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

jeffxu
2025-03-03T05:09:43Z

From: Jeff Xu <jeffxu@chromium.org>

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@chromium.org>
---
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