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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tracex5_user.c (2304B)

      1// SPDX-License-Identifier: GPL-2.0
      2#include <stdio.h>
      3#include <stdlib.h>
      4#include <unistd.h>
      5#include <linux/filter.h>
      6#include <linux/seccomp.h>
      7#include <sys/prctl.h>
      8#include <bpf/bpf.h>
      9#include <bpf/libbpf.h>
     10#include "trace_helpers.h"
     11
     12#ifdef __mips__
     13#define	MAX_ENTRIES  6000 /* MIPS n64 syscalls start at 5000 */
     14#else
     15#define	MAX_ENTRIES  1024
     16#endif
     17
     18/* install fake seccomp program to enable seccomp code path inside the kernel,
     19 * so that our kprobe attached to seccomp_phase1() can be triggered
     20 */
     21static void install_accept_all_seccomp(void)
     22{
     23	struct sock_filter filter[] = {
     24		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
     25	};
     26	struct sock_fprog prog = {
     27		.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
     28		.filter = filter,
     29	};
     30	if (prctl(PR_SET_SECCOMP, 2, &prog))
     31		perror("prctl");
     32}
     33
     34int main(int ac, char **argv)
     35{
     36	struct bpf_link *link = NULL;
     37	struct bpf_program *prog;
     38	struct bpf_object *obj;
     39	int key, fd, progs_fd;
     40	const char *section;
     41	char filename[256];
     42	FILE *f;
     43
     44	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
     45	obj = bpf_object__open_file(filename, NULL);
     46	if (libbpf_get_error(obj)) {
     47		fprintf(stderr, "ERROR: opening BPF object file failed\n");
     48		return 0;
     49	}
     50
     51	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
     52	if (!prog) {
     53		printf("finding a prog in obj file failed\n");
     54		goto cleanup;
     55	}
     56
     57	/* load BPF program */
     58	if (bpf_object__load(obj)) {
     59		fprintf(stderr, "ERROR: loading BPF object file failed\n");
     60		goto cleanup;
     61	}
     62
     63	link = bpf_program__attach(prog);
     64	if (libbpf_get_error(link)) {
     65		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
     66		link = NULL;
     67		goto cleanup;
     68	}
     69
     70	progs_fd = bpf_object__find_map_fd_by_name(obj, "progs");
     71	if (progs_fd < 0) {
     72		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
     73		goto cleanup;
     74	}
     75
     76	bpf_object__for_each_program(prog, obj) {
     77		section = bpf_program__section_name(prog);
     78		/* register only syscalls to PROG_ARRAY */
     79		if (sscanf(section, "kprobe/%d", &key) != 1)
     80			continue;
     81
     82		fd = bpf_program__fd(prog);
     83		bpf_map_update_elem(progs_fd, &key, &fd, BPF_ANY);
     84	}
     85
     86	install_accept_all_seccomp();
     87
     88	f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
     89	(void) f;
     90
     91	read_trace_pipe();
     92
     93cleanup:
     94	bpf_link__destroy(link);
     95	bpf_object__close(obj);
     96	return 0;
     97}