menu "ARMv8.2 architectural features"
-config ARM64_UAO
- bool "Enable support for User Access Override (UAO)"
- default y
- help
- User Access Override (UAO; part of the ARMv8.2 Extensions)
- causes the 'unprivileged' variant of the load/store instructions to
- be overridden to be privileged.
-
- This option changes get_user() and friends to use the 'unprivileged'
- variant of the load/store instructions. This ensures that user-space
- really did have access to the supplied memory. When addr_limit is
- set to kernel memory the UAO bit will be set, allowing privileged
- access to kernel memory.
-
- Choosing this option will cause copy_to_user() et al to use user-space
- memory permissions.
-
- The feature is detected at runtime, the kernel will use the
- regular load/store instructions if the cpu does not implement the
- feature.
-
config ARM64_PMEM
bool "Enable support for persistent memory"
select ARCH_HAS_PMEM_API
#define ARM64_WORKAROUND_CAVIUM_23154 6
#define ARM64_WORKAROUND_834220 7
#define ARM64_HAS_NO_HW_PREFETCH 8
-#define ARM64_HAS_UAO 9
#define ARM64_HAS_VIRT_HOST_EXTN 11
#define ARM64_WORKAROUND_CAVIUM_27456 12
#define ARM64_HAS_32BIT_EL0 13
.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
.matches = has_no_hw_prefetch,
},
-#ifdef CONFIG_ARM64_UAO
- {
- .desc = "User Access Override",
- .capability = ARM64_HAS_UAO,
- .type = ARM64_CPUCAP_SYSTEM_FEATURE,
- .matches = has_cpuid_feature,
- .sys_reg = SYS_ID_AA64MMFR2_EL1,
- .field_pos = ID_AA64MMFR2_UAO_SHIFT,
- .min_field_value = 1,
- },
-#endif /* CONFIG_ARM64_UAO */
#ifdef CONFIG_ARM64_VHE
{
.desc = "Virtualization Host Extensions",