Re: GDB 10.1: Backtrace goes into infinite loop

[Simon Marchi <simark@simark.ca>]

On 2020-11-13 5:16 p.m., Paul Smith via Gdb wrote:
> Hi all;
>
> I just upgraded our users from a toolset using GCC 8.1.0, binutils
> 2.30, and GDB 8.2.1, to a new one using GCC 10.2, binutils 2.35.1, and
> GDB 10.1 (on GNU/Linux x86_64).
>
> Now some of my users are running into a problem where they run the "bt"
> command and it shows some subset of the stack frames, then jumps back
> and starts over printing from frame 0, and does this forever until you
> use ^C to stop it.
>
> Apparently this doesn't happen every time, and the number of frames
> that are shown are variable (but usually a smaller number like 2 to 5
> frames).  By "not every time" I mean after a breakpoint sometimes we
> get a good bt and sometimes it recurses, but if it recurses for a given
> bt it will always recurse (that is if you use ^C to stop then "bt"
> again it recurses again).
>
> If we do the same thing with the older GDB (keeping the newer
> compiler/binutils) then we don't see this behavior.
>
> FWIW, the code in question is C++ code and was compiled with -ggdb3 and
> no optimization.
>
> Just wondering if anyone has seen something like this, and/or how to
> try to collect more details.
>

Hi Paul,

When you see the problem happening, you could save a core file (just run
the generate-core-file command).  Then, try to reproduce the problem
using the core file.  If it reproduces, you could upload it to a bug
report.

Simon