Re: [PATCH v5 15/36] srcu: Support Clang's context analysis

On Mon, Jan 26, 2026 at 10:54:56AM -0800, Bart Van Assche wrote:

> Has it ever been considered to add support in the clang compiler for a
> variant of __must_hold() that expresses that one of two capabilities
> must be held by the caller? I think that would remove the need to
> annotate SRCU update-side code with __acquire_shared(ssp) and
> __release_shared(ssp).

Right, I think I've asked for logical operators like that. Although I
think it was in the __guarded_by() clause rather than the __must_hold().
Both || and && would be nice to have ;-)

Specifically, I think I asked for something like:

        cpumask_t       cpus_allowed __guarded_by(pi_lock && rq->__lock)
                                     __guarded_shared_by(pi_lock || rq->__lock);


I think Marco's suggestion was to use 'fake' locks to mimic those
semantics.