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 "endbr64\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__asm__(".text\n"
41        ".balign 32\n"
42        "x86_64_entry_start:");
43
44#define STUB_ASM_ENTRY(func)                             \
45   ".globl " func "\n"                                   \
46   ".type " func ", @function\n"                         \
47   ".balign 32\n"                                        \
48   func ":"
49
50#ifndef __ILP32__
51
52#define STUB_ASM_CODE(slot)                              \
53   ENDBR                                                 \
54   "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"  \
55   "movq %fs:(%rax), %r11\n\t"                           \
56   "jmp *(8 * " slot ")(%r11)"
57
58#else
59
60#define STUB_ASM_CODE(slot)                              \
61   ENDBR                                                 \
62   "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"  \
63   "movl %fs:(%rax), %r11d\n\t"                          \
64   "movl 4*" slot "(%r11d), %r11d\n\t"                   \
65   "jmp *%r11"
66
67#endif
68
69#define MAPI_TMP_STUB_ASM_GCC
70#include "mapi_tmp.h"
71
72#ifndef MAPI_MODE_BRIDGE
73
74#include <string.h>
75#include "u_execmem.h"
76
77void
78entry_patch_public(void)
79{
80}
81
82extern char
83x86_64_entry_start[] HIDDEN;
84
85mapi_func
86entry_get_public(int slot)
87{
88   return (mapi_func) (x86_64_entry_start + slot * 32);
89}
90
91void
92entry_patch(mapi_func entry, int slot)
93{
94   char *code = (char *) entry;
95   int offset = 12;
96#ifdef __ILP32__
97   offset = 13;
98#endif
99   *((unsigned int *) (code + offset)) = slot * sizeof(mapi_func);
100}
101
102mapi_func
103entry_generate(int slot)
104{
105   const char code_templ[] = {
106#ifndef __ILP32__
107      /* movq %fs:0, %r11 */
108      0x64, 0x4c, 0x8b, 0x1c, 0x25, 0x00, 0x00, 0x00, 0x00,
109      /* jmp *0x1234(%r11) */
110      0x41, 0xff, 0xa3, 0x34, 0x12, 0x00, 0x00,
111#else
112      /* movl %fs:0, %r11d */
113      0x64, 0x44, 0x8b, 0x1c, 0x25, 0x00, 0x00, 0x00, 0x00,
114      /* movl 0x1234(%r11d), %r11d */
115      0x67, 0x45, 0x8b, 0x9b, 0x34, 0x12, 0x00, 0x00,
116      /* jmp *%r11 */
117      0x41, 0xff, 0xe3,
118#endif
119   };
120   unsigned long long addr;
121   char *code;
122   mapi_func entry;
123
124   __asm__("movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%%rip), %0"
125           : "=r" (addr));
126   if ((addr >> 32) != 0xffffffff)
127      return NULL;
128   addr &= 0xffffffff;
129
130   code = u_execmem_alloc(sizeof(code_templ));
131   if (!code)
132      return NULL;
133
134   memcpy(code, code_templ, sizeof(code_templ));
135
136   *((unsigned int *) (code + 5)) = addr;
137   entry = (mapi_func) code;
138   entry_patch(entry, slot);
139
140   return entry;
141}
142
143#endif /* MAPI_MODE_BRIDGE */
144