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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C1AD1C43334 for ; Tue, 4 Sep 2018 17:40:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7602C2082B for ; Tue, 4 Sep 2018 17:40:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7602C2082B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727407AbeIDWG3 (ORCPT ); Tue, 4 Sep 2018 18:06:29 -0400 Received: from mga09.intel.com ([134.134.136.24]:1701 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726437AbeIDWG3 (ORCPT ); Tue, 4 Sep 2018 18:06:29 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Sep 2018 10:40:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,329,1531810800"; d="scan'208";a="260644333" Received: from chenyu-desktop.sh.intel.com ([10.239.160.116]) by fmsmga006.fm.intel.com with ESMTP; 04 Sep 2018 10:40:20 -0700 From: Chen Yu To: Fenghua Yu , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Chen Yu , Reinette Chatre , Tony Luck Subject: [PATCH][RFC] x86/intel_rdt: Do not display size for non-CAT resource Date: Wed, 5 Sep 2018 01:46:14 +0800 Message-Id: <20180904174614.26682-1-yu.c.chen@intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On a platform with MB resource enabled, a divided-by-zero exception is triggered when accessing 'size': [ 151.193447] divide error: 0000 [#1] SMP PTI [ 151.197743] CPU: 93 PID: 1929 Comm: cat Not tainted 4.19.0-rc2-debug-rdt+ #25 [ 151.205070] Hardware name: Dell Inc. PowerEdge R640/0CRT1G, BIOS 1.3.7 02/08/2018 [ 151.212783] RIP: 0010:rdtgroup_cbm_to_size+0x7e/0xa0 [ 151.237172] RSP: 0018:ffffb3454f90bd88 EFLAGS: 00010246 [ 151.242538] RAX: 00000000023c0000 RBX: 0000000000000000 RCX: 0000000000000003 [ 151.249878] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 [ 151.257213] RBP: ffff96ff0089e000 R08: 0000000000000000 R09: 0000000000aaaaaa [ 151.264544] R10: ffffb3454f90bd8c R11: 00000000ffffffff R12: ffffffffb5028910 [ 151.271887] R13: ffffffffb5028910 R14: 0000000000000064 R15: ffff96ff0089e000 [ 151.279217] FS: 00007f95a623a500(0000) GS:ffff97170f9c0000(0000) knlGS:0000000000000000 [ 151.287532] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 151.293432] CR2: 00007f95a6217000 CR3: 00000023f696c003 CR4: 00000000007606e0 [ 151.300766] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 151.308094] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 151.315426] PKRU: 55555554 [ 151.318212] Call Trace: [ 151.320732] rdtgroup_size_show+0x11a/0x1d0 [ 151.325039] seq_read+0xd8/0x3b0 [ 151.328363] __vfs_read+0x36/0x170 [ 151.331857] vfs_read+0x89/0x130 [ 151.335179] ksys_read+0x52/0xc0 [ 151.338500] do_syscall_64+0x5b/0x180 [ 151.342261] entry_SYSCALL_64_after_hwframe+0x44/0xa9 This is because for MB resource, the r->cache.cbm_len is zero, thus calculating size in rdtgroup_cbm_to_size() will trigger the exception. Fix this issue by not exposing 'size' for non-CAT resources. Fixes: d9b48c86eb38 ("x86/intel_rdt: Display resource groups' allocations in bytes") Cc: Reinette Chatre Cc: Fenghua Yu Cc: Tony Luck Cc: Thomas Gleixner Signed-off-by: Chen Yu --- arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index b799c00bef09..53fd07b2f61a 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -1329,7 +1329,7 @@ static struct rftype res_common_files[] = { .mode = 0444, .kf_ops = &rdtgroup_kf_single_ops, .seq_show = rdtgroup_size_show, - .fflags = RF_CTRL_BASE, + .fflags = RF_CTRL_INFO | RFTYPE_RES_CACHE, }, }; -- 2.17.1