Microsoft has published all changes and additions to the Linux kernel used in the kernel for the WSL 2 subsystem (Windows Subsystem for Linux v2). The second edition of WSL is a full-fledged Linux kernel, instead of an emulator translating Linux system calls into Windows system calls on the fly. The availability of source code allows enthusiasts to build their Linux kernel builds for WSL2, if desired, taking into account the nuances of this platform.
The Linux kernel shipped in WSL2 is based on release 4.19, which runs in a Windows environment using a virtual machine already used in Azure. Updates for the Linux kernel are delivered through the Windows Update mechanism and are tested in the Microsoft continuous integration infrastructure. Prepared patches include optimizations to reduce kernel startup time, reduce memory consumption, and leave the minimum required set of drivers and subsystems in the kernel.
In addition, Microsoft has applied for a linux-distros private mailing list that publishes information about new vulnerabilities at an early stage of their detection, allowing distributions to prepare to fix problems before public announcement. Access to the mailing list is required by Microsoft to obtain information about new vulnerabilities affecting such distributional-like assemblies as Azure Sphere, Windows Subsystem for Linux v2 and Azure HDInsight, which are not based on practices of existing distributions. Greg Kroah-Hartman, who is responsible for maintaining a stable kernel branch, is ready to act as a guarantor. The decision to grant access has not yet been made.
Get more info at GitHub.