[BUG] dm-crypt broken after 2632e2521769 ("arm64: fpsimd: Implement lazy restore for kernel mode FPSIMD")

[Johannes Nixdorf]

I noticed frequent FS corruption on my M1 MacBook running Linux after
the Asahi Linux Kernel was updated to 6.9.x (from 6.6.x).

A git bisect pointed me to 2632e2521769 ("arm64: fpsimd: Implement lazy
restore for kernel mode FPSIMD").

This was reproduced with fio's examples/basic-verify.fio (1GB of writing
was not reliably, 10GB triggered it reliably) on vanilla kernels and
happens on any storage backend behind dm-crypt.

I was advised to report it here on IRC.

This was independently described in [1].

Regards,
Johannes Nixdorf

[1]: https://github.com/tpwrules/nixos-apple-silicon/issues/200