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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /samples/bpf/test_current_task_under_cgroup_user.c
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/test_current_task_under_cgroup_user.c')
-rw-r--r--samples/bpf/test_current_task_under_cgroup_user.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/samples/bpf/test_current_task_under_cgroup_user.c b/samples/bpf/test_current_task_under_cgroup_user.c
new file mode 100644
index 000000000..ac251a417
--- /dev/null
+++ b/samples/bpf/test_current_task_under_cgroup_user.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Sargun Dhillon <sargun@sargun.me>
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "cgroup_helpers.h"
+
+#define CGROUP_PATH "/my-cgroup"
+
+int main(int argc, char **argv)
+{
+ pid_t remote_pid, local_pid = getpid();
+ struct bpf_link *link = NULL;
+ struct bpf_program *prog;
+ int cg2, idx = 0, rc = 1;
+ struct bpf_object *obj;
+ char filename[256];
+ int map_fd[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");
+ return 0;
+ }
+
+ prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+ if (!prog) {
+ printf("finding a prog in obj file failed\n");
+ 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, "cgroup_map");
+ map_fd[1] = bpf_object__find_map_fd_by_name(obj, "perf_map");
+ if (map_fd[0] < 0 || map_fd[1] < 0) {
+ fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+ goto cleanup;
+ }
+
+ link = bpf_program__attach(prog);
+ if (libbpf_get_error(link)) {
+ fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+ link = NULL;
+ goto cleanup;
+ }
+
+ if (setup_cgroup_environment())
+ goto err;
+
+ cg2 = create_and_get_cgroup(CGROUP_PATH);
+
+ if (cg2 < 0)
+ goto err;
+
+ if (bpf_map_update_elem(map_fd[0], &idx, &cg2, BPF_ANY)) {
+ log_err("Adding target cgroup to map");
+ goto err;
+ }
+
+ if (join_cgroup(CGROUP_PATH))
+ goto err;
+
+ /*
+ * The installed helper program catched the sync call, and should
+ * write it to the map.
+ */
+
+ sync();
+ bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
+
+ if (local_pid != remote_pid) {
+ fprintf(stderr,
+ "BPF Helper didn't write correct PID to map, but: %d\n",
+ remote_pid);
+ goto err;
+ }
+
+ /* Verify the negative scenario; leave the cgroup */
+ if (join_cgroup("/"))
+ goto err;
+
+ remote_pid = 0;
+ bpf_map_update_elem(map_fd[1], &idx, &remote_pid, BPF_ANY);
+
+ sync();
+ bpf_map_lookup_elem(map_fd[1], &idx, &remote_pid);
+
+ if (local_pid == remote_pid) {
+ fprintf(stderr, "BPF cgroup negative test did not work\n");
+ goto err;
+ }
+
+ rc = 0;
+
+err:
+ close(cg2);
+ cleanup_cgroup_environment();
+
+cleanup:
+ bpf_link__destroy(link);
+ bpf_object__close(obj);
+ return rc;
+}