wakeup sources kfunc: CI test#12038
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wusamuel6 wants to merge 2 commits intokernel-patches:bpf-next_basefrom
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wakeup sources kfunc: CI test#12038wusamuel6 wants to merge 2 commits intokernel-patches:bpf-next_basefrom
wusamuel6 wants to merge 2 commits intokernel-patches:bpf-next_basefrom
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Iterating through wakeup sources via sysfs or debugfs can be inefficient or restricted. Introduce BPF kfuncs to allow high-performance and safe in-kernel traversal of the wakeup_sources list. There is at least a 30x speedup for walking 150 wakeup sources and all their attributes. The new kfuncs include: - bpf_wakeup_sources_get_head() to obtain the list head. - bpf_wakeup_sources_read_lock/unlock() to manage the SRCU lock. For verifier safety, the underlying SRCU index is wrapped in an opaque 'struct bpf_ws_lock' pointer. This enables the use of KF_ACQUIRE and KF_RELEASE flags, allowing the BPF verifier to strictly enforce paired lock/unlock cycles and prevent resource leaks. Signed-off-by: Samuel Wu <wusamuel@google.com>
Introduce a set of BPF selftests to verify the safety and functionality of wakeup_source kfuncs. The suite includes: 1. A functional test (test_wakeup_source.c) that iterates over the global wakeup_sources list. It uses CO-RE to read timing statistics and validates them in user-space via the BPF ring buffer. 2. A negative test suite (wakeup_source_fail.c) ensuring the BPF verifier correctly enforces reference tracking and type safety. 3. Enable CONFIG_PM_WAKELOCKS in the test config, allowing creation of wakeup sources via /sys/power/wake_lock. A shared header (wakeup_source.h) is introduced to ensure consistent memory layout for the Ring Buffer data between BPF and user-space. Signed-off-by: Samuel Wu <wusamuel@google.com>
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wakeup sources kfunc: CI test, mostly for s390