On Thu, 15 Jul 2021, Igor Raits wrote: > Hi everyone again, > > I've been trying to reproduce this issue but still can't find a consistent > pattern. > > However, it did happen once more and this time on 5.13.1: Thanks for the updates, Igor. I have to admit that what you have reported confirms the suspicion that it's a bug introduced by one of my "stable" patches in 5.12.14 (which are also in 5.13): nothing else between 5.12.12 and 5.12.14 seems likely to be relevant. But I've gone back and forth and not been able to spot the problem. Please would you send (either privately to me, or to the list) your 5.13.1 kernel's .config, and disassembly of pmd_migration_entry_wait() from its vmlinux (with line numbers if available; or just send the whole vmlinux if that's easier, and I'll disassemble). I am hoping that the disassembly, together with the register contents that you've shown, will help guide towards an answer. Thanks, Hugh > > [ 222.068216] ------------[ cut here ]------------ > [ 222.072884] kernel BUG at include/linux/swapops.h:204! > [ 222.078062] invalid opcode: 0000 [#1] SMP NOPTI > [ 222.082618] CPU: 38 PID: 9828 Comm: rpc-worker Tainted: G E > 5.13.1-1.gdc.el8.x86_64 #1 > [ 222.091894] Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 > Gen10, BIOS U30 05/24/2021 > [ 222.100468] RIP: 0010:pmd_migration_entry_wait+0x132/0x140 > [ 222.105994] Code: 02 00 00 00 5b 4c 89 c7 5d e9 ca c5 f6 ff 48 81 e2 00 > f0 ff ff 48 f7 d2 48 21 c2 89 d1 f7 c2 81 01 00 00 75 80 e9 44 ff ff ff > <0f> 0b 48 8b 2d 65 48 30 01 e9 ef fe ff ff 0f 1f 44 00 00 41 55 48 > [ 222.124878] RSP: 0000:ffffbcfe9eb7bdd8 EFLAGS: 00010246 > [ 222.130134] RAX: 0057ffffc0000000 RBX: ffff9eec4b3cdbf8 RCX: > ffffffffffffffff > [ 222.137309] RDX: 0000000000000000 RSI: ffff9eec4b3cdbf8 RDI: > ffffdf55c52cf368 > [ 222.144485] RBP: ffffdf55c52cf368 R08: ffffdf57428d8080 R09: > 0000000000000000 > [ 222.151661] R10: 0000000000000000 R11: 0000000000000000 R12: > 0000000000000bf8 > [ 222.158837] R13: 0400000000000000 R14: 0400000000000080 R15: > ffff9eec2825b1f8 > [ 222.166015] FS: 00007f6754aeb700(0000) GS:ffff9f49bfd00000(0000) > knlGS:0000000000000000 > [ 222.174153] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 222.179932] CR2: 00007f676ffffd98 CR3: 000000012bf6a002 CR4: > 00000000007726e0 > [ 222.187109] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > 0000000000000000 > [ 222.194283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > 0000000000000400 > [ 222.201457] PKRU: 55555554 > [ 222.204178] Call Trace: > [ 222.206638] __handle_mm_fault+0x5ad/0x6e0 > [ 222.210760] ? sysvec_call_function_single+0xb/0x90 > [ 222.215672] handle_mm_fault+0xc5/0x290 > [ 222.219529] do_user_addr_fault+0x1a9/0x660 > [ 222.223740] ? sched_clock_cpu+0xc/0xa0 > [ 222.227602] exc_page_fault+0x68/0x130 > [ 222.231373] ? asm_exc_page_fault+0x8/0x30 > [ 222.235495] asm_exc_page_fault+0x1e/0x30 > [ 222.239526] RIP: 0033:0x7f67baaed734 > [ 222.243120] Code: 89 08 48 8b 35 dd 3b 21 00 4c 8d 0d d6 3b 21 00 31 c0 > 4c 39 ce 74 73 0f 1f 80 00 00 00 00 48 8d 96 40 fd ff ff 49 39 d2 74 22 > <48> 8b 96 d8 03 00 00 48 01 15 4e 7c 21 00 80 be 50 03 00 00 00 c7 > [ 222.262002] RSP: 002b:00007f6754aea298 EFLAGS: 00010287 > [ 222.267257] RAX: 0000000000000000 RBX: 0000000000000000 RCX: > 0000000000000000 > [ 222.274432] RDX: 00007f676ffff700 RSI: 00007f676ffff9c0 RDI: > 00007f676f7fec10 > [ 222.281609] RBP: 0000000000000001 R08: 00007f676f7fed10 R09: > 00007f67bad012f0 > [ 222.288785] R10: 00007f6754aeb700 R11: 0000000000000202 R12: > 0000000000000001 > [ 222.295961] R13: 0000000000000006 R14: 0000000000000e28 R15: > 00007f674006e1f0 > [ 222.303137] Modules linked in: vhost_net(E) vhost(E) vhost_iotlb(E) > tap(E) tun(E) tcp_diag(E) udp_diag(E) inet_diag(E) netconsole(E) > nf_tables(E) vxlan(E) ip6_udp_tunnel(E) udp_tunnel(E) nfnetlink(E) > binfmt_misc(E) iscsi_tcp(E) libiscsi_tcp(E) 8021q(E) garp(E) mrp(E) > bonding(E) tls(E) vfat(E) fat(E) dm_service_time(E) dm_multipath(E) > rpcrdma(E) sunrpc(E) rdma_ucm(E) ib_srpt(E) ib_isert(E) iscsi_target_mod(E) > target_core_mod(E) ib_iser(E) rdma_cm(E) iw_cm(E) ib_cm(E) libiscsi(E) > intel_rapl_msr(E) intel_rapl_common(E) scsi_transport_iscsi(E) > isst_if_common(E) ipmi_ssif(E) nfit(E) libnvdimm(E) x86_pkg_temp_thermal(E) > intel_powerclamp(E) coretemp(E) kvm_intel(E) kvm(E) irqbypass(E) > crct10dif_pclmul(E) crc32_pclmul(E) ghash_clmulni_intel(E) rapl(E) qedr(E) > mei_me(E) acpi_ipmi(E) ib_uverbs(E) intel_cstate(E) ipmi_si(E) ib_core(E) > ipmi_devintf(E) dm_mod(E) ioatdma(E) ses(E) intel_uncore(E) pcspkr(E) > enclosure(E) mei(E) hpwdt(E) hpilo(E) lpc_ich(E) intel_pch_thermal(E) > dca(E) ipmi_msghandler(E) > [ 222.303181] acpi_power_meter(E) ext4(E) mbcache(E) jbd2(E) sd_mod(E) > t10_pi(E) sg(E) qedf(E) qede(E) libfcoe(E) qed(E) libfc(E) smartpqi(E) > scsi_transport_fc(E) tg3(E) scsi_transport_sas(E) crc8(E) wmi(E) > nf_conntrack(E) libcrc32c(E) crc32c_intel(E) nf_defrag_ipv6(E) > nf_defrag_ipv4(E) br_netfilter(E) bridge(E) stp(E) llc(E) > [ 222.420050] ---[ end trace bcf7b6d1610cc21f ]--- > [ 222.572925] RIP: 0010:pmd_migration_entry_wait+0x132/0x140 > [ 222.578469] Code: 02 00 00 00 5b 4c 89 c7 5d e9 ca c5 f6 ff 48 81 e2 00 > f0 ff ff 48 f7 d2 48 21 c2 89 d1 f7 c2 81 01 00 00 75 80 e9 44 ff ff ff > <0f> 0b 48 8b 2d 65 48 30 01 e9 ef fe ff ff 0f 1f 44 00 00 41 55 48 > [ 222.597359] RSP: 0000:ffffbcfe9eb7bdd8 EFLAGS: 00010246 > [ 222.602620] RAX: 0057ffffc0000000 RBX: ffff9eec4b3cdbf8 RCX: > ffffffffffffffff > [ 222.609807] RDX: 0000000000000000 RSI: ffff9eec4b3cdbf8 RDI: > ffffdf55c52cf368 > [ 222.616990] RBP: ffffdf55c52cf368 R08: ffffdf57428d8080 R09: > 0000000000000000 > [ 222.624177] R10: 0000000000000000 R11: 0000000000000000 R12: > 0000000000000bf8 > [ 222.631361] R13: 0400000000000000 R14: 0400000000000080 R15: > ffff9eec2825b1f8 > [ 222.638548] FS: 00007f6754aeb700(0000) GS:ffff9f49bfd00000(0000) > knlGS:0000000000000000 > [ 222.646694] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 222.652481] CR2: 00007f676ffffd98 CR3: 000000012bf6a002 CR4: > 00000000007726e0 > [ 222.659665] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > 0000000000000000 > [ 222.666850] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > 0000000000000400 > [ 222.674031] PKRU: 55555554 > [ 222.676758] Kernel panic - not syncing: Fatal exception > [ 222.817538] Kernel Offset: 0x16000000 from 0xffffffff81000000 > (relocation range: 0xffffffff80000000-0xffffffffbfffffff) > [ 222.965540] ---[ end Kernel panic - not syncing: Fatal exception ]--- > > On Sun, Jul 11, 2021 at 8:06 AM Igor Raits <igor@xxxxxxxxxxxx> wrote: > > > Hi Hugh, > > > > On Sun, Jul 11, 2021 at 6:17 AM Hugh Dickins <hughd@xxxxxxxxxx> wrote: > > > >> On Sat, 10 Jul 2021, Igor Raits wrote: > >> > >> > Hello, > >> > > >> > I've seen one weird bug on 5.12.14 that happened a couple of times when > >> I > >> > started a bunch of VMs on a server. > >> > >> Would it be possible for you to try the same on a 5.12.13 kernel? > >> Perhaps by reverting the diff between 5.12.13 and 5.12.14 temporarily. > >> Enough to form an impression of whether the issue is new in 5.12.14. > >> > > > > We've been using 5.12.12 for quite some time (~ a month) and I never saw > > it there. > > > > But I have to admit that I don't really have a reproducer. For example, on > > servers where it happened, > > I just rebooted them and panic did not happen anymore (so I saw it only > > only once, > > only on 2 servers out of 32 that we have on 5.12.14). > > > > > >> I ask because 5.12.14 did include several fixes and cleanups from me > >> to page_vma_mapped_walk(), and that is involved in inserting and > >> removing pmd migration entries. I am not aware of introducing any > >> bug there, but your report has got me worried. If it's happening in > >> 5.12.14 but not in 5.12.13, then I must look again at my changes. > >> > >> I don't expect Hillf's patch to help at at all: the pmd_lock() > >> is supposed to be taken by page_vma_mapped_walk(), before > >> set_pmd_migration_entry() and remove_migration_pmd() are called. > >> > >> Thanks, > >> Hugh > >> > >> > > >> > I've briefly googled this problem but could not find any relevant commit > >> > that would fix this issue. > >> > > >> > Do you have any hint how to debug this further or know the fix by any > >> > chance? > >> > > >> > Thanks in advance. Stack trace following: > >> > > >> > [ 376.876610] ------------[ cut here ]------------ > >> > [ 376.881274] kernel BUG at include/linux/swapops.h:204! > >> > [ 376.886455] invalid opcode: 0000 [#1] SMP NOPTI > >> > [ 376.891014] CPU: 40 PID: 11775 Comm: rpc-worker Tainted: G > >> E > >> > 5.12.14-1.gdc.el8.x86_64 #1 > >> > [ 376.900464] Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 > >> > Gen10, BIOS U30 05/24/2021 > >> > [ 376.909038] RIP: 0010:pmd_migration_entry_wait+0x132/0x140 > >> > [ 376.914562] Code: 02 00 00 00 5b 4c 89 c7 5d e9 8a e4 f6 ff 48 81 e2 > >> 00 > >> > f0 ff ff 48 f7 d2 48 21 c2 89 d1 f7 c2 81 01 00 00 75 80 e9 44 ff ff ff > >> > <0f> 0b 48 8b 2d 75 bd 30 01 e9 ef fe ff ff 0f 1f 44 00 00 41 55 48 > >> > [ 376.933443] RSP: 0000:ffffb65a5e1cfdc8 EFLAGS: 00010246 > >> > [ 376.938701] RAX: 0017ffffc0000000 RBX: ffff908b8ecabaf8 RCX: > >> > ffffffffffffffff > >> > [ 376.945878] RDX: 0000000000000000 RSI: ffff908b8ecabaf8 RDI: > >> > fffff497473b2ae8 > >> > [ 376.953055] RBP: fffff497473b2ae8 R08: fffff49747fa8080 R09: > >> > 0000000000000000 > >> > [ 376.960230] R10: 0000000000000000 R11: 0000000000000000 R12: > >> > 0000000000000af8 > >> > [ 376.967407] R13: 0400000000000000 R14: 0400000000000080 R15: > >> > ffff908bbef7b6a8 > >> > [ 376.974582] FS: 00007f5bb1f81700(0000) GS:ffff90e87fd80000(0000) > >> > knlGS:0000000000000000 > >> > [ 376.982718] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >> > [ 376.988497] CR2: 00007f5b2bfffd98 CR3: 00000001f793e006 CR4: > >> > 00000000007726e0 > >> > [ 376.995673] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > >> > 0000000000000000 > >> > [ 377.002849] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > >> > 0000000000000400 > >> > [ 377.010026] PKRU: 55555554 > >> > [ 377.012745] Call Trace: > >> > [ 377.015207] __handle_mm_fault+0x5ad/0x6e0 > >> > [ 377.019335] handle_mm_fault+0xc5/0x290 > >> > [ 377.023194] do_user_addr_fault+0x1cd/0x740 > >> > [ 377.027406] exc_page_fault+0x54/0x110 > >> > [ 377.031182] ? asm_exc_page_fault+0x8/0x30 > >> > [ 377.035307] asm_exc_page_fault+0x1e/0x30 > >> > [ 377.039340] RIP: 0033:0x7f5bb91d6734 > >> > [ 377.042937] Code: 89 08 48 8b 35 dd 3b 21 00 4c 8d 0d d6 3b 21 00 31 > >> c0 > >> > 4c 39 ce 74 73 0f 1f 80 00 00 00 00 48 8d 96 40 fd ff ff 49 39 d2 74 22 > >> > <48> 8b 96 d8 03 00 00 48 01 15 4e 7c 21 00 80 be 50 03 00 00 00 c7 > >> > [ 377.061820] RSP: 002b:00007f5bb1f7ff58 EFLAGS: 00010206 > >> > [ 377.067076] RAX: 0000000000000000 RBX: 0000000000000000 RCX: > >> > 00007f5ba0000020 > >> > [ 377.074255] RDX: 00007f5b2bfff700 RSI: 00007f5b2bfff9c0 RDI: > >> > 0000000000000001 > >> > [ 377.081429] RBP: 0000000000000001 R08: 0000000000000000 R09: > >> > 00007f5bb93ea2f0 > >> > [ 377.088606] R10: 00007f5bb1f81700 R11: 0000000000000202 R12: > >> > 0000000000000001 > >> > [ 377.095782] R13: 0000000000000006 R14: 0000000000000cb4 R15: > >> > 00007f5bb1f801f0 > >> > [ 377.102958] Modules linked in: ebt_arp(E) nft_meta_bridge(E) > >> > ip6_tables(E) xt_CT(E) nf_log_ipv4(E) nf_log_common(E) nft_limit(E) > >> > nft_counter(E) xt_LOG(E) xt_limit(E) xt_mac(E) xt_set(E) xt_multiport(E) > >> > xt_state(E) xt_conntrack(E) xt_comment(E) xt_physdev(E) nft_compat(E) > >> > ip_set_hash_net(E) ip_set(E) vhost_net(E) vhost(E) vhost_iotlb(E) tap(E) > >> > tun(E) tcp_diag(E) udp_diag(E) inet_diag(E) netconsole(E) nf_tables(E) > >> > vxlan(E) ip6_udp_tunnel(E) udp_tunnel(E) nfnetlink(E) binfmt_misc(E) > >> > iscsi_tcp(E) libiscsi_tcp(E) 8021q(E) garp(E) mrp(E) bonding(E) tls(E) > >> > vfat(E) fat(E) dm_service_time(E) dm_multipath(E) rpcrdma(E) sunrpc(E) > >> > rdma_ucm(E) ib_srpt(E) ib_isert(E) iscsi_target_mod(E) > >> target_core_mod(E) > >> > ib_iser(E) rdma_cm(E) iw_cm(E) ib_cm(E) libiscsi(E) > >> scsi_transport_iscsi(E) > >> > intel_rapl_msr(E) qedr(E) intel_rapl_common(E) ib_uverbs(E) > >> > isst_if_common(E) ib_core(E) nfit(E) libnvdimm(E) > >> x86_pkg_temp_thermal(E) > >> > intel_powerclamp(E) coretemp(E) kvm_intel(E) kvm(E) irqbypass(E) > >> > crct10dif_pclmul(E) > >> > [ 377.102999] crc32_pclmul(E) ghash_clmulni_intel(E) rapl(E) > >> > intel_cstate(E) ipmi_ssif(E) acpi_ipmi(E) ipmi_si(E) mei_me(E) > >> ioatdma(E) > >> > ipmi_devintf(E) dm_mod(E) ses(E) intel_uncore(E) pcspkr(E) qede(E) > >> > enclosure(E) tg3(E) mei(E) lpc_ich(E) hpilo(E) hpwdt(E) > >> > intel_pch_thermal(E) dca(E) ipmi_msghandler(E) acpi_power_meter(E) > >> ext4(E) > >> > mbcache(E) jbd2(E) sd_mod(E) t10_pi(E) sg(E) qedf(E) qed(E) crc8(E) > >> > libfcoe(E) libfc(E) smartpqi(E) scsi_transport_fc(E) > >> scsi_transport_sas(E) > >> > wmi(E) nf_conntrack(E) nf_defrag_ipv6(E) libcrc32c(E) crc32c_intel(E) > >> > nf_defrag_ipv4(E) br_netfilter(E) bridge(E) stp(E) llc(E) > >> > [ 377.243468] ---[ end trace 04bce3bb051f7620 ]--- > >> > [ 377.385645] RIP: 0010:pmd_migration_entry_wait+0x132/0x140 > >> > [ 377.391194] Code: 02 00 00 00 5b 4c 89 c7 5d e9 8a e4 f6 ff 48 81 e2 > >> 00 > >> > f0 ff ff 48 f7 d2 48 21 c2 89 d1 f7 c2 81 01 00 00 75 80 e9 44 ff ff ff > >> > <0f> 0b 48 8b 2d 75 bd 30 01 e9 ef fe ff ff 0f 1f 44 00 00 41 55 48 > >> > [ 377.410091] RSP: 0000:ffffb65a5e1cfdc8 EFLAGS: 00010246 > >> > [ 377.415355] RAX: 0017ffffc0000000 RBX: ffff908b8ecabaf8 RCX: > >> > ffffffffffffffff > >> > [ 377.422540] RDX: 0000000000000000 RSI: ffff908b8ecabaf8 RDI: > >> > fffff497473b2ae8 > >> > [ 377.429721] RBP: fffff497473b2ae8 R08: fffff49747fa8080 R09: > >> > 0000000000000000 > >> > [ 377.436902] R10: 0000000000000000 R11: 0000000000000000 R12: > >> > 0000000000000af8 > >> > [ 377.444086] R13: 0400000000000000 R14: 0400000000000080 R15: > >> > ffff908bbef7b6a8 > >> > [ 377.451272] FS: 00007f5bb1f81700(0000) GS:ffff90e87fd80000(0000) > >> > knlGS:0000000000000000 > >> > [ 377.459415] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >> > [ 377.465196] CR2: 00007f5b2bfffd98 CR3: 00000001f793e006 CR4: > >> > 00000000007726e0 > >> > [ 377.472377] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > >> > 0000000000000000 > >> > [ 377.479556] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > >> > 0000000000000400 > >> > [ 377.486738] PKRU: 55555554 > >> > [ 377.489465] Kernel panic - not syncing: Fatal exception > >> > [ 377.573911] Kernel Offset: 0xa000000 from 0xffffffff81000000 > >> (relocation > >> > range: 0xffffffff80000000-0xffffffffbfffffff) > >> > [ 377.716482] ---[ end Kernel panic - not syncing: Fatal exception ]--- > >> > > >> > > > > > > -- > > > > Igor Raits > > > > Sr. SW Engineer > > > > igor@xxxxxxxxxxxx > > > > +420 775 117 817 > > > > Moravske namesti 1007/14 > > > > 602 00 Brno-Veveri, Czech Republic > > > > Twitter <https://twitter.com/gooddata> | Facebook > > <https://www.facebook.com/gooddata> | LinkedIn > > <http://www.linkedin.com/company/gooddata> | Blog > > <http://www.gooddata.com/blog> > > > > > > <https://www.gooddata.com/> > > > > > -- > > Igor Raits > > Sr. SW Engineer > > igor@xxxxxxxxxxxx > > +420 775 117 817 > > Moravske namesti 1007/14 > > 602 00 Brno-Veveri, Czech Republic > > Twitter <https://twitter.com/gooddata> | Facebook > <https://www.facebook.com/gooddata> | LinkedIn > <http://www.linkedin.com/company/gooddata> | Blog > <http://www.gooddata.com/blog> > > > <https://www.gooddata.com/> >
