[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
Re: kern/43611: kernel-trace (via ktruss) reports wrong parameter/result values
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,
Subject: Re: kern/43611: kernel-trace (via ktruss) reports wrong
Date: Wed, 14 Jul 2010 08:36:07 -0400
On Jul 14, 1:50am, dholland-bugs%netbsd.org@localhost (David Holland) wrote:
-- Subject: Re: kern/43611: kernel-trace (via ktruss) reports wrong parameter
| On Tue, Jul 13, 2010 at 05:40:04PM +0000, David Laight wrote:
| > ktruss probably should be rewritten to use system call entry/exit
| > breakpoints and then userspace controlled reads of the traced programs
| > memory (which is how truss works on SYSV).
| Using ptrace for this purpose is not desirable because it monkeys with
| the parent/child process relationships and tends to break things,
| particularly shell scripts.
It is desirable because it stops the process and lets you examine the
syscall arguments in detail.
| (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.
Main Index |
Thread Index |