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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 E45D6C4321A for ; Thu, 27 Jun 2019 21:21:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A60D7208CB for ; Thu, 27 Jun 2019 21:21:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lca.pw header.i=@lca.pw header.b="NLu9PuPk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726540AbfF0VVQ (ORCPT ); Thu, 27 Jun 2019 17:21:16 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:33029 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726384AbfF0VVQ (ORCPT ); Thu, 27 Jun 2019 17:21:16 -0400 Received: by mail-qt1-f196.google.com with SMTP id h24so1089053qto.0 for ; Thu, 27 Jun 2019 14:21:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lca.pw; s=google; h=message-id:subject:from:to:cc:date:mime-version :content-transfer-encoding; bh=BnGhhmLs0NKuNQcACyeoZ7fY58jMOrioFdYaVDGXO5k=; b=NLu9PuPkHBmYWLZ8E4QUHmn9nNhXAtdHQH82TM0Dr8TRjBFZZrOIqCUwNaxAIil5Le bVPEEnjZsAO3KxORiGQhnUYvPUseFp0QiGXaNMwrD8YiPBdOh+QkDBaWZQTLHDdtpM0F AgiMVtXg40Dff2IZgnkBNNcJUHbTsa1pcDIhzuV2PKkKQ3fw7U7Czpynfy+GOdskIaYY l4ij8bff1xzTpcA54AetcjD4kx8PXCEGhHLStIDWWVHoPrirTdn+4h3TXndV8F0KzqSp UfggSc+CgJuMY8KOnW8lKxSTwIxr5N346ljeAQD5bMpp7bH+Zpx7jnqSKbnhFtMhZoXb KuJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:mime-version :content-transfer-encoding; bh=BnGhhmLs0NKuNQcACyeoZ7fY58jMOrioFdYaVDGXO5k=; b=R9GdCjQRzgqEsoTrGgzdxh9C4JhdO7I4RHShnwxTBDuMY5pCSmHVtcie8N4kYZqxYf n/dK8Z62jYKSzZO89AHuufgcVESJ7x8vcCq1ebFxBtBLphFziW6KAuudX6/Z77mBgxwv I9EgtO/h2Cw1aNpf1efjOyZtIez6b20xkhgo+AVDF8hUehLxU2p3kVZ2RB8b7UA1d0nM TNVN+ymw7Ug14f194bderd0OShwjpLgAj9pb20e8m1V9FYQdvS7uHnAChg2BHS6OeyfM TNkQp1nZGNf+ktYG9R8KfQfQVqQZVUOJ5Wlh5YQQMVd7/yHfAf9Pe0P6yjx5qGvAHQuw bwew== X-Gm-Message-State: APjAAAWDQ6b3ydoMm/PI9TzhvLsH9KyodnuMa5fNX8jyj8fA0Hq2TA6v 04N//82EzgGCMLP57svhQlTRjA== X-Google-Smtp-Source: APXvYqyucLMnFlL8PrwfSlv+M76FN5qa+AodHhkkhAM/WJtk3b6+nDqi+cN50FBmBZzV1nKbPYK+DQ== X-Received: by 2002:a0c:b521:: with SMTP id d33mr5116673qve.239.1561670474522; Thu, 27 Jun 2019 14:21:14 -0700 (PDT) Received: from dhcp-41-57.bos.redhat.com (nat-pool-bos-t.redhat.com. [66.187.233.206]) by smtp.gmail.com with ESMTPSA id 16sm126561qkl.100.2019.06.27.14.21.13 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Jun 2019 14:21:13 -0700 (PDT) Message-ID: <1561670472.5154.98.camel@lca.pw> Subject: power9 NUMA crash while reading debugfs imc_cmd From: Qian Cai To: "Aneesh Kumar K.V" , Michael Ellerman , Anju T Sudhakar Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Date: Thu, 27 Jun 2019 17:21:12 -0400 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 (3.22.6-10.el7) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Read of debugfs imc_cmd file for a memory-less node will trigger a crash below on this power9 machine which has the following NUMA layout. I don't understand why I only saw it recently on linux-next where it was tested everyday. I can reproduce it back to 4.20 where 4.18 seems work fine. # cat /sys/kernel/debug/powerpc/imc/imc_cmd_252 (On a 4.18-based kernel) 0x0000000000000000 # numactl -H available: 6 nodes (0,8,252-255) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 node 0 size: 130210 MB node 0 free: 128406 MB node 8 cpus: 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 node 8 size: 130784 MB node 8 free: 130051 MB node 252 cpus: node 252 size: 0 MB node 252 free: 0 MB node 253 cpus: node 253 size: 0 MB node 253 free: 0 MB node 254 cpus: node 254 size: 0 MB node 254 free: 0 MB node 255 cpus: node 255 size: 0 MB node 255 free: 0 MB node distances: node   0   8  252  253  254  255    0:  10  40  80  80  80  80    8:  40  10  80  80  80  80   252:  80  80  10  80  80  80   253:  80  80  80  10  80  80   254:  80  80  80  80  10  80   255:  80  80  80  80  80  10 # cat /sys/kernel/debug/powerpc/imc/imc_cmd_252 [ 1139.415461][ T5301] Faulting instruction address: 0xc0000000000d0d58 [ 1139.415492][ T5301] Oops: Kernel access of bad area, sig: 11 [#1] [ 1139.415509][ T5301] LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=256 DEBUG_PAGEALLOC NUMA PowerNV [ 1139.415542][ T5301] Modules linked in: i2c_opal i2c_core ip_tables x_tables xfs sd_mod bnx2x mdio ahci libahci tg3 libphy libata firmware_class dm_mirror dm_region_hash dm_log dm_mod [ 1139.415595][ T5301] CPU: 67 PID: 5301 Comm: cat Not tainted 5.2.0-rc6-next- 20190627+ #19 [ 1139.415634][ T5301] NIP:  c0000000000d0d58 LR: c00000000049aa18 CTR: c0000000000d0d50 [ 1139.415675][ T5301] REGS: c00020194548f9e0 TRAP: 0300   Not tainted  (5.2.0- rc6-next-20190627+) [ 1139.415705][ T5301] MSR:  9000000000009033   CR: 28022822  XER: 00000000 [ 1139.415777][ T5301] CFAR: c00000000049aa14 DAR: 000000000003fc08 DSISR: 40000000 IRQMASK: 0  [ 1139.415777][ T5301] GPR00: c00000000049aa18 c00020194548fc70 c0000000016f8b00 000000000003fc08  [ 1139.415777][ T5301] GPR04: c00020194548fcd0 0000000000000000 0000000014884e73 ffffffff00011eaa  [ 1139.415777][ T5301] GPR08: 000000007eea5a52 c0000000000d0d50 0000000000000000 0000000000000000  [ 1139.415777][ T5301] GPR12: c0000000000d0d50 c000201fff7f8c00 0000000000000000 0000000000000000  [ 1139.415777][ T5301] GPR16: 000000000000000d 00007fffeb0c3368 ffffffffffffffff 0000000000000000  [ 1139.415777][ T5301] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000020000  [ 1139.415777][ T5301] GPR24: 0000000000000000 0000000000000000 0000000000020000 000000010ec90000  [ 1139.415777][ T5301] GPR28: c00020194548fdf0 c00020049a584ef8 0000000000000000 c00020049a584ea8  [ 1139.416116][ T5301] NIP [c0000000000d0d58] imc_mem_get+0x8/0x20 [ 1139.416143][ T5301] LR [c00000000049aa18] simple_attr_read+0x118/0x170 [ 1139.416158][ T5301] Call Trace: [ 1139.416182][ T5301] [c00020194548fc70] [c00000000049a970] simple_attr_read+0x70/0x170 (unreliable) [ 1139.416255][ T5301] [c00020194548fd10] [c00000000054385c] debugfs_attr_read+0x6c/0xb0 [ 1139.416305][ T5301] [c00020194548fd60] [c000000000454c1c] __vfs_read+0x3c/0x70 [ 1139.416363][ T5301] [c00020194548fd80] [c000000000454d0c] vfs_read+0xbc/0x1a0 [ 1139.416392][ T5301] [c00020194548fdd0] [c00000000045519c] ksys_read+0x7c/0x140 [ 1139.416434][ T5301] [c00020194548fe20] [c00000000000b108] system_call+0x5c/0x70 [ 1139.416473][ T5301] Instruction dump: [ 1139.416511][ T5301] 4e800020 60000000 7c0802a6 60000000 7c801d28 38600000 4e800020 60000000  [ 1139.416572][ T5301] 60000000 60000000 7c0802a6 60000000 <7d201c28> 38600000 f9240000 4e800020  [ 1139.416636][ T5301] ---[ end trace c44d1fb4ace04784 ]--- [ 1139.520686][ T5301]  [ 1140.520820][ T5301] Kernel panic - not syncing: Fatal exception