From: Liu Song <liusong@linux.alibaba.com>
To: catalin.marinas@arm.com, will@kernel.org
Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] arm64: cpufeature: make sure cpu_mitigations_off then kpti off
Date: Thu, 16 Jun 2022 20:35:38 +0800 [thread overview]
Message-ID: <1655382938-126283-1-git-send-email-liusong@linux.alibaba.com> (raw)
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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next reply other threads:[~2022-06-16 12:37 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-16 12:35 Liu Song [this message]
2022-06-23 17:27 ` [PATCH] arm64: cpufeature: make sure cpu_mitigations_off then kpti off Will Deacon
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