linux-kernel - Re: [PATCH v2 5/5] rust: enable `clippy::as

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAJ-ks9mJ=2hFxfWEkq+9b=atE89sHXa5NBcdVNRd3az6MSv0pA@mail.gmail.com>
Date: Thu, 13 Mar 2025 06:47:43 -0400
From: Tamir Duberstein <tamird@...il.com>
To: Benno Lossin <benno.lossin@...ton.me>
Cc: Masahiro Yamada <masahiroy@...nel.org>, Nathan Chancellor <nathan@...nel.org>, 
	Nicolas Schier <nicolas@...sle.eu>, Miguel Ojeda <ojeda@...nel.org>, 
	Alex Gaynor <alex.gaynor@...il.com>, Boqun Feng <boqun.feng@...il.com>, 
	Gary Guo <gary@...yguo.net>, Björn Roy Baron <bjorn3_gh@...tonmail.com>, 
	Andreas Hindborg <a.hindborg@...nel.org>, Alice Ryhl <aliceryhl@...gle.com>, 
	Trevor Gross <tmgross@...ch.edu>, Danilo Krummrich <dakr@...nel.org>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, "Rafael J. Wysocki" <rafael@...nel.org>, 
	Brendan Higgins <brendan.higgins@...ux.dev>, David Gow <davidgow@...gle.com>, 
	Rae Moar <rmoar@...gle.com>, Bjorn Helgaas <bhelgaas@...gle.com>, 
	Luis Chamberlain <mcgrof@...nel.org>, Russ Weight <russ.weight@...ux.dev>, Rob Herring <robh@...nel.org>, 
	Saravana Kannan <saravanak@...gle.com>, linux-kbuild@...r.kernel.org, 
	linux-kernel@...r.kernel.org, rust-for-linux@...r.kernel.org, 
	linux-kselftest@...r.kernel.org, kunit-dev@...glegroups.com, 
	linux-pci@...r.kernel.org, linux-block@...r.kernel.org, 
	devicetree@...r.kernel.org
Subject: Re: [PATCH v2 5/5] rust: enable `clippy::as_underscore` lint

On Wed, Mar 12, 2025 at 6:38 PM Benno Lossin <benno.lossin@...ton.me> wrote:
>
> On Wed Mar 12, 2025 at 11:24 PM CET, Tamir Duberstein wrote:
> > On Wed, Mar 12, 2025 at 5:30 PM Benno Lossin <benno.lossin@...ton.me> wrote:
> >>
> >> On Wed Mar 12, 2025 at 10:10 PM CET, Tamir Duberstein wrote:
> >> > On Wed, Mar 12, 2025 at 5:04 PM Tamir Duberstein <tamird@...il.com> wrote:
> >> >>
> >> >> On Wed, Mar 12, 2025 at 5:01 PM Benno Lossin <benno.lossin@...ton.me> wrote:
> >> >> > Always enable the features, we have `allow(stable_features)` for this
> >> >> > reason (then you don't have to do this dance with checking if it's
> >> >> > already stable or not :)
> >> >>
> >> >> It's not so simple. In rustc < 1.84.0 the lints *and* the strict
> >> >> provenance APIs are behind `feature(strict_provenance)`. In rustc >=
> >> >> 1.84.0 the lints are behind `feature(strict_provenance_lints)`. So you
> >> >> need to read the config to learn that you need to enable
> >> >> `feature(strict_provenance_lints)`.
> >>
> >> I see... And `strict_provenance_lints` doesn't exist in <1.84? That's a
> >> bit of a bummer...
> >>
> >> But I guess we could have this config option (in `init/Kconfig`):
> >>
> >>     config RUSTC_HAS_STRICT_PROVENANCE
> >>             def_bool RUSTC_VERSION >= 108400
> >>
> >> and then do this in `lib.rs`:
> >>
> >>     #![cfg_attr(CONFIG_RUSTC_HAS_STRICT_PROVENANCE, feature(strict_provenance_lints))]
> >
> > Yep! That's exactly what I did, but as I mentioned up-thread, the
> > result is that we only cover the `kernel` crate.
>
> Ah I see, can't we just have the above line in the other crate roots?

The most difficult case is doctests. You'd have to add this to every
example AFAICT.

> >> > Actually this isn't even the only problem. It seems that
> >> > `-Astable_features` doesn't affect features enabled on the command
> >> > line at all:
> >> >
> >> > error[E0725]: the feature `strict_provenance` is not in the list of
> >> > allowed features
> >> >  --> <crate attribute>:1:9
> >> >   |
> >> > 1 | feature(strict_provenance)
> >> >   |         ^^^^^^^^^^^^^^^^^
> >>
> >> That's because you need to append the feature to `rust_allowed_features`
> >> in `scripts/Makefile.build` (AFAIK).
> >
> > Thanks, that's a helpful pointer, and it solves some problems but not
> > all. The root Makefile contains this bit:
> >
> >> KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
> >> -Zallow-features= $(HOSTRUSTFLAGS)
> >
> > which means we can't use the provenance lints against these host
> > targets (including e.g. `rustdoc_test_gen`). We can't remove this
> > -Zallow-features= either because then core fails to compile.
> >
> > I'm at the point where I think I need more involved help. Want to take
> > a look at my attempt? It's here:
> > https://github.com/tamird/linux/tree/b4/ptr-as-ptr.
>
> I'll take a look tomorrow, you're testing my knowledge of the build
> system a lot here :)

We're guaranteed to learn something :)