🚀 go-pugleaf

In article <77747@tut.cis.ohio-state.edu>, philk@tictoc.cis.ohio-state.edu (Phillip E Krueger) writes:
> Under Mach 2.5, what task does execve belong to (i.e. what task and
> thread are considered current when execve is executed)?  The mach task?
> The user task whose thread called it?
> 
> Thanks,
>   -- Phil

Mach 2.5 supports Unix in-kernel.  This means that the Mach abstractions 
_and_ the Unix abstractions co-exist, and each one tries very hard not to
interfere with the other.

The Unix semantics is provided by equating

	Unix-process ==  This-thread + Its-task

which in the case of execve means:
	1) terminate all other threads in the same task of the invoking
	   thread
	2) reshape the task's address space as described in the executable
	   image (text+data+implicit-stack)
	3) restart this thread at the PC defined in the executable image.

Additional clarifications:
1- the relation thread->task never changes once established (at thread
   creation time)
2- Unix primitives never take Mach entities as parameters

sandro-