kmsg_dump_get_buffer(9)

📦 version 7.3.1, in nixpkgs unstable

💖 kmsg_dump_get_buffer(9) — like, the kernel API manual bestie 💖

okay so real talk, we're in the Kernel API Manual and this function is kmsg_dump_get_buffer and it's gonna scoop up kmsg log lines for you. no cap, it's giving "archive girlie". let's go 🫶

✨ NAME ✨

kmsg_dump_get_buffer — copies kmsg log lines 📋

🌸 SYNOPSIS 🌸

bool kmsg_dump_get_buffer (struct kmsg_dump_iter *iter , bool syslog ,
       char *buf , size_t size , size_t *len_out );

like yes that's the whole signature, don't panic, we'll walk through every single arg 💅

🎀 ARGUMENTS 🎀

  • iter — the kmsg dump iterator 🌀 (your lil cursor bestie)
  • syslog — when true, the "<4>" prefixes are included ✨
  • buf — the buffer you're copying the line into 🧺
  • size — the maximum size of that buffer 📏
  • len_out — the length of the line that actually got placed into the buffer 📝

🦋 DESCRIPTION 🦋

So here's the vibe: it starts at the end of the kmsg buffer and fills the buffer you handed it with as many of the youngest kmsg records as actually fit in there. 🍼✨ If your buffer is big enough, all the available kmsg records get copied in one single call — one and done, iconic 👑

Consecutive calls will fill the buffer with the next block of available older records — and nope, it does not include the ones it already retrieved earlier. so it keeps walking backwards, no repeats 🙈

💀 Heads up: a return value of FALSE means there are, like, no more records to read. that's it, that's the whole message, the archive is empty, go home 😭

👑 SEE ALSO 👑

Kernel file ./kernel/printk/printk.c

like that's a whole friend group of printk besties, go say hi to all of them fr fr 🫶

okay that's the page!! this one came from ./kernel/printk and it's dated October 2026, and the page itself is kmsg_dump_get_buffer(9) — k byeee, go dump some buffers responsibly 💅🎀💖

📦 where this page comes from