Linux Plans To Stop Building a.out Support On Alpha & M68k To See If Anyone Cares

Back in 2019 that seems like an eternity ago with all that's gone on in the world, the Linux kernel deprecated a.out support. This executable / object code / shared library file format was used prior to the dominance of ELF but is seldom if ever used today. There have been pending patches to finally remove a.out from the kernel while the plan now is to stop building it on Alpha and Motorola 68000 targets to see if anyone notices/cares.

Upstream Linux kernel developers see no legitimate reason for keeping the a.out format support around and it's now been deprecated for three years. Only the Alpha and m68k architecture targets within the Linux kernel are still building with a.out support enabled.

So going one stop short of removing the a.out code outright, the plan is now via the Kconfig selections to stop building it for m68k and Alpha. This easy change will allow for seeing if anyone notices/cares about a.out support being removed on those architectures but otherwise if no one is complaining it likely means a future kernel can go ahead and remove that support code outright.

This patch has been picked up for Kees Cook's for-next/execve branch ahead of the Linux 5.18 merge window.

There has also been a discussion around the a.out support and other code that can be cleaned-up/removed once eliminating the a.out support. It's worth reiterating as with past articles this is just regarding the a.out file format support itself and doesn't impact modern code compilers that use an "a.out" name when no output name is specified as that's in ELF or other formats.