register_nmi_handler(9)

💖 register_nmi_handler(9) 💖

okay so bestie, welcome to the Kernel API Manual — this page is all about register_nmi_handler and it's lowkey iconic 🫶✨

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🎀 NAME 🎀

register_nmi_handler — Register a handler for a specific NMI type 💅

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✨ SYNOPSIS ✨

register_nmi_handler (t , fn , fg , n , init... );

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🌸 ARGUMENTS 🌸

• t — NMI type, like NMI_LOCAL fr fr.
• fn — the NMI handler itself 👑
• fg — the flags associated with the NMI handler 🚩
• n — name of the NMI handler 🏷️
• init — optional __init* attributes for struct nmiaction ✨

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🦋 DESCRIPTION 🦋

So what it does: it adds the provided handler to the list of handlers for the specified NMI type 🫶 Handlers flagged with NMI_FLAG_FIRST would be executed first — yes, first is first, no cap 💅

Sometimes the source of an NMI can't be reliably determined, which results in an NMI being tagged as "unknown" 😭 When that happens, register an additional handler using the NMI type - NMI_UNKNOWN to handle such cases. The caller would get one last chance to assume responsibility for the NMI 👀🔥

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💀 RETURN 💀

0 on success, or an error code on failure 😭 manifesting zero, but prepare for the error code bestie.

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🌈 SEE ALSO 🌈

• Kernel file ./arch/x86/include/asm/nmi.h enum (anonymous)(9) 👀
• unregister_nmi_handler(9) — the counterpart, obviously 💅

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and yeah, this lil page's source/version is ./arch/x86/include/asm, dated October 2026, and it's serving register_nmi_handler(9) energy — periodt 💖🎀