From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 670EC1CAA6E; Thu, 8 May 2025 21:44:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746740640; cv=none; b=h5wEi2Z6QbVWL1XNSdXBO1GWe+enme67MKMDsUcXWK/bG9+Aubu/wLgXb6zlFWkkMsRZsKje3cvfeYfI+J5Tmm39s6yd5GhV/YgjxSKO1OiQh6QkeZXr0CslCHKm5wOZKc9VaBLi91uJVLXX7TdpwWWsh29aGEzhnuuUuJGEEc8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746740640; c=relaxed/simple; bh=2XM0ycqF9U6sa+FgoRGJnyBhv3k0LGN8UkGCg3UhoMk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nn1pq8FvM/TVSflWNsVaZXyDeedCLmY8AS3iEL11y5zIQoCP83R3BU4DFdPiL1BEtlT9w5VDpIfLMUwv3y4Mgl2RJwJA5pbhiORzS5bxkk9kAOMEYq7TMIOJ2n5+ZYwK3WKRSevS86LfYkT3h/POawsOsSAbn5WSGQ4upipW1f0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aUDJQ7TM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aUDJQ7TM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED364C4CEE7; Thu, 8 May 2025 21:43:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746740640; bh=2XM0ycqF9U6sa+FgoRGJnyBhv3k0LGN8UkGCg3UhoMk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aUDJQ7TMLaRB9cnLeSgzoWJEtdQBcpXGxXX3iQdgb/fgkky2ebvtCYpZLmdhci48l TmnoOj3mUAygZZYoVHtWPbVtJwha3ocNCa/+16PP4BWZOZW1jFnjzAOEKwhKUi5L2y 5zWHAGai3TXN2tDplVbRSkVB5waYHoWYunAg1hrBW2YRVARQ0IcwrL/oEiIppnRDXV 0Ukl+4He2OzrLJSIcN6FXMY4Qsf7zMhkPe1AD/fH/BtyfpPebsNz2SleZtTATnaFL+ fxXp1GUBTm/t/5K6/IogD15G9TC1NKOE+7iJWNckXd3MPJc5pXgm41L9zNDVRo1RWm lGJFmu4+Ycc7Q== Date: Thu, 8 May 2025 23:43:57 +0200 From: Frederic Weisbecker To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org, x86@kernel.org Subject: Re: [tip: perf/core] perf: Fix irq work dereferencing garbage Message-ID: References: <174670046919.406.15885032121099672652.tip-bot2@tip-bot2> <20250508194605.GA8552@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250508194605.GA8552@noisy.programming.kicks-ass.net> Le Thu, May 08, 2025 at 09:46:05PM +0200, Peter Zijlstra a écrit : > On Thu, May 08, 2025 at 09:11:23PM +0200, Frederic Weisbecker wrote: > > Le Thu, May 08, 2025 at 10:34:29AM -0000, tip-bot2 for Frederic Weisbecker a écrit : > > > The following commit has been merged into the perf/core branch of tip: > > > > > > Commit-ID: 88d51e795539acd08bce028eff3aa78748b847a8 > > > Gitweb: https://git.kernel.org/tip/88d51e795539acd08bce028eff3aa78748b847a8 > > > Author: Frederic Weisbecker > > > AuthorDate: Mon, 28 Apr 2025 13:11:47 +02:00 > > > Committer: Peter Zijlstra > > > CommitterDate: Fri, 02 May 2025 12:40:40 +02:00 > > > > > > perf: Fix irq work dereferencing garbage > > > > > > The following commit: > > > > > > da916e96e2de ("perf: Make perf_pmu_unregister() useable") > > > > > > has introduced two significant event's parent lifecycle changes: > > > > > > 1) An event that has exited now has EVENT_TOMBSTONE as a parent. > > > This can result in a situation where the delayed wakeup irq_work can > > > accidentally dereference EVENT_TOMBSTONE on: > > > > > > CPU 0 CPU 1 > > > > This is missing the most important (and boring) part of the changelog :-) > > > > > Signed-off-by: Peter Zijlstra (Intel) > > > > And I suspect some automatic check will also yell at some point at missing Sob. > > Doh, script fail :/ > > Let me go fix. Looks good, thanks! -- Frederic Weisbecker SUSE Labs