Re: Xen Domu kernel crash at start of boot

[Paul Goyette <paul%whooppee.com@localhost>]

> Stopped in pid 0.15 (system) at ffffffff80205968:       fxsavel

I seem to recall some recent changes related to save/restore of fpu 
state.



On Thu, 21 Jun 2018, Chuck Zmudzinski wrote:

> I am getting a kernel crash almost immediately after booting the current 
> kernel. I am running NetBSD/xen amd64 on a Debian Linux 8.10 DOM0 which uses 
> Xen-4.4. Last week's kernel was good. I built a kernel from a cvs update a 
> couple of days ago and tried it. It crashed. I tried the most recent daily 
> snapshot available from NetBSD daily builds. It crashed too. Here is the 
> information from the console about the daily snapshot kernel that crashed (it 
> was built earlier today):
>
> [   1.0000000] NetBSD 8.99.19 (XEN3_DOMU) #0: Thu Jun 21 11:48:05 UTC 2018
> [   1.0000000] 
> mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/xen/compile/XEN3_DOMU
>
> Here is the information I got from the console about the crash:
>
> [   1.0000000] total memory = 3072 MB
> [   1.0000000] avail memory = 2963 MB
> [   1.0000000] cpu_rng: RDRAND
> [   1.0000000] running cgd selftest aes-xts-256 aes-xts-512 done
> [   1.0000000] mainbus0 (root)
> [   1.0000000] hypervisor0 at mainbus0: Xen version 4.4.1
> [   1.0000000] vcpu0 at hypervisor0
> [   1.0000000] vcpu0: Intel(R) Core(TM) i5-4590S CPU @ 3.00GHz, id 0x306c3
> [   1.0000000] vcpu0: package 0, core 3, smt 0
> [   1.0000000] vcpu1 at hypervisor0
> [   1.0000000] vcpu1: Intel(R) Core(TM) i5-4590S CPU @ 3.00GHz, id 0x306c3
> [   1.0000000] vcpu1: package 0, core 3, smt 0
> [   1.0000000] xenbus0 at hypervisor0: Xen Virtual Bus Interface
> [   1.0000000] xencons0 at hypervisor0: Xen Virtual Console Driver
> [   1.0000030] fatal protection fault in supervisor mode
> [   1.0000030] trap type 4 code 0 rip 0xffffffff80205968 cs 0x10000e030 
> rflags 0x10046 cr2 0 ilevel 0 rsp 0xffffa000a570fbf0
> [   1.0000030] curlwp 0xffffa0000642d4a0 pid 0.15 lowest kstack 
> 0xffffa000a570b2c0
> kernel: protection fault trap, code=0
> Stopped in pid 0.15 (system) at ffffffff80205968:       fxsavel
> ds          0
> es          0
> fs          fd00
> gs          0
> rdi         ffffa000a570fbf8
> rsi         1
> rbp         ffffa000a570fe68
> rbx         0
> rdx         2
> rcx         0
> rax         0
> r8          ffffa00006680000
> r9          cccccccccccccccd
> r10         64
> r11         0
> r12         ffffa000a570fbf8
> r13         1
> r14         0
> r15         0
> rip         ffffffff80205968
> cs          e030
> rflags      10046
> rsp         ffffa000a570fbf0
> ss          e02b
> ffffffff80205968:       fxsavel
> db{1}> bt
> ?() at ffffffff80205968
> ?() at ffffffff802313f0
> ?() at ffffffff8023155e
>
> I could not get any useful info from addr2line. Any ideas why it crashes?
>
> Thanks,
>
> Chuck Zmudzinski
>
>
> !DSPAM:5b2c48e0136191148838969!

+------------------+--------------------------+----------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:          |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee dot com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd dot org |
+------------------+--------------------------+----------------------------+