kernel: dnsmasq[20205]: unhandled level 3 translation fault

[Jack Yaz]

Any ideas? dnsmasq restarted and all OK since.
RT-AC86U
384.7_2

ov  1 22:31:08 kernel: dnsmasq[20205]: unhandled level 3 translation fault (11) at 0x00000000, esr 0x92000007
Nov  1 22:31:08 kernel: pgd = ffffffc004b21000
Nov  1 22:31:08 kernel: [00000000] *pgd=0000000004b00003, *pud=0000000004b00003, *pmd=0000000004afc003, *pte=0000000000000000
Nov  1 22:31:08 kernel: CPU: 0 PID: 20205 Comm: dnsmasq Tainted: P           O    4.1.27 #2
Nov  1 22:31:08 kernel: Hardware name: Broadcom-v8A (DT)
Nov  1 22:31:08 kernel: task: ffffffc01e042a40 ti: ffffffc004bd4000 task.ti: ffffffc004bd4000
Nov  1 22:31:08 kernel: PC is at 0x27fd4
Nov  1 22:31:08 kernel: LR is at 0x22
Nov  1 22:31:08 kernel: pc : [<0000000000027fd4>] lr : [<0000000000000022>] pstate: 60000010
Nov  1 22:31:08 kernel: sp : 00000000fffcf5a8
Nov  1 22:31:08 kernel: x12: 000000000054f896
Nov  1 22:31:08 kernel: x11: 0000000000000000 x10: 0000000000709cb0
Nov  1 22:31:08 kernel: x9 : 00000000000a9725 x8 : 0000000000000026
Nov  1 22:31:08 kernel: x7 : 00000000000001ff x6 : 0000000000000000
Nov  1 22:31:08 kernel: x5 : 000000000054f870 x4 : 00000000009a7758
Nov  1 22:31:08 kernel: x3 : 0000000000000001 x2 : 0000000000000000
Nov  1 22:31:08 kernel: x1 : 0000000000000000 x0 : 0000000000000000

 

[sfx2000]

armv8 translation bugs like this one generally fall into one of two areas...

1) userland task is trying to write to an address(range) that is marked read-only by another userland task...

or...

2) userland task is trying to write data into memory reserved by the kernel - which to a userland app that memory, again, is read-only...

(sometimes this is also a privilege level escalation thing, but I don't think this applies here, e.g. armv8 trusted vs. untrusted)

@RMerlin could maybe share some more insight...

the HND platform is a hybrid environment - the kernel is 64-bit, but there is still quite a bit of code that is armv7a...

 

[Mutzli]

I got it happening in my RT-AC86U also.

I have the same issue on my RT-AC86U, but not on the RT-AX88U.

 

[RMerlin]

The AC86 crashes are usually from the dcd process, which has been widely documented by now, including in the Changelog...

The original post here was about dnsmasq, which is totally different.

 

[Zork]

Have same issue in AC86, but router seem working as usual.
Firmware 384.12


Jun 23 19:12:38 kernel: dcd[11362]: unhandled level 3 translation fault (11) at 0x00000000, esr 0x92000007
Jun 23 19:12:38 kernel: pgd = ffffffc01484f000
Jun 23 19:12:38 kernel: [00000000] *pgd=0000000002aad003, *pud=0000000002aad003, *pmd=0000000002970003, *pte=0000000000000000
Jun 23 19:12:38 kernel: CPU: 1 PID: 11362 Comm: dcd Tainted: P O 4.1.27 #2
Jun 23 19:12:38 kernel: Hardware name: Broadcom-v8A (DT)
Jun 23 19:12:38 kernel: task: ffffffc014ac81c0 ti: ffffffc0028a8000 task.ti: ffffffc0028a8000
Jun 23 19:12:38 kernel: PC is at 0xf6f26f44
Jun 23 19:12:38 kernel: LR is at 0x1dc74
Jun 23 19:12:38 kernel: pc : [<00000000f6f26f44>] lr : [<000000000001dc74>] pstate: 600e0010
Jun 23 19:12:38 kernel: sp : 00000000ffc6c028
Jun 23 19:12:38 kernel: x12: 000000000009ff08

 

[ColinTaylor]

Have same issue in AC86, but router seem working as usual.

So you didn't bother reading the post by RMerlin immediately before yours then?