[PATCH v9 4/7] mseal sysmap: enable arm64

[jeffxu]

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>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Reviewed-by: Kees Cook <kees@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