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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 3C614C433E6 for ; Fri, 12 Mar 2021 02:40:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E5FE64F90 for ; Fri, 12 Mar 2021 02:40:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229737AbhCLCkJ (ORCPT ); Thu, 11 Mar 2021 21:40:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231434AbhCLCjq (ORCPT ); Thu, 11 Mar 2021 21:39:46 -0500 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BEE2FC061760 for ; Thu, 11 Mar 2021 18:39:46 -0800 (PST) Received: by mail-pg1-x529.google.com with SMTP id o38so14898682pgm.9 for ; Thu, 11 Mar 2021 18:39:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=bWbXoBSRfLL/FoTdQfLfpXolWUy5m83XPY+H7QO24j0=; b=evzkYQgPA8nzFkbfdQKvRQL6ieuUkCwpRnth+avWnhVog6oBX6wwEDiqjRSV5zJc4/ a0uxnzyPyJry3x4YSS1x4Kmnn2YsoxzEP8f6D0kWamIfwpqHbY5Y0/qY/FWzHxMfwihz yUkW/BECzVzHTMH03Su4DS19ldO5mtf+x1ZZM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=bWbXoBSRfLL/FoTdQfLfpXolWUy5m83XPY+H7QO24j0=; b=eCqWBO1HscaPUxX9ku70l5dQ/iZcrM92rdwK7Wf8D21b5X/dhZXJjfmf5yAtxHdZO8 aB0jVaVLxN8khfQ3Vjo8dWveeGfawUXCJVDxy/G8HIv1dX4J5vMFbv7VkFbNcyAHVsrU BxrCFHi1KDNLS0zZNkNsXiuCStesyu/s821dU4W+m4A5YCrPW1Zr/Yf5Mc/Q7EPRtHxn Ca+0KN4+z+APPYp6/SZ+DIIdRoWJTlUPbGQgnujFOjop32/SIGQMQs/4WoVW+VvnuRON PJQ2sTmGRQdpoSNQBK9yFCwMDiyhTC/IRtL9AV+mTVVW5fh5BbWVfJMLVokVwLOcUiho T2xg== X-Gm-Message-State: AOAM532b1CX3wPlcUByFvrus2clAZ/XaP2QmtC3jTRd5JssDGzsKNYVm OfJl6Z4tMlq1Eow1hdttc3egew== X-Google-Smtp-Source: ABdhPJwhrU4emOD5WayCUMZ7IN6WHeCVuTJ7ryuE6Iq+KPE0SNSElLD+CiEu3EiXqH08G+7H37jG2g== X-Received: by 2002:a05:6a00:16c7:b029:1b6:68a6:985a with SMTP id l7-20020a056a0016c7b02901b668a6985amr10384578pfc.44.1615516786330; Thu, 11 Mar 2021 18:39:46 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t22sm393058pjo.45.2021.03.11.18.39.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Mar 2021 18:39:45 -0800 (PST) Date: Thu, 11 Mar 2021 18:39:44 -0800 From: Kees Cook To: Sami Tolvanen Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 01/17] add support for Clang CFI Message-ID: <202103111839.4A4375E@keescook> References: <20210312004919.669614-1-samitolvanen@google.com> <20210312004919.669614-2-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210312004919.669614-2-samitolvanen@google.com> Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, Mar 11, 2021 at 04:49:03PM -0800, Sami Tolvanen wrote: > This change adds support for Clang’s forward-edge Control Flow > Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler > injects a runtime check before each indirect function call to ensure > the target is a valid function with the correct static type. This > restricts possible call targets and makes it more difficult for > an attacker to exploit bugs that allow the modification of stored > function pointers. For more details, see: > > https://clang.llvm.org/docs/ControlFlowIntegrity.html > > Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain > visibility to possible call targets. Kernel modules are supported > with Clang’s cross-DSO CFI mode, which allows checking between > independently compiled components. > > With CFI enabled, the compiler injects a __cfi_check() function into > the kernel and each module for validating local call targets. For > cross-module calls that cannot be validated locally, the compiler > calls the global __cfi_slowpath_diag() function, which determines > the target module and calls the correct __cfi_check() function. This > patch includes a slowpath implementation that uses __module_address() > to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a > shadow map that speeds up module look-ups by ~3x. > > Clang implements indirect call checking using jump tables and > offers two methods of generating them. With canonical jump tables, > the compiler renames each address-taken function to .cfi > and points the original symbol to a jump table entry, which passes > __cfi_check() validation. This isn’t compatible with stand-alone > assembly code, which the compiler doesn’t instrument, and would > result in indirect calls to assembly code to fail. Therefore, we > default to using non-canonical jump tables instead, where the compiler > generates a local jump table entry .cfi_jt for each > address-taken function, and replaces all references to the function > with the address of the jump table entry. > > Note that because non-canonical jump table addresses are local > to each component, they break cross-module function address > equality. Specifically, the address of a global function will be > different in each module, as it's replaced with the address of a local > jump table entry. If this address is passed to a different module, > it won’t match the address of the same function taken there. This > may break code that relies on comparing addresses passed from other > components. > > CFI checking can be disabled in a function with the __nocfi attribute. > Additionally, CFI can be disabled for an entire compilation unit by > filtering out CC_FLAGS_CFI. > > By default, CFI failures result in a kernel panic to stop a potential > exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the > kernel prints out a rate-limited warning instead, and allows execution > to continue. This option is helpful for locating type mismatches, but > should only be enabled during development. > > Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook -- Kees Cook 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=-9.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 EA784C433E0 for ; Fri, 12 Mar 2021 02:41:29 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9346264F87 for ; Fri, 12 Mar 2021 02:41:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9346264F87 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=sAVCOb48L8nHeJv1SoRvQeeOux4HTEbRVp1f4n9MHng=; b=m2wJ/UiYPlmJJityTvmSG7Z/k 7oBuj8/qjphUu6PhHIBbHydyiyuJMQ1IcFn2k80Jb4ftbrrMqbFUF3QY1gWQF9Ii2AZOd4anjPRcw TdMiDiKOdY7CPMIWE2E6ckVKFQX9wuiUDviniPWp+P12Kxc7AMUV7R0m9lu8Cg2310mA4l5fPd8N+ 29nboqafRXoennlDGV7Ae3PiH1XNG/FP5BxufAYhS06NQiSQdkVwGdsY/Spoz177bvg+AGjmxh9Mg fFfneADwJ2rR64xwkupf5gyhlb9B45qyuvFG6LCrhAi33d6/NCh5kls05VY5NVq1ut/urhFuLSBbs 2KVJtGuRw==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lKXiV-00AU4o-Bq; Fri, 12 Mar 2021 02:39:55 +0000 Received: from mail-pf1-x436.google.com ([2607:f8b0:4864:20::436]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lKXiO-00AU4D-05 for linux-arm-kernel@lists.infradead.org; Fri, 12 Mar 2021 02:39:52 +0000 Received: by mail-pf1-x436.google.com with SMTP id y67so871921pfb.2 for ; Thu, 11 Mar 2021 18:39:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=bWbXoBSRfLL/FoTdQfLfpXolWUy5m83XPY+H7QO24j0=; b=evzkYQgPA8nzFkbfdQKvRQL6ieuUkCwpRnth+avWnhVog6oBX6wwEDiqjRSV5zJc4/ a0uxnzyPyJry3x4YSS1x4Kmnn2YsoxzEP8f6D0kWamIfwpqHbY5Y0/qY/FWzHxMfwihz yUkW/BECzVzHTMH03Su4DS19ldO5mtf+x1ZZM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=bWbXoBSRfLL/FoTdQfLfpXolWUy5m83XPY+H7QO24j0=; b=U8HDbt3ErSQPiGJwTUFKigwvnh+6cs3qlcr1bjMHE10whUhwG6KUf2ZpJxeW29M0RZ 7MqXT4zbPSKQkKpc/WF/kBoralfiXLmCoeeSMxdUttIzs8tpvsQWvajNZBf6MXAVHD9Z f1tjV8oAQ4wYrsgEr6VMqni7QwrLngIFkEvSm9f5KURrFskWHZ5QJD8ymCadY2GpM4Z3 7s0Juv3D9vRW1UsEg9MA6jdSoORiMmPwEVz91iXHF9UnSS7/BpLiHG/e28h8cGE75UpX RA497ceVNjwmnnBbddk4tw59hBQrGUkv57huQwgOAB0wvQOz8quSIKAqA238TtQfhaEm Ze1Q== X-Gm-Message-State: AOAM5324s7iqD7/OZZOVoqjhZm0GyH7IbMGrAnCuDC9jgLfYMVTEeuNY SjJd6A/G3d4aeGxtI0bJyaCx9Q== X-Google-Smtp-Source: ABdhPJwhrU4emOD5WayCUMZ7IN6WHeCVuTJ7ryuE6Iq+KPE0SNSElLD+CiEu3EiXqH08G+7H37jG2g== X-Received: by 2002:a05:6a00:16c7:b029:1b6:68a6:985a with SMTP id l7-20020a056a0016c7b02901b668a6985amr10384578pfc.44.1615516786330; Thu, 11 Mar 2021 18:39:46 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id t22sm393058pjo.45.2021.03.11.18.39.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Mar 2021 18:39:45 -0800 (PST) Date: Thu, 11 Mar 2021 18:39:44 -0800 From: Kees Cook To: Sami Tolvanen Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 01/17] add support for Clang CFI Message-ID: <202103111839.4A4375E@keescook> References: <20210312004919.669614-1-samitolvanen@google.com> <20210312004919.669614-2-samitolvanen@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210312004919.669614-2-samitolvanen@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210312_023950_929479_010A2C7D X-CRM114-Status: GOOD ( 25.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gVGh1LCBNYXIgMTEsIDIwMjEgYXQgMDQ6NDk6MDNQTSAtMDgwMCwgU2FtaSBUb2x2YW5lbiB3 cm90ZToKPiBUaGlzIGNoYW5nZSBhZGRzIHN1cHBvcnQgZm9yIENsYW5n4oCZcyBmb3J3YXJkLWVk Z2UgQ29udHJvbCBGbG93Cj4gSW50ZWdyaXR5IChDRkkpIGNoZWNraW5nLiBXaXRoIENPTkZJR19D RklfQ0xBTkcsIHRoZSBjb21waWxlcgo+IGluamVjdHMgYSBydW50aW1lIGNoZWNrIGJlZm9yZSBl YWNoIGluZGlyZWN0IGZ1bmN0aW9uIGNhbGwgdG8gZW5zdXJlCj4gdGhlIHRhcmdldCBpcyBhIHZh bGlkIGZ1bmN0aW9uIHdpdGggdGhlIGNvcnJlY3Qgc3RhdGljIHR5cGUuIFRoaXMKPiByZXN0cmlj dHMgcG9zc2libGUgY2FsbCB0YXJnZXRzIGFuZCBtYWtlcyBpdCBtb3JlIGRpZmZpY3VsdCBmb3IK PiBhbiBhdHRhY2tlciB0byBleHBsb2l0IGJ1Z3MgdGhhdCBhbGxvdyB0aGUgbW9kaWZpY2F0aW9u IG9mIHN0b3JlZAo+IGZ1bmN0aW9uIHBvaW50ZXJzLiBGb3IgbW9yZSBkZXRhaWxzLCBzZWU6Cj4g Cj4gICBodHRwczovL2NsYW5nLmxsdm0ub3JnL2RvY3MvQ29udHJvbEZsb3dJbnRlZ3JpdHkuaHRt bAo+IAo+IENsYW5nIHJlcXVpcmVzIENPTkZJR19MVE9fQ0xBTkcgdG8gYmUgZW5hYmxlZCB3aXRo IENGSSB0byBnYWluCj4gdmlzaWJpbGl0eSB0byBwb3NzaWJsZSBjYWxsIHRhcmdldHMuIEtlcm5l bCBtb2R1bGVzIGFyZSBzdXBwb3J0ZWQKPiB3aXRoIENsYW5n4oCZcyBjcm9zcy1EU08gQ0ZJIG1v ZGUsIHdoaWNoIGFsbG93cyBjaGVja2luZyBiZXR3ZWVuCj4gaW5kZXBlbmRlbnRseSBjb21waWxl ZCBjb21wb25lbnRzLgo+IAo+IFdpdGggQ0ZJIGVuYWJsZWQsIHRoZSBjb21waWxlciBpbmplY3Rz IGEgX19jZmlfY2hlY2soKSBmdW5jdGlvbiBpbnRvCj4gdGhlIGtlcm5lbCBhbmQgZWFjaCBtb2R1 bGUgZm9yIHZhbGlkYXRpbmcgbG9jYWwgY2FsbCB0YXJnZXRzLiBGb3IKPiBjcm9zcy1tb2R1bGUg Y2FsbHMgdGhhdCBjYW5ub3QgYmUgdmFsaWRhdGVkIGxvY2FsbHksIHRoZSBjb21waWxlcgo+IGNh bGxzIHRoZSBnbG9iYWwgX19jZmlfc2xvd3BhdGhfZGlhZygpIGZ1bmN0aW9uLCB3aGljaCBkZXRl cm1pbmVzCj4gdGhlIHRhcmdldCBtb2R1bGUgYW5kIGNhbGxzIHRoZSBjb3JyZWN0IF9fY2ZpX2No ZWNrKCkgZnVuY3Rpb24uIFRoaXMKPiBwYXRjaCBpbmNsdWRlcyBhIHNsb3dwYXRoIGltcGxlbWVu dGF0aW9uIHRoYXQgdXNlcyBfX21vZHVsZV9hZGRyZXNzKCkKPiB0byByZXNvbHZlIGNhbGwgdGFy Z2V0cywgYW5kIHdpdGggQ09ORklHX0NGSV9DTEFOR19TSEFET1cgZW5hYmxlZCwgYQo+IHNoYWRv dyBtYXAgdGhhdCBzcGVlZHMgdXAgbW9kdWxlIGxvb2stdXBzIGJ5IH4zeC4KPiAKPiBDbGFuZyBp bXBsZW1lbnRzIGluZGlyZWN0IGNhbGwgY2hlY2tpbmcgdXNpbmcganVtcCB0YWJsZXMgYW5kCj4g b2ZmZXJzIHR3byBtZXRob2RzIG9mIGdlbmVyYXRpbmcgdGhlbS4gV2l0aCBjYW5vbmljYWwganVt cCB0YWJsZXMsCj4gdGhlIGNvbXBpbGVyIHJlbmFtZXMgZWFjaCBhZGRyZXNzLXRha2VuIGZ1bmN0 aW9uIHRvIDxmdW5jdGlvbj4uY2ZpCj4gYW5kIHBvaW50cyB0aGUgb3JpZ2luYWwgc3ltYm9sIHRv IGEganVtcCB0YWJsZSBlbnRyeSwgd2hpY2ggcGFzc2VzCj4gX19jZmlfY2hlY2soKSB2YWxpZGF0 aW9uLiBUaGlzIGlzbuKAmXQgY29tcGF0aWJsZSB3aXRoIHN0YW5kLWFsb25lCj4gYXNzZW1ibHkg Y29kZSwgd2hpY2ggdGhlIGNvbXBpbGVyIGRvZXNu4oCZdCBpbnN0cnVtZW50LCBhbmQgd291bGQK PiByZXN1bHQgaW4gaW5kaXJlY3QgY2FsbHMgdG8gYXNzZW1ibHkgY29kZSB0byBmYWlsLiBUaGVy ZWZvcmUsIHdlCj4gZGVmYXVsdCB0byB1c2luZyBub24tY2Fub25pY2FsIGp1bXAgdGFibGVzIGlu c3RlYWQsIHdoZXJlIHRoZSBjb21waWxlcgo+IGdlbmVyYXRlcyBhIGxvY2FsIGp1bXAgdGFibGUg ZW50cnkgPGZ1bmN0aW9uPi5jZmlfanQgZm9yIGVhY2gKPiBhZGRyZXNzLXRha2VuIGZ1bmN0aW9u LCBhbmQgcmVwbGFjZXMgYWxsIHJlZmVyZW5jZXMgdG8gdGhlIGZ1bmN0aW9uCj4gd2l0aCB0aGUg YWRkcmVzcyBvZiB0aGUganVtcCB0YWJsZSBlbnRyeS4KPiAKPiBOb3RlIHRoYXQgYmVjYXVzZSBu b24tY2Fub25pY2FsIGp1bXAgdGFibGUgYWRkcmVzc2VzIGFyZSBsb2NhbAo+IHRvIGVhY2ggY29t cG9uZW50LCB0aGV5IGJyZWFrIGNyb3NzLW1vZHVsZSBmdW5jdGlvbiBhZGRyZXNzCj4gZXF1YWxp dHkuIFNwZWNpZmljYWxseSwgdGhlIGFkZHJlc3Mgb2YgYSBnbG9iYWwgZnVuY3Rpb24gd2lsbCBi ZQo+IGRpZmZlcmVudCBpbiBlYWNoIG1vZHVsZSwgYXMgaXQncyByZXBsYWNlZCB3aXRoIHRoZSBh ZGRyZXNzIG9mIGEgbG9jYWwKPiBqdW1wIHRhYmxlIGVudHJ5LiBJZiB0aGlzIGFkZHJlc3MgaXMg cGFzc2VkIHRvIGEgZGlmZmVyZW50IG1vZHVsZSwKPiBpdCB3b27igJl0IG1hdGNoIHRoZSBhZGRy ZXNzIG9mIHRoZSBzYW1lIGZ1bmN0aW9uIHRha2VuIHRoZXJlLiBUaGlzCj4gbWF5IGJyZWFrIGNv ZGUgdGhhdCByZWxpZXMgb24gY29tcGFyaW5nIGFkZHJlc3NlcyBwYXNzZWQgZnJvbSBvdGhlcgo+ IGNvbXBvbmVudHMuCj4gCj4gQ0ZJIGNoZWNraW5nIGNhbiBiZSBkaXNhYmxlZCBpbiBhIGZ1bmN0 aW9uIHdpdGggdGhlIF9fbm9jZmkgYXR0cmlidXRlLgo+IEFkZGl0aW9uYWxseSwgQ0ZJIGNhbiBi ZSBkaXNhYmxlZCBmb3IgYW4gZW50aXJlIGNvbXBpbGF0aW9uIHVuaXQgYnkKPiBmaWx0ZXJpbmcg b3V0IENDX0ZMQUdTX0NGSS4KPiAKPiBCeSBkZWZhdWx0LCBDRkkgZmFpbHVyZXMgcmVzdWx0IGlu IGEga2VybmVsIHBhbmljIHRvIHN0b3AgYSBwb3RlbnRpYWwKPiBleHBsb2l0LiBDT05GSUdfQ0ZJ X1BFUk1JU1NJVkUgZW5hYmxlcyBhIHBlcm1pc3NpdmUgbW9kZSwgd2hlcmUgdGhlCj4ga2VybmVs IHByaW50cyBvdXQgYSByYXRlLWxpbWl0ZWQgd2FybmluZyBpbnN0ZWFkLCBhbmQgYWxsb3dzIGV4 ZWN1dGlvbgo+IHRvIGNvbnRpbnVlLiBUaGlzIG9wdGlvbiBpcyBoZWxwZnVsIGZvciBsb2NhdGlu ZyB0eXBlIG1pc21hdGNoZXMsIGJ1dAo+IHNob3VsZCBvbmx5IGJlIGVuYWJsZWQgZHVyaW5nIGRl dmVsb3BtZW50Lgo+IAo+IFNpZ25lZC1vZmYtYnk6IFNhbWkgVG9sdmFuZW4gPHNhbWl0b2x2YW5l bkBnb29nbGUuY29tPgoKUmV2aWV3ZWQtYnk6IEtlZXMgQ29vayA8a2Vlc2Nvb2tAY2hyb21pdW0u b3JnPgoKLS0gCktlZXMgQ29vawoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX18KbGludXgtYXJtLWtlcm5lbCBtYWlsaW5nIGxpc3QKbGludXgtYXJtLWtlcm5l bEBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQub3JnL21haWxtYW4v bGlzdGluZm8vbGludXgtYXJtLWtlcm5lbAo=