[PATCH RFC v9 03/25] arm64: mm: Enable overlays for all EL1 indirect permissions
From: Kevin Brodsky <hidden>
Date: 2026-08-18 14:11:52
Also in:
linux-hardening, linux-mm
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
In preparation of using POE inside the kernel, enable "Overlay applied" for kernel memory types in PIR_EL1. This ensures that the permissions set in POR_EL1 affect all kernel mappings. User memory types must be left untouched (overlays not applied) because any privileged access to user memory (e.g. futex atomic without FEAT_LSUI) would then be mistakenly checked against POR_EL1. Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Kevin Brodsky <redacted> --- arch/arm64/include/asm/pgtable-prot.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 212ce1b02e15..d4d45ab86a5a 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h@@ -183,9 +183,9 @@ static inline bool __pure lpa2_is_enabled(void) PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_SHARED_EXEC), PIE_RW) | \ PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_READONLY), PIE_R) | \ PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_SHARED), PIE_RW) | \ - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_ROX), PIE_RX) | \ - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_EXEC), PIE_RWX) | \ - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_RO), PIE_R) | \ - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL), PIE_RW)) + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_ROX), PIE_RX_O) | \ + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_EXEC), PIE_RWX_O) | \ + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_RO), PIE_R_O) | \ + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL), PIE_RW_O)) #endif /* __ASM_PGTABLE_PROT_H */
--
2.51.2