// SPDX-License-Identifier: GPL-2.0 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/init.h> #include <linux/module.h> #include "bpf_preload.h" #include "iterators/iterators.lskel.h" static struct bpf_link *maps_link, *progs_link; static struct iterators_bpf *skel; static void free_links_and_skel(void) { if (!IS_ERR_OR_NULL(maps_link)) bpf_link_put(maps_link); if (!IS_ERR_OR_NULL(progs_link)) bpf_link_put(progs_link); iterators_bpf__destroy(skel); } static int preload(struct bpf_preload_info *obj) { strlcpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name)); obj[0].link = maps_link; strlcpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name)); obj[1].link = progs_link; return 0; } static struct bpf_preload_ops ops = { .preload = preload, .owner = THIS_MODULE, }; static int load_skel(void) { int err; skel = iterators_bpf__open(); if (!skel) return -ENOMEM; err = iterators_bpf__load(skel); if (err) goto out; err = iterators_bpf__attach(skel); if (err) goto out; maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd); if (IS_ERR(maps_link)) { err = PTR_ERR(maps_link); goto out; } progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd); if (IS_ERR(progs_link)) { err = PTR_ERR(progs_link); goto out; } /* Avoid taking over stdin/stdout/stderr of init process. Zeroing out * makes skel_closenz() a no-op later in iterators_bpf__destroy(). */ close_fd(skel->links.dump_bpf_map_fd); skel->links.dump_bpf_map_fd = 0; close_fd(skel->links.dump_bpf_prog_fd); skel->links.dump_bpf_prog_fd = 0; return 0; out: free_links_and_skel(); return err; } static int __init load(void) { int err; err = load_skel(); if (err) return err; bpf_preload_ops = &ops; return err; } static void __exit fini(void) { bpf_preload_ops = NULL; free_links_and_skel(); } late_initcall(load); module_exit(fini); MODULE_LICENSE("GPL");