linux-kernel - Re: [RFC PATCH 0/4] net/io_uring: pass a kernel pointer via optlen_t to proto[

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Message-ID: <20250402133520.40451468@pumpkin>
Date: Wed, 2 Apr 2025 13:35:20 +0100
From: David Laight <david.laight.linux@...il.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Stefan Metzmacher <metze@...ba.org>, Jens Axboe <axboe@...nel.dk>, Pavel
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Subject: Re: [RFC PATCH 0/4] net/io_uring: pass a kernel pointer via
 optlen_t to proto[_ops].getsockopt()

On Tue, 1 Apr 2025 17:40:19 -0700
Linus Torvalds <torvalds@...ux-foundation.org> wrote:

> "
> 
> On Mon, 31 Mar 2025 at 13:11, Stefan Metzmacher <metze@...ba.org> wrote:
> >
> > But as Linus don't like 'sockptr_t' I used a different approach.  
> 
> So the sockptr_t thing has already happened. I hate it, and I think
> it's ugly as hell, but it is what it is.
> 
> I think it's a complete hack and having that "kernel or user" pointer
> flag is disgusting.

I have proposed a patch which replaced it with a structure.
That showed up some really hacky code in IIRC io_uring.

Using sockptr_t for the buffer was one thing, the generic code
can't copy the buffer to/from user because code lies about the length.

But using for the length is just brain-dead.
That is fixed size and can be copied from/to user by the wrapper.
The code bloat reduction will be significant.

	David