Re: gdb handling of Mach exceptions

[Svante Signell]

On Wed, 2016-11-23 at 22:03 -1000, Brent W. Baccala wrote:
> Hi -
> 
> I've been working with gdb on the test programs that Samuel posted to
> test signal preemptors.
> 
> It seems that gdb doesn't reliably intercept the task's exception
> port.  It intercepts it once, when it creates the child process, but
> then assumes that it doesn't change.  Something else, I think
> _hurdsig_init, at hurd/hurdsig.c:1581, then intercepts the task
> exception port again.

I do also see Program received signal ?, Unknown signal  when running
gdb on temacs (from emacs25):
Program received signal ?, Unknown signal.
_hurd_port_get (link=0x102c870, port=0x24) at ../hurd/hurd/port.h:122
bt full see http://paste.debian.net/898594/

FYI: rpctrace temacs makes the box exit with a memory exhaustion
message:
...
task776(pid441)->mach_port_mod_refs (pn{  4} 1 -1) = 0 
task776(pid441)->vm_allocate (139407360 12288 0) = 0x3 ((os/kern) no
space available) 
Child 441 Killed
Coming from error codes for Mach and Unix kernels:
mach/err_kern.sub:"(os/kern) no space available",