Re: [PATCH 09/30] mtd: Don't cast kmalloc() return value in drivers/mtd/maps/pmcmsp-flash.c

From: Jesper Juhl
Date: Sun Aug 26 2007 - 18:10:52 EST


On 26/08/07, Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx> wrote:
>
> On Aug 26 2007 15:28, Denys Vlasenko wrote:
> >> >
> >> > What exactely would using kcalloc() over kzalloc() here buy us?
> >>
> >> technically, nothing.
> >
> >The idea of calloc is that it can check for underflow in parameter.
>
> Actually, overflow.
>
> calloc(0xFFFF0000, 0x1000) => will return NULL
> malloc(0xFFFF0000 * 0x1000) => silent 32 bit multiplication/truncation,
> will allocate less than requested.
>
> >calloc(-1, 10000000) => easy to detect
> >malloc(-1 * 10000000) => malloc(-10000000) => not so trivial
>
Ok, that makes a bit of sense. Thank you.


--
Jesper Juhl <jesper.juhl@xxxxxxxxx>
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