[OSRM-talk] Segfault with 5.4.0 osrm-extract and foot.lua

Frederik Ramm frederik at remote.org
Mon Oct 10 08:46:36 UTC 2016


On 10/07/2016 09:43 AM, Frederik Ramm wrote:
> I have finished bisecting the commits and ended up with
> 2b466b2fb29c416149b4d881c151349218a63e1e as the first bad commit -
> everything before that works, everything after that segfaults. I'll have
> a closer look.

I'm afraid I couldn't pinpoint the problem. I'm pretty sure there is
*some* kind of memory corruption but exactly when and where it hits
seems to be dependent on the STXXL configuration among other things.

To summarize:

* The problem is always reported as "double free or corruption
(fasttop)" and leads to a segfault in osrm-extract on Ubuntu 16.04.

* The problem affects all OSRM versions from commit
2b466b2fb29c416149b4d881c151349218a63e1e on (this means v5.2.7 is the
last-known-good release). I read through that commit and couldn't
immediately see anything that looks broken.

* The problem does not occur with the "car" profile but it does occur
with the "bicycle" and "foot" profiles.

* The problem does not occur with data extracts smaller than ~ 2 GB but
it does occur with larger ones. Sadly that made it impossible for me to
find a very small input file that would provoke the crash, and any
"valgrind" debugging was out of the question.

I'll leave it at that and work with 5.2.7 which is good enough for my
use case. Given that you say all profiles work for you in 5.4, it might
be a funny edge case on Ubuntu or even on this particular machine I was
running it on. Time permitting I might re-run on a different machine
some time later.


Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"

More information about the OSRM-talk mailing list