1 files changed, 138 insertions, 0 deletions
diff --git a/samples/bpf/syscall_tp_user.c b/samples/bpf/syscall_tp_user.c
new file mode 100644
index 000000000..76a1d0012
--- /dev/null
+++ b/samples/bpf/syscall_tp_user.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <errno.h>
+#include <sys/resource.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+/* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*.
+ * This requires kernel CONFIG_FTRACE_SYSCALLS to be set.
+ */
+
+static void usage(const char *cmd)
+{
+	printf("USAGE: %s [-i num_progs] [-h]\n", cmd);
+	printf("       -i num_progs      # number of progs of the test\n");
+	printf("       -h                # help\n");
+}
+
+static void verify_map(int map_id)
+{
+	__u32 key = 0;
+	__u32 val;
+
+	if (bpf_map_lookup_elem(map_id, &key, &val) != 0) {
+		fprintf(stderr, "map_lookup failed: %s\n", strerror(errno));
+		return;
+	}
+	if (val == 0) {
+		fprintf(stderr, "failed: map #%d returns value 0\n", map_id);
+		return;
+	}
+	val = 0;
+	if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {
+		fprintf(stderr, "map_update failed: %s\n", strerror(errno));
+		return;
+	}
+}
+
+static int test(char *filename, int num_progs)
+{
+	int map0_fds[num_progs], map1_fds[num_progs], fd, i, j = 0;
+	struct bpf_link *links[num_progs * 4];
+	struct bpf_object *objs[num_progs];
+	struct bpf_program *prog;
+
+	for (i = 0; i < num_progs; i++) {
+		objs[i] = bpf_object__open_file(filename, NULL);
+		if (libbpf_get_error(objs[i])) {
+			fprintf(stderr, "opening BPF object file failed\n");
+			objs[i] = NULL;
+			goto cleanup;
+		}
+
+		/* load BPF program */
+		if (bpf_object__load(objs[i])) {
+			fprintf(stderr, "loading BPF object file failed\n");
+			goto cleanup;
+		}
+
+		map0_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
+							      "enter_open_map");
+		map1_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
+							      "exit_open_map");
+		if (map0_fds[i] < 0 || map1_fds[i] < 0) {
+			fprintf(stderr, "finding a map in obj file failed\n");
+			goto cleanup;
+		}
+
+		bpf_object__for_each_program(prog, objs[i]) {
+			links[j] = bpf_program__attach(prog);
+			if (libbpf_get_error(links[j])) {
+				fprintf(stderr, "bpf_program__attach failed\n");
+				links[j] = NULL;
+				goto cleanup;
+			}
+			j++;
+		}
+		printf("prog #%d: map ids %d %d\n", i, map0_fds[i], map1_fds[i]);
+	}
+
+	/* current load_bpf_file has perf_event_open default pid = -1
+	 * and cpu = 0, which permits attached bpf execution on
+	 * all cpus for all pid's. bpf program execution ignores
+	 * cpu affinity.
+	 */
+	/* trigger some "open" operations */
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "open failed: %s\n", strerror(errno));
+		return 1;
+	}
+	close(fd);
+
+	/* verify the map */
+	for (i = 0; i < num_progs; i++) {
+		verify_map(map0_fds[i]);
+		verify_map(map1_fds[i]);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	for (i--; i >= 0; i--)
+		bpf_object__close(objs[i]);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+	int opt, num_progs = 1;
+	char filename[256];
+
+	while ((opt = getopt(argc, argv, "i:h")) != -1) {
+		switch (opt) {
+		case 'i':
+			num_progs = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			usage(argv[0]);
+			return 0;
+		}
+	}
+
+	setrlimit(RLIMIT_MEMLOCK, &r);
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	return test(filename, num_progs);
+}