linux-kernel - Re: [PATCH] ARM: LPAE: initialize cachepolicy correctly

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]

Date:   Sun, 04 Sep 2016 16:31:40 -0700
From:   Stefan Agner <stefan@...er.ch>
To:     Russell King - ARM Linux <linux@...linux.org.uk>
Cc:     ard.biesheuvel@...aro.org, matt@...eblueprint.co.uk,
        kirill.shutemov@...ux.intel.com, l.stach@...gutronix.de,
        arnd@...db.de, nicolas.pitre@...aro.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ARM: LPAE: initialize cachepolicy correctly

On 2016-09-04 15:09, Russell King - ARM Linux wrote:
> On Sat, Sep 03, 2016 at 10:33:31PM -0700, Stefan Agner wrote:
>> The cachepolicy variable gets initialized using a masked pmd
>> So far, the pmd has been masked with flags valid for the 2-page
>> table format. In the LPAE case, this lead to a wrong assumption
>> of what the initial cachepolicy has been used. Later a check
>> forces the cache policy to writealloc and prints the following
>> warning:
>> Forcing write-allocate cache policy for SMP
>>
>> This patch uses PMD_SECT_WBWA to mask all cache setting flags.
>> The define represents the complete mask of the cache relevant
>> flags for both page table formats.
> 
> PMD_SECT_WBWA is just one possible combination, it's not a bit-mask.
> We need a new definition.

Agreed, it just happens to be the same as the bit-mask in both
page-table layouts.

Does PMD_SECT_CACHE_MASK sounds like a reasonable identifier for it?

--
Stefan