Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753187AbbFDKYJ (ORCPT ); Thu, 4 Jun 2015 06:24:09 -0400 Received: from mail-oi0-f52.google.com ([209.85.218.52]:35035 "EHLO mail-oi0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751983AbbFDKYE convert rfc822-to-8bit (ORCPT ); Thu, 4 Jun 2015 06:24:04 -0400 MIME-Version: 1.0 In-Reply-To: <55701655.9000605@message-id.googlemail.com> References: <55701655.9000605@message-id.googlemail.com> Date: Thu, 4 Jun 2015 18:24:03 +0800 Message-ID: Subject: Re: [REGRESSION] 4.1-rc6 unloading loop OOPS From: Ming Lei To: Stefan Seyfried Cc: LKML Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7713 Lines: 113 On Thu, Jun 4, 2015 at 5:11 PM, Stefan Seyfried wrote: > > Hi all, > > I just tried to unload loop to change the max_part parameter on my > freshly booted 4.1-rc6. > This produced this nice Warning, then an OOPS: > [ 661.382335] ------------[ cut here ]------------ > [ 661.382344] WARNING: CPU: 1 PID: 2903 at ../mm/backing-dev.c:372 bdi_unregister+0x32/0x40() > [ 661.382346] Modules linked in: ctr ccm fuse xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT xt_tcpudp tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables af_packet bnep bluetooth dm_crypt ecb algif_skcipher af_alg xfs libcrc32c iTCO_wdt iTCO_vendor_support snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep snd_pcm_oss snd_pcm dm_mod coretemp kvm_intel arc4 kvm snd_seq iwldvm cdc_ether cdc_acm cdc_wdm usbnet mac80211 mii thinkpad_acpi snd_seq_device snd_timer iwlwifi i2c_i801 snd_mixer_oss pcspkr serio_raw cfg80211 lpc_ich snd mfd_core shpchp mei_me mei soundcore rfkill > [ 661.382393] tpm_tis battery ac tpm wmi acpi_cpufreq i915 i2c_algo_bit drm_kms_helper xhci_pci xhci_hcd drm e1000e ptp pps_core video button fan thermal processor sg loop(-) > [ 661.382408] CPU: 1 PID: 2903 Comm: rmmod Not tainted 4.1.0-rc6-2.g8f2a4d1-desktop #1 > [ 661.382410] Hardware name: LENOVO 74665EG/74665EG, BIOS 6DET71WW (3.21 ) 12/13/2011 > [ 661.382412] 0000000000000000 ffffffff81a4c793 ffffffff8169b34a 0000000000000000 > [ 661.382415] ffffffff81067b71 ffff8802307b5400 0000000000000000 0000000000000000 > [ 661.382418] 00000000ffffffff 0000000000000000 ffffffff8118cdd2 000000000000000e > [ 661.382421] Call Trace: > [ 661.382434] [] dump_trace+0x8c/0x340 > [ 661.382438] [] show_stack_log_lvl+0xfc/0x1a0 > [ 661.382442] [] show_stack+0x21/0x50 > [ 661.382447] [] dump_stack+0x47/0x67 > [ 661.382452] [] warn_slowpath_common+0x81/0xb0 > [ 661.382457] [] bdi_unregister+0x32/0x40 > [ 661.382461] [] del_gendisk+0x110/0x280 > [ 661.382470] [] loop_remove+0x21/0x50 [loop] > [ 661.382476] [] loop_exit_cb+0x11/0x20 [loop] > [ 661.382480] [] idr_for_each+0xa3/0xf0 > [ 661.382487] [] loop_exit+0x30/0xb1a [loop] > [ 661.382492] [] SyS_delete_module+0x1ac/0x230 > [ 661.382497] [] system_call_fastpath+0x16/0x75 > [ 661.382502] [<00007ff635777f37>] 0x7ff635777f37 > [ 661.382504] ---[ end trace 7b8e0f39c45cf571 ]--- > [ 661.449507] BUG: unable to handle kernel NULL pointer dereference at 0000000000000108 > [ 661.449548] IP: [] kobject_del+0xe/0x50 > [ 661.449586] PGD 1d8f2c067 PUD 1d8e7c067 PMD 0 > [ 661.449618] Oops: 0000 [#1] PREEMPT SMP > [ 661.449649] Modules linked in: ctr ccm fuse xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT xt_tcpudp tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables af_packet bnep bluetooth dm_crypt ecb algif_skcipher af_alg xfs libcrc32c iTCO_wdt iTCO_vendor_support snd_hda_codec_conexant snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hda_core snd_hwdep snd_pcm_oss snd_pcm dm_mod coretemp kvm_intel arc4 kvm snd_seq iwldvm cdc_ether cdc_acm cdc_wdm usbnet mac80211 mii thinkpad_acpi snd_seq_device snd_timer iwlwifi i2c_i801 snd_mixer_oss pcspkr serio_raw cfg80211 lpc_ich snd mfd_core shpchp mei_me mei soundcore rfkill > [ 661.449906] tpm_tis battery ac tpm wmi acpi_cpufreq i915 i2c_algo_bit drm_kms_helper xhci_pci xhci_hcd drm e1000e ptp pps_core video button fan thermal processor sg loop(-) > [ 661.449993] CPU: 0 PID: 2903 Comm: rmmod Tainted: G W 4.1.0-rc6-2.g8f2a4d1-desktop #1 > [ 661.450025] Hardware name: LENOVO 74665EG/74665EG, BIOS 6DET71WW (3.21 ) 12/13/2011 > [ 661.450055] task: ffff8802322220d0 ti: ffff8801d8d78000 task.ti: ffff8801d8d78000 > [ 661.450084] RIP: 0010:[] [] kobject_del+0xe/0x50 > [ 661.450118] RSP: 0018:ffff8801d8d7bd78 EFLAGS: 00010206 > [ 661.450146] RAX: ffff88023004ab60 RBX: 00000000000000d8 RCX: 0000000000000001 > [ 661.450175] RDX: 0000000000000000 RSI: ffff88023078c4d8 RDI: 00000000000000d8 > [ 661.450203] RBP: ffff88023004f800 R08: ffff88023215a8b8 R09: ffff88023215b0c8 > [ 661.450217] R10: 0001526900015261 R11: 000000000000000e R12: 0000000000000000 > [ 661.450217] R13: ffff8802300577e0 R14: ffff88023004f400 R15: ffffffffa0000380 > [ 661.450217] FS: 00007ff636056700(0000) GS:ffff88023bc00000(0000) knlGS:0000000000000000 > [ 661.450217] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 661.450217] CR2: 0000000000000108 CR3: 000000023223f000 CR4: 00000000000407f0 > [ 661.450217] Stack: > [ 661.450217] ffffffffa0000380 0000000000000001 ffff88023004f800 ffffffff8133abed > [ 661.450217] ffff8802319eba80 ffff8802300577e0 ffff88023004f800 ffffffff8133ac61 > [ 661.450217] ffff8802300577e0 ffff88023004f400 0000000000000000 00000000ffffffff > [ 661.450217] Call Trace: > [ 661.450217] [] blk_mq_unregister_hctx.part.0+0x3d/0x60 > [ 661.450217] [] blk_mq_unregister_disk+0x51/0xe0 > [ 661.450217] [] blk_unregister_queue+0x2c/0x90 > [ 661.450217] [] del_gendisk+0x118/0x280 > [ 661.450217] [] loop_remove+0x21/0x50 [loop] > [ 661.450217] [] loop_exit_cb+0x11/0x20 [loop] > [ 661.450217] [] idr_for_each+0xa3/0xf0 > [ 661.450217] [] loop_exit+0x30/0xb1a [loop] > [ 661.450217] [] SyS_delete_module+0x1ac/0x230 > [ 661.450217] [] system_call_fastpath+0x16/0x75 > [ 661.450217] [<00007ff635777f37>] 0x7ff635777f37 > [ 661.450217] Code: 48 83 c7 18 e9 54 ff ff ff 0f 1f 40 00 5b c3 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 fb 48 83 ec 08 48 85 ff 74 2e <48> 8b 6f 30 e8 09 cc ef ff 48 89 ef e8 a1 98 ef ff 80 63 3c fd > [ 661.450217] RIP [] kobject_del+0xe/0x50 > [ 661.450217] RSP > [ 661.450217] CR2: 0000000000000108 > [ 661.466690] ---[ end trace 7b8e0f39c45cf572 ]--- > > I can reproduce the backtrace after a reboot once (subsequent modprobe/rmmod loop > do not complain anymore), but not the OOPS. One fix[1] was just merged to linus tree, and could you test that to see if your issue can be addressed? [1] http://marc.info/?t=143201518300001&r=1&w=2 Thanks, Ming > > Best regards, > > Stefan > -- > Stefan Seyfried > Linux Consultant & Developer -- GPG Key: 0x731B665B > > B1 Systems GmbH > Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de > GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537 > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/