ampere1 arm64: "panic: Unhandled external data abort" backtrace has been reported

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=290138

has reported a backtrace from the ampere system (ampere1
aarch64 with armv7 support) that has been failing
frequently since back in 2025-Apr. It builds aarch64 and
armv7 quarterly port-packages.

For reference:

Oct 7 23:54:43 ampere1 syslogd: exiting on signal 15
x0: 0x00009c3a6e4d8740
x1: 0xffffa00c9d15b740
x2: 0x0000000000001000
x3: 0x00000000275f3303
x4: 0xd9010000008b0200
x5: 0x000029ef28030907
x6: 0x0000003c02000000
x7: 0x253bb8030907da01
x8: 0x00c7020000000000
x9: 0xe0030907da010000
x10: 0x02000000000029f2
x11: 0x0000000000000001
x12: 0x0000000000000002
x13: 0x0000000000000000
x14: 0x0000000000000001
x15: 0x0000000000000023
x16: 0xffff0000009d89c8 (pagezero_cache + 0x0)
x17: 0x00000000000000fd
x18: 0xffff0002ac43cd70
x19: 0xffff0002ac43cff8
x20: 0x0000000000001000
x21: 0x0000000000000000
x22: 0xffff0002ac43cdf8
x23: 0x0000000000001000
x24: 0xffff0002ac43cdf8
x25: 0x0000000000000000
x26: 0x0000000000000000
x27: 0xffff0002ac43cfe8
x28: 0xffffa00c9d15b000
x29: 0xffff0002ac43cd90
sp: 0xffff0002ac43cd70
lr: 0xffff0000009da9d8 (uiomove_fromphys + 0x15c)
elr: 0xffff0000009aabf4 (by_blocks + 0x0)
spsr: 0x0000000020000005
far: 0x00009c3a6e4d8750
esr: 0x0000000096000410
panic: Unhandled external data abort
cpuid = 19
time = 1760125705
KDB: stack backtrace:
db_trace_self() at db_trace_self
db_trace_self_wrapper() at db_trace_self_wrapper+0x38
vpanic() at vpanic+0x1a0
panic() at panic+0x48
external_abort() at external_abort+0x154
handle_el1h_sync() at handle_el1h_sync+0x18
--- exception, esr 0x96000410
by_blocks() at by_blocks
uiomove_object() at uiomove_object+0x1c4
tmpfs_write() at tmpfs_write+0xf0
VOP_WRITE_APV() at VOP_WRITE_APV+0x98
vn_rdwr() at vn_rdwr+0x2a4
vn_rdwr_inchunks() at vn_rdwr_inchunks+0xa4
core_vn_write() at core_vn_write+0x44
core_output() at core_output+0x124
elf64_coredump() at elf64_coredump+0x57c
coredump_vnode() at coredump_vnode+0xa64
sigexit() at sigexit+0x2d8
postsig() at postsig+0x1d8
ast_sig() at ast_sig+0x1bc
ast_handler() at ast_handler+0x8c
ast() at ast+0x24
handle_el0_sync() at handle_el0_sync+0x64
--- exception, esr 0x92000410
KDB: enter: panic
[ thread pid 64291 tid 507032 ]
Stopped at kdb_enter+0x48: str xzr, [x19, #2048]

db> bt
Tracing pid 64291 tid 507032 td 0xffff00038dad3000
db_trace_self() at db_trace_self
db_stack_trace() at db_stack_trace+0xf0
db_command() at db_command+0x2f4
db_command_loop() at db_command_loop+0x58
db_trap() at db_trap+0x100
kdb_trap() at kdb_trap+0x334
handle_el1h_sync() at handle_el1h_sync+0x18
--- exception, esr 0xf2000000
kdb_enter() at kdb_enter+0x48
vpanic() at vpanic+0x20c
panic() at panic+0x48
external_abort() at external_abort+0x154
handle_el1h_sync() at handle_el1h_sync+0x18
--- exception, esr 0x96000410
by_blocks() at by_blocks
uiomove_object() at uiomove_object+0x1c4
tmpfs_write() at tmpfs_write+0xf0
VOP_WRITE_APV() at VOP_WRITE_APV+0x98
vn_rdwr() at vn_rdwr+0x2a4
vn_rdwr_inchunks() at vn_rdwr_inchunks+0xa4
core_vn_write() at core_vn_write+0x44
core_output() at core_output+0x124
elf64_coredump() at elf64_coredump+0x57c
coredump_vnode() at coredump_vnode+0xa64
sigexit() at sigexit+0x2d8
postsig() at postsig+0x1d8
ast_sig() at ast_sig+0x1bc
ast_handler() at ast_handler+0x8c
ast() at ast+0x24
handle_el0_sync() at handle_el0_sync+0x64
--- exception, esr 0x92000410
db> reboot
===

I provided some summary historical notes in:

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=290138

That includes:

Detail related to the specific backtrace:

. . .
building for: FreeBSD 143arm64-quarterly-job-05 14.3-RELEASE-p4 FreeBSD 14.3-RELEASE-p4 arm64
. . .
Ports top last git commit: 24fedaeb4
. . .
Host OSVERSION: 1600000
Jail OSVERSION: 1403000
. . .

I'm not aware of any way to get the specific
kernel source's git hash from the public logs.


Mark Millard
marklmi at yahoo.com