From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1redHo-0008Qq-UW for mharc-qemu-trivial@gnu.org; Mon, 26 Feb 2024 10:53:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1redHk-0008Pe-Th; Mon, 26 Feb 2024 10:52:56 -0500 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1redHi-0003ao-Kr; Mon, 26 Feb 2024 10:52:56 -0500 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Tk4lJ73chz6JBTb; Mon, 26 Feb 2024 23:48:12 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 046D0140A9C; Mon, 26 Feb 2024 23:52:47 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Mon, 26 Feb 2024 15:52:46 +0000 Date: Mon, 26 Feb 2024 15:52:45 +0000 From: Jonathan Cameron To: Zhao Liu CC: Markus Armbruster , Fan Ni , Laurent Vivier , Alistair Francis , "Edgar E . Iglesias" , Peter Maydell , "Michael S . Tsirkin" , Marcel Apfelbaum , "Alex Williamson" , "=?ISO-8859-1?Q?C=E9dric?= Le Goater" , Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= , , , , Zhao Liu Subject: Re: [PATCH 1/6] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in cxl_fixed_memory_window_config() Message-ID: <20240226155245.00004a88@Huawei.com> In-Reply-To: References: <20240221094317.994454-1-zhao1.liu@linux.intel.com> <20240221094317.994454-2-zhao1.liu@linux.intel.com> <878r3evyth.fsf@pond.sub.org> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100002.china.huawei.com (7.191.160.241) To lhrpeml500005.china.huawei.com (7.191.163.240) Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-trivial@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Feb 2024 15:52:59 -0000 On Wed, 21 Feb 2024 23:04:23 +0800 Zhao Liu wrote: > On Wed, Feb 21, 2024 at 12:31:06PM +0100, Markus Armbruster wrote: > > Date: Wed, 21 Feb 2024 12:31:06 +0100 > > From: Markus Armbruster > > Subject: Re: [PATCH 1/6] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in > > cxl_fixed_memory_window_config() > > > > Zhao Liu writes: > > > > > From: Zhao Liu > > > > > > As the comment in qapi/error, dereferencing @errp requires > > > ERRP_GUARD(): > > > > > > * = Why, when and how to use ERRP_GUARD() = > > > * > > > * Without ERRP_GUARD(), use of the @errp parameter is restricted: > > > * - It must not be dereferenced, because it may be null. > > > * - It should not be passed to error_prepend() or > > > * error_append_hint(), because that doesn't work with &error_fatal. > > > * ERRP_GUARD() lifts these restrictions. > > > * > > > * To use ERRP_GUARD(), add it right at the beginning of the function. > > > * @errp can then be used without worrying about the argument being > > > * NULL or &error_fatal. > > > * > > > * Using it when it's not needed is safe, but please avoid cluttering > > > * the source with useless code. > > > > > > Currently, since machine_set_cfmw() - the caller of > > > cxl_fixed_memory_window_config() - doesn't get the NULL errp parameter > > > as the "set" method of object property, cxl_fixed_memory_window_config() > > > doesn't trigger the dereference issue. > > > > > > To follow the requirement of errp, add missing ERRP_GUARD() in > > > cxl_fixed_memory_window_config(). > > > > > > Suggested-by: Markus Armbruster > > > Signed-off-by: Zhao Liu > > > --- > > > Suggested by credit: > > > Markus: Referred his explanation about ERRP_GUARD(). > > > --- > > > hw/cxl/cxl-host.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/hw/cxl/cxl-host.c b/hw/cxl/cxl-host.c > > > index 2aa776c79c74..c5f5fcfd64d0 100644 > > > --- a/hw/cxl/cxl-host.c > > > +++ b/hw/cxl/cxl-host.c > > > @@ -26,6 +26,7 @@ static void cxl_fixed_memory_window_config(CXLState *cxl_state, > > > CXLFixedMemoryWindowOptions *object, > > > Error **errp) > > > { > > > + ERRP_GUARD(); > > > g_autofree CXLFixedWindow *fw = g_malloc0(sizeof(*fw)); > > > strList *target; > > > int i; > > > > The dereferences are > > > > fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp); > > if (*errp) { > > return; > > } > > > > and > > > > fw->enc_int_gran = > > cxl_interleave_granularity_enc(object->interleave_granularity, > > errp); > > if (*errp) { > > return; > > } > > > > We check *errp, because neither function returns a suitable error code. > > > > Reviewed-by: Markus Armbruster > > > > Thanks! I'll attach your description to the commit message. Thanks for the explanation in the commit message and to Markus for the cases it affected. Acked-by: Jonathan Cameron > > Regards, > Zhao > From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by 2002:a17:906:e92:b0:a3e:79c1:d636 with SMTP id p18csp2140028ejf; Mon, 26 Feb 2024 07:53:25 -0800 (PST) X-Forwarded-Encrypted: i=2; AJvYcCXqtw514or3dDmqEbz6q4C5lZ3hKRvj/sWA8yh5tnMXam8o0YMNGhrlF9ZsESG54oJMJkSnckbl6ARuO9VP4fQ39tou7VIf X-Google-Smtp-Source: AGHT+IG3Rk88Z4i+II/d2Wyd+JZJtZ+mmLO3FI79SMK7ZLdbd2kITXYN5YqoUpajhJTzimLy+p4i X-Received: by 2002:a05:620a:5645:b0:787:90a4:7694 with SMTP id vw5-20020a05620a564500b0078790a47694mr8348296qkn.61.1708962805543; Mon, 26 Feb 2024 07:53:25 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1708962805; cv=none; d=google.com; s=arc-20160816; b=X8QcWeRTTbsm5dZcKl9wua/qkNCkTKODa0T0PMdsdOB+vFitSQjZM3eP8iOe9+Wo2D gR9xGDbHg1APAmg6Av4EUX/m94R9ATkfDUC/++KG8Tp6uwUs8gaSaIsakJ7amPv2Ioj/ v9UPTjKGfg1XMzOt9mhDzU55mRFbaKepFZF3WcbmB6uB8+sSyVAYU9GFPyrMqva4FmWd Y2vZOrsuUByc6MFnd0hlas/tPOn0jpnUBEBkKyI1vd9oIgrezSib5CCITk+b080kVFes 7e8iYBWpE3dpQtMcK2t9QV4LESiuFfHUY+uVnq1AKJhXQm6eBlIau+adha/uiyx4Feps sy7g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:from:reply-to:list-subscribe:list-help:list-post :list-archive:list-unsubscribe:list-id:precedence :content-transfer-encoding:mime-version:organization:references :in-reply-to:message-id:subject:cc:to:date; bh=JoGHBVhrF2k2h1YyWAFWxo34csvXgz7vGuhIvApF1Fk=; fh=37J9MutlcBgsQwZkIUG4fQHW+H9Zl6PxtJqQRC0HTfQ=; b=TtLmUZdjQjft5ixQE0ZrZjDmry0vWKv/7UevJ5ODGS5iWI5Ka6fGQQpQuxg6eZbsi7 0CjWMEIGpJVmlut7zeQ2nbUnRaSEt3kf7aRnAnBWmdEiCiZnw+KqF6jW+wUdBfT89ljP hB88vk6KDqxHpnMtKUoi+5xHywdWruiS7osBf4Q6vT+kMU7RZ+EeO2P0UKx2am9zHE8M yc3PSnR4ODs+0I45U/X6Ijm/9ZKi7qxvzaxDcUEASmjLJmh+JOikKC2S9Y8jQiIN6RoP QVz/Sexr5W0/Rr3HC7UdZxXDNH59Qavn5XHGHDw+PwPPM41U3DyYx+Vljwim0GhOH3IF T1JA==; dara=google.com ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org. [209.51.188.17]) by mx.google.com with ESMTPS id q14-20020a05620a038e00b0078753bb0d36si5300726qkm.602.2024.02.26.07.53.25 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 26 Feb 2024 07:53:25 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nongnu.org Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1redHn-0008QI-6p; Mon, 26 Feb 2024 10:53:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1redHk-0008Pe-Th; Mon, 26 Feb 2024 10:52:56 -0500 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1redHi-0003ao-Kr; Mon, 26 Feb 2024 10:52:56 -0500 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Tk4lJ73chz6JBTb; Mon, 26 Feb 2024 23:48:12 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 046D0140A9C; Mon, 26 Feb 2024 23:52:47 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Mon, 26 Feb 2024 15:52:46 +0000 Date: Mon, 26 Feb 2024 15:52:45 +0000 To: Zhao Liu CC: Markus Armbruster , Fan Ni , Laurent Vivier , Alistair Francis , "Edgar E . Iglesias" , Peter Maydell , "Michael S . Tsirkin" , Marcel Apfelbaum , "Alex Williamson" , "=?ISO-8859-1?Q?C=E9dric?= Le Goater" , Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= , , , , Zhao Liu Subject: Re: [PATCH 1/6] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in cxl_fixed_memory_window_config() Message-ID: <20240226155245.00004a88@Huawei.com> In-Reply-To: References: <20240221094317.994454-1-zhao1.liu@linux.intel.com> <20240221094317.994454-2-zhao1.liu@linux.intel.com> <878r3evyth.fsf@pond.sub.org> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100002.china.huawei.com (7.191.160.241) To lhrpeml500005.china.huawei.com (7.191.163.240) Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-arm@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Jonathan Cameron From: Jonathan Cameron via Errors-To: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org Sender: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org X-TUID: HAXKL/riRHvu On Wed, 21 Feb 2024 23:04:23 +0800 Zhao Liu wrote: > On Wed, Feb 21, 2024 at 12:31:06PM +0100, Markus Armbruster wrote: > > Date: Wed, 21 Feb 2024 12:31:06 +0100 > > From: Markus Armbruster > > Subject: Re: [PATCH 1/6] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in > > cxl_fixed_memory_window_config() > > > > Zhao Liu writes: > > > > > From: Zhao Liu > > > > > > As the comment in qapi/error, dereferencing @errp requires > > > ERRP_GUARD(): > > > > > > * = Why, when and how to use ERRP_GUARD() = > > > * > > > * Without ERRP_GUARD(), use of the @errp parameter is restricted: > > > * - It must not be dereferenced, because it may be null. > > > * - It should not be passed to error_prepend() or > > > * error_append_hint(), because that doesn't work with &error_fatal. > > > * ERRP_GUARD() lifts these restrictions. > > > * > > > * To use ERRP_GUARD(), add it right at the beginning of the function. > > > * @errp can then be used without worrying about the argument being > > > * NULL or &error_fatal. > > > * > > > * Using it when it's not needed is safe, but please avoid cluttering > > > * the source with useless code. > > > > > > Currently, since machine_set_cfmw() - the caller of > > > cxl_fixed_memory_window_config() - doesn't get the NULL errp parameter > > > as the "set" method of object property, cxl_fixed_memory_window_config() > > > doesn't trigger the dereference issue. > > > > > > To follow the requirement of errp, add missing ERRP_GUARD() in > > > cxl_fixed_memory_window_config(). > > > > > > Suggested-by: Markus Armbruster > > > Signed-off-by: Zhao Liu > > > --- > > > Suggested by credit: > > > Markus: Referred his explanation about ERRP_GUARD(). > > > --- > > > hw/cxl/cxl-host.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/hw/cxl/cxl-host.c b/hw/cxl/cxl-host.c > > > index 2aa776c79c74..c5f5fcfd64d0 100644 > > > --- a/hw/cxl/cxl-host.c > > > +++ b/hw/cxl/cxl-host.c > > > @@ -26,6 +26,7 @@ static void cxl_fixed_memory_window_config(CXLState *cxl_state, > > > CXLFixedMemoryWindowOptions *object, > > > Error **errp) > > > { > > > + ERRP_GUARD(); > > > g_autofree CXLFixedWindow *fw = g_malloc0(sizeof(*fw)); > > > strList *target; > > > int i; > > > > The dereferences are > > > > fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp); > > if (*errp) { > > return; > > } > > > > and > > > > fw->enc_int_gran = > > cxl_interleave_granularity_enc(object->interleave_granularity, > > errp); > > if (*errp) { > > return; > > } > > > > We check *errp, because neither function returns a suitable error code. > > > > Reviewed-by: Markus Armbruster > > > > Thanks! I'll attach your description to the commit message. Thanks for the explanation in the commit message and to Markus for the cases it affected. Acked-by: Jonathan Cameron > > Regards, > Zhao > 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3E3A1C48BF6 for ; Mon, 26 Feb 2024 15:53:31 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1redHn-0008QP-Rs; Mon, 26 Feb 2024 10:52:59 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1redHk-0008Pe-Th; Mon, 26 Feb 2024 10:52:56 -0500 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1redHi-0003ao-Kr; Mon, 26 Feb 2024 10:52:56 -0500 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Tk4lJ73chz6JBTb; Mon, 26 Feb 2024 23:48:12 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 046D0140A9C; Mon, 26 Feb 2024 23:52:47 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Mon, 26 Feb 2024 15:52:46 +0000 Date: Mon, 26 Feb 2024 15:52:45 +0000 To: Zhao Liu CC: Markus Armbruster , Fan Ni , Laurent Vivier , Alistair Francis , "Edgar E . Iglesias" , Peter Maydell , "Michael S . Tsirkin" , Marcel Apfelbaum , "Alex Williamson" , "=?ISO-8859-1?Q?C=E9dric?= Le Goater" , Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= , , , , Zhao Liu Subject: Re: [PATCH 1/6] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in cxl_fixed_memory_window_config() Message-ID: <20240226155245.00004a88@Huawei.com> In-Reply-To: References: <20240221094317.994454-1-zhao1.liu@linux.intel.com> <20240221094317.994454-2-zhao1.liu@linux.intel.com> <878r3evyth.fsf@pond.sub.org> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100002.china.huawei.com (7.191.160.241) To lhrpeml500005.china.huawei.com (7.191.163.240) Received-SPF: pass client-ip=185.176.79.56; envelope-from=jonathan.cameron@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: Jonathan Cameron From: Jonathan Cameron via Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, 21 Feb 2024 23:04:23 +0800 Zhao Liu wrote: > On Wed, Feb 21, 2024 at 12:31:06PM +0100, Markus Armbruster wrote: > > Date: Wed, 21 Feb 2024 12:31:06 +0100 > > From: Markus Armbruster > > Subject: Re: [PATCH 1/6] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in > > cxl_fixed_memory_window_config() > > > > Zhao Liu writes: > > > > > From: Zhao Liu > > > > > > As the comment in qapi/error, dereferencing @errp requires > > > ERRP_GUARD(): > > > > > > * = Why, when and how to use ERRP_GUARD() = > > > * > > > * Without ERRP_GUARD(), use of the @errp parameter is restricted: > > > * - It must not be dereferenced, because it may be null. > > > * - It should not be passed to error_prepend() or > > > * error_append_hint(), because that doesn't work with &error_fatal. > > > * ERRP_GUARD() lifts these restrictions. > > > * > > > * To use ERRP_GUARD(), add it right at the beginning of the function. > > > * @errp can then be used without worrying about the argument being > > > * NULL or &error_fatal. > > > * > > > * Using it when it's not needed is safe, but please avoid cluttering > > > * the source with useless code. > > > > > > Currently, since machine_set_cfmw() - the caller of > > > cxl_fixed_memory_window_config() - doesn't get the NULL errp parameter > > > as the "set" method of object property, cxl_fixed_memory_window_config() > > > doesn't trigger the dereference issue. > > > > > > To follow the requirement of errp, add missing ERRP_GUARD() in > > > cxl_fixed_memory_window_config(). > > > > > > Suggested-by: Markus Armbruster > > > Signed-off-by: Zhao Liu > > > --- > > > Suggested by credit: > > > Markus: Referred his explanation about ERRP_GUARD(). > > > --- > > > hw/cxl/cxl-host.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/hw/cxl/cxl-host.c b/hw/cxl/cxl-host.c > > > index 2aa776c79c74..c5f5fcfd64d0 100644 > > > --- a/hw/cxl/cxl-host.c > > > +++ b/hw/cxl/cxl-host.c > > > @@ -26,6 +26,7 @@ static void cxl_fixed_memory_window_config(CXLState *cxl_state, > > > CXLFixedMemoryWindowOptions *object, > > > Error **errp) > > > { > > > + ERRP_GUARD(); > > > g_autofree CXLFixedWindow *fw = g_malloc0(sizeof(*fw)); > > > strList *target; > > > int i; > > > > The dereferences are > > > > fw->enc_int_ways = cxl_interleave_ways_enc(fw->num_targets, errp); > > if (*errp) { > > return; > > } > > > > and > > > > fw->enc_int_gran = > > cxl_interleave_granularity_enc(object->interleave_granularity, > > errp); > > if (*errp) { > > return; > > } > > > > We check *errp, because neither function returns a suitable error code. > > > > Reviewed-by: Markus Armbruster > > > > Thanks! I'll attach your description to the commit message. Thanks for the explanation in the commit message and to Markus for the cases it affected. Acked-by: Jonathan Cameron > > Regards, > Zhao >