From: Jan Kiszka <jan.kiszka@siemens.com>
To: Kieran Bingham <kieran.bingham@linaro.org>,
Peter Griffin <peter.griffin@linaro.org>,
gdb@sourceware.org
Subject: Re: gdb.Value returning a string of length 1 (linux lx-version bug)
Date: Tue, 22 Mar 2016 17:57:00 -0000 [thread overview]
Message-ID: <56F18761.8030901@siemens.com> (raw)
In-Reply-To: <56F186C1.1080803@linaro.org>
Hi Kieran,
On 2016-03-22 18:54, Kieran Bingham wrote:
> Hi Jan,
>
> Me and Pete have just been looking into the gdb.Value object bug where
> the lx-version command returns a string of length 1.
>
> As I recall at FOSDEM, you were also hitting the bug.
> Out of interest, what compiler version are you using?
gcc (SUSE Linux) 4.8.3 20140627 [gcc-4_8-branch revision 212064]
>
> We've made some head way, but we are suspicious that compiler versions
> may affect the issue ! :(
>
> The crux of the issue, is that the valpy_string() calls c_get_string()
> which in turn calls get_discrete_bounds().
>
> On my broken version, get_discrete_bounds, is setting both lowp, and
> highp to 0x0; where as on Peters working version, his highp gets set
> correctly. (there is a +1 added later which results in the string
> producing a strlen of 1)
>
> I'm running gcc 5.2.1-22ubuntu2, whereas Pete is running gcc 4.8.4.
>
> Pete's version of his compiled binutils-gdb always seems to function
> correctly, where as I hit the bug - *occasionally*
>
> Of course, since I have compiled with -g3 -O0 -fsanitize=undefined I
> can't reproduce the issue, and now even removing the optimise levels I
> haven't been able to reproduce.
>
> We have a Heisenbug :(
Maybe wait for someone seeing this more reproducibly? :-/
Jan
>
> Has anyone else on the GDB Mailinglist experienced any intermittent
> errors with gdb.Value strings from python?
> --
> Kieran
>
--
Siemens AG, Corporate Technology, CT RDA ITP SES-DE
Corporate Competence Center Embedded Linux
next prev parent reply other threads:[~2016-03-22 17:57 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-22 17:54 Kieran Bingham
2016-03-22 17:57 ` Jan Kiszka [this message]
2016-03-23 8:50 ` Kieran Bingham
2016-03-23 13:26 ` Kieran Bingham
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