Re: [PATCH v1 0/2] perf: Drop leaked kernel samples
From: Peter Zijlstra
Date: Fri Jun 15 2018 - 03:45:21 EST
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?