r0 = openat$tcp_mem(0xffffffffffffff9c, &(0x7f0000000000)='/proc/sys/net/ipv4/tcp_wmem\x00', 0x1, 0x0)
pwritev(r0, &(0x7f0000002380)=[{&(0x7f0000000040)='C', 0x1}], 0x1, 0x65ff7457, 0x0)