[ Note: in quoting the patch below, I removed the '-' lines, so the
quoted part is really just all that remains after the patch ]
On Sun, Nov 6, 2022 at 6:54 AM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>
> + if (region_is_misaligned(md)) {
> + static bool __initdata code_is_misaligned;
> +
> /*
> + * Regions that are not aligned to the OS page size cannot be
> + * mapped with strict permissions, as those might interfere
> + * with the permissions that are needed by the adjacent
> + * region's mapping. However, if we haven't encountered any
> + * misaligned runtime code regions so far, we can safely use
> + * non-executable permissions for non-code regions.
> */
> + code_is_misaligned |= (type == EFI_RUNTIME_SERVICES_CODE);
> +
> + return code_is_misaligned ? pgprot_val(PAGE_KERNEL_EXEC)
> + : pgprot_val(PAGE_KERNEL);
> + }
Ok, this seems like a nice improvement, in how it only does
PAGE_KERNEL_EXEC if any of the regions end up being code.
At the same time this is a much bigger change than just changing the
WARN_ONCE() to pr_warn_once(), so rather than me applying it directly
to my tree, I think I'd prefer it to go through the proper channels
and the usual way.
I'll still apply it to my private "this is the tree I actually boot on
my M2" testing tree, since that has all the other Asahi patches too.
That way I won't see the warning myself on that machine.
So "Acked-by" on the patch, and I hope I'll see it with a future arm64
or EFI pull request (and I'll holler loudly if it actually causes any
issues on my M2, but I obviously don't expect it to)
Thanks,
Linus
