Received: by 10.192.165.156 with SMTP id m28csp639057imm; Wed, 11 Apr 2018 05:08:48 -0700 (PDT) X-Google-Smtp-Source: AIpwx49fQupYsDkhrHyi2Vug1tsgITaTUIFmyu+7QXX9/W3tomTih0QLYUPUKS//tferdWsu99Ou X-Received: by 10.101.66.70 with SMTP id d6mr3262128pgq.234.1523448528546; Wed, 11 Apr 2018 05:08:48 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1523448528; cv=none; d=google.com; s=arc-20160816; b=jbqWbCjmex5euvZEehcYwkf9wZJihf+nHf8wPF9QbkOgGiHxiAEQSASl4v9q5Ke1is n+BsrCPwyTD47frJSeP1NcTs/VZOLAi2DiqzDvlA8KF4dn37CT+9Nr5f6eZt2FpafVyJ U8Gsp98Yh7J2oJO4D4XF0EImKXrPNLF+yFsLqRmzsvG2OIMCBSJIviq1EG0yduF5PyPB bGhOPI/jYnNbQ177WNP3VEB/g9APS2Nt/9PkHTVVGYEqUPE2xJ5wSh9o4P8a8ZtFW6es ZQSFlv44kMTQVkYtFv4D4iFRtoCcMTtcTZFS6ETCM7LbzMXan1tv+L13PPDh58lDV1nr lPfw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature:arc-authentication-results; bh=gcy0Bxs6zKkt4B2F7jdD9NTqupkYz7rnUhLJCqhC168=; b=0y5i7qs1aBAobcJuQFB/eaYIbqVxzBhcLcGytOEmLR29QpNDFgRUWw3UMDl1+ytnb5 E9F6V/fHzsiwdFFNufiesyNuoMANVWS9/idTrXtd1J/9RfhggfyVlf1Shu0w7CDDRrxo rWiCrfN92fkXgxYjXVwMk+1UTOx/zGrPOm+idU/kBGfMw/XpfGhKxUxKjbTmNCu7cwhB 3xI9+eJ5uWDDSEoTb/fwnM1jqnR55EJBmQv98iBpBLZbTI6cdOWTriu9qgfXCp7QLSqU og1PUxYbTEIuuEMQF2maTCTVWT0faA0w0p5pKY314BNnGFzwtvbWsYKaYm3m9bAFvs6E BZvQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=VDOJgdwU; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id s3-v6si974672plb.418.2018.04.11.05.08.11; Wed, 11 Apr 2018 05:08:48 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=VDOJgdwU; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753070AbeDKMEw (ORCPT + 99 others); Wed, 11 Apr 2018 08:04:52 -0400 Received: from mail-wm0-f53.google.com ([74.125.82.53]:35347 "EHLO mail-wm0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753041AbeDKMEv (ORCPT ); Wed, 11 Apr 2018 08:04:51 -0400 Received: by mail-wm0-f53.google.com with SMTP id r82so3377628wme.0 for ; Wed, 11 Apr 2018 05:04:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=gcy0Bxs6zKkt4B2F7jdD9NTqupkYz7rnUhLJCqhC168=; b=VDOJgdwUmP4yIYyxR+Newd0/WmsIfb2R/Ig1V2HO2M6zvkkI6lzabx2JUVwm9Ta+eb Wmtuqm4jPIUtQO1pDW1VFTTrDvrjYxwbwybGU5OgVVLVqitE+mBCXnVyKSfbGvBYfBQY KbM++zsSQ3Uk4WuWNR7ZACegpT7s9WcCqOo9XsFZew+KF0Rk7VjKFfKl1zDlcrxpBZeF m8zOlQh0CH1IO0RgBzHAGO8dd8d/qI2KL7ZYEwNTe+U79oIHiNIL33riAGtGPrFg508t AKITQx7YVSnC9QlvRdXntzW2lg48sv2iGQUdsfGaSfMMJrnWB1Jbd4l/odNx5eGL5m07 S78Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=gcy0Bxs6zKkt4B2F7jdD9NTqupkYz7rnUhLJCqhC168=; b=i+ihG9HZFD9AehIdnj1QDbgi/xAwkOUhDwBOTejn266CIRyy+f6mTkxQej2R4pEjK8 tD583w/VuNJ78U/aLrlQch2V0WBcmPrriV4LWS1PJECSXWjZjZ4zme+fJswsbVpI0Enu 6+1EcTqHDSWISDWZFf2ynBIkOxB847CFvvZ2eF3QhocW+WgvwPNLhYFQs7Lz7N3hMm9r 8mqwiWJwvAk6Gw1507yYl1so2pkgE9EFiUOQXmApuY6vzwjGa38QwnodK+3zOy3trAsK kzan3+YeeoKbzfSjafwzj4iPbJhsc1rrJCXZ0en5mWgTBiGKi3ZMXCMDTromexipGNWu 6QUA== X-Gm-Message-State: ALQs6tB5uCPUaek/TFtsbszvs9qEXfHZusTEW0lltoMtkLryxx5xtSFg U/b7/UHfGiEkgVzHYGRjVpQ= X-Received: by 10.28.129.86 with SMTP id c83mr2350335wmd.37.1523448290068; Wed, 11 Apr 2018 05:04:50 -0700 (PDT) Received: from gmail.com (2E8B0CD5.catv.pool.telekom.hu. [46.139.12.213]) by smtp.gmail.com with ESMTPSA id g185sm2897730wmf.40.2018.04.11.05.04.49 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 11 Apr 2018 05:04:49 -0700 (PDT) Date: Wed, 11 Apr 2018 14:04:47 +0200 From: Ingo Molnar To: Song Liu Cc: Vince Weaver , "linux-kernel@vger.kernel.org" , Peter Zijlstra Subject: Re: perf: fuzzer leads to trace_kprobe: Could not insert message flood Message-ID: <20180411120447.2gzrwijrtayjv3eg@gmail.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Song Liu wrote: > > > > On Apr 10, 2018, at 7:48 AM, Vince Weaver wrote: > > > > Author: Song Liu > > Date: Wed Dec 6 14:45:15 2017 -0800 > > > > When running the perf_fuzzer on a current git checkout my logs are flooded > > with messages such as this: > > [71487.869077] trace_kprobe: Could not insert probe at unknown+0: -22 > > [71488.174479] trace_kprobe: Could not insert probe at unknown+0: -22 > > > > Presumably this is due to the introduction of the perf_kprobe PMU in > > commit e12f03d7031a977356e3d7b75a68c2185ff8d155 > > Author: Song Liu > > Date: Wed Dec 6 14:45:15 2017 -0800 > > > > Is there a way to get this error disabled, or else rate-limited? > > > > Vince > > Hi Vince, > > Thanks for the report. > > This is a new API that creates probe together with perf_event_open(). Based on > my limited understanding of perf_fuzzer, it doesn't understand this API, and uses > it in an abnormal way. [...] Vince's point is valid: the kernel log should not be flooded with pointless messages as a response to user-space ABI uses ... Why is there a kernel log message at all, isn't an error returned? > [...] I would recommend perf_fuzzer to understand this new API and test it. > [...] This bug needs to be fixed: a new API must not effectively DoS fuzzing efforts by spamming the kernel log ... Thanks, Ingo