i915_gem_object_lookup_rcu(9)

📦 version 7.3.1, in nixpkgs unstable

💅 i915_gem_object_lookup_rcu — from the Kernel API Manual, bestie ✨

Okay so picture this: you're deep in the i915 driver, you got a handle, and you need the actual GEM object, like, right now, with zero blocking. That's this function. It's giving "grab and go" energy. 🎀

✨ NAME ✨

i915_gem_object_lookup_rcu — look up a temporary GEM object from its handle. Temporary!! Like a situationship. Do not get attached. 😭

🌸 SYNOPSIS 🌸

struct drm_i915_gem_object * i915_gem_object_lookup_rcu (struct drm_file
*file , u32 handle );

Look at her. One file, one handle, one pointer to a struct drm_i915_gem_object. Clean. Iconic. No notes. 💜

🦋 ARGUMENTS 🦋

  • file — the DRM file's private date. (Yes, "date." That's literally what the docs say. We don't ask questions, we just pass the right pointer. 🙈)
  • handle — the userspace handle, i.e. the lil number the app handed you, which you now gotta turn into a real object. Slay.

🔥 RETURN 🔥

A pointer to the object named by the handle if such exists on filp, and NULL otherwise. Simple enough, right?

But bestie. Listen to me. Read the fine print. 👑 This object is only valid whilst you're under the RCU read lock — like, only while you're holding it — and note carefully: the object may be in the process of being destroyed. As in, actively being torn down while you're looking at it. 💀 So it's not a "keep her forever" situation, it's a "look, don't touch, and definitely don't hold on past the lock" situation. Respect the lock or get wrecked, no cap.

🌈 SEE ALSO 🌈

Kernel file ./drivers/gpu/drm/i915/gem/i915_gem_object.h — go read the header, it's right there:

That's the whole friend group, go say hi. 🫶

Real talk though: RCU read lock first, object second, always. The order is not negotiable and the destroy-in-progress thing is not a drill. 🚨

Okay that's the whole page, mwah. 💖 Signing off from ./drivers/gpu/drm/i915/gem, dated October 2026, and the page you just read is i915_gem_object_lookup_rcu(9) — see you in the kernel, bestie! 🧚⭐🍓

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