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authorGravatar Joey Gouly <joey.gouly@arm.com> 2023-06-06 15:58:50 +0100
committerGravatar Catalin Marinas <catalin.marinas@arm.com> 2023-06-06 16:52:41 +0100
commitf0af339fc408a55c9f48f5d9ca47059ef1eb36b8 (patch)
treef71ee516598e602503bfcfea30789697cfdbcbca /arch/arm64/include/asm/kernel-pgtable.h
parentKVM: arm64: expose ID_AA64MMFR3_EL1 to guests (diff)
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arm64: add PTE_UXN/PTE_WRITE to SWAPPER_*_FLAGS
With PIE enabled, the swapper PTEs would have a Permission Indirection Index (PIIndex) of 0. A PIIndex of 0 is not currently used by any other PTEs. To avoid using index 0 specifically for the swapper PTEs, mark them as PTE_UXN and PTE_WRITE, so that they map to a PAGE_KERNEL_EXEC equivalent. This also adds PTE_WRITE to KPTI_NG_PTE_FLAGS, which was tested by booting with kpti=on. Signed-off-by: Joey Gouly <joey.gouly@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20230606145859.697944-12-joey.gouly@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/kernel-pgtable.h')
-rw-r--r--arch/arm64/include/asm/kernel-pgtable.h8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h
index 186dd7f85b14..577773870b66 100644
--- a/arch/arm64/include/asm/kernel-pgtable.h
+++ b/arch/arm64/include/asm/kernel-pgtable.h
@@ -107,14 +107,14 @@
/*
* Initial memory map attributes.
*/
-#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
-#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
+#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED | PTE_UXN)
+#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S | PTE_UXN)
#ifdef CONFIG_ARM64_4K_PAGES
-#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS)
+#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS | PTE_WRITE)
#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PMD_SECT_RDONLY)
#else
-#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS)
+#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS | PTE_WRITE)
#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY)
#endif