To be more precise, the first public comment asking to dlopenify lzma was dated 30 Jan by Daan: https://github.com/systemd/systemd/pull/31131#issuecomment-1...

The day after, it was reiterated by Lennart: https://github.com/systemd/systemd/pull/31131#issuecomment-1...

But if you look in the systemd repo there is a TODO file with a section of libraries which needs to be lazy loaded. liblzma was added in this list in June 2020 (https://github.com/systemd/systemd/commit/cdfd853744ee934869...) by Lennart, and removed by me just after that my PR was merged.

But many others followed, like libselinux: https://github.com/systemd/systemd/pull/19997

libqrencode: https://github.com/systemd/systemd/pull/16145

p11kit: https://github.com/systemd/systemd/pull/25771

tpm2-util: https://github.com/systemd/systemd/pull/28333

libiptc: https://github.com/systemd/systemd/pull/29836

libkmod: https://github.com/systemd/systemd/pull/31131

Exactly during the development of the libkmod PR, someone noted that libxz could be lazily loaded too: https://github.com/systemd/systemd/pull/31131#issuecomment-1...

And so I proposed myself to to the job, nothing less, nothing more.

If you look at the code of the other PRs, you see that they are very very similar, there are also macros to easy this task, like DLSYM_FUNCTION()

I'm the author of such PR. My purpose was to trim down the size of the initram files by removing unneeded dependencies.

I couldn't imagine that liblzma had a backdoor.