kunit_activate_static_stub(9)

💅 kunit_activate_static_stub (9) — from the Kernel API Manual, bestie ✨

okay so. this is a page from the Kernel API Manual and honestly it's giving "tiny header file, huge power" energy. let's get into it 🫶

---

✨ NAME ✨

kunit_activate_static_stub — replace a function using static stubs. that's it. that's the whole vibe. 🔥

---

✨ SYNOPSIS ✨

kunit_activate_static_stub (test , real_fn_addr , replacement_addr );

three args, no notes, slay 💅

---

✨ ARGUMENTS ✨

• test — a pointer to the struct kunit test context for the current test. like, the test you're literally in right now. main character energy 👑
• real_fn_addr — the address of the function you wanna replace. the og, the original, the one getting swapped out 🙈
• replacement_addr — the address of the function you're replacing it with. the understudy that's about to eat 🍓

---

✨ DESCRIPTION ✨

when it's activated, calls to real_fn_addr from within this test — even if they're called indirectly — will instead call replacement_addr. sneak attack. ninja swap. no cap, that's the whole trick 🧚

⚠️ important caveat bestie, don't skip this: the function pointed to by real_fn_addr must begin with the static stub prologue in KUNIT_STATIC_STUB_REDIRECT for this to work. no prologue, no redirect. that's the deal 💀

also, real_fn_addr and replacement_addr must have the same type. matching types only, mismatches are not it 😭

and when you're done being dramatic, the redirection can be disabled again with kunit_deactivate_static_stub. cleanup era 🌸

---

✨ SEE ALSO ✨

• the kernel file ./include/kunit/static_stub.h
• KUNIT_STATIC_STUB_REDIRECT(9)
• kunit_deactivate_static_stub(9)

iykyk 👀

---

and that's the page!! this masterpiece lives in ./include/kunit and the version/date stamp on it is October 2026 — so yeah, mark your calendars, bestie 🎀💖