Re: [PATCH v10 6/8] rust: file: add `FileDescriptorReservation`
From: Al Viro
Date: Sun Sep 15 2024 - 18:05:53 EST
On Sun, Sep 15, 2024 at 11:01:26PM +0100, Al Viro wrote:
> There's not a lot of binary formats (5 of those currently -
> all in fs/binmt_*.c), but there's nothing to prohibit more
binfmt_*.c, sorry.
> of them. If somebody decides to add the infrastructure for
> writing those in Rust, begin_new_exec() wrapper will need
> to be documented as "never call that in scope of reserved
> descriptor". Maybe by marking that wrapper unsafe and
> telling the users about the restriction wrt descriptor
> reservations, maybe by somehow telling the compiler to
> watch out for that - or maybe the constraint will be gone
> by that time.
>
> In any case, the underlying constraint ("a thread with
> reserved descriptors should not try to get a private
> descriptor table until all those descriptors are disposed
> of one way or another") needs to be documented.
>