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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B82A2C43334 for ; Tue, 19 Jul 2022 10:46:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234156AbiGSKqI (ORCPT ); Tue, 19 Jul 2022 06:46:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230483AbiGSKqG (ORCPT ); Tue, 19 Jul 2022 06:46:06 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F0D5637B for ; Tue, 19 Jul 2022 03:46:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658227563; x=1689763563; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=wFZZuEAnMChHcl1zG98D2Cn/4RFaJhpOx2El5z8ssBU=; b=SxAMH7U4q/b9tlumgFSfpHRCi7A7CE0iHUOKaXiE+uYTIz53NbSsmiK/ 6hCCg6m3naQyAj2l+Mg71Z2Ik53G8pwXO/nWzP5kBMmQnUP2mNICkHIAJ x0xN35sWa1Qf4csb4rjAInTbRAFaEUVljrw1ZTK1mBRfF+85tvwNIZ07P oP8wzvYT7cLG649IjBgQy5snp5glOCewVPMouJLRsCkJgBE9m98qOuMKp ndrYYFbYKTLMaMsm+aU5XdMydEWmR1NXtawaN/RHajRQeaup/cwbDwomg oLW0sbToqy0thOMd1rWsBA3nQYdoaJNP4ObhwGO08oVw1/xiRqSl480zs Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10412"; a="285212172" X-IronPort-AV: E=Sophos;i="5.92,283,1650956400"; d="scan'208";a="285212172" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2022 03:46:03 -0700 X-IronPort-AV: E=Sophos;i="5.92,283,1650956400"; d="scan'208";a="572803002" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO [10.0.2.15]) ([10.252.41.111]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2022 03:46:01 -0700 Message-ID: <5d7c9f8a-76f7-7c77-62a3-f94adc083497@intel.com> Date: Tue, 19 Jul 2022 13:45:56 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.11.0 Subject: Re: [PATCH 1/2] perf parse-events: Fix segfault when event parser gets an error Content-Language: en-US To: Ian Rogers Cc: Arnaldo Carvalho de Melo , Jiri Olsa , Namhyung Kim , linux-kernel@vger.kernel.org References: <20220712112824.28770-1-adrian.hunter@intel.com> <20220712112824.28770-2-adrian.hunter@intel.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/07/22 04:10, Ian Rogers wrote: > On Tue, Jul 12, 2022 at 4:28 AM Adrian Hunter wrote: >> >> parse_events() is often called with parse_events_error set to NULL. >> Make parse_events_error__handle() not segfault in that case. >> >> Fixes: 43eb05d06679 ("perf tests: Support 'Track with sched_switch' test for hybrid") >> Signed-off-by: Adrian Hunter >> --- >> tools/perf/util/parse-events.c | 14 +++++++++++--- >> 1 file changed, 11 insertions(+), 3 deletions(-) >> >> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c >> index 7ed235740431..700c95eafd62 100644 >> --- a/tools/perf/util/parse-events.c >> +++ b/tools/perf/util/parse-events.c >> @@ -2391,9 +2391,12 @@ void parse_events_error__exit(struct parse_events_error *err) >> void parse_events_error__handle(struct parse_events_error *err, int idx, >> char *str, char *help) >> { >> - if (WARN(!str, "WARNING: failed to provide error string\n")) { >> - free(help); >> - return; >> + if (WARN(!str, "WARNING: failed to provide error string\n")) >> + goto out_free; >> + if (!err) { >> + /* Assume caller does not want message printed */ >> + pr_debug("event syntax error: %s\n", str); >> + goto out_free; > > > It feels like a simpler invariant (as done elsewhere) to have the > caller always pass err and then in the caller to call > parse_events_error__exit. Any reason for behavior change? This is a bug fix. More complicated changes can be done separately, if desired, but it is wrong to segfault here in any case. > > Thanks, > Ian > >> } >> switch (err->num_errors) { >> case 0: >> @@ -2419,6 +2422,11 @@ void parse_events_error__handle(struct parse_events_error *err, int idx, >> break; >> } >> err->num_errors++; >> + return; >> + >> +out_free: >> + free(str); >> + free(help); >> } >> >> #define MAX_WIDTH 1000 >> -- >> 2.25.1 >>