Утилита для изменения аптайма

Работает без использования машины времени.

/*
 * $ gcc hack.c -o hack
 * # ./hack <смещение в секундах>
 * например # ./hack 86400 добавит одни сутки
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>

int main(int argc, char *argv[]) {
	if(argc < 2) {
		printf("Usage: %s <change in seconds>\n", argv[0]);
		return 1;
	}
	int off = atoi(argv[1]);
	size_t address;
	char line[256];
	FILE* ksyms = fopen("/proc/kallsyms", "r");
	while(fgets(line, sizeof(line), ksyms))
		if(strstr(line, " wall_to_monotonic")) {
			sscanf(line, "%zx", &address);
			break;
		}
	
	fclose(ksyms);
	if(!address) {
		fprintf(stderr, "[-] wall_to_monotonic not found\n");
		exit(1);
	}

	printf("[+] wall_to_monotonic: %lx\n", address);

	int hndl = open("/dev/kmem", O_RDWR);
	if(hndl == -1) {
		perror("[-] open");
		return 1;
	}
	
	printf("[+] open\n");

	void *ptr = mmap(NULL, 0x2000, PROT_READ | PROT_WRITE, MAP_SHARED, hndl, address & ~0x0FFF);
	if(ptr == MAP_FAILED) {
		perror("[-] mmap");
		return 1;
	}

	printf("[+] mmap\n");

	struct timespec *ts = (ptr + (address & 0xFFF));

	ts->tv_sec += off;

	printf("[+] patch\n");
	munmap(ptr, 0x2000);
	close(hndl);

}