src/mapi/mapi/entry_x86-64_tls.h

   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_execmem.h"
  31 #include "u_macros.h"
  32
  33 __asm__(".text");
  34
  35 __asm__("x86_64_current_tls:\n\t"
  36         "movq _glapi_tls_Dispatch@GOTTPOFF(%rip), %rax\n\t"
  37         "ret");
  38
  39 #define STUB_ASM_ENTRY(func)                             \
  40    ".globl " func "\n"                                   \
  41    ".type " func ", @function\n"                         \
  42    ".balign 32\n"                                        \
  43    func ":"
  44
  45 #define STUB_ASM_CODE(slot)                              \
  46    "movq _glapi_tls_Dispatch@GOTTPOFF(%rip), %rax\n\t"   \
  47    "movq %fs:(%rax), %r11\n\t"                           \
  48    "jmp *(8 * " slot ")(%r11)"
  49
  50 #define MAPI_TMP_STUB_ASM_GCC
  51 #include "mapi_tmp.h"
  52
  53 extern unsigned long
  54 x86_64_current_tls();
  55
  56 void
  57 entry_patch_public(void)
  58 {
  59 }
  60
  61 void
  62 entry_patch(mapi_func entry, int slot)
  63 {
  64    void *code = (void *) entry;
  65    *((unsigned int *) (code + 12)) = slot * sizeof(mapi_func);
  66 }
  67
  68 mapi_func
  69 entry_generate(int slot)
  70 {
  71    const char code_templ[16] = {
  72       /* movq %fs:0, %r11 */
  73       0x64, 0x4c, 0x8b, 0x1c, 0x25, 0x00, 0x00, 0x00, 0x00,
  74       /* jmp *0x1234(%r11) */
  75       0x41, 0xff, 0xa3, 0x34, 0x12, 0x00, 0x00,
  76    };
  77    unsigned long addr;
  78    void *code;
  79    mapi_func entry;
  80
  81    addr = x86_64_current_tls();
  82    if ((addr >> 32) != 0xffffffff)
  83       return NULL;
  84    addr &= 0xffffffff;
  85
  86    code = u_execmem_alloc(sizeof(code_templ));
  87    if (!code)
  88       return NULL;
  89
  90    memcpy(code, code_templ, sizeof(code_templ));
  91
  92    *((unsigned int *) (code + 5)) = addr;
  93    entry = (mapi_func) code;
  94    entry_patch(entry, slot);
  95
  96    return entry;
  97 }