From owner-svn-src-head@freebsd.org Thu Jun 15 05:12:33 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id DE4DDC09FD2 for ; Thu, 15 Jun 2017 05:12:33 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-it0-x22e.google.com (mail-it0-x22e.google.com [IPv6:2607:f8b0:4001:c0b::22e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A1B0464361 for ; Thu, 15 Jun 2017 05:12:33 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-it0-x22e.google.com with SMTP id l6so4314537iti.1 for ; Wed, 14 Jun 2017 22:12:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=JaWEY6jdsVSduE4nTczLzyABijljlGOSTn4E48zHL5c=; b=BGR0avJyxF5C4i1aPrh9jVxUGVLqBx4p4KkAuteZjeaaek2ZRckUUc6Mh0IiiaJ9Vo BwF7bVIsN+vaNp0WS5gxJU/LrEPvduuq6XPlJjFwGIfNe13dND80Q1O1VZDXtv+FsspI Zf9/tsWSTl5Fbs3Rs9vQVnjbgObyZrcTuG1TqMmUi+BH+Z1ARw85KG1YzaJweBgfmcyP BMtc3Uj8K4mkTaRFQJ30uQ7IFIL8wqMFF6qWAqin9uW010IV7DB/RCvFdy8Vb5frYukw x0Jz0HRJW28V24ghlUxRhHWPSfXuJg7ExFRN3JWYi0jciVYNkIiGvLT0qEov+zkzgjW5 mdqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=JaWEY6jdsVSduE4nTczLzyABijljlGOSTn4E48zHL5c=; b=NJre5Hslp/nvamabZujocrfmT8RpRoQ6K2gVfuBQ3oOfVsFMy/EMSMRnBli3L1+KgP 8VU2DscsVTbPh2IERPsEi0fUMeZm3yfx7A+y6xWqt9Ip5dXe8I+/18YA0EDvvSyml65p BrSEzGrmf7uLVJA5/HC+Emq+oYbdac/pE+Ep8bwZCpEpfn5nrnK9NUUYuz+ISUa3jLFc kNdMP5GDpapGJwxDwJHJTOvu84Vmo4S53PQ9j0k7gmpJD7zc+xHTzWZ5mwZxrhaaFS/4 jtyo9NZUzPQGBYfUoInRBPnrZzgVgfbfPTGu7e1JeEsd9GWqubUtpOkDdQ2M0VdIAU7Z bRuQ== X-Gm-Message-State: AKS2vOxyKjkY79+J/3UWDo6Qy0Nz5bTok0Md0Lq+kibWB6ExVTDG7sOl XEZuWc675EL1tV/Y3/O9GiGLIfgQSkxL X-Received: by 10.36.73.131 with SMTP id e3mr3539218itd.0.1497503552846; Wed, 14 Jun 2017 22:12:32 -0700 (PDT) MIME-Version: 1.0 Sender: wlosh@bsdimp.com Received: by 10.79.192.69 with HTTP; Wed, 14 Jun 2017 22:12:32 -0700 (PDT) X-Originating-IP: [2603:300b:6:5100:402:51b7:c887:1fa6] In-Reply-To: <20170615050400.GP50023@FreeBSD.org> References: <201706122111.v5CLBBUT092606@repo.freebsd.org> <20170612234356.GD50023@FreeBSD.org> <20170613120643.GX2088@kib.kiev.ua> <20170615050400.GP50023@FreeBSD.org> From: Warner Losh Date: Wed, 14 Jun 2017 23:12:32 -0600 X-Google-Sender-Auth: YDmV6edDimOk7ItQVBlhghD7Xfk Message-ID: Subject: Re: svn commit: r319874 - head/sys/kern To: Gleb Smirnoff Cc: Konstantin Belousov , src-committers , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.23 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jun 2017 05:12:34 -0000 On Wed, Jun 14, 2017 at 11:04 PM, Gleb Smirnoff wrote: > On Tue, Jun 13, 2017 at 03:06:43PM +0300, Konstantin Belousov wrote: > K> On Mon, Jun 12, 2017 at 04:43:56PM -0700, Gleb Smirnoff wrote: > K> > On Mon, Jun 12, 2017 at 09:11:11PM +0000, Konstantin Belousov wrote: > K> > K> Author: kib > K> > K> Date: Mon Jun 12 21:11:11 2017 > K> > K> New Revision: 319874 > K> > K> URL: https://svnweb.freebsd.org/changeset/base/319874 > K> > K> > K> > K> Log: > K> > K> Print unimplemented syscall number to the ctty on SIGSYS, if > enabled > K> > K> by the knob kern.lognosys. > K> > > K> > Why is it off by default? > K> In some (non-default) situation it may cause lot of ctty output. > K> I made the knob tunable to allow it to be set very early (init) > K> if needed. > > I remember myself being a beginner UNIX user, and all this > "bad system call, core dumped" messages were so annoyingly > uninformative for me, and I had no idea how to track to the > actual problem. This feature gives a lot of clue for a beginner > user, but having it default to off, devaluates its value. > We can also rate limit the messages. We have the technology. Warner > > To avoid possible tty spam for an application that produces ton > of bad syscalls, but ignores SIGSYS, we can enable the feature > for those processes, who doesn't ignore SIGSYS. > > -- > Totus tuus, Glebius. > >