Panic after main-n273387-bb8b3b174118 -> main-n273419-523913c94371

Oddly, this is only on my "build machine" (which runs a GENERIC/amd64
kernel) -- neither of the laptops whined at all.

Copy/paste of the backtrace from serial console:

...
Starting mountd.


Fatal trap 12: page fault while in kernel mode
cpuid = 42; apic id = 2a
fault virtual address   = 0x28
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff80c3a482
stack pointer           = 0x28:0xfffffe01b5f8ea00
frame pointer           = 0x28:0xfffffe01b5f8ea80
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 2241 (mountd)
rdi: fffff8207a989c00 rsi: 0000000000000002 rdx: fffff8207a086330
rcx: 0000000000000000  r8: fffff8207906c740  r9: 0000000000020000
rax: 0000000000000000 rbx: fffffe051ce25000 rbp: fffffe01b5f8ea80
r10: 0000000000000000 r11: 0000000000000001 r12: fffffe01b5f8eb48
r13: fffff820dd5a2e00 r14: fffff8207a989e00 r15: fffff8207a989e00
trap number             = 12
panic: page fault
cpuid = 42
time = 1730638810
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe01b5f8e6d0
vpanic() at vpanic+0x136/frame 0xfffffe01b5f8e800
panic() at panic+0x43/frame 0xfffffe01b5f8e860
trap_fatal() at trap_fatal+0x40b/frame 0xfffffe01b5f8e8c0
trap_pfault() at trap_pfault+0xa0/frame 0xfffffe01b5f8e930
calltrap() at calltrap+0x8/frame 0xfffffe01b5f8e930
--- trap 0xc, rip = 0xffffffff80c3a482, rsp = 0xfffffe01b5f8ea00, rbp = 0xfffffe01b5f8ea80 ---
vfs_export() at vfs_export+0x7a2/frame 0xfffffe01b5f8ea80
vfs_domount_update() at vfs_domount_update+0x7da/frame 0xfffffe01b5f8ec10
vfs_domount() at vfs_domount+0x27f/frame 0xfffffe01b5f8ed40
vfs_donmount() at vfs_donmount+0x904/frame 0xfffffe01b5f8edd0
sys_nmount() at sys_nmount+0x60/frame 0xfffffe01b5f8ee00
amd64_syscall() at amd64_syscall+0x158/frame 0xfffffe01b5f8ef30
fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe01b5f8ef30
--- syscall (378, FreeBSD ELF64, nmount), rip = 0x27c44b7fe0aa, rsp = 0x27c449448528, rbp = 0x27c449449090 ---
KDB: enter: panic
[ thread pid 2241 tid 102819 ]
Stopped at      kdb_enter+0x33: movq    $0,0x1056222(%rip)
db>


One possibly-salient point about the build machine -- it's 32 cores;
64 threads.  Which is considerably more potential for multiprocessing
than the laptops.  It's also an AMD (Epyc) CPU (vs. the Intel CPUs
in the laptops).

The machine would normally be powered off for the rest of the day
after this reboot, so if there's something to be gained by poking
at it, I will happily accept clues & report results.

For additional information (such as a copy of dmesg.boot from yesterday),
please see the "freebeast head" links at
https://www.catwhisker.org/~david/FreeBSD/history/

Thanks!

Peace,
david
-- 
David H. Wolfskill                              david@catwhisker.org
One can learn a lot about someone by noting what is considered "a joke."

See https://www.catwhisker.org/~david/publickey.gpg for my public key.