fix: In Linux CL/GL sharing, handle failed symbols lookup

In some cases we endup with GL being found but neither GLX or EGL
found and this currently leads to crash.

So to better handle this case (and others), we keep track if we
found symbols or not.

If we're asked if CL/GL sharing is supported we check the load worked.

If it's during an actual context creation we check what we were given
match what we could load and fail context property finalization if not.

If it's during an "info" request where we don't have any properties
yet, we return yes if either GLX or EGL was found.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

Author: smunaut

opencl/source/sharings/gl/linux/gl_sharing_linux.cpp

@@ -37,6 +37,9 @@ bool GLSharingFunctionsLinux::isOpenGlExtensionSupported(const unsigned char *pE
 }
 
 bool GLSharingFunctionsLinux::isOpenGlSharingSupported() {
+    if (glGetString == nullptr) {
+        return false;
+    }
 
     std::basic_string<unsigned char> vendor = glGetString(GL_VENDOR);
     const unsigned char intelVendor[] = "Intel";
@@ -72,6 +75,20 @@ bool GLSharingFunctionsLinux::isOpenGlSharingSupported() {
         }
     }
 
+    switch (glHDCType) {
+    case CL_GLX_DISPLAY_KHR:
+        if (!glXLoaded)
+            return false;
+        break;
+    case CL_EGL_DISPLAY_KHR:
+        if (!eglLoaded)
+            return false;
+        break;
+    default:
+        if (!glXLoaded && !eglLoaded)
+            return false;
+    }
+
     return true;
 }
 
@@ -102,13 +119,19 @@ GLboolean GLSharingFunctionsLinux::initGLFunctions() {
         glXGLInteropQueryDeviceInfo = glXGetProc["glXGLInteropQueryDeviceInfoMESA"];
         glXGLInteropExportObject = glXGetProc["glXGLInteropExportObjectMESA"];
         glXGLInteropFlushObjects = glXGetProc["glXGLInteropFlushObjectsMESA"];
+        glXLoaded = ((glXGLInteropQueryDeviceInfo != nullptr) &&
+                     (glXGLInteropExportObject != nullptr) &&
+                     (glXGLInteropFlushObjects != nullptr));
     }
 
     GlFunctionHelper eglGetProc(dynLibrary.get(), "eglGetProcAddress");
     if (eglGetProc.ready()) {
         eglGLInteropQueryDeviceInfo = eglGetProc["eglGLInteropQueryDeviceInfoMESA"];
         eglGLInteropExportObject = eglGetProc["eglGLInteropExportObjectMESA"];
         eglGLInteropFlushObjects = eglGetProc["eglGLInteropFlushObjectsMESA"];
+        eglLoaded = ((eglGLInteropQueryDeviceInfo != nullptr) &&
+                     (eglGLInteropExportObject != nullptr) &&
+                     (eglGLInteropFlushObjects != nullptr));
     }
 
     glGetString = (*dynLibrary)["glGetString"];

opencl/source/sharings/gl/linux/gl_sharing_linux.h

@@ -127,6 +127,10 @@ class GLSharingFunctionsLinux : public GLSharingFunctions {
     GLContext glHGLRCHandleBkpCtx = 0;
     GLDisplay glHDCHandle = 0;
 
+    // Readiness
+    bool glXLoaded = false;
+    bool eglLoaded = false;
+
     // GL functions
     PFNglGetString glGetString = nullptr;
     PFNglGetStringi glGetStringi = nullptr;

opencl/source/sharings/gl/linux/lin_enable_gl.cpp

@@ -54,8 +54,15 @@ bool GlSharingContextBuilder::finalizeProperties(Context &context, int32_t &errc
         return true;
 
     if (contextData->glHGLRCHandle) {
-        context.registerSharing(new GLSharingFunctionsLinux(contextData->glHDCType, contextData->glHGLRCHandle,
-                                                            nullptr, contextData->glHDCHandle));
+        GLSharingFunctionsLinux *sharing_fn = new GLSharingFunctionsLinux(contextData->glHDCType,
+                                                                          contextData->glHGLRCHandle,
+                                                                          nullptr, contextData->glHDCHandle);
+        if (!sharing_fn->isOpenGlSharingSupported()) {
+            delete sharing_fn;
+            errcodeRet = CL_INVALID_PROPERTY;
+            return false;
+        }
+        context.registerSharing(sharing_fn);
     }
 
     contextData.reset(nullptr);