Re: [PATCH] rust: introduce KVec::pop()

[Danilo Krummrich <dakr@kernel.org>]

On Mon, Dec 02, 2024 at 10:54:52AM +0100, Bernhard Kauer wrote:
> On Mon, Dec 02, 2024 at 10:06:58AM +0100, Greg KH wrote:
> > On Mon, Dec 02, 2024 at 09:57:58AM +0100, Bernhard Kauer wrote:
> > > Provides a simple stack together with push().
> > 
> > Why?
> 
> Sorry, I forgot the reasoning. 
> 
> Updating to v6.13 broke my external Rust module due to the switch from
> alloc::vec::Vec to kernel::alloc::Vec.  A trivial /s/Vec/KVec/ fixed most
> cases.  However, there is no pop() or any other safe way to remove entries
> from the vector.
> 
> So it looks like I either have to stick to unsafe code or add the
> functionality inside the kernel.
> 
> 
> > >  rust/kernel/alloc/kvec.rs | 28 ++++++++++++++++++++++++++++
> > >  1 file changed, 28 insertions(+)
> > 
> > What in-kernel code needs this?  Shouldn't you also submit this when
> > that happens?
> 
> Fair point.  Unfortunatelly my code is far from ready for inclusion.
> Would a samples/rust/some_example.rs be sufficient?

I don't think this is needed. You're providing an example that can be executed
as KUnit test already with your patch.

This is a pretty basic function and surely gonna be needed for other drivers in
the future as well.

IMHO, *for this* it's enough if you have something that aims for inclusion
upstream, as long as you reference it properly in the commit message.

- Danilo

> 
> 
> Thanks,
> 
> 	Bernhard
>