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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test_core_retro.c (1005B)

      1// SPDX-License-Identifier: GPL-2.0
      2// Copyright (c) 2020 Facebook
      3#include <linux/bpf.h>
      4#include <bpf/bpf_helpers.h>
      5#include <bpf/bpf_core_read.h>
      6
      7struct task_struct {
      8	int tgid;
      9} __attribute__((preserve_access_index));
     10
     11struct {
     12	__uint(type, BPF_MAP_TYPE_ARRAY);
     13	__uint(max_entries, 1);
     14	__type(key, int);
     15	__type(value, int);
     16} exp_tgid_map SEC(".maps");
     17
     18struct {
     19	__uint(type, BPF_MAP_TYPE_ARRAY);
     20	__uint(max_entries, 1);
     21	__type(key, int);
     22	__type(value, int);
     23} results SEC(".maps");
     24
     25SEC("tp/raw_syscalls/sys_enter")
     26int handle_sys_enter(void *ctx)
     27{
     28	struct task_struct *task = (void *)bpf_get_current_task();
     29	int tgid = BPF_CORE_READ(task, tgid);
     30	int zero = 0;
     31	int real_tgid = bpf_get_current_pid_tgid() >> 32;
     32	int *exp_tgid = bpf_map_lookup_elem(&exp_tgid_map, &zero);
     33
     34	/* only pass through sys_enters from test process */
     35	if (!exp_tgid || *exp_tgid != real_tgid)
     36		return 0;
     37
     38	bpf_map_update_elem(&results, &zero, &tgid, 0);
     39
     40	return 0;
     41}
     42
     43char _license[] SEC("license") = "GPL";