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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 9 Jan 2019 21:07:51 -0000 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22036.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x09L7oQ418284656 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 9 Jan 2019 21:07:50 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9B0A4B2064; Wed, 9 Jan 2019 21:07:50 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7BC9EB2067; Wed, 9 Jan 2019 21:07:50 +0000 (GMT) Received: from paulmck-ThinkPad-W541 (unknown [9.70.82.88]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 9 Jan 2019 21:07:50 +0000 (GMT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id 04DFA16C6402; Wed, 9 Jan 2019 13:07:50 -0800 (PST) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, mingo@kernel.org Cc: stern@rowland.harvard.edu, parri.andrea@gmail.com, will.deacon@arm.com, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, willy@infradead.org, Luc Maranget , "Paul E . McKenney" Subject: [PATCH RFC LKMM 7/7] tools/memory-model: Dynamically check SRCU lock-to-unlock matching Date: Wed, 9 Jan 2019 13:07:48 -0800 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190109210706.GA27268@linux.ibm.com> References: <20190109210706.GA27268@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19010921-0068-0000-0000-000003800428 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010374; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000274; SDB=6.01144138; UDB=6.00595704; IPR=6.00924400; MB=3.00025055; MTD=3.00000008; XFM=3.00000015; UTC=2019-01-09 21:07:55 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19010921-0069-0000-0000-000047121826 Message-Id: <20190109210748.29074-7-paulmck@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-01-09_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901090168 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Luc Maranget 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. ] --- 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(-) 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 -- 2.17.1