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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offwaketime_user.c (3241B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Copyright (c) 2016 Facebook
      3 */
      4#include <stdio.h>
      5#include <unistd.h>
      6#include <stdlib.h>
      7#include <signal.h>
      8#include <linux/perf_event.h>
      9#include <errno.h>
     10#include <stdbool.h>
     11#include <bpf/libbpf.h>
     12#include <bpf/bpf.h>
     13#include "trace_helpers.h"
     14
     15#define PRINT_RAW_ADDR 0
     16
     17/* counts, stackmap */
     18static int map_fd[2];
     19
     20static void print_ksym(__u64 addr)
     21{
     22	struct ksym *sym;
     23
     24	if (!addr)
     25		return;
     26	sym = ksym_search(addr);
     27	if (!sym) {
     28		printf("ksym not found. Is kallsyms loaded?\n");
     29		return;
     30	}
     31
     32	if (PRINT_RAW_ADDR)
     33		printf("%s/%llx;", sym->name, addr);
     34	else
     35		printf("%s;", sym->name);
     36}
     37
     38#define TASK_COMM_LEN 16
     39
     40struct key_t {
     41	char waker[TASK_COMM_LEN];
     42	char target[TASK_COMM_LEN];
     43	__u32 wret;
     44	__u32 tret;
     45};
     46
     47static void print_stack(struct key_t *key, __u64 count)
     48{
     49	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
     50	static bool warned;
     51	int i;
     52
     53	printf("%s;", key->target);
     54	if (bpf_map_lookup_elem(map_fd[1], &key->tret, ip) != 0) {
     55		printf("---;");
     56	} else {
     57		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
     58			print_ksym(ip[i]);
     59	}
     60	printf("-;");
     61	if (bpf_map_lookup_elem(map_fd[1], &key->wret, ip) != 0) {
     62		printf("---;");
     63	} else {
     64		for (i = 0; i < PERF_MAX_STACK_DEPTH; i++)
     65			print_ksym(ip[i]);
     66	}
     67	printf(";%s %lld\n", key->waker, count);
     68
     69	if ((key->tret == -EEXIST || key->wret == -EEXIST) && !warned) {
     70		printf("stackmap collisions seen. Consider increasing size\n");
     71		warned = true;
     72	} else if (((int)(key->tret) < 0 || (int)(key->wret) < 0)) {
     73		printf("err stackid %d %d\n", key->tret, key->wret);
     74	}
     75}
     76
     77static void print_stacks(int fd)
     78{
     79	struct key_t key = {}, next_key;
     80	__u64 value;
     81
     82	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
     83		bpf_map_lookup_elem(fd, &next_key, &value);
     84		print_stack(&next_key, value);
     85		key = next_key;
     86	}
     87}
     88
     89static void int_exit(int sig)
     90{
     91	print_stacks(map_fd[0]);
     92	exit(0);
     93}
     94
     95int main(int argc, char **argv)
     96{
     97	struct bpf_object *obj = NULL;
     98	struct bpf_link *links[2];
     99	struct bpf_program *prog;
    100	int delay = 1, i = 0;
    101	char filename[256];
    102
    103	if (load_kallsyms()) {
    104		printf("failed to process /proc/kallsyms\n");
    105		return 2;
    106	}
    107
    108	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
    109	obj = bpf_object__open_file(filename, NULL);
    110	if (libbpf_get_error(obj)) {
    111		fprintf(stderr, "ERROR: opening BPF object file failed\n");
    112		obj = NULL;
    113		goto cleanup;
    114	}
    115
    116	/* load BPF program */
    117	if (bpf_object__load(obj)) {
    118		fprintf(stderr, "ERROR: loading BPF object file failed\n");
    119		goto cleanup;
    120	}
    121
    122	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
    123	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
    124	if (map_fd[0] < 0 || map_fd[1] < 0) {
    125		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
    126		goto cleanup;
    127	}
    128
    129	signal(SIGINT, int_exit);
    130	signal(SIGTERM, int_exit);
    131
    132	bpf_object__for_each_program(prog, obj) {
    133		links[i] = bpf_program__attach(prog);
    134		if (libbpf_get_error(links[i])) {
    135			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
    136			links[i] = NULL;
    137			goto cleanup;
    138		}
    139		i++;
    140	}
    141
    142	if (argc > 1)
    143		delay = atoi(argv[1]);
    144	sleep(delay);
    145	print_stacks(map_fd[0]);
    146
    147cleanup:
    148	for (i--; i >= 0; i--)
    149		bpf_link__destroy(links[i]);
    150
    151	bpf_object__close(obj);
    152	return 0;
    153}