src/mapi/entry_x86-64_tls.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
  29 __asm__(".text\n"
  30         ".balign 32\n"
  31         "x86_64_entry_start:");
  32
  33 #define STUB_ASM_ENTRY(func)                             \
  34    ".globl " func "\n"                                   \
  35    ".type " func ", @function\n"                         \
  36    ".balign 32\n"                                        \
  37    func ":"
  38
  39 #define STUB_ASM_CODE(slot)                              \
  40    "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"  \
  41    "movq %fs:(%rax), %r11\n\t"                           \
  42    "jmp *(8 * " slot ")(%r11)"
  43
  44 #define MAPI_TMP_STUB_ASM_GCC
  45 #include "mapi_tmp.h"
  46
  47 #ifndef MAPI_MODE_BRIDGE
  48
  49 __asm__("x86_64_current_tls:\n\t"
  50         "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"
  51         "ret");
  52
  53 extern unsigned long
  54 x86_64_current_tls();
  55
  56 #include <string.h>
  57 #include "u_execmem.h"
  58
  59 void
  60 entry_patch_public(void)
  61 {
  62 }
  63
  64 static char
  65 x86_64_entry_start[];
  66
  67 mapi_func
  68 entry_get_public(int slot)
  69 {
  70    return (mapi_func) (x86_64_entry_start + slot * 32);
  71 }
  72
  73 void
  74 entry_patch(mapi_func entry, int slot)
  75 {
  76    char *code = (char *) entry;
  77    *((unsigned int *) (code + 12)) = slot * sizeof(mapi_func);
  78 }
  79
  80 mapi_func
  81 entry_generate(int slot)
  82 {
  83    const char code_templ[16] = {
  84       /* movq %fs:0, %r11 */
  85       0x64, 0x4c, 0x8b, 0x1c, 0x25, 0x00, 0x00, 0x00, 0x00,
  86       /* jmp *0x1234(%r11) */
  87       0x41, 0xff, 0xa3, 0x34, 0x12, 0x00, 0x00,
  88    };
  89    unsigned long addr;
  90    char *code;
  91    mapi_func entry;
  92
  93    addr = x86_64_current_tls();
  94    if ((addr >> 32) != 0xffffffff)
  95       return NULL;
  96    addr &= 0xffffffff;
  97
  98    code = u_execmem_alloc(sizeof(code_templ));
  99    if (!code)
 100       return NULL;
 101
 102    memcpy(code, code_templ, sizeof(code_templ));
 103
 104    *((unsigned int *) (code + 5)) = addr;
 105    entry = (mapi_func) code;
 106    entry_patch(entry, slot);
 107
 108    return entry;
 109 }
 110
 111 #endif /* MAPI_MODE_BRIDGE */