Seen on a Cavium CRB1S: [ 1823.116031] Unable to handle kernel read from unreadable memory at virtual address 00000038 [ 1823.124479] user pgtable: 4k pages, 48-bit VAs, pgd = ffff801f4bf00000 [ 1823.131068] [0000000000000038] *pgd=0000000000000000 [ 1823.136080] Internal error: Oops: 96000004 [#1] SMP [ 1823.141002] Modules linked in: nls_iso8859_1 i2c_thunderx thunderx_zip thunderx_edac i2c_smbus shpchp cavium_rng_vf cavi um_rng gpio_keys ipmi_ssif ipmi_devintf ipmi_msghandler uio_pdrv_genirq uio ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp l ibiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor as ync_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear nicvf nicpf ast i2c_algo_bit ttm drm_kms_helper syscopyarea sysf illrect aes_ce_blk sysimgblt aes_ce_cipher fb_sys_fops crc32_ce crct10dif_ce drm ghash_ce sha2_ce sha1_ce ahci libahci thun der_bgx thunder_xcv mdio_thunder thunderx_mmc mdio_cavium aes_neon_bs aes_neon_blk crypto_simd cryptd [ 1823.204136] CPU: 30 PID: 0 Comm: swapper/30 Not tainted 4.13.0-36-generic #40~16.04.1-Ubuntu [ 1823.212655] Hardware name: Cavium ThunderX CRB/To be filled by O.E.M., BIOS 5.11 12/12/2012 [ 1823.221085] task: ffff801f7320bc00 task.stack: ffff801f73210000 [ 1823.227067] PC is at set_next_entity+0x28/0x5e8 [ 1823.231640] LR is at pick_next_task_fair+0xa0/0x580 [ 1823.236561] pc : [] lr : [] pstate: 604001c5 [ 1823.244026] sp : ffff801f73213dc0 [ 1823.247368] x29: ffff801f73213dc0 x28: ffff801f7ca19800 [ 1823.252731] x27: ffff000008a76aac x26: ffff801f7ca19868 [ 1823.258093] x25: ffff801f7320c2c0 x24: ffff0000093c8000 [ 1823.263455] x23: 0000000000000000 x22: ffff000008fe1000 [ 1823.268817] x21: ffff801f7ca19868 x20: ffff801f7ca19868 [ 1823.274178] x19: 0000000000000000 x18: 0000ffffca622758 [ 1823.279541] x17: 00000000002711a2 x16: 0000000000000000 [ 1823.284903] x15: 00003dc0f68eb41e x14: 0001318c81308142 [ 1823.290266] x13: 00000003e8000000 x12: 00000000000000b4 [ 1823.295628] x11: 0000000000000000 x10: 00000000000000b4 [ 1823.300990] x9 : ffff000008aa5c98 x8 : ffff801f7320c760 [ 1823.306353] x7 : 0000000000000020 x6 : 003541e45d3fef78 [ 1823.311715] x5 : 0000000000000018 x4 : ffff000008118e88 [ 1823.317077] x3 : ffff000008aa5a70 x2 : ffff00000810cb18 [ 1823.324394] x1 : 0000000000000000 x0 : ffff000008118f28 [ 1823.331704] Process swapper/30 (pid: 0, stack limit = 0xffff801f73210000) [ 1823.340536] Stack: (0xffff801f73213dc0 to 0xffff801f73214000) [ 1823.348292] 3dc0: ffff801f73213e10 ffff000008118f28 0000000000000000 ffff801f7ca19868 [ 1823.358135] 3de0: ffff801f73213f28 ffff000008fe1000 0000000000000000 ffff0000093c8000 [ 1823.367943] 3e00: ffff801f7320c2c0 ffff801f7ca19868 ffff801f73213eb0 ffff000008a75f98 [ 1823.377737] 3e20: ffff801f7ca19800 ffff801f7320bc00 ffff801f73213f28 ffff000008fe1000 [ 1823.387523] 3e40: 0000000000000000 ffff0000093c8000 ffff801f7320c2c0 ffff801f7ca19800 [ 1823.397271] 3e60: ffff000008a76aac ffff0000093c8000 ffff801f7ca19868 ffff00000814a4e4 [ 1823.406965] 3e80: ffff801f73213eb0 ffff000008aa5bb0 ffff801f7320bc00 ffff801f73213f28 [ 1823.416614] 3ea0: ffff801f7ca19800 0000000000040d00 ffff801f73213f40 ffff000008a76aac [ 1823.426211] 3ec0: ffff801f7320bc00 ffff0000093c9658 ffff0000093c9000 ffff000008ff1348 [ 1823.435758] 3ee0: 0000000000000000 0000000000000000 ffff801f7320bc00 0000000000000000 [ 1823.445266] 3f00: 0000000000000000 0000000000000000 ffff801f73213f60 ffff000008aa5a70 [ 1823.454714] 3f20: ffff000008fe1000 ffff0000093c9658 ffff000000000000 0000000000040d00 [ 1823.464120] 3f40: ffff801f73213f60 ffff000008123238 ffff000008fe1000 0000000000040d00 [ 1823.473470] 3f60: ffff801f73213fb0 ffff000008123534 0000000000000084 000000000000001e [ 1823.482770] 3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1823.492031] 3fa0: 0000000000000000 ffff000008123524 ffff801f73213fd0 ffff000008092308 [ 1823.501281] 3fc0: 000000000000001e ffffffffffffffff 0000000000000000 00000000018831c4 [ 1823.510542] 3fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1823.519768] Call trace: [ 1823.523564] Exception stack(0xffff801f73213bd0 to 0xffff801f73213d00) [ 1823.531424] 3bc0: 0000000000000000 0001000000000000 [ 1823.540734] 3be0: 000000000243d000 ffff00000810e310 00000000604001c5 0000000000000001 [ 1823.550059] 3c00: 0000000000000000 0000000000000000 ffff801f73dbe880 ffff801f73dbd900 [ 1823.559408] 3c20: 0000000000000033 000000000000c000 0000000000000001 0000000000000017 [ 1823.568763] 3c40: 0000000000000017 0000000000000017 0000000000000017 0000000000000400 [ 1823.578098] 3c60: 0000000000000097 0000000000000001 0000000000000001 0000000000000000 [ 1823.587422] 3c80: 0000000000000000 0000000000040d00 ffff000008118f28 0000000000000000 [ 1823.596740] 3ca0: ffff00000810cb18 ffff000008aa5a70 ffff000008118e88 0000000000000018 [ 1823.606057] 3cc0: 003541e45d3fef78 0000000000000020 ffff801f7320c760 ffff000008aa5c98 [ 1823.615418] 3ce0: 00000000000000b4 0000000000000000 00000000000000b4 00000003e8000000 [ 1823.624791] [] set_next_entity+0x28/0x5e8 [ 1823.631915] [] pick_next_task_fair+0xa0/0x580 [ 1823.639406] [] __schedule+0x130/0x8b0 [ 1823.646207] [] schedule_idle+0x2c/0x48 [ 1823.653104] [] do_idle+0xb8/0x1e0 [ 1823.659536] [] cpu_startup_entry+0x2c/0x30 [ 1823.666729] [] secondary_start_kernel+0x108/0x118 [ 1823.674507] [<00000000018831c4>] 0x18831c4 [ 1823.680110] Code: aa0003f5 aa1e03e0 aa0103f3 d503201f (b9403a60) [ 1823.687766] ---[ end trace 331ab1a448238eaa ]--- [ 1823.693924] Kernel panic - not syncing: Attempted to kill the idle task! [ 1823.702219] SMP: stopping secondary CPUs [ 1824.796049] SMP: failed to stop secondary CPUs 10,30 [ 1824.802592] Unable to handle kernel read from unreadable memory at virtual address 00000000 [ 1824.812593] user pgtable: 4k pages, 48-bit VAs, pgd = ffff801f4bf00000 [ 1824.820785] [0000000000000000] *pgd=0000000000000000 [ 1824.827405] Internal error: Oops: 86000004 [#2] SMP [ 1824.833951] Modules linked in: nls_iso8859_1 i2c_thunderx thunderx_zip thunderx_edac i2c_smbus shpchp cavium_rng_vf cavi um_rng gpio_keys ipmi_ssif ipmi_devintf ipmi_msghandler uio_pdrv_genirq uio ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp l ibiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor as ync_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear nicvf nicpf ast i2c_algo_bit ttm drm_kms_helper syscopyarea sysf illrect aes_ce_blk sysimgblt aes_ce_cipher fb_sys_fops crc32_ce crct10dif_ce drm ghash_ce sha2_ce sha1_ce ahci libahci thun der_bgx thunder_xcv mdio_thunder thunderx_mmc mdio_cavium aes_neon_bs aes_neon_blk crypto_simd cryptd [ 1824.911861] CPU: 30 PID: 0 Comm: swapper/30 Tainted: G D 4.13.0-36-generic #40~16.04.1-Ubuntu [ 1824.925653] Hardware name: Cavium ThunderX CRB/To be filled by O.E.M., BIOS 5.11 12/12/2012 [ 1824.936146] task: ffff801f7320bc00 task.stack: ffff801f73210000 [ 1824.944207] PC is at 0x0 [ 1824.948879] LR is at panic_event+0x84/0x110 [ipmi_msghandler] [ 1824.956803] pc : [<0000000000000000>] lr : [] pstate: 204001c5 [ 1824.966439] sp : ffff801f732138b0 [ 1824.971992] x29: ffff801f732138b0 x28: ffff801f7320bc00 [ 1824.979561] x27: ffff000008a76aac x26: ffff801f7ca19868 [ 1824.987103] x25: ffff801f7320c2c0 x24: ffff801f7320bc00 [ 1824.994623] x23: 0000000000000000 x22: ffff00000955cbd8 [ 1825.002107] x21: 0000000000000001 x20: ffff0000019e5080 [ 1825.009575] x19: ffff801f7140c000 x18: ffff0000093c8c08 [ 1825.017034] x17: 0000000000000001 x16: 0000000000000007 [ 1825.024493] x15: ffff00008956e757 x14: 0000000000000001 [ 1825.031943] x13: 0000000000000020 x12: ffff801f7269e520 [ 1825.039396] x11: 00000000ffffffff x10: 0000000000000001 [ 1825.046838] x9 : ffff000014bcdba0 x8 : ffff000008b21a08 [ 1825.054265] x7 : 0000000000000001 x6 : 000000000000050d [ 1825.061675] x5 : ffff0000019e5160 x4 : 0000000000000000 [ 1825.069054] x3 : ffff0000019de8b8 x2 : 0000000000000000 [ 1825.076389] x1 : 0000000000000001 x0 : ffff801f27eed000 [ 1825.083697] Process swapper/30 (pid: 0, stack limit = 0xffff801f73210000) [ 1825.092518] Stack: (0xffff801f732138b0 to 0xffff801f73214000) [ 1825.100269] 38a0: ffff801f732138e0 ffff0000080fca1c [ 1825.110125] 38c0: ffff000009402760 00000000fffffffe 0000000000000000 0000000000000100 [ 1825.119984] 38e0: ffff801f73213920 ffff0000080fcb7c ffff00000955cfd8 0000000000000000 [ 1825.129845] 3900: ffff00000955cbd8 ffff000008d33800 00000000000001c0 ffff000008d33800 [ 1825.139672] 3920: ffff801f73213950 ffff0000080d2e38 ffff00000955c000 ffff00000955cbd8 [ 1825.149449] 3940: 0000000000000000 0000000000040d00 ffff801f73213a30 ffff0000080d7ffc [ 1825.159185] 3960: 000000000000000b ffff801f7320bc00 0000000000000001 ffff000008d2b0e8 [ 1825.168875] 3980: 00000000000001c0 ffff801f7320bc00 ffff801f7320c2c0 ffff801f7ca19868 [ 1825.178511] 39a0: ffff801f73213a30 ffff801f73213a30 ffff801f732139f0 00000000ffffffc8 [ 1825.188101] 39c0: ffff801f7320bc00 ffff801f73213a30 ffff801f73213a30 ffff801f732139f0 [ 1825.197633] 39e0: 00000000ffffffc8 0000000000040d00 ffff801f7320bc00 0000000000000000 [ 1825.207130] 3a00: ffff801f7320bc00 00000000ffffffff 0000000000000000 0000000000000001 [ 1825.216594] 3a20: 000000000000050a 0000000000000001 ffff801f73213ab0 ffff00000808c130 [ 1825.226037] 3a40: ffff00000954f000 ffff801f73213c90 0000000000000001 ffff000008d2b0e8 [ 1825.235452] 3a60: 00000000000001c0 ffff801f7320bc00 ffff801f7320c2c0 ffff801f7ca19868 [ 1825.244836] 3a80: ffff000008a76aac ffff801f7320bc00 ffff801f73213ab0 ffff00000808c084 [ 1825.254205] 3aa0: ffff00000954f000 0000000000040d00 ffff801f73213af0 ffff00000809f48c [ 1825.263562] 3ac0: 0000000096000004 0000000000000021 ffff801f73213c90 0000000000000038 [ 1825.272888] 3ae0: 0000000000000000 0000000000000025 ffff801f73213b20 ffff000008a7cf70 [ 1825.282180] 3b00: ffff801f73213c90 ffff801f7320bc00 0000000096000004 0000000000000038 [ 1825.291503] 3b20: ffff801f73213b90 ffff000008a7d16c 0000000000000038 0000000096000004 [ 1825.300829] 3b40: ffff801f73213c90 0000000000000038 ffff801f73213c90 0000000000000025 [ 1825.310168] 3b60: ffff801f7320c2c0 ffff801f7ca19868 ffff000008a76aac ffff801f7320bc00 [ 1825.319526] 3b80: 00000000000001c0 ffff0000093c9000 ffff801f73213bc0 ffff000008081244 [ 1825.328915] 3ba0: ffff000008a97218 ffff0000093c8000 0000000096000004 ffff0000081352e4 [ 1825.338313] 3bc0: ffff801f73213dc0 ffff000008082f38 0000000000000000 0001000000000000 [ 1825.347717] 3be0: 000000000243d000 ffff00000810e310 00000000604001c5 0000000000000001 [ 1825.357136] 3c00: 0000000000000000 0000000000000000 ffff801f73dbe880 ffff801f73dbd900 [ 1825.366570] 3c20: 0000000000000033 000000000000c000 0000000000000001 0000000000000017 [ 1825.376013] 3c40: 0000000000000017 0000000000000017 0000000000000017 0000000000000400 [ 1825.385442] 3c60: 0000000000000097 0000000000000001 0000000000000001 0000000000000000 [ 1825.394855] 3c80: 0000000000000000 0000000000040d00 ffff000008118f28 0000000000000000 [ 1825.404272] 3ca0: ffff00000810cb18 ffff000008aa5a70 ffff000008118e88 0000000000000018 [ 1825.413707] 3cc0: 003541e45d3fef78 0000000000000020 ffff801f7320c760 ffff000008aa5c98 [ 1825.423164] 3ce0: 00000000000000b4 0000000000000000 00000000000000b4 00000003e8000000 [ 1825.432609] 3d00: 0001318c81308142 00003dc0f68eb41e 0000000000000000 00000000002711a2 [ 1825.442035] 3d20: 0000ffffca622758 0000000000000000 ffff801f7ca19868 ffff801f7ca19868 [ 1825.451452] 3d40: ffff000008fe1000 0000000000000000 ffff0000093c8000 ffff801f7320c2c0 [ 1825.460847] 3d60: ffff801f7ca19868 ffff000008a76aac ffff801f7ca19800 ffff801f73213dc0 [ 1825.470244] 3d80: ffff000008118f28 ffff801f73213dc0 ffff00000810e310 00000000604001c5 [ 1825.479645] 3da0: ffff801f7ca1d280 053d35967b5b3cc0 ffffffffffffffff ffff00000816545c [ 1825.489059] 3dc0: ffff801f73213e10 ffff000008118f28 0000000000000000 ffff801f7ca19868 [ 1825.498477] 3de0: ffff801f73213f28 ffff000008fe1000 0000000000000000 ffff0000093c8000 [ 1825.507882] 3e00: ffff801f7320c2c0 ffff801f7ca19868 ffff801f73213eb0 ffff000008a75f98 [ 1825.517299] 3e20: ffff801f7ca19800 ffff801f7320bc00 ffff801f73213f28 ffff000008fe1000 [ 1825.526702] 3e40: 0000000000000000 ffff0000093c8000 ffff801f7320c2c0 ffff801f7ca19800 [ 1825.536122] 3e60: ffff000008a76aac ffff0000093c8000 ffff801f7ca19868 ffff00000814a4e4 [ 1825.545523] 3e80: ffff801f73213eb0 ffff000008aa5bb0 ffff801f7320bc00 ffff801f73213f28 [ 1825.554920] 3ea0: ffff801f7ca19800 0000000000040d00 ffff801f73213f40 ffff000008a76aac [ 1825.564302] 3ec0: ffff801f7320bc00 ffff0000093c9658 ffff0000093c9000 ffff000008ff1348 [ 1825.573671] 3ee0: 0000000000000000 0000000000000000 ffff801f7320bc00 0000000000000000 [ 1825.583046] 3f00: 0000000000000000 0000000000000000 ffff801f73213f60 ffff000008aa5a70 [ 1825.592410] 3f20: ffff000008fe1000 ffff0000093c9658 ffff000000000000 0000000000040d00 [ 1825.601787] 3f40: ffff801f73213f60 ffff000008123238 ffff000008fe1000 0000000000040d00 [ 1825.611157] 3f60: ffff801f73213fb0 ffff000008123534 0000000000000084 000000000000001e [ 1825.620526] 3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1825.629870] 3fa0: 0000000000000000 ffff000008123524 ffff801f73213fd0 ffff000008092308 [ 1825.639228] 3fc0: 000000000000001e ffffffffffffffff 0000000000000000 00000000018831c4 [ 1825.648591] 3fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 1825.657933] Call trace: [ 1825.661858] Exception stack(0xffff801f732136c0 to 0xffff801f732137f0) [ 1825.669837] 36c0: ffff801f7140c000 0001000000000000 000000000243d000 0000000000000000 [ 1825.679249] 36e0: 00000000204001c5 ffff000008136c1c ffff801f732137e0 ffff000008d2d0d0 [ 1825.688680] 3700: ffff0000093c9658 ffff0000093c8000 00000000000001c0 ffff801f7320bc00 [ 1825.698110] 3720: ffff801f7320c2c0 ffff801f7ca19868 ffff000008a76aac ffff801f7320bc00 [ 1825.707540] 3740: ffff801f732137e0 ffff000008136c1c ffff801f73213840 0000000000000000 [ 1825.716996] 3760: ffff801f732138f0 ffff801f732138f0 ffff801f732138b0 0000000000040d00 [ 1825.726461] 3780: ffff801f27eed000 0000000000000001 0000000000000000 ffff0000019de8b8 [ 1825.735955] 37a0: 0000000000000000 ffff0000019e5160 000000000000050d 0000000000000001 [ 1825.745461] 37c0: ffff000008b21a08 ffff000014bcdba0 0000000000000001 00000000ffffffff [ 1825.754945] 37e0: ffff801f7269e520 0000000000000020 [ 1825.761460] [< (null)>] (null) [ 1825.767801] [] notifier_call_chain+0x5c/0xa0 [ 1825.775268] [] atomic_notifier_call_chain+0x3c/0x50 [ 1825.783352] [] panic+0x15c/0x29c [ 1825.789770] [] do_exit+0x834/0xa38 [ 1825.796341] [] die+0x1b0/0x1c8 [ 1825.802536] [] __do_kernel_fault+0xbc/0x130 [ 1825.809856] [] do_page_fault+0x250/0x3e0 [ 1825.816920] [] do_translation_fault+0x6c/0x7c [ 1825.824410] [] do_mem_abort+0x6c/0xe0 [ 1825.831203] Exception stack(0xffff801f73213bd0 to 0xffff801f73213d00) [ 1825.839239] 3bc0: 0000000000000000 0001000000000000 [ 1825.848713] 3be0: 000000000243d000 ffff00000810e310 00000000604001c5 0000000000000001 [ 1825.858191] 3c00: 0000000000000000 0000000000000000 ffff801f73dbe880 ffff801f73dbd900 [ 1825.867681] 3c20: 0000000000000033 000000000000c000 0000000000000001 0000000000000017 [ 1825.877170] 3c40: 0000000000000017 0000000000000017 0000000000000017 0000000000000400 [ 1825.886628] 3c60: 0000000000000097 0000000000000001 0000000000000001 0000000000000000 [ 1825.896079] 3c80: 0000000000000000 0000000000040d00 ffff000008118f28 0000000000000000 [ 1825.905509] 3ca0: ffff00000810cb18 ffff000008aa5a70 ffff000008118e88 0000000000000018 [ 1825.914942] 3cc0: 003541e45d3fef78 0000000000000020 ffff801f7320c760 ffff000008aa5c98 [ 1825.924403] 3ce0: 00000000000000b4 0000000000000000 00000000000000b4 00000003e8000000 [ 1825.933872] [] el1_da+0x24/0xa0 [ 1825.940210] [] pick_next_task_fair+0xa0/0x580 [ 1825.947770] [] __schedule+0x130/0x8b0 [ 1825.954632] [] schedule_idle+0x2c/0x48 [ 1825.961544] [] do_idle+0xb8/0x1e0 [ 1825.967994] [] cpu_startup_entry+0x2c/0x30 [ 1825.975196] [] secondary_start_kernel+0x108/0x118 [ 1825.982996] [<00000000018831c4>] 0x18831c4 [ 1825.988599] Code: bad PC value [ 1825.993141] ---[ end trace 331ab1a448238eab ]--- [ 1825.999255] Kernel panic - not syncing: Attempted to kill the idle task! [ 1826.007524] SMP: stopping secondary CPUs [ 1827.101309] SMP: failed to stop secondary CPUs 10,30 [ 1827.107810] Kernel Offset: disabled [ 1827.112822] CPU features: 0x101108 [ 1827.117715] Memory Limit: none [ 1827.122259] ---[ end Kernel panic - not syncing: Attempted to kill the idle task!