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=-11.6 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 DD092C4727F for ; Thu, 1 Oct 2020 21:50:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A32272075F for ; Thu, 1 Oct 2020 21:50:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601589052; bh=vvAEf2Gi2d43VX0OLIxuwTV1L6w4EYfWAmQbzKPRMN4=; h=Subject:From:To:Cc:Date:In-Reply-To:References:List-ID:From; b=mtoGSMXqZBruULwBv1OeRY6qw7lrvOlmQ9OGj56SknkE53HV9HMgGM4l4KXG6vpKC PbIdaUOEgYSK/XAiNisezxS1yOVqEskKX7t5JwblHRBeGCLiGzmk6mJ9U/O8xyHuw8 Kp2rtwCT19Ksi8R5ixwsFoaqTAKZg3686imlj8wE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733218AbgJAVuv (ORCPT ); Thu, 1 Oct 2020 17:50:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:42654 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733191AbgJAVuv (ORCPT ); Thu, 1 Oct 2020 17:50:51 -0400 Received: from tzanussi-mobl (c-73-209-127-30.hsd1.il.comcast.net [73.209.127.30]) (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 7702F206A2; Thu, 1 Oct 2020 21:50:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601589050; bh=vvAEf2Gi2d43VX0OLIxuwTV1L6w4EYfWAmQbzKPRMN4=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=ZPW18z6jIBI4V2WKcUXKGGKZ3S+8gj+30rHpH1XgJ97db3vaMUMrfFL58RNvZnqKI GUi6Ti48cLeFR22/VSSHbKmrJRg5kQI9Nhx7WN+ccQ3rxo3TpOeA7uNK3omWzExsQn Cz8FI/zCiA4oI7kCSNiu+t25VSY2DATNJhENeVfA= Message-ID: <928fc2ba78e1319704c4ecdbf20d87c9f221ac6c.camel@kernel.org> Subject: Re: [PATCH v2 1/3] tracing: Change STR_VAR_MAX_LEN From: Tom Zanussi To: Axel Rasmussen Cc: Steven Rostedt , Masami Hiramatsu , LKML Date: Thu, 01 Oct 2020 16:50:49 -0500 In-Reply-To: References: <8616d1a2485fee1ae71d27d7c598acf1c9e32abe.1601490263.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 Wed, 2020-09-30 at 15:45 -0700, Axel Rasmussen wrote: > I still get the same WARN_ON behavior when trying to use bpftrace. > But, I spent some time today reading through that call path, and at > this point I'm convinced that it's the version of bpftrace I'm using > which is slightly broken, not the kernel in this case. (To be fair, > I'm trying to use some unreleased tip-of-tree version of it, with > some > not-yet-merged patches, and some extra hacks on top of all that, so > it's not particularly surprising...) > > In my experiments with just the synthetic event + histogram triggers, > this patchset works as expected for my use case. > > So (for the whole series, not just this one patch): > > Tested-by: Axel Rasmussen Thanks! Tom > > On Wed, Sep 30, 2020 at 11:41 AM Tom Zanussi > wrote: > > > > 32 is too small for this value, and anyway it makes more sense to > > use > > MAX_FILTER_STR_VAL, as this is also the value used for variable- > > length > > __strings. > > > > Signed-off-by: Tom Zanussi > > --- > > kernel/trace/trace_synth.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/trace/trace_synth.h > > b/kernel/trace/trace_synth.h > > index ac35c45207c4..5166705d1556 100644 > > --- a/kernel/trace/trace_synth.h > > +++ b/kernel/trace/trace_synth.h > > @@ -7,7 +7,7 @@ > > #define SYNTH_SYSTEM "synthetic" > > #define SYNTH_FIELDS_MAX 32 > > > > -#define STR_VAR_LEN_MAX 32 /* must be multiple of > > sizeof(u64) */ > > +#define STR_VAR_LEN_MAX MAX_FILTER_STR_VAL /* must > > be multiple of sizeof(u64) */ > > > > struct synth_field { > > char *type; > > -- > > 2.17.1 > >