Planet Debian
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Dirk Eddelbuettel: RcppArmadillo 15.6.2-1 on CRAN: New Upstream
Armadillo is a powerful and expressive C++ template library for linear algebra and scientific computing. It aims towards a good balance between speed and ease of use, has a syntax deliberately close to Matlab, and is useful for algorithm development directly in C++, or quick conversion of research code into production environments. RcppArmadillo integrates…
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Steinar H. Gunderson: Decompilation patterns, part 14: Strength increase
Let's look at the entire loop from yesterday: u16 spE10; u16 *var_v0_2; ... var_t1_2 = 0x7F; var_v0_2 = &spE10 + 0xFE; do { *var_v0_2 = 0; var_t1_2 -= 1; var_v0_2 -= 2; } while (var_t1_2 >= 0); What's going with the pointer arithmetic here? Why is it indexing out-of-bounds? The first thing to notice is that m2c doesn't really take into account that…
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Steinar H. Gunderson: Decompilation patterns, part 13: Reverse loop
Anyone who's read “bro-coder” C from before that was a name will recognize this idiom: var_t1_2 = 0x7F; ... do { ... var_t1_2 -= 1; } while (var_t1_2 >= 0); Why does the loop count backwards? It's because comparison with zero is cheaper on some (many) platforms. Some people would reverse the loop manually, but compilers quickly managed to do that…
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Dirk Eddelbuettel: RcppSimdJson 0.1.17 on CRAN: Updates
A brand new release 0.1.17 of the RcppSimdJson package is now on CRAN , and has been built for r2u and on r-universe . RcppSimdJson wraps the fantastic and genuinely impressive simdjson library by Daniel Lemire and collaborators. Via very clever algorithmic engineering to obtain largely branch-free code, coupled with modern C++ and newer compiler…
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Freexian Collaborators: Monthly report about Debian Long Term Support, September 2026 (by Santiago Ruano Rincón)
The Debian LTS Team, funded by [Freexian’s Debian LTS offering] ( https://www.freexian.com/lts/debian/) , is pleased to report its activities for September. Activity summary During the month of September, 20 contributors have been paid to work on Debian LTS (links to individual contributor reports are located below). The team released 41 DLAs fixing 1854…
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Reproducible Builds (diffoscope): diffoscope 334 released
The diffoscope maintainers are pleased to announce the release of diffoscope version 334 . This version includes the following changes: [ Chris Lamb ] * Fix a crash when using the latest versions of Androguard. Thanks, hc! (Closes: reproducible-builds/diffoscope#434) You find out more by visiting the project homepage .
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Matthew Garrett: Epic's EAC2 v2 seems fairly easily bypassable
Epic just announced the upcoming version 2 of their Linux implementation of Easy Anti-Cheat. It’s based on using the Linux eBPF security module to monitor what’s happening, and then a bunch of extra infrastructure to make sure this can’t be bypassed. The core part of this is requiring secure boot be enabled (ensuring that modified kernels can’t be used)…
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Steinar H. Gunderson: Decompilation patterns, part 12: __builtin_memcpy
Say you see this lovely chunk of decompiled code: var_v1 = &sp10 var_v0 = D_80010040; temp_s4 = var_v1; sp110 = &sp2C sp114 = &sp30 do { var_v1->unk0 = (s32) var_v0->unk0; var_v1->unk4 = (s32) var_v0[1]; var_v1->unk8 = (s32) var_v0[2]; var_v1->unkC = (s32) var_v0[3]; var_v0 += 0x10; var_v1 += 0x10; } while (var_v0 != &D_8001040[0x3C]); var_v1->unk0 = (s32)…
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Dirk Eddelbuettel: qlcal 0.1.4 on CRAN: Fresh Upstream Updates
The twenty-second release of the qlcal package arrivied at CRAN yesterday, and has been built for r2u as well as on r-universe . qlcal delivers the calendaring parts of QuantLib . It is provided (for the R package) as a set of included files, so the package is self-contained and does not depend on an external QuantLib library (which can be demanding to…
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Steinar H. Gunderson: Decompilation patterns, part 11: Irregular switch
Here's one that m2c usually gets right itself, but sometimes cannot: if (var_v1_7 != 1) { if (var_v1_7 < 2) { if (var_v1_7 != 0) { spF0 = 40; } else { vram_x = cmt46->vram_x; vram_y = cmt46->vram_y; spF0 = 40; } } else if (var_v1_7 != 2) { if (var_v1_7 != 3) { Repeated comparisons against the same variable, especially in a nested form that could be binary…
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Reproducible Builds: Reproducible Builds in September 2026
Welcome to the September 2026 report from the Reproducible Builds project! In our reports, we try to outline the most important things that we have been up to over the past month. As a quick recap about what problem our project intends to solve, whilst anyone may inspect the source code of free software for malicious flaws, almost all software is…
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Russ Allbery: Review: Ties That Bond in Gretna Green
Review: Ties That Bond in Gretna Green , by Linzi Day Series: Midlife Recorder #3 Publisher: Linzi Day Copyright: February 2023 ISBN: 9798376517017 Format: Kindle Pages: 616 Ties That Bond in Gretna Green is a self-published fantasy novel and the third book in the Midlife Recorder series. As with the previous book, it picks up almost immediately after…
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Freexian Collaborators: Debian Contributions: New experimental backend for autopkgtest using pconr, DebConf site visit and more! (by Anupa Ann Joseph)
Debian Contributions: 2026-09 Contributing to Debian is part of Freexian’s mission . This article covers the latest achievements of Freexian and their collaborators. All of this is made possible by organizations subscribing to our Long Term Support contracts and consulting services . DebConf site visit, by Stefano Rivera In preparation for DebConf 27…
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Dirk Eddelbuettel: RQuantLib 0.4.29 on CRAN: New QuantLib, Plus Small Fixes
A new release 0.4.29 of RQuantLib arrived on CRAN this evening, had already been built for r2u as well as on r-universe and has just been uploaded to Debian . QuantLib is a rather comprehensice free/open-source library for quantitative finance. RQuantLib connects (some parts of) it to the R environment and language, and has been part of CRAN for…
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Matthew Garrett: Linux Lockdown and Hibernation (again)
(This is an updated version of an older post - the introduction remains the same, the technical details are different) Linux draws a distinction between code running in kernel (kernel space) and applications running in userland (user space). This is enforced at the hardware level - in x86-speak 1 , kernel space code runs in ring 0 and user space code runs…
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Steinar H. Gunderson: Decompilation patterns, part 10: return var_v0
The v0 register on MIPS is special in that it is the return register (like rax is on x86-64), so when you see code like this: if (x == 3) { var_v0 = 1; } else if (y == 4) { ... var_v0 = 3; } var_v0 = 5; return var_v0; then you have to consider the possibility that the intended match is: if (x == 3) { return 1; } else if (y == 4) { ... return 3; } else {…
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Maytham Alsudany: Menus without JavaScript
This is more of a note to myself since I keep forgetting and "rediscovering" this technique every time I need it, but if it helps you, great! The JavaScript way is be to toggle displaying the menu based on a button click. For instance, here's an example in Svelte: [This interactive/preview is only available on the website.] (showMenu = !showMenu)}> {#if…
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Steinar H. Gunderson: Decompilation patterns part 9, sign extension
Today, for something completely different: s.x = (s16) ((s32) (temp_v0 << 0x10) >> 0x11); MIPS has 16-bit loads and stores, but not 16-bit (signed) arithmetic, so if it wants to do that, it needs to sign-extend to 32-bit first. And it does that by first shifting up by 16 so that the 16-bit sign bit is at the 32-bit sign bit, and then it can do an arithmetic…
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Steinar H. Gunderson: Decompiler patterns, part 8: Un-repetition of conditions
Today, for a slightly more complicated snippet, but still in the same general area; say you have code like this: x = (0x1000 - y) / 24; z = var_s5 < 5; if (x >= 0x81) { x = 0x80; z = var_s5 < 5; } var_s4 = 0; if (z == 0) { In particular, note the z = var_s5 < 5; repeated. Most likely, this is the compiler sticking stuff into branch delay slots, or else…
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Russ Allbery: Review: Daggerbound
Review: Daggerbound , by T. Kingfisher Series: Swordheart #2 Publisher: Bramble Copyright: 2026 ISBN: 1-250-40009-0 Format: Kindle Pages: 436 Daggerbound is a secondary-world fantasy and a sequel to Swordheart , although it follows different protagonists for most of the book. It's also a sort of sequel to the Clocktaur War duology in that one of the…
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Steinar H. Gunderson: Decompilation patterns, part 7: if to condition
A variation of the pattern from yesterday; say you have: if (x == 3) { y = 0; } else { y = 1; } When these are zero and one, sometimes this will give a better match, since booleans are evaluated as such: y = (x != 3); It's rare to have something else than zero or one work for this pattern (e.g. you would rarely write y = (x != 3) * 2 + 1 ).
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Tim Retout: Reading my solar inverter over RS485
For over ten years, the only way I have had of knowing what our solar panels are doing has been an impulse monitor on the generation meter, counting the flashes of its LED. It has always been a bit flaky due to battery changes or loose connections, and there has never been a way to see solar generation alongside the energy used by the rest of the house…
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Jelmer Vernooij: Mailsift: Extracting structured data from email messages
As a casual user of Gmail, I find its ability to recognize when I’ve received tickets, invoices, and flight confirmations, and to display this information in a structured way, very useful. Flights appear directly in Google Calendar, parcel delivery statuses are tracked, and reservations are easy to find at a glance. However, my main email address is not…
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Dirk Eddelbuettel: RcppSimdJson 0.1.16 on CRAN: Much Faster Again!
A brand new release 0.1.16 of the RcppSimdJson package is now on CRAN . RcppSimdJson wraps the fantastic and genuinely impressive simdjson library by Daniel Lemire and collaborators. Via very clever algorithmic engineering to obtain largely branch-free code, coupled with modern C++ and newer compiler instructions, it results in parsing gigabytes of JSON…
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Steinar H. Gunderson: Decompilation patterns, part 6: If-add-else
Often, m2c will spit out something like this: x = 3; if (a == 10) { x = 4; } This may be what was intended, but if it doesn't match (usually due to different register allocation; the rewrite itself is nearly always going to be taken, since it saves a branch on one of the paths), this is often a better rewrite: if (a == 10) { x = 4; } else { x = 3; } and in…
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Colin Watson: Free software activity in September 2026
My Debian contributions this month were all sponsored by Freexian. You can also support my work directly via Liberapay or GitHub Sponsors . OpenSSH I worked with upstream to remove libselinux linkage from /usr/sbin/sshd . I applied a fix from Mark Robillard Jr to fix reload logic when using sysvinit . groff I upgraded from 1.24.1 to 1.24.2, which fixed a…
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Russell Coker: Don’t Anthromorphise LLMs
Greg KH gave a great lecture for Kernel Recipies 2026 about the use of LLMs to find and fix bugs in kernel code [1] . I recommend that everyone watch this and I also think it’s important to note that hardly any of the lecture is really specific to kernel coding, it’s just that the Linux kernel is one of the highest profile large free software projects so it…
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Russell Coker: en-html.org is a Scam Site
Currently a scam group is sending out email to the administrators of web sites that link to a variety of dead domains. They claim to be the legitimate operators of the dead domains in question and request that the links change to mirrors of the web sites under en-html.org. Their end goal appears to game search engines by getting links from a lot of old web…
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Louis-Philippe Véronneau: Removing myself as a Lintian uploader in the next few weeks
A few days ago, a colleague reached out to me, asking if I could help draft a resolution on digital autonomy and free software for the upcoming renewal of our collective bargaining agreement. Although she's very politicised and generally a great individual, she is not a techie and we never really talked about these issues before. This took me by surprise. I…
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Reproducible Builds (diffoscope): diffoscope 333 released
The diffoscope maintainers are pleased to announce the release of diffoscope version 333 . This version includes the following changes: [ Johannes Schauer Marin Rodrigues ] * Add support for showing differences in POSIX.1-2001 PAX headers within .tar files. [ Chris Lamb ] * Re-order various parts of the tar comparator to make it easier to progressively…