sgx_ioc_encl...modify_types(9)

💅 sgx_ioc_encl...modify_types(9) — like, the glow-up edition ✨

okay bestie, so this is a page from the Kernel API Manual (section 9, kernel-space gang 🫶), and the name of the whole thing is sgx_ioc_enclave_modify_types — yes, the header is squished to sgx_ioc_encl...modify_types(9) because even man pages have a character limit, tragic, we move on 💀

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🎀 NAME 🎀

sgx_ioc_enclave_modify_types — the handler for %SGX_IOC_ENCLAVE_MODIFY_TYPES. that's it, that's the tweet ✨

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🌸 SYNOPSIS 🌸

long sgx_ioc_enclave_modify_types (struct sgx_encl *encl , void __user
*arg );

literally the whole signature, don't come for me about the line wrap 🙈

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🦋 ARGUMENTS 🦋

• encl — an enclave pointer 👑 (this is the main character)
• arg — a userspace pointer to a struct sgx_enclave_modify_types instance 💖

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✨ DESCRIPTION ✨

the ability to change the enclave page type supports the following use cases, and honestly? iconic behaviour:

• it is possible to add TCS pages to an enclave by changing the type of regular pages (SGX_PAGE_TYPE_REG) to TCS (SGX_PAGE_TYPE_TCS) pages. with this support the number of threads supported by an initialized enclave can be increased dynamically 🔥 like, glow-up your thread count while it's already running, no reboot era
• regular or TCS pages can dynamically be removed from an initialized enclave by changing the page type to SGX_PAGE_TYPE_TRIM. changing the page type to SGX_PAGE_TYPE_TRIM marks the page for removal, with actual removal done by the handler of SGX_IOC_ENCLAVE_REMOVE_PAGES ioctl, called after ENCLU[EACCEPT] is run on the SGX_PAGE_TYPE_TRIM page from within the enclave 👀 so like — trim is the notice, remove is the actual eviction, and ENCLU[EACCEPT] has to happen in between, iykyk

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💀 RETURN 💀

• 0 — success 🎉 slay
• -errno — otherwise 😭 that's the vibe check failing

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🌈 SEE ALSO 🌈

kernel file ./arch/x86/kernel/cpu/sgx/ioctl.c, plus the whole friend group:

• sgx_ioc_enclave_create(9)
• sgx_ioc_enclave_add_pages(9)
• sgx_ioc_enclave_init(9)
• sgx_ioc_enclave_provision(9)
• sgx_enclave_restrict_permissions(9)
• sgx_ioc_enclave_restrict_permissions(9)
• sgx_enclave_modify_types(9)
• sgx_encl_remove_pages(9)
• sgx_ioc_enclave_remove_pages(9)

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and that's the whole page, no crumbs left 💅 this lil masterpiece lives in ./arch/x86/kernel/cpu/sgx, dated October 2026, and it's brought to you by the same sgx_ioc_encl...modify_types(9) energy as the top of the page — full circle, periodt 🧚💜