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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for_each_array_map_elem.c (1472B)

      1// SPDX-License-Identifier: GPL-2.0
      2/* Copyright (c) 2021 Facebook */
      3#include "vmlinux.h"
      4#include <bpf/bpf_helpers.h>
      5
      6char _license[] SEC("license") = "GPL";
      7
      8struct {
      9	__uint(type, BPF_MAP_TYPE_ARRAY);
     10	__uint(max_entries, 3);
     11	__type(key, __u32);
     12	__type(value, __u64);
     13} arraymap SEC(".maps");
     14
     15struct {
     16	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
     17	__uint(max_entries, 1);
     18	__type(key, __u32);
     19	__type(value, __u64);
     20} percpu_map SEC(".maps");
     21
     22struct callback_ctx {
     23	int output;
     24};
     25
     26const volatile int bypass_unused = 1;
     27
     28static __u64
     29unused_subprog(struct bpf_map *map, __u32 *key, __u64 *val,
     30	       struct callback_ctx *data)
     31{
     32	data->output = 0;
     33	return 1;
     34}
     35
     36static __u64
     37check_array_elem(struct bpf_map *map, __u32 *key, __u64 *val,
     38		 struct callback_ctx *data)
     39{
     40	data->output += *val;
     41	if (*key == 1)
     42		return 1; /* stop the iteration */
     43	return 0;
     44}
     45
     46__u32 cpu = 0;
     47__u64 percpu_val = 0;
     48
     49static __u64
     50check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val,
     51		  struct callback_ctx *data)
     52{
     53	cpu = bpf_get_smp_processor_id();
     54	percpu_val = *val;
     55	return 0;
     56}
     57
     58u32 arraymap_output = 0;
     59
     60SEC("tc")
     61int test_pkt_access(struct __sk_buff *skb)
     62{
     63	struct callback_ctx data;
     64
     65	data.output = 0;
     66	bpf_for_each_map_elem(&arraymap, check_array_elem, &data, 0);
     67	if (!bypass_unused)
     68		bpf_for_each_map_elem(&arraymap, unused_subprog, &data, 0);
     69	arraymap_output = data.output;
     70
     71	bpf_for_each_map_elem(&percpu_map, check_percpu_elem, (void *)0, 0);
     72	return 0;
     73}