Re: [RFA/commit 3/3] fix internal_error during fork event handling.

[Pedro Alves <palves at redhat dot com>]

On 06/21/2012 10:18 PM, Joel Brobecker wrote:

> Here is what happens:
>   1. GDB receives a "fork" event;
>   2. handle_inferior_event calls detach_breakpoints for the child process;
>   3. detach_breakpoints calls ia64's gdbarch remove_breakpoint hook,
>      which needs to read an entire instruction slot in order to remove
>      a breakpoint instruction from memory;
>   4. To read inferior memory, the ia64-hpux code needs to know where
>      that memory is located relative to the bsp..bspstore area,
>      and thus needs to read the value of those registers;
>   5. To get the value of those registers, ia64_hpux_xfer_memory current
>      uses the current regcache.
> 
> The problem is taht at the time we are trying to remove the breakpoints

Typo "that".

> from the child, the child process is not part of the list of inferiors
> really known to GDB (it has not been added to inferior_list), and there
> is therefore no regcache for that process.  This is what triggers the
> internal error.

The text for the commit log should be updated too (if that's what
this is).  I suggest replacing

  and there is therefore no regcache for that process

with something like

  and so trying to create a regcache for it internal errors when creating an
  address space for the regcache (as the address space is ultimately fetched
  from the inferior.

Thanks.

-- 
Pedro Alves