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| author |   Mark Rutland <mark.rutland@arm.com> | 2020-12-02 13:15:57 +0000 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2020-12-02 19:49:11 +0000 |
| commit | 7cf283c7bd6260ae43a74cd213f5ec9d665a19b5 (patch) | |
| tree | 5545af2e5ab25dfc021e79ab6ab140a7d7ad4b4f /arch/arm64/kernel | |
| parent | arm64: uaccess: remove addr_limit_user_check() (diff) | |
| download | linux-dev-7cf283c7bd6260ae43a74cd213f5ec9d665a19b5.tar.xz linux-dev-7cf283c7bd6260ae43a74cd213f5ec9d665a19b5.zip | |
arm64: uaccess: remove redundant PAN toggling
Some code (e.g. futex) needs to make privileged accesses to userspace
memory, and uses uaccess_{enable,disable}_privileged() in order to
permit this. All other uaccess primitives use LDTR/STTR, and never need
to toggle PAN.
Remove the redundant PAN toggling.
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/20201202131558.39270-12-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 17 |
1 files changed, 0 insertions, 17 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index ddca55fb79f5..d09bdc60a8e3 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -153,10 +153,6 @@ EXPORT_SYMBOL(cpu_hwcap_keys); .width = 0, \ } -/* meta feature for alternatives */ -static bool __maybe_unused -cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused); - static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap); static bool __system_matches_cap(unsigned int n); @@ -1779,13 +1775,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .min_field_value = 1, }, #endif /* CONFIG_ARM64_UAO */ -#ifdef CONFIG_ARM64_PAN - { - .capability = ARM64_ALT_PAN_NOT_UAO, - .type = ARM64_CPUCAP_SYSTEM_FEATURE, - .matches = cpufeature_pan_not_uao, - }, -#endif /* CONFIG_ARM64_PAN */ #ifdef CONFIG_ARM64_VHE { .desc = "Virtualization Host Extensions", @@ -2736,12 +2725,6 @@ void __init setup_cpu_features(void) ARCH_DMA_MINALIGN); } -static bool __maybe_unused -cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused) -{ - return (__system_matches_cap(ARM64_HAS_PAN) && !__system_matches_cap(ARM64_HAS_UAO)); -} - static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap) { cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); |