get_desc(9)

💅 get_desc(9) — like, the segment descriptor grabber

ok so this is get_desc, and it lives in the kernel API manual (section 9 ofc, we love a manual page moment) — welcome to the group chat bestie 🫶

---

✨ NAME ✨

get_desc — literally just, obtain contents of a segment descriptor. that's the whole vibe. 🎀

---

✨ SYNOPSIS ✨

bool get_desc (struct desc_struct *out , unsigned short sel );

no cap, that's the signature. struct desc_struct *out and unsigned short sel, in that order, periodt. 💅

---

✨ ARGUMENTS ✨

• out — the segment descriptor contents, but only on success bestie. if it worked, this is where the goods land. ✨
• sel — the segment selector. yeah. the selector. the little number that points at the thing. 🎯

---

✨ DESCRIPTION ✨

okay so picture this 🌸 — you hand over a segment selector, and this function gets you a pointer to the segment descriptor it corresponds to. both the global and local descriptor tables are supported, so whichever table your selector is living in, get_desc has you covered. iykyk 💖

then the returns, and honestly the way these are laid out is iconic in a chaotic way:

• True on success, false on failure. yes. a bool. the synopsis literally says bool. we love consistency. 🤡
• NULL on error.

⚠️ heads up: that's exactly what the page says — True/false for success/failure, and NULL on error. i'm not gonna gaslight you into thinking there's more detail than there is. that's the whole description fr fr 💀

---

✨ SEE ALSO ✨

bestie the SEE ALSO section is long, like it is giving main character energy with how many friends it has 👑 and they all live in the kernel file ./arch/x86/lib/insn-eval.c — go drink from that firehose, i believe in you 🦋

• is_string_insn(9)
• insn_has_rep_prefix(9)
• get_seg_reg_override_idx(9)
• check_seg_overrides(9)
• resolve_default_seg(9)
• resolve_seg_reg(9)
• get_segment_selector(9)
• get_reg_offset_16(9)
• insn_get_seg_base(9)
• get_seg_limit(9)
• insn_get_code_seg_params(9)
• insn_get_modrm_rm_off(9)
• insn_get_modrm_reg_off(9)
• insn_get_modrm_reg_ptr(9)
• get_seg_base_limit(9)
• get_eff_addr_reg(9)
• get_eff_addr_modrm(9)
• get_eff_addr_modrm_16(9)
• get_eff_addr_sib(9)
• get_addr_ref_16(9)
• get_addr_ref_32(9)
• get_addr_ref_64(9)
• insn_get_addr_ref(9)
• insn_fetch_from_user(9)
• insn_fetch_from_user_inatomic(9)
• insn_decode_from_regs(9)
• insn_decode_mmio(9)

that's all 29 of them, counted twice, no skips, no crumbs left behind. ate. 🔥

---

🌈 the sign-off 🌈

okay that's the page!! this little icon comes from the source path ./arch/x86/lib, dated October 2026, and it's filed under get_desc(9) — so if you forget where you found it, that's your receipt bestie 🧚💜

mwah, go read a descriptor table, you're doing amazing 🍓⭐