Message-ID: <b9c78f92-8f3c-6d78-21fe-a5fd832fd179@huaweicloud.com>
Date: Mon, 28 Apr 2025 15:39:35 +0800
From: Yu Kuai <yukuai1@...weicloud.com>
To: Venkat Rao Bagalkote <venkat88@...ux.ibm.com>,
 LKML <linux-kernel@...r.kernel.org>, linux-block@...r.kernel.org,
 Nilay Shroff <nilay@...ux.ibm.com>, shinichiro.kawasaki@....com,
 Madhavan Srinivasan <maddy@...ux.ibm.com>, "yukuai (C)" <yukuai3@...wei.com>
Subject: Re: [mainline]WARNING: CPU: 29 PID: 1121679 at block/genhd.c:302
 unregister_blkdev+0x1e8/0x2b0

Hi,

在 2025/04/28 15:07, Venkat Rao Bagalkote 写道:
> Hello,
> 
> 
> I am observing kernel warnings on the mainline kernel, while running 
> block_dev Tests from LTP test suite, on IBM Power servers.
> 
> 
> Repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> 
> 
> I have not started the bisection yet.
> 
> 
> Warnings:
> 
> 
> [13323.500222] ltp_block_dev: Test Case 7: unregister_blkdev() with major=0
> [13323.500232] ------------[ cut here ]------------
> [13323.500236] WARNING: CPU: 29 PID: 1121679 at block/genhd.c:302 
> unregister_blkdev+0x1e8/0x2b0
> [13323.500245] Modules linked in: ltp_block_dev(O) dummy veth 
> dns_resolver tun brd overlay exfat vfat fat btrfs blake2b_generic xor 
> raid6_pq zstd_compress xfs loop sctp ip6_udp_tunnel udp_tunnel 
> nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet 
> nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat 
> nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 bonding tls rfkill ip_set 
> nf_tables nfnetlink pseries_rng vmx_crypto dax_pmem fuse ext4 crc16 
> mbcache jbd2 sd_mod sg nd_pmem nd_btt papr_scm ibmvscsi 
> scsi_transport_srp ibmveth libnvdimm [last unloaded: ltp_fw_load(O)]
> [13323.500297] CPU: 29 UID: 0 PID: 1121679 Comm: block_dev Kdump: loaded 
> Tainted: G   M       O  K     6.15.0-rc3-gbc3372351d0c #1 VOLUNTARY
> [13323.500304] Tainted: [M]=MACHINE_CHECK, [O]=OOT_MODULE, [K]=LIVEPATCH
> [13323.500313] NIP:  c000000000882d40 LR: c000000000882bc0 CTR: 
> c000000000882b58
> [13323.500317] REGS: c00000006ff0f8b0 TRAP: 0700   Tainted: G M       O 
> K      (6.15.0-rc3-gbc3372351d0c)
> [13323.500322] MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 
> 28008222  XER: 2004000d
> [13323.500331] CFAR: c000000000882be4 IRQMASK: 0
> [13323.500331] GPR00: c000000000882bc0 c00000006ff0fb50 c000000001688100 
> c000000002fdb2e8
> [13323.500331] GPR04: c008000006790118 000000000000000d 000000000000003b 
> fffffffffffe0000
> [13323.500331] GPR08: 0000000000000000 0000000000000000 0000000000000000 
> c008000006691498
> [13323.500331] GPR12: c000000000882b58 c000000efde70300 0000000000000000 
> 0000000000000000
> [13323.500331] GPR16: 0000000000000000 0000000000000000 0000000000000000 
> 0000000000000000
> [13323.500331] GPR20: 0000000000000000 0000000000000000 0000000000000000 
> 0000000000000000
> [13323.500331] GPR24: 0000000000000000 0000000000000000 c0000000671767a0 
> c008000006790118
> [13323.500331] GPR28: c000000002bca9b8 c000000002fdaae8 0000000000000000 
> 0000000000000000
> [13323.500376] NIP [c000000000882d40] unregister_blkdev+0x1e8/0x2b0
> [13323.500381] LR [c000000000882bc0] unregister_blkdev+0x68/0x2b0
> [13323.500386] Call Trace:
> [13323.500388] [c00000006ff0fb50] [c000000000882bb0] 
> unregister_blkdev+0x58/0x2b0 (unreliable)
> [13323.500395] [c00000006ff0fba0] [c008000006691058] 
> sys_tcase+0x804/0x938 [ltp_block_dev]
> [13323.500401] [c00000006ff0fc80] [c000000000ac2454] 
> dev_attr_store+0x34/0x50
> [13323.500408] [c00000006ff0fca0] [c000000000737d6c] 
> sysfs_kf_write+0x78/0x8c
> [13323.500413] [c00000006ff0fcc0] [c0000000007367cc] 
> kernfs_fop_write_iter+0x1b4/0x2a4
> [13323.500419] [c00000006ff0fd10] [c000000000628d28] vfs_write+0x38c/0x488
> [13323.500424] [c00000006ff0fdc0] [c000000000629158] ksys_write+0x84/0x140
> [13323.500429] [c00000006ff0fe10] [c0000000000332f8] 
> system_call_exception+0x138/0x330
> [13323.500436] [c00000006ff0fe50] [c00000000000d05c] 
> system_call_vectored_common+0x15c/0x2ec
> [13323.500442] --- interrupt: 3000 at 0x7fff92933e74
> [13323.500446] NIP:  00007fff92933e74 LR: 00007fff92933e74 CTR: 
> 0000000000000000
> [13323.500450] REGS: c00000006ff0fe80 TRAP: 3000   Tainted: G M       O 
> K      (6.15.0-rc3-gbc3372351d0c)
> [13323.500455] MSR:  800000000280f033 
> <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE>  CR: 44002424  XER: 00000000
> [13323.500466] IRQMASK: 0
> [13323.500466] GPR00: 0000000000000004 00007fffd5bca940 0000000010067f00 
> 0000000000000003
> [13323.500466] GPR04: 0000000030a90b50 0000000000000001 0000000000000000 
> 0000000000000001
> [13323.500466] GPR08: 0000000000000000 0000000000000000 0000000000000000 
> 0000000000000000
> [13323.500466] GPR12: 0000000000000000 00007fff92c5a5c0 0000000000000000 
> 00000000100332d0
> [13323.500466] GPR16: 0000000010033608 0000000010033ce4 0000000010033ce8 
> 0000000010033b60
> [13323.500466] GPR20: 0000000000000001 0000000000000000 0000000000000000 
> 0000000000000000
> [13323.500466] GPR24: 0000000010060848 00000000100307b0 0000000030a90b50 
> 0000000000000001
> [13323.500466] GPR28: 0000000000000001 0000000030a902a0 0000000030a90b50 
> 0000000000000001
> [13323.500508] NIP [00007fff92933e74] 0x7fff92933e74
> [13323.500512] LR [00007fff92933e74] 0x7fff92933e74
> [13323.500515] --- interrupt: 3000
> [13323.500517] Code: 7d404c28 39200000 7d094bf8 7d0753f8 7d293b39 
> 408200cc 389b0040 38630040 48851ecd 60000000 48000084 60000000 
> <0fe00000> a14d0c82 3be00000 7da96b78
> [13323.500531] ---[ end trace 0000000000000000 ]---
> [13323.500535] ltp_block_dev: Test Case Result: PASS
> 
> 
> If you happen to fix this, please add below tag.

Nothing should be fixed, unregister_blkdev() is called directly by your
testcase with major set to 0, the WARNING is expected.

Thanks,
Kuai

> 
> 
> Reported-by: Venkat Rao Bagalkote <venkat88@...ux.ibm.com>
> 
> 
> Regards,
> 
> Venkat.
> 
> 
> .
> 

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