Re: [RFC PATCH 2/3] efi/loongarch: Randomize kernel preferred address for KASLR

[Lisa Robinson]

Hi Rui

> diff --git a/drivers/firmware/efi/libstub/loongarch.c b/drivers/firmware/efi/libstub/loongarch.c
> index 9825f5218137..80ba7d69e1b3 100644
> --- a/drivers/firmware/efi/libstub/loongarch.c
> +++ b/drivers/firmware/efi/libstub/loongarch.c
> @@ -38,6 +38,21 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map, void *priv)
>  	return EFI_SUCCESS;
>  }
>  
> +unsigned long efi_get_kimg_kaslr_address(void)
> +{
> +	unsigned int random_offset = 0;
> +
> +#ifdef CONFIG_RANDOMIZE_BASE
> +	if (!efi_nokaslr) {
> +		efi_get_random_bytes(sizeof(random_offset), (u8 *)&random_offset);
> +		random_offset ^= (rdtime_l() << 16);

random_offset &= ~(efi_get_kimg_min_align() - 1);

> +		random_offset &= (CONFIG_RANDOMIZE_BASE_MAX_OFFSET - 1);
> +	}
> +#endif
> +
> +	return PHYSADDR(VMLINUX_LOAD_ADDRESS) + random_offset;
> +}
> +
>  unsigned long __weak kernel_entry_address(unsigned long kernel_addr,
>  		efi_loaded_image_t *image)
>  {

--
Lisa