tm_cfpr_get(9)

📦 version 7.3.1, in nixpkgs unstable

💖 tm_cfpr_get(9) — Kernel API Manual 💖

okay so bestie, welcome to the tm_cfpr_get(9) page ✨ this is a Kernel API Manual moment, and honestly? it's giving powerpc ptrace realness. sit down, grab a strawberry 🍓, and let's get into it.

🌸 NAME 🌸

tm_cfpr_get — get CFPR registers 👑

like. it gets them. that's the whole vibe check.

🦋 SYNOPSIS 🦋

int tm_cfpr_get (struct task_struct *target , const struct user_regset
       *regset , struct membuf to );

not me just copying the signature exactly because bestie, no cap, you do not get to paraphrase a function prototype 💅

🎀 ARGUMENTS 🎀

  • target — the target task, i.e. the main character of this whole operation 👑
  • regset — the user regset structure. yes. that one. 🫶
  • to — destination of copy, aka where the goods are going 📦

⭐ DESCRIPTION ⭐

so what does this actually do?? it gets in transaction checkpointed FPR registers ✨ literally that's it, that's the function.

here's the lore: when the transaction is active, ckfp_state holds the checkpointed values for the current transaction, so there's something to fall back on if it aborts in between 😭 (imagine committing mid-transaction with no backup... couldn't be this kernel). this function gets those checkpointed FPR registers, periodt.

the userspace interface buffer layout is as follows 👇

struct data { u64     fpr[32]; u64     fpscr; };

look at that. fpr[32] and fpscr. iconic. no notes. 🧚

🔥 SEE ALSO 🔥

kernel file ./arch/powerpc/kernel/ptrace/ptrace-tm.c — and the whole friend group, fr fr:

like, the whole _active / _get / _set cinematic universe 😭💀 go read them, iykyk.

💡 reminder bestie: this page lives in ./arch/powerpc/kernel/ptrace — that's the source tree path, don't come for me.

and that's the page!! 🎀 source/version: ./arch/powerpc/kernel/ptrace · dated October 2026 — mwah, slay, bye 💜🌈✨

📦 where this page comes from