Re: [PATCH] ARM: VDSO: put read only/mostly objects into proper sections
From: Nathan Lynch
Date: Wed Aug 10 2016 - 15:05:27 EST
On 08/10/2016 01:47 PM, Kees Cook wrote:
> On Wed, Aug 10, 2016 at 2:59 AM, Jisheng Zhang <jszhang@xxxxxxxxxxx> wrote:
>> + Kees
>>
>> On Wed, 10 Aug 2016 17:09:47 +0800 wrote:
>>
>>> vdso_data_mapping is never modified, so mark it as const.
>>>
>>> vdso_data_page and vdso_text_mapping are initialized by vdso_init(),
>>> thereafter are mostly read during vdso special mapping handling.
>>>
>>> The fact that they are mostly read and not written to makes them
>>> candidates for __read_mostly declarations.
>>
>> Inspired by Kees's "arm: apply more __ro_after_init", is it better
>> to mark these vars as __ro_after_init?
>
> Yeah, if they're not written outside of __init, please do. It would be
> a nice complement to commit 11bf9b865898 ("ARM/vdso: Mark the vDSO
> code read-only after init").
I agree.