Tracing through init transitions

Tracing through init transitions

[Alan D. Brunelle]

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I'm trying to trace the opening of files under /proc & /sys during the 
transition from single-user to run level 3, but either the tracing 
doesn't start or gets killed. I've tried various means of trying to 
daemonize the systemtap run (including starting this via an rc script 
utilizing the "daemon" function, and trying the -F option), but nothing 
I've tried seems to work.

Any suggestions?

Thanks (please CC me as I'm no longer on the systemtap mailing list),
Alan
PS. I've attached the script, although I doubt there's anything 
particular in there that would make a difference...

[-- Attachment #2: opens.stp --]
[-- Type: text/plain, Size: 425 bytes --]

#! /usr/bin env stap

global opens[4000]

function print_opens() {
	foreach ([exe, fn, wr] in opens-) {
		if (wr) str = "WR"
		else	str = "RD"

		printf("%4d %-20s: %s %s\n", opens[exe, fn, wr], exe, str, fn)
	}
}

probe kernel.function("sys_open") {
	fn = user_string($filename)
	if (substr(fn, 0, 6) == "/proc/" || substr(fn, 0, 5) == "/sys/")
		opens[execname(), fn, $flags & 1] ++
}

probe end {
	print_opens()
	exit()
}

Re: Tracing through init transitions

[Jim Keniston]

On Fri, 2010-04-30 at 15:44 -0400, Alan D. Brunelle wrote:
> I'm trying to trace the opening of files under /proc & /sys during the 
> transition from single-user to run level 3, but either the tracing 
> doesn't start or gets killed. I've tried various means of trying to 
> daemonize the systemtap run (including starting this via an rc script 
> utilizing the "daemon" function, and trying the -F option), but nothing 
> I've tried seems to work.
> 
> Any suggestions?
> 
> Thanks (please CC me as I'm no longer on the systemtap mailing list),
> Alan
> PS. I've attached the script, although I doubt there's anything 
> particular in there that would make a difference...

> plain text document attachment (opens.stp)
> #! /usr/bin env stap

"bin env" should be "bin/env", right?

> 
> global opens[4000]

Jim

Re: Tracing through init transitions

[Frank Ch. Eigler]

"Alan D. Brunelle" <alan.brunelle@hp.com> writes:

> I'm trying to trace the opening of files under /proc & /sys during the
> transition from single-user to run level 3, but either the tracing
> doesn't start or gets killed. [...]

The script looks fine.  If that #! path fixing doesn't help, please
supply more data regarding the commands you've tried and errors you've
seen. "stap --vp 00005 ..." for example.

- FChE