[lttng-dev] LTTng system call tracing on ARM

[Pierre-Luc St-Charles]

Here are the links I stashed a while back about previous patching attempts
to add syscall tracepoints to the ARM kernel :

Most promising:
http://www.spinics.net/lists/arm-kernel/msg166419.html

Earlier draft(s):
http://lists.infradead.org/pipermail/linux-arm-kernel/2012-February/086974.html
https://lkml.org/lkml/2011/12/1/131
http://comments.gmane.org/gmane.linux.ports.arm.kernel/141933

I believe the first link shows the most refined patch there is out there,
but it might take some minor tinkering to apply it to a different kernel
version. I briefly tried to apply it to the 3.0.31 kernel, but it's a bit
out of my 'tinkering' range, and I never finished it.


Good luck!

-PL



On Wed, Apr 10, 2013 at 9:02 AM, Jan Glauber <jan.glauber at gmail.com> wrote:

> On Wed, Apr 10, 2013 at 08:37:18AM -0400, PLSTC wrote:
> > Hey Jan,
> >
> > I cannot speak on behalf of everyone here, but during our attempt to port
> > LTTng to Android, we also noticed that the kernels we were using (3.0.x)
> > were nowhere near the requirements for syscall tracepoints support. I
> > believe such support was added on x86/64 way earlier (early 3.x) than on
> > ARM, which is why it was included in LTTng's modules a while ago. Simply
> > put, the ARM kernel is late.
>
> OK, so for ARM kernel version 3.6 is the minimum unless the syscall
> tracepoint
> support is backported.
>
> > There are a few actuals ways to 'enable' syscall tracepoints support on
> > early ARM kernels, but they all including a bit of kernel
> hacking/patching.
> > I could send you some links if you're interested in that.
>
> Yes, sure!
>
> --Jan
>
> > -PL
> > On Apr 10, 2013 4:40 AM, "Jan Glauber" <jan.glauber at gmail.com> wrote:
> >
> > > Hi,
> > >
> > > I want to use LTTng for system call tracing on ARM. Now lttng-modules
> seems
> > > to support system call tracing on ARM already since
> > > "8f4f80e LTTng Modules ARM syscall instrumentation".
> > >
> > > But I wonder how that worked since lttng-syscalls.c is only build under
> > > CONFIG_HAVE_SYSCALL_TRACEPOINTS and that was added to ARM only with
> kernel
> > > 3.6
> > > (much after than the lttng-modules commit).
> > >
> > > Am I missing something? Is system call tracing working on ARM with the
> > > upstream
> > > LTTng version?
> > >
> > > thanks,
> > > Jan
> > >
> > > _______________________________________________
> > > lttng-dev mailing list
> > > lttng-dev at lists.lttng.org
> > > http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
> > >
>
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