From: Josh Stone <jistone@redhat.com>
To: Eric Wong <normalperson@yhbt.net>
Cc: Jeff Johnston <jjohnstn@redhat.com>, systemtap@sourceware.org
Subject: Re: Trying to get an embedded C function to use file I/O
Date: Mon, 19 Aug 2013 19:11:00 -0000 [thread overview]
Message-ID: <52126DC3.7070707@redhat.com> (raw)
In-Reply-To: <20130816181732.GA6552@dcvr.yhbt.net>
On 08/16/2013 11:17 AM, Eric Wong wrote:
> I think guru mode runs the code in kernel space. I tried using
> strftime() the other day and could not. Maybe dyninst lets one use
> glibc, I haven't looked into it more...
Correct - the entire script runs in kernel mode, so any embedded-C you
add can only use kernel headers and functions. This is not directly an
artifact of guru, really -- it's just that guru is required to let you
write embedded-c at all. For your own good. :)
And you're also correct that --runtime=dyninst can use glibc, because in
this mode the script will be running as a plain shared library. In
theory, you could use *any* header and library on your system, although
I don't think we currently give any way to add compiler flags. You also
have to be aware of the process space though, e.g. a file you open() in
one process isn't going to be open in all involved processes.
next prev parent reply other threads:[~2013-08-19 19:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-16 17:41 Jeff Johnston
2013-08-16 18:17 ` Eric Wong
2013-08-19 19:11 ` Josh Stone [this message]
2013-08-17 23:48 ` Frank Ch. Eigler
2013-08-19 16:38 ` Jeff Johnston
2013-08-19 22:02 ` Frank Ch. Eigler
2013-08-21 21:24 ` Jeff Johnston
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