| // 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*) || | |
| 'after-srcu-read-unlock (*smp_mb__after_srcu_read_unlock*) | |
| 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 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 carry-srcu-data = (data ; [~ Srcu-unlock] ; rf)* | |
| let srcu-rscs = ([Srcu-lock] ; carry-srcu-data ; data ; [Srcu-unlock]) & loc | |
| (* Validate nesting *) | |
| flag ~empty Srcu-lock \ domain(srcu-rscs) as unmatched-srcu-lock | |
| flag ~empty Srcu-unlock \ range(srcu-rscs) as unmatched-srcu-unlock | |
| flag ~empty (srcu-rscs^-1 ; srcu-rscs) \ id as multiple-srcu-matches | |
| (* 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-value-match | |
| (* Compute marked and plain memory accesses *) | |
| let Marked = (~M) | IW | Once | Release | Acquire | domain(rmw) | range(rmw) | | |
| LKR | LKW | UL | LF | RL | RU | Srcu-lock | Srcu-unlock | |
| let Plain = M \ Marked | |
| (* Redefine dependencies to include those carried through plain accesses *) | |
| let carry-dep = (data ; [~ Srcu-unlock] ; rfi)* | |
| let addr = carry-dep ; addr | |
| let ctrl = carry-dep ; ctrl | |
| let data = carry-dep ; data |