| // 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 |
| |
| (* Redefine dependencies to include those carried through plain accesses *) |
| let carry-dep = (data ; rfi)* |
| let addr = carry-dep ; addr |
| let ctrl = carry-dep ; ctrl |
| let data = carry-dep ; data |
