Re: [RFA/Linux] Ask kernel to kill inferior when GDB terminates

[Pedro Alves <palves at redhat dot com>]

On 12/13/2014 04:27 PM, Joel Brobecker wrote:
>>>>> I could see this making some sense when GDB has spawned the process,
>>>>> but it seems harsh when GDB has attached to the process instead
>>>>> of spawning it?
> [...]
>>> I will adapt my patch when I have a moment.
> 
> Just took a look, and it's not clear to me what the best way to do that
> might me. For native GDB, it'd be fairly easy, if I could just add
> an "attaching_p" parameter to "linux_enable_event_reporting", then
> I could just mask PTRACE_O_EXITKILL out if nonzero. In linux-nat.c,
> it's fairly easy to provide that info. However, things are not so
> clear in the gdbserver case, because linux_enable_event_reporting
> is performed during the event handling conditional on
> child->must_set_ptrace_flags:
> 
>   if (WIFSTOPPED (wstat) && child->must_set_ptrace_flags)
>     {
>       linux_enable_event_reporting (lwpid);
>       child->must_set_ptrace_flags = 0;
>     }
> 
> I think the only clean way to do this would be to add another
> field in struct lwp_info such as "attaching_p" which we would
> set to 1 in the attaching case only.

I think we can get by without adding a new field.  The process_info
structure has the "process->attached" field already.  We could
check that here.  Alternatively, must_set_ptrace_flags could be a
tri-state instead of a boolean, which would be cheaper.

> 
> Does this seem reasonable?
> 
> Thanks,
> 


Thanks,
Pedro Alves