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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F2D7C43381 for ; Wed, 20 Feb 2019 18:46:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3432218C3 for ; Wed, 20 Feb 2019 18:46:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726445AbfBTSqu (ORCPT ); Wed, 20 Feb 2019 13:46:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:49824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725842AbfBTSqu (ORCPT ); Wed, 20 Feb 2019 13:46:50 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0321120859; Wed, 20 Feb 2019 18:46:48 +0000 (UTC) Date: Wed, 20 Feb 2019 13:46:47 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , "zhangyi (F)" Subject: Re: [for-next][PATCH 13/29] tracing: No need to free iter->trace in fail path of tracing_open_pipe() Message-ID: <20190220134647.3be6b506@gandalf.local.home> In-Reply-To: <20190220183805.422405135@goodmis.org> References: <20190220183737.034634614@goodmis.org> <20190220183805.422405135@goodmis.org> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 20 Feb 2019 13:37:50 -0500 Steven Rostedt wrote: > From: "zhangyi (F)" > > Commit d716ff71dd12 ("tracing: Remove taking of trace_types_lock in > pipe files") use the current tracer instead of the copy in > tracing_open_pipe(), but it forget to remove the freeing sentence in > the error path. > > [ Note, this is harmless because kfree(NULL) is allowed and iter is > allocated with kzalloc() making iter->trace = NULL -- S. Rostedt ] Bah, I forgot to update this. I haven't pushed to linux-next yet. As Zhangyi replied, this is a real issue. I just wished the real issue was explained in the change log. I'm going to rebase this to update the change log (no code changes, so no need to run the tests again), and also, I'll add a Cc stable. No point in sending this out as a separate patch either, because the merge window is going to open soon. -- Steve > > Link: http://lkml.kernel.org/r/1550060946-45984-1-git-send-email-yi.zhang@huawei.com > > Fixes: d716ff71dd12 ("tracing: Remove taking of trace_types_lock in pipe files") > Signed-off-by: zhangyi (F) > Signed-off-by: Steven Rostedt (VMware) > --- > kernel/trace/trace.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index c521b7347482..b583ff7656bb 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5624,7 +5624,6 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) > return ret; > > fail: > - kfree(iter->trace); > kfree(iter); > __trace_array_put(tr); > mutex_unlock(&trace_types_lock);