vmo_get_size - read the current size of a VMO object
#include <magenta/syscalls.h>
mx_status_t mx_vmo_get_size(mx_handle_t handle, uint64_t* size);
vmo_get_size() returns the current size of the VMO.
vmo_get_size() returns MX_OK on success. In the event of failure, a negative error value is returned.
MX_ERR_BAD_HANDLE handle is not a valid handle.
MX_ERR_WRONG_TYPE handle is not a VMO handle.
MX_ERR_INVALID_ARGS size is an invalid pointer or NULL.
vmo_create, vmo_clone, vmo_read, vmo_write, vmo_set_size, vmo_op_range.