HI steve I have installed the openstack on the server, and create & destroy some virtual machines. Then I left it to run for about 2 days without do nothing. The problem happened I don't know what proc file it read by now, since when I found the problem on Monday, the kernel have already been hang-up. Thanks Feng >-----Original Message----- >From: Steven Rostedt [mailto:rostedt@xxxxxxxxxxx] >Sent: Monday, June 26, 2017 10:24 PM >To: Feng Feng24 Liu >Cc: Sebastian Andrzej Siewior; Mike Galbraith; linux-kernel@xxxxxxxxxxxxxxx; >linux-rt-users@xxxxxxxxxxxxxxx; tmac@xxxxxx >Subject: Re: BUG: unable to handle kernel NULL pointer dereference at >0000000000000038 !//RE: kernel BUG at kernel/locking/rtmutex.c:1027 > >On Mon, 26 Jun 2017 06:33:29 +0000 >Feng Feng24 Liu <liufeng24@xxxxxxxxxx> wrote: > >> Hi, dear RT experts >> Thanks a lot! >> I update our kernel to 4.4.70-rt83 as your suggestion. The incorrect deadlock >detection problem has been fixed in this version. >> >> But I found there is another BUG in 4.4.70-rt83, which can cause the system >hang-up >> The BUG is: "BUG: unable to handle kernel NULL pointer dereference at >0000000000000038" >> Following is the kernel log >> ---------------------------------------------------------------------- >> --------------------------------------------------------- >> <4>Jun 23 21:54:53 node-1 kernel: [ 1377.160768] handler405 (21385) >> used greatest stack depth: 11336 bytes left <4>Jun 23 21:54:53 node-1 >> kernel: [ 1377.161073] handler403 (21383) used greatest stack depth: >> 11000 bytes left <1>Jun 24 10:01:19 node-1 kernel: [44959.446196] BUG: >> unable to handle kernel NULL pointer dereference at 0000000000000038 >> <1>Jun 24 10:01:19 node-1 kernel: [44959.446203] IP: >> [<ffffffff810a2cb4>] __try_to_take_rt_mutex+0x34/0x160 <4>Jun 24 >> 10:01:19 node-1 kernel: [44959.446205] PGD 1ea8056067 PUD 1e71e4a067 >> PMD 0 <4>Jun 24 10:01:19 node-1 kernel: [44959.446206] Oops: 0000 [#1] >> PREEMPT SMP <4>Jun 24 10:01:19 node-1 kernel: [44959.446230] Modules >> linked in: xt_nat xt_REDIRECT nf_nat_redirect xt_mark ip6table_raw >> ip6table_mangle ip6table_filter ip6_tables xt_CHECKSUM xt_connmar k >> iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat >> nf_nat_ipv4 nf_nat veth 8021q garp mrp xt_tcpudp xt_conntrack >> iptable_raw xt_CT xt_comment iptable_filter xt_multiport ope nvswitch >> intel_rapl iosf_mbi intel_powerclamp coretemp kvm_intel kvm irqbypass >> crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel >> aes_x86_64 glue_helper lrw ablk_helper cryptd in put_leds led_class >> sb_edac edac_core lpc_ich mfd_core mei_me ioatdma mei dca shpchp >> ipmi_devintf ipmi_si ipmi_msghandler mxm_wmi wmi acpi_pad >> acpi_power_meter tpm_tis nf_conntrack_ipv6 nf_d >> efrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 ip_tables x_tables raid1 >> megaraid_sas <4>Jun 24 10:01:19 node-1 kernel: [44959.446233] CPU: 17 >> PID: 1738811 Comm: ip Not tainted 4.4.70-thinkcloud-nfv #1 <4>Jun 24 >> 10:01:19 node-1 kernel: [44959.446234] Hardware name: LENOVO System >> x3650 M5: -[8871AC1]-/01GR174, BIOS -[TCE124M-2.10]- 06/23/2016 <4>Jun >> 24 10:01:19 node-1 kernel: [44959.446235] task: ffff881cda2c27c0 ti: >> ffff881ea0538000 task.ti: ffff881ea0538000 <4>Jun 24 10:01:19 node-1 >> kernel: [44959.446236] RIP: 0010:[<ffffffff810a2cb4>] >> [<ffffffff810a2cb4>] __try_to_take_rt_mutex+0x34/0x160 <4>Jun 24 >> 10:01:19 node-1 kernel: [44959.446237] RSP: 0018:ffff881ea053bb50 >> EFLAGS: 00010082 <4>Jun 24 10:01:19 node-1 kernel: [44959.446238] RAX: >> 0000000000000000 RBX: ffff881f805416a8 RCX: 0000000000000000 <4>Jun 24 >> 10:01:19 node-1 kernel: [44959.446238] RDX: ffff881ea053bb98 RSI: >> ffff881cda2c27c0 RDI: ffff881f805416a8 <4>Jun 24 10:01:19 node-1 >> kernel: [44959.446239] RBP: ffff881ea053bb60 R08: 0000000000000001 >> R09: 0000000000000002 <4>Jun 24 10:01:19 node-1 kernel: [44959.446239] >> R10: 0000000000000a01 R11: 0000000000000001 R12: ffff881cda2c27c0 <4>Jun 24 >10:01:19 node-1 kernel: [44959.446240] R13: ffff881cda2c27c0 R14: >0000000000000202 R15: ffff881f6b0c27c0 <4>Jun 24 10:01:19 node-1 kernel: >[44959.446240] FS: 00007f28be315740(0000) GS:ffff88205f8c0000(0000) >knlGS:0000000000000000 <4>Jun 24 10:01:19 node-1 kernel: [44959.446241] CS: >0010 DS: 0000 ES: 0000 CR0: 0000000080050033 <4>Jun 24 10:01:19 node-1 kernel: >[44959.446241] CR2: 0000000000000038 CR3: 0000001e9e479000 CR4: >00000000003406e0 <4>Jun 24 10:01:19 node-1 kernel: [44959.446242] DR0: >0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 <4>Jun 24 >10:01:19 node-1 kernel: [44959.446242] DR3: 0000000000000000 DR6: >00000000fffe0ff0 DR7: 0000000000000400 <4>Jun 24 10:01:19 node-1 kernel: >[44959.446243] Stack: >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446244] ffff881f805416a8 >> ffff881ea053bb98 ffff881ea053bc28 ffffffff81a8f03d <4>Jun 24 10:01:19 >> node-1 kernel: [44959.446245] ffff881ea053c000 01ff881ea053bb90 >> ffff881cda2c27c0 ffff881f6b0c27c1 <4>Jun 24 10:01:19 node-1 kernel: >[44959.446246] ffff881cda2c2eb0 0000000000000001 0000000000000000 >0000000000000000 <4>Jun 24 10:01:19 node-1 kernel: [44959.446246] Call Trace: >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446252] [<ffffffff81a8f03d>] >> rt_spin_lock_slowlock+0x13d/0x390 <4>Jun 24 10:01:19 node-1 kernel: >> [44959.446255] [<ffffffff81a903bf>] rt_spin_lock+0x1f/0x30 <4>Jun 24 >> 10:01:19 node-1 kernel: [44959.446260] [<ffffffff8141757f>] >> lockref_get_not_dead+0xf/0x50 <4>Jun 24 10:01:19 node-1 kernel: >> [44959.446263] [<ffffffff811e0a01>] ns_get_path+0x61/0x1d0 > >Hmm, this is in the filesystem code. What were you doing when this happened? > > >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446268] [<ffffffff8121eea9>] >> proc_ns_follow_link+0x89/0xa0 > >Do you know what proc file it was reading? > >-- Steve > >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446273] [<ffffffff811c93a3>] >> ? touch_atime+0x23/0xa0 <4>Jun 24 10:01:19 node-1 kernel: >> [44959.446277] [<ffffffff811b89d8>] trailing_symlink+0x208/0x270 >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446279] [<ffffffff811bb267>] >> path_openat+0x2b7/0x12b0 <4>Jun 24 10:01:19 node-1 kernel: >> [44959.446286] [<ffffffff811a1c75>] ? >> mem_cgroup_end_page_stat+0x25/0x50 >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446287] [<ffffffff811bd2ce>] >> do_filp_open+0x7e/0xd0 <4>Jun 24 10:01:19 node-1 kernel: >> [44959.446288] [<ffffffff81a90453>] ? rt_spin_unlock+0x13/0x20 <4>Jun >> 24 10:01:19 node-1 kernel: [44959.446290] [<ffffffff811ca9d5>] ? >> __alloc_fd+0xc5/0x180 <4>Jun 24 10:01:19 node-1 kernel: [44959.446292] >> [<ffffffff811ac9a8>] do_sys_open+0x128/0x210 <4>Jun 24 10:01:19 node-1 >> kernel: [44959.446296] [<ffffffff811460ea>] ? >> __context_tracking_enter+0x8a/0x160 >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446297] [<ffffffff811acaae>] >> SyS_open+0x1e/0x20 <4>Jun 24 10:01:19 node-1 kernel: [44959.446298] >> [<ffffffff81a9086e>] entry_SYSCALL_64_fastpath+0x12/0x71 >> <4>Jun 24 10:01:19 node-1 kernel: [44959.446308] Code: 89 e5 41 54 53 >> 48 83 4f 18 01 48 89 fb 4c 8b 47 18 49 f7 c0 fe ff ff ff 74 05 5b 41 >> 5c 5d c3 48 85 d2 49 89 f4 74 1d 48 8b 4f 10 <48> 3b 79 38 0f 85 0c 01 >> 00 00 48 39 ca 75 e0 48 89 d6 e8 75 fd <1>Jun 24 10:01:19 node-1 >> kernel: [44959.446309] RIP [<ffffffff810a2cb4>] >> __try_to_take_rt_mutex+0x34/0x160 <4>Jun 24 10:01:19 node-1 kernel: >> [44959.446310] RSP <ffff881ea053bb50> <4>Jun 24 10:01:19 node-1 kernel: >[44959.446310] CR2: 0000000000000038 <4>Jun 24 10:01:19 node-1 kernel: >[44963.688055] ---[ end trace 0000000000000002 ]--- <3>Jun 24 10:12:32 node-1 >kernel: [45615.758301] INFO: rcu_preempt detected stalls on CPUs/tasks: >> <3>Jun 24 10:12:32 node-1 kernel: [45615.758308] 4-...: (1 GPs behind) >idle=c77/140000000000000/0 softirq=0/0 fqs=200736 >> <3>Jun 24 10:12:32 node-1 kernel: [45615.758311] (detected by 27, >t=651052 jiffies, g=9051323, c=9051322, q=514190) >> <4>Jun 24 10:12:32 node-1 kernel: [45615.758320] ffff881e9b82bce8 >> ffff881e9b82bd08 ffffffff810856e3 ffff881e9b078a38 <4>Jun 24 10:12:32 >> node-1 kernel: [45615.758321] ffff881e9b82bd20 ffffffff810856e3 >> ffff881f805416a8 ffff881e9b82bd40 <4>Jun 24 10:12:32 node-1 kernel: >[45615.758322] ffffffff81a900bb ffff881f805416a8 ffff881e9b82bd78 >ffff881e9b82be08 <4>Jun 24 10:12:32 node-1 kernel: [45615.758322] Call Trace: >> <4>Jun 24 10:12:32 node-1 kernel: [45615.758332] [<ffffffff810856e3>] >> ? preempt_count_add+0xa3/0xc0 <4>Jun 24 10:12:32 node-1 kernel: >> [45615.758333] [<ffffffff810856e3>] ? preempt_count_add+0xa3/0xc0 >> <4>Jun 24 10:12:32 node-1 kernel: [45615.758338] [<ffffffff81a900bb>] >> ? _raw_spin_lock_irqsave+0x4b/0x50 <4>Jun 24 10:12:32 node-1 kernel: >> [45615.758339] [<ffffffff81a8ef5f>] ? >> rt_spin_lock_slowlock+0x5f/0x390 <4>Jun 24 10:12:32 node-1 kernel: >> [45615.758341] [<ffffffff81a903bf>] ? rt_spin_lock+0x1f/0x30 <4>Jun >> 24 10:12:32 node-1 kernel: [45615.758347] [<ffffffff811c42ce>] ? >> dput+0xce/0x270 <4>Jun 24 10:12:32 node-1 kernel: [45615.758349] >> [<ffffffff811af00a>] ? __fput+0x16a/0x1e0 <4>Jun 24 10:12:32 node-1 >> kernel: [45615.758350] [<ffffffff811af0be>] ? ____fput+0xe/0x10 >> <4>Jun 24 10:12:32 node-1 kernel: [45615.758352] [<ffffffff8107e7e6>] >> ? task_work_run+0x86/0xb0 <4>Jun 24 10:12:32 node-1 kernel: >> [45615.758355] [<ffffffff8105c784>] ? exit_to_usermode_loop+0xa2/0xd7 >> <4>Jun 24 10:12:32 node-1 kernel: [45615.758358] [<ffffffff81001b1a>] >> ? syscall_return_slowpath+0x8a/0xb0 <4>Jun 24 10:12:32 node-1 kernel: >> [45615.758359] [<ffffffff81a909cc>] ? int_ret_from_sys_call+0x25/0x8f >> <5>Jun 24 10:12:32 node-1 kernel: [45633.758592] megaraid_sas >> 0000:10:00.0: [ 0]waiting for 2 commands to complete for scsi0 -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
