From nobody Wed Apr 8 10:02:29 2026 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 534A5C25B08 for ; Sat, 20 Aug 2022 08:39:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344605AbiHTIjS (ORCPT ); Sat, 20 Aug 2022 04:39:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48502 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231132AbiHTIjQ (ORCPT ); Sat, 20 Aug 2022 04:39:16 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ADE927B0F for ; Sat, 20 Aug 2022 01:39:14 -0700 (PDT) Received: from zn.tnic (p200300ea971b9849329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:971b:9849:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 2A5E61EC0657; Sat, 20 Aug 2022 10:39:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1660984749; 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: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=TD86MjNzNK/6ONxM4dB6JHGrVjxPZZILCR5gKUKE7pM=; b=hNu7J36bytXQs7ZS+C9/PTH/fI17VsllEYVpvHmn0jY+W0vw3WHrqorUSwSzpVgrNEZmjx HnnQQd9pd6cXXY8Ht3Tj6CyIzAlhwLVn2QKzlQuiessE2vm44iSBYLX7jrqcIsX99Sw9w1 oCSJHlY6kYq6vJM0Fn+l5DiIMy4PypA= Date: Sat, 20 Aug 2022 10:39:03 +0200 From: Borislav Petkov To: Saurabh Singh Sengar Cc: ssengar@microsoft.com, mikelley@microsoft.com, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, peterz@infradead.org, tim.c.chen@linux.intel.com, will@kernel.org, song.bao.hua@hisilicon.com, suravee.suthikulpanit@amd.com, linux-kernel@vger.kernel.org Subject: [PATCH] x86/cacheinfo: Add a cpu_llc_shared_mask() UP variant Message-ID: References: <1660148115-302-1-git-send-email-ssengar@linux.microsoft.com> <20220818045225.GA9054@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> <20220818122925.GA8507@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> <20220819174659.GA16818@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220819174659.GA16818@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On Fri, Aug 19, 2022 at 10:46:59AM -0700, Saurabh Singh Sengar wrote: > Yes, this patch fixes this segfault. Thx! Reported-by: Saurabh Sengar --- From: Borislav Petkov On a CONFIG_SMP=3Dn kernel, the LLC shared mask is 0, which prevents __cache_amd_cpumap_setup() from doing the L3 masks setup, and more specifically from setting up the shared_cpu_map and shared_cpu_list files in sysfs, leading to lscpu from util-linux getting confused and segfaulting. Add a cpu_llc_shared_mask() UP variant which returns a mask with a single bit set, i.e., for CPU0. Fixes: 2b83809a5e6d ("x86/cpu/amd: Derive L3 shared_cpu_map from cpu_llc_sh= ared_mask") Reported-by: Saurabh Sengar Signed-off-by: Borislav Petkov Cc: Link: https://lore.kernel.org/r/1660148115-302-1-git-send-email-ssengar@lin= ux.microsoft.com --- arch/x86/include/asm/smp.h | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 81a0211a372d..a73bced40e24 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -21,16 +21,6 @@ DECLARE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id); DECLARE_PER_CPU_READ_MOSTLY(u16, cpu_l2c_id); DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number); =20 -static inline struct cpumask *cpu_llc_shared_mask(int cpu) -{ - return per_cpu(cpu_llc_shared_map, cpu); -} - -static inline struct cpumask *cpu_l2c_shared_mask(int cpu) -{ - return per_cpu(cpu_l2c_shared_map, cpu); -} - DECLARE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid); DECLARE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid); DECLARE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid); @@ -172,6 +162,16 @@ extern int safe_smp_processor_id(void); # define safe_smp_processor_id() smp_processor_id() #endif =20 +static inline struct cpumask *cpu_llc_shared_mask(int cpu) +{ + return per_cpu(cpu_llc_shared_map, cpu); +} + +static inline struct cpumask *cpu_l2c_shared_mask(int cpu) +{ + return per_cpu(cpu_l2c_shared_map, cpu); +} + #else /* !CONFIG_SMP */ #define wbinvd_on_cpu(cpu) wbinvd() static inline int wbinvd_on_all_cpus(void) @@ -179,6 +179,11 @@ static inline int wbinvd_on_all_cpus(void) wbinvd(); return 0; } + +static inline struct cpumask *cpu_llc_shared_mask(int cpu) +{ + return (struct cpumask *)cpumask_of(0); +} #endif /* CONFIG_SMP */ =20 extern unsigned disabled_cpus; --=20 2.35.1 --=20 Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette