Re: [PATCH v2 perf/core] perf script: fix a use after free crash.

From: Krister Johansen
Date: Thu Nov 10 2016 - 19:40:57 EST


On Wed, Oct 26, 2016 at 11:44:53AM -0200, Arnaldo Carvalho de Melo wrote:
> Em Tue, Oct 25, 2016 at 05:20:10PM -0700, Krister Johansen escreveu:
> > On Tue, Oct 11, 2016 at 02:28:39AM -0700, Krister Johansen wrote:
> > > If dso__load_kcore frees all of the existing maps, but one has already
> > > been attached to a callchain cursor node, then we can get a SIGSEGV in
> > > any function that happens to try to use this invalid cursor. Use the
> > > existing map refcount mechanism to forestall cleanup of a map until the
> > > cursor iterates past the node.
> >
> > It has been a couple of weeks since I sent out v2 of this patch. I
> > understand that folks here have plenty of irons in the fire, but I
> > wanted to double-check that nobody was waiting on me for additional
> > information or changes.
>
> It was a mix of waiting for more people to review it, or for Masami to
> run its refcount debugger on it, ended up falling thru the cracks.
>
> I'll try to process it now.

Thanks. As part of processing this did you run into any problems?
Would you like me to rebase against the latest perf/core and re-send the
patch?

-K