linux-kernel - Re: [PATCH v2 24/24] perf: Make perf_pmu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2cf234bc-de9b-4017-a671-710a55e5a35e@amd.com>
Date: Fri, 14 Feb 2025 09:27:12 +0530
From: Ravi Bangoria <ravi.bangoria@....com>
To: Peter Zijlstra <peterz@...radead.org>
Cc: mingo@...nel.org, lucas.demarchi@...el.com, linux-kernel@...r.kernel.org,
 willy@...radead.org, acme@...nel.org, namhyung@...nel.org,
 mark.rutland@....com, alexander.shishkin@...ux.intel.com, jolsa@...nel.org,
 irogers@...gle.com, adrian.hunter@...el.com, kan.liang@...ux.intel.com,
 Ravi Bangoria <ravi.bangoria@....com>
Subject: Re: [PATCH v2 24/24] perf: Make perf_pmu_unregister() useable

On 13-Feb-25 6:38 PM, Peter Zijlstra wrote:
> On Thu, Feb 13, 2025 at 01:22:55PM +0530, Ravi Bangoria wrote:
>>> Does this work?
>>>
>>> --- a/kernel/events/core.c
>>> +++ b/kernel/events/core.c
>>> @@ -2303,6 +2303,7 @@ static void perf_child_detach(struct per
>>>  
>>>  	sync_child_event(event);
>>>  	list_del_init(&event->child_list);
>>> +	event->parent = NULL;
>>>  }
>>>  
>>>  static bool is_orphaned_event(struct perf_event *event)
>>
>> Apparently not, it ends up with:
>>
>>   ------------[ cut here ]------------
>>   WARNING: CPU: 145 PID: 5459 at kernel/events/core.c:281 event_function+0xd2/0xf0
> 
> Durr, do you have an updated test case?

This one triggered with just perf_fuzzer run (without my tinypmu test).

But in general, to test the whole series, I ran perf_fuzzer simultaneously
with my tinypmu tests:

  term1~$ echo -1 | sudo tee /proc/sys/kernel/perf_event_paranoid; while true; do ./perf_fuzzer; done
  term2~$ cd ~/tinypmu; make clean; make; while true; do sudo bash tinypmu-u.sh; done

Thanks,
Ravi