On Thu, Aug 01, 2024 at 01:06:38PM +0100, Mark Brown wrote: > diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h > index b11cfb9fdd37..545d54c88520 100644 > --- a/arch/arm64/include/asm/pgtable-prot.h > +++ b/arch/arm64/include/asm/pgtable-prot.h > @@ -144,15 +144,23 @@ static inline bool __pure lpa2_is_enabled(void) > /* 6: PTE_PXN | PTE_WRITE */ > /* 7: PAGE_SHARED_EXEC PTE_PXN | PTE_WRITE | PTE_USER */ > /* 8: PAGE_KERNEL_ROX PTE_UXN */ > -/* 9: PTE_UXN | PTE_USER */ > +/* 9: PAGE_GCS_RO PTE_UXN | PTE_USER */ > /* a: PAGE_KERNEL_EXEC PTE_UXN | PTE_WRITE */ > -/* b: PTE_UXN | PTE_WRITE | PTE_USER */ > +/* b: PAGE_GCS PTE_UXN | PTE_WRITE | PTE_USER */ > /* c: PAGE_KERNEL_RO PTE_UXN | PTE_PXN */ > /* d: PAGE_READONLY PTE_UXN | PTE_PXN | PTE_USER */ > /* e: PAGE_KERNEL PTE_UXN | PTE_PXN | PTE_WRITE */ > /* f: PAGE_SHARED PTE_UXN | PTE_PXN | PTE_WRITE | PTE_USER */ > > +#define _PAGE_GCS (_PAGE_DEFAULT | PTE_NG | PTE_UXN | PTE_WRITE | PTE_USER) > +#define _PAGE_GCS_RO (_PAGE_DEFAULT | PTE_NG | PTE_UXN | PTE_USER) > + > +#define PAGE_GCS __pgprot(_PAGE_GCS) > +#define PAGE_GCS_RO __pgprot(_PAGE_GCS_RO) > + > #define PIE_E0 ( \ > + PIRx_ELx_PERM(pte_pi_index(_PAGE_GCS), PIE_GCS) | \ > + PIRx_ELx_PERM(pte_pi_index(_PAGE_GCS_RO), PIE_R) | \ > PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY), PIE_X_O) | \ > PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_RX) | \ > PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC), PIE_RWX) | \ > @@ -160,6 +168,8 @@ static inline bool __pure lpa2_is_enabled(void) > PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED), PIE_RW)) > > #define PIE_E1 ( \ > + PIRx_ELx_PERM(pte_pi_index(_PAGE_GCS), PIE_NONE_O) | \ > + PIRx_ELx_PERM(pte_pi_index(_PAGE_GCS_RO), PIE_NONE_O) | \ It's fine to keep PIE_NONE_O here, the kernel wouldn't need to access this memory with unprivileged instructions (it only matters for the futex code using LDXR/STXR). Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
