Zack's Kernel News
Zack's Kernel News

Chronicler Zack Brown reports on the latest news, views, dilemmas, and developments within the Linux kernel community.
Extending Capabilities This Way and That
Eric W. Biederman wanted to find a good way to give one process a subset of the capabilities available to another process. Capabilities is a finer-grained set of permissions than regular ownership and read/write/execute permissions. It was defined in a POSIX draft that never became official, so the true nature and behavior of Unix capabilities has no official standard. It makes for craziness.
Eric's idea was to define a couple of new system calls, called fsyscall()
and fsyscall_create()
. The main call, fsyscall()
, would take another system call number as one parameter and a set of capabilities as another; then, it would run the targeted system call using the given set of capabilities, rather than those of the calling process.
He asked Andy Lutomirski's opinion, but Andy pointed out that system call numbers were not as clean as Eric thought. Specifically, Not all system calls were directly callable by number using the ABI (application binary interface). Andy said he was actually working on the problem from almost the opposite angle, to "have a way that one task can trap into a special mode in which another process can do syscalls on its behalf."
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
OpenMandriva Lx 6.0 Available for Installation
The latest release of OpenMandriva has arrived with a new kernel, an updated Plasma desktop, and a server edition.
-
TrueNAS 25.04 Arrives with Thousands of Changes
One of the most popular Linux-based NAS solutions has rolled out the latest edition, based on Ubuntu 25.04.
-
Fedora 42 Available with Two New Spins
The latest release from the Fedora Project includes the usual updates, a new kernel, an official KDE Plasma spin, and a new System76 spin.
-
So Long, ArcoLinux
The ArcoLinux distribution is the latest Linux distribution to shut down.
-
What Open Source Pros Look for in a Job Role
Learn what professionals in technical and non-technical roles say is most important when seeking a new position.
-
Asahi Linux Runs into Issues with M4 Support
Due to Apple Silicon changes, the Asahi Linux project is at odds with adding support for the M4 chips.
-
Plasma 6.3.4 Now Available
Although not a major release, Plasma 6.3.4 does fix some bugs and offer a subtle change for the Plasma sidebar.
-
Linux Kernel 6.15 First Release Candidate Now Available
Linux Torvalds has announced that the release candidate for the final release of the Linux 6.15 series is now available.
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.
-
Linux Kernel 6.14 Released
The latest Linux kernel has arrived with extra Rust support and more.