STRUCT TEE_IOCTL_OPEN_SESSION_ARG(9)

🎀 struct tee_ioctl_open_session_arg — like, the NAME section, bestie 🎀

okay so this is struct tee_ioctl_open_session_arg from section 9 of the Kernel API Manual, and it is literally the "Open session argument" — that's the whole vibe. it's the little package of info you hand over when you wanna open a session with a Trusted Application. slay. 💅

✨ SYNOPSIS ✨

like, the shape of it, exactly:

struct tee_ioctl_open_session_arg {
    __u8 uuid[TEE_IOCTL_UUID_LEN];
    __u8 clnt_uuid[TEE_IOCTL_UUID_LEN];
    __u32 clnt_login;
    __u32 cancel_id;
    __u32 session;
    __u32 ret;
    __u32 ret_origin;
    __u32 num_params;
    struct tee_ioctl_param params[];
 };

꒰ঌ look at those params[] at the end, no cap, a flexible array member just vibing ໒꒱

🦋 Members 🦋

okay so every single field, with its direction tag, because the [in]/[out] thing matters SO much 🫶

• uuid — [in] the UUID of the Trusted Application. the who-you're-calling. 👑
• clnt_uuid — [in] the UUID of the client. that's you, bestie. 🫵
• clnt_login — [in] the login class of the client, and it's one of the TEE_IOCTL_LOGIN_* values listed above. iykyk 🌈
• cancel_id — [in] the cancellation id, a unique value that identifies this specific request. write it down, you'll want it later. 🎀
• session — [out] the session id. this is what you get back, the receipt. 🧾
• ret — [out] the return value. the verdict. 💀
• ret_origin — [out] the origin of the return value. like, where the verdict came from. 🔍
• num_params — [in] the number of struct tee_ioctl_param entries in params. count 'em, don't guess. 🔢
• params — the array of ioctl parameters. this one's just… the array. no direction tag, it's built different. 🦋

⚠️ reminder that num_params and params have to agree with each other, okay? that's the whole reason the count is a separate [in] field. don't set them to conflicting things, it's giving chaos. 😭

👀 SEE ALSO 👀

go read these next, i'm obsessed with this little family:

• Kernel file ./include/uapi/linux/tee.h
• struct tee_ioctl_version_data(9)
• TEE_IOC_VERSION(9)
• struct tee_ioctl_shm_alloc_data(9)
• TEE_IOC_SHM_ALLOC(9)
• struct tee_ioctl_buf_data(9)
• struct tee_ioctl_param(9)
• TEE_IOC_OPEN_SESSION(9)
• struct tee_ioctl_invoke_arg(9)
• TEE_IOC_INVOKE(9)
• struct tee_ioctl_cancel_arg(9)
• TEE_IOC_CANCEL(9)
• struct tee_ioctl_close_session_arg(9)
• TEE_IOC_CLOSE_SESSION(9)
• struct tee_iocl_supp_recv_arg(9)
• TEE_IOC_SUPPL_RECV(9)
• struct tee_iocl_supp_send_arg(9)
• TEE_IOC_SUPPL_SEND(9)
• struct tee_ioctl_shm_register_data(9)
• struct tee_ioctl_shm_register_fd_data(9)
• TEE_IOC_SHM_REGISTER_FD(9)
• TEE_IOC_SHM_REGISTER(9)
• struct tee_ioctl_object_invoke_arg(9)

okay that's the whole page, mwah 💖 this one lives down in ./include/uapi/linux, dated October 2026, and the page itself is tagged struct tee_..._session_arg(9) — go forth and open those sessions, bestie, you got this 🎀✨🦋