Learning PF_RING and netmap

Rusty Russell: A Model for Bitcoin Soft Fork Activation
TL;DR: There should be an option, taproot=lockintrue, which allows users to set lockin-on-timeout to true. It should not be the default, though. As stated in my previous post, we need actual consensus, not simply the appearance of consensus. I’m pretty sure we have that for taproot, but I would like a template we can use in future without endless debate each […]
Matthew Garrett: Making hibernation work under Linux Lockdown
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 in ring 3[2]. If you're running in ring 3 and you attempt to touch memory that's only accessible in ring 0, the […]
Rusty Russell: Bitcoin Consensus and Solidarity
Bitcoin’s consensus rules define what is valid, but this isn’t helpful when we’re looking at changing the rules themselves. The trend in Bitcoin has been to make such changes in an increasingly inclusive and conservative manner, but we are still feeling our way through this, and appreciating more nuance each time we do so. To use Bitcoin, you need to remain […]
Kees Cook: security things in Linux v5.8
Previously: v5.7 Linux v5.8 was released in August, 2020. Here’s my summary of various security things that caught my attention: arm64 Branch Target Identification Dave Martin added support for ARMv8.5’s Branch Target Instructions (BTI), which are enabled in userspace at execve() time, and all the time in the kernel (which required manually marking up a lot […]
Greg Kroah-Hartman: 8 bits are enough for a version number...
As was pointed out to us stable kernel maintainers last week, the overflow of the .y release number was going to happen soon, and our proposed solution for it (use 16 bits instead of 8), turns out to be breaking a userspace-visable api. As we can’t really break this, I did a release of the 4.4.256 and 4.9.256 releases today that contain nothing but a new ver […]
Greg Kroah-Hartman: Helping out with LTS kernel releases
A recent email thread about “Why isn’t the 5.10 stable kernel listed as supported for 6 years yet!” on the linux-kernel mailing list ended up generating a bunch of direct emails to me asking what could different companies and individuals due to help out. What exactly was I looking for here? Instead of having to respond to private emails with the same informa […]
James Bottomley: Deploying Encrypted Images for Confidential Computing
In the previous post I looked at how you build an encrypted image that can maintain its confidentiality inside AMD SEV or Intel TDX. In this post I’ll discuss how you actually bring up a confidential VM from an encrypted image while preserving secrecy. However, first a warning: This post represents the state of the art and includes patches that are certainly […]
Paul E. Mc Kenney: Parallel Programming: December 2020 Update
This release of Is Parallel Programming Hard, And, If So, What Can You Do About It? features numerous improvments: LaTeX and build-system upgrades (including helpful error checking and reporting), formatting improvements (including much nicer display of hyperlinks and of Quick Quizzes, polishing of numerous figures and tables, plus easier builds for A4 pape […]
James Bottomley: Building Encrypted Images for Confidential Computing
With both Intel and AMD announcing confidential computing features to run encrypted virtual machines, IBM research has been looking into a new format for encrypted VM images. The first question is why a new format, after all qcow2 only recently deprecated its old encrypted image format in favour of luks. The problem is that in confidential computing, the gue […]
Michael Kerrisk (manpages): man-pages-5.10 is released
Starting with this release, Alejandro (Alex) Colomar has joined me as project comaintainer, and we've released man-pages-5.10. The release tarball is available on kernel.org. The browsable online pages can be found on man7.org. The Git repository for man-pages is available on kernel.org.This release resulted from patches, bug reports, reviews, and comme […]