4.9-stable review patch. If anyone has any objections, please let me know.
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From: Will Deacon will.deacon@arm.com
commit b5b7dd647f2d21b93f734ce890671cd908e69b0a upstream.
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: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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 @@ -826,7 +826,7 @@ 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 const struct arm64_cpu_capabilities arm64_features[] = {