linux-kernel - Re: [PATCH] arm64: dts: qcom: sa8775p: fix the secure device bootup issue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <7b33235f-dbf7-45f9-9e8a-5d69ec8ca863@oss.qualcomm.com>
Date: Mon, 23 Dec 2024 12:56:30 +0100
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Jie Gan <quic_jiegan@...cinc.com>,
        Konrad Dybcio <konrad.dybcio@....qualcomm.com>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konradybcio@...nel.org>, Rob Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>,
        Conor Dooley <conor+dt@...nel.org>
Cc: linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Tingwei Zhang <quic_tingweiz@...cinc.com>,
        Jinlong Mao <quic_jinlmao@...cinc.com>
Subject: Re: [PATCH] arm64: dts: qcom: sa8775p: fix the secure device bootup
 issue

On 20.12.2024 6:51 AM, Jie Gan wrote:
> 
> 
> On 12/20/2024 5:25 AM, Konrad Dybcio wrote:
>> On 19.12.2024 3:52 AM, Jie Gan wrote:
>>> The secure device(fused) cannot bootup with TPDM_DCC device. So
>>> disable it in DT.
>>>
>>> Fixes: 6596118ccdcd ("arm64: dts: qcom: Add coresight nodes for SA8775p")
>>> Signed-off-by: Jie Gan <quic_jiegan@...cinc.com>
>>> ---
>>
>> I was thinking, is there a QFPROM fuse we could read on both
>> secure and non-secure devices to determine whether all coresight
>> components will be accessible, and enable them based on that
>> information?
>>
> There are two known TPDM devices had been disabled on secure device. One of these devices is TPDM_DCC. In downstream code, we have an API to check the secure status of the device in TPDM's probe function, to avoid unintentional enable. The downstream API will check the register that controls crash dump functionality in TZ and the crash dump functionality is disabled by default on secure devices.

That's an "eeeh" type solution, crashdump is a separate thing that may be
enabled independently, and some prod devices from certain vendors actually
do that

> We need to verify if the downstream API is supported by the upstream kernel. We plan to upstream a patch to implement this functionality in the TPDM driver or any other device's driver that needed the functionality.

Please check if there's a coresight-specific fuse instead


> For the time being, we need to disable this TPDM device in DT because the TPDM_DCC will break the bootup process on secure devices.

Yeah, right

Reviewed-by: Konrad Dybcio <konrad.dybcio@....qualcomm.com>

Konrad