STRUCT TEE_SHM(9)

💖 struct tee_shm — the shared memory glow-up 💖

okay so this is a page from the Kernel API Manual (section 9, kernel land, very demure very mindful) and it's literally all about struct tee_shm — the shared memory object. it's giving "the thing that holds your bytes when the normal world and the secure world need to pass notes in class" ✨

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🌸 NAME 🌸

struct tee_shm — shared memory object. that's it. that's the whole name. iconic behavior honestly 🎀

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🦋 SYNOPSIS 🦋

here's the whole struct, bestie, copied exactly, do not touch:

struct tee_shm {
    struct tee_context *ctx;
    phys_addr_t paddr;
    void *kaddr;
    size_t size;
    unsigned int offset;
    struct page **pages;
    size_t num_pages;
    refcount_t refcount;
    u32 flags;
    int id;
    u64 sec_world_id;
 };

look at her. eleven fields, all main character energy 👑

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✨ Members ✨

okay so now we go member by member, no skipping, i don't make the rules (i do, actually, and the rule is keep every detail):

• ctx — the context using the object. like, whose vibe is this shm attached to 🫶
• paddr — physical address of the shared memory. the real-real address, ngl 📍
• kaddr — virtual address of the shared memory. the kernel's own little view of it 💜
• size — size of shared memory. how much room we're working with, periodt 📏
• offset — offset of buffer in user space. where the good stuff actually starts 🙈
• pages — locked pages from userspace. they're pinned down and they're staying put 🔒
• num_pages — number of locked pages. gotta count 'em 🧮
• refcount — reference counter. classic. keeps track of how many people are holding on 🌈
• flags — defined by TEE_SHM_* in tee_core.h. go look at the header, i'm not doing your homework for you 💅
• id — unique id of a shared memory object on this device, shared with user space. yes, user space gets to see this one, it's a whole collab 🤝
• sec_world_id — secure world assigned id of this shared memory object, not used by all drivers. lowkey not every driver bothers with it, so don't assume 🔥

fr fr: sec_world_id is not used by all drivers — so don't go reading it and acting surprised if it's not what you expected. that's on you bestie 😭

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👀 SEE ALSO 👀

the whole friend group, all linked in Kernel file ./include/linux/tee_drv.h:

• struct tee_context(9)
• tee_shm_alloc_kernel_buf(9)
• tee_shm_register_kernel_buf(9)
• tee_shm_register_fd(9)
• tee_shm_free(9)
• tee_shm_get_va(9)
• tee_shm_get_pa(9)
• tee_shm_get_size(9)
• tee_shm_get_pages(9)
• tee_shm_get_page_offset(9)
• tee_client_open_context(9)
• tee_client_close_context(9)
• tee_client_get_version(9)
• tee_client_open_session(9)
• tee_client_close_session(9)
• tee_client_system_session(9)
• tee_client_invoke_func(9)
• tee_client_cancel_req(9)
• struct tee_client_device(9)
• struct tee_client_driver(9)

like, that's the whole squad, go read them all, i'll wait 🍓

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and that's the page!! shipped from the source at ./include/linux, dated October 2026 — so yes she's from the future and she's still slaying 💅 k bye, go write some TEE code, i believe in you 🧚💖