KERNEL WATCH
Jon Masters summarises the latest happenings in the Linux kernel, so that you don’t have to.
L inus Torvalds closed the merge window for kernel 5.13, and released a series of Release Candidate kernels that have since settled down and stabilised ahead of the final release. Linus noted that there were “1,800+ developers and 14k+ non-merge [non-administrative] commits”, which is on the larger side as Linux development cycles go. Still, it’s been a fairly calm cycle so far without the usual kinds of scurrying that can happen by the time rc3 comes around.
As we reported last month, 5.13 gains initial support for Apple M1 bare metal hardware. In addition, it also includes a new option to randomise the location of the kernel stack on every system call, and the removal of the legacy /dev/kmem special file that traditionally allowed (privileged) applications to poke directly into kernel memory. While that might have helped old-school X Window servers and the like, it hasn’t been needed by the vast majority of users for a long time, and is an obvious target for security compromises. Removing such old interfaces is usually for the best.