Re: PATCH: proc_do_stop and rpctrace

[Ognyan Kulev]

Marcus Brinkmann wrote:
> That it simply adds the task
> port in proc_child might in fact mean that it uses the user supplied task
> port as you indicate, but I am not sure you meant that.

This is exactly what I meant, but I haven't looked deep enough.  This 
user-supplied task_t is added through proc/mgt.c:add_tasks (called from 
proc/hash.c:task_find, called from proc/mgt.c:S_proc_child).  But 
add_tasks retrieves microkernel's task list and searches for this 
particular task.  So user can't promote his own port as task port to the 
proc server.  So what I said is plain wrong, and just propaganda ;-)

One possible solution is rpctrace not to masquarade system ports, like 
thread ports, and the patch to be reverted.  For example, on each traced 
mach_msg, the list of task's threads can be retrieved.  This will allow 
not masquarading thread ports when they are passed through mach_msg.  It 
will slow the whole tracing, but at least it will circumvent this 
particular problem.

If this solution is good enough, I'm willing to implement it and test it.

Regards
--
Ognyan Kulev <ogi@{fmi.uni-sofia.bg,fsa-bg.org}>
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