Symptom
kernel core generated (unexpected crash)
/bootflash/core/kernel.rp_xxxx.core.flat.gz
/bootflash/core/kernel.rp_xxxx.txt
last reload reason:
Last reload reason: LocalSoftADR
kernel trace appears like:
[11786876.018350] BUG: kernel NULL pointer dereference, address: 0000000000000000
[11786876.018360] #PF: supervisor instruction fetch in kernel mode
[11786876.018363] #PF: error_code(0x0010) - not-present page
[11786876.018366] PGD 429f91067 P4D 429f91067 PUD 42ba6a067 PMD 0
[11786876.018372] Oops: 0010 [#1] SMP NOPTI
[11786876.018377] CPU: 6 PID: 21591 Comm: ucode_hqf_worke Kdump: loaded Tainted: G O 5.4.108 #1
[11786876.018384] RIP: 0010:0x0
[11786876.018389] Code: Bad RIP value.
[11786876.018391] RSP: 0000:ffffa700caa57ea8 EFLAGS: 00210202
[11786876.018394] RAX: ffff92d32bb99c80 RBX: ffff92d32b3f1c00 RCX: 0000000000000008
[11786876.018398] RDX: 00000000c2e06b18 RSI: 00000000000000a8 RDI: ffff92d32bb99c80
[11786876.018401] RBP: 0000000000000000 R08: 00000000c2e06af4 R09: 00000000c2e06b18
[11786876.018404] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
[11786876.018408] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[11786876.018412] FS: 0000000000000000(0000) GS:ffff92d36f980000(0063) knlGS:00000000c2e0fb40
[11786876.018415] CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
[11786876.018419] CR2: ffffffffffffffd6 CR3: 000000042a2a0000 CR4: 00000000003406e0
[11786876.018422] Call Trace:
[11786876.018431] ? syscall_trace_enter+0x1c1/0x1ef
[11786876.018436] ? trace_hardirqs_off_caller+0x27/0x45
[11786876.018440] ? tracer_hardirqs_on+0x21/0xf6
[11786876.018443] ? do_int80_syscall_32+0x33/0x65
[11786876.018448] ? entry_INT80_compat+0x87/0xa0
Conditions
platform: C8200-1N-4T
version: 17.6.1a
Router operating mode: Autonomous
no particular trigger found at the moment.
Workaround
No workaround at the moment.
Further Problem Description
There are some events where the reboot is caused by loose DIMM modules in the devices.
Consider to reseat the DIMM memories during a maintenance window and monitor the device.
If suspecting this issue might be affecting your device, consider to collect "show tech" file and extract the files created during the reboot events.
