Posts by mattst88@fosstodon.org
(DIR) Post #AWTF4pkC4M3YtTOJV2 by mattst88@fosstodon.org
2023-06-07T23:06:48Z
1 likes, 0 repeats
The author of the freelist allocator puts together a merge request with a fix and a new unit test to prevent this sort of thing from ever happening again (https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23501)With that patch applied, 249 tests in GTK's test suite that were failing now pass on SPARC64.What of the other couple tests?
(DIR) Post #AWTF4qQNXVnh0J80Fk by mattst88@fosstodon.org
2023-06-07T23:23:11Z
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In one I find that the unaligned access is again in Mesa. It's a pretty typical pointer-aliasing bug, but for some additional complication it occurs in some code generated at build-time by a Python program.I make a merge request to fix it (https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23482) after confirming that the unit test passes. The commit I reference in the "Fixes: ..." tag in the commit message is from 2010.The next unit test fails with an unaligned access in GTK itself, finally :)
(DIR) Post #AWTF4r8Ku4xjCdh6lk by mattst88@fosstodon.org
2023-06-07T23:29:37Z
1 likes, 0 repeats
So in order to fix some unaligned accesses I noticed in #GTK on DEC #Alpha, I- used a SPARC64 system- discovered that gdb is broken on SPARC64- bisected and reported the gdb regression, which happened nearly 2 years ago- found a legitimate heisenbug in Mesa and reported it after fully understanding it- reviewed the fix and unit test, confirmed that it fixes the problem and the unit tests now pass- debugged a strict-aliasing violation in Mesa and made a merge request fixing a bug from 2010
(DIR) Post #AWTF4tMac3YI7QNWGO by mattst88@fosstodon.org
2023-06-07T23:31:44Z
1 likes, 0 repeats
I just reran the GTK test suite on Alpha with the patches applied, and found out that there are more. Many, many more. /o\The saga continues...Edit: I was wrong! I failed to apply the second patch. With it applied, the test suite passes and only a single test has unaligned accesses (which is the one I was aware of already)Ok: 722Expected Fail: 0Fail: 0Unexpected Pass: 0 Skipped: 1Timeout: 0
(DIR) Post #AXdbQKoaE6RL1HvBC4 by mattst88@fosstodon.org
2023-07-13T00:40:42Z
1 likes, 0 repeats
Another day, another bizarre software discovery.Apparently #Gentoo's sys-apps/sandbox (which ensures ebuilds don't make a mess outside of their build "sandbox") had a huge performance regression which caused webkit-gtk build times to go from 9 minutes to 1 hour.After collecting a ton of data, applying patches, reverting patches, etc, I filed https://bugs.gentoo.org/910273 and it seems we have a fix.But I don't know how it's fixing things!
(DIR) Post #AXdbQLjIpDoHrCSTbM by mattst88@fosstodon.org
2023-07-13T00:44:29Z
0 likes, 1 repeats
The proposed patch removes the use of the faccessat() function and instead relies on fstatat64().The system I'm testing on is a 64-core/128-thread beast, and I found that building with -j32 is actually significantly faster than with -j128 (39 minutes vs 1 hour).So the faccessat() function must be causing some sort of serialization that essentially causes a denial of service with that many jobs?Any guesses what is going on here?#linux, #glibc, #gentoo
(DIR) Post #AXpUGUFKs21NgxwbR2 by mattst88@fosstodon.org
2023-07-18T20:10:25Z
1 likes, 0 repeats
Any day you have to `git bisect skip` is not a good day. #git
(DIR) Post #AYanecC8Jqr43c1UXI by mattst88@fosstodon.org
2023-08-10T15:50:49Z
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I like #Gentoo and I enjoy being a developer and package maintainer. The distro offers incredible flexibility to configure your system in any way you like.But I really wish that didn't attract complete nutters who want to run Linux with mostly modern software but e.g. don't want udev on their systems.(Similar situations arise with dbus, rust, etc., to say nothing of systemd)
(DIR) Post #AYanedTBZw5c0n0ckq by mattst88@fosstodon.org
2023-08-10T15:58:13Z
1 likes, 0 repeats
Recent hilarity (from the same user, no less!)- Package failed to build because `QtCore/qsystemdetection.h` was missing. Turns out the user didn't want anything related to systemd on his system, so he was removing anything that matched *systemd*.- User wanted to be able to build Xorg with GLX support but *not* DRI, because it would save 0.4 MiB (12.4 MiB on-disk vs 12.4 MiB), and somehow this configuration was supposed to play Steam games.
(DIR) Post #AYaneeTDrHiH7C2AS0 by mattst88@fosstodon.org
2023-08-10T15:51:28Z
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Fine, you want to run #Gentoo built with clang and link-time optimization; linked with mold; using musl libc, libressl, slibtool; maximum hardened CFLAGS, SELinux, all on an aarch64 system runnning in big-endian mode. But please, just use udev.
(DIR) Post #ApLTsLNeyeHD4wm0m0 by mattst88@fosstodon.org
2024-12-22T17:58:39Z
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@mherrb agreed. This has been a common problem in #Gentoo. Some users think they're making their systems more secure by disabling IPv6 on the small set of packages that allow this, but if there's any benefit at all it should come from just disabling IPv6 in the kernel.To that end, we have been removing the IPv6 USE flag from packages.
(DIR) Post #ApLTsNWb0Oc3jEyAym by mattst88@fosstodon.org
2024-12-23T01:15:32Z
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@ScottE @mherrb You should have a look at what `--enable-ipv6` actually controls in packages. It's almost always just selecting between code-that-supports-ipv4-and-ipv6 and code-that-supports-ipv4 only.There's really not an advantage to disabling IPv6 in most packages. If you want to disable IPv6, just turn it off in the kernel. That's the only thing you can reasonably do since many packages unconditionally support IPv6 anyway.
(DIR) Post #ApLTsPB2rUYwqytzfM by mattst88@fosstodon.org
2024-12-23T18:19:14Z
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@ScottE @mherrb I'm not aware of any packages breaking if the kernel has IPv6 disabled, regardless of USE=ipv6 status. Are you?AFAICT, no, `--disable-ipv6` in nearly all packages does what I said before: it selects between code that supports IPv4 & IPv6 and code that only supports IPv4.
(DIR) Post #ApLTsPrwI0sF00yFWa by mattst88@fosstodon.org
2024-12-23T18:22:22Z
1 likes, 0 repeats
@ScottE @mherrb This is a good example of something I've noticed. If you give users a knob, they'll turn it even if they have no idea what it does.#Gentoo should provide knobs that make sense and provide some valuable trade-off. Gentoo shouldn't provide knobs that don't do that (and instead just offer additional ways to break your system).
(DIR) Post #ApLTuycs2EINNK8xc0 by mattst88@fosstodon.org
2024-12-22T19:42:38Z
1 likes, 0 repeats
@duxsco @mherrb Yeah, I don't think this makes things more secure. I think the people who think disabling IPv6 makes things more secure are probably not that familiar with it and are concerned that they might not be setting up firewalls properly, etc.
(DIR) Post #AtpTIj04OfqQEk1ha4 by mattst88@fosstodon.org
2025-05-06T21:03:05Z
1 likes, 0 repeats
@libreoffice Has Apache or anyone at Apache ever given a statement about why they haven't (or won't) close down OpenOffice and/or donate the name to The Document Foundation? Presumably y'all have asked them.
(DIR) Post #AuqLFVpkwE66aqHXRw by mattst88@fosstodon.org
2025-06-06T04:57:31Z
1 likes, 0 repeats
@xgqt you're really posting links to this trash?
(DIR) Post #AzFuxk74gadmi9ZnJg by mattst88@fosstodon.org
2025-10-16T03:50:45Z
1 likes, 0 repeats
@whot I'm new to AI coding agents -- is CLAUDE.md subsequently used by Claude to understand the project?If so... does that mean that errors in the AI-generated CLAUDE.md can result in further errors when using Claude?
(DIR) Post #B39GCjhhxyXaNWyjpo by mattst88@fosstodon.org
2026-02-07T19:30:05Z
0 likes, 1 repeats
After a ton of work, I've finally gotten over my perfectionism and made https://github.com/mattst88/ip32prom-decompiler public.It decompiles the PROM firmware for the Silicon Graphics O2 (IP32) and reassembles it into a bit-identical image.Even if that doesn't sound interesting to you, the README and reverse-engineering document should make for a fun read.#sgi #reverseEngineering
(DIR) Post #B39GCpXeGI3iU4JmzI by mattst88@fosstodon.org
2026-02-09T03:04:06Z
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Turned the docs into a blog post: https://mattst88.com/blog/2026/02/08/Reverse_Engineering_the_PROM_for_the_SGI_O2/