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A highly enjoyable episode of FLOSS Weekly with some positive news about EU's CRA, a lot of @gregkh down to earth mentality and more :-)

" ... The majority runs " \o/

FLOSS Weekly 732: Update Your Kernels! - Greg Kroah-Hartman, Linux Kernel, Cyber Resilience Act

Episode webpage: https://twit.tv/shows/floss-weekly/episodes/732

Media file: https://pdst.fm/e/pscrb.fm/rss/p/cdn.twit.tv/audio/floss/floss0732/floss0732.mp3

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Edited 10 days ago

Greg released a bunch of new stable and longterm today with the usual "must upgrade" notice.

Among them is 6.2.16, which marks the end of the 6.2.y series; users are advised switching to 6.3.y.

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Christian Brauner 🦊🐺

Edited 1 month ago

"Linux Kernel Contribution Maturity Model" has finally made it into the kernel. Members of the Technical Advisory Board (TAB) of the Linux Foundation including @gregkh, @kees, @corbet, myself and others have been working together on this!

It will hopefully provide guidance for companies in supporting open source developers and maintainers effectively!
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=10a29eb658b3039eccfa6f249da079194f535a9a

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First talk I've given in person in a very long time, and it's on legal issues (the EU Cyber Resilience Act), I must have done something wrong in a past life:
https://kccnceu2023.sched.com/event/1Lnv0

Should be fun, if you are at KubeCon, stop by and ask questions, it's meant to be a discussion. A recording will be made public afterwards too.
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bpftrace fun question of the week I’ve been beating my head against for a while now.

Given the following bpftrace program:

tracepoint:syscalls:sys_enter_open,
tracepoint:syscalls:sys_enter_openat
{
        $g = "magic_command_to_exit_trace";
        $s = str(args->filename);
        printf("%s\n", $s);
        if ($s == $g) {
                exit();
        }
}

I get the lovely warning:

WARNING: Addrspace mismatch
    if ($s == $g) {

which I can understand. But what I can’t figure out is how to resolve this (hint, the program works just fine, when opening the “magic” file, the trace exits), as how to turn a literal string into the proper address space that args->filename is?

I’ve dug into too many bpftrace git commits to try to figure it out, to no luck. Anyone have a hint?

Oh, and if you want to see where this is used, it’s in this “fun” script: https://github.com/gregkh/gregkh-linux/blob/master/scripts/trace_kernel_build.sh

Warning, realpath takes a long time when processing millions of files, be patient when running the script.

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@brauner @monsieuricon In looking at the NL list, too many things on there that might trigger spam filters, or at the very least, rightly make people upset, so I'll stick with the default list for now.
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@brauner @monsieuricon Nice! You know you can localize the dice words, there's a wordlist_de.txt file in the package already on the distro I use, now to find a _nl.txt version...
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There's been a long nerd-sniping thread recently here from @monsieuricon where email message-ids were being discussed and generated in semi-interesting ways that ended up detouring me and @brauner into writing up competing python vs. perl scripts to get `git send-email` to properly use our new bespoke message ids:
https://social.kernel.org/notice/AU5IphRPUsQvvkx732

But why does any of this matter? As most everyone knows, Linux kernel development happens through email, and the Message-Id of an email is a unique identifier that is used to track messages in our patch handling tools and archives (see https://lore.kernel.org for the archives.) By crafting shorter-but-still-unique message ids it's easier to reference those messages in other places, and using words is just prettier overall than random UUID values (https://i.redd.it/64gl4t9s52ra1.jpg for an example)

Bonus to all of this is that people don't realize that most of the patches we send out are actually signed and can be validated as coming from the person that sent them. The tool we use for that looks at the body of the email, and a small subset of the Header tags in the email. By providing to the tool our custom Message-Id, that adds yet another portion of the email that is now able to be signed and validated, providing a tiny bit more security overall in the patch submission processes (very very tiny, I know, but it's real, as I found out when I submitted a patch with a broken message-id from what was signed and our tools caught it.)

Anyway, all of that is a long way of showing off a tiny core change to the kernel that allows some core structures to be moved to read-only memory that I've been working on for a few months now. Here's the last portion of that work being sucked off of the email archives and validated as coming from me:
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@brauner @dakkar @monsieuricon
Ok, all now working properly, and bonus, the message-id is now part of the signature on the email itself!
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@vbabka @brauner @dakkar @monsieuricon Yes, it's better than the "write once, and then rewrite again, and again, and again as the language updates itself and breaks previously-working scripts over the years" :)
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@brauner @monsieuricon @dakkar Ah, makes sense.

Anyway, rewrote it in perl as that way I have a chance to maintain it over time: https://paste.sr.ht/~gregkh/d8cd98966d8e5ef61161c0341b250d018b16e8bd
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@monsieuricon @brauner @dakkar Ah, so the python email library messed up again? Heck, if we are allowed to write full scripts here (and not just bash one-liners), let me try something on my own, worst case I write it in C...
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@brauner @monsieuricon @dakkar better, thanks!

But (you knew there was a but)…

message ids no longer have <> characters: `Message-Id: 2023040228-pastor-evidence-1269@gregkh Is that intentional and still a valid message id? As @monsieuricon said, email parsing is rough.

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@brauner @monsieuricon @dakkar Thanks!

In the never-ending series of things that really don’t matter but are fun, something is still not working. I just tried sending a patch out with this and the gmail server did not like it at all, and rewrote the message id with:

  Message-ID: <64293fdb.5d0a0220.58d3f.02e0SMTPIN_ADDED_BROKEN@mx.google.com>
X-Google-Original-Message-ID: <2023040245-stardust-obtain-0b4d@gregkh> usage.

Ah, in typing that out I see why, the original email header was:

Subject: [PATCH] MIPS: vpe-cmp: remove module owner pointer from struct class
 usage.

So the perl script changed that to:

Subject: [PATCH] MIPS: vpe-cmp: remove module owner pointer from struct class
Message-Id: <2023040245-stardust-obtain-0b4d@gregkh>
 usage.

And then vger promptly ate the message and never delivered it to the mailing list. I’ll hand-edit the subject line to be one line for now to get stuff done, but be aware of this if you use it as-is.

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@dakkar @monsieuricon @brauner Debugging a embedded perl script in a bash script for git run to use to send email for a Linux kernel patch over a social media message is yak shaving at it's finest.

Unfortunately, no, this change did not work, let me go dig up my old perl book from the upstairs library...
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@brauner @monsieuricon Much better. But not quite there, the script now strips out the "@" character and trailing text from the message id for some reason.

"2023040117-gem-unharmed-3194@gregkh" gets turned into "Message-Id: <2023040117-gem-unharmed-3194>"

But nice work with the inline perl, I have to use it for that reason alone!
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@brauner @monsieuricon Ok, I lied, I couldn't resist doing it "by hand" to see if it would work, and it did: https://lore.kernel.org/lkml/2023040126-blandness-duckling-bd55@gregkh/
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