dvb_ringbuffer_write_user(9)

📦 version 7.3.1, in nixpkgs unstable

💫 dvb_ringbuffer_write_user — the "write stuff from userspace" one (kernel API manual, bestie) 💫

Okay so first of all, hi, welcome to the dvb_ringbuffer_write_user(9) page — this is the kernel API manual version, and we are literally about to make ring buffers make sense. 🫶

🌸 NAME 🌸

dvb_ringbuffer_write_user — writes a buffer that came in via a user pointer, no cap 💅

✨ SYNOPSIS ✨

ssize_t dvb_ringbuffer_write_user (struct dvb_ringbuffer *rbuf , const
       u8 __user *buf , size_t len );

Look at her. Iconic signature. We'll walk through it, don't worry. 🎀

🦋 ARGUMENTS 🦋

  • rbuf — pointer to struct dvb_ringbuffer, the ring buffer main character herself 👑
  • buf — pointer to the buffer where the data will be read from
  • len — bytes from ring buffer into buf

💖 DESCRIPTION 💖

This variant is the userspace one, okay? The way it works is it assumes that the buffer is memory up in userspace. So, internally, it's gonna call copy_from_user. That's the whole vibe — user memory in, ring buffer gets fed, slay. 🔥

🌈 RETURN 🌈

It gives you the number of bytes transferred — or -EFAULT if the copy flopped 😭. That's it, that's the return value.

🎀 SEE ALSO 🎀

The whole friend group, fr fr — all of these live in the kernel file ./include/media/dvb_ringbuffer.h:

Quick vibe check bestie: this one is specifically for when your data is chillin' in userspace memory — that's why it does the copy_from_user thing internally. Don't come at it with a kernel pointer and expect the same energy. 💀

Okay that's the whole page, you ate that. 💅 This lil' cutie is from the ./include/media corner of the tree, and the page is dated October 2026. Byeee, go write some ring buffers 🦋✨

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