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 4F02EC10F0E for ; Tue, 9 Apr 2019 14:54:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20F8420674 for ; Tue, 9 Apr 2019 14:54:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726471AbfDIOy1 (ORCPT ); Tue, 9 Apr 2019 10:54:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:6853 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726401AbfDIOy1 (ORCPT ); Tue, 9 Apr 2019 10:54:27 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 502048B13F; Tue, 9 Apr 2019 14:54:27 +0000 (UTC) Received: from sandy.ghostprotocols.net (ovpn-112-34.phx2.redhat.com [10.3.112.34]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CD4DE19C7F; Tue, 9 Apr 2019 14:54:26 +0000 (UTC) Received: by sandy.ghostprotocols.net (Postfix, from userid 1000) id DD6345B81; Tue, 9 Apr 2019 11:54:23 -0300 (BRT) Date: Tue, 9 Apr 2019 11:54:23 -0300 From: Arnaldo Carvalho de Melo To: Steven Rostedt Cc: Rikard Falkeborn , linux-kernel@vger.kernel.org, tstoyanov@vmware.com, Linux Trace Devel Subject: Re: [PATCH] tools lib traceevent: Fix missing equality check for strcmp Message-ID: <20190409145423.GD2581@redhat.com> References: <20190409091529.2686-1-rikard.falkeborn@gmail.com> <20190409092122.2e8f62f0@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190409092122.2e8f62f0@gandalf.local.home> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.20 (2009-12-10) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 09 Apr 2019 14:54:27 +0000 (UTC) Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org Em Tue, Apr 09, 2019 at 09:21:22AM -0400, Steven Rostedt escreveu: > > Hi Rikard, > > On Tue, 9 Apr 2019 11:15:29 +0200 > Rikard Falkeborn wrote: > > > There was a missing comparison with 0 when checking if type is "s64" or > > "u64". Therefore, the body of the if-statement was entered if "type" was > > "u64" or not "s64", which made the first strcmp() redundant since if > > type is "u64", it's not "s64". > > > > If type is "s64", the body of the if-statement is not entered but since the > > remainder of the function consists of if-statements which will not be > > entered if type is "s64", we will just return "val", which is correct, > > albeit at the cost of a few more calls to strcmp(), i.e., it will behave > > just as if the if-statement was entered. > > > > If type is neither "s64" or "u64", the body of the if-statement will be > > entered incorrectly and "val" returned. This means that any type that is > > checked after "s64" and "u64" is handled the same way as "s64" and > > "u64", i.e., the limiting of "val" to fit in for example "s8" is never > > reached. > > > > This was introduced in the kernel tree when the sources were copied from > > trace-cmd in commit f7d82350e597 ("tools/events: Add files to create > > libtraceevent.a"), and in the trace-cmd repo in 1cdbae6035cei ("Implement > > typecasting in parser") when the function was introduced, i.e., it has > > always behaved the wrong way. > > > > Detected by cppcheck. > > Nice. Thanks for this. > > > > > Fixes: f7d82350e597 ("tools/events: Add files to create libtraceevent.a") > > Signed-off-by: Rikard Falkeborn > > Reviewed-by: Steven Rostedt (VMware) > > Arnaldo, > > Care to pull this in? Sure, thanks. - Arnaldo > Thanks! > > -- Steve > > > --- > > I have only compile tested the patch but it should be correct. I don't > > know if any other problems will surface due to this though. > > --- > > tools/lib/traceevent/event-parse.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > > index 87494c7c619d..981c6ce2da2c 100644 > > --- a/tools/lib/traceevent/event-parse.c > > +++ b/tools/lib/traceevent/event-parse.c > > @@ -2233,7 +2233,7 @@ eval_type_str(unsigned long long val, const char *type, int pointer) > > return val & 0xffffffff; > > > > if (strcmp(type, "u64") == 0 || > > - strcmp(type, "s64")) > > + strcmp(type, "s64") == 0) > > return val; > > > > if (strcmp(type, "s8") == 0)