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
-
Gnome Developers Consider Dropping RPM Support
In a move that might shock a lot of users, the Gnome development team has proposed the idea of going straight up Flatpak.
-
openSUSE Tumbleweed Ditches AppArmor for SELinux
If you're an openSUSE Tumbleweed user, you can expect a major change to the distribution.
-
Plasma 6.3 Now Available
Plasma desktop v6.3 has a couple of pretty nifty tricks up its sleeve.
-
LibreOffice 25.2 Has Arrived
If you've been hoping for a release that offers more UI customizations, you're in for a treat.
-
TuxCare Has a Big AlmaLinux 9 Announcement in Store
TuxCare announced it has successfully completed a Security Technical Implementation Guide for AlmaLinux OS 9.
-
First Release Candidate for Linux Kernel 6.14 Now Available
Linus Torvalds has officially released the first release candidate for kernel 6.14 and it includes over 500,000 lines of modified code, making for a small release.
-
System76 Refreshes Meerkat Mini PC
If you're looking for a small form factor PC powered by Linux, System76 has exactly what you need in the Meerkat mini PC.
-
Gnome 48 Alpha Ready for Testing
The latest Gnome desktop alpha is now available with plenty of new features and improvements.
-
Wine 10 Includes Plenty to Excite Users
With its latest release, Wine has the usual crop of bug fixes and improvements, along with some exciting new features.
-
Linux Kernel 6.13 Offers Improvements for AMD/Apple Users
The latest Linux kernel is now available, and it includes plenty of improvements, especially for those who use AMD or Apple-based systems.