#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>

#ifndef AT_FDCWD
#define AT_FDCWD -100
#endif

#if defined(__i386__)
#define __NR_revokeat	324
#else
#error unsupported arch
#endif

int revokeat(int dfd, const char *path)
{
	return syscall(__NR_revokeat, dfd, path);
}

void catch_bus(int sig_num)
{
	printf("Test OK\n");
	exit(1);
}

void catch_segv(int sig_num)
{
	printf("Failed: caught SIGSEGV\n");
	exit(1);
}

static void panic(const char *s)
{
	perror(s);
	exit(1);
}

int main(int argc, char *argv[])
{
	int fd, err, i;
	char *p;

	signal(SIGBUS, catch_bus);
	signal(SIGSEGV, catch_segv);

	fd = open(argv[1], O_RDWR);
	if (fd < 0)
		panic("open");

	p = mmap(0, getpagesize(), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
	if (p == MAP_FAILED)
		panic("mmap");

	err = revokeat(AT_FDCWD, argv[1]);
	if (err)
		panic("revokeat");

	for (i = 0; i < getpagesize(); i++)
		p[i] = 0xff;

	printf("Failed: allowed access to revoked shared mapping\n");
	exit(1);
}