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#define _GNU_SOURCE
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include "../../memcheck.h"
static void
assert_expected (int fd, int expected_seals)
{
int current_seals = fcntl (fd, F_GET_SEALS);
assert (current_seals == expected_seals);
}
static void
add_seal (int fd, int *expected_seals, int new_seal)
{
int r = fcntl (fd, F_ADD_SEALS, new_seal);
assert (r == 0);
*expected_seals |= new_seal;
// Make sure we get the result we expected.
assert_expected (fd, *expected_seals);
}
static void
add_seal_expect_fail (int fd, int new_seal, int expected_errno)
{
int r = fcntl (fd, F_ADD_SEALS, new_seal);
assert (r == -1 && errno == expected_errno);
}
int
main (void)
{
int expected_seals = 0;
int fd;
// Try with an fd that doesn't support sealing.
fd = memfd_create ("xyz", 0);
if (fd < 0)
{
// Not supported, nothing to test...
return 1;
}
assert_expected (fd, F_SEAL_SEAL);
add_seal_expect_fail (fd, F_SEAL_WRITE, EPERM);
assert_expected (fd, F_SEAL_SEAL); // ...should still be unset after failed attempt
close (fd);
// Now, try the successful case.
fd = memfd_create ("xyz", MFD_ALLOW_SEALING);
add_seal (fd, &expected_seals, F_SEAL_SHRINK);
add_seal (fd, &expected_seals, F_SEAL_GROW);
// Now prevent more sealing.
add_seal (fd, &expected_seals, F_SEAL_SEAL);
// And make sure that it indeed fails.
add_seal_expect_fail (fd, F_SEAL_WRITE, EPERM);
assert_expected (fd, expected_seals);
close (fd);
// Test the only memory failure possible: passing an undefined argument to F_ADD_SEALS
int undefined_seal = 0;
VALGRIND_MAKE_MEM_UNDEFINED(&undefined_seal, sizeof undefined_seal);
fcntl (-1, F_ADD_SEALS, undefined_seal);
return 0;
}
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