0172d9e322
In preparation for adding support for SRCU, rename "crit" to "rcu-rscs", rename "rscs" to "rcu-rscsi", and remove the restriction to only the outermost level of nesting. The name change is needed for disambiguating RCU read-side critical sections from SRCU read-side critical sections. Adding the "i" at the end of "rcu-rscsi" emphasizes that the relation is inverted; it links rcu_read_unlock() events to their corresponding preceding rcu_read_lock() events. The restriction to outermost nesting levels was never essential; it was included mostly to show that it could be done. Rather than add equivalent unnecessary code for SRCU lock nesting, it seemed better to remove the existing code. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com> Tested-by: Andrea Parri <andrea.parri@amarulasolutions.com>
51 lines
1.9 KiB
Plaintext
51 lines
1.9 KiB
Plaintext
// SPDX-License-Identifier: GPL-2.0+
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(*
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* Copyright (C) 2015 Jade Alglave <j.alglave@ucl.ac.uk>,
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* Copyright (C) 2016 Luc Maranget <luc.maranget@inria.fr> for Inria
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* Copyright (C) 2017 Alan Stern <stern@rowland.harvard.edu>,
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* Andrea Parri <parri.andrea@gmail.com>
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*
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* An earlier version of this file appeared in the companion webpage for
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* "Frightening small children and disconcerting grown-ups: Concurrency
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* in the Linux kernel" by Alglave, Maranget, McKenney, Parri, and Stern,
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* which appeared in ASPLOS 2018.
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*)
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"Linux-kernel memory consistency model"
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enum Accesses = 'once (*READ_ONCE,WRITE_ONCE*) ||
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'release (*smp_store_release*) ||
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'acquire (*smp_load_acquire*) ||
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'noreturn (* R of non-return RMW *)
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instructions R[{'once,'acquire,'noreturn}]
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instructions W[{'once,'release}]
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instructions RMW[{'once,'acquire,'release}]
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enum Barriers = 'wmb (*smp_wmb*) ||
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'rmb (*smp_rmb*) ||
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'mb (*smp_mb*) ||
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'rcu-lock (*rcu_read_lock*) ||
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'rcu-unlock (*rcu_read_unlock*) ||
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'sync-rcu (*synchronize_rcu*) ||
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'before-atomic (*smp_mb__before_atomic*) ||
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'after-atomic (*smp_mb__after_atomic*) ||
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'after-spinlock (*smp_mb__after_spinlock*) ||
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'after-unlock-lock (*smp_mb__after_unlock_lock*)
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instructions F[Barriers]
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(* Compute matching pairs of nested Rcu-lock and Rcu-unlock *)
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let rcu-rscs = let rec
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unmatched-locks = Rcu-lock \ domain(matched)
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and unmatched-unlocks = Rcu-unlock \ range(matched)
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and unmatched = unmatched-locks | unmatched-unlocks
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and unmatched-po = [unmatched] ; po ; [unmatched]
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and unmatched-locks-to-unlocks =
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[unmatched-locks] ; po ; [unmatched-unlocks]
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and matched = matched | (unmatched-locks-to-unlocks \
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(unmatched-po ; unmatched-po))
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in matched
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(* Validate nesting *)
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flag ~empty Rcu-lock \ domain(rcu-rscs) as unbalanced-rcu-locking
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flag ~empty Rcu-unlock \ range(rcu-rscs) as unbalanced-rcu-locking
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