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 "egldevice.h"
39 #include "egldisplay.h"
40
41 #include "util/macros.h"
42
43 #ifdef HAVE_MINCORE
44 #include <unistd.h>
45 #include <sys/mman.h>
46 #endif
47
48
49 static mtx_t _eglGlobalMutex = _MTX_INITIALIZER_NP;
50
51 struct _egl_global _eglGlobal =
52 {
53 .Mutex = &_eglGlobalMutex,
54 .DisplayList = NULL,
55 .DeviceList = &_eglSoftwareDevice,
56 .NumAtExitCalls = 2,
57 .AtExitCalls = {
58 /* default AtExitCalls, called in reverse order */
59 _eglFiniDevice, /* always called last */
60 _eglFiniDisplay,
61 },
62
63 #if USE_LIBGLVND
64 .ClientOnlyExtensionString =
65 #else
66 .ClientExtensionString =
67 #endif
68 "EGL_EXT_client_extensions"
69 " EGL_EXT_device_base"
70 " EGL_EXT_device_enumeration"
71 " EGL_EXT_device_query"
72 " EGL_EXT_platform_base"
73 " EGL_KHR_client_get_all_proc_addresses"
74 " EGL_KHR_debug"
75
76 #if USE_LIBGLVND
77 ,
78 .PlatformExtensionString =
79 #else
80 " "
81 #endif
82
83 "EGL_EXT_platform_device"
84 #ifdef HAVE_WAYLAND_PLATFORM
85 " EGL_EXT_platform_wayland"
86 " EGL_KHR_platform_wayland"
87 #endif
88 #ifdef HAVE_X11_PLATFORM
89 " EGL_EXT_platform_x11"
90 " EGL_KHR_platform_x11"
91 #endif
92 #ifdef HAVE_DRM_PLATFORM
93 " EGL_MESA_platform_gbm"
94 " EGL_KHR_platform_gbm"
95 #endif
96 " EGL_MESA_platform_surfaceless"
97 "",
98
99 .debugCallback = NULL,
100 .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
101 };
102
103
104 static void
_eglAtExit(void)105 _eglAtExit(void)
106 {
107 EGLint i;
108 for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
109 _eglGlobal.AtExitCalls[i]();
110 }
111
112
113 void
_eglAddAtExitCall(void (* func)(void))114 _eglAddAtExitCall(void (*func)(void))
115 {
116 if (func) {
117 static EGLBoolean registered = EGL_FALSE;
118
119 mtx_lock(_eglGlobal.Mutex);
120
121 if (!registered) {
122 atexit(_eglAtExit);
123 registered = EGL_TRUE;
124 }
125
126 assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
127 _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
128
129 mtx_unlock(_eglGlobal.Mutex);
130 }
131 }
132
133 EGLBoolean
_eglPointerIsDereferencable(void * p)134 _eglPointerIsDereferencable(void *p)
135 {
136 uintptr_t addr = (uintptr_t) p;
137 const long page_size = getpagesize();
138 #ifdef HAVE_MINCORE
139 unsigned char valid = 0;
140
141 if (p == NULL)
142 return EGL_FALSE;
143
144 /* align addr to page_size */
145 addr &= ~(page_size - 1);
146
147 if (mincore((void *) addr, page_size, &valid) < 0) {
148 return EGL_FALSE;
149 }
150
151 /* mincore() returns 0 on success, and -1 on failure. The last parameter
152 * is a vector of bytes with one entry for each page queried. mincore
153 * returns page residency information in the first bit of each byte in the
154 * vector.
155 *
156 * Residency doesn't actually matter when determining whether a pointer is
157 * dereferenceable, so the output vector can be ignored. What matters is
158 * whether mincore succeeds. See:
159 *
160 * http://man7.org/linux/man-pages/man2/mincore.2.html
161 */
162 return EGL_TRUE;
163 #else
164 // Without mincore(), we just assume that the first page is unmapped.
165 return addr >= page_size;
166 #endif
167 }
168