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Date: Sat, 06 Aug 2011 06:40:12 +0200
From: Luka Marčetić <paxcoder@...il.com>
To: musl@...ts.openwall.com
Subject: Re: New daily reports - debugging alloc.c et al

On 08/05/2011 02:02 AM, Luka Marčetić wrote:
> I tried to do the above, but got pretty stuck, so I'll have to finish 
> it tomorrow unfortunately.
> Accordingly, priorities are:
>     *finish pthread_eintr.c
>     *decide about the generator, take another task
> Attached is the diff form of the above report.
>
> Talk to you soon.
> Luka.

Hello
The day started with Szabolcs suggesting I use valgrind to debug 
alloc.c. A very good idea, one which changed my priorities. Rich 
explained to me how memory management works behind the scenes (an 
explanation I very much needed), and suggested an mmap-based method to 
employ to find bugs. I've been changing the prog until now (6am here), 
but the method of allocation that I've been recommended either fails to 
fulfill its promise, or I'm blind to my own bug.
Here's a minimal test case:
http://paste.debian.net/125242/
A quick explanation: Alloc.c needs to squat most of process' virtual 
memory. I employ a kind of binary search to find the greatest size that 
can be allocated, but then it turns out, mmap and malloc are able to 
continue allocating memory still. Not sure why.

Priorities:
* finish this test collection for good (need your replies for that)
* work on pthread_eintr.c

That's it for today.
Luka

P.S. Lost diff history, attached is repo vs local /tests diff, come 
commits not included

View attachment "to-report" of type "text/plain" (529 bytes)

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