Re: How to use backtrace() safely in signal handler.

[Florian Weimer <fweimer at redhat dot com>]

* Adhemerval Zanella:

> On 09/12/2019 13:17, Florian Weimer wrote:
>> * Adhemerval Zanella:
>> 
>>>> What is the usual "out-of-process" practice?
>>>>   /proc/sys/kernel/core_pattern + abrt kind of configuration (take
>>>> rhel/centos distribution as an example)?
>>>
>>> The abrt afaik just setup and handle the generated core file by
>>> configuring the system required parameters. You will still need
>>> a tool to read and process the core file, gdb for instance.
>> 
>> No, both ABRT and systemd contain tools to performan basic analysis,
>> such as capturing symbolic backtraces.  without every writing the
>> coredump to disk (which can be very large).
>
> Interesting, I wasn't aware of that. How does it accomplish it? Linking
> with libelf or something related and analysing the code itself?

Yes, I think the backtraces come from <https://github.com/abrt/satyr>.
The kernel enables this because you can mmap stdin with the coredump
in the coredump handler (or you can poke at /proc).

Thanks,
Florian