Re: [PATCH v2 2/8] arm64: mm: mark fault_info __ro_after_init

From: Mark Rutland
Date: Wed Mar 29 2017 - 07:26:37 EST


On Tue, Mar 28, 2017 at 02:34:25PM -0700, Doug Berger wrote:
> The fault_info table must be made writeable to allow installation
> of custom memory abort handlers, but it can be made read-only
> after initialization to provide some protection.
>
> Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>

Thanks for putting this together. I agree that making this RO is good.

However, I also think that we should not allow arbitrary hooking of
fault codes, and thus this can be const.

Thanks,
Mark.

> ---
> arch/arm64/mm/fault.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> index cdf1260f1005..43319ed58a47 100644
> --- a/arch/arm64/mm/fault.c
> +++ b/arch/arm64/mm/fault.c
> @@ -493,7 +493,7 @@ static struct fault_info {
> int sig;
> int code;
> const char *name;
> -} fault_info[] = {
> +} fault_info[] __ro_after_init = {
> { do_bad, SIGBUS, 0, "ttbr address size fault" },
> { do_bad, SIGBUS, 0, "level 1 address size fault" },
> { do_bad, SIGBUS, 0, "level 2 address size fault" },
> --
> 2.12.0
>