Re: [RFC PATCH 00/11] Rust null block driver

From: Bart Van Assche <bvanassche@acm.org>
To: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Jens Axboe <axboe@kernel.dk>
Cc: "Keith Busch" <kbusch@kernel.org>,
	"Andreas Hindborg" <nmi@metaspace.dk>,
	"Christoph Hellwig" <hch@lst.de>,
	"Damien Le Moal" <Damien.LeMoal@wdc.com>,
	"Hannes Reinecke" <hare@suse.de>,
	lsf-pc@lists.linux-foundation.org,
	rust-for-linux@vger.kernel.org, linux-block@vger.kernel.org,
	"Matthew Wilcox" <willy@infradead.org>,
	"Miguel Ojeda" <ojeda@kernel.org>,
	"Alex Gaynor" <alex.gaynor@gmail.com>,
	"Wedson Almeida Filho" <wedsonaf@gmail.com>,
	"Boqun Feng" <boqun.feng@gmail.com>,
	"Gary Guo" <gary@garyguo.net>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Benno Lossin" <benno.lossin@proton.me>,
	"open list" <linux-kernel@vger.kernel.org>,
	gost.dev@samsung.com, "Daniel Vetter" <daniel@ffwll.ch>
Subject: Re: [RFC PATCH 00/11] Rust null block driver
Date: Fri, 5 May 2023 12:38:55 -0700	[thread overview]
Message-ID: <0931c4ba-a217-1422-7e6a-bb396ce45251@acm.org> (raw)
In-Reply-To: <CANiq72=3kGRy-3Lq5oxUEhu5d-377QrhuzhvoKRL+_QvbnJE7A@mail.gmail.com>

On 5/5/23 03:53, Miguel Ojeda wrote:
> Definitely, in the end subsystems know best if there is enough time
> available (from everybody) to pull it off. I only meant to say that
> the security angle is not the only benefit.
> 
> For instance, like you said, the error handling, plus a bunch more
> that people usually enjoy: stricter typing, more information on
> signatures, sum types, pattern matching, privacy, closures, generics,
> etc.

These are all great advantages of Rust.

One potential cause of memory corruption caused by block drivers is
misprogramming the DMA engine of the storage controller. This is something
no borrow checker can protect against. Only an IOMMU can protect against
the storage controller accessing memory that it shouldn't access. This is
not a criticism of Rust - I'm bringing this up because I think this is
something that is important to realize.

Bart.