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McKenney" , Sasha Levin Subject: [PATCH AUTOSEL for 4.15 099/102] locking/locktorture: Fix num reader/writer corner cases Thread-Topic: [PATCH AUTOSEL for 4.15 099/102] locking/locktorture: Fix num reader/writer corner cases Thread-Index: AQHTsz57+5ByuCAQuEyPMOuTXQoqQw== Date: Sat, 3 Mar 2018 22:25:07 +0000 Message-ID: <20180303222318.26006-99-alexander.levin@microsoft.com> References: <20180303222318.26006-1-alexander.levin@microsoft.com> In-Reply-To: <20180303222318.26006-1-alexander.levin@microsoft.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [52.168.54.252] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;MW2SPR01MB06;6:Tje8h+3Z1DVdcOnaBJz30SABQs2l5OBK9nQqzBvhag1NnLOhkagSLBc08d+/GRWASl33/anq+yNbFciiY4bFDijnOycO7bOqkT4ZFaHDHY6XKredvk7n8CoJpzjON2G2OCzHnC4GLiUH7SodEhlOvy9Lj5P9R6uahi0nes3DH64KtOjpE3oNo/5ovzeU7TDzHwwZarFw6jK8sHCFCkve297ddeTHOqzf/RWdeV7XXsgjsSzQEd2mkVdszZXcENAVxq6TEHIaIEjRT7qilBi/oIr/rKBFDhY9KjRu4hWt5djTflVKCYrmNqyXQ5I3SFhllWPHokFQ1E6g2HCkUlUiWiaHbM0J58aSlrZ6ZHnX1ngbSvnbMqthB+PV/vpkpTLx;5:SK0Jf0S5KZqSt93jm3kyf14N+d19js3nvyT2RSfxk/BcJPHN0NS1cR42Wj3GNp/EZcLK2uXrpQRVMBW1mKXtcHbunuwVNQkYUQo70ymaMVFx2UkGSuXI7M4Jf2edVzutoghYS2FLtf6pSrrJ4K8uGq8AmvU8KRBoIYqxkNeu5dE=;24:3c9EaGxBLMjYXGzkLrBzLO04hyEKq+/YMfIGYrAwgLwRd951Kq/46AEg8zLb+p4a48hArv/8UTdPLBexaebkpYLv8RSE/HynIEtBRjKS+Ok=;7:7o+umStXLBSkjdP+t8V7mxsSPrX26j5nzW70gGj5NyoXngm0hNsWVOMZ2T0mJzMAZNQKNf7L506cttiP8O5cS9qnVxkllCFZnM1BG4nGjfx6Y+NCAgjw/qL+rqRERtCzx2N1xXkSHQsgKSDjkMPVyArCD21fo9qSn865FGj1Cz9y04FgtOfQuoUR9uDOvHLLoGzNidEtY+pDJkehwKu6ejfDi0NYxjlT3491H6Rw/E3ClzLyMN/D9smKEa+uJAP0 x-ms-office365-filtering-ht: Tenant x-ms-office365-filtering-correlation-id: 79b8bcad-1807-4386-6101-08d5815601d5 x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(4534165)(4627221)(201703031133081)(201702281549075)(48565401081)(5600026)(4604075)(3008032)(2017052603307)(7193020);SRVR:MW2SPR01MB06; x-ms-traffictypediagnostic: MW2SPR01MB06: authentication-results: spf=none (sender IP is ) smtp.mailfrom=Alexander.Levin@microsoft.com; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(28532068793085)(180628864354917)(89211679590171)(104084551191319); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(8211001083)(61425038)(6040501)(2401047)(5005006)(8121501046)(3002001)(10201501046)(93006095)(93001095)(3231220)(944501244)(52105095)(6055026)(61426038)(61427038)(6041288)(20161123562045)(20161123560045)(20161123558120)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123564045)(6072148)(201708071742011);SRVR:MW2SPR01MB06;BCL:0;PCL:0;RULEID:;SRVR:MW2SPR01MB06; x-forefront-prvs: 0600F93FE1 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(376002)(366004)(39380400002)(396003)(346002)(39860400002)(189003)(199004)(68736007)(2900100001)(97736004)(107886003)(36756003)(1076002)(76176011)(86612001)(6666003)(6116002)(99286004)(22452003)(10090500001)(3280700002)(105586002)(2950100002)(3846002)(26005)(2501003)(6506007)(4326008)(305945005)(25786009)(7736002)(66066001)(54906003)(86362001)(575784001)(8936002)(72206003)(3660700001)(6512007)(110136005)(14454004)(5660300001)(5250100002)(478600001)(102836004)(106356001)(8676002)(81166006)(6486002)(186003)(316002)(10290500003)(53936002)(6436002)(59450400001)(2906002)(81156014)(22906009)(217873001);DIR:OUT;SFP:1102;SCL:1;SRVR:MW2SPR01MB06;H:MW2PR2101MB1034.namprd21.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; x-microsoft-antispam-message-info: 7WN+0wkCg1ccAgNkLXlur27MohU3N+4cbkBCbO7/ee9+OyaXUIZ1uiojnJFm0e5Hq3AZjdVODQ10zuEUPzVQd1lbjm4iZWlbjTmwWD5upgfDWACmd2HJHh8OzlAvmeYzOKy35Qp103SsC/IddRbGvlKUApKDdQFCZZM7vNt9ANE= spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 79b8bcad-1807-4386-6101-08d5815601d5 X-MS-Exchange-CrossTenant-originalarrivaltime: 03 Mar 2018 22:25:07.1347 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW2SPR01MB06 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Davidlohr Bueso [ Upstream commit 2ce77d16db4240dd2e422fc0a5c26d3e2ec03446 ] Things can explode for locktorture if the user does combinations of nwriters_stress=3D0 nreaders_stress=3D0. Fix this by not assuming we always want to torture writer threads. Reported-by: Jeremy Linton Signed-off-by: Davidlohr Bueso Signed-off-by: Paul E. McKenney Reviewed-by: Jeremy Linton Tested-by: Jeremy Linton Signed-off-by: Sasha Levin --- kernel/locking/locktorture.c | 76 +++++++++++++++++++++++++---------------= ---- 1 file changed, 44 insertions(+), 32 deletions(-) diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index f24582d4dad3..6dca260eeccf 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -715,8 +715,7 @@ static void __torture_print_stats(char *page, { bool fail =3D 0; int i, n_stress; - long max =3D 0; - long min =3D statp[0].n_lock_acquired; + long max =3D 0, min =3D statp ? statp[0].n_lock_acquired : 0; long long sum =3D 0; =20 n_stress =3D write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; @@ -823,7 +822,7 @@ static void lock_torture_cleanup(void) * such, only perform the underlying torture-specific cleanups, * and avoid anything related to locktorture. */ - if (!cxt.lwsa) + if (!cxt.lwsa && !cxt.lrsa) goto end; =20 if (writer_tasks) { @@ -898,6 +897,13 @@ static int __init lock_torture_init(void) firsterr =3D -EINVAL; goto unwind; } + + if (nwriters_stress =3D=3D 0 && nreaders_stress =3D=3D 0) { + pr_alert("lock-torture: must run at least one locking thread\n"); + firsterr =3D -EINVAL; + goto unwind; + } + if (cxt.cur_ops->init) cxt.cur_ops->init(); =20 @@ -921,17 +927,19 @@ static int __init lock_torture_init(void) #endif =20 /* Initialize the statistics so that each run gets its own numbers. */ + if (nwriters_stress) { + lock_is_write_held =3D 0; + cxt.lwsa =3D kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KE= RNEL); + if (cxt.lwsa =3D=3D NULL) { + VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); + firsterr =3D -ENOMEM; + goto unwind; + } =20 - lock_is_write_held =3D 0; - cxt.lwsa =3D kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KER= NEL); - if (cxt.lwsa =3D=3D NULL) { - VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); - firsterr =3D -ENOMEM; - goto unwind; - } - for (i =3D 0; i < cxt.nrealwriters_stress; i++) { - cxt.lwsa[i].n_lock_fail =3D 0; - cxt.lwsa[i].n_lock_acquired =3D 0; + for (i =3D 0; i < cxt.nrealwriters_stress; i++) { + cxt.lwsa[i].n_lock_fail =3D 0; + cxt.lwsa[i].n_lock_acquired =3D 0; + } } =20 if (cxt.cur_ops->readlock) { @@ -948,19 +956,21 @@ static int __init lock_torture_init(void) cxt.nrealreaders_stress =3D cxt.nrealwriters_stress; } =20 - lock_is_read_held =3D 0; - cxt.lrsa =3D kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KE= RNEL); - if (cxt.lrsa =3D=3D NULL) { - VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); - firsterr =3D -ENOMEM; - kfree(cxt.lwsa); - cxt.lwsa =3D NULL; - goto unwind; - } - - for (i =3D 0; i < cxt.nrealreaders_stress; i++) { - cxt.lrsa[i].n_lock_fail =3D 0; - cxt.lrsa[i].n_lock_acquired =3D 0; + if (nreaders_stress) { + lock_is_read_held =3D 0; + cxt.lrsa =3D kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_K= ERNEL); + if (cxt.lrsa =3D=3D NULL) { + VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); + firsterr =3D -ENOMEM; + kfree(cxt.lwsa); + cxt.lwsa =3D NULL; + goto unwind; + } + + for (i =3D 0; i < cxt.nrealreaders_stress; i++) { + cxt.lrsa[i].n_lock_fail =3D 0; + cxt.lrsa[i].n_lock_acquired =3D 0; + } } } =20 @@ -990,12 +1000,14 @@ static int __init lock_torture_init(void) goto unwind; } =20 - writer_tasks =3D kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]= ), - GFP_KERNEL); - if (writer_tasks =3D=3D NULL) { - VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); - firsterr =3D -ENOMEM; - goto unwind; + if (nwriters_stress) { + writer_tasks =3D kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0= ]), + GFP_KERNEL); + if (writer_tasks =3D=3D NULL) { + VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); + firsterr =3D -ENOMEM; + goto unwind; + } } =20 if (cxt.cur_ops->readlock) { --=20 2.14.1