Several small questions in utrace

[Roland McGrath]

> Review the rawhide kernel-doc. Found there are several small questions 
> those may be updated next round.

Thanks!

> 1. Redundant "returns" in Using utrace_barrier
> Otherwise returns it waits until the thread is definitely not in the
> midst of a callback to this engine and then returns zero

It so happens I had just noticed and fixed this the same evening.

> 2. Incomprehensive description in syscall_set_arguments
> Changes n arguments to the system call starting with the i'th argument. 
> n'th argument to val.
> 
> 3. Typo "report_report" in tracehook_report_clone (same in linus tree)
> otherwise it might have died and been released by the time 
> tracehook_report_report_clone_complete is called.

These two are in code that is now upstream.  So these can now be dealt with
via the normal upstream kernel patch procedures.  There's no longer any
need to do them separately here.  I'm sending a patch upstream now, and
will CC you.

> And in compiling utrace-patched kernel, there is warning of gcc 3.x
> utrace.h:177, incomplete type.

I moved the decls around.  Please let me know how the current patch works.


Thanks,
Roland