linux-kernel - Re: [PATCH v2] perf/core: restore __perf_remove_from_context when DETACH

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: <20250603125056.GI39944@noisy.programming.kicks-ass.net>
Date: Tue, 3 Jun 2025 14:50:56 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: David Wang <00107082@....com>
Cc: mingo@...hat.com, acme@...nel.org, namhyung@...nel.org,
	mingo@...nel.org, yeoreum.yun@....com, leo.yan@....com,
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] perf/core: restore __perf_remove_from_context when
 DETACH_EXIT not set

On Tue, Jun 03, 2025 at 06:44:58PM +0800, David Wang wrote:


> (As yeoreum.yun@....com pointed out,  the change in perf_remove_from_context() made
> perf_event_set_state() happened before list_del_event(), resulting in perf_cgroup_event_disable()
> not called.)

Aah, d'0h. Let me see what we should do there.

> My suggestion here is to confine the effect of commit a3c3c66670ce only to call chain
> perf_event_exit_event() --> __perf_remove_from_context()
> 
> 
> (But this v2 version is totally wrong, should be ignored; it breaks commit a3c3c66670ce)

Right. Because we moved that state update earlier because
perf_child_detach() wants up-to-date timestamps.