I have a library that I have ported from Windows, and is not a derivative work of Linux. The library is subject to copyright law, and I can't disclose the source. I would like to link a GPL application to this library, and want to know if the linking would cause the library to be GPL.

If the library becomes GPL, is there some other way (kernel loadable module?) that I can keep my library from becoming a work of GPL?

A GPL program can't force another program to become GPL simply because it interfaces with it. The only situation in which a program or library must become GPL is when GPL source code is used in it.

Of course, your situation seems to be the opposite of what the GPL is designed to deal with. The GPL aims to protect open source software by making sure closed source software doesn't abuse its open nature. In your case, the GPL software is using closed source libraries, not the other way around.

There's no way an unwilling person's code can be "automatically" appropriated and made GPL. The GPL uses existing copyright law as its foundation, which means that only the copyright holders themselves can choose to give the code a GPL license. What the GPL says though is that once some code is GPL-licensed, you can't use it or distribute it in any way that restricts the freedoms it provides (the GPL generally doesn't restrict private use; it's only in distribution that it becomes a concern). If you can't or won't give others the same freedom you received, then you simply can't use the GPL code.

The same goes for any copyrighted code. You can only use it in the ways that the copyright holder allows, or not at all.

So you don't have to worry about the code "becoming a work of GPL", but depending on how they are bundled, and on what the owner of the non-GPL'd code allows, you may or may not be able to freely distribute both the GPL and non-GPL code together. I'm not a copyright expert though, so I can't say for sure what the details would be in this case. You may need to consult with an expert for that.