From 7bafbe47ebc5f13d6216822277bd6453b73187f0 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Fri, 22 Jun 2018 10:25:25 +0100
Subject: [PATCH] arm64: kpti: Use early_param for kpti= command-line option

Git-commit: b5b7dd647f2d21b93f734ce890671cd908e69b0a
Patch-mainline: v4.18-rc2
References: bsc#1103220

We inspect __kpti_forced early on as part of the cpufeature enable
callback which remaps the swapper page table using non-global entries.

Ensure that __kpti_forced has been updated to reflect the kpti=
command-line option before we start using it.

Fixes: ea1e3de85e94 ("arm64: entry: Add fake CPU feature for unmapping the kernel at EL0")
Cc: <stable@vger.kernel.org> # 4.16.x-
Reported-by: Wei Xu <xuwei5@hisilicon.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 arch/arm64/kernel/cpufeature.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -933,7 +933,7 @@ static int __init parse_kpti(char *str)
 	__kpti_forced = enabled ? 1 : -1;
 	return 0;
 }
-__setup("kpti=", parse_kpti);
+early_param("kpti", parse_kpti);
 #endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
 
 static void cpu_copy_el2regs(const struct arm64_cpu_capabilities *__unused)