Pre-test native window pointer for validity

[android-x86/frameworks-native.git] / opengl / libs / EGL / eglApi.cpp

diff --git a/opengl/libs/EGL/eglApi.cpp b/opengl/libs/EGL/eglApi.cpp
index d3bc14a..c2ac564 100644 (file)
--- a/opengl/libs/EGL/eglApi.cpp
+++ b/opengl/libs/EGL/eglApi.cpp
@@ -23,6 +23,7 @@
 
 #include <hardware/gralloc.h>
 #include <system/window.h>
+#include <sys/mman.h>
 
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
@@ -49,6 +50,10 @@
 
 using namespace android;
 
+// This extension has not been ratified yet, so can't be shipped.
+// Implementation is incomplete and untested.
+#define ENABLE_EGL_KHR_GL_COLORSPACE 0
+
 // ----------------------------------------------------------------------------
 
 namespace android {
@@ -82,7 +87,9 @@ extern char const * const gExtensionString  =
         "EGL_KHR_image_base "                   // mandatory
         "EGL_KHR_image_pixmap "
         "EGL_KHR_lock_surface "
+#if (ENABLE_EGL_KHR_GL_COLORSPACE != 0)
         "EGL_KHR_gl_colorspace "
+#endif
         "EGL_KHR_gl_texture_2D_image "
         "EGL_KHR_gl_texture_cubemap_image "
         "EGL_KHR_gl_renderbuffer_image "
@@ -93,6 +100,7 @@ extern char const * const gExtensionString  =
         "EGL_NV_system_time "
         "EGL_ANDROID_image_native_buffer "      // mandatory
         "EGL_KHR_wait_sync "                    // strongly recommended
+        "EGL_ANDROID_recordable "               // mandatory
         ;
 
 // extensions not exposed to applications but used by the ANDROID system
@@ -100,8 +108,7 @@ extern char const * const gExtensionString  =
 //      "EGL_IMG_hibernate_process "            // optional
 //      "EGL_ANDROID_native_fence_sync "        // strongly recommended
 //      "EGL_ANDROID_framebuffer_target "       // mandatory for HWC 1.1
-//      "EGL_ANDROID_recordable "               // mandatory
-
+//      "EGL_ANDROID_image_crop "               // optional
 
 /*
  * EGL Extensions entry-points exposed to 3rd party applications
@@ -363,10 +370,39 @@ EGLBoolean eglGetConfigAttrib(EGLDisplay dpy, EGLConfig config,
 }
 
 // ----------------------------------------------------------------------------
+// Utility procedure to test a NativeWindowType for validity before referencing
+// through the pointer.  It's not feasible to test for deliberate forgeries,
+// but this heuristic is good enough to test for basic accidental cases, using
+// the special "magic" value placed in a native-window structure.
+// ----------------------------------------------------------------------------
+EGLBoolean isValidNativeWindow(NativeWindowType window)
+{
+    ANativeWindow *nwindow = static_cast<ANativeWindow*>(window);
+    // the msync system call returns with ENOMEM error for unmapped memory
+    // pages.  This is used here as a way to test whether we can read through a
+    // pointer without getting a segfault.
+    uintptr_t pagesize = (uintptr_t) sysconf(_SC_PAGESIZE);
+    uintptr_t addr = ((uintptr_t)(&nwindow->common.magic)) & (~(pagesize - 1));
+    int rc = msync((void *)addr, pagesize, MS_ASYNC);
+    if (0 == rc) {
+        if (nwindow->common.magic == ANDROID_NATIVE_WINDOW_MAGIC)
+            return EGL_TRUE;
+        else
+            return EGL_FALSE;
+    }
+    if (ENOMEM == errno)
+        return EGL_FALSE;
+    ALOGE("error unexpected msync error: %s (%d)",
+                            strerror(-errno), errno);
+    return EGL_FALSE;
+}
+
+
+// ----------------------------------------------------------------------------
 // surfaces
 // ----------------------------------------------------------------------------
 
-// The EGL_KHR_gl_colorspace spec hasn't been published yet, so these haven't
+// The EGL_KHR_gl_colorspace spec hasn't been ratified yet, so these haven't
 // been added to the Khronos egl.h.
 #define EGL_GL_COLORSPACE_KHR           EGL_VG_COLORSPACE
 #define EGL_GL_COLORSPACE_SRGB_KHR      EGL_VG_COLORSPACE_sRGB
@@ -402,6 +438,10 @@ EGLSurface eglCreateWindowSurface(  EGLDisplay dpy, EGLConfig config,
     if (dp) {
         EGLDisplay iDpy = dp->disp.dpy;
 
+        if (!isValidNativeWindow(window)) {
+            ALOGE("EGLNativeWindow %p invalid", window);
+            return setError(EGL_BAD_NATIVE_WINDOW, EGL_NO_SURFACE);
+        }
         if (native_window_api_connect(window, NATIVE_WINDOW_API_EGL) != OK) {
             ALOGE("EGLNativeWindowType %p already connected to another API",
                     window);
@@ -427,7 +467,17 @@ EGLSurface eglCreateWindowSurface(  EGLDisplay dpy, EGLConfig config,
                     attr += 2) {
                 if (*attr == EGL_GL_COLORSPACE_KHR &&
                         dp->haveExtension("EGL_KHR_gl_colorspace")) {
-                    format = modifyFormatColorspace(format, *(attr+1));
+                    if (ENABLE_EGL_KHR_GL_COLORSPACE) {
+                        format = modifyFormatColorspace(format, *(attr+1));
+                    } else {
+                        // Normally we'd pass through unhandled attributes to
+                        // the driver. But in case the driver implements this
+                        // extension but we're disabling it, we want to prevent
+                        // it getting through -- support will be broken without
+                        // our help.
+                        ALOGE("sRGB window surfaces not supported");
+                        return setError(EGL_BAD_ATTRIBUTE, EGL_NO_SURFACE);
+                    }
                 }
             }
         }
@@ -458,7 +508,17 @@ EGLSurface eglCreateWindowSurface(  EGLDisplay dpy, EGLConfig config,
         if (attrib_list && dp->haveExtension("EGL_KHR_gl_colorspace")) {
             for (const EGLint* attr = attrib_list; *attr != EGL_NONE; attr += 2) {
                 if (*attr == EGL_GL_COLORSPACE_KHR) {
-                    format = modifyFormatColorspace(format, attr[1]);
+                    if (ENABLE_EGL_KHR_GL_COLORSPACE) {
+                        format = modifyFormatColorspace(format, *(attr+1));
+                    } else {
+                        // Normally we'd pass through unhandled attributes to
+                        // the driver. But in case the driver implements this
+                        // extension but we're disabling it, we want to prevent
+                        // it getting through -- support will be broken without
+                        // our help.
+                        ALOGE("sRGB window surfaces not supported");
+                        return setError(EGL_BAD_ATTRIBUTE, EGL_NO_SURFACE);
+                    }
                 }
             }
         }