Re: [Xen-devel] [PATCH 1/8] libelf: loop safety: Introduce elf_iter_ok and elf_strcmp_safe

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 12.12.16 at 17:56, <ian.jackson@xxxxxxxxxxxxx> wrote:
> Jan Beulich writes ("Re: [PATCH 1/8] libelf: loop safety: Introduce 
> elf_iter_ok and elf_strcmp_safe"):
>> Well, I have to confess that I've read the above as max() when
>> in fact it is min().
> 
> Sadly we can't use min() and max() here it seems.

Sure, I understand that.

>> On 12.12.16 at 17:00, <ian.jackson@xxxxxxxxxxxxx> wrote:
>> > The max_size_for_deacc part is necessary because otherwise the
>> > calculation "size * ELF_MAX_ITERATION_FACTOR" might overflow.  It
>> > seems unreasonable to simply allow that overflow to occur.  But if it
>> > is causing confusion we could do that.  The result would be a low
>> > value for iteration_deaccumulator.
>> 
>> Considering that overflow here will actually result in a comparably
>> smaller upper limit, I think this may help overall readability. But with
>> the above I won't insist on this in any way.
> 
> I have replaced the limit with a comment.  Now I have:
> 
>     elf->iteration_deaccumulator =
>         1024*1024 + size * ELF_MAX_ITERATION_FACTOR;        
>         /* overflow (from very big size, probably rejected earlier)
>          * would just lead to small limit, which is safe */

Thanks. May I ask that you then also use proper hypervisor
style for that comment?

Jan


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