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 9849CC35FF1 for ; Wed, 19 Mar 2025 06:51:29 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tunG9-0002EK-6p; Wed, 19 Mar 2025 02:50:37 -0400 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 1tunG7-0002E7-Nc for qemu-devel@nongnu.org; Wed, 19 Mar 2025 02:50:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tunG5-0007uu-2r for qemu-devel@nongnu.org; Wed, 19 Mar 2025 02:50:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1742367031; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cAYG9zY2LBGvLrbCZZO1l00joI+QSfROI0w3FWaht+g=; b=hDXwvgYxTtmj8rvYjtDlUoz+oHz6muwBp7CrfSn1nVLOvX+4gy+cTkfuS/he3wY2Nz+UQ5 ysvlSHeulOXfP+qdnRTWSXlPxY2keYQzfiG1BeM2BRyaqkxwVRLg/pkvFeuPstWD3nI+GP rsVoYNqImenTmmTlNGQ4xZ4Qgus2+Tc= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-27-LTsdUfkvMcGeuPLM2oVjWg-1; Wed, 19 Mar 2025 02:50:24 -0400 X-MC-Unique: LTsdUfkvMcGeuPLM2oVjWg-1 X-Mimecast-MFC-AGG-ID: LTsdUfkvMcGeuPLM2oVjWg_1742367024 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4B90619560B0; Wed, 19 Mar 2025 06:50:23 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.22.74.4]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 40FC3180174E; Wed, 19 Mar 2025 06:50:21 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 302C321E66C5; Wed, 19 Mar 2025 07:50:17 +0100 (CET) From: Markus Armbruster To: Bibo Mao Cc: Song Gao , Jiaxun Yang , qemu-devel@nongnu.org, Paolo Bonzini Subject: Re: [PATCH v4 2/4] hw/loongarch/virt: Remove unnecessary NULL pointer In-Reply-To: <20250319020847.1511759-3-maobibo@loongson.cn> (Bibo Mao's message of "Wed, 19 Mar 2025 10:08:45 +0800") References: <20250319020847.1511759-1-maobibo@loongson.cn> <20250319020847.1511759-3-maobibo@loongson.cn> Date: Wed, 19 Mar 2025 07:50:17 +0100 Message-ID: <87v7s5345y.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.332, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Bibo Mao writes: > There is NULL pointer checking function error_propagate() already, > it is not necessary to add checking for function parameter. Here remove > NULL pointer checking with function parameter. I believe the title "Remove unnecessary NULL pointer" and this paragraph are remnants of your initial version, which transformed if (err) { error_propagate(errp, err); } to just error_propagate(errp, err); However, the patch doesn't do that anymore. I think you should drop the paragraph, and replace the title. I apologize for not noticing this earlier. > Since function will return directly when there is error report, this > patch removes combination about error_setg() and error_propagate(), > error_setg() with dest error object is used directly such as: > > error_setg(err); --------> error_setg(errp); > error_propagate(errp, err); return; > return; Yes, much of the patch does this or equivalent transformations. However, there's more; see [*] below. > Signed-off-by: Bibo Mao > --- > hw/loongarch/virt.c | 33 ++++++++++++--------------------- > 1 file changed, 12 insertions(+), 21 deletions(-) > > diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c > index a5840ff968..a9fab39dd8 100644 > --- a/hw/loongarch/virt.c > +++ b/hw/loongarch/virt.c > @@ -859,30 +859,29 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplug_dev, > LoongArchCPU *cpu = LOONGARCH_CPU(dev); > CPUState *cs = CPU(dev); > CPUArchId *cpu_slot; > - Error *err = NULL; > LoongArchCPUTopo topo; > int arch_id; > > if (lvms->acpi_ged) { > if ((cpu->thread_id < 0) || (cpu->thread_id >= ms->smp.threads)) { > - error_setg(&err, > + error_setg(errp, > "Invalid thread-id %u specified, must be in range 1:%u", > cpu->thread_id, ms->smp.threads - 1); > - goto out; > + return; > } > > if ((cpu->core_id < 0) || (cpu->core_id >= ms->smp.cores)) { > - error_setg(&err, > + error_setg(errp, > "Invalid core-id %u specified, must be in range 1:%u", > cpu->core_id, ms->smp.cores - 1); > - goto out; > + return; > } > > if ((cpu->socket_id < 0) || (cpu->socket_id >= ms->smp.sockets)) { > - error_setg(&err, > + error_setg(errp, > "Invalid socket-id %u specified, must be in range 1:%u", > cpu->socket_id, ms->smp.sockets - 1); > - goto out; > + return; > } > > topo.socket_id = cpu->socket_id; > @@ -891,11 +890,11 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplug_dev, > arch_id = virt_get_arch_id_from_topo(ms, &topo); > cpu_slot = virt_find_cpu_slot(ms, arch_id); > if (CPU(cpu_slot->cpu)) { > - error_setg(&err, > + error_setg(errp, > "cpu(id%d=%d:%d:%d) with arch-id %" PRIu64 " exists", > cs->cpu_index, cpu->socket_id, cpu->core_id, > cpu->thread_id, cpu_slot->arch_id); > - goto out; > + return; > } > } else { > /* For cold-add cpu, find empty cpu slot */ > @@ -911,33 +910,24 @@ static void virt_cpu_pre_plug(HotplugHandler *hotplug_dev, > cpu->env.address_space_iocsr = &lvms->as_iocsr; > cpu->phy_id = cpu_slot->arch_id; > cs->cpu_index = cpu_slot - ms->possible_cpus->cpus; > - numa_cpu_pre_plug(cpu_slot, dev, &err); > -out: > - if (err) { > - error_propagate(errp, err); > - } > + numa_cpu_pre_plug(cpu_slot, dev, errp); > } > > static void virt_cpu_unplug_request(HotplugHandler *hotplug_dev, > DeviceState *dev, Error **errp) > { > LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(hotplug_dev); > - Error *err = NULL; > LoongArchCPU *cpu = LOONGARCH_CPU(dev); > CPUState *cs = CPU(dev); > > if (cs->cpu_index == 0) { > - error_setg(&err, "hot-unplug of boot cpu(id%d=%d:%d:%d) not supported", > + error_setg(errp, "hot-unplug of boot cpu(id%d=%d:%d:%d) not supported", > cs->cpu_index, cpu->socket_id, > cpu->core_id, cpu->thread_id); > - error_propagate(errp, err); > return; > } > > - hotplug_handler_unplug_request(HOTPLUG_HANDLER(lvms->acpi_ged), dev, &err); > - if (err) { > - error_propagate(errp, err); > - } > + hotplug_handler_unplug_request(HOTPLUG_HANDLER(lvms->acpi_ged), dev, errp); > } > > static void virt_cpu_unplug(HotplugHandler *hotplug_dev, > @@ -1003,6 +993,7 @@ static void virt_cpu_plug(HotplugHandler *hotplug_dev, > hotplug_handler_plug(HOTPLUG_HANDLER(lvms->acpi_ged), dev, &err); > if (err) { > error_propagate(errp, err); > + return; > } > } cpu_slot = virt_find_cpu_slot(MACHINE(lvms), cpu->phy_id); cpu_slot->cpu = NULL; return; } [*] This is something else. Before the patch, we clear cpu_slot->cpu evem when the last hotplug_handler() fails. Afterwards, we don't. Looks like a bug fix to me. Either mention the fix in the commit message, or split it off into a separate patch. I'd do the latter.