xa_err(9)

📦 version 7.3.1, in nixpkgs unstable

💅 xa_err(9) — the Kernel API Manual, but make it make sense

okay so bestie, welcome to xa_err, from the Kernel API Manual ✨ this is the lil function that turns an XArray result into an errno, and honestly? it's giving translator. it's giving "i speak pointer, you speak errno." let's get into it 🫶

✨ NAME ✨

xa_err — Turn an XArray result into an errno. that's it. that's the whole job. slay 💅

🌸 SYNOPSIS 🌸

int xa_err (void *entry );

yes bestie, that's the whole signature. one pointer in, one int out. iconic behavior honestly ✨

🎀 ARGUMENTS 🎀

  • entry — Result from calling an XArray function. literally just hand over whatever the XArray op gave you back and let xa_err do its thing 💖

🦋 DESCRIPTION 🦋

okay so here's the vibe: when an XArray operation can't complete an operation, it does not just give up — it returns a special pointer value which encodes an errno. sneaky? a little. genius? absolutely 🔥

This function extracts the errno from the pointer value, or returns 0 if the pointer does not represent an errno. so it's basically a vibe check for error pointers: errno in, errno out; not-an-errno in, 0 out. no cap 💀✨

💜 CONTEXT 💜

Any context. literally any. no restrictions, no "only in atomic," no "only at 3am on a tuesday." go off queen 👑

⭐ RETURN ⭐

A negative errno or 0. that's the whole menu, bestie — negative means "yeah something went wrong, here's the number," 0 means "no errno here, we're chilling" 🌈

real talk though: this returns 0, not a positive value, when there's no errno encoded. don't go treating 0 like "success code #0xDEADBEEF" or whatever. it's just zero 🙈

🔥 SEE ALSO 🔥

Kernel file ./include/linux/xarray.h — and like, a lot of friends. buckle up bestie, this is the whole group chat 💅:

like i said. whole group chat. mwah 💋

k bye bestie, go forth and decode those pointers 🧚💖

this lil page lives in ./include/linux, dated October 2026, and it's filed under xa_err(9) — see you in the man pages, diva 👑✨

📦 where this page comes from