x86/split lock detection

Running remake 4.3 (4.3+dbg-1.5+dfsg-1) on Ubuntu 22.04 triggers Linux kernel warnings:

[ +19,619040] x86/split lock detection: #DB: remake/737636 took a bus_lock trap at address: 0x5555555645d6
[  +0,118315] x86/split lock detection: #DB: remake/737639 took a bus_lock trap at address: 0x7ffff7b26840
[  +0,005202] x86/split lock detection: #DB: remake/737644 took a bus_lock trap at address: 0x7ffff7b26840
[  +0,004291] x86/split lock detection: #DB: remake/737648 took a bus_lock trap at address: 0x7ffff7b26840
[  +0,002163] x86/split lock detection: #DB: remake/737650 took a bus_lock trap at address: 0x7ffff7b26840
[  +0,002555] x86/split lock detection: #DB: remake/737652 took a bus_lock trap at address: 0x7ffff7b26840
[  +0,012782] x86/split lock detection: #DB: remake/737665 took a bus_lock trap at address: 0x7ffff7b26840
[  +0,019462] x86/split lock detection: #DB: remake/737685 took a bus_lock trap at address: 0x7ffff7b26840

See https://lwn.net/Articles/911219/ for some background.

Sadly I cannot pinpoint exactly which atomic action triggers the warning. I'll try running with split_lock_detect=fatal after the next reboot to get remake killed SIGBUS and using gdb to find the exact location

No source file, test, or exact atomic operation is identified in the report. Reproduce on Ubuntu 22.04 with split_lock_detect=fatal, then use gdb to locate the SIGBUS-triggering operation; done means identifying the cause of the kernel warnings and documenting or correcting it.