Re: [PATCH v1 0/2] perf: Drop leaked kernel samples

Peter Zijlstra
2018-06-15T07:45:17Z

On Fri, Jun 15, 2018 at 06:03:21PM +0800, Jin Yao wrote:
> On workloads that do a lot of kernel entry/exits we see kernel
> samples, even though :u is specified. This is due to skid existing.
>
> This might be a security issue because it can leak kernel addresses even
> though kernel sampling support is disabled.
>
> One patch "perf/core: Drop kernel samples even though :u is specified"
> was posted in last year but it was reverted because it introduced a
> regression issue that broke the rr-project.
>
> Now this patch set uses sysctl to control the dropping of leaked
> kernel samples.

So what happened to the suggestion of keeping the samples but 0-stuffing
all the tricky bits?