bpf: Add wakeup_source iterators

kernel/bpf/Makefile

@@ -56,6 +56,7 @@ obj-$(CONFIG_BPF_SYSCALL) += kmem_cache_iter.o
 ifeq ($(CONFIG_DMA_SHARED_BUFFER),y)
 obj-$(CONFIG_BPF_SYSCALL) += dmabuf_iter.o
 endif
+obj-$(CONFIG_BPF_SYSCALL) += wakeup_source_iter.o
 
 CFLAGS_REMOVE_percpu_freelist.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_bpf_lru_list.o = $(CC_FLAGS_FTRACE)

kernel/bpf/helpers.c

@@ -4518,6 +4518,9 @@ BTF_ID_FLAGS(func, bpf_iter_dmabuf_new, KF_ITER_NEW | KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_iter_dmabuf_next, KF_ITER_NEXT | KF_RET_NULL | KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_iter_dmabuf_destroy, KF_ITER_DESTROY | KF_SLEEPABLE)
 #endif
+BTF_ID_FLAGS(func, bpf_iter_wakeup_source_new, KF_ITER_NEW | KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_iter_wakeup_source_next, KF_ITER_NEXT | KF_RET_NULL | KF_SLEEPABLE)
+BTF_ID_FLAGS(func, bpf_iter_wakeup_source_destroy, KF_ITER_DESTROY | KF_SLEEPABLE)
 BTF_ID_FLAGS(func, __bpf_trap)
 BTF_ID_FLAGS(func, bpf_strcmp);
 BTF_ID_FLAGS(func, bpf_strcasecmp);

kernel/bpf/wakeup_source_iter.c

@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2025 Google LLC */
+#include <linux/bpf.h>
+#include <linux/btf_ids.h>
+#include <linux/kernel.h>
+#include <linux/pm_wakeup.h>
+#include <linux/seq_file.h>
+
+struct bpf_iter__wakeup_source {
+	__bpf_md_ptr(struct bpf_iter_meta *, meta);
+	__bpf_md_ptr(struct wakeup_source *, wakeup_source);
+};
+
+static void *wakeup_source_iter_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	int *srcuidx = seq->private;
+	struct wakeup_source *ws;
+	loff_t i;
+
+	*srcuidx = wakeup_sources_read_lock();
+
+	ws = wakeup_sources_walk_start();
+	for (i = 0; ws && i < *pos; i++)
+		ws = wakeup_sources_walk_next(ws);
+
+	return ws;
+}
+
+static void *wakeup_source_iter_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct wakeup_source *ws = v;
+
+	++*pos;
+
+	return wakeup_sources_walk_next(ws);
+}
+
+static void wakeup_source_iter_seq_stop(struct seq_file *seq, void *v)
+{
+	int *srcuidx = seq->private;
+
+	if (*srcuidx >= 0)
+		wakeup_sources_read_unlock(*srcuidx);
+	*srcuidx = -1;
+}
+
+static int __wakeup_source_seq_show(struct seq_file *seq, void *v, bool in_stop)
+{
+	struct bpf_iter_meta meta = {
+		.seq = seq,
+	};
+	struct bpf_iter__wakeup_source ctx = {
+		.meta = &meta,
+		.wakeup_source = v,
+	};
+	struct bpf_prog *prog = bpf_iter_get_info(&meta, in_stop);
+
+	if (prog)
+		return bpf_iter_run_prog(prog, &ctx);
+
+	return 0;
+}
+
+static int wakeup_source_iter_seq_show(struct seq_file *seq, void *v)
+{
+	return __wakeup_source_seq_show(seq, v, false);
+}
+
+static const struct seq_operations wakeup_source_iter_seq_ops = {
+	.start	= wakeup_source_iter_seq_start,
+	.next	= wakeup_source_iter_seq_next,
+	.stop	= wakeup_source_iter_seq_stop,
+	.show	= wakeup_source_iter_seq_show,
+};
+
+static const struct bpf_iter_seq_info wakeup_source_iter_seq_info = {
+	.seq_ops		= &wakeup_source_iter_seq_ops,
+	.seq_priv_size		= sizeof(int),
+};
+
+static struct bpf_iter_reg bpf_wakeup_source_reg_info = {
+	.target			= "wakeup_source",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{
+			offsetof(struct bpf_iter__wakeup_source, wakeup_source),
+			PTR_TO_BTF_ID_OR_NULL
+		},
+	},
+	.seq_info		= &wakeup_source_iter_seq_info,
+};
+
+struct bpf_iter_wakeup_source {
+	struct wakeup_source *ws;
+	int srcuidx;
+};
+
+__bpf_kfunc_start_defs();
+
+__bpf_kfunc int bpf_iter_wakeup_source_new(struct bpf_iter_wakeup_source *it)
+{
+	it->srcuidx = wakeup_sources_read_lock();
+	it->ws = wakeup_sources_walk_start();
+
+	return 0;
+}
+
+__bpf_kfunc struct wakeup_source *bpf_iter_wakeup_source_next(struct bpf_iter_wakeup_source *it)
+{
+	struct wakeup_source *prev = it->ws;
+
+	if (!prev)
+		return NULL;
+
+	it->ws = wakeup_sources_walk_next(it->ws);
+
+	return prev;
+}
+
+__bpf_kfunc void bpf_iter_wakeup_source_destroy(struct bpf_iter_wakeup_source *it)
+{
+	wakeup_sources_read_unlock(it->srcuidx);
+}
+
+__bpf_kfunc_end_defs();
+
+DEFINE_BPF_ITER_FUNC(wakeup_source, struct bpf_iter_meta *meta,
+		     struct wakeup_source *wakeup_source)
+BTF_ID_LIST_SINGLE(bpf_wakeup_source_btf_id, struct, wakeup_source)
+
+static int __init wakeup_source_iter_init(void)
+{
+	bpf_wakeup_source_reg_info.ctx_arg_info[0].btf_id = bpf_wakeup_source_btf_id[0];
+	return bpf_iter_reg_target(&bpf_wakeup_source_reg_info);
+}
+
+late_initcall(wakeup_source_iter_init);

tools/testing/selftests/bpf/bpf_experimental.h

@@ -598,6 +598,11 @@ extern void bpf_iter_dmabuf_destroy(struct bpf_iter_dmabuf *it) __weak __ksym;
 
 extern int bpf_cgroup_read_xattr(struct cgroup *cgroup, const char *name__str,
 				 struct bpf_dynptr *value_p) __weak __ksym;
+struct bpf_iter_wakeup_source;
+extern int bpf_iter_wakeup_source_new(struct bpf_iter_wakeup_source *it) __weak __ksym;
+extern struct wakeup_source *bpf_iter_wakeup_source_next(
+		struct bpf_iter_wakeup_source *it) __weak __ksym;
+extern void bpf_iter_wakeup_source_destroy(struct bpf_iter_wakeup_source *it) __weak __ksym;
 
 #define PREEMPT_BITS	8
 #define SOFTIRQ_BITS	8

tools/testing/selftests/bpf/config

@@ -111,6 +111,7 @@ CONFIG_IP6_NF_IPTABLES=y
 CONFIG_IP6_NF_FILTER=y
 CONFIG_NF_NAT=y
 CONFIG_PACKET=y
+CONFIG_PM_WAKELOCKS=y
 CONFIG_RC_CORE=y
 CONFIG_SAMPLES=y
 CONFIG_SAMPLE_LIVEPATCH=m