From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30798 invoked by alias); 28 Mar 2016 09:45:59 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 30787 invoked by uid 89); 28 Mar 2016 09:45:58 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.6 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.2 spammy=2016-03-28, regressions, H*Ad:U*thomas, Hx-languages-length:2489 X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 28 Mar 2016 09:45:48 +0000 Received: from svr-orw-fem-06.mgc.mentorg.com ([147.34.97.120]) by relay1.mentorg.com with esmtp id 1akTk0-0001wo-03 from ChungLin_Tang@mentor.com ; Mon, 28 Mar 2016 02:45:44 -0700 Received: from [0.0.0.0] (147.34.91.1) by SVR-ORW-FEM-06.mgc.mentorg.com (147.34.97.120) with Microsoft SMTP Server id 14.3.224.2; Mon, 28 Mar 2016 02:45:43 -0700 From: Chung-Lin Tang Subject: [PATCH, libgomp] Fix deadlock in acc_set_device_type To: gcc-patches , Jakub Jelinek CC: Thomas Schwinge Message-ID: <56F8FD46.1060400@codesourcery.com> Date: Mon, 28 Mar 2016 11:18:00 -0000 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.7.1 MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="------------060702060202060702050502" X-IsSubscribed: yes X-SW-Source: 2016-03/txt/msg01457.txt.bz2 --------------060702060202060702050502 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-length: 1222 Hi Jakub, there's a path for deadlock on acc_device_lock when going through the acc_set_device_type() OpenACC library function. Basically, the gomp_init_targets_once() function should not be called with that held. The attached patch moves it appropriately. Also in this patch, there are several cases in acc_* functions where gomp_init_targets_once() is guarded by a test of !cached_base_dev. Since that function already uses pthread_once() to call gomp_target_init(), and technically cached_base_dev is protected by acc_device_lock, the cleanest way should be to simply drop those "if(!cached_base_dev)" tests. Tested libgomp without regressions on an nvptx offloaded system, is this okay for trunk? Thanks, Chung-Lin 2016-03-28 Chung-Lin Tang * oacc-init.c (acc_init): Remove !cached_base_dev condition on call to gomp_init_targets_once(). (acc_set_device_type): Remove !cached_base_dev condition on call to gomp_init_targets_once(), move call to before acc_device_lock acquire, to avoid deadlock. (acc_get_device_num): Remove !cached_base_dev condition on call to gomp_init_targets_once(). (acc_set_device_num): Likewise. --------------060702060202060702050502 Content-Type: text/plain; charset="UTF-8"; x-mac-type=0; x-mac-creator=0; name="a.diff" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="a.diff" Content-length: 1835 SW5kZXg6IG9hY2MtaW5pdC5jCj09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0t IG9hY2MtaW5pdC5jCShyZXZpc2lvbiAyMzQ1MDIpCisrKyBvYWNjLWluaXQu Ywkod29ya2luZyBjb3B5KQpAQCAtNDMzLDggKzQzMyw3IEBAIGdvYWNjX2F0 dGFjaF9ob3N0X3RocmVhZF90b19kZXZpY2UgKGludCBvcmQpCiB2b2lkCiBh Y2NfaW5pdCAoYWNjX2RldmljZV90IGQpCiB7Ci0gIGlmICghY2FjaGVkX2Jh c2VfZGV2KQotICAgIGdvbXBfaW5pdF90YXJnZXRzX29uY2UgKCk7CisgIGdv bXBfaW5pdF90YXJnZXRzX29uY2UgKCk7CiAKICAgZ29tcF9tdXRleF9sb2Nr ICgmYWNjX2RldmljZV9sb2NrKTsKIApAQCAtNDk4LDExICs0OTcsMTAgQEAg YWNjX3NldF9kZXZpY2VfdHlwZSAoYWNjX2RldmljZV90IGQpCiAgIHN0cnVj dCBnb21wX2RldmljZV9kZXNjciAqYmFzZV9kZXYsICphY2NfZGV2OwogICBz dHJ1Y3QgZ29hY2NfdGhyZWFkICp0aHIgPSBnb2FjY190aHJlYWQgKCk7CiAK KyAgZ29tcF9pbml0X3RhcmdldHNfb25jZSAoKTsKKwogICBnb21wX211dGV4 X2xvY2sgKCZhY2NfZGV2aWNlX2xvY2spOwogCi0gIGlmICghY2FjaGVkX2Jh c2VfZGV2KQotICAgIGdvbXBfaW5pdF90YXJnZXRzX29uY2UgKCk7Ci0KICAg Y2FjaGVkX2Jhc2VfZGV2ID0gYmFzZV9kZXYgPSByZXNvbHZlX2RldmljZSAo ZCwgdHJ1ZSk7CiAgIGFjY19kZXYgPSAmYmFzZV9kZXZbZ29hY2NfZGV2aWNl X251bV07CiAKQEAgLTU2Myw4ICs1NjEsNyBAQCBhY2NfZ2V0X2RldmljZV9u dW0gKGFjY19kZXZpY2VfdCBkKQogICBpZiAoZCA+PSBfQUNDX2RldmljZV9o d20pCiAgICAgZ29tcF9mYXRhbCAoInVua25vd24gZGV2aWNlIHR5cGUgJXUi LCAodW5zaWduZWQpIGQpOwogCi0gIGlmICghY2FjaGVkX2Jhc2VfZGV2KQot ICAgIGdvbXBfaW5pdF90YXJnZXRzX29uY2UgKCk7CisgIGdvbXBfaW5pdF90 YXJnZXRzX29uY2UgKCk7CiAKICAgZ29tcF9tdXRleF9sb2NrICgmYWNjX2Rl dmljZV9sb2NrKTsKICAgZGV2ID0gcmVzb2x2ZV9kZXZpY2UgKGQsIHRydWUp OwpAQCAtNTg0LDggKzU4MSw3IEBAIGFjY19zZXRfZGV2aWNlX251bSAoaW50 IG9yZCwgYWNjX2RldmljZV90IGQpCiAgIHN0cnVjdCBnb21wX2RldmljZV9k ZXNjciAqYmFzZV9kZXYsICphY2NfZGV2OwogICBpbnQgbnVtX2RldmljZXM7 CiAKLSAgaWYgKCFjYWNoZWRfYmFzZV9kZXYpCi0gICAgZ29tcF9pbml0X3Rh cmdldHNfb25jZSAoKTsKKyAgZ29tcF9pbml0X3RhcmdldHNfb25jZSAoKTsK IAogICBpZiAob3JkIDwgMCkKICAgICBvcmQgPSBnb2FjY19kZXZpY2VfbnVt Owo= --------------060702060202060702050502--