Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752187AbaF3Ltf (ORCPT ); Mon, 30 Jun 2014 07:49:35 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:33135 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751564AbaF3Lt3 (ORCPT ); Mon, 30 Jun 2014 07:49:29 -0400 Message-ID: <53B14EC2.9000508@hitachi.com> Date: Mon, 30 Jun 2014 20:49:22 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Oleg Nesterov Cc: Steven Rostedt , Namhyung Kim , Srikar Dronamraju , Tom Zanussi , "zhangwei(Jovi)" , linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/4] tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable() References: <20140627170146.GA18332@redhat.com> In-Reply-To: <20140627170146.GA18332@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2014/06/28 2:01), Oleg Nesterov wrote: > The usage of uprobe_buffer_enable() added by dcad1a20 is very wrong, > > 1. uprobe_buffer_enable() and uprobe_buffer_disable() are not balanced, > _enable() should be called only if !enabled. > > 2. If uprobe_buffer_enable() fails probe_event_enable() should clear > tp.flags and free event_file_link. > > 3. If uprobe_register() fails it should do uprobe_buffer_disable(). Looks good to me ;) Reviewed-by: Masami Hiramatsu Thanks, > > Signed-off-by: Oleg Nesterov > --- > kernel/trace/trace_uprobe.c | 31 +++++++++++++++++++------------ > 1 files changed, 19 insertions(+), 12 deletions(-) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index c4cf0ab..3c9b97e 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -911,26 +911,33 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file, > tu->tp.flags |= TP_FLAG_PROFILE; > } > > - ret = uprobe_buffer_enable(); > - if (ret < 0) > - return ret; > - > WARN_ON(!uprobe_filter_is_empty(&tu->filter)); > > if (enabled) > return 0; > > + ret = uprobe_buffer_enable(); > + if (ret) > + goto err_flags; > + > tu->consumer.filter = filter; > ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); > - if (ret) { > - if (file) { > - list_del(&link->list); > - kfree(link); > - tu->tp.flags &= ~TP_FLAG_TRACE; > - } else > - tu->tp.flags &= ~TP_FLAG_PROFILE; > - } > + if (ret) > + goto err_buffer; > > + return 0; > + > + err_buffer: > + uprobe_buffer_disable(); > + > + err_flags: > + if (file) { > + list_del(&link->list); > + kfree(link); > + tu->tp.flags &= ~TP_FLAG_TRACE; > + } else { > + tu->tp.flags &= ~TP_FLAG_PROFILE; > + } > return ret; > } > > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/