From a3f600d92da564ad35f237c8aeab268ca49377cc Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 15 Nov 2018 11:20:37 -0500 Subject: tools/memory-model: Add SRCU support Add support for SRCU. Herd creates srcu events and linux-kernel.def associates them with three possible annotations (srcu-lock, srcu-unlock, and sync-srcu) corresponding to the API routines srcu_read_lock(), srcu_read_unlock(), and synchronize_srcu(). The linux-kernel.bell file now declares the annotations and determines matching lock/unlock pairs delimiting SRCU read-side critical sections, and it also checks for synchronize_srcu() calls inside an RCU critical section (which would generate a "sleeping in atomic context" error in real kernel code). The linux-kernel.cat file now adds SRCU-induced ordering, analogous to the existing RCU-induced ordering, to the gp and rcu-fence relations. Curiously enough, these small changes to the model's .cat code are all that is needed to describe SRCU. Portions of this patch (linux-kernel.def and the first hunk in linux-kernel.bell) were written by Luc Maranget. Signed-off-by: Alan Stern CC: Luc Maranget Signed-off-by: Paul E. McKenney Tested-by: Andrea Parri --- tools/memory-model/linux-kernel.bell | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) (limited to 'tools/memory-model/linux-kernel.bell') diff --git a/tools/memory-model/linux-kernel.bell b/tools/memory-model/linux-kernel.bell index 353c8d68e030..9c42cd9ddcb4 100644 --- a/tools/memory-model/linux-kernel.bell +++ b/tools/memory-model/linux-kernel.bell @@ -33,6 +33,12 @@ enum Barriers = 'wmb (*smp_wmb*) || 'after-unlock-lock (*smp_mb__after_unlock_lock*) instructions F[Barriers] +(* SRCU *) +enum SRCU = 'srcu-lock || 'srcu-unlock || 'sync-srcu +instructions SRCU[SRCU] +(* All srcu events *) +let Srcu = Srcu-lock | Srcu-unlock | Sync-srcu + (* Compute matching pairs of nested Rcu-lock and Rcu-unlock *) let rcu-rscs = let rec unmatched-locks = Rcu-lock \ domain(matched) @@ -48,3 +54,22 @@ let rcu-rscs = let rec (* Validate nesting *) flag ~empty Rcu-lock \ domain(rcu-rscs) as unbalanced-rcu-locking flag ~empty Rcu-unlock \ range(rcu-rscs) as unbalanced-rcu-locking + +(* Compute matching pairs of nested Srcu-lock and Srcu-unlock *) +let srcu-rscs = let rec + unmatched-locks = Srcu-lock \ domain(matched) + and unmatched-unlocks = Srcu-unlock \ range(matched) + and unmatched = unmatched-locks | unmatched-unlocks + and unmatched-po = ([unmatched] ; po ; [unmatched]) & loc + and unmatched-locks-to-unlocks = + ([unmatched-locks] ; po ; [unmatched-unlocks]) & loc + and matched = matched | (unmatched-locks-to-unlocks \ + (unmatched-po ; unmatched-po)) + 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 + +(* Check for use of synchronize_srcu() inside an RCU critical section *) +flag ~empty rcu-rscs & (po ; [Sync-srcu] ; po) as invalid-sleep -- cgit v1.2.3