r0 = openat$ptmx(0xffffffffffffff9c, &(0x7f0000000040), 0x0, 0x0)
r1 = openat$procfs(0xffffffffffffff9c, &(0x7f0000000540)='/proc/mdstat\x00', 0x0, 0x0)
dup3(r1, r0, 0x0)