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Date: Fri, 3 Aug 2018 14:33:51 -0700
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Subject: Re: [PATCH] Verify memory sizes on 32 bit systems.
From: Lucas De Marchi <lucas.de.marchi@gmail.com>
To: Tobias Stoeckmann <tobias@stoeckmann.org>
Cc: linux-modules <linux-modules@vger.kernel.org>
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On Fri, Aug 3, 2018 at 2:10 PM Tobias Stoeckmann <tobias@stoeckmann.org> wrote:
>
> On Fri, Aug 03, 2018 at 02:07:34PM -0700, Lucas De Marchi wrote:
> > > +       if ((uintmax_t)st.st_size > (uintmax_t)SIZE_MAX)
> >
> > why casting?
>
> Without casting, a warning could be triggered on 64 bit systems,
> because on these systems a signed 64 bit int (off_t) is compared
> with an unsigned 64 bit int (size_t) which could never be larger.
>
> Casting it to uintmax_t, which is at least 64 bits in size,
> silences this error.

so you are casting the *sign* away, ok. But casting only st.st_size
should suffice.

Lucas De Marchi

>
> No technical reason beyond that.
>
>
> Tobias



-- 
Lucas De Marchi