smack_mmap_file(9)

📦 version 7.3.1, in nixpkgs unstable

💅 smack_mmap_file(9) — like, the Kernel API Manual era 🎀

okay bestie, buckle up, we're deep in the security/smack girlies now 🦋 this one's a little function from the Kernel API Manual and she's lowkey iconic. not me reading a manpage for fun. anyway—

✨ NAME ✨

smack_mmap_file — check permissions for a mmap operation. fr fr that's the whole vibe check: does this mapping get the green light or not 💅

🌸 SYNOPSIS 🌸

int smack_mmap_file (struct file *file , unsigned long reqprot ,
       unsigned long prot , unsigned long flags );

like, yeah, that's the signature. copy it exactly, don't be out here inventing parameters 🙈

🎀 ARGUMENTS 🎀

  • file — contains the file structure for file to map (and yes she may be NULL, more on that in a sec). 👑
  • reqprot — contains the protection requested by the application. like what the app wants.
  • prot — contains the protection that will be applied by the kernel. what's actually happening, iykyk.
  • flags — contains the operational flags. the little extras. ⭐

💖 DESCRIPTION 💖

so the tea is: the file may be NULL, e.g. if mapping anonymous memory. meaning sometimes there's literally no file behind it and that's fine, that's the whole point 🫶

Return 0 if permission is granted. that's it. zero means slay, you're in. 💀✨

🦋 SEE ALSO 🦋

Kernel file ./security/smack/smack_lsm.c — and okay she has a lot of friends, so here's the full squad, no cap, everyone gets named:

like, that's the whole group chat. everyone showed up. 💜

bestie reminder: file may legit be NULL (anonymous memory, remember?) so don't go dereferencing it without checking. that's the only real trap here. 🍓

and that's the page!! 🌈 she lives in ./security/smack, dated October 2026 — main character energy, periodt. go read the other smack pages, ily, bye 💖✨🧚

📦 where this page comes from