r0 = openat$tcp_mem(0xffffffffffffff9c, &(0x7f00000004c0)='/proc/sys/net/ipv4/tcp_rmem\x00', 0x1, 0x0)
writev(r0, &(0x7f0000000740)=[{&(0x7f00000005c0)="34e0", 0x2}], 0x1)