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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 A6B82C43381 for ; Mon, 25 Feb 2019 13:54:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80D5920842 for ; Mon, 25 Feb 2019 13:54:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726787AbfBYNyf (ORCPT ); Mon, 25 Feb 2019 08:54:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49438 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725990AbfBYNye (ORCPT ); Mon, 25 Feb 2019 08:54:34 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 212748667D; Mon, 25 Feb 2019 13:54:34 +0000 (UTC) Received: from krava (unknown [10.43.17.18]) by smtp.corp.redhat.com (Postfix) with SMTP id 3C6AA5D9D1; Mon, 25 Feb 2019 13:54:32 +0000 (UTC) Date: Mon, 25 Feb 2019 14:54:30 +0100 From: Jiri Olsa To: Namhyung Kim Cc: Jonas Rabenstein , linux-perf-users , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , linux-kernel Subject: Re: [PATCH] perf hist: fix memory leak if histogram entry is reused Message-ID: <20190225135430.GD14757@krava> References: <20190221122306.1511-1-jonas.rabenstein@studium.uni-erlangen.de> <20190221123909.GG10990@krava> <20190221135320.io7egcwajehfrdd5@studium.uni-erlangen.de> <20190221162858.GA3940@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 25 Feb 2019 13:54:34 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 23, 2019 at 12:18:18PM +0900, Namhyung Kim wrote: > Hi, > > On Fri, Feb 22, 2019 at 1:29 AM Jiri Olsa wrote: > > > > On Thu, Feb 21, 2019 at 02:53:20PM +0100, Jonas Rabenstein wrote: > > > On Thu, Feb 21, 2019 at 01:39:09PM +0100, Jiri Olsa wrote: > > > > On Thu, Feb 21, 2019 at 01:23:06PM +0100, Jonas Rabenstein wrote: > > > > > In __hists__add_entry the srcline of the addr_location is duplicated > > > > > for the hist_entry. If hists__findnew_entry returns an already existing > > > > > hist_entry the srcline has to be freed again as no further reference to > > > > > that duplicated srcline would exists anymore. > > > > > > > > > > Signed-off-by: Jonas Rabenstein > > > > > --- > > > > > tools/perf/util/hist.c | 3 +++ > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c > > > > > index 8aad8330e392..25b8dbdbbe87 100644 > > > > > --- a/tools/perf/util/hist.c > > > > > +++ b/tools/perf/util/hist.c > > > > > @@ -623,6 +623,9 @@ __hists__add_entry(struct hists *hists, > > > > > .ops = ops, > > > > > }, *he = hists__findnew_entry(hists, &entry, al, sample_self); > > > > > > > > > > + if (he && he->srcline != entry.srcline) > > > > > + free(entry.srcline); > > > > > + > > > > > if (!hists->has_callchains && he && he->callchain_size != 0) > > > > > hists->has_callchains = true; > > > > > return he; > > > > > > > > nice, do we have similar issue in here? > > > > > > > > jirka > > > > > > > > > > > > --- > > > > diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c > > > > index 216388003dea..e65e6822c848 100644 > > > > --- a/tools/perf/util/hist.c > > > > +++ b/tools/perf/util/hist.c > > > > @@ -966,7 +966,7 @@ iter_add_next_cumulative_entry(struct hist_entry_iter *iter, > > > > .map = al->map, > > > > .sym = al->sym, > > > > }, > > > > - .srcline = al->srcline ? strdup(al->srcline) : NULL, > > > > + .srcline = al->srcline, > > > While this shouldn't leak the memory, we may end up with an al->srcline > > > to get free afterwards while still having a reference on it within the > > > hist_entry... Also I could not find where/how the hist_entry is freed up > > > so we may get an double free if both of al and he clean the srcline. > > > Of course, with your solution we could spare the useless strdup/free if > > > we find an hist_entry (which should be the typical case for hotspots..). > > > Taking a deeper look thus should be beneficial - but I do not have the > > > time for that right now because I'm still working on the inline-symbol > > > integration which is more important for me... > > > > ok, I'll check it > > I think we can defer calling strdup() to hist_entry__init(). right, thats actualy better fix even for the original patch, I'll try to post it soon thanks, jirka