aa_simple_write_to_buffer(9)

💅 aa_simple_write_to_buffer

okay so bestie, welcome to the aa_simple_write_to_buffer(9) page from the Kernel API Manual — it’s literally the common routine for getting policy from user, and it’s giving “copy the user’s bytes into a kernel buffer” main character energy. let’s get into it 🫶✨

💖 NAME 💖

aa_simple_write_to_buffer — common routine for getting policy from user. no cap, that’s the whole vibe: a shared helper for getting policy from user. 👑

✨ SYNOPSIS ✨

struct aa_loaddata * aa_simple_write_to_buffer (const char __user
*userbuf , size_t alloc_size , size_t copy_size , loff_t *pos );

🌸 ARGUMENTS 🌸

• userbuf — user buffer to copy data from. It is NOT NULL; do not play with that. 🙈
• alloc_size — size of user buffer. Hard requirement: REQUIRES: alloc_size >= copy_size — bestie, respect the math. 🧮💅
• copy_size — size of data to copy from user buffer.
• pos — position write is at in the file. It is NOT NULL too. 📍

🔥 RETURN 🔥

On success you get a kernel buffer containing copy of user buffer data. On failure you get an ERR_PTR. That’s it, that’s the tea. 💀✨

👀 SEE ALSO 👀

• Kernel file ./security/apparmor/apparmorfs.c and the whole friend group: mangle_name(9), __aafs_setup_d_inode(9), aafs_create(9), aafs_create_file(9), aafs_create_dir(9), aafs_remove(9), aa_get_data_from_compressed(9), query_data(9), query_label(9), aa_write_access(9), __next_ns(9), __first_profile(9), __next_profile(9), next_profile(9), p_start(9), p_next(9), p_stop(9), seq_show_profile(9), entry_create_file(9), entry_create_dir(9), entry_remove_file(9), entry_remove_dir(9), aa_destroy_aafs(9), aa_create_aafs(9).

source/version: ./security/apparmor · date: October 2026 · page: aa_simple_write_to_buffer(9). stay hydrated, keep your buffers valid, and slay the kernel, bestie 💖🎀🦋