NE_ERR_MEM_R...ALREADY_USED(9)

💅 NE_ERR_MEM_REGION_ALREADY_USED 💅

okay bestie, welcome to the NE_ERR_MEM_REGION_ALREADY_USED(9) page — yes that's the whole title, we're in the Kernel API Manual and we're getting specific today. This is one of those Nitro Enclaves (NE) Kernel Driver Interface error codes, and honestly? It's giving "you already did that, babe." 🎀

✨ NAME ✨

NE_ERR_MEM_REGION_ALREADY_USED — the user space memory region is already used. That's it, that's the whole vibe. You tried to hand over a chunk of user space memory and the kernel was like "girl, I've seen this one before." 🙈

🌸 SYNOPSIS 🌸

NE_ERR_MEM_REGION_ALREADY_USED

literally just the constant itself, no arguments, no flags, no drama. She's a standalone icon. ✨

🦋 SEE ALSO 🦋

okay this is the part where the page goes full group-chat-tagging-everyone, so buckle up bestie, because the whole NE squad is here 💖

• Kernel file ./include/uapi/linux/nitro_enclaves.h — the header where all of this lives, go look, iykyk
• Nitro Enclaves (NE) Kernel Driver Interface(9) — the mothership page, start here fr fr
• NE_CREATE_VM(9)
• NE_ADD_VCPU(9)
• NE_GET_IMAGE_LOAD_INFO(9)
• NE_SET_USER_MEMORY_REGION(9) — the one most likely to hand you this error, just saying 👀
• NE_START_ENCLAVE(9)
• NE specific error codes(9) — the whole error-code fam, all of 'em
• NE_ERR_VCPU_ALREADY_USED(9)
• NE_ERR_VCPU_NOT_IN_CPU_POOL(9)
• NE_ERR_VCPU_INVALID_CPU_CORE(9)
• NE_ERR_INVALID_MEM_REGION_SIZE(9)
• NE_ERR_INVALID_MEM_REGION_ADDR(9)
• NE_ERR_UNALIGNED_MEM_REGION_ADDR(9)
• NE_ERR_MEM_NOT_HUGE_PAGE(9)
• NE_ERR_MEM_DIFFERENT_NUMA_NODE(9)
• NE_ERR_MEM_MAX_REGIONS(9)
• NE_ERR_NO_MEM_REGIONS_ADDED(9)
• NE_ERR_NO_VCPUS_ADDED(9)
• NE_ERR_ENCLAVE_MEM_MIN_SIZE(9)
• NE_ERR_FULL_CORES_NOT_USED(9)
• NE_ERR_NOT_IN_INIT_STATE(9)
• NE_ERR_INVALID_VCPU(9)
• NE_ERR_NO_CPUS_AVAIL_IN_POOL(9)
• NE_ERR_INVALID_PAGE_SIZE(9)
• NE_ERR_INVALID_FLAG_VALUE(9)
• NE_ERR_INVALID_ENCLAVE_CID(9)
• Image load info flags(9)
• NE_EIF_IMAGE(9)
• struct ne_image_load_info(9)
• User memory region flags(9)
• NE_DEFAULT_MEMORY_REGION(9)
• struct ne_user_memory_region(9) — the struct that started all this 💀
• Enclave start info flags(9)
• NE_ENCLAVE_PRODUCTION_MODE(9)
• NE_ENCLAVE_DEBUG_MODE(9)
• struct ne_enclave_start_info(9)

no cap: if you're staring down this error, the memory region you're passing along has already been claimed. Check the region before you re-add it — the answer is in NE_SET_USER_MEMORY_REGION(9), bestie. 🫶

and that's the page!! short, sweet, absolutely iconic of her. source is ./include/uapi/linux, dated October 2026, and she's filed under NE_ERR_MEM_R...ALREADY_USED(9) in case you need to find her again. mwah 💋✨🌈