Re: [PATCH 0/6] uprobes/tracing: uretprobes

[Anton Arapov <anton@redhat.com>]

On Mon, Apr 01, 2013 at 06:08:27PM +0200, Oleg Nesterov wrote:
> On 03/29, Oleg Nesterov wrote:
> >
> > uretprobes code is almost ready, we need to teach trace_uprobe.c
> > to support them.
> >
> > This looks simple, but there is a nasty complication. We do not
> > want to copy-and-paste the code like trace_kprobe.c does. Just look
> > at kprobe_event_define_fields() and kretprobe_event_define_fields().
> > They are non-trivial but almost identical. And there are a lot more
> > examples.
> >
> > So I'd like to send 4/4 for review before I'll do other changes.
> > The patch itself doesn't make sense and complicates the source code a
> > bit. But note how easy we can change, say, uprobe_event_define_fields(),
> >
> > 	-	DEFINE_FIELD(vaddr[0], FIELD_STRING_IP);
> > 	-	size = SIZEOF_TRACE_ENTRY(1);
> > 	+	if (!trace_probe_is_return(tu)) {
> > 	+		DEFINE_FIELD(vaddr[0], FIELD_STRING_IP);
> > 	+		size = SIZEOF_TRACE_ENTRY(1);
> > 	+	} else {
> > 	+		DEFINE_FIELD(vaddr[0], FIELD_STRING_FUNC);
> > 	+		DEFINE_FIELD(vaddr[1], FIELD_STRING_RETIP);
> > 	+		size = SIZEOF_TRACE_ENTRY(2);
> > 	+	}
> >
> > without copy-and-paste. The same simple change is possible for other
> > helpers playing with uprobe_trace_entry_head.
> 
> And the rest of the necessary changes to support uretprobes.
> 
> To remind, this is on top of Anton's uretprobes implementation which is
> not finished yet. This series can't be even compiled, but I think it can
> be already reviewed. All it needs to compile is the new
> uprobe_consumer->ret_handler().
> 
> Oleg.
> 
>  kernel/trace/trace_uprobe.c |  152 +++++++++++++++++++++++++++++++++++--------
>  1 files changed, 124 insertions(+), 28 deletions(-)
>

I've played with this patch-set and it works.

Tested-by: Anton Arapov <anton@redhat.com>