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=-12.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 045B4C4741F for ; Wed, 30 Sep 2020 18:40:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E9E220848 for ; Wed, 30 Sep 2020 18:40:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601491243; bh=Nw45fjTRE6xb20gbtpxGUyzJM+N++BLrf5o52RUDaZQ=; h=Subject:From:To:Cc:Date:In-Reply-To:References:List-ID:From; b=enLglRGHBSPXeZenzcMtoCl43UJw8s9uOy8ivX1FlVZAUJJlYqxtZk8ad+6Xh4NiK 4EhnKHxKvGUH9mO/SmIdAQyP2oH7/3+wFCv76hkLwFRupnUJP7TC5vaOrgyWdXnt6K Fq/PUzNBYFAPxU1/medSmgaq5cXgigRQhxGcyIk8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729840AbgI3Skm (ORCPT ); Wed, 30 Sep 2020 14:40:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:50048 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726476AbgI3Skm (ORCPT ); Wed, 30 Sep 2020 14:40:42 -0400 Received: from tzanussi-mobl (c-98-220-232-140.hsd1.il.comcast.net [98.220.232.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 30FE020708; Wed, 30 Sep 2020 18:40:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601491241; bh=Nw45fjTRE6xb20gbtpxGUyzJM+N++BLrf5o52RUDaZQ=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=a69fToStglxxjDs+cTAw2R0aCprljyGox26FvJX2OqeppzWp0pg9RnqhOmbvIa3sU EGYj4xXw0qE6/6ZtyOB9YAB/pRjTBHDJV3G6stb8TBGALl6z+Ydx3GyBFnQRHdM2B2 8EXuV1mWXNHOUYSRwUJKT+HRvNVTc8IzxaAyyQdY= Message-ID: <832ee35903df56214b864e8042f24c7358a99668.camel@kernel.org> Subject: Re: [PATCH 2/3] tracing: Fix parse_synth_field() error handling From: Tom Zanussi To: Axel Rasmussen Cc: Steven Rostedt , Masami Hiramatsu , LKML Date: Wed, 30 Sep 2020 13:40:39 -0500 In-Reply-To: References: <834e9060c2e7e3272e25d8bfc6e7566639c18aa9.1601410890.git.zanussi@kernel.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Axel, On Tue, 2020-09-29 at 14:56 -0700, Axel Rasmussen wrote: > On Tue, Sep 29, 2020 at 1:33 PM Tom Zanussi > wrote: > > > > synth_field_size() returns either the size or an error. However, > > the > > code assigns the return val to ssize_t which is unsigned, and then > > tests whether it's less than 0, which it isn't so discards the > > error. > > I think the patch is correct, but the commit message is not. > field->size is a size_t (unsigned), not an ssize_t (signed). I think > this should say instead something like: > > synth_field_size() returns either a positive size or an error (zero > or > a negative value). However, the existing code assumes the only error > value is 0. It doesn't handle negative error codes, as it assigns > directly to field->size (a size_t; unsigned), thereby interpreting > the > error code as a valid size instead. > Yes, that's better - I used the above text in v2. > > > > Do the test before assignment to field->size. > > > > Signed-off-by: Tom Zanussi > > --- > > kernel/trace/trace_events_synth.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/trace/trace_events_synth.c > > b/kernel/trace/trace_events_synth.c > > index a9cd7793f7ea..6e7282c7b530 100644 > > --- a/kernel/trace/trace_events_synth.c > > +++ b/kernel/trace/trace_events_synth.c > > @@ -465,6 +465,7 @@ static struct synth_field > > *parse_synth_field(int argc, const char **argv, > > struct synth_field *field; > > const char *prefix = NULL, *field_type = argv[0], > > *field_name, *array; > > int len, ret = 0; > > + int size; > > Why not make this an ssize_t Yep, makes sense. Changed in v2, thanks! Tom > > > > > if (field_type[0] == ';') > > field_type++; > > @@ -520,11 +521,12 @@ static struct synth_field > > *parse_synth_field(int argc, const char **argv, > > field->type[len - 1] = '\0'; > > } > > > > - field->size = synth_field_size(field->type); > > - if (!field->size) { > > + size = synth_field_size(field->type); > > + if (size < 0) { > > ret = -EINVAL; > > goto free; > > } > > + field->size = size; > > > > if (synth_field_is_string(field->type)) > > field->is_string = true; > > -- > > 2.17.1 > >