egl: Fix _eglPointerIsDereferencable w/o mincore()

[mesa.git] / src / egl / main / eglglobals.c

diff --git a/src/egl/main/eglglobals.c b/src/egl/main/eglglobals.c
index 129bf29f1e95bb65d3d1d94403dcc9a11fac9ccc..5760edc3d3c11719d9a14309321044884b775c74 100644 (file)
--- a/src/egl/main/eglglobals.c
+++ b/src/egl/main/eglglobals.c
@@ -29,44 +29,69 @@
 
 
 #include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
 #include <assert.h>
 #include "c11/threads.h"
 
 #include "eglglobals.h"
+#include "egldevice.h"
 #include "egldisplay.h"
 #include "egldriver.h"
+#include "egllog.h"
+
+#include "util/macros.h"
+
+#ifdef HAVE_MINCORE
+#include <unistd.h>
+#include <sys/mman.h>
+#endif
 
 
 static mtx_t _eglGlobalMutex = _MTX_INITIALIZER_NP;
 
 struct _egl_global _eglGlobal =
 {
-   &_eglGlobalMutex,       /* Mutex */
-   NULL,                   /* DisplayList */
-   2,                      /* NumAtExitCalls */
-   {
+   .Mutex = &_eglGlobalMutex,
+   .DisplayList = NULL,
+   .DeviceList = &_eglSoftwareDevice,
+   .NumAtExitCalls = 3,
+   .AtExitCalls = {
       /* default AtExitCalls, called in reverse order */
-      _eglUnloadDrivers, /* always called last */
-      _eglFiniDisplay
-   },
-
-   /* ClientExtensions */
-   {
-      true, /* EGL_EXT_client_extensions */
-      true, /* EGL_EXT_platform_base */
-      true, /* EGL_EXT_platform_x11 */
-      true, /* EGL_EXT_platform_wayland */
-      true, /* EGL_MESA_platform_gbm */
-      true, /* EGL_KHR_client_get_all_proc_addresses */
+      _eglFiniDevice, /* always called last */
+      _eglUnloadDrivers,
+      _eglFiniDisplay,
    },
 
-   /* ClientExtensionsString */
+   .ClientOnlyExtensionString =
    "EGL_EXT_client_extensions"
+   " EGL_EXT_device_base"
+   " EGL_EXT_device_enumeration"
+   " EGL_EXT_device_query"
    " EGL_EXT_platform_base"
-   " EGL_EXT_platform_x11"
+   " EGL_KHR_client_get_all_proc_addresses"
+   " EGL_KHR_debug",
+
+   .PlatformExtensionString =
+#ifdef HAVE_WAYLAND_PLATFORM
    " EGL_EXT_platform_wayland"
+#endif
+#ifdef HAVE_X11_PLATFORM
+   " EGL_EXT_platform_x11"
+#endif
+#ifdef HAVE_DRM_PLATFORM
    " EGL_MESA_platform_gbm"
-   " EGL_KHR_client_get_all_proc_addresses"
+#endif
+#ifdef HAVE_SURFACELESS_PLATFORM
+   " EGL_MESA_platform_surfaceless"
+#endif
+   " EGL_EXT_platform_device"
+   "",
+
+   .ClientExtensionString = NULL,
+
+   .debugCallback = NULL,
+   .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
 };
 
 
@@ -98,3 +123,74 @@ _eglAddAtExitCall(void (*func)(void))
       mtx_unlock(_eglGlobal.Mutex);
    }
 }
+
+const char *
+_eglGetClientExtensionString(void)
+{
+   const char *ret;
+
+   mtx_lock(_eglGlobal.Mutex);
+
+   if (_eglGlobal.ClientExtensionString == NULL) {
+      size_t clientLen = strlen(_eglGlobal.ClientOnlyExtensionString);
+      size_t platformLen = strlen(_eglGlobal.PlatformExtensionString);
+
+      _eglGlobal.ClientExtensionString = (char *) malloc(clientLen + platformLen + 1);
+      if (_eglGlobal.ClientExtensionString != NULL) {
+         char *ptr = _eglGlobal.ClientExtensionString;
+
+         memcpy(ptr, _eglGlobal.ClientOnlyExtensionString, clientLen);
+         ptr += clientLen;
+
+         if (platformLen > 0) {
+            // Note that if PlatformExtensionString is not empty, then it will
+            // already have a leading space.
+            assert(_eglGlobal.PlatformExtensionString[0] == ' ');
+            memcpy(ptr, _eglGlobal.PlatformExtensionString, platformLen);
+            ptr += platformLen;
+         }
+         *ptr = '\0';
+      }
+   }
+   ret = _eglGlobal.ClientExtensionString;
+
+   mtx_unlock(_eglGlobal.Mutex);
+   return ret;
+}
+
+EGLBoolean
+_eglPointerIsDereferencable(void *p)
+{
+   uintptr_t addr = (uintptr_t) p;
+   const long page_size = getpagesize();
+#ifdef HAVE_MINCORE
+   unsigned char valid = 0;
+
+   if (p == NULL)
+      return EGL_FALSE;
+
+   /* align addr to page_size */
+   addr &= ~(page_size - 1);
+
+   if (mincore((void *) addr, page_size, &valid) < 0) {
+      _eglLog(_EGL_DEBUG, "mincore failed: %m");
+      return EGL_FALSE;
+   }
+
+   /* mincore() returns 0 on success, and -1 on failure.  The last parameter
+    * is a vector of bytes with one entry for each page queried.  mincore
+    * returns page residency information in the first bit of each byte in the
+    * vector.
+    *
+    * Residency doesn't actually matter when determining whether a pointer is
+    * dereferenceable, so the output vector can be ignored.  What matters is
+    * whether mincore succeeds. See:
+    *
+    *   http://man7.org/linux/man-pages/man2/mincore.2.html
+    */
+   return EGL_TRUE;
+#else
+   // Without mincore(), we just assume that the first page is unmapped.
+   return addr >= page_size;
+#endif
+}