* catch signal does not appear multi-inferior safe
@ 2014-07-11 10:56 Chris January
2014-08-19 15:37 ` Pedro Alves
0 siblings, 1 reply; 3+ messages in thread
From: Chris January @ 2014-07-11 10:56 UTC (permalink / raw)
To: gdb
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. 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.
Regards,
Chris January - VP Engineering - Allinea Software Ltd.
The problem can be reproduced using the following GDB commands - run GDB
from gdb/testsuite/gdb.base:
file checkpoint
break main
run
catch signal SIGSEGV
break 48
continue
checkpoint
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: catch signal does not appear multi-inferior safe
2014-07-11 10:56 catch signal does not appear multi-inferior safe Chris January
@ 2014-08-19 15:37 ` Pedro Alves
2014-08-28 10:58 ` Chris January
0 siblings, 1 reply; 3+ messages in thread
From: Pedro Alves @ 2014-08-19 15:37 UTC (permalink / raw)
To: Chris January, gdb
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
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: catch signal does not appear multi-inferior safe
2014-08-19 15:37 ` Pedro Alves
@ 2014-08-28 10:58 ` Chris January
0 siblings, 0 replies; 3+ messages in thread
From: Chris January @ 2014-08-28 10:58 UTC (permalink / raw)
To: Pedro Alves; +Cc: gdb
Hello Pedro,
On Tue, 2014-08-19 at 16:37 +0100, Pedro Alves wrote:
> On 07/11/2014 11:56 AM, Chris January wrote:
> > 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?
You are right. I was testing with an old version of GDB (7.6.2). It is
fixed in recent versions by this commit:
commit bd9673a4ded96ea5c108601501c8e59003ea1be6
Author: Philippe Waroquiers <philippe@sourceware.org>
Date: Tue May 21 18:47:05 2013 +0000
Fix internal error caused by interaction between catch signal and
fork
Sorry for the noise!
Regards,
Chris
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-08-28 10:58 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-07-11 10:56 catch signal does not appear multi-inferior safe Chris January
2014-08-19 15:37 ` Pedro Alves
2014-08-28 10:58 ` Chris January
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).