read_pkcs7(9)

💖 read_pkcs7(9) 💖

okay so bestie, this is a page from the Kernel API Manual — read_pkcs7(9), and it's literally the read handler for that one securityfs path. let's get into it 🫶

---

✨ NAME ✨

read_pkcs7 — the read handler for "ipe/policies/$name/pkcs7". that's it, that's the whole vibe. 🎀

---

🌸 SYNOPSIS 🌸

ssize_t read_pkcs7 (struct file *f , char __user *data , size_t len ,
loff_t *offset );

---

🦋 ARGUMENTS 🦋

• f — supplies a file structure that represents the securityfs node. it's giving "here's the node, do your thing". 💅
• data — supplies a buffer that got passed to the write syscall.
• len — supplies the length of data. gotta know how much you're working with, obviously.
• offset — unused. not me ignoring it entirely 🙈

---

💜 DESCRIPTION 💜

on success, data gets populated with the pkcs7 blob that represents the policy. slay. ⭐

but lowkey — if the policy is unsigned (like the boot policy, bestie), this returns -ENOENT. no signature, no blob. 😭

---

🔥 RETURN 🔥

• Length of buffer written — success 👑
• -ENOENT — policy is initializing/deleted, or it's unsigned 💀

---

🌈 SEE ALSO 🌈

kernel file ./security/ipe/policy_fs.c and friends:

• struct ipefs_file(9)
• read_policy(9)
• read_name(9)
• read_version(9)
• setactive(9)
• getactive(9)
• update_policy(9)
• delete_policy(9)
• ipe_del_policyfs_node(9)
• ipe_new_policyfs_node(9)

---

and that's the whole page, bestie 💖 this one lives over in ./security/ipe, from the October 2026 drop — iykyk. go read some pkcs7, no cap. 🧚✨