checkptr/race pointer arithmetic result to invalid allocation

[Richiise Nugraha]

Hi, i was testing this code on Go playground and it works just fine, however if i run with `-race` it throws `pointer arithmetic result points to invalid allocation` although it has the same address. What really causes this?, like the address (untouched) still a valid allocation

ptr = 0xc000138008

p = 0xc000138008

base = 0xc000138000

originals = []unsafe.Pointer len: 0, cap: 0, nil

https://go.dev/play/p/RcvaWHJ8dMB

(or https://gist.github.com/ii64/d9753a03f0fad8172729e044943a35e5)

Thanks

[Ian Lance Taylor]

Your code is breaking the unsafe.Pointer rules documented at
https://pkg.go.dev/unsafe#Pointer.

Ian