Re: patches to actually use markers?

["Frank Ch. Eigler" <fche at redhat dot com>]

Hi -

On Fri, Nov 16, 2007 at 03:10:15PM -0500, Mathieu Desnoyers wrote:
> [...]
> > How would this syscall specific function get ebx or the string,
> > without ebx (or regs) being passed as marker arguments?

> That's the idea : in the syscall specific function (not in
> syscall_trace()), we add another marker that takes the syscall
> specific arguments as parameter. I think we use the same approach
> there.

I see.  Yes, per-systemcall markers would be welcome by our group, and
ones not dependent on TIF_TRACE or whatnot even more so.  But were
trying not to get too optimistic.


> What I was saying is that we can't extract the string from
> syscall_trace() because we have no idea it is a string.

If "we" is a marker callback function that is given the system call
number, it can be taught.  This is the sort of thing we do currently
in systemtap script code based upon kprobes.

- FChE