mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-17 09:43:59 +08:00
0031e38adf
This patch adds data-race detection to the Linux-Kernel Memory Model. As part of this effort, support is added for: compiler barriers (the barrier() function), and a new Preserved Program Order term: (addr ; [Plain] ; wmb) Data races are marked with a special Flag warning in herd. It is not guaranteed that the model will provide accurate predictions when a data race is present. The patch does not include documentation for the data-race detection facility. The basic design has been explained in various emails, and a separate documentation patch will be submitted later. This work is based on an earlier formulation of data races for the LKMM by Andrea Parri. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reviewed-by: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
85 lines
3.1 KiB
Plaintext
85 lines
3.1 KiB
Plaintext
// 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
|