Re: [RFC] Potential problem in qspinlock due to mixed-size accesses

[Thomas Haas]

On 12.06.25 16:55, Thomas Haas wrote:
> We have been taking a look if mixed-size accesses (MSA) can affect the 
> correctness of qspinlock.
> We are focusing on aarch64 which is the only memory model with MSA 
> support [1].
> For this we extended the dartagnan [2] tool to support MSA and now it 
> reports liveness, synchronization, and mutex issues.

--- cut off ---

ARM has recently fixed the issue on their side by strengthening the 
memory model (see 
https://github.com/herd/herdtools7/commit/2b7921a44a61766e23a1234767d28af696b436a0)

With the updated ARM-MSA model, Dartagnan does no longer find violations 
in qspinlock. No patches needed :)

With best regards,
Thomas