make_kgid(9)

🌸 NAME 🌸

make_kgid — maps a user-namespace gid pair into a kgid. This is make_kgid(9) from the Kernel API Manual, and we're gonna get into it, bestie 🫶✨

✨ SYNOPSIS ✨

kgid_t make_kgid (struct user_namespace *ns , gid_t gid );

🎀 ARGUMENTS 🎀

• ns — the user namespace that the gid is in. Like, which namespace's world are we translating from? 🌍
• gid — the group identifier. The gid in question, fr fr 👑

🦋 DESCRIPTION 🦋

Okay so make_kgid maps a user-namespace gid pair into a kernel-internal kgid, and then returns that kgid. That's the whole glow-up: user-namespace gid goes in, kernel-internal kgid comes out 💅✨

When there is no mapping defined for the user-namespace gid pair, INVALID_GID is returned. Not a vibe, but it's the documented behavior 😭. Callers are expected to test for and handle INVALID_GID being returned — like, please check, bestie, don't just ignore the return value 🙈. And INVALID_GID may be tested for using gid_valid. Iconic little validation check, no cap ✅

🌈 SEE ALSO 🌈

• Kernel file ./kernel/user_namespace.c
• make_kuid(9)
• from_kuid(9)
• from_kuid_munged(9)
• from_kgid(9)
• from_kgid_munged(9)
• make_kprojid(9)
• from_kprojid(9)
• from_kprojid_munged(9)
• verify_root_map(9)

That's the whole page, bestie 🫶 — brought to you by the ./kernel source/version, dated October 2026, and yes, it's still make_kgid(9) at the bottom 😌🎀