On Fri, Apr 14, 2023 at 11:39 AM Samuel Thibault
<[email protected]> wrote:
> Sergey Bugaev, le ven. 14 avril 2023 11:29:37 +0300, a ecrit:
> > But secondly, if we are not destroying the user's reply port, but
> > restoring it, then I don't think the "port = MACH_PORT_NULL, arg =
> > stale name" case can happen? So we don't need to handle it?
And just as I sent this, I discovered that there is in fact a place
where we do destroy the port! Ugh!
It's in _hurdsig_abort_rpcs, if the interrupt_operation call fails.
Let's maybe not do that either? We're already making mach_msg seem to
have returned EINTR, which intr-msg knows how to handle.
Currently it's doing this:
case EINTR:
/* Either the process was stopped and continued,
or the server doesn't support interrupt_operation. */
if (ss->intr_port != MACH_PORT_NULL)
/* If this signal was for us and it should interrupt calls, the
signal thread will have cleared SS->intr_port.
Since it's not cleared, the signal was for another thread,
or SA_RESTART is set. Restart the interrupted call. */
{
/* Make sure we have a valid reply port. The one we were using
may have been destroyed by interruption. */
m->header.msgh_local_port = rcv_name = __mig_get_reply_port ();
m->header.msgh_bits = msgh_bits;
option = user_option;
timeout = user_timeout;
goto message;
}
err = EINTR;
/* The EINTR return indicates cancellation, so clear the flag. */
ss->cancel = 0;
break;
but I'm thinking it instead should be doing this:
case EINTR:
/* Either the process was stopped and continued,
or the server doesn't support interrupt_operation. */
if (ss->intr_port != MACH_PORT_NULL)
/* If this signal was for us and it should interrupt calls, the
signal thread will have cleared SS->intr_port.
Since it's not cleared, the signal was for another thread,
or SA_RESTART is set. Restart the interrupted call. */
{
/* Our RPC was interrupted, and the server may have kept the reply
right. Get a fresh reply port from MIG. */
__mig_dealloc_reply_port (rcv_name);
m->header.msgh_local_port = rcv_name = __mig_get_reply_port ();
m->header.msgh_bits = msgh_bits;
option = user_option;
timeout = user_timeout;
goto message;
}
err = EINTR;
/* The EINTR return indicates cancellation, so clear the flag. */
ss->cancel = 0;
break;
...coupled with _hurdsig_abort_rpcs not deallocating our port. wdyt?
Sergey
