From nobody Wed Dec 17 09:14:23 2025 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 D5536C54EF8 for ; Tue, 23 Aug 2022 10:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356924AbiHWKwo (ORCPT ); Tue, 23 Aug 2022 06:52:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355645AbiHWKo7 (ORCPT ); Tue, 23 Aug 2022 06:44:59 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC88E6CD2E; Tue, 23 Aug 2022 02:10:48 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A2490B81C63; Tue, 23 Aug 2022 09:10:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12B21C433C1; Tue, 23 Aug 2022 09:10:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661245846; bh=DL8DDS1N7fZYVKITeuH0f7IEW0g5uIjiciMQzAzvZsQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v/hFJSCFpK0IFP64+OF8lJ9qC0b1ErmG2RWKkGUKV2ItM+RsKFNnutZoW8UqWYnh7 tvAyGng2yp0AY8f20cEPBTbzSAMtD6TRsG+AZtoFNXVFtFoCMdCM8JsqFIVUxlWArk k0+nx/GWhrljsq4nB2W0+c3pSzX/cvw8Ow8dWVMQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Siddh Raman Pant , Ingo Molnar , Sasha Levin Subject: [PATCH 4.19 178/287] x86/numa: Use cpumask_available instead of hardcoded NULL check Date: Tue, 23 Aug 2022 10:25:47 +0200 Message-Id: <20220823080106.765499324@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080100.268827165@linuxfoundation.org> References: <20220823080100.268827165@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Siddh Raman Pant [ Upstream commit 625395c4a0f4775e0fe00f616888d2e6c1ba49db ] GCC-12 started triggering a new warning: arch/x86/mm/numa.c: In function =E2=80=98cpumask_of_node=E2=80=99: arch/x86/mm/numa.c:916:39: warning: the comparison will always evaluate a= s =E2=80=98false=E2=80=99 for the address of =E2=80=98node_to_cpumask_map= =E2=80=99 will never be NULL [-Waddress] 916 | if (node_to_cpumask_map[node] =3D=3D NULL) { | ^~ node_to_cpumask_map is of type cpumask_var_t[]. When CONFIG_CPUMASK_OFFSTACK is set, cpumask_var_t is typedef'd to a pointer for dynamic allocation, else to an array of one element. The "wicked game" can be checked on line 700 of include/linux/cpumask.h. The original code in debug_cpumask_set_cpu() and cpumask_of_node() were probably written by the original authors with CONFIG_CPUMASK_OFFSTACK=3Dy (i.e. dynamic allocation) in mind, checking if the cpumask was available via a direct NULL check. When CONFIG_CPUMASK_OFFSTACK is not set, GCC gives the above warning while compiling the kernel. Fix that by using cpumask_available(), which does the NULL check when CONFIG_CPUMASK_OFFSTACK is set, otherwise returns true. Use it wherever such checks are made. Conditional definitions of cpumask_available() can be found along with the definition of cpumask_var_t. Check the cpumask.h reference mentioned above. Fixes: c032ef60d1aa ("cpumask: convert node_to_cpumask_map[] to cpumask_var= _t") Fixes: de2d9445f162 ("x86: Unify node_to_cpumask_map handling between 32 an= d 64bit") Signed-off-by: Siddh Raman Pant Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20220731160913.632092-1-code@siddh.me Signed-off-by: Sasha Levin --- arch/x86/mm/numa.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index fa150855647c..b4ff063a4371 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -826,7 +826,7 @@ void debug_cpumask_set_cpu(int cpu, int node, bool enab= le) return; } mask =3D node_to_cpumask_map[node]; - if (!mask) { + if (!cpumask_available(mask)) { pr_err("node_to_cpumask_map[%i] NULL\n", node); dump_stack(); return; @@ -872,7 +872,7 @@ const struct cpumask *cpumask_of_node(int node) dump_stack(); return cpu_none_mask; } - if (node_to_cpumask_map[node] =3D=3D NULL) { + if (!cpumask_available(node_to_cpumask_map[node])) { printk(KERN_WARNING "cpumask_of_node(%d): no node_to_cpumask_map!\n", node); --=20 2.35.1