security_mmap_file(9)

📦 version 7.3.1, in nixpkgs unstable

💅 security_mmap_file(9) 💅

okay bestie, so this is a page from the Kernel API Manual — yes, section 9, the big-kid kernel-functions section — and today's main character is security_mmap_file. she's short, she's sweet, and she's literally the bouncer for mmap. let's get into it 🎀

✨ NAME ✨

security_mmap_file — check if mmap'ing a file is allowed 💖

🦋 SYNOPSIS 🦋

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

🌸 ARGUMENTS 🌸

  • file — the file. that's it, that's the whole description. it's giving minimal effort but honestly? iconic 💅 (and ngl, keep reading, because in the DESCRIPTION it turns out file is allowed to be NULL)
  • prot — the protection applied by the kernel 🛡️
  • flags — flags. just... flags. 🚩 the manpage said what it said.

🌈 DESCRIPTION 🌈

so what she actually does: she checks permissions for a mmap operation. permissions checked, vibe secured, no cap. ✨

and here's the important lil detail bestie: the file may be NULL — like, for example, if you're mapping anonymous memory 🫶. so don't come for her when file is NULL, that's literally a documented situation, not a bug. 🙈

⭐ RETURN ⭐

returns 0 if permission is granted. that's the whole return story — zero means yes. slay. 👑

👑 SEE ALSO 👑

alright bestie, buckle up, because this list is long — like, "she ate and then kept eating" long 💀. every single one, in order, no skipping, because we respect the lore:

like I said. she ate. all of it. 🍓

okay that's the whole page, bestie, you're officially caught up 💜 this lil drop comes to you at ./security in October 2026, and the page itself is security_mmap_file(9) — that's the name you'll be typing into <kbd>man</kbd> if you ever need her again. mwah! 😭🫶✨

📦 where this page comes from