RFR: 8365609: Null pointer dereference in src/java.desktop/share/native/common/java2d/opengl/OGLBlitLoops.c OGLBlitToSurfaceViaTexture()

[Alexander Zvegintsev]

On Thu, 21 Aug 2025 22:36:02 GMT, Phil Race <prr at openjdk.org> wrote:

> I don't know why we don't treat failing to find this symbol as a fatal error like we do for others such as this first one.

It looks like the `glib_check_version` was added but never used. The first instance of its use appears to be the added check for the methods used for Screencast. And it was overlooked that the `fp_glib_check_version` can be `null`.

The `glib_check_version` is [available since 2.6](https://docs.gtk.org/glib/func.check_version.html), and the 2.6.0 [was released in 2004](https://mail.gnome.org/archives/gnome-announce-list/2004-December/msg00036.html), so I guess we can safely replace the `dlsym` with the `dl_symbol`.
This will be better than remembering to protect it with a null check if we decide to use `glib_check_version` later somewhere else.



-        fp_glib_check_version = dlsym(gtk3_libhandle, "glib_check_version");
-        if (!fp_glib_check_version) {
-            dlerror();
-        }
+        fp_glib_check_version = dl_symbol("glib_check_version");

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PR Review Comment: https://git.openjdk.org/jdk/pull/26799#discussion_r2292407186