linux-kernel - Re: [PATCH v3 2/3] soc: qcom: ubwc: Get HBB from SMEM

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 for Android: free password hash cracker in your pocket

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

Message-ID: <hunbpvbfkcxzbnwr676z6fncgdhfumjedx7jp5izojusg3rj7f@5te77lmqcdaa>
Date: Fri, 9 Jan 2026 05:21:10 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Bjorn Andersson <andersson@...nel.org>
Cc: Konrad Dybcio <konradybcio@...nel.org>, Kees Cook <kees@...nel.org>,
        "Gustavo A. R. Silva" <gustavoars@...nel.org>,
        Rob Clark <robin.clark@....qualcomm.com>, Sean Paul <sean@...rly.run>,
        Akhil P Oommen <akhilpo@....qualcomm.com>,
        Dmitry Baryshkov <lumag@...nel.org>,
        Abhinav Kumar <abhinav.kumar@...ux.dev>,
        Jessica Zhang <jesszhan0024@...il.com>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-hardening@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        freedreno@...ts.freedesktop.org,
        Konrad Dybcio <konrad.dybcio@....qualcomm.com>
Subject: Re: [PATCH v3 2/3] soc: qcom: ubwc: Get HBB from SMEM

On Thu, Jan 08, 2026 at 11:49:54AM -0600, Bjorn Andersson wrote:
> On Thu, Jan 08, 2026 at 04:45:49PM +0200, Dmitry Baryshkov wrote:
> > On Thu, Jan 08, 2026 at 03:21:51PM +0100, Konrad Dybcio wrote:
> > > From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
> > > 
> > > To make sure the correct settings for a given DRAM configuration get
> > > applied, attempt to retrieve that data from SMEM (which happens to be
> > > what the BSP kernel does, albeit with through convoluted means of the
> > > bootloader altering the DT with this data).
> > > 
> > > Signed-off-by: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
> > > 
> > > ---
> > > I'm not sure about this approach - perhaps a global variable storing
> > > the selected config, which would then be non-const would be better?
> > 
> > I'd prefer if const data was const, split HBB to a separate API.
> > 
> 
> I agree, but I'd prefer to avoid a separate API for it.
> 
> Instead I'd like to either return the struct by value (after updating
> the hbb), but we then loose the ability to return errors, or by changing
> the signature to:
> 
> int qcom_ubwc_config_get_data(struct qcom_ubwc_cfg_data *data)
> 
> This costs us an additional 16 bytes in each client (as the pointer is
> replaced with the data), but I think it's a cleaner API.

What about:

const struct qcom_ubwc_cfg_data qcom_ubwc_config_get_data(u32 *hbb)

I really want to keep the data as const and, as important, use it as a
const pointer.

> 
> Regards,
> Bjorn

-- 
With best wishes
Dmitry