"bus error" when generating public key

[Christian Hewitt]

I’m working to add WireGuard support to an embedded distro that runs on a mix of x86 and ARM hardware. I’m using 4.19.7 as the kernel base, cross compiling using a well proven toolchain and build-system. The kernel defconfig can be seen here:

https://github.com/chewitt/LibreELEC.tv/blob/amlogic/projects/Amlogic/linux/linux.aarch64.conf

I see no compile errors when building the kernel module or wireguard tools. The kernel module loads without errors and ‘wg’ can generate private and preshared keys, but when creating a public key from the private key ‘wg pubkey < /path/to/privatekey' fails with “Bus error” and no key is generated.

dmesg from the device after the failure: http://ix.io/1vrb

modinfo wireguard
filename:       /lib/modules/4.19.7/kernel/net/wireguard/wireguard.ko
alias:          net-pf-16-proto-16-family-wireguard
alias:          rtnl-link-wireguard
version:        0.0.20181119
author:         Jason A. Donenfeld <Jason at zx2c4.com>
description:    WireGuard secure network tunnel
license:        GPL v2
srcversion:     1CFE12F8E5CF00DB842FD50
depends:        ipv6,udp_tunnel,ip6_udp_tunnel
intree:         Y
name:           wireguard
vermagic:       4.19.7 SMP preempt mod_unload aarch64

ldd /usr/bin/wg
	libc.so.6 => /usr/lib/libc.so.6 (0xf7771000)
	/lib/ld-linux-armhf.so.3 => /usr/lib/ld-linux-armhf.so.3 (0xf78ad000)

I’m not a coding developer, but I’m able to follow instructions to a reasonable level if there is some kind of debugging or additional output that would be useful.

Can you spot the problem? Any suggestions?

Christian