Re: [PATCH v3 1/3] selftests/mm/write_to_hugetlbfs: parse -s as size_t

[David Laight]

On Tue, 23 Dec 2025 17:29:38 +0800
Li Wang <liwang@xxxxxxxxxx> wrote:

> David Laight <david.laight.linux@xxxxxxxxx> wrote:
> 

> > What was wrong with atoi() ?  
> 
> As the patch summary described, write_to_hugetlbfs previously parsed -s via
> atoi() into an int, which can overflow and print negative sizes. This
> problem was
> found on our kernel-64k platform and
> 
>  #./charge_reserved_hugetlb.sh -cgroup-v2
>  # -----------------------------------------
>  ...
>  # nr hugepages = 10
>  # writing cgroup limit: 5368709120
>  # writing reseravation limit: 5368709120
>  ...
>  # Writing to this path: /mnt/huge/test
>  # Writing this size: -1610612736        <--------

So the problem was that atoi() doesn't let you specify valid values
over 2GB.
That isn't how I read the patch summary.
It read as though you were worried about detecting invalid input.

	David