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 <string.h>
30#include "u_macros.h"
31
32#ifdef __linux__
33__asm__(".section .note.ABI-tag, \"a\"\n\t"
34        ".p2align 2\n\t"
35        ".long 1f - 0f\n\t"      /* name length */
36        ".long 3f - 2f\n\t"      /* data length */
37        ".long 1\n\t"            /* note length */
38        "0: .asciz \"GNU\"\n\t"  /* vendor name */
39        "1: .p2align 2\n\t"
40        "2: .long 0\n\t"         /* note data: the ABI tag */
41        ".long 2,4,20\n\t"       /* Minimum kernel version w/TLS */
42        "3: .p2align 2\n\t");    /* pad out section */
43#endif /* __linux__ */
44
45__asm__(".text");
46
47__asm__("x86_current_tls:\n\t"
48	"call 1f\n"
49        "1:\n\t"
50        "popl %eax\n\t"
51	"addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %eax\n\t"
52	"movl " ENTRY_CURRENT_TABLE "@GOTNTPOFF(%eax), %eax\n\t"
53	"ret");
54
55#ifndef GLX_X86_READONLY_TEXT
56__asm__(".section wtext, \"awx\", @progbits");
57#endif /* GLX_X86_READONLY_TEXT */
58
59__asm__(".balign 16\n"
60        "x86_entry_start:");
61
62#define STUB_ASM_ENTRY(func)     \
63   ".globl " func "\n"           \
64   ".type " func ", @function\n" \
65   ".balign 16\n"                \
66   func ":"
67
68#define STUB_ASM_CODE(slot)      \
69   "call x86_current_tls\n\t"    \
70   "movl %gs:(%eax), %eax\n\t"   \
71   "jmp *(4 * " slot ")(%eax)"
72
73#define MAPI_TMP_STUB_ASM_GCC
74#include "mapi_tmp.h"
75
76#ifndef GLX_X86_READONLY_TEXT
77__asm__(".balign 16\n"
78        "x86_entry_end:");
79__asm__(".text");
80#endif /* GLX_X86_READONLY_TEXT */
81
82#ifndef MAPI_MODE_BRIDGE
83
84#include "u_execmem.h"
85
86extern unsigned long
87x86_current_tls();
88
89static char x86_entry_start[];
90static char x86_entry_end[];
91
92void
93entry_patch_public(void)
94{
95#ifndef GLX_X86_READONLY_TEXT
96   char patch[8] = {
97      0x65, 0xa1, 0x00, 0x00, 0x00, 0x00, /* movl %gs:0x0, %eax */
98      0x90, 0x90                          /* nop's */
99   };
100   char *entry;
101
102   *((unsigned long *) (patch + 2)) = x86_current_tls();
103
104   for (entry = x86_entry_start; entry < x86_entry_end; entry += 16)
105      memcpy(entry, patch, sizeof(patch));
106#endif
107}
108
109mapi_func
110entry_get_public(int slot)
111{
112   return (mapi_func) (x86_entry_start + slot * 16);
113}
114
115void
116entry_patch(mapi_func entry, int slot)
117{
118   char *code = (char *) entry;
119   *((unsigned long *) (code + 8)) = slot * sizeof(mapi_func);
120}
121
122mapi_func
123entry_generate(int slot)
124{
125   const char code_templ[16] = {
126      0x65, 0xa1, 0x00, 0x00, 0x00, 0x00, /* movl %gs:0x0, %eax */
127      0xff, 0xa0, 0x34, 0x12, 0x00, 0x00, /* jmp *0x1234(%eax) */
128      0x90, 0x90, 0x90, 0x90              /* nop's */
129   };
130   void *code;
131   mapi_func entry;
132
133   code = u_execmem_alloc(sizeof(code_templ));
134   if (!code)
135      return NULL;
136
137   memcpy(code, code_templ, sizeof(code_templ));
138
139   *((unsigned long *) (code + 2)) = x86_current_tls();
140   entry = (mapi_func) code;
141   entry_patch(entry, slot);
142
143   return entry;
144}
145
146#endif /* MAPI_MODE_BRIDGE */
147