pmcraid_check_ioctl_buffer(9)

📦 version 7.3.1, in nixpkgs unstable

💅 pmcraid_check_ioctl_buffer — the vibe check for user buffers

okay so this is a page from the Kernel API Manual, and it's all about pmcraid_check_ioctl_buffer(9) — yes bestie, that whole mouthful is the function name. It's the little bouncer at the door that checks whether we're even allowed to touch the user's buffer. 🫶

✨ SYNOPSIS ✨

int pmcraid_check_ioctl_buffer (int cmd , void __user *arg , struct
       pmcraid_ioctl_header *hdr );

like, that's the whole signature, copied exactly, no cap 🎀

🌸 ARGUMENTS 🌸

  • cmd — the ioctl command. the actual instruction, the "what are we even doing here" of it all 💫
  • arg — the user buffer. yep, the buffer that lives in userland 👀
  • hdr — pointer to kernel memory for struct pmcraid_ioctl_header. this is where the header's gonna land 🌈

💖 DESCRIPTION 💖

Return value: a negative error code if there are access issues 😭 — like, if something went wrong with permissions/access, you get a negative number back, that's the heads-up.

Otherwise? zero. iconic. zero means we're good ✨

Upon success, it returns the ioctl header copied out of the user buffer — so hdr gets filled with the header that came from the user's buffer. literally the main character of this whole function 💅

lowkey the whole point: access check first, then the header copy falls out on success. no cap, that's it.

🦋 SEE ALSO 🦋

fr fr bestie, the related-stuff list here is long, so buckle up — every single one, exactly as written, in order 👑

Kernel file ./drivers/scsi/pmcraid.c

and that's the whole page, bestie 💜 this one shipped out of ./drivers/scsi in October 2026 — Kernel API Manual energy only, mwah 🧚✨

📦 where this page comes from