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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 4E477C4363A for ; Thu, 29 Oct 2020 19:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5B592075E for ; Thu, 29 Oct 2020 19:09:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603998594; bh=Pt6WFzMLYTX0xhEREmX9YvFBIhL4r4F+3MKqRLIaqbQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=qEHw+L9cGhvFn9TPPUNv6H51W0Es8FOspyOEBSEYpiFaDSCZZCQVODVaomh7r6p6H QLuWxmgjAPS30KdPeoQrFxwQYYThIsxRznnhatdlAvrsOxHngBv7SYyLx1eA5Vev6d ZblPM+aQ8YODEKpkpz9BkDKuCUC/7rPALx0rnPP0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726112AbgJ2TJw (ORCPT ); Thu, 29 Oct 2020 15:09:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:44090 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725791AbgJ2TJf (ORCPT ); Thu, 29 Oct 2020 15:09:35 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 B730020756; Thu, 29 Oct 2020 19:09:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603998563; bh=Pt6WFzMLYTX0xhEREmX9YvFBIhL4r4F+3MKqRLIaqbQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Uk6TyvBZKB9y7WjP0zclRkEjbT/gg4W0oGC0Me1DwJERMBFa8/UaqvyCm0d2R8LLY 7+NxOIT4l25TEkcWGM9v581sCaVX2tcENARVb3QwLW8ot3qEOfUhC1A1dkY5zjc4UQ 26j1wSDsT5SkfWUi9XlrSzudIcC8wrbRh+EGtj6Q= Date: Thu, 29 Oct 2020 20:10:11 +0100 From: Greg KH To: Mathieu Poirier Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] coresight: cti: Initialize dynamic sysfs attributes Message-ID: <20201029191011.GA826513@kroah.com> References: <20201029164559.1268531-1-mathieu.poirier@linaro.org> <20201029164559.1268531-2-mathieu.poirier@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201029164559.1268531-2-mathieu.poirier@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 29, 2020 at 10:45:58AM -0600, Mathieu Poirier wrote: > From: Suzuki K Poulose > > With LOCKDEP enabled, CTI driver triggers the following splat due > to uninitialized lock class for dynamically allocated attribute > objects. > > [ 5.372901] coresight etm0: CPU0: ETM v4.0 initialized > [ 5.376694] coresight etm1: CPU1: ETM v4.0 initialized > [ 5.380785] coresight etm2: CPU2: ETM v4.0 initialized > [ 5.385851] coresight etm3: CPU3: ETM v4.0 initialized > [ 5.389808] BUG: key ffff00000564a798 has not been registered! > [ 5.392456] ------------[ cut here ]------------ > [ 5.398195] DEBUG_LOCKS_WARN_ON(1) > [ 5.398233] WARNING: CPU: 1 PID: 32 at kernel/locking/lockdep.c:4623 lockdep_init_map_waits+0x14c/0x260 > [ 5.406149] Modules linked in: > [ 5.415411] CPU: 1 PID: 32 Comm: kworker/1:1 Not tainted 5.9.0-12034-gbbe85027ce80 #51 > [ 5.418553] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) > [ 5.426453] Workqueue: events amba_deferred_retry_func > [ 5.433299] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--) > [ 5.438252] pc : lockdep_init_map_waits+0x14c/0x260 > [ 5.444410] lr : lockdep_init_map_waits+0x14c/0x260 > [ 5.449007] sp : ffff800012bbb720 > ... > > [ 5.531561] Call trace: > [ 5.536847] lockdep_init_map_waits+0x14c/0x260 > [ 5.539027] __kernfs_create_file+0xa8/0x1c8 > [ 5.543539] sysfs_add_file_mode_ns+0xd0/0x208 > [ 5.548054] internal_create_group+0x118/0x3c8 > [ 5.552307] internal_create_groups+0x58/0xb8 > [ 5.556733] sysfs_create_groups+0x2c/0x38 > [ 5.561160] device_add+0x2d8/0x768 > [ 5.565148] device_register+0x28/0x38 > [ 5.568537] coresight_register+0xf8/0x320 > [ 5.572358] cti_probe+0x1b0/0x3f0 > > ... > > Fix this by initializing the attributes when they are allocated. > > Fixes: 3c5597e39812 ("coresight: cti: Add connection information to sysfs") > Reported-by: Leo Yan > Tested-by: Leo Yan > Cc: Mike Leach > Cc: Mathieu Poirier > Signed-off-by: Suzuki K Poulose > Signed-off-by: Mathieu Poirier > --- > drivers/hwtracing/coresight/coresight-cti-sysfs.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c > index 392757f3a019..7ff7e7780bbf 100644 > --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c > @@ -1065,6 +1065,13 @@ static int cti_create_con_sysfs_attr(struct device *dev, > } > eattr->var = con; > con->con_attrs[attr_idx] = &eattr->attr.attr; > + /* > + * Initialize the dynamically allocated attribute > + * to avoid LOCKDEP splat. See include/linux/sysfs.h > + * for more details. > + */ > + sysfs_attr_init(con->con_attrs[attr_idx]); > + > return 0; > } Should go to stable kernels too, as the patch this fixes is in 5.7. I'll add the stable tag here, but feel free to do it yourself next time :) thanks, greg k-h