Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755898AbaF3REQ (ORCPT ); Mon, 30 Jun 2014 13:04:16 -0400 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:57618 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752643AbaF3REP (ORCPT ); Mon, 30 Jun 2014 13:04:15 -0400 Date: Mon, 30 Jun 2014 22:34:09 +0530 From: Srikar Dronamraju To: Oleg Nesterov Cc: Steven Rostedt , Masami Hiramatsu , Namhyung Kim , 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() Message-ID: <20140630170409.GD5619@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20140627170116.GA18298@redhat.com> <20140627170146.GA18332@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20140627170146.GA18332@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14063017-8878-0000-0000-00000D4100B9 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 Acked-by: Srikar Dronamraju (one nit .. ) > + 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(); > + How about avoiding err_buffer label? + if (!ret) + return 0; + uprobe_buffer_disable(); + > + err_flags: > + if (file) { > + list_del(&link->list); > > -- > 1.5.5.1 > -- Thanks and Regards Srikar Dronamraju -- 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/