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[209.132.180.67]) by mx.google.com with ESMTP id c19si1488133ejs.171.2019.10.21.07.22.52; Mon, 21 Oct 2019 07:23:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=LAzG96Pu; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729410AbfJUOVZ (ORCPT + 99 others); Mon, 21 Oct 2019 10:21:25 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:27390 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726289AbfJUOVY (ORCPT ); Mon, 21 Oct 2019 10:21:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571667683; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EXrHWhiwOCJRToyN96S6wFZkmcZIF7RksXCsxcL0ZHo=; b=LAzG96Pu5+GWLUmPoWbifFXIkOY7EbZn7FOmgPtZqPMZ84k6dgU7HfYGHveyxO7TaFhZcd ZyjYx76oij2ox6B0QGzy4OuzIDGWlCxwdDz7DtShkOQAL5alp10A4/1jbM3n7zsPO+lOpf apatIApCzzxtKusWaHYluqE2Xr02ihw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-201-QXBWfOh3NLGuZvs4eNiVCA-1; Mon, 21 Oct 2019 10:21:17 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B1B1C1005500; Mon, 21 Oct 2019 14:21:15 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.44]) by smtp.corp.redhat.com (Postfix) with SMTP id 1AB2610018FF; Mon, 21 Oct 2019 14:21:12 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 21 Oct 2019 16:21:14 +0200 (CEST) Date: Mon, 21 Oct 2019 16:21:11 +0200 From: Oleg Nesterov To: Tejun Heo , Li Zefan , Johannes Weiner Cc: akpm@linux-foundation.org, arnd@arndb.de, christian@brauner.io, deepa.kernel@gmail.com, ebiederm@xmission.com, elver@google.com, guro@fb.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: cgroup_enable_task_cg_lists && PF_EXITING (Was: KCSAN: data-race in exit_signals / prepare_signal) Message-ID: <20191021142111.GB1339@redhat.com> References: <0000000000003b1e8005956939f1@google.com> MIME-Version: 1.0 In-Reply-To: <0000000000003b1e8005956939f1@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: QXBWfOh3NLGuZvs4eNiVCA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org could you explain the usage of siglock/PF_EXITING in cgroup_enable_task_cg_lists() ? PF_EXITING is protected by cgroup_threadgroup_rwsem, not by sighand->siglock. Oleg.