Re: [PATCH v2] mseal sysmap: enable LoongArch

[Liam R. Howlett]

* WangYuli <wangyuli@xxxxxxxxxxxxx> [250415 11:41]:
> Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on LoongArch,
> covering the vdso.
> 
> Link: https://lore.kernel.org/all/25bad37f-273e-4626-999c-e1890be96182@lucifer.local/
> Tested-by: Yuli Wang <wangyuli@xxxxxxxxxxxxx>
> Signed-off-by: Yuli Wang <wangyuli@xxxxxxxxxxxxx>

Acked-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>

> ---
> Changelog:
>  *v1->v2: Modify mseal_sys_mappings/arch-support.txt.
> ---
>  .../features/core/mseal_sys_mappings/arch-support.txt         | 2 +-
>  Documentation/userspace-api/mseal.rst                         | 2 +-
>  arch/loongarch/Kconfig                                        | 1 +
>  arch/loongarch/kernel/vdso.c                                  | 4 +++-
>  4 files changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/features/core/mseal_sys_mappings/arch-support.txt b/Documentation/features/core/mseal_sys_mappings/arch-support.txt
> index c6cab9760d57..a3c24233eb9b 100644
> --- a/Documentation/features/core/mseal_sys_mappings/arch-support.txt
> +++ b/Documentation/features/core/mseal_sys_mappings/arch-support.txt
> @@ -12,7 +12,7 @@
>      |       arm64: |  ok  |
>      |        csky: |  N/A |
>      |     hexagon: |  N/A |
> -    |   loongarch: | TODO |
> +    |   loongarch: |  ok  |
>      |        m68k: |  N/A |
>      |  microblaze: |  N/A |
>      |        mips: | TODO |
> diff --git a/Documentation/userspace-api/mseal.rst b/Documentation/userspace-api/mseal.rst
> index 1dabfc29be0d..ef733f69003d 100644
> --- a/Documentation/userspace-api/mseal.rst
> +++ b/Documentation/userspace-api/mseal.rst
> @@ -144,7 +144,7 @@ Use cases
>    architecture.
>  
>    The following architectures currently support this feature: x86-64, arm64,
> -  and s390.
> +  loongarch and s390.
>  
>    WARNING: This feature breaks programs which rely on relocating
>    or unmapping system mappings. Known broken software at the time
> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> index 067c0b994648..54ed5b59a690 100644
> --- a/arch/loongarch/Kconfig
> +++ b/arch/loongarch/Kconfig
> @@ -69,6 +69,7 @@ config LOONGARCH
>  	select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
>  	select ARCH_SUPPORTS_LTO_CLANG
>  	select ARCH_SUPPORTS_LTO_CLANG_THIN
> +	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
>  	select ARCH_SUPPORTS_NUMA_BALANCING
>  	select ARCH_SUPPORTS_RT
>  	select ARCH_USE_BUILTIN_BSWAP
> diff --git a/arch/loongarch/kernel/vdso.c b/arch/loongarch/kernel/vdso.c
> index 10cf1608c7b3..7b888d9085a0 100644
> --- a/arch/loongarch/kernel/vdso.c
> +++ b/arch/loongarch/kernel/vdso.c
> @@ -105,7 +105,9 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
>  
>  	vdso_addr = data_addr + VVAR_SIZE;
>  	vma = _install_special_mapping(mm, vdso_addr, info->size,
> -				       VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
> +				       VM_READ | VM_EXEC |
> +				       VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC |
> +				       VM_SEALED_SYSMAP,
>  				       &info->code_mapping);
>  	if (IS_ERR(vma)) {
>  		ret = PTR_ERR(vma);
> -- 
> 2.49.0
>