Re: [RFC 0/3] ABI spec - verification

[Dmitry Vyukov]

On Wed, Nov 16, 2016 at 6:37 PM,  <alexander.levin@xxxxxxxxxxx> wrote:
> As discussed at plumbers, having a standard spec for the kernel's ABI has
> quite a few uses and enough people wanted it to get the ball rolling.
>
> We agreed that it's desirable to have something that can be used from code
> rather than just a spec on paper both for validation and allowing other users
> (like fuzzers, userspace libraries, and various userspace tools) to build
> on that.
>
> What we ended up deciding on at plumbers is:
>
>  - I'll do a few kernel bits do demonstrate how we can validate the spec from
> the kernel.
>  - Dmitry Vyukov will provide a way to translate syzkaller's syscall
> documentation into something that can be easily used in the kernel and
> userspace.
>  - Various projects will attempt to integrate it to make sure that the
> framework works for them.
>
> Once those bits are done we can focus on getting the spec right, and we'll
> have a good way to validate our work both in userspace and in the kernel.
>
> This patchset is a basic draft of said kernel bits. I mostly want to make
> sure that Dmitry and myself are on the same page as to how integration will
> look like, but also to open it to criticism and suggestions (bikeshedding).


Looks like a good starting point!

Do you have a git repo with this somewhere? I have problems applying
the patches, seems that my gmail messed them with some weird escaping.

Is the intention that these descriptions are written by hand, or
generated from some DSL?
I benefited from easier to write descriptions, also I changed several
times what code generator generates without changing descriptions.
However, an additional level of indirection in the form of code
generator introduces own pain to maintain. So I am not too strong
here.

I will post other comments inline in the patches.

Thanks!

> Sasha Levin (3):
>   abi_spec: basic definitions of constraints, args and syscalls
>   abi_spec: hooks into syscall to allow pre and post checking
>   abi_spec: example spec for open(), placeholder for rest of syscalls
>
>  include/linux/syscalls.h      |   7 +-
>  include/uapi/linux/abi_spec.h |  58 ++++++
>  kernel/Makefile               |   2 +
>  kernel/abi_spec.c             | 456 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 522 insertions(+), 1 deletion(-)
>  create mode 100644 include/uapi/linux/abi_spec.h
>  create mode 100644 kernel/abi_spec.c
>
> --
> 2.7.4