From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE6C4C433FE for ; Mon, 24 Jan 2022 09:42:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229514AbiAXJmc (ORCPT ); Mon, 24 Jan 2022 04:42:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54086 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236510AbiAXJkg (ORCPT ); Mon, 24 Jan 2022 04:40:36 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9D3AC061751 for ; Mon, 24 Jan 2022 01:40:35 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9310CB80EE0 for ; Mon, 24 Jan 2022 09:40:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6D4CC340E1; Mon, 24 Jan 2022 09:40:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643017233; bh=1tTifthnsni0ibQGbH3QAEgOXUWfWXejv0g3Rel0IPg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E7xsq++9CDaupWmkEoZ2dsbsB2tuJLOA0UI/LEsILprLFIItElGeRRJVeSUi0/EuG Kx3BAXhsAl8E7GZKwBGFci9fB/ylPP7ybsZqDKzjYDWx7rWYPKAUj+/AwktMnU/ZoK wHEy2NIbrdj/gH0iSwqqw8l/nZjAw/Ocf0iLVK3Y= Date: Mon, 24 Jan 2022 10:40:29 +0100 From: Greg KH To: Nikita Yushchenko Cc: bristot@kernel.org, rostedt@goodmis.org, stable@vger.kernel.org Subject: Re: [PATCH 5.15.y] tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails Message-ID: References: <1642956398125157@kroah.com> <20220124053356.495768-1-nikita.yushchenko@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220124053356.495768-1-nikita.yushchenko@virtuozzo.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Jan 24, 2022 at 08:33:57AM +0300, Nikita Yushchenko wrote: > commit 0878355b51f5f26632e652c848a8e174bb02d22d upstream. > > If start_per_cpu_kthreads() called from osnoise_workload_start() returns > error, event hooks are left in broken state: unhook_irq_events() called > but unhook_thread_events() and unhook_softirq_events() not called, and > trace_osnoise_callback_enabled flag not cleared. > > On the next tracer enable, hooks get not installed due to > trace_osnoise_callback_enabled flag. > > And on the further tracer disable an attempt to remove non-installed > hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func(). > > Fix the error path by adding the missing part of cleanup. > While at this, introduce osnoise_unhook_events() to avoid code > duplication between this error path and normal tracer disable. > > Link: https://lkml.kernel.org/r/20220109153459.3701773-1-nikita.yushchenko@virtuozzo.com > > Cc: stable@vger.kernel.org > Fixes: bce29ac9ce0b ("trace: Add osnoise tracer") > Acked-by: Daniel Bristot de Oliveira > Signed-off-by: Nikita Yushchenko > Signed-off-by: Steven Rostedt > --- > kernel/trace/trace_osnoise.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) Now queued up, thanks. greg k-h