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 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
7 #include "iterators/iterators.lskel-little-endian.h"
9 #include "iterators/iterators.lskel-big-endian.h"
12 static struct bpf_link *maps_link, *progs_link;
13 static struct iterators_bpf *skel;
15 static void free_links_and_skel(void)
17 if (!IS_ERR_OR_NULL(maps_link))
18 bpf_link_put(maps_link);
19 if (!IS_ERR_OR_NULL(progs_link))
20 bpf_link_put(progs_link);
21 iterators_bpf__destroy(skel);
24 static int preload(struct bpf_preload_info *obj)
26 strscpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
27 obj[0].link = maps_link;
28 strscpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
29 obj[1].link = progs_link;
33 static struct bpf_preload_ops ops = {
38 static int load_skel(void)
42 skel = iterators_bpf__open();
45 err = iterators_bpf__load(skel);
48 err = iterators_bpf__attach(skel);
51 maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd);
52 if (IS_ERR(maps_link)) {
53 err = PTR_ERR(maps_link);
56 progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd);
57 if (IS_ERR(progs_link)) {
58 err = PTR_ERR(progs_link);
61 /* Avoid taking over stdin/stdout/stderr of init process. Zeroing out
62 * makes skel_closenz() a no-op later in iterators_bpf__destroy().
64 close_fd(skel->links.dump_bpf_map_fd);
65 skel->links.dump_bpf_map_fd = 0;
66 close_fd(skel->links.dump_bpf_prog_fd);
67 skel->links.dump_bpf_prog_fd = 0;
70 free_links_and_skel();
74 static int __init load(void)
81 bpf_preload_ops = &ops;
85 static void __exit fini(void)
87 bpf_preload_ops = NULL;
88 free_links_and_skel();
92 MODULE_LICENSE("GPL");