[Gluster-devel] NetBSD AFR regression

[Justin Clift]

Is there some way to put guards/checks in this bit of code to log
the callers + their arguments somewhere and then stand back to watch
it crash?  And figure it out from there?

Kinda guessing you guys are way past that though...

+ Justin


On 23 Mar 2015, at 17:39, Venky Shankar <yknev.shankar at gmail.com> wrote:
> There are other instances where "iobuf_arena->page_size" is used in
> iobuf.c and there are about a dozen callers for iobuf_size(). There
> needs to be something fishy about the call in the patch you mention to
> trigger the overrun.
> 
> 
> 
> On Mon, Mar 23, 2015 at 10:59 PM, Emmanuel Dreyfus <manu at netbsd.org> wrote:
>> On Mon, Mar 23, 2015 at 01:51:07PM +0100, Emmanuel Dreyfus wrote:
>>> I have ran out of smart ideas, and now I am going to start from older
>>> master and add commits to find the offending one. Any better idea is
>>> welcome.
>> 
>> git bissect points a finger to this change:
>> http://review.gluster.org/9708/
>> 
>> Inthe patch I find this:
>> +                iov.iov_len  = iobuf_size (iobuf)
>> 
>> iobuf_size() contains:
>>        size = iobuf->iobuf_arena->page_size;
>> 
>> and in iobuf_create_stdalloc_arena():
>>        iobuf_arena->page_size = 0x7fffffff;
>> 
>> Am I wrong, or is that a good recipe for an overrun?
>> 
>> 
>> 
>> --
>> Emmanuel Dreyfus
>> manu at netbsd.org
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