From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id 579FF8E00F9 for ; Fri, 4 Jan 2019 20:05:03 -0500 (EST) Received: by mail-pf1-f200.google.com with SMTP id 68so38276997pfr.6 for ; Fri, 04 Jan 2019 17:05:03 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id q24si14005799pgi.334.2019.01.04.17.05.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 04 Jan 2019 17:05:01 -0800 (PST) Date: Fri, 4 Jan 2019 17:04:59 -0800 From: Andrew Morton Subject: Re: [Bug 202149] New: NULL Pointer Dereference in __split_huge_pmd on PPC64LE Message-Id: <20190104170459.c8c7fa57ba9bc8a69dee5666@linux-foundation.org> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org Cc: bugzilla-daemon@bugzilla.kernel.org, kernel@bluematt.me (switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Fri, 04 Jan 2019 22:49:52 +0000 bugzilla-daemon@bugzilla.kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=202149 > > Bug ID: 202149 > Summary: NULL Pointer Dereference in __split_huge_pmd on > PPC64LE I think that trace is pointing at the ppc-specific pgtable_trans_huge_withdraw()? > Product: Memory Management > Version: 2.5 > Kernel Version: 4.19.13 > Hardware: All > OS: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Other > Assignee: akpm@linux-foundation.org > Reporter: kernel@bluematt.me > Regression: No > > Kernel is actually 4.19.13 + this commit to fix mpt3sas, though I also saw this > fault with a different version of mpt3sas patched into an earlier 4.19 kernel > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23c3828aa2f84edec7020c7397a22931e7a879e1 > . Config is roughly Debian's default config + 4K pages instead of the default > 64K. > > [ 9531.579895] Unable to handle kernel paging request for data at address > 0x00000000 > [ 9531.579918] Faulting instruction address: 0xc000000000076c64 > [ 9531.579930] Oops: Kernel access of bad area, sig: 11 [#1] > [ 9531.579948] LE SMP NR_CPUS=2048 NUMA PowerNV > [ 9531.579960] Modules linked in: binfmt_misc veth xt_nat tap > nft_chain_nat_ipv4 nft_chain_route_ipv4 tun btrfs zstd_compress zstd_decompress > xxhash ipip tunnel4 ip_tunnel ipt_MASQUERADE nf_nat_ipv4 nf_nat nf_conntrack > nf_defrag_ipv6 nf_defrag_ipv4 xt_DSCP xt_dscp nft_counter xt_tcpudp nft_compat > nf_tables nfnetlink amdgpu chash gpu_sched ast snd_hda_codec_hdmi ttm > drm_kms_helper snd_hda_intel snd_hda_codec drm sg snd_hda_core snd_hwdep > snd_pcm uas drm_panel_orientation_quirks syscopyarea sysfillrect snd_timer > sysimgblt fb_sys_fops tg3 mpt3sas snd i2c_algo_bit ofpart ipmi_powernv opal_prd > ipmi_devintf soundcore ipmi_msghandler powernv_flash libphy mtd raid_class > scsi_transport_sas at24 ip_tables x_tables autofs4 ext4 crc16 mbcache jbd2 > fscrypto sd_mod raid10 raid456 crc32c_generic libcrc32c async_raid6_recov > [ 9531.580142] async_memcpy async_pq evdev hid_generic usbhid hid raid6_pq > async_xor xor async_tx raid1 raid0 multipath linear md_mod usb_storage dm_crypt > dm_mod algif_skcipher af_alg ecb xts xhci_pci vmx_crypto xhci_hcd usbcore nvme > nvme_core usb_common > [ 9531.580219] CPU: 9 PID: 4762 Comm: rustc Not tainted 4.19.0-2-powerpc64le #1 > Debian 4.19.13-1 > [ 9531.580250] NIP: c000000000076c64 LR: c00000000037ec38 CTR: > c0000000000471e0 > [ 9531.580280] REGS: c0000001a4f6f840 TRAP: 0300 Not tainted > (4.19.0-2-powerpc64le Debian 4.19.13-1) > [ 9531.580311] MSR: 9000000000009033 CR: 24202848 > XER: 00000000 > [ 9531.580337] CFAR: c00000000037ec34 DAR: 0000000000000000 DSISR: 40000000 > IRQMASK: 0 > GPR00: c00000000037ec38 c0000001a4f6fac0 c0000000010a5800 > c0000008b1a2ec00 > GPR04: c0000001a0ccaf80 0000000000000800 c000000001202e60 > c000000001202de0 > GPR08: 0000000000000009 c00a000006833280 c00a000000000000 > c0000000010b9fd8 > GPR12: 0000000000002000 c000000fffff9600 00003fff40000000 > 0001000000000000 > GPR16: e61fffffffffffff fffffffffffffe7f 0000000000000001 > c00a0000065f48a8 > GPR20: c0000001a0ccaf80 0002000000000000 c0000008b1a2ec00 > c000000001202de0 > GPR24: c00a000019a20000 c0000008b1a2ec00 c0000001a0ccaf80 > c0000006f001c5b0 > GPR28: c00a000006833280 c000000001202e68 00003fff3e000000 > 0000000000000000 > [ 9531.580483] NIP [c000000000076c64] > radix__pgtable_trans_huge_withdraw+0x94/0x160 > [ 9531.580506] LR [c00000000037ec38] __split_huge_pmd+0x588/0xcc0 > [ 9531.580524] Call Trace: > [ 9531.580541] [c0000001a4f6fac0] [c0000001a4f6fb10] 0xc0000001a4f6fb10 > (unreliable) > [ 9531.580572] [c0000001a4f6faf0] [c00000000037ebbc] > __split_huge_pmd+0x50c/0xcc0 > [ 9531.580605] [c0000001a4f6fbb0] [c00000000032aeb8] > move_page_tables+0x438/0xd30 > [ 9531.580637] [c0000001a4f6fcc0] [c00000000032b8fc] move_vma+0x14c/0x370 > [ 9531.580669] [c0000001a4f6fd60] [c00000000032c0a8] sys_mremap+0x588/0x670 > [ 9531.580702] [c0000001a4f6fe30] [c00000000000b9e4] system_call+0x5c/0x70 > [ 9531.580732] Instruction dump: > [ 9531.580760] 0b0a0000 e9060000 e9470000 7d294030 7d2907b4 79291f24 7d2900d0 > 7d292038 > [ 9531.580797] 7929a402 79293664 7d2a4a14 ebe90010 7fbf5040 419e0064 > 7c0802a6 > [ 9531.580837] ---[ end trace 21ba871647464d8b ]--- > > -- > You are receiving this mail because: > You are the assignee for the bug.