binder_get_...node_olocked(9)

📦 version 7.3.1, in nixpkgs unstable

💖 binder_get_ref_for_node_olocked(9) 💖

okay so this is a page from the Kernel API Manual and bestie, it's literally about getting the ref that goes with a given node. lock in, we're doing this 🫶

✨ NAME ✨

binder_get_ref_for_node_olocked — get the ref associated with given node

🌸 SYNOPSIS 🌸

struct binder_ref * binder_get_ref_for_node_olocked (struct binder_proc
*proc , struct binder_node *node , struct binder_ref *new_ref );

like, that's the whole signature, no cap. three args, one struct pointer coming back at you 💅

🎀 ARGUMENTS 🎀

  • proc — the binder_proc that owns the ref. it's giving "this is my ref, i own it" energy 👑
  • node — the binder_node of target. the thing we're actually looking for, the main character fr
  • new_ref — a newly allocated binder_ref that's gonna get initialized, or NULL. your call, bestie 🙈

🦋 DESCRIPTION 🦋

so first thing it does: it looks up the ref for the given node, and if it exists? it just returns it. easy. slay. ✨

but if it doesn't exist and the caller was nice enough to hand over a newly allocated ref, then it initializes the fields of that newly allocated ref and inserts it into the given proc rb_trees and the node refs list. two places, one insert, iconic behaviour honestly 🔥

⭐ RETURN ⭐

it returns the ref for node. 👑

but here's the plot twist — and this is important, ngl — it is possible that another thread allocated/initialized the ref first. in that case, the returned ref would be different than the passed-in new_ref.

⚠️ and in that case, new_ref must be kfree'd by the caller. no leaking, we don't do that here 💀 please free your refs bestie 😭

🌈 SEE ALSO 🌈

Kernel file ./drivers/android/binder.c — and now the whole friend group, in the order they were introduced 🫶:

anyway that's the whole page 💜 love that for us. this one lives over in ./drivers/android and the version/date stamp says October 2026 — so yeah, future vibes only 🧚✨ bye bestie, go free your new_ref 🍓💅

📦 where this page comes from