executor: arm64: sys/linux: introduce syzos API

Allow guest payload to call syzos API functions. The available calls
are enumerated by SYZOS_API_* constants, and have a form of:

  struct api_call {
         uint64 call;
         uint64 struct_size;
         /* arbitrary call-related data here */
  };

Complex instruction sequences are too easy to break, so most of the time
fuzzer won't be able to efficiently mutate them.
We replace kvm_text_arm64 with a sequence of `struct api_call`, making it
possible to intermix assembly instructions (SYZOS_API_CODE) with
higher-level constructs.

Right now the supported calls are:
 - SYZOS_API_UEXIT - abort from KVM_RUN (1 argument: exit code, uint64)
 - SYZOS_API_CODE - execute an ARM64 assembly blob
                    (1 argument: inline array of int32's)

0 files changed, 0 insertions, 0 deletions