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 "u_macros.h"
  30
  31 #ifdef __linux__
  32 __asm__(".section .note.ABI-tag, \"a\"\n\t"
  33         ".p2align 2\n\t"
  34         ".long 1f - 0f\n\t"      /* name length */
  35         ".long 3f - 2f\n\t"      /* data length */
  36         ".long 1\n\t"            /* note length */
  37         "0: .asciz \"GNU\"\n\t"  /* vendor name */
  38         "1: .p2align 2\n\t"
  39         "2: .long 0\n\t"         /* note data: the ABI tag */
  40         ".long 2,4,20\n\t"       /* Minimum kernel version w/TLS */
  41         "3: .p2align 2\n\t");    /* pad out section */
  42 #endif /* __linux__ */
  43
  44 __asm__(".text\n"
  45         ".balign 32\n"
  46         "x86_64_entry_start:");
  47
  48 #define STUB_ASM_ENTRY(func)                             \
  49    ".globl " func "\n"                                   \
  50    ".type " func ", @function\n"                         \
  51    ".balign 32\n"                                        \
  52    func ":"
  53
  54 #define STUB_ASM_CODE(slot)                              \
  55    "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"  \
  56    "movq %fs:(%rax), %r11\n\t"                           \
  57    "jmp *(8 * " slot ")(%r11)"
  58
  59 #define MAPI_TMP_STUB_ASM_GCC
  60 #include "mapi_tmp.h"
  61
  62 #ifndef MAPI_MODE_BRIDGE
  63
  64 __asm__("x86_64_current_tls:\n\t"
  65         "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"
  66         "ret");
  67
  68 extern unsigned long
  69 x86_64_current_tls();
  70
  71 #include <string.h>
  72 #include "u_execmem.h"
  73
  74 void
  75 entry_patch_public(void)
  76 {
  77 }
  78
  79 mapi_func
  80 entry_get_public(int slot)
  81 {
  82    extern char x86_64_entry_start[];
  83    return (mapi_func) (x86_64_entry_start + slot * 32);
  84 }
  85
  86 void
  87 entry_patch(mapi_func entry, int slot)
  88 {
  89    char *code = (char *) entry;
  90    *((unsigned int *) (code + 12)) = slot * sizeof(mapi_func);
  91 }
  92
  93 mapi_func
  94 entry_generate(int slot)
  95 {
  96    const char code_templ[16] = {
  97       /* movq %fs:0, %r11 */
  98       0x64, 0x4c, 0x8b, 0x1c, 0x25, 0x00, 0x00, 0x00, 0x00,
  99       /* jmp *0x1234(%r11) */
 100       0x41, 0xff, 0xa3, 0x34, 0x12, 0x00, 0x00,
 101    };
 102    unsigned long addr;
 103    void *code;
 104    mapi_func entry;
 105
 106    addr = x86_64_current_tls();
 107    if ((addr >> 32) != 0xffffffff)
 108       return NULL;
 109    addr &= 0xffffffff;
 110
 111    code = u_execmem_alloc(sizeof(code_templ));
 112    if (!code)
 113       return NULL;
 114
 115    memcpy(code, code_templ, sizeof(code_templ));
 116
 117    *((unsigned int *) (code + 5)) = addr;
 118    entry = (mapi_func) code;
 119    entry_patch(entry, slot);
 120
 121    return entry;
 122 }
 123
 124 #endif /* MAPI_MODE_BRIDGE */