From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 779FBC04E53 for ; Wed, 15 May 2019 11:51:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48AA52053B for ; Wed, 15 May 2019 11:51:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557921068; bh=zFzl0zPOvD4rreSA638Dd7GW+rQE7WMGAsueLnw3frY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sZgH0JviUYRpd9BIJpXIyvJDJXwkkAYaGI+cS6E6ZHfOejYsAWwd94xLHAlGYHdHm cUmr2Q4LHPhsHS02RdFL4v6GLuCxrWf7G7htZry3xFJUfdnRhD+QfUsrPXQBFC0MeB nQVxCNVsBE1Ko45CY1ETLupa9uANgbJ/n2VD62r4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731345AbfEOLVs (ORCPT ); Wed, 15 May 2019 07:21:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:59762 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731342AbfEOLVs (ORCPT ); Wed, 15 May 2019 07:21:48 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3255820843; Wed, 15 May 2019 11:21:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557919306; bh=zFzl0zPOvD4rreSA638Dd7GW+rQE7WMGAsueLnw3frY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hOOa2kIFiWbOFJPI7qY/Ywiq+eakKP8WwxfzOFFtVVai/I7ccZ9HuWBXcycdsat1y YPxG4J9N7f7ap0hh8tAJViFOmLk96uQvTzR/y3teWEszXkwBwDC1jbyF/EjA8im8Cz jyuRJSxlsTVbWERz6ORgRjrnm2SMFgezxOKwlHT8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Schwidefsky , Sasha Levin Subject: [PATCH 4.19 025/113] s390/3270: fix lockdep false positive on view->lock Date: Wed, 15 May 2019 12:55:16 +0200 Message-Id: <20190515090655.405735510@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190515090652.640988966@linuxfoundation.org> References: <20190515090652.640988966@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 5712f3301a12c0c3de9cc423484496b0464f2faf ] The spinlock in the raw3270_view structure is used by con3270, tty3270 and fs3270 in different ways. For con3270 the lock can be acquired in irq context, for tty3270 and fs3270 the highest context is bh. Lockdep sees the view->lock as a single class and if the 3270 driver is used for the console the following message is generated: WARNING: inconsistent lock state 5.1.0-rc3-05157-g5c168033979d #12 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes: (____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330 Introduce a lockdep subclass for the view lock to distinguish bh from irq locks. Signed-off-by: Martin Schwidefsky Signed-off-by: Sasha Levin --- drivers/s390/char/con3270.c | 2 +- drivers/s390/char/fs3270.c | 3 ++- drivers/s390/char/raw3270.c | 3 ++- drivers/s390/char/raw3270.h | 4 +++- drivers/s390/char/tty3270.c | 3 ++- 5 files changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/s390/char/con3270.c b/drivers/s390/char/con3270.c index fd2146bcc0add..e17364e13d2f7 100644 --- a/drivers/s390/char/con3270.c +++ b/drivers/s390/char/con3270.c @@ -629,7 +629,7 @@ con3270_init(void) (void (*)(unsigned long)) con3270_read_tasklet, (unsigned long) condev->read); - raw3270_add_view(&condev->view, &con3270_fn, 1); + raw3270_add_view(&condev->view, &con3270_fn, 1, RAW3270_VIEW_LOCK_IRQ); INIT_LIST_HEAD(&condev->freemem); for (i = 0; i < CON3270_STRING_PAGES; i++) { diff --git a/drivers/s390/char/fs3270.c b/drivers/s390/char/fs3270.c index 16a4e8528bbc3..2f9905ee047cd 100644 --- a/drivers/s390/char/fs3270.c +++ b/drivers/s390/char/fs3270.c @@ -463,7 +463,8 @@ fs3270_open(struct inode *inode, struct file *filp) init_waitqueue_head(&fp->wait); fp->fs_pid = get_pid(task_pid(current)); - rc = raw3270_add_view(&fp->view, &fs3270_fn, minor); + rc = raw3270_add_view(&fp->view, &fs3270_fn, minor, + RAW3270_VIEW_LOCK_BH); if (rc) { fs3270_free_view(&fp->view); goto out; diff --git a/drivers/s390/char/raw3270.c b/drivers/s390/char/raw3270.c index f8cd2935fbfd4..63a41b1687610 100644 --- a/drivers/s390/char/raw3270.c +++ b/drivers/s390/char/raw3270.c @@ -920,7 +920,7 @@ raw3270_deactivate_view(struct raw3270_view *view) * Add view to device with minor "minor". */ int -raw3270_add_view(struct raw3270_view *view, struct raw3270_fn *fn, int minor) +raw3270_add_view(struct raw3270_view *view, struct raw3270_fn *fn, int minor, int subclass) { unsigned long flags; struct raw3270 *rp; @@ -942,6 +942,7 @@ raw3270_add_view(struct raw3270_view *view, struct raw3270_fn *fn, int minor) view->cols = rp->cols; view->ascebc = rp->ascebc; spin_lock_init(&view->lock); + lockdep_set_subclass(&view->lock, subclass); list_add(&view->list, &rp->view_list); rc = 0; spin_unlock_irqrestore(get_ccwdev_lock(rp->cdev), flags); diff --git a/drivers/s390/char/raw3270.h b/drivers/s390/char/raw3270.h index 114ca7cbf8897..3afaa35f73513 100644 --- a/drivers/s390/char/raw3270.h +++ b/drivers/s390/char/raw3270.h @@ -150,6 +150,8 @@ struct raw3270_fn { struct raw3270_view { struct list_head list; spinlock_t lock; +#define RAW3270_VIEW_LOCK_IRQ 0 +#define RAW3270_VIEW_LOCK_BH 1 atomic_t ref_count; struct raw3270 *dev; struct raw3270_fn *fn; @@ -158,7 +160,7 @@ struct raw3270_view { unsigned char *ascebc; /* ascii -> ebcdic table */ }; -int raw3270_add_view(struct raw3270_view *, struct raw3270_fn *, int); +int raw3270_add_view(struct raw3270_view *, struct raw3270_fn *, int, int); int raw3270_activate_view(struct raw3270_view *); void raw3270_del_view(struct raw3270_view *); void raw3270_deactivate_view(struct raw3270_view *); diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c index 5b8af27822828..81067f5bb178e 100644 --- a/drivers/s390/char/tty3270.c +++ b/drivers/s390/char/tty3270.c @@ -980,7 +980,8 @@ static int tty3270_install(struct tty_driver *driver, struct tty_struct *tty) return PTR_ERR(tp); rc = raw3270_add_view(&tp->view, &tty3270_fn, - tty->index + RAW3270_FIRSTMINOR); + tty->index + RAW3270_FIRSTMINOR, + RAW3270_VIEW_LOCK_BH); if (rc) { tty3270_free_view(tp); return rc; -- 2.20.1