From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756912AbaF3VwW (ORCPT ); Mon, 30 Jun 2014 17:52:22 -0400 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.227]:59013 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754463AbaF3Vvq (ORCPT ); Mon, 30 Jun 2014 17:51:46 -0400 Message-Id: <20140630215145.055601726@goodmis.org> User-Agent: quilt/0.63-1 Date: Mon, 30 Jun 2014 17:50:42 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Oleg Nesterov , Namhyung Kim , Srikar Dronamraju , Masami Hiramatsu Subject: [for-next][PATCH 4/4] tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable() References: <20140630215038.852406012@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline; filename=0004-tracing-uprobes-Fix-the-usage-of-uprobe_buffer_enabl.patch X-RR-Connecting-IP: 107.14.168.118:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleg Nesterov 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(). Link: http://lkml.kernel.org/p/20140627170146.GA18332@redhat.com Acked-by: Namhyung Kim Acked-by: Srikar Dronamraju Reviewed-by: Masami Hiramatsu Fixes: dcad1a204f72 "tracing/uprobes: Fetch args before reserving a ring buffer" Signed-off-by: Oleg Nesterov Signed-off-by: Steven Rostedt --- kernel/trace/trace_uprobe.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index c4cf0abd60ba..3c9b97e6b1f4 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; } -- 2.0.0