build_id_parse_nofault(9)

📦 version 7.3.1, in nixpkgs unstable

✨ build_id_parse_nofault 💅

okay so this is a page from the Kernel API Manual, and it's literally about parsing the build ID of an ELF file that's mapped to a vma. yes bestie, we're in kernel land now 🧚

🌸 SYNOPSIS 🌸

int build_id_parse_nofault (struct vm_area_struct *vma , unsigned char
       *build_id , __u32 *size );

like, that's the whole signature, no cap. three args, one int coming back at you 💖

🎀 ARGUMENTS 🎀

  • vma — the vma object itself. the main character of this whole situation 👑
  • build_id — your buffer where the build id goes. heads up: it needs to be at least BUILD_ID_SIZE long, so don't skimp on the buffer, bestie 😭
  • size — this one returns the actual build id size in case of success. it's giving output parameter energy ✨

🦋 DESCRIPTION 🦋

so here's the vibe check: this function assumes no page fault can be taken. like, zero. none. nope 🙈

which means — if the relevant portions of the ELF file aren't already paged in, then fetching the build ID just... fails. that's it. that's the deal. it's a no-fault zone, iykyk 💀

🔥 RETURN 🔥

  • 0 on success — slay 💅
  • negative error, otherwise — not slay 😭

🌈 SEE ALSO 🌈

all the kernel file besties over at ./lib/buildid.c:

okay that's the whole page, periodt 🫶 this one's brought to you by ./lib, dated October 2026 — and yes, the manual name again since we're being thorough: Kernel API Manual, build_id_parse_nofault(9). take care of your buffers and stay fault-free, bestie 💜🎀

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