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

From: Jan Engelhardt
Date: Sun Aug 26 2007 - 10:37:53 EST



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


Jan
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