Re: kern/43611: kernel-trace (via ktruss) reports wrong parameter/result values

[christos%zoulas.com@localhost (Christos Zoulas)]

The following reply was made to PR kern/43611; it has been noted by GNATS.

From: christos%zoulas.com@localhost (Christos Zoulas)
To: gnats-bugs%NetBSD.org@localhost, kern-bug-people%netbsd.org@localhost, 
        gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost, 
        Wolfgang.Stukenbrock%nagler-company.com@localhost
Cc: 
Subject: Re: kern/43611: kernel-trace (via ktruss) reports wrong 
parameter/result values
Date: Thu, 15 Jul 2010 17:57:18 -0400

 On Jul 15,  8:15pm, dholland-bugs%netbsd.org@localhost (David Holland) wrote:
 -- Subject: Re: kern/43611: kernel-trace (via ktruss) reports wrong parameter
 
 |  Mm, point. Maybe we ought to invent a new kind of tracing for this
 |  purpose (since supervised execution was trendy in research for a while
 |  and it's getting to the point of moving to production...)
 |  
 |  I'm not sure if it makes sense for that to be different from a
 |  debugger interface or not.
 
 We already support PT_SYSCALL, although it might be broken in current.
 |  
 |   >  |  (I'm not particularly clear on exactly what ktruss does that's
 |   >  |  different from running kdump afterwards, but then I've never been
 |   >  |  particularly clear on why ktruss is desirable relative to running
 |   >  |  kdump afterwards, either.)
 |   >  
 |   >  Interactivity; you can watch processes that stop and wait for events
 |   >  and see what they do as you supply the different events.
 |  
 |  Ah. Yeah, I guess that can be useful. The main problem I've always had
 |  with strace and truss and whatnot is that the trace output gets mixed
 |  with the program's output; when I first found ktrace years ago it was
 |  a big step forward.
 
 For that you can use -o fname and tail -f fname in another pty.
 
 christos