r0 = openat$procfs(0xffffffffffffff9c, &(0x7f0000000040)='/proc/key-users\x00', 0x0, 0x0)
preadv2(r0, &(0x7f0000001080)=[{&(0x7f0000000000)=""/4096, 0x1000}], 0x1, 0x3f, 0x0, 0x0)