Re: BUG: sleeping function called from invalid context


Geoffroy Van Cutsem
 

Hi Christoph,

 

I’m not an expert on kernel BUGs either, but it does look indeed like it’s related to XRDP (it’s mentioned in the trace so your observation seems very correct). Could you try to run the very same kernel that you use in the Service VM, but without ACRN? I would like to see if this could be a generic issue with that kernel, or if it’s also somehow related to ACRN.

 

Thanks,

Geoffroy

 

From: acrn-users@... <acrn-users@...> On Behalf Of c.susen@...
Sent: Wednesday, November 17, 2021 10:41 am
To: acrn-users@...
Subject: [acrn-users] BUG: sleeping function called from invalid context

 

Hi all,

 

I'm just getting started with ACRN and am encountering the problem that BUG messages appear regularly on the screen of my service VM and also in the dmesg output. Unfortunately, I am not deep enough in the subject matter to understand the output of dmesg. So I would be very grateful if someone could give me a hint what could be wrong with my setup.

 

I use Ubuntu 20.04.3 as service OS and ACRN hypervisor and kernel v2.6. I followed the getting started guide at https://projectacrn.github.io/2.6/getting-started/getting-started.html and just launch a single user VM with Ubuntu 20.04.3 and a passthrough network interface card. However, the problem appears also when the user VM is not launched. When I use the standard kernel that comes with Ubuntu, the problem does not appear.

 

To be able to work on the machine from home, I use SSH and XRDP to log in to the service VM and also the user VM. I have the feeling that the bug message is related to the start of a new XRDP session. Whenever I disconnect and reconnect with remote desktop, a new entry with the bug appears in the dmesg output. After a reboot of the service VM and when just using SSH to connect, the dmesg output looks fine. 

 

Here, the corresponding excerpt from the dmesg output:

[Mi Nov 17 10:19:10 2021] BUG: sleeping function called from invalid context at mm/page_alloc.c:4897

[Mi Nov 17 10:19:10 2021] in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 3199, name: xrdp

[Mi Nov 17 10:19:10 2021] Preemption disabled at:

[Mi Nov 17 10:19:10 2021] [<ffffffffb0267d5f>] __swp_swapcount+0x4f/0x90

[Mi Nov 17 10:19:10 2021] CPU: 1 PID: 3199 Comm: xrdp Tainted: G     U  W         5.10.52-acrn-sos-00001-gbf7f88634a83 #1

[Mi Nov 17 10:19:10 2021] Hardware name: Dell Inc. OptiPlex 5070/0XJ5V0, BIOS 1.0.3 05/30/2019

[Mi Nov 17 10:19:10 2021] Call Trace:

[Mi Nov 17 10:19:10 2021]  dump_stack+0x7d/0x9f

[Mi Nov 17 10:19:10 2021]  ? __swp_swapcount+0x4f/0x90

[Mi Nov 17 10:19:10 2021]  ___might_sleep.cold+0xd3/0xe4

[Mi Nov 17 10:19:10 2021]  __might_sleep+0x4b/0x80

[Mi Nov 17 10:19:10 2021]  __alloc_pages_nodemask+0x206/0x330

[Mi Nov 17 10:19:10 2021]  __read_swap_cache_async+0xd8/0x220

[Mi Nov 17 10:19:10 2021]  swapin_readahead+0x274/0x400

[Mi Nov 17 10:19:10 2021]  do_swap_page+0x160/0x870

[Mi Nov 17 10:19:10 2021]  ? handle_mm_fault+0x629/0x16a0

[Mi Nov 17 10:19:10 2021]  ? do_user_addr_fault+0x20e/0x3f0

[Mi Nov 17 10:19:10 2021]  handle_mm_fault+0xd37/0x16a0

[Mi Nov 17 10:19:10 2021]  do_user_addr_fault+0x20e/0x3f0

[Mi Nov 17 10:19:10 2021]  exc_page_fault+0x54/0x130

[Mi Nov 17 10:19:10 2021]  ? asm_exc_page_fault+0x8/0x30

[Mi Nov 17 10:19:10 2021]  asm_exc_page_fault+0x1e/0x30

[Mi Nov 17 10:19:10 2021] RIP: 0033:0x55bdba616fae

[Mi Nov 17 10:19:10 2021] Code: 8b 3d c6 80 02 00 e8 11 e2 ff ff 48 83 c4 08 4c 89 e0 5b 5d 41 5c 41 5d c3 0f 1f 00 f3 0f 1e fa 41 54 55 48 81 ec 18 01 00 00 <48> 8b 3d 93 80 02 00 64 48 8b 04 25 28 00 00 00 48 89 84 24 08 01

[Mi Nov 17 10:19:10 2021] RSP: 002b:00007ffd365c8d30 EFLAGS: 00010206

[Mi Nov 17 10:19:10 2021] RAX: 0000000000000000 RBX: 000055bdbb34cf00 RCX: 0000000000000000

[Mi Nov 17 10:19:10 2021] RDX: 00007ffd365c8d90 RSI: 00007ffd365c8d90 RDI: 00007ff0e1ebb506

[Mi Nov 17 10:19:10 2021] RBP: 000055bdbb351350 R08: 0000000000000000 R09: 00007ff0e1c742d0

[Mi Nov 17 10:19:10 2021] R10: 00007ff0e185d740 R11: 0000000000000246 R12: 00007ffd365c8e80

[Mi Nov 17 10:19:10 2021] R13: 00007ffd365c8e7c R14: 00000000000a0009 R15: 0000000000000000

 

Thanks in advance for your help!

 

Best regards,

Christoph

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