From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mail-pl1-f178.google.com (mail-pl1-f178.google.com [209.85.214.178])
 by mx.groups.io with SMTP id smtpd.web11.72857.1675732722988071495
 for <devel@edk2.groups.io>;
 Mon, 06 Feb 2023 17:18:43 -0800
Authentication-Results: mx.groups.io;
 dkim=pass header.i=@taylorbeebe.com header.s=google header.b=ZMJJLaBn;
 spf=pass (domain: taylorbeebe.com, ip: 209.85.214.178, mailfrom: t@taylorbeebe.com)
Received: by mail-pl1-f178.google.com with SMTP id r8so14110439pls.2
        for <devel@edk2.groups.io>; Mon, 06 Feb 2023 17:18:42 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=taylorbeebe.com; s=google;
        h=content-transfer-encoding:in-reply-to:from:content-language
         :references:to:subject:user-agent:mime-version:date:message-id:from
         :to:cc:subject:date:message-id:reply-to;
        bh=z8SXRT7ad6dqgSePJq4s0ATFAc3jWCYCiFjGOj4WBg8=;
        b=ZMJJLaBnoaQnbMaWjtzPshw41rAAyzv2DGWKz02BSvQtoFSVwcaxA9Goy0vcrT9lKu
         +VY1mVMD3qUuTHbkKu3S/xZuf6pQZlagTUVy3oiF9taJv6Sm+X384WTt00ebl5hA5pix
         NmK/NmO7YUfSU3bw3ot0mo8LHQcWl9yWQ2/RDO01NkiFTg6010/mEwes2NNjRH4lHwGK
         xeQBGGObn7Bfl4vFmNlEqZEYWQT8C+xpjA6ZTyRYgR8yHiW/qNTxddV5tDu9cnN3joXK
         1znpDK+1D8c3p9VPQG8mzJa+sMroh+llFb2sr6pC3Ddo1VHIg/jkQ5tHeAU4I+nbpfCg
         S4Dg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20210112;
        h=content-transfer-encoding:in-reply-to:from:content-language
         :references:to:subject:user-agent:mime-version:date:message-id
         :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to;
        bh=z8SXRT7ad6dqgSePJq4s0ATFAc3jWCYCiFjGOj4WBg8=;
        b=vKt7UaIj/ElzmHEgKPb4Fj4S1YwGv3+heG7RSHscgl2dbgu+Cjq+hKb+Q+GSuSWxHD
         ROdepRJwspk5nL90O3QB0KI0cm827MHO8A/dLM9X6Wipe+eksKyA8NL+bX+4Sj7YrQGb
         PH5WRpmy/qBvOjlJFoCCHtyLOft6Gxb1tl6BRfy41T2ctxBhfVrqfWaAVhKEI2zlsHHy
         u6x+T9XGDR5kBucYdVm2MIcIizj4Yk/Qv4QxguhOc7NfZy7QOwy2QvcgYAwa5/KBVHBu
         JRczYSyXCIFOYYtG6j5pn8o2dzJQtYvUsUxu0bha0OdN+qlCYWGJhvWvjyzuvjI4U48/
         eOsw==
X-Gm-Message-State: AO0yUKXG9+ZMRqUmnwOhbQb2UJbePBQOBCKMs19JoNSjfBU17Bnr8gbw
	ZthB/TIrYIY2N6NQmDLpYvhofA==
X-Google-Smtp-Source: AK7set/9LklNQxt7Jh0FFCZYAmXQVRsHNIA749yaSnHO/Jx6k/SmWT0SEP5k+WtkKmd8vqMRRxE9RQ==
X-Received: by 2002:a05:6a20:ba9e:b0:be:e6d3:797b with SMTP id fb30-20020a056a20ba9e00b000bee6d3797bmr1065150pzb.55.1675732722233;
        Mon, 06 Feb 2023 17:18:42 -0800 (PST)
Return-Path: <t@taylorbeebe.com>
Received: from [192.168.50.162] ([50.46.230.135])
        by smtp.gmail.com with ESMTPSA id w8-20020a1709029a8800b001991a695bd2sm2377696plp.232.2023.02.06.17.18.41
        (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128);
        Mon, 06 Feb 2023 17:18:41 -0800 (PST)
Message-ID: <15a314d3-2549-5ed3-b920-2a71b1ba518a@taylorbeebe.com>
Date: Mon, 6 Feb 2023 17:18:40 -0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.6.1
Subject: Re: [edk2-devel] [PATCH 4/4] ArmPkg/CpuDxe: Implement EFI memory attributes protocol
To: =?UTF-8?Q?Marvin_H=c3=a4user?= <mhaeuser@posteo.de>, devel@edk2.groups.io
References: <db7c3126-2741-d1dc-0ed9-6690a432724f@taylorbeebe.com>
 <17027.1675454285173437530@groups.io>
From: "Taylor Beebe" <t@taylorbeebe.com>
In-Reply-To: <17027.1675454285173437530@groups.io>
Content-Language: en-US
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

I can't see the Bugzilla you referenced so I requested security Bugzilla 
access. But, yes, that's the bug to which I was referring :)

Once Ard's change to add Memory Attribute Protocol support to ARM 
platforms is in, the change you linked may be palatable for the 
upstream. However, ARM platforms could run into the infinite loop I 
outlined if that change is pushed upstream because of the lack of 
per-allocated page tables and a software semaphore to prevent looping.

I implemented pre-allocated pages for ARM a while back in a private repo 
but never committed it to Mu. Maybe that would also be worth committing 
and pushing upstream.

-Taylor

On 2/3/2023 11:58 AM, Marvin Häuser wrote:
> Hi Taylor,
> 
> Do you by any chance mean this bug? 
> https://github.com/microsoft/mu_basecore/blob/release/202208/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c#L1544 <https://github.com/microsoft/mu_basecore/blob/release/202208/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c#L1544>
> 
> I reported this a while ago at 
> https://bugzilla.tianocore.org/show_bug.cgi?id=3316 
> <https://bugzilla.tianocore.org/show_bug.cgi?id=3316>
> 
> The Mu fix is by no means a workaround and actually fixes this issue in 
> a sane way. It should have been fixed upstream ages ago.
> 
> Best regards,
> Marvin
>