vdso_update_begin(9)

💅 vdso_update_begin(9) 💅

okay so this is a page straight out of the Kernel API Manual bestie, and it's literally about starting a VDSO update section. yes we're in the kernel, yes we're being careful, no you cannot skip the vibes check 🎀

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✨ NAME ✨

vdso_update_begin — start of a VDSO update section. it's giving "beginning of something important" energy 🌸

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✨ SYNOPSIS ✨

unsigned long vdso_update_begin (void );

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✨ ARGUMENTS ✨

• void — no arguments. nothing. zero. empty set. she takes nothing and she gives you back a flag 💅

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✨ DESCRIPTION ✨

okay so here's the tea 🍵 — this lets architecture code safely update the architecture specific VDSO data. and "safely" is doing a LOT of work in that sentence, so let's break down exactly what she does:

• disables interrupts — yep, full focus mode, no interruptions, do not disturb 🚫
• acquires the timekeeper lock — this serializes her against concurrent updates coming from timekeeping, so nobody's out here editing the same thing at the same time 😤
• invalidates the VDSO data sequence counter — this is the big one, because it prevents concurrent readers from accessing inconsistent data. no half-updated reads, no messy in-between states, we simply do not allow it 👑

basically she locks everything down so the update can happen in peace. iconic behaviour, honestly 🫶

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✨ RETURN ✨

she returns the saved interrupt flags — and here's the important part, bestie: those flags need to be handed in to vdso_update_end. like, that's not optional. don't lose them, don't hold onto them, just pass them along 🙈

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🌈 SEE ALSO 🌈

• Kernel file ./kernel/time/vsyscall.c
• vdso_update_end(9) — the other half of this whole situation, go read it next fr fr 💖

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okay that's the whole page!! short and sweet and she ate ✨ this one's from <pink>./kernel/time</pink>, dated October 2026, in the Kernel API Manual — mwah, go forth and update your VDSO responsibly 🦋💜