On Wed, Jun 28, 2017 at 09:48:27AM -0700, Kyle Huey wrote: > On Wed, Jun 28, 2017 at 3:56 AM, Mark Rutland <mark.rutl...@arm.com> wrote: > > @@ -6101,6 +6116,12 @@ void perf_prepare_sample(struct perf_event_header > > *header, > > struct perf_output_handle handle; > > struct perf_event_header header; > > > > + /* > > + * For security, drop the skid kernel samples if necessary. > > + */ > > + if (!sample_is_allowed(event, regs)) > > + return ret; > > Just a bare return here.
Ugh, yes. Sorry about that. I'll fix that up. [...] > I can confirm that with that fixed to compile, this patch fixes rr. Thanks for giving this a go. Having thought about this some more, I think Vince does make a good point that throwing away samples is liable to break stuff, e.g. that which only relies on (non-sensitive) samples. It still seems wrong to make up data, though. Maybe for exclude_kernel && !exclude_user events we can always generate samples from the user regs, rather than the exception regs. That's going to be closer to what the user wants, regardless. I'll take a look tomorrow. Thanks, Mark.
