cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

bpf_preload_kern.c (1924B)

      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"
      7
      8static struct bpf_link *maps_link, *progs_link;
      9static struct iterators_bpf *skel;
     10
     11static void free_links_and_skel(void)
     12{
     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);
     18}
     19
     20static int preload(struct bpf_preload_info *obj)
     21{
     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;
     26	return 0;
     27}
     28
     29static struct bpf_preload_ops ops = {
     30	.preload = preload,
     31	.owner = THIS_MODULE,
     32};
     33
     34static int load_skel(void)
     35{
     36	int err;
     37
     38	skel = iterators_bpf__open();
     39	if (!skel)
     40		return -ENOMEM;
     41	err = iterators_bpf__load(skel);
     42	if (err)
     43		goto out;
     44	err = iterators_bpf__attach(skel);
     45	if (err)
     46		goto out;
     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);
     50		goto out;
     51	}
     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);
     55		goto out;
     56	}
     57	/* Avoid taking over stdin/stdout/stderr of init process. Zeroing out
     58	 * makes skel_closenz() a no-op later in iterators_bpf__destroy().
     59	 */
     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;
     64	return 0;
     65out:
     66	free_links_and_skel();
     67	return err;
     68}
     69
     70static int __init load(void)
     71{
     72	int err;
     73
     74	err = load_skel();
     75	if (err)
     76		return err;
     77	bpf_preload_ops = &ops;
     78	return err;
     79}
     80
     81static void __exit fini(void)
     82{
     83	bpf_preload_ops = NULL;
     84	free_links_and_skel();
     85}
     86late_initcall(load);
     87module_exit(fini);
     88MODULE_LICENSE("GPL");