skb_unshare(9)

📦 version 7.3.1, in nixpkgs unstable

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

okay so bestie, welcome to the <pink>Kernel API Manual</pink> ✨ and today's main character is skb_unshare, the function that says "no, you cannot share that, I'm making you your own copy" 🫶

🎀 NAME 🎀

skb_unshare — make a copy of a shared buffer

like, un-share it. de-clone it. give it its own vibe. you get it 💅

✨ SYNOPSIS ✨

struct sk_buff * skb_unshare (struct sk_buff *skb , gfp_t pri );

yes the spacing is exactly like that, don't come for me, I'm just the messenger 😭

🌸 ARGUMENTS 🌸

  • skb — buffer to check 👀 this is the one we're vibe-checking to see if it's a clone or not
  • pri — priority for memory allocation, aka the gfp flags you're passing in so kmalloc knows how much of a hurry you're in 🏃‍♀️

🦋 DESCRIPTION 🦋

so here's the tea ☕️ — if the socket buffer is a clone, this function creates a new copy of the data, drops a reference count on the old copy, and returns the new copy with the reference count at 1. slay! fresh buffer, fresh start, count reset, iconic behavior 👑

if the buffer is not a clone, the original buffer is just returned to you. no copy, no drama, we're just sending it right back 💖

bestie please read this part carefully 🙈 when called with a spinlock held or from interrupt state, pri must be GFP_ATOMIC. no cap. don't be out here sleeping in interrupt context, that's giving main character villain energy 💀

and if the memory allocation fails? NULL is returned. that's it. that's the whole thing. so like... check for it, okay? 😭

👑 SEE ALSO 👑

it's giving the whole friend group — the kernel file is ./include/linux/skbuff.h and honestly here's everyone:

iykyk 🔥 that's a lot of friends and honestly? obsessed with the community 🌈

that's the whole page bestie, go forth and un-share those buffers responsibly 🧚

sign-off time 🎀 this one lives in ./include/linux, dated October 2026, and it's filed under skb_unshare(9) — periodt 💜

📦 where this page comes from