text_poke_copy(9)

💖 text_poke_copy(9) 💖

okay so bestie, welcome to text_poke_copy(9) from the Kernel API Manual ✨ this one is giving low-level code-injection realness, and we're gonna read it together 🫶

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✨ NAME ✨

text_poke_copy — copy instructions into (an unused part of) RX memory 💅

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🌸 SYNOPSIS 🌸

void * text_poke_copy (void *addr , const void *opcode , size_t len );

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🎀 ARGUMENTS 🎀

• addr — address to modify
• opcode — source of the copy
• len — length to copy, could be more than 2x PAGE_SIZE

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🦋 DESCRIPTION 🦋

⚠️ Not safe against concurrent execution ⚠️ like, fr fr, do not ignore this part.

It's useful for JITs to dump new code blocks into unused regions of RX memory. You can use it in conjunction with synchronize_rcu_tasks to wait for existing execution to quiesce after having made sure no existing functions pointers are live. no cap, that's the whole vibe 🔥

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👑 SEE ALSO 👑

Kernel file ./arch/x86/kernel/alternative.c — and yes, the whole friend group is here:

• text_poke_early(9)
• text_poke(9)
• text_poke_kgdb(9)
• text_poke_set(9)
• smp_text_poke_batch_finish(9)
• smp_text_poke_batch_add(9)
• smp_text_poke_single(9)

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mwah 💋 source/version: ./arch/x86/kernel · date: October 2026 · text_poke_copy(9) signing off, periodt 💜