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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timer_mim.c (2013B)

      1// SPDX-License-Identifier: GPL-2.0
      2/* Copyright (c) 2021 Facebook */
      3#include <linux/bpf.h>
      4#include <time.h>
      5#include <errno.h>
      6#include <bpf/bpf_helpers.h>
      7#include "bpf_tcp_helpers.h"
      8
      9char _license[] SEC("license") = "GPL";
     10struct hmap_elem {
     11	int pad; /* unused */
     12	struct bpf_timer timer;
     13};
     14
     15struct inner_map {
     16	__uint(type, BPF_MAP_TYPE_HASH);
     17	__uint(max_entries, 1024);
     18	__type(key, int);
     19	__type(value, struct hmap_elem);
     20} inner_htab SEC(".maps");
     21
     22#define ARRAY_KEY 1
     23#define HASH_KEY 1234
     24
     25struct outer_arr {
     26	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
     27	__uint(max_entries, 2);
     28	__uint(key_size, sizeof(int));
     29	__uint(value_size, sizeof(int));
     30	__array(values, struct inner_map);
     31} outer_arr SEC(".maps") = {
     32	.values = { [ARRAY_KEY] = &inner_htab },
     33};
     34
     35__u64 err;
     36__u64 ok;
     37__u64 cnt;
     38
     39static int timer_cb1(void *map, int *key, struct hmap_elem *val);
     40
     41static int timer_cb2(void *map, int *key, struct hmap_elem *val)
     42{
     43	cnt++;
     44	bpf_timer_set_callback(&val->timer, timer_cb1);
     45	if (bpf_timer_start(&val->timer, 1000, 0))
     46		err |= 1;
     47	ok |= 1;
     48	return 0;
     49}
     50
     51/* callback for inner hash map */
     52static int timer_cb1(void *map, int *key, struct hmap_elem *val)
     53{
     54	cnt++;
     55	bpf_timer_set_callback(&val->timer, timer_cb2);
     56	if (bpf_timer_start(&val->timer, 1000, 0))
     57		err |= 2;
     58	/* Do a lookup to make sure 'map' and 'key' pointers are correct */
     59	bpf_map_lookup_elem(map, key);
     60	ok |= 2;
     61	return 0;
     62}
     63
     64SEC("fentry/bpf_fentry_test1")
     65int BPF_PROG(test1, int a)
     66{
     67	struct hmap_elem init = {};
     68	struct bpf_map *inner_map;
     69	struct hmap_elem *val;
     70	int array_key = ARRAY_KEY;
     71	int hash_key = HASH_KEY;
     72
     73	inner_map = bpf_map_lookup_elem(&outer_arr, &array_key);
     74	if (!inner_map)
     75		return 0;
     76
     77	bpf_map_update_elem(inner_map, &hash_key, &init, 0);
     78	val = bpf_map_lookup_elem(inner_map, &hash_key);
     79	if (!val)
     80		return 0;
     81
     82	bpf_timer_init(&val->timer, inner_map, CLOCK_MONOTONIC);
     83	if (bpf_timer_set_callback(&val->timer, timer_cb1))
     84		err |= 4;
     85	if (bpf_timer_start(&val->timer, 0, 0))
     86		err |= 8;
     87	return 0;
     88}