[PATCH RFC v8 03/24] arm64: mm: Enable overlays for all EL1 indirect permissions
Kevin Brodsky
kevin.brodsky at arm.com
Tue May 26 04:15:52 PDT 2026
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 <kevin.brodsky at arm.com>
---
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
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