From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751794AbaF0SO1 (ORCPT ); Fri, 27 Jun 2014 14:14:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6822 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750862AbaF0SO0 (ORCPT ); Fri, 27 Jun 2014 14:14:26 -0400 Date: Fri, 27 Jun 2014 19:01:46 +0200 From: Oleg Nesterov To: Steven Rostedt Cc: Masami Hiramatsu , Namhyung Kim , Srikar Dronamraju , Tom Zanussi , "zhangwei(Jovi)" , linux-kernel@vger.kernel.org Subject: [PATCH 4/4] tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable() Message-ID: <20140627170146.GA18332@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140627170116.GA18298@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(). 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; } -- 1.5.5.1