Re: [PATCH v8 1/4] x86/KASLR: Clarify identity map interface

[Ingo Molnar]

* Kees Cook <keescook@xxxxxxxxxxxx> wrote:

> +/*
> + * Mapping information structure passed to kernel_ident_mapping_init().
> + * Due to relocation, pointers must be assigned at run time not build time.
> + */
> +static struct x86_mapping_info mapping_info = {
> +	.pmd_flag       = __PAGE_KERNEL_LARGE_EXEC,
> +};

> +void initialize_identity_maps(void)
>  {
> +	/* Init mapping_info with run-time function/buffer pointers. */
> +	mapping_info.alloc_pgt_page = alloc_pgt_page;
> +	mapping_info.context = &pgt_data;

Could you please outline the precise failure mode? What gets executed when, which 
pointer gets relocated and which not, and exactly when does it pose a problem, 
etc.

Thanks,

	Ingo