Author: Steven Rostedt (Kernel maintainer)
Author: Paul E. McKenney (Kernel maintainer)
Author: Alexei Starovoitov (Kernel maintainer)
Author: Jose E. Marchesi (GNU toolchain)
The Linux kernel, which is by far one of the biggest, more complex and
more important programs around, is (still) mainly built using the GNU
Toolchain.
There is an intimate relationship between toolchain and kernel.
Compiling a huge, complex and specialized program such as the kernel
often implies facing challenging or unusual requirements on the
toolchain side. This includes security related requirements. Also, some
of the toolchain components interface directly with the kernel. In the
case of glibc, it even provides the main visible interface from the
kernel to userland programs. The support for BPF is also mainly Linux
kernel specific.
This relationship benefits both projects. For example, an actively
maintained toolchain can quickly include kernel specific
enhancements. And vice versa, the toolchain benefits from the associated
relevance that makes corporations support its development. It is
certainly not unusual for a feature introduced primarily for kernel
usage to also be very useful to other programs. Examples of this are the
support for patchable function entries, "asm goto", fentry , and several
security related features.
In order to improve this relationship a Toolchains Track has been
organized for some years now at the Linux PLumbers Conference. The aim
of the track is to fix particular toolchain (both GNU and LLVM) issues
which are of interest to the kernel and, ideally, find and agree on
solutions right away, during the track, making the best use of the
opportunity to discuss the issues live with kernel developers and
maintainers. The LPC toolchains track is proving very useful, although
it is not always easy to bring toolchain hackers there, given it is a
kernel specific conference.
We propose to have a Toolchain and Linux Kernel BoF during Cauldron this
year, with the participation of at least one Linux kernel
maintainer. The goals of the BoF are (a) to discuss about particular
requirements, desired features and on-going developments that are
relevant to the kernel and (b) to gather kernel related
questions/input/feedback from the toolchain developers so we can bring
the issues to the LPC Toolchains Track, which will be held later in the
year after Cauldron.
