diff options
| author | Joey Gouly <joey.gouly@arm.com> | 2023-06-06 15:58:54 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2023-06-06 16:52:41 +0100 |
| commit | eeda243dfeb996fe236c624796630c16237a18d6 (patch) | |
| tree | 03c6e1643dcd961fc8a9d2f7c6d6aa530efc7f9b /arch/arm64/include/asm | |
| parent | 7df7170965a28c61f80a57b655b0cc10adb88ab9 (diff) | |
arm64: add encodings of PIRx_ELx registers
The encodings used in the permission indirection registers means that the
values that Linux puts in the PTEs do not need to be changed.
The E0 values are replicated in E1, with the execute permissions removed.
This is needed as the futex operations access user mappings with privileged
loads/stores.
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230606145859.697944-16-joey.gouly@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm')
| -rw-r--r-- | arch/arm64/include/asm/pgtable-hwdef.h | 8 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable-prot.h | 50 |
2 files changed, 58 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index f658aafc47df..e4944d517c99 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -171,6 +171,14 @@ #define PTE_ATTRINDX_MASK (_AT(pteval_t, 7) << 2) /* + * PIIndex[3:0] encoding (Permission Indirection Extension) + */ +#define PTE_PI_IDX_0 6 /* AP[1], USER */ +#define PTE_PI_IDX_1 51 /* DBM */ +#define PTE_PI_IDX_2 53 /* PXN */ +#define PTE_PI_IDX_3 54 /* UXN */ + +/* * Memory Attribute override for Stage-2 (MemAttr[3:0]) */ #define PTE_S2_MEMATTR(t) (_AT(pteval_t, (t)) << 2) diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index a45af0a22b25..eed814b00a38 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -107,4 +107,54 @@ extern bool arm64_use_ng_mappings; #endif /* __ASSEMBLY__ */ +#define pte_pi_index(pte) ( \ + ((pte & BIT(PTE_PI_IDX_3)) >> (PTE_PI_IDX_3 - 3)) | \ + ((pte & BIT(PTE_PI_IDX_2)) >> (PTE_PI_IDX_2 - 2)) | \ + ((pte & BIT(PTE_PI_IDX_1)) >> (PTE_PI_IDX_1 - 1)) | \ + ((pte & BIT(PTE_PI_IDX_0)) >> (PTE_PI_IDX_0 - 0))) + +/* + * Page types used via Permission Indirection Extension (PIE). PIE uses + * the USER, DBM, PXN and UXN bits to to generate an index which is used + * to look up the actual permission in PIR_ELx and PIRE0_EL1. We define + * combinations we use on non-PIE systems with the same encoding, for + * convenience these are listed here as comments as are the unallocated + * encodings. + */ + +/* 0: PAGE_DEFAULT */ +/* 1: PTE_USER */ +/* 2: PTE_WRITE */ +/* 3: PTE_WRITE | PTE_USER */ +/* 4: PAGE_EXECONLY PTE_PXN */ +/* 5: PAGE_READONLY_EXEC PTE_PXN | PTE_USER */ +/* 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 */ +/* a: PAGE_KERNEL_EXEC PTE_UXN | PTE_WRITE */ +/* b: 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 PIE_E0 ( \ + 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) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY), PIE_R) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED), PIE_RW)) + +#define PIE_E1 ( \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY), PIE_NONE_O) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_R) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC), PIE_RW) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY), PIE_R) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED), PIE_RW) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_ROX), PIE_RX) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_EXEC), PIE_RWX) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_RO), PIE_R) | \ + PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL), PIE_RW)) + #endif /* __ASM_PGTABLE_PROT_H */ |