bpf_wakeup_s...es_read_lock(9)

bpf_wakeup_s...es_read_lock(9)

okay bestie, this is the Kernel API Manual page for bpf_wakeup_s...es_read_lock(9) — yes, the name is a whole mouthful, but we're gonna get through it together 🫶✨

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🌸 NAME 🌸

bpf_wakeup_sources_read_lock — acquire the SRCU lock for wakeup sources. that's the whole vibe 💅

✨ SYNOPSIS ✨

__bpf_kfunc struct bpf_ws_lock * bpf_wakeup_sources_read_lock (void );

🎀 ARGUMENTS 🎀

• void — no arguments. not a single one. it's giving "I travel light" 💀

🦋 DESCRIPTION 🦋

so the underlying SRCU lock returns an integer index. but the BPF verifier is highkey strict: it requires a pointer (PTR_TO_BTF_ID) to strictly track the state of acquired resources using KF_ACQUIRE and KF_RELEASE semantics.

that's where the opaque structure pointer (struct bpf_ws_lock *) comes in — it satisfies the verifier while safely encoding the integer index within the pointer address itself. iconic little trick, no cap ✨

👑 RETURN 👑

an opaque pointer encoding the SRCU lock index + 1 (to avoid NULL). that + 1 is doing important work, bestie — no NULL energy allowed 💅

🔥 SEE ALSO 🔥

Kernel file ./drivers/base/power/wakeup.c:

• wakeup_source_create(9)
• wakeup_source_destroy(9)
• wakeup_source_add(9)
• wakeup_source_remove(9)
• wakeup_source_register(9)
• wakeup_source_unregister(9)
• wakeup_sources_read_lock(9)
• wakeup_sources_read_unlock(9)
• wakeup_sources_walk_start(9)
• wakeup_sources_walk_next(9)
• device_wakeup_attach(9)
• device_wakeup_enable(9)
• device_wakeup_attach_irq(9)
• device_wakeup_detach_irq(9)
• device_wakeup_arm_wake_irqs(9)
• device_wakeup_disarm_wake_irqs(9)
• device_wakeup_detach(9)
• device_wakeup_disable(9)
• device_set_wakeup_capable(9)
• device_set_wakeup_enable(9)
• wakeup_source_not_usable(9)
• wakeup_source_activate(9)
• wakeup_source_report_event(9)
• __pm_stay_awake(9)
• pm_stay_awake(9)
• wakeup_source_deactivate(9)
• __pm_relax(9)
• pm_relax(9)
• pm_wakeup_timer_fn(9)
• pm_wakeup_ws_event(9)
• pm_wakeup_dev_event(9)
• pm_wakeup_pending(9)
• pm_get_wakeup_count(9)
• pm_save_wakeup_count(9)
• pm_wakep_autosleep_enabled(9)
• print_wakeup_source_stats(9)
• wakeup_sources_stats_seq_show(9)
• bpf_wakeup_sources_read_unlock(9)
• bpf_wakeup_sources_get_head(9)

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signed off with source/version ./drivers/base/power and the date October 2026 — catch you in bpf_wakeup_s...es_read_lock(9) land, bestie 🫶💖