Re: Panic with "Unrecoverable machine check exception"

Hi.

It is likely a hardware failure, unless a false positive. Check last
console logs or better BMC logs for detail.

On Fri, Jun 27, 2025, 16:26 Steve Kargl <sgk@troutmask.apl.washington.edu>
wrote:

> Never seen this type of panic.  I can upload
> core.txt.4 and info.4 to freefall if someone
> wants more details.
>
>
> __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:57
> 57              __asm("movq %%gs:%c1,%0" : "=r" (td)
> (kgdb) #0  __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:57
>         td = <optimized out>
> #1  doadump (textdump=textdump@entry=1)
>     at /usr/src/sys/kern/kern_shutdown.c:399
>         error = 0
>         coredump = <optimized out>
> #2  0xffffffff80676e30 in kern_reboot (howto=260)
>     at /usr/src/sys/kern/kern_shutdown.c:519
>         once = 0
>         __pc = 0x0
> #3  0xffffffff80677367 in vpanic (
>     fmt=0xffffffff80abdb94 "Unrecoverable machine check exception",
>     ap=ap@entry=0xfffffe001c024ed0) at
> /usr/src/sys/kern/kern_shutdown.c:974
>         buf = "Unrecoverable machine check exception", '\000' <repeats 218
> times>
>         __pc = 0x0
>         __pc = 0x0
>         __pc = 0x0
>         other_cpus = {__bits = {251, 0 <repeats 15 times>}}
>         td = 0xfffff80004601000
>         bootopt = <unavailable>
>         newpanic = <optimized out>
> #4  0xffffffff80677193 in panic (fmt=<unavailable>)
>     at /usr/src/sys/kern/kern_shutdown.c:887
>         ap = {{gp_offset = 8, fp_offset = 48,
>             overflow_arg_area = 0xfffffe001c024f00,
>             reg_save_area = 0xfffffe001c024ea0}}
> #5  0xffffffff809d391b in mca_intr () at /usr/src/sys/x86/x86/mca.c:1540
>         recoverable = false
>         mcg_status = <optimized out>
>         count = <optimized out>
>         lmcs = <optimized out>
> #6  <signal handler called>
> No locals.
> #7  mi_switch (flags=flags@entry=262) at
> /usr/src/sys/kern/kern_synch.c:537
>         __pc = 0x0
>         __pc = 0x0
>         __pc = 0x0
>         __pc = 0x0
>         __pc = 0x0
>         td = 0xfffff80004601000
>         new_switchtime = <optimized out>
>         runtime = <optimized out>
> #8  0xffffffff806aaca4 in sched_idletd (dummy=dummy@entry=0x0)
>     at /usr/src/sys/kern/sched_4bsd.c:1688
>         __pc = 0x0
>         stat = <optimized out>
> #9  0xffffffff806324b2 in fork_exit (
>     callout=0xffffffff806aac50 <sched_idletd>, arg=0x0,
>     frame=0xfffffe00d5407f40) at /usr/src/sys/kern/kern_fork.c:1153
>         __pc = 0x0
>         __pc = 0x0
>         td = 0xfffff80004601000
>         p = 0xfffffe00c3002040
>         dtd = <optimized out>
> #10 <signal handler called>
>
>
>
>
>
>
> --
> Steve
>
> --
Alexander Motin