r0 = openat$procfs(0xffffffffffffff9c, &(0x7f00000003c0)='/proc/key-users\x00', 0x0, 0x0)
preadv(r0, &(0x7f00000004c0)=[{&(0x7f0000000000)=""/57, 0x39}], 0x1, 0x200, 0x0)