r0 = openat(0xffffffffffffff9c, &(0x7f0000000000)='./file1\x00', 0x802c2, 0x0)
r1 = socket$inet_udp(0x2, 0x2, 0x0)
sendfile(r1, r0, 0x0, 0x8000)
preadv(r0, &(0x7f0000000540)=[{&(0x7f0000000000)=""/253, 0x200000fd}], 0x1, 0x10000, 0x0)