STRUCT POLYVAL_CTX(9)

💅 struct polyval_ctx(9) — the Kernel API Manual, bestie edition 🎀

okay so this is a page from the Linux Kernel API Manual, and today's main character is struct polyval_ctx — no cap, the literal context for computing a POLYVAL value. she's giving "I hold your state so you don't have to" energy ✨

---

🌸 NAME 🌸

struct polyval_ctx — Context for computing a POLYVAL value 💖

Like, she's the lil' workspace where the POLYVAL math happens. Obsessed.

---

✨ SYNOPSIS ✨

struct polyval_ctx {
    const struct polyval_key *key;
    struct polyval_elem acc;
    size_t partial;
 };

that's the whole struct, bestie — three members, zero drama 🦋

---

🫶 Members 🫶

so here's the breakdown of every field, and yes I'm doing all of them:

• key — a pointer to the prepared POLYVAL key. 🗝️ important! the user of the API is responsible for ensuring that the key lives as long as the context. that's on you, not on the kernel — if the key dips out early, that's a you problem, fr fr. 😭
• acc — the accumulator. 💜 she accumulates. that's her job. that's her whole vibe.
• partial — the number of data bytes processed so far, modulo POLYVAL_BLOCK_SIZE. so like, the leftover-bytes counter. the "how far into the current block are we" situation. 🌈

---

👀 SEE ALSO 👀

okay this list is long but every single one of these is iconic in her own right, no skips:

• Kernel file ./include/crypto/gf128hash.h — the ✨source✨
• struct polyval_elem(9)
• struct ghash_key(9)
• struct polyval_key(9)
• struct ghash_ctx(9)
• ghash_preparekey(9)
• polyval_preparekey(9)
• ghash_init(9)
• polyval_init(9)
• polyval_import_blkaligned(9)
• polyval_export_blkaligned(9)
• ghash_update(9)
• polyval_update(9)
• ghash_final(9)
• polyval_final(9)
• ghash(9)
• polyval(9)

the ghash girlies and the polyval girlies, side by side. 💅 we love a crossover episode.

---

🎀 lowkey reminder: key has to outlive the context. I said what I said. don't come crying to me when your pointer is dangling. 💀

---

and that's the page! this one came out of ./include/crypto, dated October 2026, and it's literally titled struct polyval_ctx(9) — so yeah, go forth and hash responsibly, bestie 🧚💖✨