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Diffstat (limited to 'tools/memory-model/linux-kernel.bell')
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diff --git a/tools/memory-model/linux-kernel.bell b/tools/memory-model/linux-kernel.bell new file mode 100644 index 000000000..5be86b102 --- /dev/null +++ b/tools/memory-model/linux-kernel.bell @@ -0,0 +1,84 @@ +// SPDX-License-Identifier: GPL-2.0+ +(* + * Copyright (C) 2015 Jade Alglave <j.alglave@ucl.ac.uk>, + * Copyright (C) 2016 Luc Maranget <luc.maranget@inria.fr> for Inria + * Copyright (C) 2017 Alan Stern <stern@rowland.harvard.edu>, + * Andrea Parri <parri.andrea@gmail.com> + * + * An earlier version of this file appeared in the companion webpage for + * "Frightening small children and disconcerting grown-ups: Concurrency + * in the Linux kernel" by Alglave, Maranget, McKenney, Parri, and Stern, + * which appeared in ASPLOS 2018. + *) + +"Linux-kernel memory consistency model" + +enum Accesses = 'once (*READ_ONCE,WRITE_ONCE*) || + 'release (*smp_store_release*) || + 'acquire (*smp_load_acquire*) || + 'noreturn (* R of non-return RMW *) +instructions R[{'once,'acquire,'noreturn}] +instructions W[{'once,'release}] +instructions RMW[{'once,'acquire,'release}] + +enum Barriers = 'wmb (*smp_wmb*) || + 'rmb (*smp_rmb*) || + 'mb (*smp_mb*) || + 'barrier (*barrier*) || + 'rcu-lock (*rcu_read_lock*) || + 'rcu-unlock (*rcu_read_unlock*) || + 'sync-rcu (*synchronize_rcu*) || + 'before-atomic (*smp_mb__before_atomic*) || + 'after-atomic (*smp_mb__after_atomic*) || + 'after-spinlock (*smp_mb__after_spinlock*) || + '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) + and unmatched-unlocks = Rcu-unlock \ range(matched) + and unmatched = unmatched-locks | unmatched-unlocks + and unmatched-po = [unmatched] ; po ; [unmatched] + and unmatched-locks-to-unlocks = + [unmatched-locks] ; po ; [unmatched-unlocks] + and matched = matched | (unmatched-locks-to-unlocks \ + (unmatched-po ; unmatched-po)) + 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 + +(* 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 + +(* Validate SRCU dynamic match *) +flag ~empty different-values(srcu-rscs) as srcu-bad-nesting + +(* Compute marked and plain memory accesses *) +let Marked = (~M) | IW | Once | Release | Acquire | domain(rmw) | range(rmw) | + LKR | LKW | UL | LF | RL | RU +let Plain = M \ Marked |