[U-Boot] [PATCH] Prevent malloc with size 0

Graeme Russ graeme.russ at gmail.com
Mon Apr 2 05:43:08 CEST 2012


Hi Marek,

On Mon, Apr 2, 2012 at 1:36 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
> Dear Mike Frysinger,
>
>> On Sunday 01 April 2012 20:25:44 Graeme Russ wrote:
>> > b) The code calling malloc(0) is making a perfectly legitimate assumption
>> >
>> >    based on how glibc handles malloc(0)
>>
>> not really.  POSIX says malloc(0) is implementation defined (so it may
>> return a unique address, or it may return NULL).  no userspace code
>> assuming malloc(0) will return non-NULL is correct.
>
> Which is your implementation-defined ;-) But I have to agree with this one. So
> my vote is for returning NULL.

Also, no userspace code assuming malloc(0) will return NULL is correct

Point being, no matter which implementation is chosen, it is up to the
caller to not assume that the choice that was made was, in fact, the
choice that was made.

I.e. the behaviour of malloc(0) should be able to be changed on a whim
with no side-effects

So I think I should change my vote to returning NULL for one reason and
one reason only - It is faster during run-time

Regards,

Graeme


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