1 /**************************************************************************
2 *
3 * Copyright 2008 VMware, Inc.
4 * Copyright 2009-2010 Chia-I Wu <olvaffe@gmail.com>
5 * Copyright 2010-2011 LunarG, Inc.
6 * All Rights Reserved.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the
10 * "Software"), to deal in the Software without restriction, including
11 * without limitation the rights to use, copy, modify, merge, publish,
12 * distribute, sub license, and/or sell copies of the Software, and to
13 * permit persons to whom the Software is furnished to do so, subject to
14 * the following conditions:
15 *
16 * The above copyright notice and this permission notice (including the
17 * next paragraph) shall be included in all copies or substantial portions
18 * of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
26 * DEALINGS IN THE SOFTWARE.
27 *
28 **************************************************************************/
29
30
31 #include <stdlib.h>
32 #include <stdio.h>
33 #include <string.h>
34 #include <assert.h>
35 #include "c11/threads.h"
36
37 #include "eglglobals.h"
38 #include "egldisplay.h"
39 #include "egldriver.h"
40 #include "egllog.h"
41
42 #ifdef HAVE_MINCORE
43 #include <unistd.h>
44 #include <sys/mman.h>
45 #endif
46
47
48 static mtx_t _eglGlobalMutex = _MTX_INITIALIZER_NP;
49
50 struct _egl_global _eglGlobal =
51 {
52 .Mutex = &_eglGlobalMutex,
53 .DisplayList = NULL,
54 .NumAtExitCalls = 2,
55 .AtExitCalls = {
56 /* default AtExitCalls, called in reverse order */
57 _eglUnloadDrivers, /* always called last */
58 _eglFiniDisplay
59 },
60
61 .ClientOnlyExtensionString =
62 "EGL_EXT_client_extensions"
63 " EGL_EXT_platform_base"
64 " EGL_KHR_client_get_all_proc_addresses"
65 " EGL_KHR_debug",
66
67 .PlatformExtensionString =
68 #ifdef HAVE_WAYLAND_PLATFORM
69 " EGL_EXT_platform_wayland"
70 #endif
71 #ifdef HAVE_X11_PLATFORM
72 " EGL_EXT_platform_x11"
73 #endif
74 #ifdef HAVE_DRM_PLATFORM
75 " EGL_MESA_platform_gbm"
76 #endif
77 #ifdef HAVE_SURFACELESS_PLATFORM
78 " EGL_MESA_platform_surfaceless"
79 #endif
80 "",
81
82 .ClientExtensionString = NULL,
83
84 .debugCallback = NULL,
85 .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
86 };
87
88
89 static void
_eglAtExit(void)90 _eglAtExit(void)
91 {
92 EGLint i;
93 for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
94 _eglGlobal.AtExitCalls[i]();
95 }
96
97
98 void
_eglAddAtExitCall(void (* func)(void))99 _eglAddAtExitCall(void (*func)(void))
100 {
101 if (func) {
102 static EGLBoolean registered = EGL_FALSE;
103
104 mtx_lock(_eglGlobal.Mutex);
105
106 if (!registered) {
107 atexit(_eglAtExit);
108 registered = EGL_TRUE;
109 }
110
111 assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
112 _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
113
114 mtx_unlock(_eglGlobal.Mutex);
115 }
116 }
117
118 const char *
_eglGetClientExtensionString(void)119 _eglGetClientExtensionString(void)
120 {
121 const char *ret;
122
123 mtx_lock(_eglGlobal.Mutex);
124
125 if (_eglGlobal.ClientExtensionString == NULL) {
126 size_t clientLen = strlen(_eglGlobal.ClientOnlyExtensionString);
127 size_t platformLen = strlen(_eglGlobal.PlatformExtensionString);
128
129 _eglGlobal.ClientExtensionString = (char *) malloc(clientLen + platformLen + 1);
130 if (_eglGlobal.ClientExtensionString != NULL) {
131 char *ptr = _eglGlobal.ClientExtensionString;
132
133 memcpy(ptr, _eglGlobal.ClientOnlyExtensionString, clientLen);
134 ptr += clientLen;
135
136 if (platformLen > 0) {
137 // Note that if PlatformExtensionString is not empty, then it will
138 // already have a leading space.
139 assert(_eglGlobal.PlatformExtensionString[0] == ' ');
140 memcpy(ptr, _eglGlobal.PlatformExtensionString, platformLen);
141 ptr += platformLen;
142 }
143 *ptr = '\0';
144 }
145 }
146 ret = _eglGlobal.ClientExtensionString;
147
148 mtx_unlock(_eglGlobal.Mutex);
149 return ret;
150 }
151
152 EGLBoolean
_eglPointerIsDereferencable(void * p)153 _eglPointerIsDereferencable(void *p)
154 {
155 #ifdef HAVE_MINCORE
156 uintptr_t addr = (uintptr_t) p;
157 unsigned char valid = 0;
158 const long page_size = getpagesize();
159
160 if (p == NULL)
161 return EGL_FALSE;
162
163 /* align addr to page_size */
164 addr &= ~(page_size - 1);
165
166 if (mincore((void *) addr, page_size, &valid) < 0) {
167 _eglLog(_EGL_DEBUG, "mincore failed: %m");
168 return EGL_FALSE;
169 }
170
171 /* mincore() returns 0 on success, and -1 on failure. The last parameter
172 * is a vector of bytes with one entry for each page queried. mincore
173 * returns page residency information in the first bit of each byte in the
174 * vector.
175 *
176 * Residency doesn't actually matter when determining whether a pointer is
177 * dereferenceable, so the output vector can be ignored. What matters is
178 * whether mincore succeeds. See:
179 *
180 * http://man7.org/linux/man-pages/man2/mincore.2.html
181 */
182 return EGL_TRUE;
183 #else
184 return p != NULL;
185 #endif
186 }
187