r0 = memfd_create(&(0x7f0000000000)='\x00', 0x0)
fallocate(r0, 0x0, 0x0, 0x20)
preadv(r0, &(0x7f0000000400)=[{&(0x7f0000000040)=""/13, 0xd}], 0x1, 0x0, 0x0)