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 64\n"
42        "x86_64_entry_start:");
43
44#define STUB_ASM_ENTRY(func)                             \
45   ".globl " func "\n"                                   \
46   ".type " func ", @function\n"                         \
47   ".balign 64\n"                                        \
48   func ":"
49
50#ifndef __ILP32__
51
52#if defined(__NetBSD__)
53#define STUB_ASM_CODE(slot)                              \
54   "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"  \
55   "movq %fs:(%rax), %r11\n\t"                           \
56   "testq %r11, %r11\n\t"                                \
57   "je 1f\n\t"                                           \
58   "jmp *(8 * " slot ")(%r11)\n\t"                       \
59   "1:\n\t"                                              \
60   "callq " ENTRY_CURRENT_TABLE_GET "@PLT\n\t"           \
61   "jmp *(8 * " slot ")(%rax)"
62#else
63#define STUB_ASM_CODE(slot)                              \
64   ENDBR                                                 \
65   "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"  \
66   "movq %fs:(%rax), %r11\n\t"                           \
67   "jmp *(8 * " slot ")(%r11)"
68#endif
69
70#else
71
72#define STUB_ASM_CODE(slot)                              \
73   ENDBR                                                 \
74   "movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%rip), %rax\n\t"  \
75   "movl %fs:(%rax), %r11d\n\t"                          \
76   "movl 4*" slot "(%r11d), %r11d\n\t"                   \
77   "jmp *%r11"
78
79#endif
80
81#define MAPI_TMP_STUB_ASM_GCC
82#include "mapi_tmp.h"
83
84#ifndef MAPI_MODE_BRIDGE
85
86#include <string.h>
87#include "u_execmem.h"
88
89void
90entry_patch_public(void)
91{
92}
93
94extern char
95x86_64_entry_start[] HIDDEN;
96
97mapi_func
98entry_get_public(int slot)
99{
100   return (mapi_func) (x86_64_entry_start + slot * 64);
101}
102
103void
104entry_patch(mapi_func entry, int slot)
105{
106   char *code = (char *) entry;
107   int offset = 12;
108#ifdef __ILP32__
109   offset = 13;
110#endif
111   *((unsigned int *) (code + offset)) = slot * sizeof(mapi_func);
112}
113
114mapi_func
115entry_generate(int slot)
116{
117   const char code_templ[] = {
118#ifndef __ILP32__
119      /* movq %fs:0, %r11 */
120      0x64, 0x4c, 0x8b, 0x1c, 0x25, 0x00, 0x00, 0x00, 0x00,
121      /* jmp *0x1234(%r11) */
122      0x41, 0xff, 0xa3, 0x34, 0x12, 0x00, 0x00,
123#else
124      /* movl %fs:0, %r11d */
125      0x64, 0x44, 0x8b, 0x1c, 0x25, 0x00, 0x00, 0x00, 0x00,
126      /* movl 0x1234(%r11d), %r11d */
127      0x67, 0x45, 0x8b, 0x9b, 0x34, 0x12, 0x00, 0x00,
128      /* jmp *%r11 */
129      0x41, 0xff, 0xe3,
130#endif
131   };
132   unsigned long long addr;
133   char *code;
134   mapi_func entry;
135
136   __asm__("movq " ENTRY_CURRENT_TABLE "@GOTTPOFF(%%rip), %0"
137           : "=r" (addr));
138   if ((addr >> 32) != 0xffffffff)
139      return NULL;
140   addr &= 0xffffffff;
141
142   code = u_execmem_alloc(sizeof(code_templ));
143   if (!code)
144      return NULL;
145
146   memcpy(code, code_templ, sizeof(code_templ));
147
148   *((unsigned int *) (code + 5)) = addr;
149   entry = (mapi_func) code;
150   entry_patch(entry, slot);
151
152   return entry;
153}
154
155#endif /* MAPI_MODE_BRIDGE */
156