Re: [PATCH] perf: Fix sys_perf_event_open() race against self

From: Ravi Bangoria
Date: Thu Nov 17 2022 - 08:39:00 EST


On 17-Nov-22 5:29 PM, Borislav Petkov wrote:
> On Thu, Nov 17, 2022 at 04:29:31PM +0530, Ravi Bangoria wrote:
>> I do agree that more tests are always better. Though, this simple program
>> was to test a _specific race condition_ which no longer exists in kernel.
>> So even if we add it, what would it test?
>
> It would make sure that race doesn't happen again. Or are you saying it
> will never ever happen so no need? Because we never ever rewrite the
> kernel?
>
> Lemme save us some time: this test is dirt cheap. It is good to have so
> that multithreaded sys_perf_event_open() is exercised. And once it is
> there, someone else might have a look at it and improve it more or reuse
> it for another test.
>
> And there are no downsides.
>
> If you're still not convinced, lemme know and I'll turn it into a proper
> patch and submit it.

I'll do it :)

Thanks,
Ravi