From: "Marvin Häuser" <mhaeuser@posteo.de>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: edk2-devel-groups-io <devel@edk2.groups.io>,
Michael Kinney <michael.d.kinney@intel.com>,
Liming Gao <gaoliming@byosoft.com.cn>,
Jiewen Yao <jiewen.yao@intel.com>,
Michael Kubacki <michael.kubacki@microsoft.com>,
Sean Brogan <sean.brogan@microsoft.com>,
Rebecca Cran <quic_rcran@quicinc.com>,
Leif Lindholm <quic_llindhol@quicinc.com>,
Sami Mujawar <sami.mujawar@arm.com>,
Taylor Beebe <t@taylorbeebe.com>
Subject: Re: [PATCH 3/3] MdeModulePkg/DxeCore: Unconditionally set memory protections
Date: Wed, 8 Feb 2023 18:55:23 +0000 [thread overview]
Message-ID: <76A536C6-42EE-48DB-BF53-810A34E43AE1@posteo.de> (raw)
In-Reply-To: <CAMj1kXH90xYGh2v-Qt8FG=R7tH+waCEgSERw9AjadwMRQZ2kmA@mail.gmail.com>
> On 8. Feb 2023, at 19:49, Ard Biesheuvel <ardb@kernel.org> wrote:
>
> This is all copy-pasted from MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
:(
>
> The ordering here is a bit tricky. As soon as the CPU arch protocol is
> exposed, every allocation will be remapped individually, resulting in
> page table splits and therefore recursion.
So the issue is the order of event handlers or allocations within the event dispatcher? :( Oh lord...
Can we maybe clarify the comment with something like "While DxeCore/InitializeDxeNxMemoryProtectionPolicy() would in theory perform this task, allocations between the protocol installation and the invocation of its event handler may trigger the issue."?
next prev parent reply other threads:[~2023-02-08 18:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-08 17:58 [PATCH 0/3] Apply NX protections more strictly Ard Biesheuvel
2023-02-08 17:58 ` [PATCH 1/3] ArmPkg/ArmMmuLib: Avoid splitting block entries if possible Ard Biesheuvel
2023-02-08 17:58 ` [PATCH 2/3] ArmPkg/CpuDxe: Perform preliminary NX remap of free memory Ard Biesheuvel
2023-02-08 18:32 ` Marvin Häuser
2023-02-08 18:49 ` [edk2-devel] " Ard Biesheuvel
2023-02-08 18:57 ` Taylor Beebe
2023-02-08 22:52 ` Ard Biesheuvel
2023-02-08 17:58 ` [PATCH 3/3] MdeModulePkg/DxeCore: Unconditionally set memory protections Ard Biesheuvel
2023-02-08 18:25 ` Ard Biesheuvel
2023-02-08 18:55 ` Marvin Häuser [this message]
2023-02-08 19:12 ` Taylor Beebe
2023-02-08 22:08 ` Ard Biesheuvel
2023-02-08 22:24 ` Taylor Beebe
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