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Re: [mi] watchpoint-scope exec async command
> > breakpoint.c:5761 is where the related_breakpoint is allocated
> > breakpoint.c:6721 is where the related_breakpoint is deleted
> > breakpoint.c:1022 is where the problem occurs (just the next sucker to
> > read/write the free'd related_breakpoint field)
> >
> > So, at breakpoint.c:5761 I do,
> > (tgdb) p b
> > $1 = (struct breakpoint *) 0x83b4878
> > (tgdb) p b->related_breakpoint
> > $2 = (struct breakpoint *) 0x83b49d0
> >
> > Then at breakpoint.c:6721, I print the breakpoint to be deleted
> > (tgdb) p bpt
> > $3 = (struct breakpoint *) 0x83b49d0
> >
> > This is the related_breakpoint!
> >
> > at the end of breakpoint_delete I do
> > (tgdb) p breakpoint_chain->next->next->next->next->next->next
> > $30 = (struct breakpoint *) 0x83b4878
> >
> > (tgdb) p breakpoint_chain->next->next->next->next->next->next->related_breakpoint
> > $32 = (struct breakpoint *) 0x83b49d0
>
> So far, actually, so good - but is this still true when
> breakpoint_auto_delete returns? Why isn't the other one deleted too?
> What's its "disposition" at this point?
Yes,
(tgdb) p breakpoint_chain->next->next->next->next->next->next
$47 = (struct breakpoint *) 0x83b4878
(tgdb) p breakpoint_chain->next->next->next->next->next->next->disposition
$51 = disp_donttouch
(tgdb) p breakpoint_chain->next->next->next->next->next->next->related_breakpoint
$48 = (struct breakpoint *) 0x83b49d0
(tgdb) p breakpoint_chain->next->next->next->next->next->next->related_breakpoint->disposition
$49 = disp_del
I don't know why this seems OK to you. I must be missing something.
breakpoint_chain->next->next->next->next->next->next->related_breakpoint
was a pointer to a breakpoint that was deleted. Thus, the pointer is
invalid. The reference to the deleted breakpoint (related_breakpoint
field) must be set to NULL somehow.
It seems that whenever a breakpoint is deleted, all other
breakpoints related_breakpoint field needs to be checked, to see if they
pointed to the data that was just deleted.
Please look at the comments at breakpoint.c:6723 and breakpoint.c:1325.
Thanks,
Bob Rossi