Re: [PATCH v17 11/16] fprobe: Rewrite fprobe on function-graph tracer

[Google]

On Mon, 21 Oct 2024 18:31:39 +0200
Heiko Carstens <hca@xxxxxxxxxxxxx> wrote:

> > > Please note that this only works for addresses in the kernel address
> > > space. For user space the full 64 bit address range (minus the top
> > > page) can be used for user space applications.
> > 
> > I wonder what is the unsigned long size (stack entry size) of the
> > s390? is it 64bit?
> 
> The s390 kernel is 64 bit only. So unsigned long is 64 bit as well.
> 

Ah, got it.

> > > I'm just writing this
> > > here, just in case something like this comes up for uprobes or
> > > something similar as well.
> > 
> > I'm considering another solution if it doesn't work. Of course if
> > above works, it is the best compression ratio.
> 
> I'm think we are not talking about uprobes here, and everything ftrace
> related would just work (tm) with the first four MSBs assumed to be
> zero.

yeah, but we still have other 32bit architectures support (e.g. i386, arm).

Thank you,

-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>