| 1 | |
| 2 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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| 3 | #include <linux/init.h>
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| 4 | #include <linux/module.h>
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| 5 | #include "bpf_preload.h"
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| 6 | #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
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| 7 | #include "iterators/iterators.lskel-little-endian.h"
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| 8 | #else
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| 9 | #include "iterators/iterators.lskel-big-endian.h"
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| 10 | #endif
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| 11 |
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| 12 | static struct bpf_link *maps_link, *progs_link;
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| 13 | static struct iterators_bpf *skel;
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| 14 |
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| 15 | static void free_links_and_skel(void)
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| 16 | {
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| 17 | if (!IS_ERR_OR_NULL(maps_link))
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| 18 | bpf_link_put(maps_link);
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| 19 | if (!IS_ERR_OR_NULL(progs_link))
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| 20 | bpf_link_put(progs_link);
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| 21 | iterators_bpf__destroy(skel);
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| 22 | }
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| 23 |
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| 24 | static int preload(struct bpf_preload_info *obj)
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| 25 | {
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| 26 | strscpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
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| 27 | obj[0].link = maps_link;
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| 28 | strscpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
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| 29 | obj[1].link = progs_link;
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| 30 | return 0;
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| 31 | }
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| 32 |
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| 33 | static struct bpf_preload_ops ops = {
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| 34 | .preload = preload,
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| 35 | .owner = THIS_MODULE,
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| 36 | };
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| 37 |
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| 38 | static int load_skel(void)
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| 39 | {
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| 40 | int err;
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| 41 |
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| 42 | skel = iterators_bpf__open();
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| 43 | if (!skel)
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| 44 | return -ENOMEM;
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| 45 | err = iterators_bpf__load(skel);
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| 46 | if (err)
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| 47 | goto out;
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| 48 | err = iterators_bpf__attach(skel);
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| 49 | if (err)
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| 50 | goto out;
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| 51 | maps_link = bpf_link_get_from_fd(skel->links.dump_bpf_map_fd);
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| 52 | if (IS_ERR(maps_link)) {
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| 53 | err = PTR_ERR(maps_link);
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| 54 | goto out;
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| 55 | }
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| 56 | progs_link = bpf_link_get_from_fd(skel->links.dump_bpf_prog_fd);
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| 57 | if (IS_ERR(progs_link)) {
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| 58 | err = PTR_ERR(progs_link);
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| 59 | goto out;
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| 60 | }
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| 61 | |
| 62 | * makes skel_closenz() a no-op later in iterators_bpf__destroy().
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| 63 |
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| 64 | close_fd(skel->links.dump_bpf_map_fd);
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| 65 | skel->links.dump_bpf_map_fd = 0;
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| 66 | close_fd(skel->links.dump_bpf_prog_fd);
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| 67 | skel->links.dump_bpf_prog_fd = 0;
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| 68 | return 0;
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| 69 | out:
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| 70 | free_links_and_skel();
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| 71 | return err;
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| 72 | }
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| 73 |
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| 74 | static int __init load(void)
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| 75 | {
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| 76 | int err;
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| 77 |
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| 78 | err = load_skel();
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| 79 | if (err)
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| 80 | return err;
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| 81 | bpf_preload_ops = &ops;
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| 82 | return err;
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| 83 | }
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| 84 |
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| 85 | static void __exit fini(void)
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| 86 | {
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| 87 | bpf_preload_ops = NULL;
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| 88 | free_links_and_skel();
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| 89 | }
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| 90 | late_initcall(load);
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| 91 | module_exit(fini);
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| 92 | MODULE_IMPORT_NS("BPF_INTERNAL");
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| 93 | MODULE_LICENSE("GPL");
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| 94 | MODULE_DESCRIPTION("Embedded BPF programs for introspection in bpffs");
|