[PATCH trivial] arm64: constify hwcap_str

[Ard Biesheuvel]

On 7 November 2013 18:50, Catalin Marinas <catalin.marinas at arm.com> wrote:
> On Wed, Nov 06, 2013 at 04:32:47PM +0000, Ard Biesheuvel wrote:
>> Turn hwcap_str from a 'writable array of pointers to const char[]'
>> to a multidimensional const char[][].
>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
>> ---
>>
>> This is something I noticed when looking at Steve Capper's hwcaps patch: really
>> no point in having a writable array of 8-byte pointers in .data keeping track of
>> these hwcap strings.
>
> I don't see a problem (few bytes wasted). If you want to make it
> read-only, this would do:
>
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index 9cf30f49610d..84a770fd7003 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -308,7 +308,7 @@ static int __init topology_init(void)
>  }
>  subsys_initcall(topology_init);
>
> -static const char *hwcap_str[] = {
> +static const char *const hwcap_str[] = {
>         "fp",
>         "asimd",
>         NULL
>

I agree that whether you want to put up with the additional layer of
indirection, additional relocations etc is a matter of taste, but
having writable pointers around that are easily dereferenced directly
by unprivileged users is a bad idea in any case, so if this is your
preferred solution, it's fine by me.

Regards,
Ard.