Linus Torvalds started another development cycle for the Linux kernel, announcing the release of Linux 5.10-rc1, and this time with a historical twist. The new version of the kernel actually marks the end of a decades-old feature that was made redundant after developers discovered it was the source of security bugs.
It is about deset_fs() allowing the Linux kernel to override address spaces, which was very useful to do with Intel's 286 and 386 processors.
As Torvalds explained in your weekly kernel update, set_fs () checks "If a copy of user space actually goes to user space or kernel space". This is important because, as detailed in 2010 in CVE-2010-4258, it could be used to "overwrite arbitrary kernel memory locations and gain privileges."
The bug was fixed again in 2010 andOver time, chip designers began to improve memory management techniques. Torvalds wrote that this type of memory space overhead has been prohibited.
»We always have" set_fs () ", and not all architectures have been converted to the new standard, but this type of memory space overhead has been prohibited on x86, powerpc, s390 and RISC-V architectures and all work preliminary has been done in I hope that other architectures also move away from this historical model, although it may take a while to get rid of it
"Anyway, for the most part folks, that shouldn't matter at all, and it's mostly a little historical footnote that 5.10 is no longer based on the whole set_fs () pattern."
According to the reports, this version adds approximately 704,000 new lines of code and it resulted in the removal of 419,000 lines, making Linux 5.10-rc1 comparable in size to the largest Linux kernel ever (Linux 5.8).
"It appears to be a larger version than I expected, and although the merge window is smaller than that of version 5.8, it is not much smaller," said Torvalds. "And 5.8 was the most important post we ever did."
According to the typical Linux program, 5.10-rc1 will several weeks of troubleshooting will follow, with several Release Candidates released ahead of the stable kernel release scheduled for December.
The big changes in this version of the kernel include the End of Support for PowerPC 601 Processors, compatibility with Nvidia's Orin SOCs for use in autonomous cars and robots, orBetter graphics driver support on the processor Broadcom used in the Raspberry Pi 4, a Specter mitigation for Arm processors, virtualization tweaks, and bug fixes from the year 2038.
Since kernel version 5.6, released last March, The team has started offering solutions to solve the problem of the year 2038. This is a bug that was found in encoding long ago on Unix-like systems, including Linux, macOS, and other POSIX-compatible operating systems.
In these systems, the computation time is based on seconds elapsed since January 1, 1970 at 00:00:00 UTC (also called the epoch). A day will give, for example, 86.400 seconds and a year 31.536.000 seconds.
Fixes for XFS are expected for Linux kernel 5.10 shipped by Wong delay the 2038 error by 448 more years.
“The most important changes are two new functions for the metadata on disk: one to save short inode sizes in the AG to increase redundancy checks, but also to improve edit times; and a second function to support timestamps up to 2486, ”Darrick Wong wrote in his email to Torvalds.
The additional 448 years should be enough to find a long-term solution to this problem with the XFS file system. As noted by Linus Torvalds, the fixes have been incorporated.