[PATCH v8 3/7] mseal sysmap: enable x86-64

jeffxu
2025-03-03T05:09:40Z

From: Jeff Xu <jeffxu@chromium.org>

Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on x86-64,
covering the vdso, vvar, vvar_vclock.

Production release testing passes on Android and Chrome OS.

Signed-off-by: Jeff Xu <jeffxu@chromium.org>
---
arch/x86/Kconfig | 1 +
arch/x86/entry/vdso/vma.c | 7 ++++---
2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index be2c311f5118..c6f9ebcbe009 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -26,6 +26,7 @@ config X86_64
depends on 64BIT
# Options that are inherently 64-bit kernel only:
select ARCH_HAS_GIGANTIC_PAGE
+ select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
select ARCH_SUPPORTS_PER_VMA_LOCK
select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 39e6efc1a9ca..a4f312495de1 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -268,7 +268,8 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
text_start,
image->size,
VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+ VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
+ VM_SEALED_SYSMAP,
&vdso_mapping);

if (IS_ERR(vma)) {
@@ -280,7 +281,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
addr,
(__VVAR_PAGES - VDSO_NR_VCLOCK_PAGES) * PAGE_SIZE,
VM_READ|VM_MAYREAD|VM_IO|VM_DONTDUMP|
- VM_PFNMAP,
+ VM_PFNMAP|VM_SEALED_SYSMAP,
&vvar_mapping);

if (IS_ERR(vma)) {
@@ -293,7 +294,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
addr + (__VVAR_PAGES - VDSO_NR_VCLOCK_PAGES) * PAGE_SIZE,
VDSO_NR_VCLOCK_PAGES * PAGE_SIZE,
VM_READ|VM_MAYREAD|VM_IO|VM_DONTDUMP|
- VM_PFNMAP,
+ VM_PFNMAP|VM_SEALED_SYSMAP,
&vvar_vclock_mapping);

if (IS_ERR(vma)) {
--
2.48.1.711.g2feabab25a-goog