r0 = openat$procfs(0xffffffffffffff9c, &(0x7f00000000c0)='/proc/key-users\x00', 0x0, 0x0)
preadv2(r0, &(0x7f0000000080)=[{&(0x7f0000000000)=""/2, 0x2}], 0x1, 0x2, 0x0, 0x0)