fixup_pi_owner(9)

✨ fixup_pi_owner ✨

okay bestie, welcome to the Kernel API Manual 💖 this one's a little kernel-side cleanup queen and she's lowkey iconic. let's get into it.

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🌸 NAME 🌸

fixup_pi_owner — post lock pi_state and corner case management 🎀

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🦋 SYNOPSIS 🦋

int fixup_pi_owner (u32 __user *uaddr , struct futex_q *q , int locked );

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💅 ARGUMENTS 💅

• uaddr — the user address of the futex, no cap 📍
• q — a futex_q, which contains pi_state and gives you access to the rt_mutex 🧚
• locked — did the attempt to take the rt_mutex succeed (1) or not (0)? that's the whole vibe check right there 👑

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🔥 DESCRIPTION 🔥

so after you attempt to lock an rt_mutex, this function gets called to clean up the pi_state owner and handle the race conditions that might just let us acquire the lock 😭 literally doing two jobs and serving both.

⚠️ important bestie: this must be called with the hb lock held. not optional, not a suggestion, it's giving mandatory 💀

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⭐ RETURN ⭐

• 1 — success, lock taken 🎉
• 0 — success, lock not taken 🫶
• <0 — on error (-EFAULT) 🙈

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👑 SEE ALSO 👑

• Kernel file ./kernel/futex/pi.c
• futex_lock_pi_atomic(9)

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🌈 and that's the whole page, bestie! this lil slice of kernel API manual energy came from ./kernel/futex and it's dated October 2026 — go off, futex files, periodt 💜