Re: [PATCH 06/20] x86/msr: Standardize on 'u32' MSR indices in

Xin Li
2025-04-10T06:53:14Z

On Apr 9, 2025, at 11:41 PM, Ingo Molnar <mingo@kernel.org> wrote:
>>
>> not worth it at all?
>
> No:
>
> - Using 'const' for input parameter pointers makes sense because it's
> easy to have a bug like this in a utility function:
>
> obj_ptr->val = foo;
>
> this has a side effect on the calling context, spreading the local
> rot, so to speak, corrupting the object not owned by this function.
>
> - Using 'const' for non-pointer input parameters makes little sense,
> because the worst a function can do is to corrupt it locally:
>
> val_high = foo;
>
> ... but this bug won't be able to spread via corrupting objects
> through a pointer, any bug will be limited to that function.
>
> So neither the kernel, nor any of the major libraries such as glibc
> will typically use const for non-pointer function parameters, outside
> of very specific exceptions that strengthen the rule.

Thanks for the explanation!