Re: catch signal does not appear multi-inferior safe

[Pedro Alves <palves@redhat.com>]

On 07/11/2014 11:56 AM, Chris January wrote:
> Hello,
> 
> It appears to me that the 'catch signal' support in GDB is not
> multi-inferior safe. Combining the 'catch signal' command with the
> 'checkpoint' command, for example, results in an internal error:
> 
> break-catch-sig.c:152: internal-error:
> signal_catchpoint_remove_location: Assertion `signal_catch_counts[iter]
>> 0' failed.
> A problem internal to GDB has been detected,
> further debugging may prove unreliable.
> Quit this debugging session? (y or n)
> 
> see the end of this e-mail for reproducer.
> 
> When checkpointing / catching a fork signal_catchpoint_remove_location
> may be called twice in a row - once for the parent and once for the
> child. 

Signal catchpoint locations aren't really per-process; they're
global.  GDB shouldn't be trying to detach them from the child.
Where is this happening?  Is this from detach_breakpoint ?  That's
odd, since that skips bp_loc_other locations?

> This causes signal_catch_counts to go below 0. I would like some
> advice on how to fix this problem as I am not sure what the correct fix
> is.


-- 
Thanks,
Pedro Alves