TEE_IOC_SHM_ALLOC(9)

💖 TEE_IOC_SHM_ALLOC 💖

okay so bestie, we're in the TEE_IOC_SHM_ALLOC(9) page today — that's a section 9 Kernel API Manual situation, very kernel-core of us — and honestly? it's a short one. a little snack. let's get into it 🎀

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✨ NAME ✨

TEE_IOC_SHM_ALLOC — literally just allocate shared memory, that's the whole vibe 💅

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🌸 SYNOPSIS 🌸

TEE_IOC_SHM_ALLOC

no args, no drama. she's a bare ioctl and she knows it ✨

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🦋 DESCRIPTION 🦋

okay so what she does: she allocates shared memory between the user space process and the secure OS. that's the whole job. that's the assignment and she ate 🔥

she returns a file descriptor on success, or < 0 on failure. no cap, that's it 😭

so here's the part you actually need to remember, bestie: the returned file descriptor is used to map the shared memory into user space. and the shared memory is freed when the descriptor is closed and the memory is unmapped. notice the "and" — it's giving both-conditions-required energy, so don't think closing the fd alone is gonna clean everything up if the mapping's still hanging around 🫶

lowkey important: fd closed + memory unmapped, together, or the shared memory is not freed. it's not an either/or situation, iykyk 👑

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👑 SEE ALSO 👑

the whole friend group, in order, no one gets left out:

• Kernel file ./include/uapi/linux/tee.h struct tee_ioctl_version_data(9)
• TEE_IOC_VERSION(9)
• struct tee_ioctl_shm_alloc_data(9)
• struct tee_ioctl_buf_data(9)
• struct tee_ioctl_param(9)
• struct tee_ioctl_open_session_arg(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)

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and that's the whole page, babes 🌈 short, sweet, iconic. this one lives at ./include/uapi/linux and the version stamp is October 2026 — so like, mark your calendar bestie, mwah 💋💖