// 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