bpf_prog_array_update_at(9)

💅 bpf_prog_array_update_at — the glow-up for your prog array

Okay bestie, so this is the bpf_prog_array_update_at(9) moment. It lives in the Kernel API Manual and it's literally here to update one program at a specific index inside a program array. Slay. ✨

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🌸 NAME 🌸

bpf_prog_array_update_at — updates the program at the given index into the program array. No cap, that's the whole assignment.

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🦋 SYNOPSIS 🦋

int bpf_prog_array_update_at (struct bpf_prog_array *array , int index ,
struct bpf_prog *prog );

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🎀 ARGUMENTS 🎀

• array — a bpf_prog_array. Yes, the actual array we're messing with. Main character energy.
• index — the index of the program to update. Like, which slot gets the new vibe.
• prog — the program to insert into the array. This is the new kid walking in. 💖

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🧚 DESCRIPTION 🧚

So here's the tea: it skips over dummy programs, by not counting them, when it's calculating the position of the program to update. That's the whole behavior. It's giving precision. It's giving "I know exactly which slot you mean." 🫶

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🔥 RETURN 🔥

• 0 — Success. We love a win. 💅
• -EINVAL — Invalid index value. It must be a non-negative integer, bestie. Negative index? Not today.
• -ENOENT — Index out of range. You aimed outside the array. Oops. 😭

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👑 SEE ALSO 👑

• Kernel file ./kernel/bpf/core.c
• ___bpf_prog_run(9)
• bpf_prog_select_runtime(9)
• bpf_prog_array_delete_safe_at(9)

Go read those if you want the full lore. Iykyk. 🌈

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Reminder: this is from ./kernel/bpf, dated October 2026, and the manual is literally named bpf_prog_array_update_at(9). Periodt. 🎀✨💜