Add a BPF iterator for traversing through wakeup_sources. Setup iterators to traverse through a SRCUs of wakeup_sources. This is a more elegant and efficient traversal than going through the options today, such as at /sys/class/wakeup, or through debugfs. Signed-off-by: Samuel Wu --- kernel/bpf/Makefile | 3 + kernel/bpf/wakeup_source_iter.c | 103 ++++++++++++++++++++++++++++++++ 2 files changed, 106 insertions(+) create mode 100644 kernel/bpf/wakeup_source_iter.c diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 79cf22860a99..1259373298e1 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -66,6 +66,9 @@ obj-$(CONFIG_BPF_SYSCALL) += kmem_cache_iter.o ifeq ($(CONFIG_DMA_SHARED_BUFFER),y) obj-$(CONFIG_BPF_SYSCALL) += dmabuf_iter.o endif +ifeq ($(CONFIG_PM_SLEEP),y) +obj-$(CONFIG_BPF_SYSCALL) += wakeup_source_iter.o +endif CFLAGS_REMOVE_percpu_freelist.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_bpf_lru_list.o = $(CC_FLAGS_FTRACE) diff --git a/kernel/bpf/wakeup_source_iter.c b/kernel/bpf/wakeup_source_iter.c new file mode 100644 index 000000000000..ab83d212a1f9 --- /dev/null +++ b/kernel/bpf/wakeup_source_iter.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2026 Google LLC */ +#include +#include +#include +#include +#include + +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, +}; + +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); -- 2.53.0.473.g4a7958ca14-goog Sets up the framework to test wakeup_sources iterators using BPF, and adds a few basic tests. Adds several helper functions that for grabbing and releasing a wakelock, abstracting out key functions to setup a framework for testing wakeup_sources. Additionally, adds 3 tests: 1. check_active_count: Checks that stats related to active_count are properly set after several lock/unlock cycles 2. check_sleep_times: Checks that time accounting related to sleep are properly calculated 3. check_no_infinite_reads: Checks that the iterator traversal returns NULL at the end Signed-off-by: Samuel Wu --- tools/testing/selftests/bpf/config | 1 + .../bpf/prog_tests/wakeup_source_iter.c | 300 ++++++++++++++++++ .../selftests/bpf/progs/wakeup_source_iter.c | 80 +++++ 3 files changed, 381 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/wakeup_source_iter.c create mode 100644 tools/testing/selftests/bpf/progs/wakeup_source_iter.c diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index 24855381290d..75e8542ef111 100644 --- a/tools/testing/selftests/bpf/config +++ b/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 diff --git a/tools/testing/selftests/bpf/prog_tests/wakeup_source_iter.c b/tools/testing/selftests/bpf/prog_tests/wakeup_source_iter.c new file mode 100644 index 000000000000..40e47157a6a0 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/wakeup_source_iter.c @@ -0,0 +1,300 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Google LLC */ + +#include +#include +#include +#include "wakeup_source_iter.skel.h" + +#include +#include +#include +#include +#include +#include + + +/* Sleep for 10ms to ensure active time is > 0 after converting ns to ms*/ +#define TEST_SLEEP_US 10000 +#define TEST_SLEEP_MS (TEST_SLEEP_US / 1000) +#define WAKEUP_SOURCE_NAME_LEN 32 + +static const char test_ws_name[] = "bpf_selftest_ws"; +static bool test_ws_created; + +/* + * Creates a new wakeup source by writing to /sys/power/wake_lock. + * This lock persists until explicitly unlocked. + */ +static int lock_ws(const char *name) +{ + int fd; + ssize_t bytes; + + fd = open("/sys/power/wake_lock", O_WRONLY); + if (!ASSERT_OK_FD(fd, "open /sys/power/wake_lock")) + return -1; + + bytes = write(fd, name, strlen(name)); + close(fd); + if (!ASSERT_EQ(bytes, strlen(name), "write to wake_lock")) + return -1; + + return 0; +} + +/* + * Destroys the ws by writing the same name to /sys/power/wake_unlock. + */ +static void unlock_ws(const char *name) +{ + int fd; + + fd = open("/sys/power/wake_unlock", O_WRONLY); + if (!ASSERT_OK_FD(fd, "open /sys/power/wake_unlock")) + goto cleanup; + + write(fd, name, strlen(name)); + +cleanup: + if (fd) + close(fd); +} + +/* + * Setups for testing ws iterators. Will run once prior to suite of tests. + */ +static int setup_test_ws(void) +{ + if (lock_ws(test_ws_name)) + return -1; + test_ws_created = true; + + return 0; +} + +/* + * Tears down and cleanups testing ws iterators. WIll run once after the suite + * of tests. + */ +static void teardown_test_ws(void) +{ + if (!test_ws_created) + return; + unlock_ws(test_ws_name); + test_ws_created = false; +} + +struct WakeupSourceInfo { + char name[WAKEUP_SOURCE_NAME_LEN]; + unsigned long active_count; + long active_time_ms; + unsigned long event_count; + unsigned long expire_count; + long last_change_ms; + long max_time_ms; + long prevent_sleep_time_ms; + long total_time_ms; + unsigned long wakeup_count; +}; + +/* + * Reads and parses one wakeup_source record from the iterator file. + * A record is a single space-delimited line. + * Returns true on success, false on EOF. Asserts internally on errors. + */ +static bool read_ws_info(FILE *iter_file, struct WakeupSourceInfo *ws_info, + char **line) +{ + size_t linesize; + int items; + + if (getline(line, &linesize, iter_file) == -1) + return false; + + (*line)[strcspn(*line, "\n")] = 0; + + items = sscanf(*line, "%s %lu %ld %lu %lu %ld %ld %ld %ld %lu", + ws_info->name, &ws_info->active_count, + &ws_info->active_time_ms, &ws_info->event_count, + &ws_info->expire_count, &ws_info->last_change_ms, + &ws_info->max_time_ms, &ws_info->prevent_sleep_time_ms, + &ws_info->total_time_ms, &ws_info->wakeup_count); + + if (!ASSERT_EQ(items, 10, "read wakeup source info")) + return false; + + if (!ASSERT_LT(strlen(ws_info->name), WAKEUP_SOURCE_NAME_LEN, + "name length")) + return false; + + return true; +} + +static int get_ws_iter_stream(struct wakeup_source_iter *skel, int *iter_fd, + FILE **iter_file) +{ + *iter_fd = bpf_iter_create( + bpf_link__fd(skel->links.wakeup_source_collector)); + if (!ASSERT_OK_FD(*iter_fd, "iter_create")) + return -1; + + *iter_file = fdopen(*iter_fd, "r"); + if (!ASSERT_OK_PTR(*iter_file, "fdopen")) + return -1; + + return 0; +} + +static void subtest_ws_iter_check_active_count(struct wakeup_source_iter *skel) +{ + static const char subtest_ws_name[] = "bpf_selftest_ws_active_count"; + const int lock_unlock_cycles = 5; + struct WakeupSourceInfo ws_info; + char *line = NULL; + bool found_ws = false; + FILE *iter_file = NULL; + int iter_fd = -1; + int i; + + for (i = 0; i < lock_unlock_cycles; i++) { + if (!ASSERT_OK(lock_ws(subtest_ws_name), "lock_ws")) + goto cleanup; + unlock_ws(subtest_ws_name); + } + + if (get_ws_iter_stream(skel, &iter_fd, &iter_file)) + goto cleanup; + + while (read_ws_info(iter_file, &ws_info, &line)) { + if (strcmp(ws_info.name, subtest_ws_name) == 0) { + found_ws = true; + ASSERT_EQ(ws_info.active_count, lock_unlock_cycles, + "active_count check"); + ASSERT_EQ(ws_info.event_count, lock_unlock_cycles, + "event_count check"); + break; + } + } + + ASSERT_TRUE(found_ws, "found active_count test ws"); + + free(line); +cleanup: + if (iter_file) + fclose(iter_file); + else if (iter_fd >= 0) + close(iter_fd); +} + +static void subtest_ws_iter_check_sleep_times(struct wakeup_source_iter *skel) +{ + bool found_test_ws = false; + struct WakeupSourceInfo ws_info; + char *line = NULL; + FILE *iter_file = NULL; + int iter_fd = -1; + + if (get_ws_iter_stream(skel, &iter_fd, &iter_file)) + goto cleanup; + + while (read_ws_info(iter_file, &ws_info, &line)) { + if (strcmp(ws_info.name, test_ws_name) == 0) { + found_test_ws = true; + ASSERT_GT(ws_info.last_change_ms, 0, + "Expected non-zero last change"); + ASSERT_GE(ws_info.active_time_ms, TEST_SLEEP_MS, + "Expected active time >= TEST_SLEEP_MS"); + ASSERT_GE(ws_info.max_time_ms, TEST_SLEEP_MS, + "Expected max time >= TEST_SLEEP_MS"); + ASSERT_GE(ws_info.total_time_ms, TEST_SLEEP_MS, + "Expected total time >= TEST_SLEEP_MS"); + break; + } + } + + ASSERT_TRUE(found_test_ws, "found_test_ws"); + + free(line); +cleanup: + if (iter_file) + fclose(iter_file); + else if (iter_fd >= 0) + close(iter_fd); +} + +static void subtest_ws_iter_check_no_infinite_reads( + struct wakeup_source_iter *skel) +{ + int iter_fd; + char buf[256]; + + iter_fd = bpf_iter_create(bpf_link__fd(skel->links.wakeup_source_collector)); + if (!ASSERT_OK_FD(iter_fd, "iter_create")) + return; + + while (read(iter_fd, buf, sizeof(buf)) > 0) + ; + + /* Final read should return 0 */ + ASSERT_EQ(read(iter_fd, buf, sizeof(buf)), 0, "read"); + + close(iter_fd); +} + +void test_wakeup_source_iter(void) +{ + struct wakeup_source_iter *skel = NULL; + struct btf *vmlinux_btf; + int btf_id; + + if (geteuid() != 0) { + fprintf(stderr, + "Skipping wakeup_source_iter test, requires root\n"); + test__skip(); + return; + } + + skel = wakeup_source_iter__open(); + if (!ASSERT_OK_PTR(skel, "wakeup_source_iter__open")) + return; + + vmlinux_btf = btf__load_vmlinux_btf(); + if (!vmlinux_btf) + return; + + btf_id = btf__find_by_name_kind(vmlinux_btf, "bpf_iter__wakeup_source", BTF_KIND_STRUCT); + btf__free(vmlinux_btf); + + if (btf_id <= 0) { + test__skip(); + goto destroy; + } + + if (!ASSERT_OK(wakeup_source_iter__load(skel), "iter__load")) + goto destroy; + + if (!ASSERT_OK(setup_test_ws(), "setup_test_ws")) + goto teardown; + + if (!ASSERT_OK(wakeup_source_iter__attach(skel), "skel_attach")) + goto teardown; + + /* + * Sleep on O(ms) to ensure that time stats' resolution isn't lost when + * converting from ns to ms + */ + usleep(TEST_SLEEP_US); + + if (test__start_subtest("active_count")) + subtest_ws_iter_check_active_count(skel); + if (test__start_subtest("sleep_times")) + subtest_ws_iter_check_sleep_times(skel); + if (test__start_subtest("no_infinite_reads")) + subtest_ws_iter_check_no_infinite_reads(skel); + +teardown: + teardown_test_ws(); +destroy: + wakeup_source_iter__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/wakeup_source_iter.c b/tools/testing/selftests/bpf/progs/wakeup_source_iter.c new file mode 100644 index 000000000000..d770efc3bd0d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/wakeup_source_iter.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Google LLC */ +#include +#include +#include + +#define NSEC_PER_MS 1000000UL +#define WAKEUP_SOURCE_NAME_LEN 32 + +char _license[] SEC("license") = "GPL"; + +struct wakeup_source___local { + const char *name; + unsigned long active_count; + unsigned long event_count; + unsigned long wakeup_count; + unsigned long expire_count; + ktime_t last_time; + ktime_t max_time; + ktime_t total_time; + ktime_t start_prevent_time; + ktime_t prevent_sleep_time; + bool active:1; + bool autosleep_enabled:1; +} __attribute__((preserve_access_index)); + +struct bpf_iter__wakeup_source___local { + struct bpf_iter_meta *meta; + struct wakeup_source___local *wakeup_source; +} __attribute__((preserve_access_index)); + +SEC("iter/wakeup_source") +int wakeup_source_collector(struct bpf_iter__wakeup_source___local *ctx) +{ + const struct wakeup_source___local *ws = ctx->wakeup_source; + struct seq_file *seq = ctx->meta->seq; + char name[WAKEUP_SOURCE_NAME_LEN] = {'\0'}; + const char *pname; + bool active, autosleep_enable; + s64 active_time, curr_time, max_time, prevent_sleep_time, total_time; + + if (!ws) + return 0; + + active = BPF_CORE_READ_BITFIELD_PROBED(ws, active); + autosleep_enable = BPF_CORE_READ_BITFIELD_PROBED(ws, autosleep_enabled); + if (bpf_core_read(&pname, sizeof(pname), &ws->name) || + bpf_probe_read_kernel_str(name, sizeof(name), pname) < 0) + return 0; + + active_time = 0; + curr_time = bpf_ktime_get_ns(); + max_time = ws->max_time; + prevent_sleep_time = ws->prevent_sleep_time; + total_time = ws->total_time; + + if (active) { + active_time = curr_time - ws->last_time; + total_time += active_time; + if (active_time > max_time) + max_time = active_time; + if (autosleep_enable) + prevent_sleep_time += + curr_time - ws->start_prevent_time; + } + + BPF_SEQ_PRINTF(seq, + "%s %lu %ld %lu %lu %ld %ld %ld %ld %lu\n", + name, + ws->active_count, + active_time / NSEC_PER_MS, + ws->event_count, + ws->expire_count, + ws->last_time / NSEC_PER_MS, + max_time / NSEC_PER_MS, + prevent_sleep_time / NSEC_PER_MS, + total_time / NSEC_PER_MS, + ws->wakeup_count); + return 0; +} -- 2.53.0.473.g4a7958ca14-goog