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-rw-r--r--samples/bpf/offwaketime_user.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c
new file mode 100644
index 000000000..b6eedcb98
--- /dev/null
+++ b/samples/bpf/offwaketime_user.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <linux/perf_event.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "trace_helpers.h"
+
+#define PRINT_RAW_ADDR 0
+
+/* counts, stackmap */
+static int map_fd[2];
+
+static void print_ksym(__u64 addr)
+{
+ struct ksym *sym;
+
+ if (!addr)
+ return;
+ sym = ksym_search(addr);
+ if (!sym) {
+ printf("ksym not found. Is kallsyms loaded?\n");
+ return;
+ }
+
+ if (PRINT_RAW_ADDR)
+ printf("%s/%llx;", sym->name, addr);
+ else
+ printf("%s;", sym->name);
+}
+
+#define TASK_COMM_LEN 16
+
+struct key_t {
+ char waker[TASK_COMM_LEN];
+ char target[TASK_COMM_LEN];
+ __u32 wret;
+ __u32 tret;
+};
+
+static void print_stack(struct key_t *key, __u64 count)
+{
+ __u64 ip[PERF_MAX_STACK_DEPTH] = {};
+ static bool warned;
+ int i;
+
+ printf("%s;", key->target);
+ if (bpf_map_lookup_elem(map_fd[1], &key->tret, ip) != 0) {
+ printf("---;");
+ } else {
+ for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+ print_ksym(ip[i]);
+ }
+ printf("-;");
+ if (bpf_map_lookup_elem(map_fd[1], &key->wret, ip) != 0) {
+ printf("---;");
+ } else {
+ for (i = 0; i < PERF_MAX_STACK_DEPTH; i++)
+ print_ksym(ip[i]);
+ }
+ printf(";%s %lld\n", key->waker, count);
+
+ if ((key->tret == -EEXIST || key->wret == -EEXIST) && !warned) {
+ printf("stackmap collisions seen. Consider increasing size\n");
+ warned = true;
+ } else if (((int)(key->tret) < 0 || (int)(key->wret) < 0)) {
+ printf("err stackid %d %d\n", key->tret, key->wret);
+ }
+}
+
+static void print_stacks(int fd)
+{
+ struct key_t key = {}, next_key;
+ __u64 value;
+
+ while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+ bpf_map_lookup_elem(fd, &next_key, &value);
+ print_stack(&next_key, value);
+ key = next_key;
+ }
+}
+
+static void int_exit(int sig)
+{
+ print_stacks(map_fd[0]);
+ exit(0);
+}
+
+int main(int argc, char **argv)
+{
+ struct bpf_object *obj = NULL;
+ struct bpf_link *links[2];
+ struct bpf_program *prog;
+ int delay = 1, i = 0;
+ char filename[256];
+
+ if (load_kallsyms()) {
+ printf("failed to process /proc/kallsyms\n");
+ return 2;
+ }
+
+ snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+ obj = bpf_object__open_file(filename, NULL);
+ if (libbpf_get_error(obj)) {
+ fprintf(stderr, "ERROR: opening BPF object file failed\n");
+ obj = NULL;
+ goto cleanup;
+ }
+
+ /* load BPF program */
+ if (bpf_object__load(obj)) {
+ fprintf(stderr, "ERROR: loading BPF object file failed\n");
+ goto cleanup;
+ }
+
+ map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
+ map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
+ if (map_fd[0] < 0 || map_fd[1] < 0) {
+ fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+ goto cleanup;
+ }
+
+ signal(SIGINT, int_exit);
+ signal(SIGTERM, int_exit);
+
+ bpf_object__for_each_program(prog, obj) {
+ links[i] = bpf_program__attach(prog);
+ if (libbpf_get_error(links[i])) {
+ fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+ links[i] = NULL;
+ goto cleanup;
+ }
+ i++;
+ }
+
+ if (argc > 1)
+ delay = atoi(argv[1]);
+ sleep(delay);
+ print_stacks(map_fd[0]);
+
+cleanup:
+ for (i--; i >= 0; i--)
+ bpf_link__destroy(links[i]);
+
+ bpf_object__close(obj);
+ return 0;
+}