Re: [PATCH memory-model 1/8] tools/memory-model: Update some warning labels

Andrea Parri
2023-03-22T00:51:31Z

On Mon, Mar 20, 2023 at 06:02:39PM -0700, Paul E. McKenney wrote:
> From: Alan Stern <stern@rowland.harvard.edu>
>
> Some of the warning labels used in the LKMM are unfortunately
> ambiguous. In particular, the same warning is used for both an
> unmatched rcu_read_lock() call and for an unmatched rcu_read_unlock()
> call. Likewise for the srcu_* equivalents. Also, the warning about
> passing a wrong value to srcu_read_unlock() -- i.e., a value different
> from the one returned by the matching srcu_read_lock() -- talks about
> bad nesting rather than non-matching values.
>
> Let's update the warning labels to make their meanings more clear.
>
> Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> Reviewed-by: Jonas Oberhauser <jonas.oberhauser@huaweicloud.com>
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

Acked-by: Andrea Parri <parri.andrea@gmail.com>

Andrea

> ---
> tools/memory-model/linux-kernel.bell | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/tools/memory-model/linux-kernel.bell b/tools/memory-model/linux-kernel.bell
> index 70a9073dec3e..dc464854d28a 100644
> --- a/tools/memory-model/linux-kernel.bell
> +++ b/tools/memory-model/linux-kernel.bell
> @@ -53,8 +53,8 @@ let rcu-rscs = let rec
> in matched
>
> (* Validate nesting *)
> -flag ~empty Rcu-lock \ domain(rcu-rscs) as unbalanced-rcu-locking
> -flag ~empty Rcu-unlock \ range(rcu-rscs) as unbalanced-rcu-locking
> +flag ~empty Rcu-lock \ domain(rcu-rscs) as unmatched-rcu-lock
> +flag ~empty Rcu-unlock \ range(rcu-rscs) as unmatched-rcu-unlock
>
> (* Compute matching pairs of nested Srcu-lock and Srcu-unlock *)
> let srcu-rscs = let rec
> @@ -69,14 +69,14 @@ let srcu-rscs = let rec
> in matched
>
> (* Validate nesting *)
> -flag ~empty Srcu-lock \ domain(srcu-rscs) as unbalanced-srcu-locking
> -flag ~empty Srcu-unlock \ range(srcu-rscs) as unbalanced-srcu-locking
> +flag ~empty Srcu-lock \ domain(srcu-rscs) as unmatched-srcu-lock
> +flag ~empty Srcu-unlock \ range(srcu-rscs) as unmatched-srcu-unlock
>
> (* Check for use of synchronize_srcu() inside an RCU critical section *)
> flag ~empty rcu-rscs & (po ; [Sync-srcu] ; po) as invalid-sleep
>
> (* Validate SRCU dynamic match *)
> -flag ~empty different-values(srcu-rscs) as srcu-bad-nesting
> +flag ~empty different-values(srcu-rscs) as srcu-bad-value-match
>
> (* Compute marked and plain memory accesses *)
> let Marked = (~M) | IW | Once | Release | Acquire | domain(rmw) | range(rmw) |
> --
> 2.40.0.rc2
>