irqentry_en...om_user_mode(9)

📦 version 7.3.1, in nixpkgs unstable

🎀 irqentry_en...om_user_mode(9) — Kernel API Manual 🎀

okay so bestie, welcome to the Kernel API Manual entry for irqentry_enter_from_user_mode ✨ (yes the header is doing that truncated thing, that's just how it's filed, iykyk 💅). This one is short but she is important — it's the lil pre-game ritual before the irq handler gets to do anything. Let's get into it 🦋

✨ NAME ✨

irqentry_enter_from_user_mode — literally just establishing state before invoking the irq handler 🫶

💫 SYNOPSIS 💫

void irqentry_enter_from_user_mode (struct pt_regs *regs );

🌸 ARGUMENTS 🌸

  • regs — pointer to the current's pt_regs 💖 (yes, "current's" — that's the possessive, no cap, that's what it says)

🔥 DESCRIPTION 🔥

so this one gets invoked from architecure-specific entry code with interrupts disabled, periodt. and here's the vibe check: it can only be called when the interrupt entry came from user mode. no exceptions, bestie 🙈

also the calling code must be non-instrumentable — like, do not instrument her, she's working 😭

but here's the slay: when the function returns, all state is correct and the subsequent functions can be instrumented. the glow-up is real 👑

the function establishes state (lockdep, RCU (context tracking), tracing) — that's the whole bag, she handles it 💅

👑 SEE ALSO 👑

the whole friend group, fr fr 💜:

she lives in ./include/linux, and this edition dropped October 2026 🌈 — that's the footer, and honestly? iconic. go read the source, bestie, it ate 💀💖

okay that's the whole page, ily, go forth and enter from user mode responsibly 🧚‍♀️✨

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