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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43ED5C433EF for ; Wed, 9 Feb 2022 17:39:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230289AbiBIRj3 (ORCPT ); Wed, 9 Feb 2022 12:39:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238284AbiBIRj2 (ORCPT ); Wed, 9 Feb 2022 12:39:28 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AA1FC05CB82 for ; Wed, 9 Feb 2022 09:39:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644428371; x=1675964371; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=pcWa4vPzDFsaidBuXlyIic9God6Kqn1zS9nlAhJBeyQ=; b=lQOw4ky/xWVm7aPCjcf1AczbcNm08LrDFQ4vjaf3luV6cZG1I8JR+vXH lO8MTdv32BJwvdmJehUxWU9R3eglWmyp/9W7MkLBvlx3s3WrJaMijSPi1 N9paJ41GfvC4agCID7cNnQT4xlEVFe4LN0vWpxxqT9fIh9bqkEmIS9leR waL8tAcrV2cKUd0IPwL+vGSrhkADCBRECxJ+otLgi2snFEOGw3hJXBc71 SA0hQxJRd1QzhjunnESWR2EQosMP20ejubwwxL1c0MlSVOfwqVc6ez8d1 XOKygreoWpxUTpOqzH7bR8ON4WFvZVONK9EftzrXspz1KIuRuLOe0Rrkj w==; X-IronPort-AV: E=McAfee;i="6200,9189,10252"; a="335676634" X-IronPort-AV: E=Sophos;i="5.88,356,1635231600"; d="scan'208";a="335676634" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Feb 2022 09:39:31 -0800 X-IronPort-AV: E=Sophos;i="5.88,356,1635231600"; d="scan'208";a="526084149" Received: from dgarg1-mobl.amr.corp.intel.com (HELO intel.com) ([10.252.131.253]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Feb 2022 09:39:30 -0800 Date: Wed, 9 Feb 2022 09:39:29 -0800 From: Ben Widawsky To: Dan Williams Cc: linux-cxl@vger.kernel.org Subject: Re: [PATCH] cxl/core: Fix cxl_device_lock() class detection Message-ID: <20220209173929.ivkvmf6nr4omrqwc@intel.com> References: <164439225406.2941117.3927102269866914339.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <164439225406.2941117.3927102269866914339.stgit@dwillia2-desk3.amr.corp.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On 22-02-08 23:37:34, Dan Williams wrote: > If cxl_device_lock() is used on a non-CXL device the expectation is that > the lock class will fall back to CXL_ANON_LOCK. Instead it crashes when > trying to determine if the device is a 'decoder'. Specifically when the > device has a NULL type pointer. Just check for NULL before > de-referencing ->release. > > Fixes: 3c5b90395525 ("cxl: Prove CXL locking") > Reported-by: Ben Widawsky > Signed-off-by: Dan Williams Reviewed-by: Ben Widawsky > --- > drivers/cxl/core/port.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index 9b4bbd51fbaa..d29eb2abdbc2 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -284,7 +284,7 @@ EXPORT_SYMBOL_NS_GPL(is_root_decoder, CXL); > > bool is_cxl_decoder(struct device *dev) > { > - return dev->type->release == cxl_decoder_release; > + return dev->type && dev->type->release == cxl_decoder_release; > } > EXPORT_SYMBOL_NS_GPL(is_cxl_decoder, CXL); > >