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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D415C4332F for ; Tue, 8 Mar 2022 09:15:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345285AbiCHJQa (ORCPT ); Tue, 8 Mar 2022 04:16:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42930 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233068AbiCHJQ2 (ORCPT ); Tue, 8 Mar 2022 04:16:28 -0500 Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D48A40A16 for ; Tue, 8 Mar 2022 01:15:31 -0800 (PST) Received: by mail-wr1-x42c.google.com with SMTP id r10so27414552wrp.3 for ; Tue, 08 Mar 2022 01:15:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=A67AlhskYiiSCgOgMfxOM8VtIq/AZbd8NuTpwj7+O9E=; b=ru0ZMHr+H3SzWxJ5c6z+akoloC2eYUtrZZDP/bO0aM7LsTlONsVtFwFb/M0zFfOyf8 ElYyllP0vUy0v0lbdXhcPYe4WzX7ped6as7iO4g3cCmAJaWF+VZOQBy9ug42T440YpRF GUNi+yilLEuh339WAnK2G0QLo/WGwWiiz6vZ/8lCD4bCmK0TFsJdNrkLS30iJ3WFSL83 SnRbArDjmbspkK6+UFofwFDjTRmpVBG0W/hwgBdGn/4koeWXQAPzHE106Pho9SQPGPFW 5I7zM7fAiaC+9DyvnsQWd0h5V5zBpL4P1Hkpp1YpcllRm9Tk5tHYCkPE7/0BSdXqV9ip lg1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=A67AlhskYiiSCgOgMfxOM8VtIq/AZbd8NuTpwj7+O9E=; b=WU4wqvA87V1RfDJODQsbTAvCEQ+MaZM9rCd+0PrbWYMLucfLPJI+SW422FLSgCmeEf RmPV/kLFJcl1a3feHxtoRGAm0LGUUGiKtMuutCxH54WuleGr1P51UdlexxZhXLcKgPyj 4wZQaSpp9yKgtxamel9Cv7V6gvyR4Q5BWOXnnLWXwGFIoKyBjQwMNIacWt8jRrjR/gGF qV+aU3j2Rl0trII5zZsQriN9S2UvYI3rouG8xSBP98at4zB64mPq3sGe2mXwNaJklm/l EwXb3drYajBQ9VQcouiBa7uaRPVr5fOAOy81VLBWvAsRCzICQJ8GgWkeequq2KNt4uVA tXXA== X-Gm-Message-State: AOAM532wrXEuPV7YS81sX7ZUF0JeD6S2eigsfsGR7B4P+NTqVDLPb8B1 BSP21pbZR2zLpInI2mZwRJeXhQ== X-Google-Smtp-Source: ABdhPJy9FjH8HkL7B/j6ELLmslkDBEpsnA6isr76dWseTv/sIBWInh7Ka7q7NHwbZ1Go3z4nK7Q0BQ== X-Received: by 2002:adf:e448:0:b0:1ea:c7b6:782 with SMTP id t8-20020adfe448000000b001eac7b60782mr11302842wrm.29.1646730930092; Tue, 08 Mar 2022 01:15:30 -0800 (PST) Received: from google.com (cpc155339-bagu17-2-0-cust87.1-3.cable.virginm.net. [86.27.177.88]) by smtp.gmail.com with ESMTPSA id h13-20020adff18d000000b001f1de9f930esm15425518wro.81.2022.03.08.01.15.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 01:15:29 -0800 (PST) Date: Tue, 8 Mar 2022 09:15:27 +0000 From: Lee Jones To: Greg KH Cc: mst@redhat.com, jasowang@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, stable@vger.kernel.org, syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com Subject: Re: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Message-ID: References: <20220307191757.3177139-1-lee.jones@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 08 Mar 2022, Greg KH wrote: > On Tue, Mar 08, 2022 at 08:10:06AM +0000, Lee Jones wrote: > > On Mon, 07 Mar 2022, Greg KH wrote: > > > > > On Mon, Mar 07, 2022 at 07:17:57PM +0000, Lee Jones wrote: > > > > vhost_vsock_handle_tx_kick() already holds the mutex during its call > > > > to vhost_get_vq_desc(). All we have to do here is take the same lock > > > > during virtqueue clean-up and we mitigate the reported issues. > > > > > > > > Also WARN() as a precautionary measure. The purpose of this is to > > > > capture possible future race conditions which may pop up over time. > > > > > > > > Link: https://syzkaller.appspot.com/bug?extid=279432d30d825e63ba00 > > > > > > > > Cc: > > > > Reported-by: syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com > > > > Signed-off-by: Lee Jones > > > > --- > > > > drivers/vhost/vhost.c | 10 ++++++++++ > > > > 1 file changed, 10 insertions(+) > > > > > > > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > > > > index 59edb5a1ffe28..ef7e371e3e649 100644 > > > > --- a/drivers/vhost/vhost.c > > > > +++ b/drivers/vhost/vhost.c > > > > @@ -693,6 +693,15 @@ void vhost_dev_cleanup(struct vhost_dev *dev) > > > > int i; > > > > > > > > for (i = 0; i < dev->nvqs; ++i) { > > > > + /* No workers should run here by design. However, races have > > > > + * previously occurred where drivers have been unable to flush > > > > + * all work properly prior to clean-up. Without a successful > > > > + * flush the guest will malfunction, but avoiding host memory > > > > + * corruption in those cases does seem preferable. > > > > + */ > > > > + WARN_ON(mutex_is_locked(&dev->vqs[i]->mutex)); > > > > > > So you are trading one syzbot triggered issue for another one in the > > > future? :) > > > > > > If this ever can happen, handle it, but don't log it with a WARN_ON() as > > > that will trigger the panic-on-warn boxes, as well as syzbot. Unless > > > you want that to happen? > > > > No, Syzbot doesn't report warnings, only BUGs and memory corruption. > > Has it changed? Last I looked, it did trigger on WARN_* calls, which > has resulted in a huge number of kernel fixes because of that. Everything is customisable in syzkaller, so maybe there are specific builds which panic_on_warn enabled, but none that I'm involved with do. Here follows a topical example. The report above in the Link: tag comes with a crashlog [0]. In there you can see the WARN() at the bottom of vhost_dev_cleanup() trigger many times due to a populated (non-flushed) worker list, before finally tripping the BUG() which triggers the report: [0] https://syzkaller.appspot.com/text?tag=CrashLog&x=16a61fce700000 > > > And what happens if the mutex is locked _RIGHT_ after you checked it? > > > You still have a race... > > > > No, we miss a warning that one time. Memory is still protected. > > Then don't warn on something that doesn't matter. This line can be > dropped as there's nothing anyone can do about it, right? You'll have to take that point up with Michael. -- Lee Jones [李琼斯] Principal Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog 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 Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1305AC433F5 for ; Tue, 8 Mar 2022 09:15:37 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id AEA27400FF; Tue, 8 Mar 2022 09:15:36 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id N3VtedchTKik; Tue, 8 Mar 2022 09:15:35 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTPS id E8531408E2; Tue, 8 Mar 2022 09:15:34 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id BD0EEC0012; Tue, 8 Mar 2022 09:15:34 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4E576C000B for ; Tue, 8 Mar 2022 09:15:33 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 363D884155 for ; Tue, 8 Mar 2022 09:15:33 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp1.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=linaro.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id EF-0_356-VeJ for ; Tue, 8 Mar 2022 09:15:32 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-wr1-x433.google.com (mail-wr1-x433.google.com [IPv6:2a00:1450:4864:20::433]) by smtp1.osuosl.org (Postfix) with ESMTPS id ECCD68414C for ; Tue, 8 Mar 2022 09:15:31 +0000 (UTC) Received: by mail-wr1-x433.google.com with SMTP id i8so27363825wrr.8 for ; Tue, 08 Mar 2022 01:15:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=A67AlhskYiiSCgOgMfxOM8VtIq/AZbd8NuTpwj7+O9E=; b=ru0ZMHr+H3SzWxJ5c6z+akoloC2eYUtrZZDP/bO0aM7LsTlONsVtFwFb/M0zFfOyf8 ElYyllP0vUy0v0lbdXhcPYe4WzX7ped6as7iO4g3cCmAJaWF+VZOQBy9ug42T440YpRF GUNi+yilLEuh339WAnK2G0QLo/WGwWiiz6vZ/8lCD4bCmK0TFsJdNrkLS30iJ3WFSL83 SnRbArDjmbspkK6+UFofwFDjTRmpVBG0W/hwgBdGn/4koeWXQAPzHE106Pho9SQPGPFW 5I7zM7fAiaC+9DyvnsQWd0h5V5zBpL4P1Hkpp1YpcllRm9Tk5tHYCkPE7/0BSdXqV9ip lg1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=A67AlhskYiiSCgOgMfxOM8VtIq/AZbd8NuTpwj7+O9E=; b=GFKbHP0S3+GvIZuEjtn3bKHyXTm44VFMs6lR2jyubRUJbkVZeY24xM2JOQn+yl9cx0 pCoLiCPC8bBM7YK5XFg+9UWvLqXjYP43u77B+/mvWQivdw8qNYCNH3CGKkiq/abjBkMw J159QXMg+HgFTFgprwapf5nRZvWtU9Yco2vBoAJctb/k9wZ407auSW6s+aEIs52KAM7p JfLhPI0Nt9bRUDmVumTpwTHY5R5RNfHM6sC8hztIajMPIggMLHu66yaD7NNTsLs51Uuh BdIjoaHElh1bpCStGP2jpn61t+4vRe8kzHHmBAsc3a4ddC1U19XYwhqxFzQ4JSdUqSgs q7cg== X-Gm-Message-State: AOAM533xjyOpje83Gqg7SBpEqhDWDbXDf0QwXT5SwbTxyR04s3VL7GAu M9pjOHLKh1F9CMbiOE4h8Pl1yA== X-Google-Smtp-Source: ABdhPJy9FjH8HkL7B/j6ELLmslkDBEpsnA6isr76dWseTv/sIBWInh7Ka7q7NHwbZ1Go3z4nK7Q0BQ== X-Received: by 2002:adf:e448:0:b0:1ea:c7b6:782 with SMTP id t8-20020adfe448000000b001eac7b60782mr11302842wrm.29.1646730930092; Tue, 08 Mar 2022 01:15:30 -0800 (PST) Received: from google.com (cpc155339-bagu17-2-0-cust87.1-3.cable.virginm.net. [86.27.177.88]) by smtp.gmail.com with ESMTPSA id h13-20020adff18d000000b001f1de9f930esm15425518wro.81.2022.03.08.01.15.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 01:15:29 -0800 (PST) Date: Tue, 8 Mar 2022 09:15:27 +0000 From: Lee Jones To: Greg KH Subject: Re: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Message-ID: References: <20220307191757.3177139-1-lee.jones@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Cc: syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com, kvm@vger.kernel.org, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, virtualization@lists.linux-foundation.org X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" T24gVHVlLCAwOCBNYXIgMjAyMiwgR3JlZyBLSCB3cm90ZToKCj4gT24gVHVlLCBNYXIgMDgsIDIw MjIgYXQgMDg6MTA6MDZBTSArMDAwMCwgTGVlIEpvbmVzIHdyb3RlOgo+ID4gT24gTW9uLCAwNyBN YXIgMjAyMiwgR3JlZyBLSCB3cm90ZToKPiA+IAo+ID4gPiBPbiBNb24sIE1hciAwNywgMjAyMiBh dCAwNzoxNzo1N1BNICswMDAwLCBMZWUgSm9uZXMgd3JvdGU6Cj4gPiA+ID4gdmhvc3RfdnNvY2tf aGFuZGxlX3R4X2tpY2soKSBhbHJlYWR5IGhvbGRzIHRoZSBtdXRleCBkdXJpbmcgaXRzIGNhbGwK PiA+ID4gPiB0byB2aG9zdF9nZXRfdnFfZGVzYygpLiAgQWxsIHdlIGhhdmUgdG8gZG8gaGVyZSBp cyB0YWtlIHRoZSBzYW1lIGxvY2sKPiA+ID4gPiBkdXJpbmcgdmlydHF1ZXVlIGNsZWFuLXVwIGFu ZCB3ZSBtaXRpZ2F0ZSB0aGUgcmVwb3J0ZWQgaXNzdWVzLgo+ID4gPiA+IAo+ID4gPiA+IEFsc28g V0FSTigpIGFzIGEgcHJlY2F1dGlvbmFyeSBtZWFzdXJlLiAgVGhlIHB1cnBvc2Ugb2YgdGhpcyBp cyB0bwo+ID4gPiA+IGNhcHR1cmUgcG9zc2libGUgZnV0dXJlIHJhY2UgY29uZGl0aW9ucyB3aGlj aCBtYXkgcG9wIHVwIG92ZXIgdGltZS4KPiA+ID4gPiAKPiA+ID4gPiBMaW5rOiBodHRwczovL3N5 emthbGxlci5hcHBzcG90LmNvbS9idWc/ZXh0aWQ9Mjc5NDMyZDMwZDgyNWU2M2JhMDAKPiA+ID4g PiAKPiA+ID4gPiBDYzogPHN0YWJsZUB2Z2VyLmtlcm5lbC5vcmc+Cj4gPiA+ID4gUmVwb3J0ZWQt Ynk6IHN5emJvdCthZGMzY2IzMjM4NTU4NmJlYzg1OUBzeXprYWxsZXIuYXBwc3BvdG1haWwuY29t Cj4gPiA+ID4gU2lnbmVkLW9mZi1ieTogTGVlIEpvbmVzIDxsZWUuam9uZXNAbGluYXJvLm9yZz4K PiA+ID4gPiAtLS0KPiA+ID4gPiAgZHJpdmVycy92aG9zdC92aG9zdC5jIHwgMTAgKysrKysrKysr Kwo+ID4gPiA+ICAxIGZpbGUgY2hhbmdlZCwgMTAgaW5zZXJ0aW9ucygrKQo+ID4gPiA+IAo+ID4g PiA+IGRpZmYgLS1naXQgYS9kcml2ZXJzL3Zob3N0L3Zob3N0LmMgYi9kcml2ZXJzL3Zob3N0L3Zo b3N0LmMKPiA+ID4gPiBpbmRleCA1OWVkYjVhMWZmZTI4Li5lZjdlMzcxZTNlNjQ5IDEwMDY0NAo+ ID4gPiA+IC0tLSBhL2RyaXZlcnMvdmhvc3Qvdmhvc3QuYwo+ID4gPiA+ICsrKyBiL2RyaXZlcnMv dmhvc3Qvdmhvc3QuYwo+ID4gPiA+IEBAIC02OTMsNiArNjkzLDE1IEBAIHZvaWQgdmhvc3RfZGV2 X2NsZWFudXAoc3RydWN0IHZob3N0X2RldiAqZGV2KQo+ID4gPiA+ICAJaW50IGk7Cj4gPiA+ID4g IAo+ID4gPiA+ICAJZm9yIChpID0gMDsgaSA8IGRldi0+bnZxczsgKytpKSB7Cj4gPiA+ID4gKwkJ LyogTm8gd29ya2VycyBzaG91bGQgcnVuIGhlcmUgYnkgZGVzaWduLiBIb3dldmVyLCByYWNlcyBo YXZlCj4gPiA+ID4gKwkJICogcHJldmlvdXNseSBvY2N1cnJlZCB3aGVyZSBkcml2ZXJzIGhhdmUg YmVlbiB1bmFibGUgdG8gZmx1c2gKPiA+ID4gPiArCQkgKiBhbGwgd29yayBwcm9wZXJseSBwcmlv ciB0byBjbGVhbi11cC4gIFdpdGhvdXQgYSBzdWNjZXNzZnVsCj4gPiA+ID4gKwkJICogZmx1c2gg dGhlIGd1ZXN0IHdpbGwgbWFsZnVuY3Rpb24sIGJ1dCBhdm9pZGluZyBob3N0IG1lbW9yeQo+ID4g PiA+ICsJCSAqIGNvcnJ1cHRpb24gaW4gdGhvc2UgY2FzZXMgZG9lcyBzZWVtIHByZWZlcmFibGUu Cj4gPiA+ID4gKwkJICovCj4gPiA+ID4gKwkJV0FSTl9PTihtdXRleF9pc19sb2NrZWQoJmRldi0+ dnFzW2ldLT5tdXRleCkpOwo+ID4gPiAKPiA+ID4gU28geW91IGFyZSB0cmFkaW5nIG9uZSBzeXpi b3QgdHJpZ2dlcmVkIGlzc3VlIGZvciBhbm90aGVyIG9uZSBpbiB0aGUKPiA+ID4gZnV0dXJlPyAg OikKPiA+ID4gCj4gPiA+IElmIHRoaXMgZXZlciBjYW4gaGFwcGVuLCBoYW5kbGUgaXQsIGJ1dCBk b24ndCBsb2cgaXQgd2l0aCBhIFdBUk5fT04oKSBhcwo+ID4gPiB0aGF0IHdpbGwgdHJpZ2dlciB0 aGUgcGFuaWMtb24td2FybiBib3hlcywgYXMgd2VsbCBhcyBzeXpib3QuICBVbmxlc3MKPiA+ID4g eW91IHdhbnQgdGhhdCB0byBoYXBwZW4/Cj4gPiAKPiA+IE5vLCBTeXpib3QgZG9lc24ndCByZXBv cnQgd2FybmluZ3MsIG9ubHkgQlVHcyBhbmQgbWVtb3J5IGNvcnJ1cHRpb24uCj4gCj4gSGFzIGl0 IGNoYW5nZWQ/ICBMYXN0IEkgbG9va2VkLCBpdCBkaWQgdHJpZ2dlciBvbiBXQVJOXyogY2FsbHMs IHdoaWNoCj4gaGFzIHJlc3VsdGVkIGluIGEgaHVnZSBudW1iZXIgb2Yga2VybmVsIGZpeGVzIGJl Y2F1c2Ugb2YgdGhhdC4KCkV2ZXJ5dGhpbmcgaXMgY3VzdG9taXNhYmxlIGluIHN5emthbGxlciwg c28gbWF5YmUgdGhlcmUgYXJlIHNwZWNpZmljCmJ1aWxkcyB3aGljaCBwYW5pY19vbl93YXJuIGVu YWJsZWQsIGJ1dCBub25lIHRoYXQgSSdtIGludm9sdmVkIHdpdGgKZG8uCgpIZXJlIGZvbGxvd3Mg YSB0b3BpY2FsIGV4YW1wbGUuICBUaGUgcmVwb3J0IGFib3ZlIGluIHRoZSBMaW5rOiB0YWcKY29t ZXMgd2l0aCBhIGNyYXNobG9nIFswXS4gIEluIHRoZXJlIHlvdSBjYW4gc2VlIHRoZSBXQVJOKCkg YXQgdGhlCmJvdHRvbSBvZiB2aG9zdF9kZXZfY2xlYW51cCgpIHRyaWdnZXIgbWFueSB0aW1lcyBk dWUgdG8gYSBwb3B1bGF0ZWQKKG5vbi1mbHVzaGVkKSB3b3JrZXIgbGlzdCwgYmVmb3JlIGZpbmFs bHkgdHJpcHBpbmcgdGhlIEJVRygpIHdoaWNoCnRyaWdnZXJzIHRoZSByZXBvcnQ6CgpbMF0gaHR0 cHM6Ly9zeXprYWxsZXIuYXBwc3BvdC5jb20vdGV4dD90YWc9Q3Jhc2hMb2cmeD0xNmE2MWZjZTcw MDAwMAoKPiA+ID4gQW5kIHdoYXQgaGFwcGVucyBpZiB0aGUgbXV0ZXggaXMgbG9ja2VkIF9SSUdI VF8gYWZ0ZXIgeW91IGNoZWNrZWQgaXQ/Cj4gPiA+IFlvdSBzdGlsbCBoYXZlIGEgcmFjZS4uLgo+ ID4gCj4gPiBObywgd2UgbWlzcyBhIHdhcm5pbmcgdGhhdCBvbmUgdGltZS4gIE1lbW9yeSBpcyBz dGlsbCBwcm90ZWN0ZWQuCj4gCj4gVGhlbiBkb24ndCB3YXJuIG9uIHNvbWV0aGluZyB0aGF0IGRv ZXNuJ3QgbWF0dGVyLiAgVGhpcyBsaW5lIGNhbiBiZQo+IGRyb3BwZWQgYXMgdGhlcmUncyBub3Ro aW5nIGFueW9uZSBjYW4gZG8gYWJvdXQgaXQsIHJpZ2h0PwoKWW91J2xsIGhhdmUgdG8gdGFrZSB0 aGF0IHBvaW50IHVwIHdpdGggTWljaGFlbC4KCi0tIApMZWUgSm9uZXMgW+adjueQvOaWr10KUHJp bmNpcGFsIFRlY2huaWNhbCBMZWFkIC0gRGV2ZWxvcGVyIFNlcnZpY2VzCkxpbmFyby5vcmcg4pSC IE9wZW4gc291cmNlIHNvZnR3YXJlIGZvciBBcm0gU29DcwpGb2xsb3cgTGluYXJvOiBGYWNlYm9v ayB8IFR3aXR0ZXIgfCBCbG9nCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fClZpcnR1YWxpemF0aW9uIG1haWxpbmcgbGlzdApWaXJ0dWFsaXphdGlvbkBsaXN0 cy5saW51eC1mb3VuZGF0aW9uLm9yZwpodHRwczovL2xpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcv bWFpbG1hbi9saXN0aW5mby92aXJ0dWFsaXphdGlvbg==