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
77 void
entry_patch_public(void)78 entry_patch_public(void)
79 {
80 }
81
82 extern char
83 x86_64_entry_start[] HIDDEN;
84
85 mapi_func
entry_get_public(int slot)86 entry_get_public(int slot)
87 {
88 return (mapi_func) (x86_64_entry_start + slot * 32);
89 }
90
91 void
entry_patch(mapi_func entry,int slot)92 entry_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
102 mapi_func
entry_generate(int slot)103 entry_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