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 78528EB64DA for ; Fri, 14 Jul 2023 08:48:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235555AbjGNIsR (ORCPT ); Fri, 14 Jul 2023 04:48:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235596AbjGNIsD (ORCPT ); Fri, 14 Jul 2023 04:48:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30A1A26BC; Fri, 14 Jul 2023 01:48:02 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9BDE461CAF; Fri, 14 Jul 2023 08:48:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F883C433C7; Fri, 14 Jul 2023 08:47:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689324480; bh=SuXBSUhf6SaAYBNbJx5KDu5zbWTFCohaWvvlrJaNPNE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sPSnjUUMNemRkawp16dG6Pf6q16Xt7vtm+dJXRxbmdioSVsJbCJgEHdX/ywGRcqEC KTFbCy4Lz3P58KATKpsAcaGIXSOpgO9mhvwkSX1wjKoqVmRqtNkNWcTL1tD8DYuBrd PLfOOc9HeqoLwfnwfIuX0bV0oV9dmC6hgjfFzNdaep2eMJAP1VYHGq7xJEjDHf3Sp0 DuBEuDSD5k2NVqV6Ku1L1oTFxJvfLv9Zu3+4/0vU8BhLA9teqUwxJx8bnNkgitC1QW Tntjwfd/mXheb23yj/t8tpo/y0ApFKtejMQ+QXYRR/Sa8Jvqhf5P9H3L04IKUIGbr7 wA5v+j/eJ1TBg== Date: Fri, 14 Jul 2023 17:47:57 +0900 From: Masami Hiramatsu (Google) To: Steven Rostedt Cc: LKML , Linux Trace Kernel , Masami Hiramatsu , Mark Rutland , Zheng Yejian Subject: Re: [PATCH 2/2] tracing: Add free_trace_iter_content() helper function Message-Id: <20230714174757.4ab9157a2edb32d35224edfb@kernel.org> In-Reply-To: <20230713114700.450e7a17@gandalf.local.home> References: <20230713114510.04c452ca@gandalf.local.home> <20230713114700.450e7a17@gandalf.local.home> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Thu, 13 Jul 2023 11:47:00 -0400 Steven Rostedt wrote: > From: "Steven Rostedt (Google)" > > As the trace iterator is created and used by various interfaces, the clean > up of it needs to be consistent. Create a free_trace_iter_content() helper > function that frees the content of the iterator and use that to clean it > up in all places that it is used. > > Signed-off-by: Steven Rostedt (Google) > --- > kernel/trace/trace.c | 40 ++++++++++++++++++++++++++++------------ > 1 file changed, 28 insertions(+), 12 deletions(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 1c370ffbe062..3f38250637e2 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -4815,6 +4815,25 @@ static const struct seq_operations tracer_seq_ops = { > .show = s_show, > }; > > +/* > + * Note, as iter itself can be allocated and freed in different > + * ways, this function is only used to free its content, and not > + * the iterator itself. The only requirement to all the allocations > + * is that it must zero all fields (kzalloc), as freeing works with > + * ethier allocated content or NULL. > + */ > +static void free_trace_iter_content(struct trace_iterator *iter) > +{ > + /* The fmt is either NULL, allocated or points to static_fmt_buf */ > + if (iter->fmt != static_fmt_buf) > + kfree(iter->fmt); > + > + kfree(iter->temp); > + kfree(iter->buffer_iter); > + mutex_destroy(&iter->mutex); > + free_cpumask_var(iter->started); This doesn't kfree(iter->trace) because iter->trace is just a reference if I understand correctly. > +} > + > static struct trace_iterator * > __tracing_open(struct inode *inode, struct file *file, bool snapshot) > { > @@ -4922,8 +4941,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot) > > fail: > mutex_unlock(&trace_types_lock); > - kfree(iter->temp); > - kfree(iter->buffer_iter); > + free_trace_iter_content(iter); > release: > seq_release_private(inode, file); > return ERR_PTR(-ENOMEM); > @@ -5002,11 +5020,7 @@ static int tracing_release(struct inode *inode, struct file *file) > > mutex_unlock(&trace_types_lock); > > - mutex_destroy(&iter->mutex); > - free_cpumask_var(iter->started); > - kfree(iter->fmt); > - kfree(iter->temp); > - kfree(iter->buffer_iter); > + free_trace_iter_content(iter); > seq_release_private(inode, file); > > return 0; > @@ -6709,7 +6723,12 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) > } > > trace_seq_init(&iter->seq); > - iter->trace = tr->current_trace; > + > + iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL); > + if (!iter->trace) > + goto fail; > + > + *iter->trace = *tr->current_trace; Hmm, you allocate iter->trace here (again) > > if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { > ret = -ENOMEM; > @@ -6763,10 +6782,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) > > mutex_unlock(&trace_types_lock); > > - free_cpumask_var(iter->started); > - kfree(iter->fmt); > - kfree(iter->temp); > - mutex_destroy(&iter->mutex); But there is no kfree(iter->trace). Thank you, > + free_trace_iter_content(iter); > kfree(iter); > > trace_array_put(tr); > -- > 2.40.1 > -- Masami Hiramatsu (Google)