/mapi/entry_x86_tsd.h

   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@lunarg.com>
  26  */
  27
  28 #ifdef __CET__
  29 #define ENDBR "endbr32\n\t"
  30 #else
  31 #define ENDBR
  32 #endif
  33
  34 #ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
  35 #define HIDDEN __attribute__((visibility("hidden")))
  36 #else
  37 #define HIDDEN
  38 #endif
  39
  40 #define X86_ENTRY_SIZE 64
  41
  42 __asm__(".text\n");
  43
  44 __asm__("x86_got:\n\t"
  45         "call 1f\n"
  46         "1:\n\t"
  47         "popl %eax\n\t"
  48         "addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %eax\n\t"
  49         "ret");
  50
  51 __asm__(".balign 32\n"
  52         "x86_entry_start:");
  53
  54 #define STUB_ASM_ENTRY(func)        \
  55    ".globl " func "\n"              \
  56    ".type " func ", @function\n"    \
  57    ".balign 32\n"                   \
  58    func ":"
  59
  60 #define LOC_BEGIN_SET_ECX
  61 #define LOC_END_SET_ECX
  62 #define LOC_END_JMP
  63
  64 #define STUB_ASM_CODE(slot)         \
  65    ENDBR                            \
  66    LOC_BEGIN_SET_ECX                \
  67    "call 1f\n\t"                    \
  68    "1:\n\t"                         \
  69    "popl %ecx\n\t"                  \
  70    "addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %ecx\n\t" \
  71    LOC_END_SET_ECX                                \
  72    "movl " ENTRY_CURRENT_TABLE "@GOT(%ecx), %eax\n\t" \
  73    "mov (%eax), %eax\n\t"           \
  74    "testl %eax, %eax\n\t"           \
  75    "jne 1f\n\t"                     \
  76    "push %ebx\n\t"                  \
  77    "movl %ecx, %ebx\n\t"            \
  78    "call " ENTRY_CURRENT_TABLE_GET "@PLT\n\t" \
  79    "popl %ebx\n\t"                  \
  80    "1:\n\t"                         \
  81    "jmp *(4 * " slot ")(%eax)\n\t" \
  82    LOC_END_JMP
  83
  84 #define MAPI_TMP_STUB_ASM_GCC
  85 #include "mapi_tmp.h"
  86
  87 #ifndef MAPI_MODE_BRIDGE
  88
  89 __asm__(".balign 32\n"
  90         "x86_entry_end:");
  91
  92 #undef LOC_BEGIN_SET_ECX
  93 #undef LOC_END_SET_ECX
  94 #undef LOC_END_JMP
  95 #define LOC_BEGIN_SET_ECX "jmp set_ecx\n\t"
  96 #define LOC_END_SET_ECX "set_ecx:movl $0x12345678, %ecx\n\tloc_end_set_ecx:\n\t"
  97 #define LOC_END_JMP "loc_end_jmp:"
  98
  99 /* Any number big enough works. This is to make sure the final
 100  * jmp is a long jmp */
 101 __asm__(STUB_ASM_CODE("10000"));
 102
 103 extern const char loc_end_set_ecx[] HIDDEN;
 104 extern const char loc_end_jmp[] HIDDEN;
 105
 106 #include <string.h>
 107 #include "u_execmem.h"
 108
 109 extern unsigned long
 110 x86_got();
 111
 112 extern const char x86_entry_start[] HIDDEN;
 113 extern const char x86_entry_end[] HIDDEN;
 114
 115 void
 116 entry_patch_public(void)
 117 {
 118 }
 119
 120 mapi_func
 121 entry_get_public(int slot)
 122 {
 123    return (mapi_func) (x86_entry_start + slot * X86_ENTRY_SIZE);
 124 }
 125
 126 void
 127 entry_patch(mapi_func entry, int slot)
 128 {
 129    char *code = (char *) entry;
 130    int offset = loc_end_jmp - x86_entry_end - sizeof(unsigned long);
 131    *((unsigned long *) (code + offset)) = slot * sizeof(mapi_func);
 132 }
 133
 134 mapi_func
 135 entry_generate(int slot)
 136 {
 137    const char *code_templ = x86_entry_end;
 138    char *code;
 139    mapi_func entry;
 140
 141    code = u_execmem_alloc(X86_ENTRY_SIZE);
 142    if (!code)
 143       return NULL;
 144
 145    memcpy(code, code_templ, X86_ENTRY_SIZE);
 146    entry = (mapi_func) code;
 147    int ecx_value_off = loc_end_set_ecx - x86_entry_end - sizeof(unsigned long);
 148    *((unsigned long *) (code + ecx_value_off)) = x86_got();
 149
 150    entry_patch(entry, slot);
 151
 152    return entry;
 153 }
 154
 155 #endif /* MAPI_MODE_BRIDGE */