On Fri, Oct 09, 2020 at 10:37:51AM +0100, Will Deacon wrote: > On Fri, Oct 09, 2020 at 11:09:27AM +0200, Peter Zijlstra wrote:
> > Patch 4 makes it all far worse by exposing it to pretty much everybody. > > > > Now, I think we can fix at least the user mappings with the below delta, > > but if archs are using non-page-table MMU sizes we'll need arch helpers. > > > > ARM64 is in that last boat. > > > > Will, can you live with the below, if not, what would you like to do, > > make the entire function __weak so that you can override it, or hook > > into it somewhere? > > Hmm, so I don't think we currently have any PMUs that set 'data->addr' > on arm64, in which case maybe none of this currently matters for us. > > However, I must admit that I couldn't figure out exactly what gets exposed > to userspace when the backend drivers don't look at the sample_type or > do anything with the addr field. Patch 4: https://lkml.kernel.org/r/20201001135749.2804-5-kan.li...@linux.intel.com is the one that exposes this to everybody with perf support. It will then report the page-size for the code address (SAMPLE_IP).