From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1redW3-0006Uq-MC for mharc-qemu-trivial@gnu.org; Mon, 26 Feb 2024 11:07:45 -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 1redVo-0006Kh-L8; Mon, 26 Feb 2024 11:07:29 -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 1redVg-0005xM-OL; Mon, 26 Feb 2024 11:07:26 -0500 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Tk54l1vTTz67PjK; Tue, 27 Feb 2024 00:03:19 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 9CDB7140A35; Tue, 27 Feb 2024 00:07:02 +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 16:07:02 +0000 Date: Mon, 26 Feb 2024 16:07:00 +0000 From: Jonathan Cameron To: Zhao Liu CC: 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?= , Markus Armbruster , Paolo Bonzini , Michael Tokarev , , , , Zhao Liu Subject: Re: [PATCH v2 1/7] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in cxl_fixed_memory_window_config() Message-ID: <20240226160700.00007286@Huawei.com> In-Reply-To: <20240223085653.1255438-2-zhao1.liu@linux.intel.com> References: <20240223085653.1255438-1-zhao1.liu@linux.intel.com> <20240223085653.1255438-2-zhao1.liu@linux.intel.com> 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: lhrpeml500002.china.huawei.com (7.191.160.78) 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 16:07:41 -0000 On Fri, 23 Feb 2024 16:56:47 +0800 Zhao Liu wrote: > 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. > ... > * 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. > > But in cxl_fixed_memory_window_config(), @errp is dereferenced in 2 > places without ERRP_GUARD(): > > 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; > } > > For the above 2 places, we check "*errp", because neither function > returns a suitable error code. And 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() hasn't triggered the bug that > dereferencing the NULL @errp. > > 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 > Reviewed-by: Markus Armbruster Acked-by: Jonathan Cameron > --- > Suggested by credit: > Markus: Referred his explanation about ERRP_GUARD(). > --- > v2: > * Add the @errp dereference code in commit message to make review > easier. (Markus) > --- > 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; From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by 2002:a17:906:e92:b0:a3e:79c1:d636 with SMTP id p18csp2151340ejf; Mon, 26 Feb 2024 08:09:44 -0800 (PST) X-Forwarded-Encrypted: i=2; AJvYcCVtggsIDLJD8LE4HjULufRlaiG6sujY9HGCzqGTwK6QvQnWpijCuOP/y28r3xTP0rPUxGoR4hGOVA+8WJXzxtOyvToqerM7 X-Google-Smtp-Source: AGHT+IGBbT4DEnlAFJy+Qk/nIZIB3KM14IjG68Tw6502SXMweOK4pvPy2V/MU1Os5cxuI6F0CWgA X-Received: by 2002:a05:6214:33c3:b0:68f:eed7:f234 with SMTP id mw3-20020a05621433c300b0068feed7f234mr10320072qvb.4.1708963784683; Mon, 26 Feb 2024 08:09:44 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1708963784; cv=none; d=google.com; s=arc-20160816; b=ncbbSJo3ltm1f63T7ECEWKGcu05SWD5feVracGLVJs9jWjCwq7IFFttRVMm9L+18qC LIUDc7Uu15YRHZvcjT0AVsjqPs/091EQR6D0asJ5Og/1UzXGugcdt0Szf8IpNdkSEr/+ oMcFQngJ1lBikIoqhykljwu8VAXPynPionw0mwM/gmB5wFC4HPw2Wd0NaDDNm6l1oxht 7HzsCszhNm3N7HZWwAOs9nNzclJJVy4Q+aQvnkYpuOZaCqIWnAEVRY6eniTqgU9iMTFh sk1Ymn/TDXLpquwEycm3v2D8IOoGyh8o/aQMb5UlaXjXNInWM/jezGDP8hP84Qr84vMH RnWw== 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=4D7BjEqLobON4Vj7ob1LEATj85dO/HPZWPaIfNrr+Lw=; fh=0rpLpaKs6ZjOVG7+8ukNE3SVcae7cRMmSy05SLkH3qA=; b=PrqLkYl/s98cJNOZPj2yUyKa5u85R5mKd68YEWwPtjH1GMzkapl9IrUHkNS71vV6+9 i0YZo5a5dn+7V0OmbOs4C8vO+m3TCVRuRqTIv7K31woH/xyQM2iWd1H/WFF0mf/iWZn6 FKL6jjzQ4k7wraIxpqWzuRvPmivlkrqhezMYn/oDt8o4g4wZ+DAuRX3528cFCh8n+Axk MKTH24etVUVoAyZZlzC1l7XP2j2l70bjYsm23+Uc1QW6hk+eWSHBsA6TkhiN2yDZDAVB MIlVllMtG+52sL+QHel1X444RPh4gSFDMbbJwKvkfdRHHPGikvaj17S880tJde8Erj3B qDNg==; dara=google.com ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-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 q7-20020ad45747000000b0068eeeabaa8fsi5622609qvx.144.2024.02.26.08.09.44 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 26 Feb 2024 08:09:44 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-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-devel-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-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 1redWA-0006YN-LM; Mon, 26 Feb 2024 11:07:50 -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 1redVo-0006Kh-L8; Mon, 26 Feb 2024 11:07:29 -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 1redVg-0005xM-OL; Mon, 26 Feb 2024 11:07:26 -0500 Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Tk54l1vTTz67PjK; Tue, 27 Feb 2024 00:03:19 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id 9CDB7140A35; Tue, 27 Feb 2024 00:07:02 +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 16:07:02 +0000 Date: Mon, 26 Feb 2024 16:07:00 +0000 To: Zhao Liu CC: 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?= , Markus Armbruster , Paolo Bonzini , Michael Tokarev , , , , Zhao Liu Subject: Re: [PATCH v2 1/7] hw/cxl/cxl-host: Fix missing ERRP_GUARD() in cxl_fixed_memory_window_config() Message-ID: <20240226160700.00007286@Huawei.com> In-Reply-To: <20240223085653.1255438-2-zhao1.liu@linux.intel.com> References: <20240223085653.1255438-1-zhao1.liu@linux.intel.com> <20240223085653.1255438-2-zhao1.liu@linux.intel.com> 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: lhrpeml500002.china.huawei.com (7.191.160.78) 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+alex.bennee=linaro.org@nongnu.org Sender: qemu-devel-bounces+alex.bennee=linaro.org@nongnu.org X-TUID: z3RKoZs0uSAJ On Fri, 23 Feb 2024 16:56:47 +0800 Zhao Liu wrote: > 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. > ... > * 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. > > But in cxl_fixed_memory_window_config(), @errp is dereferenced in 2 > places without ERRP_GUARD(): > > 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; > } > > For the above 2 places, we check "*errp", because neither function > returns a suitable error code. And 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() hasn't triggered the bug that > dereferencing the NULL @errp. > > 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 > Reviewed-by: Markus Armbruster Acked-by: Jonathan Cameron > --- > Suggested by credit: > Markus: Referred his explanation about ERRP_GUARD(). > --- > v2: > * Add the @errp dereference code in commit message to make review > easier. (Markus) > --- > 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;