From owner-freebsd-current@freebsd.org Tue Aug 27 13:03:59 2019 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id CCB11D5771 for ; Tue, 27 Aug 2019 13:03:59 +0000 (UTC) (envelope-from maksim.yevmenkin@gmail.com) Received: from mail-qk1-x736.google.com (mail-qk1-x736.google.com [IPv6:2607:f8b0:4864:20::736]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46HpwZ6Gfyz3MWb for ; Tue, 27 Aug 2019 13:03:58 +0000 (UTC) (envelope-from maksim.yevmenkin@gmail.com) Received: by mail-qk1-x736.google.com with SMTP id y22so971038qkb.11 for ; Tue, 27 Aug 2019 06:03:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LHxUrViDT12vb2WCrLNea15xvoa8Pot0kwYkG1kVRzk=; b=FN1YUVOEM+MO88doZo0HN98oj8o5wO+cVMoBRlX6/EESw+9Vj/nmT43vpjUQj5Q0cM 8E+DZimyWYBqsXT/UdYG4X/16qC7kY9GIT+GiFBOyjxqPrxTOX4qPrd9c2u9VBBBEx/d QnUMi3fTfIf49ZyP9wbmjWT2zgSo5Cr06D6jeeGrziFENSpKkx8/H4UQuELIyDSq+gWT VcCp+BQOKxmEGbz8muFG61iDtmXIZNKxylDGHoAVinYwYxF0QOmhkkNoHTDzvLAyTqxr 1IV7iLWFpCwp8lTIe2o8idgQpMaIE0BLPbdenXFPPWj+aPyLBWMm+DtHdt/xVfSPRrsQ t6jQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LHxUrViDT12vb2WCrLNea15xvoa8Pot0kwYkG1kVRzk=; b=LCSNpz5nzmLvXPSis6ZA/argszHMR9PX0Ydmve6gQ1sruMW66SMzL83yljKXMZLd4y dT2NMEutJ7udllZHi94vPUrF7MMx1ofitJhoqKqSaNgA0houP+czWEnlQiFQijWMjMHe M7vSJCtuov/9/wuY7HREwc7dHI5xzXf2seksEgUyyg/EY3T54Oy750omU3iZ1I/Wuu0E +vuzxSIe0yZQmtlDfGkWa6jSlkg9xpEOyo/2QG6tU48qBKu2LCPSSm4p3rM7zRx2EOzk Cwpdw3w51EihJ4iyMtlxncGJtUw+dot1PPcMP0XRKNRZ/Aoex4K7ikrv9uMlUTIJO+i+ +ESw== X-Gm-Message-State: APjAAAVvvQ3eHaPUltvEO5q6w2rQQwMnEg7yt/IjRoPU9kkEowkbjXNy c2Bol6KsdgLxsbZGyfuToMbYXi8QRFW0ZpSmQPA= X-Google-Smtp-Source: APXvYqy5DfojYNwmfPHytafUlEXzhaw3I57o3/og5XfoFAI62CtFigo9BF0OuyPAPYyP0y+Z0BXHFLzTAaTGHECtwWQ= X-Received: by 2002:a37:7cc:: with SMTP id 195mr4129435qkh.387.1566911037241; Tue, 27 Aug 2019 06:03:57 -0700 (PDT) MIME-Version: 1.0 References: <47509401.1440476.1566796167857.ref@mail.yahoo.com> <47509401.1440476.1566796167857@mail.yahoo.com> <5aa8faeb-5e8e-38be-4301-81f3d82c494a@selasky.org> <00E772F0-7231-44C4-B314-26730CC7DF21@gmail.com> <20190827071052.GT71821@kib.kiev.ua> <233039408.1857163.1566892977201@mail.yahoo.com> In-Reply-To: <233039408.1857163.1566892977201@mail.yahoo.com> From: Maksim Yevmenkin Date: Tue, 27 Aug 2019 06:03:46 -0700 Message-ID: Subject: Re: Kernel-Crash when working with ubt0 To: "mms.vanbreukelingen@gmail.com" Cc: "kostikbel@gmail.com" , Warner Losh , Hans Petter Selasky , "freebsd-current@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 46HpwZ6Gfyz3MWb X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=FN1YUVOE; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of maksimyevmenkin@gmail.com designates 2607:f8b0:4864:20::736 as permitted sender) smtp.mailfrom=maksimyevmenkin@gmail.com X-Spamd-Result: default: False [-4.00 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36:c]; FREEMAIL_FROM(0.00)[gmail.com]; RCPT_COUNT_FIVE(0.00)[5]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-1.00)[-0.997,0]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; TAGGED_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com.dwl.dnswl.org : 127.0.5.0]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; TAGGED_RCPT(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-current@freebsd.org]; MIME_GOOD(-0.10)[text/plain]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[6.3.7.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; IP_SCORE(0.00)[ip: (-9.37), ipnet: 2607:f8b0::/32(-2.86), asn: 15169(-2.33), country: US(-0.05)]; FREEMAIL_CC(0.00)[gmail.com]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Aug 2019 13:03:59 -0000 > > Hmm... interesting.... > > > > I only took a brief look at it. I suppose I can ensure user space address is wired and then copyout() can be called with mutex held > > >No, you cannot do this, at least without making the kernel to panic. > User might unmap the wired mapping at any time still. Kostik, i was thinking along the lines of vslock/vsunlock and copyout_nofault. basically similar to the sysctl code. do you think this would not work? thanks, max