Adding new OS support

Here are the common parts of syzkaller to edit in order to make syzkaller support a new OS kernel. However, there may be some specific changes that will be required for a given kernel (for example, gathering coverage from a given kernel, or some errors that might pop up and give a hint about what to tweak).

syz-executor

For each OS, there is this file executor/executor_GOOS.h where GOOS is the OS name. This file contains two important functions:

• os_init which is responsible for mapping a virtual address space for the calling process,
• execute_syscall which is responsible for executing system calls for a particular OS kernel.

These two functions, are called in executor/executor.cc, which is mainly responsible for executing the syscalls programs, and managing the threads in which the programs run.

executor_GOOS.h also contains functions related to that operating system such as functions that allow it to gather coverage information, detect bitness, etc. (Example: executor_linux.h ).

The intended function will be called according to the target kernel as defined by the macros in the executor/executor.cc file.

Build files pkg/

• The OS name is added to pkg/build/build.go along with the supported architecture

• Creating a file that builds the image for the targeted kernel under pkg/build/. This file contains functions for configuring the build of the bootable image, for building it, and for generate SSH keys which will be used by Syzkaller in order to access the VM. There is a file per each of the supported OSes by Syzkaller where the name pattern is GOOS.go.

• Adding the given target to the s/makefile/Makefile/.

Report files pkg/report/

Creating a file that reports build errors for the targeted kernel under pkg/report/. There is a file per each of the supported OSes by Syzkaller where the name pattern is GOOS.go.

Editing pkg/host/

• implement isSupported function that returns true for a supported syscall, it is located under pkg/host/GOOS.

Creating a file under sys/GOOS/

Creating a file init.go for the targeted kernel under sys/GOOS/that included the function initTarget that initializes the target and the different supported architectures.

Editing sys/syz-extract

Adding the new kernel name with already existing supported kernels to the file sys/syz-extract/extract.go.

Editing sys/targets

Adding the new kernel name with already existing supported kernels to the file targets.go which is located undersys/targets.

Editing vm/qemu

Adding the new kernel name with already existing supported kernels to the file qemo.go which is located under vm/qemu.

Syzkaller description & pseudo-syscalls

Check descriptions, and pseudo-syscalls.