Re: [PATCHv2 2/4] coresight: tmc-etf: Fix NULL ptr dereference in tmc_enable_etf_sink_perf()

[Peter Zijlstra]

On Fri, Oct 23, 2020 at 09:49:53AM +0100, Suzuki Poulose wrote:
> On 10/23/20 8:39 AM, Peter Zijlstra wrote:

> > So then I don't understand the !->owner issue, that only happens when
> > the task dies, which cannot be concurrent with event creation. Are you
> 
> Part of the patch from Sai, fixes this by avoiding the dereferencing
> after event creation (by caching it). But the kernel events needs
> fixing.

I'm fundamentally failing here. Creating a link to the sink is strictly
event-creation time. Why would you ever need it again later? Later you
already have the sink setup.