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 86962C433EF for ; Wed, 11 May 2022 18:05:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346048AbiEKSFB (ORCPT ); Wed, 11 May 2022 14:05:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233707AbiEKSE6 (ORCPT ); Wed, 11 May 2022 14:04:58 -0400 Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91543B36F3 for ; Wed, 11 May 2022 11:04:56 -0700 (PDT) Received: by mail-pf1-x42a.google.com with SMTP id bo5so2655968pfb.4 for ; Wed, 11 May 2022 11:04:56 -0700 (PDT) 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:in-reply-to; bh=5mKxMRQlQWPwu4mRllmx6ShZNHltflA3/hsURvdMH9A=; b=JzVH0E99WgNhNFtMfddusYX9t0PPvm7mYKeZDoS8KfHQDtCr1maZaOZ5krlAKZPJj/ kSW4plzUCRDHuBBSuGeuHXr5pNILn1GReHmBdfnA/5z52hs8xsQzrNoaHGtSV7hNJTQA 0ENT+HjHkqcKTTG9DCNwsmW7oYcqPsEGF7CgU= 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:in-reply-to; bh=5mKxMRQlQWPwu4mRllmx6ShZNHltflA3/hsURvdMH9A=; b=VRynZTwrFaIGhkHHzhN3A65F9C8OSwnRcg8Pv7/GChxlH9000mRamIFhPyjq5Mqal5 FleAan45ODH9O8j34k2ABRdtlGZjaGbfN0YwOQ5vaXIfQe6s5CLQXMZmuC6tGwL8cVxn 5iaqm6ohVXwkLbzFP+f4jeWEay8dTgkEDLkCkG0/2PC+UY10rVRPbO1XSyOq+Eyxp+tP Hm1n5o2c9w1luVHKdXeqBQ/V8IL0mcTM0DQE5gGm4/V6mOdN5TVMX8PX/H61yU7AebTg RIBTqa+JJIWk7LTLk1CxmUCvfN7Fa3puEQoZZlLo/pvx9OwM3puzdFT4ZiUEdQmH6j5Y NPBw== X-Gm-Message-State: AOAM530ZpODjXlVxAABmRhj5BHEd9a7mI5UXglZcfKOZAe7ykWnQpu9w x3RWEezdvZzbmrNaFbEwoAy5O+f2iBvRiw== X-Google-Smtp-Source: ABdhPJyPos/XQ6ildWdXQ1gBpyfJs9fGclLfzv5zJqzYDzl9/thflZeTxuO7AI0vh5ZVkV1EYH8wuQ== X-Received: by 2002:a05:6a00:140c:b0:4e1:530c:edc0 with SMTP id l12-20020a056a00140c00b004e1530cedc0mr26275217pfu.18.1652292296092; Wed, 11 May 2022 11:04:56 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id l12-20020a170902d34c00b0015e8d4eb296sm2149525plk.224.2022.05.11.11.04.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 May 2022 11:04:55 -0700 (PDT) Date: Wed, 11 May 2022 11:04:55 -0700 From: Kees Cook To: Andy Lutomirski Cc: x86@kernel.org, LKML , Florian Weimer Subject: Re: [PATCH] x86/vsyscall: Remove CONFIG_LEGACY_VSYSCALL_EMULATE Message-ID: <202205111104.464A6619@keescook> References: <898932fe61db6a9d61bc2458fa2f6049f1ca9f5c.1652290558.git.luto@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <898932fe61db6a9d61bc2458fa2f6049f1ca9f5c.1652290558.git.luto@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 11, 2022 at 10:38:53AM -0700, Andy Lutomirski wrote: > CONFIG_LEGACY_VSYSCALL_EMULATE is, as far as I know, only needed for the > combined use of exotic and outdated debugging mechanisms with outdated > binaries. At this point, no one should be using it. We would like to > implement dynamic switching of vsyscalls, but this is much more > complicated to support in EMULATE mode than XONLY mode. > > So let's force all the distros off of EMULATE mode. If anyone actually > needs it, they can set vsyscall=emulate, and we can then get away with > refusing to support newer security models if that option is set. > > Cc: x86@kernel.org > Cc: Kees Cook > Cc: Florian Weimer > Signed-off-by: Andy Lutomirski Sounds legit! Can we switch the default to "none" while we're at it? Reviewed-by: Kees Cook -- Kees Cook