+ CC: Corey Minyard <co...@minyard.net> Misspelled the email address.
On Wed, Aug 6, 2025 at 3:14 PM Frederick Lawler <f...@cloudflare.com> wrote: > > Hi Corey, > > In kernel 6.12.y, while resetting the BMC, we can sometimes hit a hard LOCKUP > watchdog event, especially so while querying the BMC for basic device > information via sysfs. > > I havn't been able to create a consistent reproducer yet, but I suspect > that these occur during high traffic, BMC is resetting, and reading > from the sysfs files in parallel. We're also using KCS to interface > with the BMC. > > I can consistently reproduce hung tasks trivially with the following, > during a BMC reset: > > while true; do cat aux_firmware_revision &>/dev/null; done & > > I tried also tried to load the CPUs with stress-ng, but the best I can do > are the hung tasks. > > I identified that sni_send()[1] could be locked behind the > spin_lock_irqsave() and within the KCS send handler, there's another irq > save lock. I suspect this is where we're getting hung up. Below is a > sample stack trace + log output. > > I'm happy to provide traces and additional information, let me know. > > Links: > [1]: > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/char/ipmi/ipmi_msghandler.c?h=linux-6.12.y#n1899 > > [ 499.564572] [ T27255] ip6_tunnel: pni_gre_814 xmit: Local address not yet > configured! > [ 499.588176] [ T27255] ip6_tunnel: pni_gre_868 xmit: Local address not yet > configured! > [ 499.605284] [ T27255] ip6_tunnel: pni_gre_871 xmit: Local address not yet > configured! > [ 805.906999] [ T12765] usb 1-1: USB disconnect, device number 2 > [ 845.346020] [ T12765] usb 1-1: new high-speed USB device number 3 using > xhci_hcd > [ 845.485453] [ T12765] usb 1-1: New USB device found, idVendor=1d6b, > idProduct=0107, bcdDevice= 1.00 > [ 845.496823] [ T12765] usb 1-1: New USB device strings: Mfr=3, Product=2, > SerialNumber=1 > [ 845.507242] [ T12765] usb 1-1: Product: USB Virtual Hub > [ 845.514946] [ T12765] usb 1-1: Manufacturer: Aspeed > [ 845.522363] [ T12765] usb 1-1: SerialNumber: 00000000 > [ 845.530454] [ T12765] usb 1-1: Device is not authorized for usage > [ 853.774910] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.783794] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.792649] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.801461] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.810291] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.819069] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.827816] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.836581] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.845326] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.854074] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 853.862813] [ C119] ipmi_si IPI0001:00: KCS in invalid state 6 > [ 863.934436] [ T124929] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 863.943420] [ T124929] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 863.952363] [ T124929] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 863.961296] [ T124929] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 878.616336] [ T126542] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 878.624905] [ T126542] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 878.633427] [ T126542] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 878.641954] [ T126542] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 880.310112] [ T126681] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 880.318682] [ T126681] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 880.327083] [ T126681] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 880.335483] [ T126681] ipmi_si IPI0001:00: KCS in invalid state 7 > [ 904.196122] [ C33] watchdog: Watchdog detected hard LOCKUP on cpu 33 > [ 904.196127] [ C97] Uhhuh. NMI received for unknown reason 3d on CPU 97. > [ 904.196126] [ C6] Uhhuh. NMI received for unknown reason 3d on CPU 6. > [ 904.196130] [ C33] Modules linked in: > [ 904.196129] [ C101] Uhhuh. NMI received for unknown reason 3d on CPU > 101. > [ 904.196131] [ C97] Dazed and confused, but trying to continue > [ 904.196131] [ C33] nft_fwd_netdev > [ 904.196131] [ C99] Uhhuh. NMI received for unknown reason 2d on CPU 99. > [ 904.196133] [ C6] Dazed and confused, but trying to continue > [ 904.196133] [ C102] Uhhuh. NMI received for unknown reason 2d on CPU > 102. > [ 904.196134] [ C33] nf_dup_netdev > [ 904.196134] [ C35] Uhhuh. NMI received for unknown reason 2d on CPU 35. > [ 904.196135] [ C101] Dazed and confused, but trying to continue > [ 904.196137] [ C99] Dazed and confused, but trying to continue > [ 904.196137] [ C33] xfrm_interface > [ 904.196136] [ C69] Uhhuh. NMI received for unknown reason 2d on CPU 69. > [ 904.196140] [ C102] Dazed and confused, but trying to continue > [ 904.196140] [ C33] xfrm6_tunnel > [ 904.196138] [ C121] Uhhuh. NMI received for unknown reason 2d on CPU > 121. > [ 904.196140] [ C123] Uhhuh. NMI received for unknown reason 2d on CPU > 123. > [ 904.196142] [ C35] Dazed and confused, but trying to continue > [ 904.196143] [ C69] Dazed and confused, but trying to continue > [ 904.196143] [ C33] nft_numgen > [ 904.196143] [ C61] Uhhuh. NMI received for unknown reason 2d on CPU 61. > [ 904.196144] [ C62] Uhhuh. NMI received for unknown reason 3d on CPU 62. > [ 904.196146] [ C123] Dazed and confused, but trying to continue > [ 904.196147] [ C121] Dazed and confused, but trying to continue > [ 904.196148] [ C58] Dazed and confused, but trying to continue > [ 904.196150] [ C33] nft_log nft_limit sit dummy ipip tunnel4 ip_gre > gre xfrm_user xfrm_algo tls mpls_iptunnel mpls_router nft_ct nf_tables > iptable_raw iptable_nat iptable_mangle ipt_REJECT nf_reject_ipv4 > ip6table_security xt_CT ip6table_raw xt_nat ip6table_nat nf_nat xt_TCPMSS > xt_owner xt_DSCP xt_NFLOG xt_connbytes xt_connlabel xt_statistic xt_connmark > ip6table_mangle xt_limit xt_LOG nf_log_syslog xt_mark xt_conntrack > ip6t_REJECT nf_reject_ipv6 xt_multiport xt_set xt_tcpmss xt_comment xt_tcpudp > ip6table_filter ip6_tables nfnetlink_log udp_diag dm_thin_pool > dm_persistent_data dm_bio_prison dm_bufio iptable_filter veth tcp_diag > inet_diag mpls_gso act_mpls cls_flower cls_bpf sch_ingress ip_set_hash_ip > ip_set_hash_net ip_set tcp_bbr sch_fq tun xt_bpf nf_conntrack nf_defrag_ipv6 > nf_defrag_ipv4 fou6 fou ip_tunnel ip6_udp_tunnel udp_tunnel ip6_tunnel > tunnel6 nvme_fabrics raid0 md_mod essiv dm_crypt trusted asn1_encoder tee > dm_mod dax 8021q garp mrp stp llc ipmi_ssif amd64_edac kvm_amd kvm irqbypass > crc32_pclmul crc32c_intel > [ 904.196247] [ C33] sha512_ssse3 sha256_ssse3 sha1_ssse3 aesni_intel > crypto_simd xhci_pci binfmt_misc acpi_ipmi cryptd ipmi_si nvme rapl > ipmi_devintf i2c_piix4 tiny_power_button bnxt_en xhci_hcd nvme_core ccp > i2c_smbus ipmi_msghandler button fuse configfs nfnetlink efivarfs ip_tables > x_tables bcmcrypt(O) > [ 904.196281] [ C33] CPU: 33 UID: 0 PID: 0 Comm: swapper/33 Kdump: > loaded Tainted: G O 6.12.34-cloudflare-2025.6.9 #1 > [ 904.196286] [ C33] Tainted: [O]=OOT_MODULE > [ 904.196287] [ C33] Hardware name: GIGABYTE > R162-Z12-CD-G11P5/MZ12-HD4-CD, BIOS M10-sig 02/17/2025 > [ 904.196290] [ C33] RIP: 0010:io_idle+0x3/0x30 > [ 904.196298] [ C33] Code: 8b 00 a8 08 75 07 e8 2c e4 ff ff 90 fa e9 c0 > b3 1a 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 89 fa > ec <48> 8b 05 96 42 d4 01 a9 00 00 00 80 75 11 80 3d 4a 42 d4 01 00 75 > [ 904.196301] [ C33] RSP: 0018:ffff9afa88307e70 EFLAGS: 00000093 > [ 904.196304] [ C33] RAX: 0000000000000000 RBX: ffff8abdf2b5d898 RCX: > 0000000000000040 > [ 904.196306] [ C33] RDX: 0000000000000814 RSI: ffff8abdf2b5d800 RDI: > 0000000000000814 > [ 904.196308] [ C33] RBP: 0000000000000002 R08: ffffffffa9dff860 R09: > 0000000000000007 > [ 904.196309] [ C33] R10: 000000e65239d580 R11: 071c71c71c71c71c R12: > ffffffffa9dff860 > [ 904.196311] [ C33] R13: ffffffffa9dff948 R14: 0000000000000002 R15: > 0000000000000000 > [ 904.196313] [ C33] FS: 0000000000000000(0000) > GS:ffff8aadcf680000(0000) knlGS:0000000000000000 > [ 904.196316] [ C33] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 904.196318] [ C33] CR2: 00005632ce239000 CR3: 0000003944f72004 CR4: > 0000000000770ef0 > [ 904.196320] [ C33] PKRU: 55555554 > [ 904.196322] [ C33] Call Trace: > [ 904.196324] [ C33] <TASK> > [ 904.196326] [ C33] acpi_idle_do_entry+0x22/0x50 > [ 904.196336] [ C33] acpi_idle_enter+0x7b/0xd0 > [ 904.196340] [ C33] cpuidle_enter_state+0x79/0x420 > [ 904.196345] [ C33] cpuidle_enter+0x2d/0x40 > [ 904.196352] [ C33] do_idle+0x176/0x1c0 > [ 904.196358] [ C33] cpu_startup_entry+0x29/0x30 > [ 904.196362] [ C33] start_secondary+0xf7/0x100 > [ 904.196366] [ C33] common_startup_64+0x13e/0x141 > [ 904.196374] [ C33] </TASK> > [ 904.196377] [ C33] Kernel panic - not syncing: Hard LOCKUP > [ 904.196379] [ C33] CPU: 33 UID: 0 PID: 0 Comm: swapper/33 Kdump: > loaded Tainted: G O 6.12.34-cloudflare-2025.6.9 #1 > [ 904.196383] [ C33] Tainted: [O]=OOT_MODULE > [ 904.196384] [ C33] Hardware name: GIGABYTE > R162-Z12-CD-G11P5/MZ12-HD4-CD, BIOS M10-sig 02/17/2025 > [ 904.196385] [ C33] Call Trace: > [ 904.196387] [ C33] <NMI> > [ 904.196389] [ C33] dump_stack_lvl+0x4b/0x70 > [ 904.196394] [ C33] panic+0x106/0x2c4 > [ 904.196401] [ C33] nmi_panic.cold+0xc/0xc > [ 904.196404] [ C33] watchdog_hardlockup_check.cold+0xc6/0xe8 > [ 904.196409] [ C33] __perf_event_overflow+0x15a/0x450 > [ 904.196416] [ C33] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 904.196421] [ C33] x86_pmu_handle_irq+0x18a/0x1c0 > [ 904.196436] [ C33] ? set_pte_vaddr+0x40/0x50 > [ 904.196439] [ C33] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 904.196442] [ C33] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 904.196445] [ C33] ? native_set_fixmap+0x63/0xb0 > [ 904.196448] [ C33] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 904.196451] [ C33] ? ghes_copy_tofrom_phys+0x7a/0x100 > [ 904.196457] [ C33] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 904.196460] [ C33] ? __ghes_peek_estatus.isra.0+0x49/0xa0 > [ 904.196465] [ C33] amd_pmu_handle_irq+0x4b/0xc0 > [ 904.196469] [ C33] perf_event_nmi_handler+0x2a/0x50 > [ 904.196473] [ C33] nmi_handle.part.0+0x59/0x110 > [ 904.196479] [ C33] default_do_nmi+0x127/0x180 > [ 904.196483] [ C33] exc_nmi+0x103/0x180 > [ 904.196486] [ C33] end_repeat_nmi+0xf/0x53 > [ 904.196489] [ C33] RIP: 0010:io_idle+0x3/0x30 > [ 904.196493] [ C33] Code: 8b 00 a8 08 75 07 e8 2c e4 ff ff 90 fa e9 c0 > b3 1a 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 89 fa > ec <48> 8b 05 96 42 d4 01 a9 00 00 00 80 75 11 80 3d 4a 42 d4 01 00 75 > [ 904.196495] [ C33] RSP: 0018:ffff9afa88307e70 EFLAGS: 00000093 > [ 904.196497] [ C33] RAX: 0000000000000000 RBX: ffff8abdf2b5d898 RCX: > 0000000000000040 > [ 904.196499] [ C33] RDX: 0000000000000814 RSI: ffff8abdf2b5d800 RDI: > 0000000000000814 > [ 904.196501] [ C33] RBP: 0000000000000002 R08: ffffffffa9dff860 R09: > 0000000000000007 > [ 904.196502] [ C33] R10: 000000e65239d580 R11: 071c71c71c71c71c R12: > ffffffffa9dff860 > [ 904.196504] [ C33] R13: ffffffffa9dff948 R14: 0000000000000002 R15: > 0000000000000000 > [ 904.196510] [ C33] ? io_idle+0x3/0x30 > [ 904.196515] [ C33] ? io_idle+0x3/0x30 > [ 904.196519] [ C33] </NMI> > [ 904.196520] [ C33] <TASK> > [ 904.196521] [ C33] acpi_idle_do_entry+0x22/0x50 > [ 904.196526] [ C33] acpi_idle_enter+0x7b/0xd0 > [ 904.196529] [ C33] cpuidle_enter_state+0x79/0x420 > [ 904.196535] [ C33] cpuidle_enter+0x2d/0x40 > [ 904.196539] [ C33] do_idle+0x176/0x1c0 > [ 904.196544] [ C33] cpu_startup_entry+0x29/0x30 > [ 904.196548] [ C33] start_secondary+0xf7/0x100 > [ 904.196552] [ C33] common_startup_64+0x13e/0x141 > [ 904.196559] [ C33] </TASK> > > Best, Fred _______________________________________________ Openipmi-developer mailing list Openipmi-developer@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openipmi-developer
