block with lvm2 & cryptsetup (static? (!udev) )

sdauth · Guru Joined: 19 Sep 2018 Posts: 569 Location: Ásgarðr

Hello, an update this morning asks me to disable udev for lvm2 & cryptsetup since I have static enabled for both, lvm2 (static static-libs) cryptsetup (static); why this change ? How to solve that ?

sdauth · Guru Joined: 19 Sep 2018 Posts: 569 Location: Ásgarðr

By the way, I only need static for my initramfs.
So right now I have two option, either :

permanently remove static, static-libs for lvm2 / cryptsetup and copy needed libs to the initramfs
-> it adds 1.3M to the initramfs
Except the initramfs is slightly bigger, this works fine.

or

rebuild temporarily lvm2 & cryptsetup (without udev) before generating the initramfs

Ionen · Developer Joined: 06 Dec 2018 Posts: 2717

I didn't really follow the situation but it sparked from this:

https://github.com/systemd/systemd/issues/20600

Gentoo already barely support static linking, and if upstream doesn't care (closing bug reports and leaving it broken for us to fix) then it seems reasonable to drop.

sdauth · Guru Joined: 19 Sep 2018 Posts: 569 Location: Ásgarðr

Thanks for the link Ionen.
Well.. I will choose the no static lib option. I can afford the bigger initramfs on my desktop. Other option would be to use slashbeast's better-initramfs ( https://github.com/slashbeast/better-initramfs ) to avoid headaches.

ExecutorElassus · Posted: Thu Sep 16, 2021 5:37 pm Post subject:

somebody please explain to me like I'm stupid why this issue affects a system like mine that doesn't have systemd on it at all.

Hu · Moderator Joined: 06 Mar 2007 Posts: 21607

First, the presence of systemd in the cited URL is an unfortunate red herring caused by the systemd project assuming control of the udevd project. The question is not whether your system uses systemd. The question is whether your system uses udevd. Second, the problem is that the systemd-udevd code uses a poorly chosen (excessively generic) name for a symbol, then relies on linker tricks to avoid collisions, instead of marking the symbol as static.[1] Additionally, due to the linker tricks that upstream does use, this problem only impacts people who use static libraries. Various upstreams provide different levels of support for static libraries, but I think it's fair to say that, for most projects, such support tends to be a low priority. The systemd project is a bit surprising in their refusal to apply a simple and targeted fix for a known problem, but it's not uncommon to find projects that have static linking related problems.

[1]: static would only work if the symbol was only used in one translation unit. If it needs to be used across multiple translation units in the udevd project, it cannot be static - but it could be given a better name.

ExecutorElassus · Posted: Fri Sep 17, 2021 3:48 am Post subject:

sounds an awful lot like systemd is pursuing MS's old embrace-extend-extinguish tactics. So I guess I'll be trying to figure out how to use better-initramfs to get my initramfs set up.

(my use-case is that I have / and /usr on LVMs, and thus need to pre-mount them prior to mounting real root)

Cheers,

EE