linux-kernel - Re: [PATCH 1/7] mips: dmi: Fix early remap on MIPS32

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

Message-Id: <245d3985-9085-4be0-8c74-d95d06334584@app.fastmail.com>
Date:   Thu, 23 Nov 2023 17:33:31 +0000
From:   "Jiaxun Yang" <jiaxun.yang@...goat.com>
To:     "Thomas Bogendoerfer" <tsbogend@...ha.franken.de>
Cc:     "Serge Semin" <fancer.lancer@...il.com>,
        "Arnd Bergmann" <arnd@...db.de>,
        "Andrew Morton" <akpm@...ux-foundation.org>,
        "Mike Rapoport" <rppt@...nel.org>,
        "Matthew Wilcox" <willy@...radead.org>,
        "Tiezhu Yang" <yangtiezhu@...ngson.cn>,
        "Huacai Chen" <chenhuacai@...nel.org>,
        "Yinglu Yang" <yangyinglu@...ngson.cn>,
        "Alexey Malahov" <Alexey.Malahov@...kalelectronics.ru>,
        "Aleksandar Rikalo" <aleksandar.rikalo@...mia.com>,
        "Aleksandar Rikalo" <arikalo@...il.com>,
        "Dragan Mladjenovic" <dragan.mladjenovic@...mia.com>,
        "Chao-ying Fu" <cfu@...ecomp.com>, "Marc Zyngier" <maz@...nel.org>,
        "linux-mips@...r.kernel.org" <linux-mips@...r.kernel.org>,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/7] mips: dmi: Fix early remap on MIPS32



在2023年11月23日十一月 下午4:07，Thomas Bogendoerfer写道：
> On Thu, Nov 23, 2023 at 03:07:09PM +0000, Jiaxun Yang wrote:
>> 
[...]
>
> the problem with all 32bit unmapped segments is their limitations in
> size. But there is always room to try to use unmapped and fall back
> to mapped, if it doesn't work. But I doubt anybody is going to
> implement that.

Yep, I guess fallback should be implemented for ioremap_cache as well.

>
>> >> AFAIK for Loongson DMI is located at cached memory so using ioremap_uc
>> >> blindly will cause inconsistency.
>> >
>> > why ?
>> 
>> Firmware sometimes does not flush those tables from cache back to memory.
>> For Loongson systems (as well as most MTI systems) cache is enabled by
>> firmware.
>
> kernel flushes all caches on startup, so there shouldn't be a problem.

Actually dmi_setup() is called before cpu_cache_init().

Thanks
>
> Thomas.
>
> -- 
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]

-- 
- Jiaxun