From: Andreas Dilger <adilger@turbolinux.com>
To: "Collins, Tom" <Tom.Collins@surgient.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Dynamically altering code segments
Date: Tue, 27 Feb 2001 10:05:37 -0700 (MST) [thread overview]
Message-ID: <200102271705.f1RH5bB27105@webber.adilger.net> (raw)
In-Reply-To: <A490B2C9C629944E85CE1F394138AF957FC3E1@bignorse.SURGIENT.COM> from "Collins, Tom" at "Feb 27, 2001 10:43:02 am"
Tom Collins writes:
> I am wanting to dynamically modify the kernel in specific places to
> implement a custom kernel trace mechanism. The general idea is that,
> when the "trace" is off, there are NOP instruction sequences at various
> places in the kernel. When the "trace" is turned on, those same NOPs
> are replaced by JMPs to code that implements the trace (such as logging
> events, using the MSR and PMC's etc..).
>
> This was a trick that was done in my old days of OS/2 performance tools
> developement to get trace information from the running kernel.
>
> Is it possible to do the same thing in Linux?
See IBM "dprobes" project. It is basically what you are describing
(AFAIK). It makes sense, because a lot of the OS/2 folks are now working
on Linux.
Cheers, Andreas
--
Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto,
\ would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert
next prev parent reply other threads:[~2001-02-27 17:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-02-27 16:43 Dynamically altering code segments Collins, Tom
2001-02-27 17:05 ` Andreas Dilger [this message]
2001-02-27 18:15 richardj_moore
2001-02-27 19:04 Collins, Tom
2001-02-28 1:22 ` Karim Yaghmour
2001-03-01 2:58 Jeremy Jackson
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