Comment by antoncohen | Hacker News Reader

Comment by antoncohen | Hacker News Reader

Parent Full thread

As the above poster said, Red Hat open sources everything. They buy proprietary software companies and open source the software. Red Hat officially sponsors the CentOS project.

I'm very familiar[1] with the "obfuscation" you linked to, and I think you are missing context. Red Hat used to ship their Linux kernel source RPMs as vanilla Linux kernels plus a series of patches. They switched to releasing the source RPMs as a fully patched kernel tree. They did this because Oracle started providing commercial support for RHEL (not just Oracle Linux), which is how Red Hat makes money. This had no impact on open source redistributions of RHEL, like CentOS, because they just compile the kernel source without modifying it. AFAIK the kernel is the only package they do that with.

[1] There was a kernel bug between RHEL 6 RC and GA, the RCs had individual patches, the GA kernel source RPM was pre-patched. Lack of patches made it harder to track down, but it was still possible by applying the patches to the RC kernel, then diffing the patched RC source against the GA source.

I don't understand, why did Red Hat need to start shipping their RHEL kernel source pre-patched just because Oracle started providing commercial support for RHEL? I don't understand how shipping pre-patched vs not pre-patched kernel source is related to Oracle providing support.

It makes it harder for Oracle (and, sadly, everyone else) to understand and support the patches.

The GPL requires that source be distributed in the preferred form for making modifications. One of the FAQ examples is that if you have a perl script that generates C code you can't just distribute the C code, you have to distribute the perl script that generates it.

IMO distributing only the pre-patched source of the kernel is the same kind of violation. The preferred form for making modifications is the original source plus separate patches, that's what the people who are working on that code use.

IANAL, but I work on the Red Hat kernel. I don't need the patches of the Red Hat kernel in order to make modifications to it. I need the patches from the upstream kernel in order to copy them to the Red Hat kernel, but I often use "--depth=1" clones of git trees, in other words clones without the "patches", and make modifications to them.

Patches are useful, of course. They are useful to understand the evolution of the software, to support it, etc. But they are not necessary in order to make modifications to the software. Ten-fifteen years ago it was actually the norm that open source software had private source control repositories and only made periodic releases as tarballs.

Sure, it's possible to work without the patches. Equally it's possible to make modifications to code that was generated by a Perl script - or even to modify binary code directly without having the source at all (I've seen it done). The salient question is: what is the preferred form for making modifications to the work? And certainly I'd always want to have the patch history available when working on a codebase.

Working on a codebase however is not what the license says. It says specifically "making modifications".

If you have the Perl script that generates C code, you get a benefit from being able to modify the Perl script rather than the C code. So the Perl script is the preferred form for making modifications.

If you have the history, you don't get any benefit from modifying the history. In this sense, having the history is not relevant to making modifications, only to studying the code (for example to make the same modifications on another branch/fork of the code, like I do with upstream patches, or like Oracle could do if they had the Red Hat patches).

Your could say that this phrasing is shortsighted, but note that neither Red Hat not Debian or anyone else has ever given the complete history to Linux or any other piece of software they distribute, but they had to give the complete base source tarball as distributed by the upstream project.

> In this sense, having the history is not relevant to making modifications, only to studying the code

Studying the code is the first step in making modifications. I would always want to have a working "git blame" before trying to modify a codebase, so that I could understand lines in the context of the changes they were part of before I modified those lines. I consider it considerably harder to modify a codebase when I don't have proper version control history available.

The rest of the comment explains what the license means by "preferred form for making modifications" and why the full commit history isn't it.

My intuition is the same as yours, but I also note that Oracle didn't sue Red Hat over it. This even though they are also among the Linux kernel copyright holders and are one of the most litigious companies known to the tech industry, PR consequences be damned.

So maybe their lawyers disagree with us? Or maybe they're institutionally allergic to being a GPL enforcement plaintiff, even in their own strategic interest.

Not sure that suing is in their strategic interest. Do they publish the oracle Linux kernel prepatched? If so, they wouldn’t want to set a precedent that Red Hat is breaking the GPL.

No idea if they do that, but good point if so.

Reply on news.ycombinator.com