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| author | Mark Rutland <mark.rutland@arm.com> | 2020-12-02 16:15:58 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-12-02 22:49:11 +0300 |
| commit | 1517c4facf2e66401394998dba1ee236fd261310 (patch) | |
| tree | bb0d14d121fc351344d4143ff53f4099ee943978 /arch/arm64 | |
| parent | 7cf283c7bd6260ae43a74cd213f5ec9d665a19b5 (diff) | |
| download | linux-1517c4facf2e66401394998dba1ee236fd261310.tar.xz | |
arm64: uaccess: remove vestigal UAO support
Now that arm64 no longer uses UAO, remove the vestigal feature detection
code and Kconfig text.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201202131558.39270-13-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/Kconfig | 21 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpucaps.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 11 |
3 files changed, 0 insertions, 33 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 6fae3ec1f2b6..8d13b9135634 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1427,27 +1427,6 @@ endmenu 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 diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index ab3bec7a5a4d..a7242ef2a2cd 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -16,7 +16,6 @@ #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 diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index d09bdc60a8e3..cf09bac80adb 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1764,17 +1764,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .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", |