Re: [PATCH v3 14/18] list: Permit context-unguarded access with list_empty_careful()

On Fri, 10 Jul 2026 at 10:10, Nilay Shroff <[email protected]> wrote:
>
> Hi Marco,
>
> On 7/9/26 12:00 PM, Christoph Hellwig wrote:
> > On Mon, Jul 06, 2026 at 07:44:16PM +0530, Nilay Shroff wrote:
> >> From: Marco Elver <[email protected]>
> >>
> >> With Context Analysis (viz. Clang's Thread Safety Analysis), list_heads
> >> that are __guarded_by(..) require holding the appropriate context lock
> >> when accessing and manipulating them via the list API. Because Clang's
> >> warning diagnostics do not perform inter-procedural analysis, this is
> >> enforced by Clang with -Wthread-safety-pointer in the caller at the call
> >> boundary; a warning is produced when passing a pointer to a guarded
> >> variable without holding the appropriate context locks:
> >
> > Same thing here, maybe try to get this to Linus late in the current
> > window as it's trivial and makes dependency management much easier.

It's not a bug fix, more of a feature, so I don't think this should be
sent in a post-rc1 PR (and Linus would likely reject it).

> > If that doesn't work, move it to the front of the series.
> >
> Would it be possible for you to send a pull request for Linus directly, or
> would it need to go through another maintainer?

Needs another maintainer.

> If you're able to send it directly, we also have patch 09/18 in this
> series that should go to Linus. In that case, I'd suggest including both
> patches in the same pull request.

list has no de-facto maintainer, so anyone could take it. My guess is
it could go through tip/locking/core since it's related to Context
Analysis...

... alas, this is more complex than it needs to be, esp. given it's
borderline to get this merged post-rc1.

> Otherwise, as Christoph suggested, I'll move these patches to the
> beginning of the series in the next revision.

I'd just move it to the beginning on the respin, given what I said above.

Thanks,
-- Marco