1 // SPDX-License-Identifier: GPL-2.0
2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include "bpf_preload.h"
6 #include "iterators/iterators.lskel.h"
8 static struct bpf_link *maps_link, *progs_link;
9 static struct iterators_bpf *skel;
11 static void free_links_and_skel(void)
13 if (!IS_ERR_OR_NULL(maps_link))
14 bpf_link_put(maps_link);
15 if (!IS_ERR_OR_NULL(progs_link))
16 bpf_link_put(progs_link);
17 iterators_bpf__destroy(skel);
20 static int preload(struct bpf_preload_info *obj)
22 strlcpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
23 obj[0].link = maps_link;
24 strlcpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
25 obj[1].link = progs_link;
29 static struct bpf_preload_ops ops = {
34 static int load_skel(void)
38 skel = iterators_bpf__open();
41 err = iterators_bpf__load(skel);
44 err = iterators_bpf__attach(skel);
47 maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd);
48 if (IS_ERR(maps_link)) {
49 err = PTR_ERR(maps_link);
52 progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd);
53 if (IS_ERR(progs_link)) {
54 err = PTR_ERR(progs_link);
57 /* Avoid taking over stdin/stdout/stderr of init process. Zeroing out
58 * makes skel_closenz() a no-op later in iterators_bpf__destroy().
60 close_fd(skel->links.dump_bpf_map_fd);
61 skel->links.dump_bpf_map_fd = 0;
62 close_fd(skel->links.dump_bpf_prog_fd);
63 skel->links.dump_bpf_prog_fd = 0;
66 free_links_and_skel();
70 static int __init load(void)
77 bpf_preload_ops = &ops;
81 static void __exit fini(void)
83 bpf_preload_ops = NULL;
84 free_links_and_skel();
88 MODULE_LICENSE("GPL");