Re: Getting sensible information from gdb

From	"Morten W. Petersen" <morphex@gmail.com>
Newsgroups	comp.lang.c
Subject	Re: Getting sensible information from gdb
Date	2015-10-12 03:59 +0200
Organization	Aioe.org NNTP Server
Message-ID	<mvf45e$rb0$1@speranza.aioe.org> (permalink)
References	<mvecqu$b25$1@speranza.aioe.org> <tbjl1bt5723tvgrj1fuoub094fo2bis587@4ax.com> <mvemt2$nbc$1@dont-email.me> <mven9v$2du$1@speranza.aioe.org> <mvf104$hsj$1@dont-email.me>

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On 12.10.2015 03:07, James Kuyper wrote:
> On 10/11/2015 06:20 PM, Morten W. Petersen wrote:
>> On 12.10.2015 00:14, Eric Sosman wrote:
>> [...]
>>>       You've pointed this out to him before, and he asked "Is there a
>>> better alternative?"  I told him of one, and you chipped in with an
>>> even simpler alternative.
>>>
>>>       That was two weeks ago.
>>>
>>>       And he's still using his bloated, unnecessary, silly buffers.
>>>
>>>       I give up.
>>
>> Yes, why don't you take your negative attitude that ruins the fun
>> and go somewhere else?
>
> Tracking down this SIGSEGV has been fun? I didn't get that impression.

Well I learned a bit more, had to get to know gdb better, took my
time and enjoyed it.

As for the buffer and SIGSEGV bit, I learned that variables that
are in conditionals use up space, which is something I didn't know,
and that's cool to know.

But it raises some questions about stack smashing; I remember a
previous discussion about stack smashing, recursion, unpredictable
results and security..

In practice this shows that it is possible to smash the stack and
most of the time that will probably result in a SIGSEGV like it did
now on Linux..  Using gdb was pointless, so I'm wondering what the
approach is to track down these errors except track down allocations
and keeping tabs on stack manually.

-Morten

Thread

Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-11 21:21 +0200
  Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 14:47 -0700
    Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 00:07 +0200
      Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 16:15 -0700
        Re: Getting sensible information from gdb James Kuyper <jameskuyper@verizon.net> - 2015-10-11 21:02 -0400
          Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 18:55 -0700
            Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 04:04 +0200
              Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 19:37 -0700
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 05:16 +0200
            Re: Getting sensible information from gdb James Kuyper <jameskuyper@verizon.net> - 2015-10-12 00:01 -0400
              Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 06:06 +0200
                Re: Getting sensible information from gdb James Kuyper <jameskuyper@verizon.net> - 2015-10-12 00:48 -0400
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 07:08 +0200
          Re: Getting sensible information from gdb Keith Thompson <kst-u@mib.org> - 2015-10-11 18:56 -0700
    Re: Getting sensible information from gdb Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-10-11 18:14 -0400
      Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 00:20 +0200
        Re: Getting sensible information from gdb James Kuyper <jameskuyper@verizon.net> - 2015-10-11 21:07 -0400
          Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 03:59 +0200
            Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 23:21 -0700
              Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 23:32 -0700
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 08:42 +0200
                Re: Getting sensible information from gdb Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-12 17:13 +0100
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 23:50 +0200
                Re: Getting sensible information from gdb Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-13 01:39 +0100
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 03:04 +0200
                Re: Getting sensible information from gdb Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-13 14:13 +0100
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 16:26 +0200
                Re: Getting sensible information from gdb Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-13 17:16 +0100
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-13 18:27 +0200
                Re: Getting sensible information from gdb Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-14 00:17 +0100
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-14 02:26 +0200
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-14 03:59 +0200
                Re: Getting sensible information from gdb Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-14 13:04 +0100
                Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-15 12:48 +0200
              Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 08:41 +0200
      Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 16:18 -0700
        Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 01:22 +0200
          Re: Getting sensible information from gdb Geoff <geoff@invalid.invalid> - 2015-10-11 16:42 -0700
            Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 02:16 +0200
  Getting sensible information from gdb "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-11 18:59 -0700
    Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 04:09 +0200
      Re: Getting sensible information from gdb "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-11 19:28 -0700
        Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 04:59 +0200
          Re: Getting sensible information from gdb "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-10-12 07:10 -0700
            Re: Getting sensible information from gdb Rosario19 <Ros@invalid.invalid> - 2015-10-12 19:41 +0200
  Re: Getting sensible information from gdb Ian Collins <ian-news@hotmail.com> - 2015-10-12 17:59 +1300
    Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 07:36 +0200
      Re: Getting sensible information from gdb Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-10-11 22:59 -0700
        Re: Getting sensible information from gdb "Morten W. Petersen" <morphex@gmail.com> - 2015-10-12 08:27 +0200
          Re: Getting sensible information from gdb Johann Klammer <klammerj@NOSPAM.a1.net> - 2015-10-12 10:55 +0200
          Re: Getting sensible information from gdb Keith Thompson <kst-u@mib.org> - 2015-10-12 08:04 -0700
          Re: Getting sensible information from gdb Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-12 17:35 +0100
      Re: Getting sensible information from gdb Keith Thompson <kst-u@mib.org> - 2015-10-12 08:00 -0700
      Re: Getting sensible information from gdb James Kuyper <jameskuyper@verizon.net> - 2015-10-12 12:25 -0400

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