path: root/tools/testing/selftests/memfd/memfd_test.c

#define _GNU_SOURCE
#define __EXPORTED_HEADERS__

#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <linux/falloc.h>
#include <linux/fcntl.h>
#include <linux/memfd.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <unistd.h>

#define MFD_DEF_SIZE 8192
#define STACK_SIZE 65535

static int sys_memfd_create(const char *name,
			    unsigned int flags)
{
	return syscall(__NR_memfd_create, name, flags);
}

static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags)
{
	int r, fd;

	fd = sys_memfd_create(name, flags);
	if (fd < 0) {
		printf("memfd_create(\"%s\", %u) failed: %m\n",
		       name, flags);
		abort();
	}

	r = ftruncate(fd, sz);
	if (r < 0) {
		printf("ftruncate(%llu) failed: %m\n", (unsigned long long)sz);
		abort();
	}

	return fd;
}

static void mfd_fail_new(const char *name, unsigned int flags)
{
	int r;

	r = sys_memfd_create(name, flags);
	if (r >= 0) {
		printf("memfd_create(\"%s\", %u) succeeded, but failure expected\n",
		       name, flags);
		close(r);
		abort();
	}
}

static unsigned int mfd_assert_get_seals(int fd)
{
	int r;

	r = fcntl(fd, F_GET_SEALS);
	if (r < 0) {
		printf("GET_SEALS(%d) failed: %m\n", fd);
		abort();
	}

	return (unsigned int)r;
}

static void mfd_assert_has_seals(int fd, unsigned int seals)
{
	unsigned int s;

	s = mfd_assert_get_seals(fd);
	if (s != seals) {
		printf("%u != %u = GET_SEALS(%d)\n", seals, s, fd);
		abort();
	}
}

static void mfd_assert_add_seals(int fd, unsigned int seals)
{
	int r;
	unsigned int s;

	s = mfd_assert_get_seals(fd);
	r = fcntl(fd, F_ADD_SEALS, seals);
	if (r < 0) {
		printf("ADD_SEALS(%d, %u -> %u) failed: %m\n", fd, s, seals);
		abort();
	}
}

static void mfd_fail_add_seals(int fd, unsigned int seals)
{
	int r;
	unsigned int s;

	r = fcntl(fd, F_GET_SEALS);
	if (r < 0)
		s = 0;
	else
		s = (unsigned int)r;

	r = fcntl(fd, F_ADD_SEALS, seals);
	if (r >= 0) {
		printf("ADD_SEALS(%d, %u -> %u) didn't fail as expected\n",
				fd, s, seals);
		abort();
	}
}

static void mfd_assert_size(int fd, size_t size)
{
	struct stat st;
	int r;

	r = fstat(fd, &st);
	if (r < 0) {
		printf("fstat(%d) failed: %m\n", fd);
		abort();
	} else if (st.st_size != size) {
		printf("wrong file size %lld, but expected %lld\n",
		       (long long)st.st_size, (long long)size);
		abort();
	}
}

static int mfd_assert_dup(int fd)
{
	int r;

	r = dup(fd);
	if (r < 0) {
		printf("dup(%d) failed: %m\n", fd);
		abort();
	}

	return r;
}

static void *mfd_assert_mmap_shared(int fd)
{
	void *p;

	p = mmap(NULL,
		 MFD_DEF_SIZE,
		 PROT_READ | PROT_WRITE,
		 MAP_SHARED,
		 fd,
		 0);
	if (p == MAP_FAILED) {
		printf("mmap() failed: %m\n");
		abort();
	}

	return p;
}

static void *mfd_assert_mmap_private(int fd)
{
	void *p;

	p = mmap(NULL,
		 MFD_DEF_SIZE,
		 PROT_READ,
		 MAP_PRIVATE,
		 fd,
		 0);
	if (p == MAP_FAILED) {
		printf("mmap() failed: %m\n");
		abort();
	}

	return p;
}

static int mfd_assert_open(int fd, int flags, mode_t mode)
{
	char buf[512];
	int r;

	sprintf(buf, "/proc/self/fd/%d", fd);
	r = open(buf, flags, mode);
	if (r < 0) {
		printf("open(%s) failed: %m\n", buf);
		abort();
	}

	return r;
}

static void mfd_fail_open(int fd, int flags, mode_t mode)
{
	char buf[512];
	int r;

	sprintf(buf, "/proc/self/fd/%d", fd);
	r = open(buf, flags, mode);
	if (r >= 0) {
		printf("open(%s) didn't fail as expected\n", buf);
		abort();
	}
}

static void mfd_assert_read(int fd)
{
	char buf[16];
	void *p;
	ssize_t l;

	l = read(fd, buf, sizeof(buf));
	if (l != sizeof(buf)) {
		printf("read() failed: %m\n");
		abort();
	}

	/* verify PROT_READ *is* allowed */
	p = mmap(NULL,
		 MFD_DEF_SIZE,
		 PROT_READ,
		 MAP_PRIVATE,
		 fd,
		 0);
	if (p == MAP_FAILED) {
		printf("mmap() failed: %m\n");
		abort();
	}
	munmap(p, MFD_DEF_SIZE);

	/* verify MAP_PRIVATE is *always* allowed (even writable) */
	p = mmap(NULL,
		 MFD_DEF_SIZE,
		 PROT_READ | PROT_WRITE,
		 MAP_PRIVATE,
		 fd,
		 0);
	if (p == MAP_FAILED) {
		printf("mmap() failed: %m\n");
		abort();
	}
	munmap(p, MFD_DEF_SIZE);
}

static void mfd_assert_write(