Re: [PATCH] bcache: make kobj_type structures constant

From: Coly Li
Date: Wed Apr 05 2023 - 09:38:22 EST




> 2023年4月5日 01:38,Thomas Weißschuh <linux@xxxxxxxxxxxxxx> 写道:
>
> Hi Coly,
>
> On 2023-02-15 00:16:03+0800, Coly Li wrote:
>>> 2023年2月14日 23:21,Thomas Weißschuh <linux@xxxxxxxxxxxxxx> 写道:
>>>
>>> On Tue, Feb 14, 2023 at 05:51:09PM +0800, Coly Li wrote:
>>>>
>>>>
>>>>> 2023年2月14日 11:13,Thomas Weißschuh <linux@xxxxxxxxxxxxxx> 写道:
>>>>>
>>>>> Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.")
>>>>> the driver core allows the usage of const struct kobj_type.
>>>>>
>>>>> Take advantage of this to constify the structure definitions to prevent
>>>>> modification at runtime.
>>>>>
>>>>
>>>> How the const structure definition can prevent modification at run time?
>>>
>>> It will be put into .rodata instead of .data by the compiler.
>>> The .rodata section is mapped as read-only via the pagetable.
>>>
>>> See Documentation/security/self-protection.rst
>>> "Function pointers and sensitive variables must not be writable".
>>
>> I see. Thanks for the information.
>>
>> This patch will be added into my testing queue, and submitted later.
>
> It seems this was not submitted.
> Or did I miss it?

No I don’t submit it yet. It is not emergent fix, and stay with other testing patches together.

Do you want it to go now?

Coly Li