Subject: [PATCH RFC v8 03/24] arm64: mm: Enable overlays for all EL1 indirect permissions

From: Kevin Brodsky <[email-masked]>
Date: Tue, 26 May 2026 12:15:52 +0100

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.

Signed-off-by: Kevin Brodsky <[email-masked]>
---
 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