__cond_releases(9)

📦 version 7.3.1, in nixpkgs unstable

💅 __cond_releases — the "bestie this function might drop the lock" attribute 🎀

okay so real talk, this one lives in the Kernel API Manual and it's genuinely such a specific little icon. it's a function attribute — not a function you call, not a macro you invoke, just a lil tag you slap on a function declaration so the analysis tooling knows what's up. and what's up is: this function conditionally releases a context lock exclusively. that's the whole vibe check. 🦋

✨ SYNOPSIS ✨

__cond_releases (ret , x );

like, that's literally it. two args, both mandatory, no cap. 💅

🌸 ARGUMENTS 🌸

  • ret — the abstract value that the function returns if the context lock releases. think of it as the "when does the lock actually get dropped" signal — it's an abstract value, not a runtime value, so don't go trying to print it or anything 😭
  • x — the context lock instance pointer. this is the actual lock we're talking about. point it at your lock, bestie 🫶

💖 DESCRIPTION 💖

so this attribute is declaring that the function conditionally releases the given context lock instance x — and it does it exclusively. exclusive release, nobody else gets a turn, periodt.

here's the important part though: the associated context(s) must be active on entry. like, the lock has to already be held when your function gets called, otherwise the whole premise is off and the analysis is gonna be confused. so, active on entry. mandatory. no exceptions. ⭐

and then the function's return value ret is what tells you when the context lock is released. so it's not "it always releases" and it's not "it never releases" — it's "it releases when the return value matches what ret says". that's the conditional part, iykyk. 🔥

ret may be one of:

  • true
  • false
  • nonzero
  • 0
  • nonnull
  • NULL

that's the whole list, don't invent your own. 💀

👑 NOTE 👑

okay this is the part where the tooling gets a little real with you:

clang does not have a native attribute for this. like, it just doesn't exist upstream.

so instead you implement it as an unconditional release plus a conditional acquire for the inverted condition — which is semantically equivalent. so: always release, then conditionally re-acquire on the flip side of the condition. mathematically the same thing, just spelled differently. it's giving "we work with what we have" energy and honestly, it ate. 🌈

🧚 SEE ALSO 🧚

all the siblings and cousins, in the order the page gives them, because we do not skip anyone in this friend group 💜

and that's the whole page, bestie — go forth and annotate responsibly 💅✨

this cutie came out of ./include/linux, dated October 2026, and its whole name is __cond_releases(9) — stan forever 🎀🦋💖

📦 where this page comes from