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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trace_event_kern.c (2314B)

      1/* Copyright (c) 2016 Facebook
      2 *
      3 * This program is free software; you can redistribute it and/or
      4 * modify it under the terms of version 2 of the GNU General Public
      5 * License as published by the Free Software Foundation.
      6 */
      7#include <linux/ptrace.h>
      8#include <uapi/linux/bpf.h>
      9#include <uapi/linux/bpf_perf_event.h>
     10#include <uapi/linux/perf_event.h>
     11#include <bpf/bpf_helpers.h>
     12#include <bpf/bpf_tracing.h>
     13
     14struct key_t {
     15	char comm[TASK_COMM_LEN];
     16	u32 kernstack;
     17	u32 userstack;
     18};
     19
     20struct {
     21	__uint(type, BPF_MAP_TYPE_HASH);
     22	__type(key, struct key_t);
     23	__type(value, u64);
     24	__uint(max_entries, 10000);
     25} counts SEC(".maps");
     26
     27struct {
     28	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
     29	__uint(key_size, sizeof(u32));
     30	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
     31	__uint(max_entries, 10000);
     32} stackmap SEC(".maps");
     33
     34#define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
     35#define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)
     36
     37SEC("perf_event")
     38int bpf_prog1(struct bpf_perf_event_data *ctx)
     39{
     40	char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu";
     41	char time_fmt2[] = "Get Time Failed, ErrCode: %d";
     42	char addr_fmt[] = "Address recorded on event: %llx";
     43	char fmt[] = "CPU-%d period %lld ip %llx";
     44	u32 cpu = bpf_get_smp_processor_id();
     45	struct bpf_perf_event_value value_buf;
     46	struct key_t key;
     47	u64 *val, one = 1;
     48	int ret;
     49
     50	if (ctx->sample_period < 10000)
     51		/* ignore warmup */
     52		return 0;
     53	bpf_get_current_comm(&key.comm, sizeof(key.comm));
     54	key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
     55	key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
     56	if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
     57		bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
     58				 PT_REGS_IP(&ctx->regs));
     59		return 0;
     60	}
     61
     62	ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value));
     63	if (!ret)
     64	  bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running);
     65	else
     66	  bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret);
     67
     68	if (ctx->addr != 0)
     69	  bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr);
     70
     71	val = bpf_map_lookup_elem(&counts, &key);
     72	if (val)
     73		(*val)++;
     74	else
     75		bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
     76	return 0;
     77}
     78
     79char _license[] SEC("license") = "GPL";