On Tue, 6 Sept 2022 at 12:41, Evgeniy Baskov <baskov@xxxxxxxxx> wrote:
>
> Avoid creating sections with maximal privileges to prepare for W^X
privileges
> implementation. Align sections on page size (4KB) to allow protecting
> them in page table.
>
in the page tables.
> Signed-off-by: Evgeniy Baskov <baskov@xxxxxxxxx>
> ---
> arch/x86/kernel/vmlinux.lds.S | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index 15f29053cec4..6587e0201b50 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -102,12 +102,11 @@ jiffies = jiffies_64;
> PHDRS {
> text PT_LOAD FLAGS(5); /* R_E */
> data PT_LOAD FLAGS(6); /* RW_ */
> -#ifdef CONFIG_X86_64
> -#ifdef CONFIG_SMP
> +#if defined(CONFIG_X86_64) && defined(CONFIG_SMP)
> percpu PT_LOAD FLAGS(6); /* RW_ */
> #endif
> - init PT_LOAD FLAGS(7); /* RWE */
> -#endif
> + inittext PT_LOAD FLAGS(5); /* R_E */
> + init PT_LOAD FLAGS(6); /* RW_ */
Please explain in the commit log how this change affects X86_32
> note PT_NOTE FLAGS(0); /* ___ */
> }
>
> @@ -226,9 +225,10 @@ SECTIONS
> #endif
>
> INIT_TEXT_SECTION(PAGE_SIZE)
> -#ifdef CONFIG_X86_64
> - :init
> -#endif
> + :inittext
> +
> + . = ALIGN(PAGE_SIZE);
> +
>
> /*
> * Section for code used exclusively before alternatives are run. All
> @@ -240,6 +240,7 @@ SECTIONS
> .altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) {
> *(.altinstr_aux)
> }
> + :init
>
> INIT_DATA_SECTION(16)
>
> --
> 2.35.1
>
