From 9393998e9ee094f99d18783cc85c489e20f0e0e7 Mon Sep 17 00:00:00 2001 From: Luc Maranget Date: Thu, 27 Dec 2018 16:27:12 +0100 Subject: tools/memory-model: Dynamically check SRCU lock-to-unlock matching This commit checks that the return value of srcu_read_lock() is passed to the matching srcu_read_unlock(), where "matching" is determined by nesting. This check operates as follows: 1. srcu_read_lock() creates an integer token, which is stored into the generated events. 2. srcu_read_unlock() records its second (token) argument into the generated event. 3. A new herd primitive 'different-values' filters out pairs of events with identical values from the relation passed as its argument. 4. The bell file applies the above primitive to the (srcu) read-side-critical-section relation 'srcu-rscs' and flags non-empty results. BEWARE: Works only with herd version 7.51+6 and onwards. Signed-off-by: Luc Maranget Signed-off-by: Paul E. McKenney [ paulmck: Apply Andrea Parri's off-list feedback. ] Acked-by: Alan Stern --- tools/memory-model/linux-kernel.bell | 3 +++ tools/memory-model/linux-kernel.cat | 2 ++ tools/memory-model/linux-kernel.def | 2 +- 3 files changed, 6 insertions(+), 1 deletion(-) (limited to 'tools/memory-model') diff --git a/tools/memory-model/linux-kernel.bell b/tools/memory-model/linux-kernel.bell index 9c42cd9ddcb4..def9131d3d8e 100644 --- a/tools/memory-model/linux-kernel.bell +++ b/tools/memory-model/linux-kernel.bell @@ -73,3 +73,6 @@ 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 diff --git a/tools/memory-model/linux-kernel.cat b/tools/memory-model/linux-kernel.cat index 8dcb37835b61..95bf45f1215f 100644 --- a/tools/memory-model/linux-kernel.cat +++ b/tools/memory-model/linux-kernel.cat @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0+ (* + * Requires herd version 7.51+6 or higher. + * * Copyright (C) 2015 Jade Alglave , * Copyright (C) 2016 Luc Maranget for Inria * Copyright (C) 2017 Alan Stern , diff --git a/tools/memory-model/linux-kernel.def b/tools/memory-model/linux-kernel.def index 1d6a120cde14..0c3f0ef486f4 100644 --- a/tools/memory-model/linux-kernel.def +++ b/tools/memory-model/linux-kernel.def @@ -49,7 +49,7 @@ synchronize_rcu_expedited() { __fence{sync-rcu}; } // SRCU srcu_read_lock(X) __srcu{srcu-lock}(X) -srcu_read_unlock(X,Y) { __srcu{srcu-unlock}(X); } +srcu_read_unlock(X,Y) { __srcu{srcu-unlock}(X,Y); } synchronize_srcu(X) { __srcu{sync-srcu}(X); } // Atomic -- cgit v1.2.3-59-g8ed1b