Re: [PATCH v8 4/7] mseal sysmap: enable arm64

[Lorenzo Stoakes]

On Mon, Mar 03, 2025 at 05:09:18AM +0000, jeffxu@xxxxxxxxxxxx wrote:
> From: Jeff Xu <jeffxu@xxxxxxxxxxxx>
>
> Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on arm64, covering
> the vdso, vvar, and compat-mode vectors and sigpage mappings.
>
> Production release testing passes on Android and Chrome OS.
>
> Signed-off-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>

LGTM so:

Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>

> ---
>  arch/arm64/Kconfig       |  1 +
>  arch/arm64/kernel/vdso.c | 12 ++++++++----
>  2 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 940343beb3d4..282d6cb13cfb 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -38,6 +38,7 @@ config ARM64
>  	select ARCH_HAS_KEEPINITRD
>  	select ARCH_HAS_MEMBARRIER_SYNC_CORE
>  	select ARCH_HAS_MEM_ENCRYPT
> +	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
>  	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
>  	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
>  	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index e8ed8e5b713b..69d2b5ceb092 100644
> --- a/arch/arm64/kernel/vdso.c
> +++ b/arch/arm64/kernel/vdso.c
> @@ -198,7 +198,8 @@ static int __setup_additional_pages(enum vdso_abi abi,
>  	}
>
>  	ret = _install_special_mapping(mm, vdso_base, VVAR_NR_PAGES * PAGE_SIZE,
> -				       VM_READ|VM_MAYREAD|VM_PFNMAP,
> +				       VM_READ|VM_MAYREAD|VM_PFNMAP|
> +				       VM_SEALED_SYSMAP,
>  				       &vvar_map);
>  	if (IS_ERR(ret))
>  		goto up_fail;
> @@ -210,7 +211,8 @@ static int __setup_additional_pages(enum vdso_abi abi,
>  	mm->context.vdso = (void *)vdso_base;
>  	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
>  				       VM_READ|VM_EXEC|gp_flags|
> -				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
> +				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
> +				       VM_SEALED_SYSMAP,
>  				       vdso_info[abi].cm);
>  	if (IS_ERR(ret))
>  		goto up_fail;
> @@ -336,7 +338,8 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
>  	 */
>  	ret = _install_special_mapping(mm, AARCH32_VECTORS_BASE, PAGE_SIZE,
>  				       VM_READ | VM_EXEC |
> -				       VM_MAYREAD | VM_MAYEXEC,
> +				       VM_MAYREAD | VM_MAYEXEC |
> +				       VM_SEALED_SYSMAP,
>  				       &aarch32_vdso_maps[AA32_MAP_VECTORS]);
>
>  	return PTR_ERR_OR_ZERO(ret);
> @@ -359,7 +362,8 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)
>  	 */
>  	ret = _install_special_mapping(mm, addr, PAGE_SIZE,
>  				       VM_READ | VM_EXEC | VM_MAYREAD |
> -				       VM_MAYWRITE | VM_MAYEXEC,
> +				       VM_MAYWRITE | VM_MAYEXEC |
> +				       VM_SEALED_SYSMAP,
>  				       &aarch32_vdso_maps[AA32_MAP_SIGPAGE]);
>  	if (IS_ERR(ret))
>  		goto out;
> --
> 2.48.1.711.g2feabab25a-goog
>