Messages in this thread Patch in this message | | | From | Liu Song <> | Subject | [PATCH] arm64: cpufeature: make sure cpu_mitigations_off then kpti off | Date | Thu, 16 Jun 2022 20:35:38 +0800 |
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From: Liu Song <liusong@linux.alibaba.com>
If kaslr is enabled, kpti cannot be turned off even if "mitigations=off", adjust the code order to ensure that kpti is off when "mitigations=off".
Signed-off-by: Liu Song <liusong@linux.alibaba.com> --- arch/arm64/kernel/cpufeature.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 42ea2bd..27d4850 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1616,6 +1616,11 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, __kpti_forced = -1; } + if (cpu_mitigations_off() && !__kpti_forced) { + str = "mitigations=off"; + __kpti_forced = -1; + } + /* Useful for KASLR robustness */ if (kaslr_requires_kpti()) { if (!__kpti_forced) { @@ -1624,11 +1629,6 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, } } - if (cpu_mitigations_off() && !__kpti_forced) { - str = "mitigations=off"; - __kpti_forced = -1; - } - if (!IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0)) { pr_info_once("kernel page table isolation disabled by kernel configuration\n"); return false; -- 1.8.3.1
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