emulate_umip_insn(9)

💅 emulate_umip_insn(9) — the kernel API manual, bestie edition

okay so we're in the Kernel API Manual, section 9, and today's main character is emulate_umip_insn ✨

🌸 NAME 🌸

emulate_umip_insn — literally emulates UMIP instructions and hands back dummy values 🫶

✨ SYNOPSIS ✨

int emulate_umip_insn (struct insn *insn , int umip_inst , unsigned char
       *data , int *data_size , bool x86_64 );

🎀 ARGUMENTS 🎀

• insn — the instruction structure, operands and all 💅
• umip_inst — a constant that says which instruction we're emulating, iykyk
• data — the buffer where the dummy result gets stashed 🍓
• data_size — how big the emulated result is
• x86_64 — true if the process is 64-bit, false otherwise

💖 DESCRIPTION 💖

so the whole vibe: emulate an instruction that's protected by UMIP and provide a dummy result. the emulation's result gets saved in data. the size of the results depends on both the instruction and the type of operand — register vs memory address, they're not the same bestie 😭 the size of the result gets updated in data_size.

⚠️ heads up: the caller is responsible for providing a data buffer of at least UMIP_GDT_IDT_BASE_SIZE + UMIP_GDT_IDT_LIMIT_SIZE bytes. no cap, that's on you 🫵

returns 0 on success, -EINVAL on error while emulating 💀

🔥 SEE ALSO 🔥

• Kernel file ./arch/x86/kernel/umip.c
• umip_printk(9)
• identify_insn(9)
• force_sig_info_umip_fault(9)
• fixup_umip_exception(9)

and that's the whole page, bestie 🧚 this came straight out of ./arch/x86/kernel, dated October 2026, and it signs off as emulate_umip_insn(9) — periodt 👑