From patchwork Thu Oct 10 06:19:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 1174321 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="qdBc0B/l"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46pgsl6yV3z9sPW for ; Thu, 10 Oct 2019 17:19:39 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732897AbfJJGT2 (ORCPT ); Thu, 10 Oct 2019 02:19:28 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:9976 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727218AbfJJGT2 (ORCPT ); Thu, 10 Oct 2019 02:19:28 -0400 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id x9A6AE57014404 for ; Wed, 9 Oct 2019 23:19:27 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=s6eyAOhaBTbzLObZLe6B53V9ygLx91hA9w5VlVF+Gg4=; b=qdBc0B/lFm9WTk8wnmdA/F6tqTpvpC2EL4tjVdr8VPq5NO/zT2bbgWTu6IP1nLrA+3w8 ETFRYAGFqNew3l1fucQnFfO2s+D9/2Sb6+KnB/ji8X0VBj7n5k3kQFha4Kn4mMWxQJqi WLoAFg4hIfM9g4AuO8q71NAscqmlua5UntM= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2vhnsja484-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 09 Oct 2019 23:19:27 -0700 Received: from 2401:db00:30:6007:face:0:1:0 (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Wed, 9 Oct 2019 23:19:25 -0700 Received: by devbig006.ftw2.facebook.com (Postfix, from userid 4523) id EF1F662E3559; Wed, 9 Oct 2019 23:19:23 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Song Liu Smtp-Origin-Hostname: devbig006.ftw2.facebook.com To: , , CC: , Song Liu , , Peter Zijlstra , Alexei Starovoitov , Daniel Borkmann , Tejun Heo Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf-next 1/2] sched: introduce this_rq_is_locked() Date: Wed, 9 Oct 2019 23:19:15 -0700 Message-ID: <20191010061916.198761-2-songliubraving@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191010061916.198761-1-songliubraving@fb.com> References: <20191010061916.198761-1-songliubraving@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,1.0.8 definitions=2019-10-10_03:2019-10-08,2019-10-10 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 suspectscore=0 adultscore=0 mlxlogscore=999 impostorscore=0 priorityscore=1501 spamscore=0 lowpriorityscore=0 malwarescore=0 phishscore=0 bulkscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1908290000 definitions=main-1910100058 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org this_rq_is_locked() is introduced to check whether current CPU is holding rq_lock(). This will be used in bpf/stackmap.c to decide whether is safe to call up_read(), which may call rq_lock() for the same CPU. Fixes: commit 615755a77b24 ("bpf: extend stackmap to save binary_build_id+offset instead of address") Cc: stable@vger.kernel.org # v4.17+ Cc: Peter Zijlstra Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: Tejun Heo Signed-off-by: Song Liu --- include/linux/sched.h | 1 + kernel/sched/core.c | 8 ++++++++ 2 files changed, 9 insertions(+) -- 2.17.1 diff --git a/include/linux/sched.h b/include/linux/sched.h index 2c2e56bd8913..fb0fcbd1b6f6 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1995,4 +1995,5 @@ int sched_trace_rq_cpu(struct rq *rq); const struct cpumask *sched_trace_rd_span(struct root_domain *rd); +bool this_rq_is_locked(void); #endif diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 7880f4f64d0e..577cbe7c05fc 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -138,6 +138,14 @@ struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) } } +bool this_rq_is_locked(void) +{ + struct rq *rq; + + rq = this_rq(); + return raw_spin_is_locked(&rq->lock); +} + /* * RQ-clock updating methods: */