Re: [Qemu-devel] [PATCH] use qemu_malloc and friends consistently

[Kevin Wolf <kwolf@redhat.com>]

jcd@tribudubois.net schrieb:
> ----- "Kevin Wolf" <kwolf@redhat.com> a écrit :
> 
>> jcd@tribudubois.net schrieb:
>>> Kevin,
>>>
>>> I certainly understand your goal ... 
>>>
>>> Anyway, I will update my patche and resubmit.
>>>
>>> BTW it has to be noted that most of the time the return value of
>> malloc/qemu_malloc is not checked which can also prove problematic
>> whatever the qemu_malloc/malloc behavior is.
>>
>> It doesn't need to be checked, qemu_malloc never returns if it fails.
>> If
>> malloc(0) returns NULL (on success!) checking it is even wrong in
>> places
>> where this can happen.
> 
> I don't necessarily speak about the malloc(0) case.
> 
> Up to now the qemu_io code (for example) was using malloc() without checking for the returned value. If allocation fails, I believe it would be quite wrong to pass the returned (NULL) pointer to memcpy/memset/memcmp whatever platform you are considering ...
> 
> So it seems to me you definitively need a way to dicriminate between the value returned on succesfull malloc(0) and the value returned on a failed malloc(1000).

I should not have mentioned the malloc(0) in this mail, it only adds to
the confusion.

What I wanted to say is that a failed qemu_malloc doesn't return
anything because it aborts (this code is in oom_check). So the caller
needs not and even cannot check for failure.

Kevin