Re: [PATCH 2/3] x86:add missing CONFIG_STRICT_KERNEL_RWX for mark_rodata_ro

[Ingo Molnar]

* nixiaoming <nixiaoming@xxxxxxxxxx> wrote:

> mark_rodata_ro is only called by the function mark_readonly
> when CONFIG_STRICT_KERNEL_RWX=y
> 
> if CONFIG_STRICT_KERNEL_RWX is not set
> a compile warning may be triggered: unused function
> 
> Signed-off-by: nixiaoming <nixiaoming@xxxxxxxxxx>
> ---
>  arch/x86/mm/init_32.c | 2 ++
>  arch/x86/mm/init_64.c | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
> index c893c6a..121c567 100644
> --- a/arch/x86/mm/init_32.c
> +++ b/arch/x86/mm/init_32.c
> @@ -920,6 +920,7 @@ static void mark_nxdata_nx(void)
>  	set_pages_nx(virt_to_page(start), size >> PAGE_SHIFT);
>  }
>  
> +#ifdef CONFIG_STRICT_KERNEL_RWX
>  void mark_rodata_ro(void)
>  {
>  	unsigned long start = PFN_ALIGN(_text);
> @@ -957,3 +958,4 @@ void mark_rodata_ro(void)
>  	if (__supported_pte_mask & _PAGE_NX)
>  		debug_checkwx();
>  }
> +#endif /*end of CONFIG_STRICT_KERNEL_RWX*/
> diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
> index 0a40060..1b7a1a7 100644
> --- a/arch/x86/mm/init_64.c
> +++ b/arch/x86/mm/init_64.c
> @@ -1245,6 +1245,7 @@ void set_kernel_text_ro(void)
>  	set_memory_ro(start, (end - start) >> PAGE_SHIFT);
>  }
>  
> +#ifdef CONFIG_STRICT_KERNEL_RWX
>  void mark_rodata_ro(void)
>  {
>  	unsigned long start = PFN_ALIGN(_text);
> @@ -1298,6 +1299,7 @@ void mark_rodata_ro(void)
>  	 */
>  	pti_clone_kernel_text();
>  }
> +#endif

NAK, this is very ugly and the changelog doesn't appear to be true: the build 
warning does not trigger in the default build, correct?

Thanks,

	Ingo