cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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link_iter.c (2450B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Copyright (c) 2022 Red Hat, Inc. */
      3#include <linux/bpf.h>
      4#include <linux/fs.h>
      5#include <linux/filter.h>
      6#include <linux/kernel.h>
      7#include <linux/btf_ids.h>
      8
      9struct bpf_iter_seq_link_info {
     10	u32 link_id;
     11};
     12
     13static void *bpf_link_seq_start(struct seq_file *seq, loff_t *pos)
     14{
     15	struct bpf_iter_seq_link_info *info = seq->private;
     16	struct bpf_link *link;
     17
     18	link = bpf_link_get_curr_or_next(&info->link_id);
     19	if (!link)
     20		return NULL;
     21
     22	if (*pos == 0)
     23		++*pos;
     24	return link;
     25}
     26
     27static void *bpf_link_seq_next(struct seq_file *seq, void *v, loff_t *pos)
     28{
     29	struct bpf_iter_seq_link_info *info = seq->private;
     30
     31	++*pos;
     32	++info->link_id;
     33	bpf_link_put((struct bpf_link *)v);
     34	return bpf_link_get_curr_or_next(&info->link_id);
     35}
     36
     37struct bpf_iter__bpf_link {
     38	__bpf_md_ptr(struct bpf_iter_meta *, meta);
     39	__bpf_md_ptr(struct bpf_link *, link);
     40};
     41
     42DEFINE_BPF_ITER_FUNC(bpf_link, struct bpf_iter_meta *meta, struct bpf_link *link)
     43
     44static int __bpf_link_seq_show(struct seq_file *seq, void *v, bool in_stop)
     45{
     46	struct bpf_iter__bpf_link ctx;
     47	struct bpf_iter_meta meta;
     48	struct bpf_prog *prog;
     49	int ret = 0;
     50
     51	ctx.meta = &meta;
     52	ctx.link = v;
     53	meta.seq = seq;
     54	prog = bpf_iter_get_info(&meta, in_stop);
     55	if (prog)
     56		ret = bpf_iter_run_prog(prog, &ctx);
     57
     58	return ret;
     59}
     60
     61static int bpf_link_seq_show(struct seq_file *seq, void *v)
     62{
     63	return __bpf_link_seq_show(seq, v, false);
     64}
     65
     66static void bpf_link_seq_stop(struct seq_file *seq, void *v)
     67{
     68	if (!v)
     69		(void)__bpf_link_seq_show(seq, v, true);
     70	else
     71		bpf_link_put((struct bpf_link *)v);
     72}
     73
     74static const struct seq_operations bpf_link_seq_ops = {
     75	.start	= bpf_link_seq_start,
     76	.next	= bpf_link_seq_next,
     77	.stop	= bpf_link_seq_stop,
     78	.show	= bpf_link_seq_show,
     79};
     80
     81BTF_ID_LIST(btf_bpf_link_id)
     82BTF_ID(struct, bpf_link)
     83
     84static const struct bpf_iter_seq_info bpf_link_seq_info = {
     85	.seq_ops		= &bpf_link_seq_ops,
     86	.init_seq_private	= NULL,
     87	.fini_seq_private	= NULL,
     88	.seq_priv_size		= sizeof(struct bpf_iter_seq_link_info),
     89};
     90
     91static struct bpf_iter_reg bpf_link_reg_info = {
     92	.target			= "bpf_link",
     93	.ctx_arg_info_size	= 1,
     94	.ctx_arg_info		= {
     95		{ offsetof(struct bpf_iter__bpf_link, link),
     96		  PTR_TO_BTF_ID_OR_NULL },
     97	},
     98	.seq_info		= &bpf_link_seq_info,
     99};
    100
    101static int __init bpf_link_iter_init(void)
    102{
    103	bpf_link_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_link_id;
    104	return bpf_iter_reg_target(&bpf_link_reg_info);
    105}
    106
    107late_initcall(bpf_link_iter_init);