for_each_insn_prefix(9)

✨ for_each_insn_prefix(9) ✨

okay so bestie, this page is from the Kernel API Manual, and it's literally all about for_each_insn_prefix — the move for iterating over prefixes in an instruction. 💅

🌸 NAME 🌸

for_each_insn_prefix - - Iterate prefixes in the instruction

🎀 SYNOPSIS 🎀

for_each_insn_prefix (insn , prefix );

🦋 ARGUMENTS 🦋

• insn — a pointer to struct insn. yes bestie, that kind of pointer. 🫶
• prefix — the prefix byte. iconic. ✨

💖 DESCRIPTION 💖

So what it does is iterate prefix bytes of the given insn. Each prefix byte is stored in prefix, and the index is stored in idx — and ngl, note that this idx is just a cursor, so do not change it. 😭

⚠️ okay important vibe check: since prefixes.nbytes can be bigger than 4 if some prefixes are repeated, it cannot be used for looping over the prefixes. no cap. 💀

🌈 SEE ALSO 🌈

• Kernel file ./tools/arch/x86/include/asm/insn.h

💌 mwah, this cutie comes from source/version ./tools/arch/x86/include/asm, dated October 2026 — slay, bye bestie! 🎀👑