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 B3B03EB64DD for ; Fri, 28 Jul 2023 23:08:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231540AbjG1XIZ (ORCPT ); Fri, 28 Jul 2023 19:08:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230274AbjG1XIY (ORCPT ); Fri, 28 Jul 2023 19:08:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45EC7269E; Fri, 28 Jul 2023 16:08:23 -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 D64D36220B; Fri, 28 Jul 2023 23:08:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4F85C433C8; Fri, 28 Jul 2023 23:08:20 +0000 (UTC) Date: Fri, 28 Jul 2023 19:08:19 -0400 From: Steven Rostedt To: "Masami Hiramatsu (Google)" Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Mark Rutland , Andrew Morton Subject: Re: [PATCH v2 2/2] tracing: Add free_trace_iter_content() helper function Message-ID: <20230728190819.544a48eb@rorschach.local.home> In-Reply-To: <20230726224213.f5f3a23d207ffedeee291d22@kernel.org> References: <20230715141213.970003974@goodmis.org> <20230715141348.341887497@goodmis.org> <20230726224213.f5f3a23d207ffedeee291d22@kernel.org> X-Mailer: Claws Mail 3.17.8 (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 Wed, 26 Jul 2023 22:42:13 +0900 Masami Hiramatsu (Google) wrote: > On Sat, 15 Jul 2023 10:12:15 -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) > > Looks good to me. > > Reviewed-by: Masami Hiramatsu (Google) > > BTW, this adds iter->fmt != static_fmt_buf check. Is it a kind of fix? No, because all of the callers shouldn't actually set it to that. I added the if statement in case one of the places that do set it does call this. In other words, I added the if statement to make it more robust and prevent a bug in the future ;-) -- Steve > > Thank you, > > > --- > > kernel/trace/trace.c | 33 ++++++++++++++++++++++----------- > > 1 file changed, 22 insertions(+), 11 deletions(-) > > > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > > index 1c370ffbe062..8775930aa545 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); > > +} > > + > > 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; > > @@ -6763,10 +6777,7 @@ 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); > > + free_trace_iter_content(iter); > > kfree(iter); > > > > trace_array_put(tr); > > -- > > 2.40.1 > >