Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Mime-Version: 1.0
Subject: RE: [RFC] vsprintf: compile error on %09pK
Reply-To: jaewon31.kim@samsung.com
Sender: Jaewon Kim <jaewon31.kim@samsung.com>
From:   Jaewon Kim <jaewon31.kim@samsung.com>
To:     David Laight <David.Laight@ACULAB.COM>,
        'Jaewon Kim' <jaewon31.kim@gmail.com>,
        Petr Mladek <pmladek@suse.com>
CC:     Jaewon Kim <jaewon31.kim@samsung.com>,
        "senozhatsky@chromium.org" <senozhatsky@chromium.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        GyeongHwan Hong <gh21.hong@samsung.com>
In-Reply-To: <694722c9409b43808cfbc1fc9e495016@AcuMS.aculab.com>
Message-ID: <20230404101201epcms1p615a6365e64fc6e0a0fa203d41404940c@epcms1p6>
Date:   Tue, 04 Apr 2023 19:12:01 +0900
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset="utf-8"
CMS-TYPE: 101P
DLP-Filter: Pass
References: <694722c9409b43808cfbc1fc9e495016@AcuMS.aculab.com>
        <20230403104617epcms1p383bacbca705c0d7e4fffca6833050e42@epcms1p3>
        <ZCrMMQt2xnnZIyz6@alley>
        <CAJrd-Uvzy18SfjjqbqZCPHjw+ujQXsBpvov4b=bfAwZrj=bCAA@mail.gmail.com>
        <CGME20230403104617epcms1p383bacbca705c0d7e4fffca6833050e42@epcms1p6>
Precedence: bulk

>From: Jaewon Kim
>> Sent: 03 April 2023 15:40
>...
>> I wanted to print phys_addr_t  type value only when kptr_restrict sysctl is
>> allowed. So I thought I could use %pK for that purpose. And the physical
>> address is not that long. I wanted to make that length short like 9 hex.
>
>Isn't that is the wrong format for physical addresses anyway?
>They can be larger than virtual ones (eg x86 with PAE).

Yeah, correct. I just used %pK to hide physical address, I thought it could be
leak in security perspective. Could you give me advice how I can hide the
address by default and look the address if kptr_restrict allow it?

Jaewon Kim

>
>	David